ORCID Profile
0000-0003-2469-9023
Current Organisations
Royal Australasian College of Physicians
,
Auckland City Hospital
,
The University of Auckland
,
University of Otago Dunedin School of Medicine
,
University of Melbourne
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Publications
Visual Assessment of Perfusion-Diffusion Mismatch Is Inadequate to Select Patients for Thrombolysis
Publisher: S. Karger AG
Date: 2010
DOI: 10.1159/000311080
Abstract: i Background: /i For MR perfusion-diffusion mismatch to be clinically useful as a means of selecting patients for thrombolysis, it needs to occur in real time at the MRI console. Visual mismatch assessment has been used clinically and in trials but has not been systematically validated. We compared the accuracy of visually rating console-generated images with offline volumetric measurements using data from the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). i Methods: /i Perfusion time-to-peak (TTP) and diffusion-weighted images (DWI) (as generated by commercial MRI console software) and T sub max /sub perfusion maps (which required offline calculation) were visually rated. Perfusion-diffusion mismatch, defined as a ratio of perfusion:diffusion lesion volume of .2, was independently scored by 1 expert and 2 inexperienced raters blinded to calculated volumes and clinical information. Visual mismatch was compared with region-of-interest-based volumetric calculation, which was used as the gold standard. i Results: /i Volumetric calculation demonstrated perfusion-diffusion mismatch in 85/99 patients. Visual TTP-DWI mismatch was correctly classified by the experienced rater in 82% of the cases (sensitivity: 0.86 specificity: 0.54) compared to 73% for the inexperienced raters (sensitivity: 0.75 specificity: 0.57). The interrater reliability for TTP-DWI mismatch was moderate (ĸ = 0.50). Visual T sub max /sub -DWI mismatch performed better (agreement – 93 and 87%, sensitivity – 95 and 88%, specificity – 77 and 82% for the experienced and inexperienced raters, respectively). i Conclusions: /i The assessment of visual TTP-DWI mismatch at the MRI console is insufficiently reliable for use in clinical trials. Differences in perfusion analysis technique and visual inaccuracies combine to make visual TTP-DWI mismatch substantially different to volumetric T sub max /sub -DWI mismatch. Automated software that applies perfusion thresholds may improve the reproducibility of real-time mismatch assessment.
Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial
Publisher: BMJ
Date: 15-01-2008
Intra-arterial thrombolysis for hyperacute stroke - Reply
Publisher: Elsevier BV
Date: 09-2000
Inhibition of NMDA receptor function with an anti-GluN1-S2 antibody impairs human platelet function and thrombosis
Publisher: Informa UK Limited
Date: 21-02-2017
DOI: 10.1080/09537104.2017.1280149
Abstract: GluN1 is a mandatory component of N-methyl-D-aspartate receptors (NMDARs) best known for their roles in the brain, but with increasing evidence for relevance in peripheral tissues, including platelets. Certain anti-GluN1 antibodies reduce brain infarcts in rodent models of ischaemic stroke. There is also evidence that human anti-GluN1 autoantibodies reduce neuronal damage in stroke patients, but the underlying mechanism is unclear. This study investigated whether anti-GluN1-mediated neuroprotection involves inhibition of platelet function. Four commercial anti-GluN1 antibodies were screened for their abilities to inhibit human platelet aggregation. Haematological parameters were examined in rats vaccinated with GluN1. Platelet effects of a mouse monoclonal antibody targeting the glycine-binding region of GluN1 (GluN1-S2) were tested in assays of platelet activation, aggregation and thrombus formation. The epitope of anti-GluN1-S2 was mapped and the mechanism of antibody action modelled using crystal structures of GluN1. Our work found that rats vaccinated with GluN1 had a mildly prolonged bleeding time and carried antibodies targeting mostly GluN1-S2. The monoclonal anti-GluN1-S2 antibody (from BD Biosciences) inhibited activation and aggregation of human platelets in the presence of adrenaline, adenosine diphosphate, collagen, thrombin and a protease-activated receptor 1-activating peptide. When human blood was flowed over collagen-coated surfaces, anti-GluN1-S2 impaired thrombus growth and stability. The epitope of anti-GluN1-S2 was mapped to α-helix H located within the glycine-binding clamshell of GluN1, where the antibody binding was computationally predicted to impair opening of the NMDAR channel. Our results indicate that anti-GluN1-S2 inhibits function of human platelets, including dense granule release and thrombus growth. Findings add to the evidence that platelet NMDARs regulate thrombus formation and suggest a novel mechanism by which anti-GluN1 autoantibodies limit stroke-induced neuronal damage.
Transient ischemic attack service provision
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 22-01-2016
Acute hyperglycemia adversely affects stroke outcome: A magnetic resonance imaging and spectroscopy study
Publisher: Wiley
Date: 18-06-2002
DOI: 10.1002/ANA.10241
Abstract: Controversy exists whether acute hyperglycemia is causally associated with worse stroke outcome or simply reflects a more severe stroke. In reversible ischemia models, hyperglycemia is associated with lactic acidosis and conversion of penumbral tissue to infarction. However, the relationship between hyperglycemia, lactic acidosis, and stroke outcome has not been explored in humans. Sixty-three acute stroke patients were prospectively evaluated with serial diffusion-weighted and perfusion-weighted magnetic resonance imaging and acute blood glucose measurements. Patients with hypoperfused at-risk tissue were identified by acute perfusion-diffusion lesion mismatch. As a substudy, acute and subacute magnetic resonance spectroscopy was performed in the 33 most recent patients to assess the relationship between acute blood glucose and lactate production in the ischemic region. In 40 of 63 patients with acute perfusion-diffusion mismatch, acute hyperglycemia was correlated with reduced salvage of mismatch tissue from infarction, greater final infarct size, and worse functional outcome. These correlations were independent of baseline stroke severity, lesion size, and diabetic status. Furthermore, higher acute blood glucose in patients with perfusion-diffusion mismatch was associated with greater acute-subacute lactate production, which, in turn, was independently associated with reduced salvage of mismatch tissue. In contrast, acute blood glucose levels in nonmismatch patients did not independently correlate with outcome measures, nor was there any acute-subacute increase in lactate in this group. Acute hyperglycemia increases brain lactate production and facilitates conversion of hypoperfused at-risk tissue into infarction, which may adversely affect stroke outcome. These findings support the need for randomized controlled trials of aggressive glycemic control in acute stroke.
Postoperative Ischemia and Cognitive Impairment in Cardiac Surgery Patients
Publisher: Elsevier BV
Date: 02-2009
Advanced imaging improves prediction of hemorrhage after stroke thrombolysis
Publisher: Wiley
Date: 26-02-2013
DOI: 10.1002/ANA.23837
Regional Very Low Cerebral Blood Volume Predicts Hemorrhagic Transformation Better Than Diffusion-Weighted Imaging Volume and Thresholded Apparent Diffusion Coefficient in Acute Ischemic Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2010
DOI: 10.1161/STROKEAHA.109.562116
Abstract: Background and Purpose— Currently, diffusion-weighted imaging (DWI) lesion volume is the most useful magnetic resonance imaging predictor of hemorrhagic transformation (HT). Preliminary studies have suggested that very low cerebral blood volume (VLCBV) predicts HT. We compared HT prediction by VLCBV and DWI using data from the EPITHET study. Methods— Normal-percentile CBV values were calculated from the nonstroke hemisphere. Whole-brain masks with CBV thresholds of the , 2.5, 5, and 10th percentiles were created. The volume of tissue with VLCBV was calculated within the acute DWI ischemic lesion. HT was graded as per ECASS criteria. Results— HT occurred in 44 of 91 patients. Parenchymal hematoma (PH) occurred in 13 (4 symptomatic) and asymptomatic hemorrhagic infarction (HI) in 31. The median volume of VLCBV was significantly higher in cases with PH. VLCBV predicted HT better than DWI lesion volume and thresholded apparent diffusion coefficient lesion volume in receiver operating characteristic analysis and logistic regression. A cutpoint at 2 mL VLCBV with the .5th percentile had 100% sensitivity for PH and, in patients treated with tissue plasminogen activator, defined a population with a 43% risk of PH (95% CI, 23% to 66%, likelihood ratio=16). VLCBV remained an independent predictor of PH in multivariate analysis with traditional clinical risk factors for HT. Conclusions— VLCBV predicted HT after thrombolysis better than did DWI or apparent diffusion coefficient volume in this large patient cohort. The advantage was greatest in patients with smaller DWI volumes. Prediction was better in patients who recanalized. If validated in an independent cohort, the addition of VLCBV to prethrombolysis decision making may reduce the incidence of HT.
Ethnic differences in syringomyelia in New Zealand
Publisher: BMJ
Date: 18-05-2006
A template-based procedure for determining white matter integrity in the internal capsule early after stroke
Publisher: Elsevier BV
Date: 2014
Sodium Levels and Outcomes Following Endovascular Thrombectomy for Ischemic Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2022
Abstract: Hyponatremia has been associated with worse outcomes in patients with ischemic stroke. Previous studies measured sodium levels at variable times after stroke onset. Patients treated with endovascular thrombectomy have sodium levels measured close to stroke onset. Our aim was to evaluate the association between admission sodium levels and outcome following endovascular thrombectomy. Consecutive patients undergoing endovascular thrombectomy with admission sodium levels were identified from a prospective registry. The primary outcome was functional independence, defined as a modified Rankin scale score of 0, 1, or 2 at 3 months. Secondary outcomes included early neurological recovery (reduction in National Institutes of Health Stroke Scale score ≥8 points from baseline or score of 0–1 at 24 hours), ordinal shift of modified Rankin scale scores at 3 months, symptomatic intracranial hemorrhage, 7‐day mortality, and 3‐month mortality. A total of 710 patients were included (42.5% women mean±SD age, 66.4±14.9 years). The mean±SD admission sodium level was 139±3 mmol/L. Multivariable logistic regression analysis demonstrated that higher admission sodium level (per 1‐mmol/L increase) was an independent predictor of functional independence (odds ratio [OR], 1.06 [95% CI, 1.01–1.11] P =0.03), early neurological recovery (OR, 1.07 [95% CI, 1.01–1.13] P =0.02), and 3‐month modified Rankin scale scores (OR, 0.94 [95% CI, 0.89–0.99] P =0.02). The Youden optimal prognostic cutoff for functional independence was an admission sodium level of ≥136 mmol/L ( P =0.04). There were no associations between sodium levels and symptomatic intracranial hemorrhage, 7‐day mortality, or 3‐month mortality. Admission sodium levels are an independent predictor of functional outcomes following endovascular thrombectomy. Whether admission sodium levels would be of value in decision‐support tools for endovascular thrombectomy should be evaluated in future studies.
Prevalence and Predictors of 6-Month Fatigue in Patients With Ischemic Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2012
DOI: 10.1161/STROKEAHA.112.660886
Abstract: Although persistent and significant fatigue affects the daily life of stroke survivors, there are no population-based studies examining the prevalence of fatigue in 6-month survivors of ischemic stroke and few studies of predictors of poststroke fatigue. This article examined data from the Auckland Regional Community Stroke study conducted in Auckland, New Zealand, in 2002 to 2003. Presence of fatigue was evaluated at 6 months in 613 patients with ischemic stroke using a Short Form 36 Vitality Score (energy and fatigue) of ≤47. Multivariate logistic regression analysis was used to determine predictors of fatigue development 6 months poststroke. The prevalence of fatigue was 30% (28% in men and 33% in women). There was a clear association between increased prevalence of fatigue and advancing age. The only baseline variables independently associated with an increased risk of developing fatigue at 6 months poststroke were prestroke incontinence and being of New Zealand European ethnicity. Being independent and living alone at baseline were associated with significant reduction in the risk of being fatigued at 6 months poststroke. Severe depression at 6 months was significantly and independently associated with being fatigued. The prevalence of fatigue found in our study is at the lower level of range reported in other studies. The prevalence of fatigue increased with advancing age, as found in most previous studies. Because fatigue can have a negative impact on stroke recovery, particular attention needs to be paid to those who are older, incontinent before stroke, and those who report severe symptoms of depression at 6 months after stroke.
Impact of Body Temperature Before and After Endovascular Thrombectomy for Large Vessel Occlusion Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2020
DOI: 10.1161/STROKEAHA.119.028160
Abstract: In ischemic stroke, body temperature is associated with functional outcome. However, the relationship between temperature and outcome may differ in the intraischemic and postischemic phases of stroke. We aimed to determine whether body temperature before or after endovascular thrombectomy (EVT) for large vessel occlusion stroke is associated with clinical outcomes. Consecutive EVT patients were identified from a prospective registry. Temperature measurements within 24 hours of admission were stratified into pre-EVT (preprocedural and intraprocedural) and post-EVT measurements, which served as surrogates for the intraischemic and postischemic phases of large vessel occlusion stroke, respectively. The primary outcome was functional independence, defined as a modified Rankin Scale score of 0, 1, or 2 at 3 months. Secondary outcomes included the ordinal shift of modified Rankin Scale scores at 3 months, symptomatic intracerebral hemorrhage, and mortality at 3 months. Four hundred thirty-two participants were included (59% men, mean±SD age 65.6±15.7 years). Multivariable logistic regression demonstrated that higher median pre-EVT temperature (per 1°C increase) was an independent predictor of reduced functional independence (odds ratio [OR], 0.66 [95% CI, 0.46–0.94] P =0.02), poorer modified Rankin Scale scores (common OR, 1.42 [95% CI, 1.08–1.85] P =0.01), and increased mortality (OR, 1.65 [95% CI, 1.02–2.69] P =0.04). Peak post-EVT temperature (per 1°C increase) was a significant predictor of elevated modified Rankin Scale scores (common OR, 1.39 [95% CI, 1.03–1.90] P =0.03) and higher mortality (OR, 1.66 [95% CI, 1.04–2.67] P =0.03). In patients with large vessel occlusion stroke treated with EVT, higher body temperatures during both the intraischemic and postischemic phases were associated with poorer clinical outcomes. Future research investigating the maintenance of normothermia or therapeutic hypothermia in patients needing to be transferred from primary to EVT-capable stroke centers could be considered.
Cerebral amyloid angiopathy related inflammation: three case reports and a review
Publisher: BMJ
Date: 09-10-2011
Abstract: Cerebral amyloid angiopathy related inflammation (CAA-I), previously described under various names, is a treatable encephalopathy usually occurring in older adults. Here, three patients are described with histopathologically confirmed CAA-I, and summarised data from the published literature are presented. CAA-I has a characteristic combination of clinical and radiological features. Definite diagnosis requires brain and leptomeningeal biopsy. A favourable response to immunosuppressive therapy is common and treatment without brain biopsy may be considered in selected patients. Diagnostic criteria for CAA-I are proposed.
Priming the motor system enhances the effects of upper limb therapy in chronic stroke
Publisher: Oxford University Press (OUP)
Date: 20-03-2008
DOI: 10.1093/BRAIN/AWN051
Abstract: After stroke, the function of primary motor cortex (M1) between the hemispheres may become unbalanced. Techniques that promote a re-balancing of M1 excitability may prime the brain to be more responsive to rehabilitation therapies and lead to improved functional outcomes. The present study examined the effects of Active-Passive Bilateral Therapy (APBT), a putative movement-based priming strategy designed to reduce intracortical inhibition and increase excitability within the ipsilesional M1. Thirty-two patients with upper limb weakness at least 6 months after stroke were randomized to a 1-month intervention of self-directed motor practice with their affected upper limb (control group) or to APBT for 10-15 min prior to the same motor practice (APBT group). A blinded clinical rater assessed upper limb function at baseline, and immediately and 1 month after the intervention. Transcranial magnetic stimulation was used to assess M1 excitability. Immediately after the intervention, motor function of the affected upper limb improved in both groups (P < 0.005). One month after the intervention, the APBT group had better upper limb motor function than control patients (P < 0.05). The APBT group had increased ipsilesional M1 excitability (P < 0.025), increased transcallosal inhibition from ipsilesional to contralesional M1 (P < 0.01) and increased intracortical inhibition within contralesional M1 (P < 0.005). None of these changes were found in the control group. APBT produced sustained improvements in upper limb motor function in chronic stroke patients and induced specific and sustained changes in motor cortex inhibitory function. We speculate that APBT may have facilitated plastic reorganization in the brain in response to motor therapy. The utility of APBT as an adjuvant to physical therapy warrants further consideration.
Rural versus metropolitan comparison of processes of care in the community‐based management of TIA and minor stroke in Australia (an analysis from the INSIST study)
Publisher: Wiley
Date: 16-11-2022
DOI: 10.1111/AJR.12950
Abstract: To compare processes of care and clinical outcomes of community‐based management of TIAs and minor strokes (TIAMS) between rural and metropolitan Australia. Inception cohort study between 2012 and 2016 with 12‐month follow‐up after index event (sub‐study of INSIST). Hunter and Manning valley regions of New South Wales, within the referral territory of the John Hunter Hospital Acute Neurovascular Clinic (JHHANC). Consecutive patients of 16 participating general practices, presenting with possible TIAMS to either primary or secondary care. Processes of care (referrals, key management processes, time‐based metrics) and clinical outcomes. Of 613 participants with possible TIAMS who completed the baseline interview, 298 were adjudicated as having TIAMS (119 from rural, 179 from metropolitan). Mean age was 72.3 years (SD, 10.7) and 127 (43%) were women. Rural participants were more likely to be managed solely by a general practitioner (GP) than metropolitan participants (34% v 20%) and less likely to be referred to a JHHANC specialist (13% v 38%) or have brain magnetic resonance imaging (MRI) [24% v 51%]. Those rural participants who were referred, also waited longer (both p 0.001). Recurrent stroke, myocardial infarction and death at 12 months were not significantly different between rural and metropolitan participants. Although TIAMS prognosis in rural settings where solely GP care is common is very good, the processes of care in such areas are inferior to metropolitan. This suggests there is further scope to support rural GPs to optimise care of TIAMS patients.
Reducing Ethnic and Geographic Inequities to Optimise New Zealand Stroke Care (REGIONS Care): Protocol for a Nationwide Observational Study (Preprint)
Publisher: JMIR Publications Inc.
Date: 16-11-2020
Abstract: troke systems of care differ between larger urban and smaller rural settings and it is unclear to what extent this may impact on patient outcomes. Ethnicity influences stroke risk factors and care delivery as well as patient outcomes in nonstroke settings. Little is known about the impact of ethnicity on poststroke care, especially in Māori and Pacific populations. ur goal is to describe the protocol for the Reducing Ethnic and Geographic Inequities to Optimise New Zealand Stroke Care (REGIONS Care) study. his large, nationwide observational study assesses the impact of rurality and ethnicity on best practice stroke care access and outcomes involving all 28 New Zealand hospitals caring for stroke patients, by capturing every stroke patient admitted to hospital during the 2017-2018 study period. In addition, it explores current access barriers through consumer focus groups and consumer, carer, clinician, manager, and policy-maker surveys. It also assesses the economic impact of care provided at different types of hospitals and to patients of different ethnicities and explores the cost-efficacy of in idual interventions and care bundles. Finally, it compares manual data collection to routine health administrative data and explores the feasibility of developing outcome models using only administrative data and the cost-efficacy of using additional manually collected registry data. Regarding s le size estimates, in Part 1, Study A, 2400 participants are needed to identify a 10% difference between up to four geographic subgroups at 90% power with an α value of .05 and 10% to 20% loss to follow-up. In Part 1, Study B, a s le of 7645 participants was expected to include an estimated 850 Māori and 419 Pacific patients and to provide over 90% and over 80% power, respectively. Regarding Part 2, 50% of the patient or carer surveys, 40 provider surveys, and 10 focus groups were needed to achieve saturation of themes. The main outcome is the modified Rankin Scale (mRS) score at 3 months. Secondary outcomes include mRS scores EQ-5D-3L (5-dimension, 3-level EuroQol questionnaire) scores stroke recurrence vascular events death readmission at 3, 6, and 12 months cost of care and themes around access barriers. he study is underway, with national and institutional ethics approvals in place. A total of 2379 patients have been recruited for Part 1, Study A 6837 patients have been recruited for Part 1, Study B 10 focus groups have been conducted and 70 surveys have been completed in Part 2. Data collection has essentially been completed, including follow-up assessment however, primary and secondary analyses, data linkage, data validation, and health economics analysis are still underway. he methods of this study may provide the basis for future epidemiological studies that will guide care improvements in other countries and populations. ERR1-10.2196/25374
Abstract P486: Mechanical Embolectomy Using a Novel Telescopic System Featuring a Specialized Delivery and 0.088” Aspiration Catheter for the Treatment of Acute Ischemic Stroke: Preliminary Results of
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2021
DOI: 10.1161/STR.52.SUPPL_1.P486
Abstract: Background: The treatment approach of aspiration rather than use of a stent retriever as first-line therapy is increasingly regarded as standard of care for acute ischemic stroke. Continued technological advances include the ongoing development of aspiration embolectomy catheters that are larger in bore, guided by delivery catheters that are more maneuverable through the tortuous neurovasculature. Methods: SUMMIT NZ (ACTRN12619000890134p) was designed as a prospective, single-arm, open label clinical trial at two sites in New Zealand. Eligible participants were patients presenting with acute ischemic stroke from either anterior or posterior circulation large-vessel occlusion within 24 hours of onset, a National Institutes of Health Stroke Scale Score ≥ 6 and a pre-stroke modified Rankin Score of ≤ 2. A novel tapered tip delivery catheter was specifically designed to deliver 0.070” and 0.088” aspiration catheters telescoped through a specialized 8F 90 cm introducer sheath (Route 92 Medical, Inc. San Mateo, CA). The primary effectiveness endpoint was arterial revascularization as measured by a modified Thrombosis in Cerebrovascular Infarction (mTICI) score of 2b or greater at the end of angiography after all endovascular treatments as adjudicated by an independent core laboratory. The primary safety endpoints were device-related peri-procedural complications such as dissection or perforation, symptomatic Intracranial Cerebral Hemorrhage (SICH) at 24 hours and embolization to a previously uninvolved territory. Results: From September 27, 2019 to June 23, 2020, 18 subjects (mean age 69.5, NIHSSS 15.2, time last known well 6.2 hours) were enrolled with a diagnosis of acute ischemic stroke. Acute occlusion was located in the middle cerebral artery (78%, 14/18) and internal carotid artery (22%, 4/18). Successful revascularization was achieved in 94% (17/18) of subjects. No serious adverse device effects have been reported. Conclusions: Preliminary findings suggest that aspiration first mechanical embolectomy using a novel telescoping system including an 0.088” inner diameter aspiration catheter achieves a high rate of arterial revascularization with an acceptable safety profile. A full report on enrollment and results are to be presented.
Incidence of Transient Ischemic Attack in Auckland, New Zealand, in 2011 to 2012
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2016
DOI: 10.1161/STROKEAHA.116.014010
Abstract: There have been few recent population-based studies reporting the incidence (first ever) and attack rates (incident and recurrent) of transient ischemic attack (TIA). The fourth Auckland Regional Community Stroke study (ARCOS IV) used multiple overlapping case ascertainment methods to identify all hospitalized and nonhospitalized cases of TIA that occurred in people ≥16 years of age usually resident in Auckland (population ≥16 years of age is 1.12 million), during the 12 months from March 1, 2011. All first-ever and recurrent new TIAs (any new TIA 28 days after the index event) during the study period were recorded. There were 785 people with TIA (402 [51.2%] women, mean [SD] age 71.5 [13.8] years) 614 (78%) of European origin, 84 (11%) Māori/Pacific, and 75 (10%) Asian/Other. The annual incidence of TIA was 40 (95% confidence interval, 36–43), and attack rate was 63 (95% confidence interval, 59–68), per 100 000 people, age standardized to the World Health Organization world population. Approximately two thirds of people were known to be hypertensive or were being treated with blood pressure–lowering agents, half were taking antiplatelet agents and just under half were taking lipid-lowering therapy before the index TIA. Two hundred ten (27%) people were known to have atrial fibrillation at the time of the TIA, of whom only 61 (29%) were taking anticoagulant therapy, suggesting a failure to identify or treat atrial fibrillation. This study describes the burden of TIA in an era of aggressive primary and secondary vascular risk factor management. Education programs for medical practitioners and patients around the identification and management of atrial fibrillation are required.
Comparison of Stroke Care Costs in Urban and Nonurban Hospitals and Its Association With Outcomes in New Zealand: A Nationwide Economic Evaluation
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2023
DOI: 10.1161/STROKEAHA.122.040869
Abstract: Although geographical differences in treatment and outcomes after stroke have been described, we lack evidence on differences in the costs of treatment between urban and nonurban regions. Additionally, it is unclear whether greater costs in one setting are justified given the outcomes achieved. We aimed to compare costs and quality-adjusted life years in people with stroke admitted to urban and nonurban hospitals in New Zealand. Observational study of patients with stroke admitted to the 28 New Zealand acute stroke hospitals (10 in urban areas) recruited between May and October 2018. Data were collected up to 12 months poststroke including treatments in hospital, inpatient rehabilitation, other health service utilization, aged residential care, productivity, and health-related quality of life. Costs in New Zealand dollars were estimated from a societal perspective and assigned to the initial hospital that patients presented to. Unit prices for 2018 were obtained from government and hospital sources. Multivariable regression analyses were conducted when assessing differences between groups. Of 1510 patients (median age 78 years, 48% female), 607 presented to nonurban and 903 to urban hospitals. Mean hospital costs were greater in urban than nonurban hospitals ($13 191 versus $11 635, P =0.002), as were total costs to 12 months ($22 381 versus $17 217, P .001) and quality-adjusted life years to 12 months (0.54 versus 0.46, P .001). Differences in costs and quality-adjusted life years remained between groups after adjustment. Depending on the covariates included, costs per additional quality-adjusted life year in the urban hospitals compared to the nonurban hospitals ranged from $65 038 (unadjusted) to $136 125 (covariates: age, sex, prestroke disability, stroke type, severity, and ethnicity). Better outcomes following initial presentation to urban hospitals were associated with greater costs compared to nonurban hospitals. These findings may inform greater targeted expenditure in some nonurban hospitals to improve access to treatment and optimize outcomes.
Trends in stroke reperfusion treatment and outcomes in New Zealand
Publisher: Wiley
Date: 11-2020
DOI: 10.1111/IMJ.14682
Abstract: Intravenous thrombolysis (IVT) and endovascular thrombectomy (EVT) can help reverse stroke symptoms in selected patients but are both time sensitive interventions. To report current stroke reperfusion rates and quality measures as well as trends over time in New Zealand. Since 2015 New Zealand treatment centres have been mandated to enter prospectively all IVT and EVT patients into a low-cost National Stroke Register. Data were cleaned, and missing data added where possible through contact with in idual hospitals. Main outcomes include treatment delays, vital status at day 7 and complications. In 2018, there were 719 of 7173 (10.0%) patients with ischaemic stroke or stroke unspecified treated with IVT, up from 389 of 5963 (6.5%) patients in 2015 (P < 0.001), with no change in day 7 mortality (P = 0.63) or sICH rate (P = 0.22). Median (interquartile range (IQR)) door-to-needle times decreased from 65 (47-89) min in 2017 to 59 (40-84) min in 2018 (P = 0.022), and patients treated within 60 min increased from 40 to 51% (P < 0.001). In 2018, there were 243 (3.4%) patients treated with EVT up from 134/6859 (1.9%) in 2017 (P < 0.0001), with no change in 7-day mortality (P = 0.39) or intracerebral haemorrhage (sICH) (P = 0.78). There was no significant change in onset-to-needle (P = 0.21), arrival-to-groin (P = 0.28) or onset-to-reperfusion time (P = 0.32). Stroke reperfusion rates in New Zealand are continuously rising with no associated increase in complications. More patients are being treated faster upon hospital arrival but there remains room for further improvement in reducing onset to treatment delays.
Sports-related brain injury in the general population: An epidemiological study
Publisher: Elsevier BV
Date: 11-2014
DOI: 10.1016/J.JSAMS.2014.02.001
Abstract: To determine the incidence, nature and severity of all sports-related brain injuries in the general population. Population-based epidemiological incidence study. Data on all traumatic brain injury events sustained during a sports-related activity were extracted from a dataset of all new traumatic brain injury cases (both fatal and non-fatal), identified over a one-year period in the Hamilton and Waikato districts of New Zealand. Prospective and retrospective case ascertainment methods from multiple sources were used. All age groups and levels of traumatic brain injury severity were included. Details of the registering injuries and recurrent injuries sustained over the subsequent year were obtained through medical/accident records and assessment interviews with participants. Of 1369 incident traumatic brain injury cases, 291 were identified as being sustained during a sports-related activity (21% of all traumatic brain injuries) equating to an incidence rate of 170 per 100,000 of the general population. Recurrent injuries occurred more frequently in adults (11%) than children (5%). Of the sports-related injuries 46% were classified as mild with a high risk of complications. Injuries were most frequently sustained during rugby, cycling and equestrian activities. It was revealed that up to 19% of traumatic brain injuries were not recorded in medical notes. Given the high incidence of new and recurrent traumatic brain injury and the high risk of complications following injury, further sport specific injury prevention strategies are urgently needed to reduce the impact of traumatic brain injury and facilitate safer engagement in sports activities. The high levels of 'missed' traumatic brain injuries, highlights the importance in raising awareness of traumatic brain injury during sports-related activity in the general population.
Cerebral Ischemic Lesions on Diffusion-Weighted Imaging Are Associated With Neurocognitive Decline After Cardiac Surgery
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2008
DOI: 10.1161/STROKEAHA.107.502989
Abstract: Background and Purpose— Improvements in cardiac surgery mortality and morbidity have focused interest on the neurological injury such as stroke and cognitive decline that may accompany an otherwise successful operation. We aimed to investigate (1) the rate of stroke, new ischemic change on MRI, and cognitive impairment after cardiac valve surgery and (2) the controversial relationship between perioperative cerebral ischemia and cognitive decline. Methods— Forty patients (26 men mean [SD] age 62.1 [13.7] years) undergoing intracardiac surgery (7 also with coronary artery bypass grafting) were studied. Neurological, neuropsychological, and MRI examinations were performed 24 hours before surgery and 5 days (MRI and neurology) and 6 weeks (neuropsychology and neurology) after surgery. Cognitive decline from baseline was determined using the Reliable Change Index. Results— Two of 40 (5%) patients had perioperative strokes and 22 of 35 (63%) tested had cognitive decline in at least one measure (range, 1 to 4). Sixteen of 37 participants (43%) with postoperative imaging had new ischemic lesions (range, 1 to 17 lesions) with appearances consistent with cerebral embolization. Cognitive decline was seen in all patients with, and 35% of those without, postoperative ischemic lesions ( P .001), and there was an association between the number of abnormal cognitive tests and ischemic burden ( P .001). Conclusion— We have provided a reliable estimate of the rate of stroke, postoperative ischemia, and cognitive impairment at 6 weeks after cardiac valve surgery. Cognitive impairment is associated with perioperative ischemia and is more severe with greater ischemic load.
Morvan's syndrome associated with voltage-gated K+ channel antibodies
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-02-2000
DOI: 10.1212/WNL.54.3.771
A pilot randomised controlled trial of the management of systolic blood pressure during endovascular thrombectomy for acute ischaemic stroke
Publisher: Wiley
Date: 12-12-2019
DOI: 10.1111/ANAE.14940
Abstract: It is unknown whether systolic blood pressure augmentation during endovascular thrombectomy improves clinical outcomes. This pilot randomised controlled trial aimed to assess the feasibility of differential systolic blood pressure targeting during endovascular thrombectomy procedures for anterior circulation ischaemic stroke. Fifty-one eligible patients fulfilling the national criteria for endovascular thrombectomy were randomly assigned to receive either standard or augmented systolic blood pressure management from the start of anaesthesia to recanalisation of the target vessel. Systolic blood pressure targets for the standard and augmented groups were 130-150 mmHg and 160-180 mmHg, respectively. The study achieved all feasibility targets, including a recruitment rate of 3.5 participants per week and median (IQR [range]) of mean systolic blood pressure separation between groups of 139 (135-143 [115-154]) vs. 167 (150-175 [113-188]) mmHg, p < 0.001. Data completeness was 99%. Independent functional recovery at 90 days (modified Rankin Scale 0, 1 or 2) was achieved in 30 (59%) patients, which is consistent with previously published data. There were no safety concerns with trial procedures. In conclusion, a large randomised controlled efficacy trial of standard vs. augmented systolic blood pressure management during endovascular thrombectomy is feasible.
Identification, risk assessment, and management of patients with atrial fibrillation in a large primary care cohort
Publisher: Elsevier BV
Date: 03-2018
DOI: 10.1016/J.IJCARD.2017.11.045
Abstract: Atrial fibrillation (AF) is associated with increased risk of cardiovascular disease (CVD) complications including stroke. We investigated the assessment and management of cardiovascular risk among patients with AF aged 35-74years, by ethnic group, in a large cohort of people receiving a CVD risk assessment in primary care (PREDICT). PREDICT was linked to national dispensing, hospitalisation and mortality records. AF was present if recorded in PREDICT or during a prior hospitalisation medications were those dispensed ≤6months before or after a PREDICT assessment the CHA 12,739 (2.8%) of 447,020 people aged 35-74years had AF. Māori, the indigenous population of NZ, had the highest proportion of AF, which by age group, was similar to that among Europeans 10years older. 77% were at high stroke risk, of whom 42% received anticoagulation 54% were at high CVD risk, of whom 67% received both lipid- and blood pressure-lowering medication. Per category of predicted risk, stroke risk was overestimated and risk of MACE was underestimated. The burden of AF and risk factors differed by ethnic group thus recommendations to screen for AF above a universal age threshold may introduce inequity in the detection and management of associated risk. The high burden of comorbidities at younger ages among many ethnic groups contributes to the poor performance of available risk assessment tools, further compounding potential inequity.
Increased Large Vessel Occlusive Strokes After the Christchurch March 15, 2019, Terror Attack
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 26-01-2021
Longitudinal patterns of behavior, cognition, and quality of life after mild traumatic brain injury in children: BIONIC study findings
Publisher: Informa UK Limited
Date: 23-04-2019
Potential PINK1 Founder Effect in Polynesia Causing Early‐Onset Parkinson's Disease
Publisher: Wiley
Date: 22-06-2021
DOI: 10.1002/MDS.28665
The Characteristics of Patients With Possible Transient Ischemic Attack and Minor Stroke in the Hunter and Manning Valley Regions, Australia (the INSIST Study)
Publisher: Frontiers Media SA
Date: 15-05-2020
Stroke management: Updated recommendations for treatment along the care continuum
Publisher: Wiley
Date: 05-2012
DOI: 10.1111/J.1445-5994.2012.02774.X
Abstract: The Australian Clinical Guidelines for Stroke Management 2010 represents an update of the Clinical Guidelines for Stroke Rehabilitation and Recovery (2005) and the Clinical Guidelines for Acute Stroke Management (2007). For the first time, they cover the whole spectrum of stroke, from public awareness and prehospital response to stroke unit and stroke management strategies, acute treatment, secondary prevention, rehabilitation and community care. The guidelines also include recommendations on transient ischaemic attack. The most significant changes to previous guideline recommendations include the extension of the stroke thrombolysis window from 3 to 4.5 h and the change from positive to negative recommendations for the use of thigh-length antithrombotic stockings for deep venous thrombosis prevention and the routine use of prolonged positioning for contracture management.
Circuit-Based Rehabilitation Improves Gait Endurance but Not Usual Walking Activity in Chronic Stroke: A Randomized Controlled Trial
Publisher: Elsevier BV
Date: 12-2009
DOI: 10.1016/J.APMR.2009.07.015
Abstract: Mudge S, Barber PA, Stott NS. Circuit-based rehabilitation improves gait endurance but not usual walking activity in chronic stroke: a randomized controlled trial. To determine whether circuit-based rehabilitation would increase the amount and rate that in iduals with stroke walk in their usual environments. Single-blind randomized controlled trial. Rehabilitation clinic. Sixty participants with a residual gait deficit at least 6 months after stroke originally enrolled in the study. Two withdrew in the initial phase, leaving 58 participants (median age, 71.5y range, 39.0-89.0y) who were randomized to the 2 intervention groups. The exercise group had 12 sessions of clinic-based rehabilitation delivered in a circuit class designed to improve walking. The control group received a comparable duration of group social and educational classes. Usual walking performance was assessed using the StepWatch Activity Monitor. Clinical tests were gait speed (timed 10-meter walk) and endurance (six-minute walk test [6MWT]), confidence (Activities-Based Confidence Scale), self-reported mobility (Rivermead Mobility Index [RMI]), and self-reported physical activity (Physical Activity and Disability Scale). Intention-to-treat analysis revealed that the exercise group showed a significantly greater distance for the 6MWT than the control group immediately after the intervention (P=.030) but that this effect was not retained 3 months later. There were no changes in the StepWatch measures of usual walking performance for either group. The exercise and control groups had significantly different gait speed (P=.038) and scores on the RMI (P=.025) at the 3-month follow-up. These differences represented a greater decline in the control group compared with the exercise group for both outcome measures. Circuit-based rehabilitation leads to improvements in gait endurance but does not change the amount or rate of walking performance in usual environments. Clinical gains made by the exercise group were lost 3 months later. Future studies should consider whether rehabilitation needs to occur in usual environments to improve walking performance.
Clinical–Diffusion Mismatch and Benefit From Thrombolysis 3 to 6 Hours After Acute Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2009
DOI: 10.1161/STROKEAHA.109.548073
Abstract: Background and Purpose— The clinical-diffusion mismatch (CDM) model has been proposed as a simpler tool than perfusion-diffusion mismatch (PDM) to select acute ischemic stroke patients for thrombolytic therapy. We hypothesized that in the 3- to 6-hour time window, the effect of tPA was significantly greater in patients with CDM than in patients without CDM. Methods— This is a substudy of EPITHET, a double-blind multi-center study of 100 patients randomized to tPA or placebo 3 to 6 hours after stroke onset. MRI was obtained before treatment, and at 3 to 5 days and 90 days after treatment. Presence of PDM (perfusion deficit/DWI volume .2 and perfusion deficit at least 10 mL DWI volume ) and CDM (NIHSS ≥8 and DWI volume ≤25 mL) was determined for each patient. We assessed lesion growth and neurological improvement (decrease in NIHSS ≥8 points between baseline and 90 days, or a 90-day NIHSS ≤1). Results— 86% of the patients had PDM, but only 41% had CDM. CDM detected PDM with a sensitivity of 46% and a specificity of 86%. We found statistically significant effects of reperfusion on the rate of neurological improvement (OR 9.92, 95% CI 1.91 to 51.64 P .01) and on absolute growth (difference: −59.60 mL, 95% CI −95.40 mL to −23.81 mL P .01). Neither treatment with tPA nor reperfusion had a significantly different impact on lesion growth or clinical course in CDM patients compared to patients without CDM. Conclusions— There was no increased benefit from tPA in patients with CDM. The beneficial effects of reperfusion were similar in patients with and without CDM.
Ischemic diffusion lesion reversal is uncommon and rarely alters perfusion-diffusion mismatch
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 18-08-2010
Association of Reperfusion After Thrombolysis With Clinical Outcome Across the 4.5- to 9-Hours and Wake-up Stroke Time Window
Publisher: American Medical Association (AMA)
Date: 02-2021
Neurochemical balance and inhibition at the subacute stage after stroke
Publisher: American Physiological Society
Date: 05-2020
Abstract: Magnetic resonance spectroscopy indicated higher excitation-inhibition ratios within motor cortex during subacute recovery than age-similar healthy controls. Measures obtained from adaptive threshold hunting paired-pulse transcranial magnetic stimulation indicated greater tonic inhibition in patients compared with controls. Therapeutic approaches that aim to normalize motor cortex inhibition during the subacute stage of recovery should be explored.
Identification of major ischemic change - Diffusion-weighted imaging versus computed tomography
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-1999
DOI: 10.1161/01.STR.30.10.2059
Abstract: Background and Purpose —Thrombolytic therapy is not recommended in patients with CT changes of recent major infarction, which has been defined as reduced attenuation or cerebral edema involving % of the middle cerebral artery territory (European Cooperative Acute Stroke Study [ECASS] criteria). Diffusion-weighted imaging (DWI) is more sensitive than CT in detecting acute ischemia, and the combination of DWI, MR perfusion imaging, and MR angiography provides additional information from a single examination. We sought to determine whether DWI could identify the presence and extent of major ischemia as well as CT in hyperacute stroke patients. Methods —Seventeen suspected hemispheric stroke patients were studied with both CT and DWI within 6 hours of symptom onset. None received thrombolytic therapy. The scans were examined separately by 2 neuroradiologists in a blinded fashion for ischemic change and cerebral edema, graded as normal, %, or % of the MCA territory. Final diagnosis of stroke was determined with the use of standard clinical criteria and T2-weighted imaging at day 90. Results —Sixteen of 17 patients had a final diagnosis of stroke. Acute ischemic changes were seen in all 16 on DWI (100% sensitivity) and in 12 of 16 on CT (75% sensitivity). DWI identified all 6 patients with major ischemia on CT, with excellent agreement between the 2 imaging techniques (κ=0.88). One patient eligible for thrombolysis on the ECASS CT criteria had major ischemia on DWI. Conclusions —DWI is more sensitive than CT in the identification of acute ischemia and can visualize major ischemia more easily than CT.
Combined H-1 MR spectroscopy and diffusion-weighted MRI improves the prediction of stroke outcome
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 22-08-2000
DOI: 10.1212/WNL.55.4.498
Abstract: The prognostic value of the biochemical changes seen with proton MR spectroscopy (1H MRS) in ischemic stroke was examined. Acute diffusion-weighted imaging (DWI) was used to identify regions of ischemia for 1H MRS voxel localization. Nineteen patients had 36 1H MRS studies, 13 patients acutely (mean, 11.1 hours), 10 subacutely (mean, 3.9 days), and 13 at outcome (mean, 82 days). Single-voxel, long-echo, timepoint-resolved spectroscopy was used to obtain lactate, n-acetylaspartate (NAA), choline, and creatine levels from the infarct core. Outcome measures were final infarct volume and clinical assessment scales (Canadian Neurological Scale, Barthel Index, and Rankin Scale). Acute lactate/choline ratio correlated more strongly with clinical outcome scores (r = 0.76 to 0.83 p < 0.01) and final infarct size (r = 0. 96 p < 0.01) than acute DWI lesion volume or acute NAA/choline ratio. Combination of acute lactate/choline ratio with acute DWI lesion volume improved prediction of all outcome scores (R2 = 0.80 to 0.90). The predictive effect of acute lactate/choline ratio was independent of acute DWI lesion volume (p < 0.001). In subacute and chronic infarction, both lactate/choline and NAA/choline ratios continued to correlate with outcome (p < 0.05). At the chronic stage, persistent lactate/choline ratio elevation strongly correlated with outcome measures (r = 0.71 to 0.87). Lactate/choline ratio measured in the acute infarct core by 1H MRS improves the prediction of stroke outcome and provides prognostic information complementary to DWI. Lactate/choline ratio could be used as an additional marker to select patients for acute and chronic therapies.
Priming sensorimotor cortex to enhance task-specific training after subcortical stroke
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.CLINPH.2013.11.020
Abstract: This double-blind sham-controlled crossover study investigated the interactions between primary sensory and motor cortex after stroke and their response to Theta Burst Stimulation (TBS). Thirteen chronic subcortical stroke patients with upper limb impairment performed standardised dexterity training primed with ipsilesional M1 intermittent TBS (iTBSiM1), contralesional M1 continuous TBS (cTBScM1) or sham TBS. The effects on sensorimotor integration, corticomotor excitability, sensation and grip-lift kinetics were examined. After iTBSiM1, improvements in paretic grip-lift performance were accompanied by an immediate facilitation of ipsilesional M1 excitability and a subsequent increase in ipsilesional short latency afferent inhibition (SAI) during training. Precision grip-lift performance improved after cTBScM1 and training, alongside increased ipsilesional M1 excitability with no effect on ipsilesional SAI. There were no effects on sensory performance. Primary motor cortex iTBS not only modulates M1 corticospinal excitability but also increases M1 receptiveness to sensory input. Priming with iTBSiM1 may enhance ipsilesional sensorimotor integration and facilitate better quality sensorimotor training after subcortical stroke.
Automated Measurement of Cerebral Atrophy and Outcome in Endovascular Thrombectomy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2019
DOI: 10.1161/STROKEAHA.119.027120
Abstract: Methods of identifying ischemic stroke patients with a greater probability of poor outcome following endovascular thrombectomy (EVT) might improve shared treatment decision-making between patients, families, and physicians. We used an objective, automated method to measure cerebral atrophy and investigated whether this was associated with outcome in EVT patients. Consecutive EVT patients from a single-center registry were studied. CT brain scans were segmented with a combination of a validated U-Net and Hounsfield unit thresholding. Intracranial cerebrospinal fluid (CSF) volume was used as a marker of cerebral atrophy and calculated as a proportion of total intracranial volume. The primary outcome was functional independence, defined as a 3-month modified Rankin Scale score of 0 to 2. Three-hundred sixty EVT patients were included. Functional independence was achieved in 204 (56.7%) patients. The mean±SD CSF volume was 9.0±4.7% of total intracranial volume. Multivariable regression demonstrated that increasing CSF volume was associated with reduced functional independence (OR=0.65 per 5% increase in CSF volume 95% CI, 0.48–0.89 P =0.007) and higher 3-month modified Rankin Scale scores (common OR, 1.59 per 5% increase in CSF volume 95% CI, 1.05–2.41 P =0.03). Cerebral atrophy determined by automated measurement of intracranial CSF volume is associated with functional outcome in patients undergoing EVT. If validated in future studies, this simple, objective, and automated imaging marker could potentially be incorporated into decision-support tools to improve shared treatment decision-making.
Measuring stroke and transient ischemic attack burden in New Zealand: Protocol for the fifth Auckland Regional Community Stroke Study (ARCOS V)
Publisher: SAGE Publications
Date: 24-10-2019
Abstract: Aim: The goal of this paper is to provide a protocol for conducting a fifth population-based Auckland Regional Community Stroke study (ARCOS V) in New Zealand. Methods and Discussion: In this study, for the first time globally, (1) stroke and TIA burden will be determined using the currently used clinical and tissue-based definition of stroke, in addition to the WHO clinical classifications of stroke used in all previous ARCOS studies, as well as more advanced criteria recently suggested for an “ideal” population-based stroke incidence and outcomes study and (2) age, sex, and ethnic-specific trends in stroke incidence and outcomes will be determined over the last four decades, including changes in the incidence of acute cerebrovascular events over the last decade. Furthermore, information at four time points over a 40-year period will allow the assessment of effects of recent changes such as implementation of the FAST c aign, ambulance pre-notification, and endovascular treatment. This will enable more accurate projections for health service planning and delivery. Conclusion: The methods of this study will provide a foundation for future similar population-based studies in other countries and populations.
Complications of Intravenous Tenecteplase Versus Alteplase for the Treatment of Acute Ischemic Stroke: A Systematic Review and Meta-Analysis
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2023
DOI: 10.1161/STROKEAHA.122.042335
Abstract: Prior systematic reviews have compared the efficacy of intravenous tenecteplase and alteplase in acute ischemic stroke, assigning their relative complications as a secondary objective. The objective of the present study is to determine whether the risk of treatment complications differs between patients treated with either agent. We performed a systematic review including interventional studies and prospective and retrospective, observational studies enrolling adult patients treated with intravenous tenecteplase for ischemic stroke (both comparative and noncomparative with alteplase). We searched MEDLINE, Embase, the Cochrane Library, Web of Science, and the www.ClinicalTrials.gov registry from inception through June 3, 2022. The primary outcome was symptomatic intracranial hemorrhage, and secondary outcomes included any intracranial hemorrhage, angioedema, gastrointestinal hemorrhage, other extracranial hemorrhage, and mortality. We performed random effects meta-analyses where appropriate. Evidence was synthesized as relative risks, comparing risks in patients exposed to tenecteplase versus alteplase and absolute risks in patients treated with tenecteplase. Of 2226 records identified, 25 full-text articles (reporting 26 studies of 7913 patients) were included. Sixteen studies included alteplase as a comparator, and 10 were noncomparative. The relative risk of symptomatic intracranial hemorrhage in patients treated with tenecteplase compared with alteplase in the 16 comparative studies was 0.89 ([95% CI, 0.65–1.23] I 2 =0%). Among patients treated with low dose ( .2 mg/kg 4 studies), medium dose (0.2–0.39 mg/kg 13 studies), and high dose (≥0.4 mg/kg 3 studies) tenecteplase, the RRs of symptomatic intracranial hemorrhage were 0.78 ([95% CI, 0.22–2.82] I 2 =0%), 0.77 ([95% CI, 0.53–1.14] I 2 =0%), and 2.31 ([95% CI, 0.69–7.75] I 2 =40%), respectively. The pooled risk of symptomatic intracranial hemorrhage in tenecteplase-treated patients, including comparative and noncomparative studies, was 0.99% ([95% CI, 0%–3.49%] I 2 =0%, 7 studies), 1.69% ([95% CI, 1.14%–2.32%] I 2 =1%, 23 studies), and 4.19% ([95% CI, 1.92%–7.11%] I 2 =52%, 5 studies) within the low-, medium-, and high-dose groups. The risks of any intracranial hemorrhage, mortality, and other studied outcomes were comparable between the 2 agents. Across medium- and low-dose tiers, the risks of complications were generally comparable between those treated with tenecteplase versus alteplase for acute ischemic stroke.
Diffusion‐ and perfusion‐weighted MRI response to thrombolysis in stroke
Publisher: Wiley
Date: 31-12-2001
DOI: 10.1002/ANA.10067
Abstract: Diffusion- and perfusion-weighted magnetic resonance imaging provides important pathophysiological information in acute brain ischemia. We performed a prospective study in 19 sub-6-hour stroke patients using serial diffusion- and perfusion-weighted imaging before intravenous thrombolysis, with repeat studies, both subacutely and at outcome. For comparison of ischemic lesion evolution and clinical outcome, we used a historical control group of 21 sub-6-hour ischemic stroke patients studied serially with diffusion- and perfusion-weighted imaging. The two groups were well matched for the baseline National Institutes of Health Stroke Scale and magnetic resonance parameters. Perfusion-weighted imaging-diffusion-weighted imaging mismatch was present in 16 of 19 patients treated with tissue plasminogen activator, and 16 of 21 controls. Perfusion-weighted imaging-diffusion-weighted imaging mismatch patients treated with tissue plaminogen activator had higher recanalization rates and enhanced reperfusion at day 3 (81% vs 47% in controls), and a greater proportion of severely hypoperfused acute mismatch tissue not progressing to infarction (82% vs -25% in controls). Despite similar baseline diffusion-weighted imaging lesions, infarct expansion was less in the recombinant tissue plaminogen activator group (14cm(3) vs 56cm(3) in controls). The positive effect of thrombolysis on lesion growth in mismatch patients translated into a greater improvement in baseline to outcome National Institutes of Health Stroke Scale in the group treated with recombinant tissue plaminogen activator, and a significantly larger proportion of patients treated with recombinant tissue plaminogen activator having a clinically meaningful improvement in National Institutes of Health Stroke Scale of > or = 7 points. The natural evolution of acute perfusion-weighted imaging-diffusion-weighted imaging mismatch tissue may be altered by thrombolysis, with improved stroke outcome. This has implications for the use of diffusion- and perfusion-weighted imaging in selecting and monitoring patients for thrombolytic therapy.
Taking charge after stroke: promoting self-directed rehabilitation to improve quality of life – a randomized controlled trial
Publisher: SAGE Publications
Date: 15-11-2011
Abstract: Objective: Few community interventions following stroke enhance activity, participation or quality of life. We tested two novel community interventions designed to promote self-directed rehabilitation following stroke. Design: This was a randomized, controlled parallel group 2×2 trial. Setting: Community. Participants: Maori and Pacific New Zealanders, years old, randomized within three months of a new stroke. Interventions: A DVD of four inspirational stories by Maori and Pacific people with stroke and a ‘Take Charge Session’ – a single structured risk factor and activities of daily living assessment, designed to facilitate self-directed rehabilitation. Main measures: Primary outcomes were Health-related Quality of Life (Physical Component Summary (PCS) and Mental Component Summary (MCS) scores of the Short Form 36 (SF-36)) 12 months from randomization. Secondary outcomes were Barthel Index, Frenchay Activities Index, Carer Strain Index and modified Rankin score. Results: One hundred and seventy-two people were randomized with 139 (80.8%) followed up at 12 months post randomization. The effect of the Take Charge Session on SF-36 PCS at 12 months was 6.0 (95% confidence interval (CI) 2.0 to 10.0) and of the DVD was 0.9 (95% CI −3.1 to 4.9). Participants allocated to the Take Charge Session were less likely to have a modified Rankin score of (odds ratio (OR) 0.42, 95% CI 0.2 to 0.89) and their carers had lower (better) Carer Strain Index scores (−1.5, 95% CI −2.8 to −0.1). Conclusion: A simple, low-cost intervention in the community phase of stroke recovery aiming to promote self-directed rehabilitation improved outcomes.
Effects of alteplase beyond 3 h after stroke in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET): a placebo-controlled randomised trial
Publisher: Elsevier BV
Date: 04-2008
Chronic Kidney Disease and Outcome Following Endovascular Thrombectomy for Acute Ischemic Stroke
Publisher: Elsevier BV
Date: 04-2020
Anticoagulation Therapy in Endovascular Thrombectomy Patients With Large‐Vessel Occlusion Caused by Cardioembolism
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2022
Abstract: In patients with ischemic stroke, cardioembolism, predominantly caused by atrial fibrillation (AF), is a leading preventable cause of large‐vessel occlusion (LVO). Despite proven efficacy, inadequate oral anticoagulant (OAC) therapy continues to be a major problem in patients with AF, mechanical heart valves, and other potential sources of emboli. We aimed to determine rates of cardioembolic LVO, the adequacy of OAC, and the association of OACs with clinical outcomes in patients with LVO treated with endovascular thrombectomy (EVT). Consecutive patients with cardioembolism treated with EVT were included and had pre‐stroke indication for OACs and the adequacy of anticoagulation determined. The primary outcome was 3‐month functional independence (modified Rankin Scale score 0–2). Secondary outcomes included early neurological recovery (reduction in National Institutes of Health Stroke Scale score ≥8 points, or score of 0–1 at 24 hours), symptomatic intracranial hemorrhage, and 3‐month mortality and modified Rankin Scale score. There were 784 patients treated with EVT, of whom 416 (53.1% 231 men mean±SD age, 67.1±15.9) had cardioembolic LVO. Of those with cardioembolism, 221 (53.1%) had prevalent AF, 99 (23.8%) incident AF, 48 (11.5%) mechanical heart valves, 10 (2.4%) left ventricular thrombus, and 38 (9.1%) other cardioembolic causes. A total of 242 patients were identified as having a pre‐stroke indication for OACs, and 67 (27.7%) of these patients were considered adequately anticoagulated at time of LVO. In all 242 patients with cardioembolism with a pre‐stroke indication for OACs, adequate anticoagulation was not associated with EVT outcomes. However, adequate anticoagulation in patients with prevalent AF was associated with lower rates of internal carotid artery occlusion (6.8% versus 18.9% P =0.03) and higher rates of functional independence (odds ratio=1.94 95% CI, 1.02–3.78] P =0.04). Over half of patients treated with EVT were assessed as having a cardioembolic cause. Just over a quarter of patients with an indication for OACs at the time of LVO were adequately anticoagulated. These figures suggest that a substantial number of EVT procedures may have been avoided if more patients had been adequately anticoagulated.
Improved survival after stroke: Is admission to hospital the major explanation? Trend analyses of the Auckland Regional Community Stroke studies
Publisher: S. Karger AG
Date: 16-11-2007
DOI: 10.1159/000097054
Abstract: i Background: /i There is uncertainty regarding the impact of changes in stroke care and natural history of stroke in the community. We examined factors responsible for trends in survival after stroke in a series of population-based studies. i Methods: /i We used statistical models to assess temporal trends in 28-day and 1-year case fatality after first-ever stroke cases registered in 3 stroke incidence studies undertaken in Auckland, New Zealand, over uniform 12-month calendar periods in 1981–1982 (n = 1,030), 1991–1992 (1,305) and 2001–2002 (1,423). Cox proportional hazards regression was used to evaluate the significance of pre-defined ‘patient’, ‘disease’ and ‘service/care’ factors on these trends. i Results: /i Overall, there was a 40% decline in 28-day case fatality after stroke over the study periods, from 32% (95% confidence interval, 29–35%) in 1981–1982 to 23% (21–25%) in 1991–1992 and then 19% (17–21%) in 2002–2003. Similar relative declines were seen in 1-year case fatality. In regression models, the trends were still significant after adjusting for patient and disease factors. However, further adjustment for care factors (higher hospital admission and neuroimaging) explained most of the improvement in survival. i Conclusions: /i These data show significant downwards trends in case fatality after stroke in Auckland over 20 years, which can largely be attributed to improved stroke care associated with increases in hospital admission and brain imaging during the acute phase of the illness.
Reversible cerebral vasoconstriction following carotid endarterectomy
Publisher: Elsevier BV
Date: 12-2011
DOI: 10.1016/J.JOCN.2011.03.018
Abstract: Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by the triad of severe "thunderclap" headaches, neurological symptoms and transient segmental cerebral arterial vasoconstriction. We report a patient with RCVS following carotid endarterectomy and review the literature on RCVS following carotid revascularisation.
Reversible cerebral vasoconstriction in Guillain–Barré syndrome
Publisher: Elsevier BV
Date: 07-2015
DOI: 10.1016/J.JOCN.2014.12.012
Abstract: We present a 51-year-old woman with clinical and neurophysiological evidence of Guillain-Barré syndrome (GBS) who developed a generalised headache and autonomic dysfunction with sinus tachycardia, hypertension, gastrointestinal motility symptoms and urinary retention. MRI/MRA demonstrated cerebral vasoconstriction and a small convexity subarachnoid haemorrhage which resolved after 3 months. Reversible cerebral vasoconstriction syndrome (RCVS) is characterised by headache, focal neurological deficits or seizures, and reversible cerebral vasoconstriction. To our knowledge, this is the first reported case of RCVS complicating autonomic dysfunction in GBS. This case depicts a rare complication of a common condition and also sheds light on the potential mechanism of RCVS. Neurologists should be aware that autonomic dysfunction can lead to RCVS in GBS.
Neurophysiology to guide acute stroke treatment
Publisher: Elsevier BV
Date: 09-2020
Proportional Motor Recovery After Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2017
DOI: 10.1161/STROKEAHA.116.016020
Abstract: Recovery of upper-limb motor impairment after first-ever ischemic stroke is proportional to the degree of initial impairment in patients with a functional corticospinal tract (CST). This study aimed to investigate whether proportional recovery occurs in a more clinically relevant s le including patients with intracerebral hemorrhage and previous stroke. Patients with upper-limb weakness were assessed 3 days and 3 months poststroke with the Fugl–Meyer scale. Transcranial magnetic stimulation was used to test CST function, and patients were dichotomized according to the presence of motor evoked potentials in the paretic wrist extensors. Linear regression modeling of Δ Fugl–Meyer score between 3 days and 3 months was performed, with predictors including initial impairment (66 − baseline Fugl–Meyer score), age, sex, stroke type, previous stroke, comorbidities, and upper-limb therapy dose. One hundred ninety-two patients were recruited, and 157 completed 3-month follow-up. Patients with a functional CST made a proportional recovery of 63% (95% confidence interval, 55%–70%) of initial motor impairment. The recovery of patients without a functional CST was not proportional to initial impairment and was reduced by greater CST damage. Recovery of motor impairment in patients with intact CST is proportional to initial impairment and unaffected by previous stroke, type of stroke, or upper-limb therapy dose. Novel interventions that interact with the neurobiological mechanisms of recovery are needed. The generalizability of proportional recovery is such that patients with intracerebral hemorrhage and previous stroke may usefully be included in interventional rehabilitation trials. URL: www.anzctr.org.au . Unique identifier: ANZCTR12611000755932.
Limitations of current brain imaging modalities in stroke
Publisher: Cambridge University Press
Date: 20-03-2003
Serial study of apparent diffusion coefficient and anisotropy in patients with acute stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-1999
DOI: 10.1161/01.STR.30.11.2382
Abstract: Background and Purpose —We sought to characterize the evolution of apparent diffusion coefficient (ADC) and apparent diffusion anisotropy (ADA) in acute stroke and to evaluate their roles in predicting stroke evolution and outcome. Methods —We studied 26 stroke patients acutely ( hours), subacutely (3 to 5 days), and at outcome (3 months). Ratios of the ADC and ADA within a region of infarction and the normal contralateral region were evaluated and compared with the Canadian Neurological Scale, Barthel Index, and Rankin Scale. Results —Heterogeneity in ADC and ADA evolution was observed not only between patients but also within in idual lesions. Three patterns of ADA evolution were observed: (1) elevated ADA acutely and subacutely (2) elevated ADA acutely and reduced ADA subacutely and (3) reduced ADA acutely and subacutely. At outcome, reduced ADA with elevated ADC was observed generally. We identified 3 phases of diffusion abnormalities: (1) reduced ADC and elevated ADA (2) reduced ADC and reduced ADA and (3) elevated ADC and reduced ADA. The ADA ratios within 12 hours correlated with the acute Canadian Neurological Scale ( r =0.46, P =0.06), subacute Canadian Neurological Scale ( r =0.55, P =0.02), outcome Barthel Index ( r =0.62, P =0.01), and Rankin Scale ( r =−0.77, P .0005) scores. Conclusions —Combined ADC and ADA provide differential patterns of stroke evolution. Early ADA changes reflect cellular alterations in acute ischemia and may provide a potential marker to predict stroke outcome.
A three-item scale for the early prediction of stroke recovery
Publisher: Elsevier BV
Date: 06-2001
DOI: 10.1016/S0140-6736(00)05183-7
Abstract: Accurate assessment of prognosis in the first hours of stroke is desirable for best patient management. We aimed to assess whether the extent of ischaemic brain injury on magnetic reasonance diffusion-weighted imaging (MR DWI) could provide additional prognostic information to clinical factors. In a three-phase study we studied 66 patients from a North American teaching hospital who had: MR DWI within 36 h of stroke onset the National Institutes of Health Stroke Scale (NIHSS) score measured at the time of scanning and the Barthel Index measured no later than 3 months after stroke. We used logistic regression to derive a predictive model for good recovery. This logistic regression model was applied to an independent series of 63 patients from an Australian teaching hospital, and we then developed a three-item scale for the early prediction of stroke recovery. Combined measurements of the NIHSS score (p=0.01), time in hours from stroke onset to MR DWI (p=0.02), and the volume of ischaemic brain tissue on MR DWI (p=0.04) gave the best prediction of stroke recovery. The model was externally validated on the Australian s le with 0.77 sensitivity and 0.88 specificity. Three likelihood levels for stroke recovery-low (0-2), medium (3-4), and high (5-7)-were identified on the three-item scale. The combination of clinical and MR DWI factors provided better prediction of stroke recovery than any factor alone, shortly after admission to hospital. This information was incorporated into a three-item scale for clinical use.
Functional potential in chronic stroke patients depends on corticospinal tract integrity
Publisher: Oxford University Press (OUP)
Date: 21-11-2006
DOI: 10.1093/BRAIN/AWL333
Abstract: Determining whether a person with stroke has reached their full potential for recovery is difficult. While techniques such as transcranial magnetic stimulation (TMS) and MRI have some prognostic value, their role in rehabilitation is undefined. This study used TMS and MRI to determine which factors predict functional potential, defined as an in idual's capacity for further functional improvement at least 6 months following stroke. We studied 21 chronic stroke patients with upper limb impairment. The functional integrity of the corticospinal tracts (CSTs) was assessed using TMS and functional MRI. The presence or absence of motor-evoked responses (MEPs) to TMS in the affected upper limb, and the lateralization of cortical activity during affected hand use were determined. The structural integrity of the CST was assessed using MRI, and diffusion tensor imaging was used to measure the asymmetry in fractional anisotropy (FA) of the internal capsules. A multiple linear regression analysis was performed, to predict both clinical score at inception and change in clinical score for 17 patients who completed a 30 day programme of motor practice with the affected upper limb. The main findings were that in patients with MEPs, meaningful gains were still possible 3 years after stroke, although the capacity for improvement declined with time. In patients without MEPs, functional potential declines with increasing CST disruption, with no meaningful gains possible if FA asymmetry exceeds a value of 0.25. This study is the first to demonstrate the complementary nature of TMS and MRI techniques in predicting functional potential in chronic stroke patients. An algorithm is proposed for the selection of in idualized rehabilitation strategies, based on the prediction of functional potential. These strategies could include neuromodulation using a range of emerging techniques, to prime the motor system for a plastic response to rehabilitation.
Primary prevention of stroke and cardiovascular disease in the community (PREVENTS): Methodology of a health wellness coaching intervention to reduce stroke and cardiovascular disease risk, a randomiz
Publisher: SAGE Publications
Date: 13-09-2017
Abstract: Stroke is a major cause of death and disability worldwide, yet 80% of strokes can be prevented through modifications of risk factors and lifestyle and by medication. While management strategies for primary stroke prevention in high cardiovascular disease risk in iduals are well established, they are underutilized and existing practice of primary stroke prevention are inadequate. Behavioral interventions are emerging as highly promising strategies to improve cardiovascular disease risk factor management. Health Wellness Coaching is an innovative, patient-focused and cost-effective, multidimensional psychological intervention designed to motivate participants to adhere to recommended medication and lifestyle changes and has been shown to improve health and enhance well-being. To determine the effectiveness of Health Wellness Coaching for primary stroke prevention in an ethnically erse s le including Māori, Pacific Island, New Zealand European and Asian participants. A parallel, prospective, randomized, open-treatment, single-blinded end-point trial. Participants include 320 adults with absolute five-year cardiovascular disease risk ≥ 10%, calculated using the PREDICT web-based clinical tool. Randomization will be to Health Wellness Coaching or usual care groups. Participants randomized to Health Wellness Coaching will receive 15 coaching sessions over nine months. A substantial relative risk reduction of five-year cardiovascular disease risk at nine months post-randomization, which is defined as 10% relative risk reduction among those at moderate five-year cardiovascular disease risk (10–15%) and 25% among those at high risk ( %). This clinical trial will determine whether Health Wellness Coaching is an effective intervention for reducing modifiable risk factors, and hence decrease the risk of stroke and cardiovascular disease.
The Influence of Primary Motor Cortex Inhibition on Upper Limb Impairment and Function in Chronic Stroke: A Multimodal Study
Publisher: SAGE Publications
Date: 02-2019
Abstract: Background. Stroke is a leading cause of adult disability owing largely to motor impairment and loss of function. After stroke, there may be abnormalities in γ-aminobutyric acid (GABA)-mediated inhibitory function within primary motor cortex (M1), which may have implications for residual motor impairment and the potential for functional improvements at the chronic stage. Objective. To quantify GABA neurotransmission and concentration within ipsilesional and contralesional M1 and determine if they relate to upper limb impairment and function at the chronic stage of stroke. Methods. Twelve chronic stroke patients and 16 age-similar controls were recruited for the study. Upper limb impairment and function were assessed with the Fugl-Meyer Upper Extremity Scale and Action Research Arm Test. Threshold tracking paired-pulse transcranial magnetic stimulation protocols were used to examine short- and long-interval intracortical inhibition and late cortical disinhibition. Magnetic resonance spectroscopy was used to evaluate GABA concentration. Results. Short-interval intracortical inhibition was similar between patients and controls ( P = .10). Long-interval intracortical inhibition was greater in ipsilesional M1 compared with controls ( P .001). Patients who did not exhibit late cortical disinhibition in ipsilesional M1 were those with greater upper limb impairment and worse function ( P = .002 and P = .017). GABA concentration was lower within ipsilesional ( P = .009) and contralesional ( P = .021) M1 compared with controls, resulting in an elevated excitation-inhibition ratio for patients. Conclusion. These findings indicate that ipsilesional and contralesional M1 GABAergic inhibition are altered in this small cohort of chronic stroke patients. Further study is warranted to determine how M1 inhibitory networks might be targeted to improve motor function.
Pathophysiological topography of acute ischemia by combined diffusion-weighted and perfusion MRI
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-1999
DOI: 10.1161/01.STR.30.10.2043
Abstract: Background and Purpose —Combined echoplanar MRI diffusion-weighted imaging (DWI), perfusion imaging (PI), and magnetic resonance angiography (MRA) can be used to visualize acute brain ischemia and predict lesion evolution and functional outcome. The appearance of a larger lesion by PI than by DWI quantitatively defines a mismatch of potential clinical importance. Qualitative lesion variations exist in the topographic concordance of this mismatch. We examined both the topographic heterogeneity and relative frequency of mismatched patterns in acute stroke using these MRI techniques. Methods —Acute DWI, PI, and MRA studies of 34 prospectively recruited patients with supratentorial ischemic lesions scanned within 24 hours of stroke onset (range 2.5 to 23.3 hours, 12 patients hours) were analyzed. Results —Ischemic lesions were predominantly in the middle cerebral artery (MCA) territory (94%), with DWI lesions most commonly affecting the insular region. Mismatched patterns with PI lesion larger than DWI lesion occurred in 21 patients (62% overall), in all 4 patients imaged within 3 hours, and in 44% of patients imaged after 18 hours. A patient with a large PI but no DWI lesion and severe clinical deficit at 2.5 hours after stroke onset recovered completely. Regional variations in DWI and PI lesion loci were found, inferring site of proximal MCA occlusion, embolic pathogenesis, and regional arterial reperfusion. Conclusions —Analysis of the topographic concordance of PI and DWI lesions in acute stroke reveals regional PI lesions without concomitant DWI lesions, which do not necessarily progress to infarction but may suggest stroke pathogenesis and site of current arterial occlusion. Location of DWI lesions may suggest an earlier site of arterial occlusion and regions of maximal perfusion deficit.
Not all patients with atrial fibrillation- Associated ischemic stroke can be started on anticoagulant therapy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2006
DOI: 10.1161/01.STR.0000217263.55905.89
Abstract: Background and Purpose— Ischemic stroke patients in atrial fibrillation (AF) have a 10% to 20% risk of recurrent stroke. Warfarin reduces this risk by two thirds. However, warfarin is underutilized in this patient group. We performed a prospective study to determine the reasons why warfarin is not started in these patients. Methods— All patients with AF-associated ischemic stroke over a 12-month period were identified. Demographic and other data, including whether warfarin was commenced or recommended at discharge, and if not why not, were recorded. Results— Ninety-three of 412 (23%) ischemic stroke patients had paroxysmal or permanent AF. Of these patients, 17 (18%) died, 48 (52%) were discharged home, and 28 (30%) were discharged to institutional care. Only 13 of 64 (20%) patients with known AF were taking warfarin at stroke onset. Warfarin was started (or recommended) in 35 of 76 (46%) survivors. Of those not commenced on warfarin, 32 (78%) were dependent ( P .001) and 23 (56%) were discharged to institutional care ( P .001). Warfarin was not started because of severe disability and frailty in 13 (32%), risk of falls in 12 (30%), and limited life expectancy in 4 (10%). Conclusions— In this cohort of patients with AF, warfarin was primarily underutilized before stroke onset, and it was too late to use anticoagulation, in approximately half, once a stroke had occurred. The decision to start or continue anticoagulation requires clinical judgment and should be made on a case by case basis after a complete risk benefit assessment.
Urban versus Non-Urban Hospital Location Impacts on Stroke Outcomes
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2021
DOI: 10.1161/STR.52.SUPPL_1.29
Abstract: Introduction: Stroke care provision differs between urban and provincial hospitals predominantly due to economy of scale, which is correlated with resources available and degree of specialisation. We assessed the impact of urban versus non-urban hospital location on stroke outcomes. Methods: REGIONS Care is a New Zealand (NZ) nationwide prospective observational study that included consecutively admitted stroke patients involving all NZ stroke hospitals between 1 May and 31 October 2018. Patients were followed-up at 3, 6, and 12 months. The primary outcome was favourable modified Rankin Score of 0-2. Results were adjusted for age, stroke severity, pre-morbid level of independence and other potential confounders using multivariate logistic regression. Results: Of the 2,379 patients (mean age (SD), 75 (13.7)), 1,963 (82.6%) had ischaemic strokes and 291 (12.3%) haemorrhagic strokes. The odds of achieving a favourable outcome at 3 and 6 months was significantly lower for patients treated in non-urban compared to urban hospitals: aOR 0.72 (95%CI:0.56-0.93 p=0.012) and aOR 0.71 (95%CI:0.52-0.96 p=0.028), respectively. At 12-months this difference was less pronounced (aOR 0.77, 95%CI:0.57-1.04 p=0.089). Similarly, death was significantly more likely at 3 and 6 months, and borderline statistically significant at 12 months: aOR 1.64, 95%CI:1.30-2.29, p=0.001 1.54, 95%CI:1.12-2.11, p=0.008 and 1.36, 95%CI:0.99-1.87, p=0.06, respectively. Stroke recurrence was similar between urban and non-urban settings at 3 and 6 months, but more likely in the non-urban setting at 12 months (aOR 1.94, 95%CI:1.14-3.29, p=0.014. In the non-urban setting, eligible patients were less likely to receive reperfusion therapy (aOR 0.5, 95%CI:0.28-0.91, p=0.023) acute stroke unit care was less consistently accessed (aOR 0.58, 95%CI:0.48-0.70, p .001) and appropriate secondary preventive therapy was less frequently prescribed (aOR 0.50, 95%CI:0.28-0.91, p=0.023). Conclusion: This first comprehensive prospective NZ nationwide stroke study showed significant differences in stroke outcomes and access to key acute stroke interventions between urban and non-urban hospitals. This inequity requires urgent intervention from health system funders and providers.
Rapid Assessment of Perfusion–Diffusion Mismatch
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2008
DOI: 10.1161/STROKEAHA.107.490524
Abstract: Background and Purpose— For MR perfusion–diffusion (PWI-DWI) mismatch to become routine in thrombolysis patient selection, rapid and reliable assessment tools are required. We examined interrater variability in PWI/DWI volume measurements and developed a rapid assessment tool based on the Alberta Stroke Program Early CT Scores (ASPECTS) system. Methods— DWI and PWI were performed in 35 patients with stroke hours after symptom onset. DWI lesion and PWI (time to peak) volumes were measured with planimetric techniques by 4 raters and the 95% limits of agreement calculated. ASPECT scores were assessed separately by 4 investigators (2 experienced and 2 inexperienced) for DWI (MR DWI scores) and PWI (MR time to peak scores). MR mismatch scores were calculated as MR DWI-MR time to peak scores. Results— Interobserver variability was much greater for PWI (95% limit of agreement=±72.3 mL) than for DWI (95% limit of agreement=±12.6 mL). A semiautomated PWI volume (time to peak+2 s) was therefore used to calculate mismatch volume. MR mismatch scores ≥2 predicted 20% PWI-DWI mismatch by volume with mean 78% sensitivity (range, 72% to 84%) and 88% specificity (range, 83% to 90%). There was excellent agreement on mismatch classification using MR mismatch scores between experienced raters (weighted kappa scores of 0.94) with agreement in 34 of 35 cases. Agreement was less consistent between inexperienced raters (weighted kappa=0.49, 28 of 35 cases). Conclusions— Variability in planimetric mismatch measurements arises primarily from differences in PWI volume assessment. High specificity and interrater reliability may make MR mismatch scores an ideal rapid screening tool for potential thrombolysis patients.
Reperfusion after 4·5 Hours Reduces Infarct Growth and Improves Clinical Outcomes
Publisher: SAGE Publications
Date: 21-11-2013
DOI: 10.1111/IJS.12209
Abstract: The currently proven time window for thrombolysis in ischemic stroke is 4·5 h. Beyond this, the risks and benefits of thrombolysis are uncertain. To determine whether thrombolysis and reperfusion were beneficial after 4·5 h, we examined clinical and radiological outcomes in patients treated with tissue plasminogen activator or placebo within 4·5–6 h, using data from the Echoplanar Imaging Thrombolytic Evaluation Trial. In the Echoplanar Imaging Thrombolytic Evaluation Trial, ischemic stroke patients presenting three to six-hours after stroke onset were randomized to tissue plasminogen activator or placebo, without knowledge of magnetic resonance imaging results. This analysis was restricted to patients treated between 4·5 and 6 h. The effect of tissue plasminogen activator and reperfusion on infarct growth between baseline diffusion-weighted imaging and day 90 T2 imaging was assessed, along with good neurological outcome (⩾8 point reduction or reaching 0–1 at 90 days on National Institutes of Health Stroke Scale) and functional outcome (modified Rankin scale). The effect of tissue plasminogen activator on reperfusion was also analyzed. Sixty-nine patients were treated 4·5–6 h after onset, and infarct growth was assessed in 63. Tissue plasminogen activator was associated with lower relative growth (94% vs. 168%, P = 0·03) and a trend to lower absolute growth (−0·17 ml versus 9·6 ml, P = 0·07). Reperfusion was increased in the tissue plasminogen activator group (58% versus 25%, P = 0·03) and was associated with increased rates of good neurological (86% versus 28% P 0·001) and functional (modified Rankin scale 0–2 73% versus 34%, P = 0·01) outcomes. Reperfusion was strongly associated with lower relative (80% versus 189%, P 0·001) and absolute (−2·5 ml versus 40 ml, P 0·001) infarct growth. Thrombolysis 4·5–6 h after stroke onset reduced infarct growth and increased the rate of reperfusion, which was associated with good neurological and functional outcome.
Bilateral uraemic optic neuritis complicating acute nephrocalcinosis
Publisher: Oxford University Press (OUP)
Date: 17-06-2006
DOI: 10.1093/NDT/GFL321
Imaging in acute ischaemic stroke: pearls and pitfalls
Publisher: BMJ
Date: 25-07-2017
DOI: 10.1136/PRACTNEUROL-2016-001569
Abstract: Prompt and accurate diagnosis is the foundation of acute ischaemic stroke care. Multiple positive endovascular thrombectomy trials in ischaemic stroke patients with large vessel occlusions have further emphasised this but also added complexity to treatment decisions. CT angiography is now routine for patients who present with an acute stroke syndrome around the world. Members of the neurology and stroke teams (rather than radiologists) are often the first doctors to lay eyes on the CT images and are best equipped to integrate the clinical picture with the imaging findings. A sound understanding of acute stroke imaging is therefore essential for clinicians who work with acute stroke patients. This review describes some pearls we have gleaned from our own experience in acute stroke imaging as well as some potential follies to be avoided.
A Multicenter, Randomized, Controlled Study to Investigate Extending the Time for Thrombolysis in Emergency Neurological Deficits with Intra-Arterial Therapy (EXTEND-IA)
Publisher: SAGE Publications
Date: 10-11-2013
DOI: 10.1111/IJS.12206
Abstract: Thrombolysis with tissue plasminogen activator is proven to reduce disability when given within 4.5 h of ischemic stroke onset. However, tissue plasminogen activator only succeeds in recanalizing large vessel arterial occlusion in a minority of patients. We hypothesized that anterior circulation ischemic stroke patients, selected with ‘dual target’ vessel occlusion and evidence of salvageable brain using computed tomography or magnetic resonance imaging ‘mismatch’ within 4.5 h of onset, would have improved reperfusion and early neurological improvement when treated with intra-arterial clot retrieval after intravenous tissue plasminogen activator compared with intravenous tissue plasminogen activator alone. EXTEND-IA is an investigator-initiated, phase II, multicenter prospective, randomized, open-label, blinded-endpoint study. Ischemic stroke patients receiving standard 0.9 mg/kg intravenous tissue plasminogen activator within 4.5 h of stroke onset who have good prestroke functional status (modified Rankin Scale , no upper age limit) will undergo multimodal computed tomography or magnetic resonance imaging. Patients who also meet dual target imaging criteria: vessel occlusion (internal carotid or middle cerebral artery) and mismatch (perfusion lesion: ischemic core mismatch ratio .2, absolute mismatch ml, ischemic core volume ml) will be randomized to either clot retrieval with the Solitaire FR device after full dose intravenous tissue plasminogen activator, or tissue plasminogen activator alone. The coprimary outcome measure will be reperfusion at 24 h and favorable clinical response (reduction in National Institutes of Health Stroke Scale by ≥8 points or reaching 0–1) at day 3. Secondary outcomes include modified Rankin Scale at day 90, death, and symptomatic intracranial hemorrhage.
Biomarker-based patient selection improves stroke rehabilitation trial efficiency
Publisher: Cold Spring Harbor Laboratory
Date: 02-11-2018
DOI: 10.1101/459776
Abstract: Inter-subject variability complicates trials of novel stroke rehabilitation therapies, particularly in the sub-acute phase after stroke. We tested whether selecting patients using motor evoked potential (MEP) status, a physiological biomarker of motor system function, could improve trial efficiency. A retrospective analysis of data from 207 patients (103 women, mean (SD) 70.6 (15.1) years) was used to estimate s le sizes and recruitment rates required to detect a 7-point difference between hypothetical control and treatment groups in upper-limb Fugl-Meyer and Action Research Arm Test scores at 90 days post-stroke. Analyses were carried out for the full s le and for subsets defined by motor evoked potential (MEP) status. Selecting patients according to MEP status reduced the required s le size by 75% compared to an unselected s le. The estimated time needed to recruit the required s le was also reduced by 72% for patients with MEPs, and was increased by 2-3-fold for patients without MEPs. Using biomarkers to select patients can improve stroke rehabilitation trial efficiency by reducing the s le size and recruitment time needed to detect a clinically meaningful effect of the tested intervention.
Ethnic disparities in incidence of stroke subtypes: Auckland Regional Community Stroke Study, 2002–2003
Publisher: Elsevier BV
Date: 02-2006
Contralesional Hemisphere Control of the Proximal Paretic Upper Limb following Stroke
Publisher: Oxford University Press (OUP)
Date: 12-2011
Community Knowledge and Awareness of Stroke in New Zealand
Publisher: Elsevier BV
Date: 03-2020
DOI: 10.1016/J.JSTROKECEREBROVASDIS.2019.104589
Abstract: Community knowledge and stroke awareness is crucial for primary prevention of stroke and timely access to stroke treatments including acute reperfusion therapies. We conducted a national telephone survey to quantify the level of community stroke awareness. A random s le of 400 adults in New Zealand (NZ), stratified by the 4 main ethnic groups, was surveyed. Eligible participants answered stroke awareness questions using both unprompted (open-ended) and prompted questions (using a list). Proportional odds logistic regression models were used to identify factors associated with stroke awareness. Only 1.5% of participants named stroke as a major cause of death. The stroke signs and symptoms most frequently identified from a list were sudden speech difficulty (94%) and sudden 1-sided weakness (92%). Without prompting, 78% of participants correctly identified at least 1 risk factor, 62% identified at least 2, and 35% identified 3 or more. When prompted with the list, scores increased 10-fold compared with unprompted responses. Ethnic disparities were observed, with Pacific peoples having the lowest level of awareness among the 4 ethnic groups. Higher education level, higher income, and personal experience of stroke were predictive of greater awareness (P ≤ .05). Stroke was not recognized as a major cause of death. Although identification of stroke risk factors was high with prompting, awareness was low without prompting, particularly among those with lower education and income. Nationwide, culturally tailored public awareness c aigns are necessary to improve knowledge of stroke risk factors, recognition of stroke in the community and appropriate actions to take in cases of suspected stroke.
The benefits of intravenous thrombolysis relate to the site of baseline arterial occlusion in the echoplanar imaging thrombolytic evaluation trial (EPITHET)
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2010
DOI: 10.1161/STROKEAHA.109.562827
Abstract: Background and Purpose— In ischemic stroke, the site of arterial obstruction has been shown to influence recanalization and clinical outcomes. However, this has not been studied in randomized controlled trials, nor has the impact of arterial obstruction site on reperfusion and infarct growth been assessed. We studied the influence of site and degree of arterial obstruction patients enrolled in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). Methods— EPITHET was a prospective, randomized, placebo-controlled trial of intravenous tissue plasminogen activator (tPA) in the 3- to 6-hour time window. Arterial obstruction site and degree were rated on magnetic resonance angiography blinded to treatment allocation and outcomes. Results— In 101 EPITHET patients, 87 had adequate quality magnetic resonance angiography, of whom 54 had baseline arterial obstruction. Infarct growth attenuation was greater in those with tPA treatment compared to placebo among patients with middle cerebral artery (MCA) obstruction ( P =0.037). The treatment benefit of tPA over placebo in attenuating infarct growth was greater for MCA than internal carotid artery (ICA) obstruction ( P =0.060). With tPA treatment, good clinical outcome was more likely with MCA than with ICA obstruction ( P =0.005). Most patients with ICA obstruction did not achieve good clinical outcome, whether treated with tPA (100%) or placebo (77%). The study was underpowered to prove any treatment benefit of tPA among patients with any or severe degree of arterial obstruction. Conclusions— Arterial obstruction site strongly predicts outcomes. ICA obstruction carries a uniformly poor prognosis, whereas good outcomes with MCA obstruction are associated with tPA therapy.
Spice, pot, and stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 18-08-2014
Perfusion Thresholds in Acute Stroke Thrombolysis
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2003
DOI: 10.1161/01.STR.0000086529.83878.A2
Abstract: Background and Purpose— Perfusion-weighted MRI has been shown to be useful in the early identification of cerebral tissue at risk of infarction during acute ischemia. Identification of threshold perfusion measures that predict infarction may assist in the selection of patients for thrombolysis. Methods— Mean transit time (MTT), regional cerebral blood flow (rCBF), and regional cerebral blood volume (rCBV) maps were generated in 35 acute stroke patients (17 treated with tissue plasminogen activator and 18 control patients) imaged within 6 hours from symptom onset. Day 90 outcome infarcts (T2-weighted MRI) were superimposed on acute MTT, rCBF, and rCBV maps. Perfusion-weighted MRI measures were then calculated for 2 regions: infarcted and salvaged tissue. Results— MTT was prolonged by 22% in infarcted regions relative to salvaged tissue ( P .001). rCBF was 10% lower in infarcted tissue than in salvaged regions ( P .01). rCBV did not differ significantly between infarcted and salvaged regions. When reperfusion occurred, tissue with more severely prolonged MTT was salvaged from infarction relative to patients with persistent hypoperfusion ( P .05). In contrast, rCBF in salvaged regions did not differ between patients with and without reperfusion. In reperfused patients, an inverse correlation ( R =0.93, P .001) was found between time of initial MRI scan and MTT delay in salvaged tissue. Conclusions— Both increases in MTT and decreases in rCBF predict infarction. Differences in MTT also predict salvage in more severely hypoperfused tissue after reperfusion, suggesting that it is the most clinically useful quantitative perfusion measure. Perfusion thresholds for infarction need to be assessed in the context of symptom duration.
Limbic encephalitis - a review
Publisher: Elsevier BV
Date: 09-2008
DOI: 10.1016/J.JOCN.2007.12.003
Abstract: The clinical features of limbic encephalitis are erse and early diagnosis of the disorder is frequently difficult. Four patients with limbic encephalitis are described. An antineuronal antibody was identified in three of these patients. Antibodies directed against voltage-gated potassium channels, the N-methyl-D-aspartate receptor and an unidentified neuropil antigen were each found in one patient. The fourth patient had multifocal paraneoplastic encephalitis associated with small cell lung cancer. The clinical and imaging findings associated with these antibodies and the other antineuronal antibodies described in patients with limbic encephalitis are reviewed. An approach to the diagnosis and management of limbic encephalitis is presented.
Bilateral priming accelerates recovery of upper limb function after stroke: A randomized controlled trial
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2013
DOI: 10.1161/STROKEAHA.113.003537
Abstract: The ability to live independently after stroke depends on the recovery of upper limb function. We hypothesized that bilateral priming with active–passive movements before upper limb physiotherapy would promote rebalancing of corticomotor excitability and would accelerate upper limb recovery at the subacute stage. A single-center randomized controlled trial of bilateral priming was conducted with 57 patients randomized at the subacute stage after first-ever ischemic stroke. The PRIMED group made device-assisted mirror symmetrical bimanual movements before upper limb physiotherapy, every weekday for 4 weeks. The CONTROL group was given intermittent cutaneous electric stimulation of the paretic forearm before physiotherapy. Assessments were made at baseline, 6, 12, and 26 weeks. The primary end point was the proportion of patients who reached their plateau for upper limb function at 12 weeks, measured with the Action Research Arm Test. Odds ratios indicated that PRIMED participants were 3× more likely than controls to reach their recovery plateau by 12 weeks. Intention-to-treat and per-protocol analyses showed a greater proportion of PRIMED participants achieved their plateau by 12 weeks (intention to treat, χ 2 =4.25 P =0.039 and per protocol, χ 2 =3.99 P =0.046). ANOVA of per-protocol data showed PRIMED participants had greater rebalancing of corticomotor excitability than controls at 12 and 26 weeks and interhemispheric inhibition at 26 weeks (all P .05). Bilateral priming accelerated recovery of upper limb function in the initial weeks after stroke. URL: www.anzctr.org.au . Unique identifier: ANZCTR1260900046822.
Protocol for the MAnagement of Systolic blood pressure during Thrombectomy by Endovascular Route for acute ischemic STROKE randomized clinical trial: The MASTERSTROKE trial
Publisher: SAGE Publications
Date: 22-11-2021
DOI: 10.1177/17474930211059029
Abstract: Australian New Zealand Clinical Trials Registry: ACTRN12619001274167p Cerebral blood flow is blood pressure-dependent when cerebral autoregulation is impaired. Cerebral ischemia and anesthetic drugs impair cerebral autoregulation. In ischemic stroke patients treated with endovascular thrombectomy, induced hypertension is a plausible intervention to increase blood flow in the ischemic penumbra until reperfusion is achieved. This could potentially reduce final infarct size and improve functional recovery. To test if patients with large vessel occlusion stroke treated with endovascular thrombectomy will benefit from induced hypertension. Prospective, randomized, parallel group, open label, multicenter clinical trial with blinded assessment of outcomes. Patients with anterior circulation stroke treated with endovascular thrombectomy with general anesthesia within 6 h of symptom onset, and patients with ‘wake up’ stroke or presenting within 6 to 24 h with potentially salvageable tissue on computed tomography perfusion scanning, are included. Participants are randomized to a systolic blood pressure target of 140 mmHg or 170 mmHg from procedure initiation until recanalization. Methods to maintain the blood pressure are at the discretion of the procedural anesthesiologist. The primary efficacy outcome is improvement in disability measured by modified Rankin Scale score at 90 days. The primary safety outcome is all-cause mortality at 90 days. The Mann-Whitney U test will be used to test the ordinal shift in the seven-category modified Rankin Scale score. All-cause mortality will be estimated using the Kaplan-Meier method and compared using a log-rank test.
The Combat Myth and the Gospel's Apocalypse in the Harry Potter Series: Subversion of a Supposed Existential Given
Publisher: Project MUSE
Date: 2012
Reader Response: Prehospital Telestroke vs Paramedic Scores to Accurately Identify Stroke Reperfusion Candidates: A Cluster Randomized Controlled Trial
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 18-04-2023
Absolute cardiovascular risk and GP decision making in TIA and minor stroke
Publisher: Oxford University Press (OUP)
Date: 10-09-2014
Stroke Patients Develop Antibodies That React With Components of
N
-Methyl-
d
-Aspartate Receptor Subunit 1 in Proportion to Lesion Si
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2013
DOI: 10.1161/STROKEAHA.113.001235
Abstract: Antibodies against neuronal antigens develop in patients after stroke and some may serve as biomarkers of neuronal injury. We aimed to determine whether antibodies against subunit 1 (GluN1) of the N -methyl- d -aspartate receptor also develop after stroke and if so, whether they correlate with stroke characteristics. Forty-eight patients with ischemic stroke and 96 healthy controls were tested for the presence of serum antibodies targeting GluN1. Testing was conducted using 20-kDa recombinant GluN1-S2 peptide (by ELISA and Western blotting) and on rat brain tissue (by Western blotting and immunohistochemistry). Clinical examinations and computed tomographic brain scans were performed to assess clinical state and infarct size and location. Of the 48 patients with ischemic stroke, 21 (44%) had antibodies that reacted with the recombinant GluN1-S2. There was no evidence of antibody binding to intact GluN1 in brain tissue. Western blot appearances suggested reactivity with GluN1 degradation products. Patients with anti–GluN1-S2 antibodies were more likely to have higher National Institutes of Health Stroke Scale scores, larger infarcts, and more frequent cortical involvement. Of the 96 controls, only 3 (3%), all aged years, had antibodies that reacted with GluN1-S2 at low levels. Antibodies that bind recombinant GluN1-S2 peptides (but not the intact GluN1 protein) develop transiently in patients after stroke in proportion to infarct size, suggesting that these antibodies are raised secondarily to neuronal damage. The anti–GluN1-S2 antibodies may provide useful information about the presence and severity of cerebral infarction. This will require confirmation in larger studies.
Brain And Infarct Temperature Changes With Active Conductive Head Cooling: A Magnetic Resonance Spectroscopy Imaging Study
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2022
DOI: 10.1161/STR.53.SUPPL_1.TP236
Abstract: Background and Purpose: Active conductive head cooling (HC) is a simple and non-invasive intervention that may potentially slow infarct growth in patients with stroke. Using magnetic resonance spectroscopy imaging (MRSI), we investigated the effect of HC on brain and systemic temperatures. Methods: A cooling cap (WElkins Temperature Regulation System, 2nd Gen) was used to administer HC for 80 minutes to healthy volunteers and patients at least 6 months following a large vessel occlusion stroke. Serial MRSI scans were obtained before and during HC. Brain temperature was estimated using the Metabolite Imaging and Data Analysis System software package, which allows voxel-level temperature calculations using the chemical shift difference between metabolite (N-acetylaspartate, creatine, choline) and water resonances. Rectal temperature, the 11-point Numerical Pain Rating Scale score, heart rate, and blood pressure were measured. The primary outcome was the mean difference in brain temperature before and after HC. Results: Eleven participants (6 healthy volunteers, and 5 post-stroke) had a total of 66 MRSI scans performed over 80±5 minutes of HC. An average absolute temperature of -1.3±0.5°C was delivered via the cooling cap to the scalp of the participants. Following HC, significant reductions in brain temperature (ΔT = -0.9±0.7°C, P =0.002), and to a lesser extent, rectal temperature (ΔT = -0.3±0.1°C, P =0.03) were observed. Linear regression analysis of all 66 MRSI scans showed a brain temperature-by-time gradient of -0.53°C per hour ( P =0.001). In the stroke patients, the temperature-by-time gradient within the infarct was -0.60°C per hour ( P =0.01). HC was well-tolerated, heart rate and blood pressure remained stable, the median (IQR) Numerical Pain Rating Scale score was 2.5 (1-3) at 80 minutes, and none developed shivering. Conclusions: HC was well-tolerated and resulted in potentially clinically meaningful reductions in brain and infarct temperature, with only slight reduction in systemic temperature. Future research should investigate the feasibility of HC as a potential neuroprotective strategy in patients being considered for acute stroke therapies such as mechanical thrombectomy.
Active conductive head cooling of normal and infarcted brain: A magnetic resonance spectroscopy imaging study
Publisher: SAGE Publications
Date: 16-06-2022
DOI: 10.1177/0271678X221107988
Abstract: Active conductive head cooling is a simple and non-invasive intervention that may slow infarct growth in ischemic stroke. We investigated the effect of active conductive head cooling on brain temperature using whole brain echo-planar spectroscopic imaging. A cooling cap (WElkins Temperature Regulation System, 2nd Gen) was used to administer cooling for 80 minutes to healthy volunteers and chronic stroke patients. Whole brain echo-planar spectroscopic imaging scans were obtained before and after cooling. Brain temperature was estimated using the Metabolite Imaging and Data Analysis System software package, which allows voxel-level temperature calculations using the chemical shift difference between metabolite (N-acetylaspartate, creatine, choline) and water resonances. Eleven participants (six healthy volunteers, five post-stroke) underwent 80 ± 5 minutes of cooling. The average temperature of the coolant was 1.3 ± 0.5°C below zero. Significant reductions in brain temperature (ΔT = –0.9 ± 0.7°C, P = 0.002), and to a lesser extent, rectal temperature (ΔT = –0.3 ± 0.1°C, P = 0.03) were observed. Exploratory analysis showed that the occipital lobes had the greatest reduction in temperature (ΔT = –1.5 ± 1.2°C, P = 0.002). Regions of infarction had similar temperature reductions to the contralateral normal brain. Future research could investigate the feasibility of head cooling as a potential neuroprotective strategy in patients being considered for acute stroke therapies.
Failure of collateral blood flow is associated with infarct growth in ischemic stroke
Publisher: SAGE Publications
Date: 08-05-2013
Abstract: Changes in collateral blood flow, which sustains brain viability distal to arterial occlusion, may impact infarct evolution but have not previously been demonstrated in humans. We correlated leptomeningeal collateral flow, assessed using novel perfusion magnetic resonance imaging (MRI) processing at baseline and 3 to 5 days, with simultaneous assessment of perfusion parameters. Perfusion raw data were averaged across three consecutive slices to increase leptomeningeal collateral vessel continuity after subtraction of baseline signal analogous to digital subtraction angiography. Changes in collateral quality, Tmax hypoperfusion severity, and infarct growth were assessed between baseline and days 3 to 5 perfusion-diffusion MRI. Acute MRI was analysed for 88 patients imaged 3 to 6 hours after ischemic stroke onset. Better collateral flow at baseline was associated with larger perfusion-diffusion mismatch (Spearman's Rho 0.51, P 0.001) and smaller baseline diffusion lesion volume (Rho − 0.70, P 0.001). In 30 patients without reperfusion at day 3 to 5, deterioration in collateral quality between baseline and subacute imaging was strongly associated with absolute ( P = 0.02) and relative ( P 0.001) infarct growth. The deterioration in collateral grade correlated with increased mean Tmax hypoperfusion severity (Rho − 0.68, P 0.001). Deterioration in Tmax hypoperfusion severity was also significantly associated with absolute ( P = 0.003) and relative ( P = 0.002) infarct growth. Collateral flow is dynamic and failure is associated with infarct growth.
EPITHET—where next? – Authors' reply
Publisher: Elsevier BV
Date: 07-2008
Stroke Awareness and Knowledge in an Urban New Zealand Population
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.JSTROKECEREBROVASDIS.2015.01.003
Abstract: Stroke is the third most common cause of death and a major cause of chronic disability in New Zealand. Linked to risk factors that develop across the life-course, stroke is considered to be largely preventable. This study assessed the awareness of stroke risk, symptoms, detection, and prevention behaviors in an urban New Zealand population. Demographics, stroke risk factors awareness, symptoms, responsiveness, and prevention behaviors were evaluated using a structured oral questionnaire. Binomial logistic regression analyses were used to identify predictors of stroke literacy. Although personal experience of stroke increased awareness of symptoms and their likeliness to indicate the need for urgent medical attention, only 42.7% of the respondents (n = 850) identified stroke as involving both blood and the brain. Educational attainment at or above a trade certificate, apprenticeship, or diploma increased the awareness of stroke symptoms compared with those with no formal educational attainment. Pacific Island respondents were less likely than New Zealand Europeans to identify a number of stroke risk factors. Māori, Pacific Island, and Asian respondents were less likely to identify symptoms of stroke and indicate the need for urgent medical attention. The variability in stroke awareness and knowledge may suggest the need to enhance stroke-related health literacy that facilitates understanding of risk and of factors that reduce morbidity and mortality after stroke in people of Māori and Pacific Island descent and in those with lower educational attainment or socioeconomic status. It is therefore important that stroke awareness c aigns include tailored components for target audiences.
Bypass of Primary Stroke Centers Compared With Secondary Transfer for Endovascular Thrombectomy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2022
Abstract: Our stroke network operates a hybrid organizational structure, with patients with potential large‐vessel occlusion taken to the local primary stroke center (PSC) during office hours, and directly bypassed to the endovascular thrombectomy–capable stroke center (EVT‐SC) after hours. We aimed to compare the 2 methods of transfer. Consecutive patients with anterior large‐vessel occlusion treated with EVT between August 2017 and February 2021 were identified. Patients who had EVT puncture within 6 hours of last known normal were included for analysis. Patients were grouped into method of presentation: direct bypass to EVT‐SC (“EVT‐SC direct”) or taken to local PSC with secondary transfer to EVT‐SC (“PSC‐transfer”). The primary outcome was 3‐month functional independence (modified Rankin scale score 0–2). Secondary outcomes included mortality at 7 days and at 3 months. A total of 259 patients (109 women mean±SD age, 66.8±15.2 years) were included there were 91 (35.1%) EVT‐SC direct and 168 (64.9%) PSC‐transfer patients. The EVT‐SC direct patients had shorter median times from last known normal to thrombolysis (120 versus 147 minutes P =0.004) and puncture (190 versus 230 minutes P .001). Multivariable logistic regression analysis found that EVT‐SC direct patients had greater 3‐month functional independence (odds ratio [OR], 2.04 [95% CI, 1.12–3.73] P =0.02) and lower 3‐month mortality (OR, 0.33 [95% CI, 0.12–0.91] P =0.03). For every 100 patients directly bypassed to EVT‐SC, there were 14 more patients functionally independent and 9 fewer who had died, at 3 months. In this comparison of 2 organizational paradigms in patients with a PSC as the closest stroke center, direct bypass to EVT‐SC resulted in significantly better process times and clinical outcomes compared with secondary transfers from PSCs.
Geographic Disparities in Stroke Outcomes and Service Access
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 26-07-2022
DOI: 10.1212/WNL.0000000000200526
Abstract: International evidence shows that patients treated at nonurban hospitals experience poorer access to key stroke interventions. Evidence for whether this results in poorer outcomes is conflicting and generally based on administrative or voluntary registry data. The aim of this study was to use prospective high-quality comprehensive nationwide patient-level data to investigate the association between hospital geography and outcomes of patients with stroke and access to best-practice stroke care in New Zealand. This is a prospective, multicenter, nationally representative observational study involving all 28 New Zealand acute stroke hospitals (18 nonurban) and affiliated rehabilitation and community services. Consecutive adults admitted to the hospital with acute stroke between May 1 and October 31, 2018, were captured. Outcomes included functional outcome (modified Rankin Scale [mRS] score shift analysis), functional independence (mRS score 0–2), quality of life (EuroQol 5-dimension, 3-level health-related quality of life questionnaire), stroke/vascular events, and death at 3, 6, and 12 months and proportion accessing thrombolysis, thrombectomy, stroke units, key investigations, secondary prevention, and inpatient/community rehabilitation. Results were adjusted for age, sex, ethnicity, stroke severity/type, comorbid conditions, baseline function, and differences in baseline characteristics. Overall, 2,379 patients were eligible (mean [SD] age 75 [13.7] years 51.2% male 1,430 urban, 949 nonurban). Patients treated at nonurban hospitals were more likely to score in a higher mRS score category (greater disability) at 3 (adjusted odds ratio [aOR] 1.28, 95% CI 1.07–1.53), 6 (aOR 1.33, 95% CI 1.07–1.65), and 12 (aOR 1.31, 95% CI 1.06–1.62) months and were more likely to have died (aOR 1.57, 95% CI 1.17–2.12) or experienced recurrent stroke and vascular events at 12 months (aOR 1.94, 95% CI 1.14–3.29 and aOR 1.65, 95% CI 1.09–2.52). Fewer nonurban patients received recommended stroke interventions, including endovascular thrombectomy (aOR 0.25, 95% CI 0.13–0.49), acute stroke unit care (aOR 0.60, 95% CI 0.49–0.73), antiplatelet prescriptions (aOR 0.72, 95% CI 0.58–0.88), ≥60 minutes of daily physical therapy (aOR 0.55, 95% CI 0.40–0.77), and community rehabilitation (aOR 0.69, 95% CI 0.56–0.84). Patients managed at nonurban hospitals experience poorer stroke outcomes and reduced access to key stroke interventions across the entire care continuum. Efforts to improve access to high quality stroke care in nonurban hospitals should be a priority.
The International comparison of Systems of care and patient outcomes In minor Stroke and Tia (InSIST) study: A community-based cohort study
Publisher: SAGE Publications
Date: 04-01-2019
Abstract: Rapid response by health-care systems for transient ischemic attack and minor stroke (TIA/mS) is recommended to maximize the impact of secondary prevention strategies. The applicability of this evidence to Australian non-hospital-based TIA/mS management is uncertain. Within an Australian community setting we seek to document processes of care, establish determinants of access to care, establish attack rates and determinants of recurrent vascular events and other clinical outcomes, establish the performance of ABC2-risk stratification, and compare the processes of care and outcomes to those in the UK and New Zealand for TIA/mS. Recruiting practices containing approximately 51 full-time-equivalent general practitioners to recruit 100 TIA/mS per year over a four-year study period will provide sufficient power for each of our outcomes. An inception cohort study of patients with possible TIA/mS recruited from 16 general practices in the Newcastle-Hunter Valley-Manning Valley region of Australia. Potential TIA/mS will be ascertained by multiple overlapping methods at general practices, after-hours collaborative, and hospital in-patient and outpatient services. Participants’ index and subsequent clinical events will be adjudicated as TIA/mS or mimics by an expert panel. Process outcomes—whether the patient was referred for secondary care time from event to first patient presentation to a health professional time from event to specialist acute-access clinic appointment time from event to brain and vascular imaging and relevant prescriptions. Clinical outcomes—recurrent stroke and major vascular events and health-related quality of life. Community management of TIA/mS will be informed by this study.
Endovascular Thrombectomy for Ischemic Stroke Increases Disability-Free Survival, Quality of Life, and Life Expectancy and Reduces Cost
Publisher: Frontiers Media SA
Date: 14-12-2017
Combining Theta Burst Stimulation With Training After Subcortical Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2010
DOI: 10.1161/STROKEAHA.110.583278
Abstract: Background and Purpose— Repetitive transcranial magnetic stimulation of the primary motor cortex (M1) may improve outcomes after stroke. The aim of this study was to determine the effects of M1 theta burst stimulation (TBS) and standardized motor training on upper-limb function of patients with chronic stroke. Methods— Ten patients with chronic subcortical stroke and upper-limb impairment were recruited to this double-blind, crossover, sham-controlled study. Intermittent TBS of the ipsilesional M1, continuous TBS of the contralesional M1, and sham TBS were delivered in separate sessions in conjunction with standardized training of a precision grip task using the paretic upper limb. Results— Training after real TBS improved paretic-hand grip-lift kinetics, whereas training after sham TBS resulted in deterioration of grip-lift. Ipsilesional M1 excitability increased after intermittent TBS of the ipsilesional M1 but decreased after continuous TBS of the contralesional M1. Action Research Arm Test scores deteriorated when training followed continuous TBS of the contralesional M1, and this was correlated with reduced ipsilesional corticomotor excitability. Conclusions— Generally, TBS and training led to task-specific improvements in grip-lift. Specifically, continuous TBS of the contralesional M1 led to an overall decrement in upper-limb function, indicating that the contralesional hemisphere may play a pivotal role in recovery after stroke.
Reducing Ethnic and Geographic Inequities to Optimise New Zealand Stroke Care (REGIONS Care): Protocol for a Nationwide Observational Study
Publisher: JMIR Publications Inc.
Date: 12-01-2021
DOI: 10.2196/25374
Abstract: Stroke systems of care differ between larger urban and smaller rural settings and it is unclear to what extent this may impact on patient outcomes. Ethnicity influences stroke risk factors and care delivery as well as patient outcomes in nonstroke settings. Little is known about the impact of ethnicity on poststroke care, especially in Māori and Pacific populations. Our goal is to describe the protocol for the Reducing Ethnic and Geographic Inequities to Optimise New Zealand Stroke Care (REGIONS Care) study. This large, nationwide observational study assesses the impact of rurality and ethnicity on best practice stroke care access and outcomes involving all 28 New Zealand hospitals caring for stroke patients, by capturing every stroke patient admitted to hospital during the 2017-2018 study period. In addition, it explores current access barriers through consumer focus groups and consumer, carer, clinician, manager, and policy-maker surveys. It also assesses the economic impact of care provided at different types of hospitals and to patients of different ethnicities and explores the cost-efficacy of in idual interventions and care bundles. Finally, it compares manual data collection to routine health administrative data and explores the feasibility of developing outcome models using only administrative data and the cost-efficacy of using additional manually collected registry data. Regarding s le size estimates, in Part 1, Study A, 2400 participants are needed to identify a 10% difference between up to four geographic subgroups at 90% power with an α value of .05 and 10% to 20% loss to follow-up. In Part 1, Study B, a s le of 7645 participants was expected to include an estimated 850 Māori and 419 Pacific patients and to provide over 90% and over 80% power, respectively. Regarding Part 2, 50% of the patient or carer surveys, 40 provider surveys, and 10 focus groups were needed to achieve saturation of themes. The main outcome is the modified Rankin Scale (mRS) score at 3 months. Secondary outcomes include mRS scores EQ-5D-3L (5-dimension, 3-level EuroQol questionnaire) scores stroke recurrence vascular events death readmission at 3, 6, and 12 months cost of care and themes around access barriers. The study is underway, with national and institutional ethics approvals in place. A total of 2379 patients have been recruited for Part 1, Study A 6837 patients have been recruited for Part 1, Study B 10 focus groups have been conducted and 70 surveys have been completed in Part 2. Data collection has essentially been completed, including follow-up assessment however, primary and secondary analyses, data linkage, data validation, and health economics analysis are still underway. The methods of this study may provide the basis for future epidemiological studies that will guide care improvements in other countries and populations. DERR1-10.2196/25374
The colleges, Calman, and the new deal
Publisher: Elsevier BV
Date: 10-1997
DOI: 10.1016/S0140-6736(05)64065-2
Abstract: For the first time, we describe the whole genome of a yellow-pigmented, capsule-producing, pathogenic, and colistin-resistant
Intravenous Propofol Versus Volatile Anesthetics For Stroke Endovascular Thrombectomy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 23-08-2019
DOI: 10.1097/ANA.0000000000000639
Abstract: The choice of anesthetic technique for ischemic stroke patients undergoing endovascular thrombectomy is controversial. Intravenous propofol and volatile inhalational general anesthetic agents have differing effects on cerebral hemodynamics, which may affect ischemic brain tissue and clinical outcome. We compared outcomes in patients undergoing endovascular thrombectomy with general anesthesia who were treated with propofol or volatile agents. Consecutive endovascular thrombectomy patients treated using general anesthesia were identified from our prospective database. Baseline patient characteristics, anesthetic agent, and clinical outcomes were recorded. Functional independence at 3 months was defined as a modified Rankin Scale of 0 to 2. There were 313 patients (182 [58.1%] men mean±SD age, 64.7±15.9 y 257 [82%] anterior circulation), of whom 254 (81%) received volatile inhalational (desflurane or sevoflurane), and 59 (19%) received intravenous propofol general anesthesia. Patients with propofol anesthesia had more ischemic heart disease, higher baseline National Institutes of Health Stroke Scale scores, more basilar artery occlusion, and were less likely to be treated with intravenous thrombolysis. Multivariable logistic regression analysis showed that propofol anesthesia was associated with improved functional independence at 3 months (odds ratio=2.65 95% confidence interval, 1.14-6.22 P =0.03) and a nonsignificant trend toward reduced 3-month mortality (odds ratio=0.37 95% CI, 0.12-1.10 P =0.07). In stroke patients undergoing endovascular thrombectomy treated using general anesthesia, there may be a differential effect between intravenous propofol and volatile inhalational agents. These results should be considered hypothesis-generating and be tested in future randomized controlled trials.
Direct Bypass To Endovascular Capable Stroke Center Compared To Secondary Transfer From Primary Stroke Centers
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 02-2022
DOI: 10.1161/STR.53.SUPPL_1.79
Abstract: Introduction: All stroke care in our metropolitan region is provided by three primary stroke centers (PSCs) and a central endovascular thrombectomy capable stroke center (EVT-SC). There is a hybrid organizational structure with all potential large vessel occlusion (LVO) patients taken to the nearest stroke center during office-hours, and directly bypassed to the EVT-SC after-hours. Aim: To compare process times and EVT outcomes in PSC locality patients who were transferred to the EVT-SC by these two methods. Methods: Between August 2017 and February 2021, consecutive anterior LVO patients transferred via road with EVT initiation within 6 hours were included. Patients were grouped into method of presentation: 1) PSC locality patients directly bypassed to EVT-SC (‘EVT-SC direct’) 2) PSC locality patients taken to local PSC with subsequent transfer to EVT-SC (‘PSC-transfer’) 3) patients normally resident in the EVT-SC locality (‘EVT-SC local’). The primary outcome was 3-month functional independence (modified Rankin Scale score 0-2). Secondary outcomes included symptomatic intracranial hemorrhage, and mortality at 7-days and at 3-months. Results: 343 patients (142 women mean±SD age 66.5±16.0 years) were included. There were 91 (26.5%) EVT-SC direct, 168 (49.0%) PSC-transfer, and 84 (24.5%) EVT-SC local patients. For EVT-SC direct patients, the median (interquartile range) distance travelled was 13 (10-18) miles. EVT-SC direct patients were younger (mean±SD age 63.8±15.1 years versus 68.5±15.0 years P =0.02), had shorter LKN-to-thrombolysis (120 vs 147 minutes, P =0.004) and LKN-to-puncture times (190 vs 230 minutes, P 0.001), compared to the PSC-transfer patients. With multivariable logistic regression analysis, at 3-months EVT-SC direct patients were more likely to be functionally independent (OR=2.04, [95% CI, 1.12-3.73] P =0.02), and less likely to be dead (OR=0.33, [95% CI, 0.12-0.91] P =0.03). For every 100 patients directly bypassed to EVT-SC, there were 14 additional patients functionally independent and 9 less deaths at 3-months. Conclusion: The results of this study suggest where the distance is less than 20 miles, direct bypass to EVT-SC is associated with better process times and outcomes.
Expediting MRI-Based Proof-of-Concept Stroke Trials Using an Earlier Imaging End Point
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2009
DOI: 10.1161/STROKEAHA.108.532622
Abstract: Background and Purpose— Before Phase III trials of acute stroke therapies, proof-of-concept MRI trials are increasingly used to gauge the likelihood of success. Given that animal models use infarct volume as the end point, Phase II trials have aimed to translate the findings using infarct growth. These trials could be expedited if subacute diffusion-weighted imaging lesion volume replaced late T2-weighted lesion volume as the primary end point. Methods— In the Echoplanar Imaging Thrombolytic Evaluation Trial, patients with acute ischemic stroke presenting within 3 to 6 hours were randomized to tissue plasminogen activator or placebo. We assessed correlations between acute (Day 1), subacute (Day 3 to 5) as well as late (Day 90) lesion volumes and clinical outcome (National Institutes of Health Stroke Scale). We compared lesion growth between placebo- and tissue plasminogen activator-treated patients. Results— All 3 scans were performed in 72 of 101 patients (32 tissue plasminogen activator, 40 placebo). Median time to subacute imaging was 3 days (interquartile range, 2 to 4) and 90 days (interquartile range, 90 to 95) for the late scan. Increase in lesion volume from acute to subacute scans was smaller in the tissue plasminogen activator group compared with the placebo group (6.77 mL interquartile range, 2.30 to 49.10 versus 30.00 mL interquartile range, 7.19 to 85.93 P =0.03). Subsequent shrinkage did not reveal significant treatment effects. Correlation coefficient between acute and late lesion volumes was 0.81 ( P .01). Subacute and late lesion volumes were strongly correlated (rho=0.94, P .01). Correlation coefficient for acute, subacute, and late lesion volume and late National Institutes of Health Stroke Scale score was 0.64 ( P .01), 0.81 ( P .01), and 0.77 ( P .01), respectively. Conclusions— These findings suggest that subacute imaging at Day 3 after thrombolysis is an appropriate imaging end point for proof-of-concept MRI-based stroke treatment trials and can replace later MRI measurements.
Endovascular Therapy for Ischemic Stroke with Perfusion-Imaging Selection
Publisher: Massachusetts Medical Society
Date: 12-03-2015
Prediction of stroke outcome with echoplanar perfusion- and diffusion-weighted MRI
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-1998
DOI: 10.1212/WNL.51.2.418
Abstract: Objectives: We examined the utility of echoplanar magnetic resonance perfusion imaging and diffusion-weighted imaging (DWI) in predicting stroke evolution and outcome in 18 patients with acute hemispheric infarction. Methods: Patients were studied within 24 hours (mean, 12.2 hours), subacutely(mean, 4.7 days), and at outcome (mean, 84 days). Comparisons were made between infarction volumes as measured on perfusion imaging (PI) and isotropic DWI maps, clinical assessment scales (Canadian Neurological Scale, Barthel Index, and Rankin Scale), and final infarct volume (T2-weighted MRI). Results: Acute PI lesion volumes correlated with acute neurologic state, clinical outcome, and final infarct volume. Acute DWI lesions correlated less robustly with acute neurologic state, but correlated well with clinical outcome and final infarct volume. Three of six possible patterns of abnormalities were seen: PI lesion larger than DWI lesion (65%), PI lesion smaller than DWI lesion (12%), and DWI lesion but no PI lesion (23%). A pattern of a PI lesion larger than the DWI lesion predicted DWI expansion into surrounding hypoperfused tissue ( p 0.05). In the other two patterns, DWI lesions did not enlarge, suggesting that no significant increase in ischemic lesion size occurs in the absence of a larger perfusion deficit. Conclusions: Combined early PI and DWI can define different acute infarct patterns, which may allow the selection of rational therapeutic strategies based on the presence or absence of potentially salvageable ischemic tissue.
Hypertensive Response to Ischemic Stroke in the Normotensive Wistar Rat
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 09-2019
DOI: 10.1161/STROKEAHA.119.026459
Abstract: Over 80% of ischemic stroke patients show an abrupt increase in arterial blood pressure in the hours and days following ischemic stroke. Whether this poststroke hypertension is beneficial or harmful remains controversial and the underlying physiological basis is unclear. To investigate the dynamic cardiovascular response to stroke, adult Wistar rats (n=5–8 per group, 393±34 g) were instrumented with telemeters to blood pressure, intracranial pressure, renal sympathetic nerve activity, and brain tissue oxygen in the predicted penumbra (P o 2 ). After 2 weeks of recovery, cardiovascular signals were recorded for a 3-day baseline period, then ischemic stroke was induced via transient middle cerebral artery occlusion, or sham surgery. Cardiovascular signals were then recorded for a further 10 days, and the functional sensorimotor recovery assessed using the cylinder and sticky dot tests. Baseline values of all variables were similar between groups. Compared to sham, in the 2 days following stroke middle cerebral artery occlusion produced an immediate, transient rise above baseline in mean blood pressure (21±3 versus 2±4 mm Hg P .001), renal sympathetic nerve activity (54±11% versus 7±4% P =0.006), and cerebral perfusion pressure (12±5 versus 1±4 P ≤0.001). Intracranial pressure increased more slowly, peaking 3 days after middle cerebral artery occlusion (14±6 versus −1±1 mm Hg P .001). Treating with the antihypertensive agent nifedipine after stroke (1.5–0.75 mg/kg per hour SC) ameliorated poststroke hypertension (12±3 mm Hg on day 1 P =0.041), abolished the intracranial pressure increase (3±1 P .001) and reduced cerebral perfusion pressure (10±3 mm Hg P =0.017). Preventing poststroke hypertension affected neither the recovery of sensorimotor function nor infarct size. These findings suggest that poststroke hypertension is immediate, temporally matched to an increase in sympathetic outflow, and elevates cerebral perfusion pressure for several days after stroke, which may enhance cerebral perfusion. Preventing poststroke hypertension does not appear to worsen prognosis after stroke in young, normotensive, and otherwise healthy rats. An online visual overview is available for this article.
Predicting Recovery Potential for Individual Stroke Patients Increases Rehabilitation Efficiency
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2017
DOI: 10.1161/STROKEAHA.116.015790
Abstract: Several clinical measures and biomarkers are associated with motor recovery after stroke, but none are used to guide rehabilitation for in idual patients. The objective of this study was to evaluate the implementation of upper limb predictions in stroke rehabilitation, by combining clinical measures and biomarkers using the Predict Recovery Potential (PREP) algorithm. Predictions were provided for patients in the implementation group (n=110) and withheld from the comparison group (n=82). Predictions guided rehabilitation therapy focus for patients in the implementation group. The effects of predictive information on clinical practice (length of stay, therapist confidence, therapy content, and dose) were evaluated. Clinical outcomes (upper limb function, impairment and use, independence, and quality of life) were measured 3 and 6 months poststroke. The primary clinical practice outcome was inpatient length of stay. The primary clinical outcome was Action Research Arm Test score 3 months poststroke. Length of stay was 1 week shorter for the implementation group (11 days 95% confidence interval, 9–13 days) than the comparison group (17 days 95% confidence interval, 14–21 days P =0.001), controlling for upper limb impairment, age, sex, and comorbidities. Therapists were more confident ( P =0.004) and modified therapy content according to predictions for the implementation group ( P .05). The algorithm correctly predicted the primary clinical outcome for 80% of patients in both groups. There were no adverse effects of algorithm implementation on patient outcomes at 3 or 6 months poststroke. PREP algorithm predictions modify therapy content and increase rehabilitation efficiency after stroke without compromising clinical outcome. URL: anzctr.org.au . Unique identifier: ACTRN12611000755932.
Perfusion/Diffusion Mismatch Is Valid and Should Be Used for Selecting Delayed Interventions
Publisher: Springer Science and Business Media LLC
Date: 18-04-2012
DOI: 10.1007/S12975-012-0167-8
Abstract: The mismatch between a larger perfusion lesion and smaller diffusion lesion on magnetic resonance imaging is a validated signal of the ischemic penumbra, namely the region at risk in acute ischemic stroke that is critically hypoperfused and the target of reperfusion therapies. Clinical trials have shown strong correlations between reperfusion in mismatch patients and improved clinical outcomes. Attenuation of infarct growth is associated with reperfusion and corresponding clinical gains. Using computed tomography perfusion, the mismatch between relative cerebral blood flow or cerebral blood volume and perfusion delay is a comparable penumbral marker. Automated techniques allow rapid quantitative assessment of mismatch with thresholding to exclude benign oligemia. The penumbra is often present beyond the current 4.5-h time window, defined for the use of intravenous tPA. Treatment beyond this time point remains investigational. Although the efficacy of thrombolysis in mismatch patients requires further validation in randomized trials, there is now sufficient evidence to recommend that advanced neuroimaging of mismatch should be used for selection of delayed therapies in phase 3 trials.
Contrast-Associated Acute Kidney Injury in Endovascular Thrombectomy Patients With and Without Baseline Renal Impairment
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2019
DOI: 10.1161/STROKEAHA.119.026738
Abstract: In ischemic stroke, baseline renal impairment is present in 20 to 35% of patients and may increase the risk of contrast-associated acute kidney injury (CA-AKI). We aimed to determine whether endovascular thrombectomy (EVT) patients with baseline renal impairment are at increased risk of CA-AKI. Consecutive EVT patients were identified from a prospective database. Patients were stratified by estimated glomerular filtration rate. The primary outcome was CA-AKI assessed at 24 to 72 hours following EVT, defined as an increase in serum creatinine of ≥26.5 µmol/L or 1.5× baseline serum creatinine. Secondary outcomes included requirement for renal replacement therapy and 3-month mortality. Three hundred thirty-three EVT patients (201 men mean±SD age 63.9±15.8 years) were included. The mean±SD iohexol contrast volume used in diagnostic and EVT imaging was 236±77 mL per patient. CA-AKI occurred in 11 (3.3%) patients none required renal replacement therapy, but 4 of 11 (36.4%) had died by 3 months. Propensity score–adjusted logistic regression showed that estimated glomerular filtration rate mL/(min·1.73 m 2 ) was a significant predictor of CA-AKI (odds ratio, 19.93 95% CI, 2.33–170.74 P =0.006). The dose of contrast was not associated with an increased risk of CA-AKI ( P .05). Multiple logistic regression adjusted for potential confounders demonstrated that CA-AKI was independently associated with increased mortality (odds ratio, 4.68 95% CI, 1.05–20.97 P =0.04). There is utility in obtaining baseline creatinine levels to identify patients at risk of CA-AKI and to establish a diagnosis of CA-AKI in patients with subsequent creatinine rises. However, contrast-requiring diagnostic imaging and EVT should not be delayed by waiting for the results of baseline renal function.
Postthrombolysis blood pressure elevation is associated with hemorrhagic transformation
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2010
DOI: 10.1161/STROKEAHA.109.563767
Abstract: Background and Purpose— Reliable predictors of hemorrhagic transformation (HT) after stroke thrombolysis have not been identified. We analyzed hemorrhage in a randomized trial of tissue plasminogen activator (t-PA) vs placebo in ischemic stroke patients. We hypothesized that acute diffusion-weighted imaging (DWI) lesion volumes would be larger and blood pressures would be higher in patients with HT. Methods— HT was assessed 2 to 5 days after treatment in 97 patients. Hemorrhage was assessed by using susceptibility-weighted imaging sequences and was classified as petechial hemorrhagic infarction (HI) or parenchymal hematoma (PH). Results— PH was more frequent in t-PA– (11/49) than in placebo- (4/48) treated patients ( P =0.049). Patients with PH had larger DWI lesion volumes (63.1±56.1 mL) than did those without HT (27.6±39.0 mL, P =0.033). There were no differences in baseline systolic blood pressure (SBP) between patients with and without hemorrhage. Weighted average SBP 24 hours after treatment was higher in patients with PH (159.4±18.8 mL, P .011) relative to those without HT (143.1±20.0 mL). Multinomial logistic regression indicated that PH was predicted by DWI lesion volume (odds ratio=1.16 per 10 mL 95% CI, 1.03 to 1.30), atrial fibrillation (odds ratio=9.33 95% CI, 2.30 to 37.94), and 24-hour weighted average SBP (odds ratio=1.59 per 10 mm Hg 95% CI, 1.14 to 2.23). Conclusions— Pretreatment DWI lesion volume and postthrombolysis BP are both predictive of HT. Consideration should be given to excluding patients with very large baseline DWI volumes from t-PA therapy and to more stringent BP control after stroke thrombolysis.
Intracranial Reserve in Ischemic Stroke: Is the Skull Half-Full or Half-Empty?
Publisher: Springer Science and Business Media LLC
Date: 21-09-2020
End the confusion: general anaesthesia improves patient outcomes in endovascular thrombectomy
Publisher: Elsevier BV
Date: 10-2022
DOI: 10.1016/J.BJA.2022.06.018
Abstract: Expert physiological and pharmacological care by anaesthetists is required in all stroke endovascular thrombectomy cases. RCTs show clinical benefits in recanalisation rates and functional recovery after endovascular thrombectomy with general anaesthesia compared with sedation. Many stroke centres will require wholesale reorganisation of stroke pathways to ensure anaesthesia services are available for all cases. Anaesthetists have an integral role in improving clinical outcomes in large vessel occlusion stroke.
Management problems of spontaneous ICH
Publisher: Mark Allen Group
Date: 04-2005
DOI: 10.12968/HMED.2005.66.4.18447
Abstract: The management of spontaneous intracerebral haemorrhage (ICH) can be challenging for hospital doctors. Although the management of ICH is covered in stroke guidelines, many difficult clinical questions remain. In this article the authors suggest approaches to ten common and difficult questions.
Platelet-Reactive Antibodies in Patients after Ischaemic Stroke—An Epiphenomenon or a Natural Protective Mechanism
Publisher: MDPI AG
Date: 09-11-2020
DOI: 10.3390/IJMS21218398
Abstract: Ischaemic brain damage induces autoimmune responses, including the production of autoantibodies with potential neuroprotective effects. Platelets share unexplained similarities with neurons, and the formation of anti-platelet antibodies has been documented in neurological disorders. The aim of this study was to investigate the presence of anti-platelet antibodies in the peripheral blood of patients after ischaemic stroke and determine any clinical correlations. Using a flow cytometry-based platelet immunofluorescence method, we detected platelet-reactive antibodies in 15 of 48 (31%) stroke patients and two of 50 (4%) controls (p 0.001). Western blotting revealed heterogeneous reactivities with platelet proteins, some of which overlapped with brain proteins. Stroke patients who carried anti-platelet antibodies presented with larger infarcts and more severe neurological dysfunction, which manifested as higher scores on the National Institutes of Health Stroke Scale (NIHSS p = 0.009), but they had a greater recovery in the NIHSS by the time of hospital discharge (day 7 ± 2) compared with antibody-negative patients (p = 0.043). Antibodies from stroke sera reacted more strongly with activated platelets (p = 0.031) and inhibited platelet aggregation by up to 30.1 ± 2.8% (p 0.001), suggesting the potential to interfere with thrombus formation. In conclusion, platelet-reactive antibodies can be found in patients soon after ischaemic stroke and correlate with better short-term outcomes, suggesting a potential novel mechanism limiting thrombosis.
Patient, carer and health worker perspectives of stroke care in New Zealand: a mixed methods survey.
Publisher: Informa UK Limited
Date: 05-09-2022
DOI: 10.1080/09638288.2022.2117862
Abstract: It is important to understand how consumers (person with stroke/family member/carer) and health workers perceive stroke care services. Consumers and health workers from across New Zealand were surveyed on perceptions of stroke care, access barriers, and views on service centralisation. Quantitative data were summarised using descriptive statistics whilst thematic analysis was used for free-text answers. Of 149 consumers and 79 health workers invited to complete a survey, 53 consumers (36.5%) and 41 health workers (51.8%) responded. Overall, 40/46 (87%) consumers rated stroke care as 'good/excellent' compared to 24/41 (58.6%) health workers. Approximately 72% of consumers preferred to transfer to a specialised hospital. We identified three major themes related to perceptions of stroke care: 1) 'variability in care by stage of treatment' 2) 'impact of communication by health workers on care experience' and 3) 'inadequate post-acute services for younger patients'. Four access barrier themes were identified: 1) 'geographic inequities' 2) 'knowing what is available' 3) 'knowledge about stroke and available services' and 4) 'healthcare system factors'. Perceptions of stroke care differed between consumers and health workers, highlighting the importance of involving both in service co-design. Improving communication, post-hospital follow-up, and geographic equity are key areas for improvement.Implications for rehabilitationProvision of detailed information on stroke recovery and available services in the community is recommended.Improvements in the delivery of post-hospital stroke care are required to optimise stroke care, with options including routine phone follow up appointments and wider development of early supported discharge services.Stroke rehabilitation services should continue to be delivered 'close to home' to allow community integration.Telehealth is a likely enabler to allow specialist urban clinicians to support non-urban clinicians, as well as increasing the availability and access of community rehabilitation.
Repetitive stimulation of premotor cortex affects primary motor cortex excitability and movement preparation
Publisher: Elsevier BV
Date: 07-2009
DOI: 10.1016/J.BRS.2009.01.001
Abstract: Repetitive transcranial magnetic stimulation can be used to explore functional connectivity between cortical areas. To determine the effects of two theta burst stimulation (TBS) patterns (intermittent, iTBS and continuous, cTBS) of left dorsal premotor cortex (PMd). Left PMd was identified in 11 participants using functional magnetic resonance imaging (fMRI), during performance of complex sequential finger movements. Each participant received iTBS, cTBS, or sham TBS of left PMd in three separate sessions within a randomized, single-blind design. The speed and accuracy of simple and complex sequential reaction time (RT) task performance was measured before and after TBS. The excitability of primary motor cortex (M1) bilaterally, and interhemispheric facilitation from left PMd to right M1, were also measured before and after TBS. iTBS sped up the preparation of complex sequences performed with the right hand, with no detectable changes in M1 excitability. RT performance was maintained after cTBS, in the presence of increased left M1 excitability and suppressed right M1 excitability. Facilitatory and inhibitory TBS protocols applied to left PMd differentially alter corticomotor excitability and behavior, which suggests that these protocols affect different neuronal populations.
Stroke Incidence by Major Pathological Type and Ischemic Subtypes in the Auckland Regional Community Stroke Studies
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2018
DOI: 10.1161/STROKEAHA.117.019358
Abstract: Major pathological stroke types (ischemic stroke [IS], primary intracerebral hemorrhage [ICH], and subarachnoid hemorrhage) and IS subtypes, have differing risk factors, management, and prognosis. We report changes in major stroke types and IS subtypes incidence during 10 years using data from the ARCOS (Auckland Regional Community Stroke Study) III performed during 12 months in 2002 to 2003 and the fourth ARCOS study (ARCOS-IV) performed in 2011 to 2012. ARCOS-III and ARCOS-IV were population-based registers of all new strokes in the greater Auckland region (population aged years, 1 119 192). Strokes were classified into major pathological types (IS, ICH, subarachnoid hemorrhage, and undetermined type). Crude annual age-, sex-, and ethnic-specific stroke incidence with 95% confidence intervals was calculated. ISs were subclassified using TOAST (Trial of ORG 10172 in Acute Stroke Treatment) criteria into 5 etiologic groups. Rate ratios with 95% confidence intervals were calculated for differences in age-standardized rates between the 2 studies. In ARCOS-IV, there were 1329 (81%) ISs, 211 (13%) ICHs, 79 (5%) subarachnoid hemorrhages, and 24 (1%) undetermined type strokes. The proportional distribution of IS subtypes was 29% cardioembolism, 21% small-vessel occlusion, 15% large-artery atherosclerosis, 5% other determined etiology, and 31% undetermined type. Between 2002 and 2011, age-standardized incidence decreased for subarachnoid hemorrhage (rate ratios, 0.73 95% confidence intervals, 0.54–0.99) and undetermined type (rate ratios, 0.14 95% confidence intervals, 0.09–0.22). Rates were stable for IS and ICH. Among IS subtypes, large-artery atherosclerosis and small-vessel occlusion rates increased significantly. The frequency of all risk factors increased in IS. Ethnic differences were observed for both stroke subtype rates and their risk factor frequencies. A lack of change in IS and ICH incidence may reflect a trend toward increased incidence of younger strokes. Increased rates of large-artery atherosclerosis and small-vessel occlusion are associated with increased smoking and high blood pressure. Ethnic differences in the proportional distribution of pathological stroke subtypes suggest differential exposure and susceptibility to risk factors.
Routine Use of Tenecteplase for Thrombolysis in Acute Ischemic Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2021
DOI: 10.1161/STROKEAHA.120.030859
Abstract: In ischemic stroke, intravenous tenecteplase is noninferior to alteplase in selected patients and has some practical advantages. Several stroke centers in New Zealand changed to routine off-label intravenous tenecteplase due to improved early recanalization in large vessel occlusion, inconsistent access to thrombectomy within stroke networks, and for consistency in treatment protocols between patients with and without large vessel occlusion. We report the feasibility and safety outcomes in tenecteplase-treated patients. We performed a retrospective analysis of consecutive patients thrombolyzed with intravenous tenecteplase at 1 comprehensive and 2 regional stroke centers from July 14, 2018, to February 29, 2020. We report the baseline clinical characteristics, rates of symptomatic intracranial hemorrhage, and angioedema. These were then compared with patient outcomes with those treated with intravenous alteplase at 2 other comprehensive stroke centers. Multivariable mixed-effects logistic regression models were performed assessing the association of tenecteplase with symptomatic intracranial hemorrhage and independent outcome (modified Rankin Scale score, 0–2) at day 90. There were 165 patients treated with tenecteplase and 254 with alteplase. Age (75 versus 74 years), sex (56% versus 60% male), National Institutes of Health Stroke Scale scores (8 versus 10), median door-to-needle times (47 versus 48 minutes), or onset-to-needle time (129 versus 130 minutes) were similar between the groups. Symptomatic intracranial hemorrhage occurred in 3 (1.8% [95% CI, 0.4–5.3]) tenecteplase patients compared with 7 (2.7% [95% CI, 1.1–5.7]) alteplase patients ( P =0.75). There were no differences between tenecteplase and alteplase in the rates of angioedema (4 [2.4% 95% CI, 0.7–6.2] versus 1 [0.4% 95% CI, 0.01–2.2], P =0.08) or 90-day functional independence (100 [61%] versus 140 [57%], P =0.47), respectively. In mixed-effects logistic regression models, there was no significant association between thrombolytic choice and symptomatic intracranial hemorrhage (odds ratio tenecteplase, 0.62 [95% CI, 0.14–2.80], P =0.53) or functional independence (odds ratio tenecteplase, 1.20 [95% CI, 0.74–1.95], P =0.46). Routine use of tenecteplase for stroke thrombolysis was feasible and had comparable safety profile and outcome to alteplase.
Bridging Thrombolysis and ASPECTS in Patients With Stroke Treated With Endovascular Thrombectomy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2023
Abstract: In patients with stroke with large‐vessel occlusion and extensive ischemic change denoted by low Alberta Stroke Programme Early Computed Tomography Score (ASPECTS), the role of bridging thrombolysis before endovascular thrombectomy (EVT) is still to be determined. We aimed to examine the impact of ischemic change on clinical outcomes and how this is modified by bridging thrombolysis in patients treated with EVT. Consecutive patients undergoing anterior circulation EVT from a prospectively collected registry were included in this retrospective analysis. ASPECTS was evaluated from baseline noncontrast computed tomography scans with lower scores indicating larger areas of ischemic change. Outcome measures included symptomatic intracranial hemorrhage and functional independence (modified Rankin Scale score, 0–2) at day 90. Multivariable logistic regression models with interaction terms between ASPECTS and bridging thrombolysis were created. ASPECTS was treated as numeric variable in the primary analysis and trichotomized (ASPECTS ≤5, 6–8, 9–10) in a sensitivity analysis. A total of 872 patients undergoing EVT (384 women, mean±SD age of 67±15, baseline National Institute of Health Stroke Scale 16 [interquartile range, 11–20]) were included. A total of 549 (63%) patients were transferred from primary stroke centers for EVT and 436 (50%) received bridging intravenous thrombolysis with alteplase. On baseline computed tomography scan, median [interquartile range] ASPECTS was 8 [7–9], with 408 (47%) having minimal (ASPECTS 9–10), 376 (43%) moderate (ASPECTS 6–8), and 88 (10%) extensive (ASPECTS ≤5) ischemic change. With decreasing numeric ASPECTS, the probability of functional independence reduced (ASPECTS main effect adjusted odds ratio, 1.36 [95% CI, 1.23–1.52] P .001), but this was attenuated in those with bridging thrombolysis (interaction P =0.046). This interaction was significant for patients transferred to the EVT center after thrombolysis (interaction P =0.03) but not for patients presenting directly to the EVT center (interaction P =0.46). The interaction between ASPECTS and bridging thrombolysis was not significant when ASPECTS was split into the 3 categories ( P =0.35). In a cohort of patients undergoing EVT where most were transferred from a primary stroke center, ischemic change was associated with decreased probability functional independence, but this effect was attenuated with bridging thrombolysis. These results suggest that patients with large areas of ischemic change may still benefit from the earliest possible reperfusion afforded by bridging thrombolysis.
Assessing Reperfusion and Recanalization as Markers of Clinical Outcomes After Intravenous Thrombolysis in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET)
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2009
DOI: 10.1161/STROKEAHA.108.543595
Abstract: Background and Purpose— Reperfusion and recanalization have both been used as surrogate markers of clinical outcome in trials of stroke thrombolysis. We aimed to prove that the beneficial impact of recanalization with intravenous tissue plasminogen activator on clinical outcomes is attributable to reperfusion in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). Methods— EPITHET was a prospective, randomized, placebo-controlled trial of intravenous tissue plasminogen activator in the 3- to 6-hour window. Reperfusion was defined as % reduction in magnetic resonance perfusion-weighted imaging lesion volume and recanalization as improvement of MR angiographic Thrombolysis In Myocardial Infarction grading by ≥2 points from baseline to Day 3 to 5. Results— At Day 3 to 5, reperfusion and recanalization with intravenous tissue plasminogen activator were strongly correlated. Reperfusion was associated with improved clinical outcome independent of whether recanalization occurred. In contrast, recanalization was not associated with clinical outcome when reperfusion was included as a covariate in regression analyses. Conclusion— Reperfusion is a surrogate marker of clinical outcomes independent of recanalization based on the criteria applied in EPITHET. The impact of recanalization on clinical outcomes was attributable to reperfusion.
The PREP algorithm predicts potential for upper limb recovery after stroke
Publisher: Oxford University Press (OUP)
Date: 10-06-2012
DOI: 10.1093/BRAIN/AWS146
Abstract: Stroke is a leading cause of adult disability and the recovery of motor function is important for independence in activities of daily living. Predicting motor recovery after stroke in in idual patients is difficult. Accurate prognosis would enable realistic rehabilitation goal-setting and more efficient allocation of resources. The aim of this study was to test and refine an algorithm for predicting the potential for recovery of upper limb function after stroke. Forty participants were prospectively enrolled within 3 days of ischaemic stroke. First, shoulder abduction and finger extension strength were graded 72 h after stroke onset to compute a shoulder abduction and finger extension score. Secondly, transcranial magnetic stimulation was used to assess the functional integrity of descending motor pathways to the affected upper limb. Third, diffusion-weighted magnetic resonance imaging was used to assess the structural integrity of the posterior limbs of the internal capsules. Finally, these measures were combined in the PREP algorithm for predicting an in idual's potential for upper limb recovery at 12 weeks, measured with the Action Research Arm Test. A cluster analysis was used to independently group patients according to Action Research Arm Test score at 12 weeks, for comparison with predictions from the PREP algorithm. There was excellent correspondence between the cluster analysis of Action Research Arm Test score at 12 weeks and predictions made with the PREP algorithm. The algorithm had positive predictive power of 88%, negative predictive power of 83%, specificity of 88% and sensitivity of 73%. This study provides preliminary data in support of the PREP algorithm for the prognosis of upper limb recovery in in idual patients. PREP may enable tailored planning of rehabilitation and more accurate stratification of patients in clinical trials.
Predicting Motor Outcomes Using Atlas-Based Voxel Features of Post-Stroke Neuroimaging: A Scoping Review
Publisher: SAGE Publications
Date: 16-05-2023
DOI: 10.1177/15459683231173668
Abstract: Atlas-based voxel features have the potential to aid motor outcome prognostication after stroke, but are seldom used in clinically feasible prediction models. This could be because neuroimaging feature development is a non-standardized, complex, multistep process. This is a barrier to entry for researchers and poses issues for reproducibility and validation in a field of research where s le sizes are typically small. The primary aim of this review is to describe the methodologies currently used in motor outcome prediction studies using atlas-based voxel neuroimaging features. Another aim is to identify neuroanatomical regions commonly used for motor outcome prediction. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol was constructed and OVID Medline and Scopus databases were searched for relevant studies. The studies were then screened and details about imaging modality, image acquisition, image normalization, lesion segmentation, region of interest determination, and imaging measures were extracted. Seventeen studies were included and examined. Common limitations were a lack of detailed reporting on image acquisition and the specific brain templates used for normalization and a lack of clear reasoning behind the atlas or imaging measure selection. A wide variety of sensorimotor regions relate to motor outcomes and there is no consensus use of one single sensorimotor atlas for motor outcome prediction. There is an ongoing need to validate imaging predictors and further improve methodological techniques and reporting standards in neuroimaging feature development for motor outcome prediction post-stroke.
Cannabis and Stroke
Publisher: Elsevier
Date: 2017
Extending thrombolysis to 4·5–9 h and wake-up stroke using perfusion imaging: a systematic review and meta-analysis of individual patient data
Publisher: Elsevier BV
Date: 07-2019
Prediction of the Final Infarct Volume within 6 h of Stroke Using Single Photon Emission Computed Tomography with Technetium-99m Hexamethylpropylene Amine Oxime
Publisher: S. Karger AG
Date: 2001
DOI: 10.1159/000047623
Abstract: i Background: /i A simple method to predict the final infarct volume within 6 h of onset of hemispheric ischemic stroke based on the measurement of cerebral blood flow (CBF) using single photon emission computed tomography (SPECT) with techneticum-99m hexamethylpropylene amine oxime ( sup m /sup Tc-HMPAO) was investigated in a clinical model involving patients without definite early reperfusion or clinical recovery. i Methods: /i A group of 16 patients (group 1) was used to establish the methodology, which was then validated in a second group of 14 patients (group 2). The final infarct volume was defined using computed tomography (CT) performed at least 7 days after stroke. The relative CBF threshold value, expressed as a percentage of the mean contralateral hemispheric value, which most closely estimated the final infarct size on coregistered CT was established for each patient. i Results: /i The mean threshold CBF value for group 1 was 63.7%. When this value was used to predict infarct size in group 2, a close correlation was observed between the actual and the estimated sizes (r = 0.973, p 0.0001). This value was not time dependent. i Conclusions: /i If no significant early reperfusion or clinical recovery occurs, a CBF threshold value of 63.7% on sup m /sup Tc-HMPAO SPECT performed within 6 h of stroke onset will reliably predict the final infarct size.
Comparison of MRI perfusion imaging and single photon emission computed tomography in chronic stroke
Publisher: S. Karger AG
Date: 2001
DOI: 10.1159/000047624
Abstract: There have been few direct comparisons between MR perfusion-weighted imaging (PWI) and established perfusion imaging techniques, and none in chronic stroke. We therefore studied 17 chronic hemispheric infarction patients (mean, 90 days) and compared hypoperfusion volumes determined from PWI maps of relative cerebral blood flow (rCBF) and volume (rCBV), and mean transit time (rMTT) with those measured with sup /sup Tc-HMPAO single photon emission computed tomography (SPECT). Comparisons were also made between infarct size (T sub /sub -WI) and clinical scales. Correlations were found between lesion location and volume in all three PWI hemodynamic parameter maps with clinical state and lesions on SPECT and T sub /sub -WI. In 3 patients, rCBF and rCBV lesions extended well beyond the borders of moderate-sized infarctions. We conclude that in chronic stroke, PWI can delineate regions of abnormal perfusion that reflect the degree of functional impairment and structural damage. The finding of peri-infarct hypoperfusion suggests that PWI may have the potential to provide a rapid and non-invasive template against which interventional strategies aimed at promoting functional recovery may be investigated.
Intravenous thrombolysis is unsafe in stroke due to infective endocarditis
Publisher: Wiley
Date: 02-2014
DOI: 10.1111/IMJ.12343
Abstract: Embolic stroke is the most common neurological complication of infective endocarditis and a major source of morbidity and mortality. Septic embolism is considered a contraindication to intravenous thrombolysis in patients with ischaemic stroke because of concerns over an increased risk of intracranial haemorrhage. We describe a patient with occult endocarditis who was treated with thrombolysis for acute stroke and review other cases reported in the literature.
Methodology of a Population-Based Stroke and TIA Incidence and Outcomes Study: The Auckland Regional Community Stroke Study (ARCOS IV) 2011–2012
Publisher: SAGE Publications
Date: 27-10-2013
DOI: 10.1111/IJS.12108
Abstract: Stroke is a leading cause of death and disability worldwide. Stroke burden is immense as it leads to premature deaths, leaves survivors with ongoing disabilities, and has a major financial impact on the in idual, their families, and the community. Reliable, high-quality evidence is needed on stroke risk factors, incidence, and outcomes to provide information on how best to reduce this burden. Population-based studies are regarded as the ‘gold-standard’ of measuring disease burden but are not common due to the logistical and financial challenges they present. The Auckland Regional Community Stroke Studies are among a few in the world that have been carried out at a population level and at regular intervals. The aim of the fourth Auckland Regional Community Stroke Studies IV is to examine the current measures of stroke incidence, prevalence, and outcomes as well the trends over four decades. This article describes the methodology of the Auckland Regional Community Stroke Studies IV with stroke and transient ischemic attacks cases registered over a 12-month period from March 1, 2011 to February 29, 2012. The methodology described may be used as a guide in order to design similar population-based stroke incidence and outcome studies in other countries and populations, thus facilitating the collection of most consistent and accurate stroke epidemiological data.
Intravenous alteplase and endovascular clot retrieval following reversal of dabigatran with idarucizumab
Publisher: BMJ
Date: 06-10-2017
Effects of non-target leg activation, TMS coil orientation, and limb dominance on lower limb motor cortex excitability
Publisher: Elsevier BV
Date: 2017
DOI: 10.1016/J.BRAINRES.2016.11.004
Abstract: Transcranial magnetic stimulation (TMS) is used to examine corticospinal tract integrity after stroke, however, generating motor-evoked potentials (MEPs) in the lower limb (LL) can be difficult. Previous studies have used activation of the target leg to facilitate MEPs in the LL but this may not be possible after stroke due to hemiplegia. The dominance of the target limb may also be important, however the neurophysiological effects of LL dominance are not known. We investigated whether voluntary activation of the non-target leg combined with optimal TMS coil orientation increases corticomotor excitability in healthy adults, and whether limb dominance influences these results. TMS was delivered to induce a posterior-anterior (PA) and a medial-lateral (ML) cortical current in 22 healthy adults. MEPs were recorded in tibialis anterior (TA) with the participant at rest and when activating the non-target leg. We found that non-target leg activation increased corticomotor excitability in the target leg (reduced rest motor threshold (RMT) and MEP latency, and increased recruitment curve slope). ML cortical current also reduced RMT and MEP latency. The degree of footedness correlated with the degree of RMT asymmetry, with a PA but not ML cortical current direction. In summary, cross-facilitation by activating the non-target leg in a task requiring postural stabilisation and inducing ML current increase corticomotor excitability regardless of limb dominance. This protocol may have practical application in testing CST integrity after stroke when paretic limb thresholds are high, by increasing the likelihood of eliciting a MEP.
Proportional Recovery From Lower Limb Motor Impairment After Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 05-2017
DOI: 10.1161/STROKEAHA.116.016478
Abstract: In people with preserved corticospinal tract (CST) function after stroke, upper limb impairment resolves by ≈70% within 3 months. This is known as the proportional recovery rule. Patients without CST function do not fit this rule and have worse upper limb outcomes. This study investigated resolution of motor impairment in the lower limb (LL). Patients with stroke and LL weakness were assessed 3 days and 3 months after stroke with the LL Fugl–Meyer. CST integrity was determined in a subset of patients using transcranial magnetic stimulation to test for LL motor-evoked potentials and magnetic resonance imaging to measure CST lesion load. Linear regression analyses were conducted to predict resolution of motor impairment (ΔFugl–Meyer) including factors initial impairment, motor-evoked potential status, CST lesion load, and LL therapy dose. Thirty-two patients completed 3-month follow-up and recovered 74% (95% confidence interval, 60%–88%) of initial LL motor impairment. Initial impairment was the only significant predictor of resolution of motor impairment. There was no identifiable cluster of patients who did not fit the proportional recovery rule. Measures of CST integrity did not predict proportional LL recovery. LL impairment resolves by ≈70% within 3 months after stroke. The absence of a nonfitter group may be because of differences in the neuroanatomical organization of descending motor tracts to the upper limb and LL. Proportional recovery of the LL is not influenced by therapy dose providing further evidence that it reflects a fundamental biological process.
Improving Adherence to Secondary Stroke Prevention Strategies Through Motivational Interviewing
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-2015
DOI: 10.1161/STROKEAHA.115.011003
Abstract: Stroke recurrence rates are high (20%–25%) and have not declined over past 3 decades. This study tested effectiveness of motivational interviewing (MI) for reducing stroke recurrence, measured by improving adherence to recommended medication and lifestyle changes compared with usual care. Single-blind, prospective phase III randomized controlled trial of 386 people with stroke assigned to either MI treatment (4 sessions at 28 days, 3, 6, and 9 months post stroke) or usual care with outcomes assessed at 28 days, 3, 6, 9, and 12 months post stroke. Primary outcomes were change in systolic blood pressure and low-density lipoprotein cholesterol levels as indicators of adherence at 12 months. Secondary outcomes included self-reported adherence, new stroke, or coronary heart disease events (both fatal and nonfatal) quality of life (Short Form-36) and mood (Hospital Anxiety and Depression Scale). MI did not significantly change measures of blood pressure (mean difference in change, −0.2.35 [95% confidence interval, −6.16 to 1.47]) or cholesterol (mean difference in change, −0.0.12 [95% confidence interval, −0.30 to 0.06]). However, it had positive effects on self-reported medication adherence at 6 months (1.979 95% confidence interval, 0.98–3.98 P =0.0557) and 9 months (4.295 95% confidence interval, 1.56–11.84 P =0.0049) post stroke. Improvement across other measures was also observed, but the differences between MI and usual care groups were not statistically significant. MI improved self-reported medication adherence. All other effects were nonsignificant, though in the direction of a treatment effect. Further study is required to determine whether MI leads to improvement in other important areas of functioning (eg, caregiver burden). URL: www.anzctr.org.au . Unique identifier: ACTRN-12610000715077.
Trends in Ethnic Disparities in Stroke Incidence in Auckland, New Zealand, During 1981 to 2003
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2006
DOI: 10.1161/01.STR.0000195131.23077.85
Abstract: Background and Purpose— Although geographical variations in stroke rates are well documented, limited data exist on temporal trends in ethnic-specific stroke incidence. Methods— We assessed trends in ethnic-specific stroke rates using standard diagnostic criteria and community-wide surveillance procedures in Auckland, New Zealand (NZ) in 1981 to 1982, 1991 to 1992, and 2002 to 2003. Indirect and direct methods were used to adjust first-ever (incident) and total (attack) rates for changes in the structure of the population and reported with 95% CIs. Ethnicity was self-defined and categorized as “NZ/European,” “Maori,” “Pacific peoples,” and “Asian and other.” Results— Stroke attack (19% 95% CI, 11% to 26%) and incidence rates (19% 95% CI, 12% to 24%) declined significantly in NZ/Europeans from 1981 to 1982 to 2002 to 2003. These rates remained high or increased in other ethnic groups, particularly for Pacific peoples in whom stroke attack rates increased by 66% (95% CI 11% to 225%) over the periods. Some favorable downward trends in vascular risk factors, such as cigarette smoking, were counterbalanced by increasing age, body mass index, and diabetes in certain ethnic groups. Conclusions— Divergent trends in ethnic-specific stroke incidence and attack rates, and of associated risk factors, have occurred in Auckland over recent decades. The findings provide mixed views as to the future burden of stroke in populations undergoing similar lifestyle and structural changes.
Differences between self-reported and verified adverse cardiovascular events in a randomised clinical trial
Publisher: BMJ
Date: 2013
Significance of Acute Multiple Brain Infarction on Diffusion-Weighted Imaging
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2000
Abstract: Background and Purpose —Diffusion-weighted imaging (DWI) is superior to conventional MRI in identification of small new ischemic lesions and discrimination of recent infarcts from old ones. Thus, this technique is useful in the detection of acute multiple brain infarcts (AMBI). We sought to determine the frequency and the topographical and etiologic patterns of AMBI detected on DWI. Methods —We studied 329 consecutive ischemic stroke patients who underwent DWI and MRI/MR angiography within 4 days of stroke onset. AMBI was defined as noncontiguous high signal intensities on DWI in vascular territory. Stroke mechanism was determined according to the criteria of the Trial of Org 10172 in Acute Stroke Treatment (TOAST). Results —We detected AMBI in 95 patients (28.9%). AMBI in anterior circulation was found in 62 cases: in 1 hemisphere in 42 (group A) and in bilateral hemispheres in 20 (group B). Twenty-two patients had AMBI in the posterior circulation (group C) and 11 in both anterior and posterior circulations (group D). The most frequent cause of stroke was large-artery atherosclerosis in groups A (33/42), B (9/20), and C (15/22) ( P =0.02) and cardioembolism in group D (6/11) ( P =0.02). Elevated fibrinogen or hematocrit was significantly associated with group B ( P =0.01). In 9 patients in groups B and D, anatomic variations of anterior or posterior cerebral arteries or patent posterior communicating artery contributed to AMBI. Conclusions —Different topographical patterns of AMBI are associated with different vascular pathologies and stroke mechanisms. Hemorheologic abnormality or vascular anatomic variations may be contributing factors in the pathogenesis of AMBI in bilateral cerebral hemispheres or in both anterior and posterior circulations.
Plasma cyclic glycine proline/IGF-1 ratio predicts clinical outcome and recovery in stroke patients
Publisher: Wiley
Date: 27-02-2019
DOI: 10.1002/ACN3.743
The influence of diabetes mellitus and hyperglycaemia on stroke incidence and outcome
Publisher: Elsevier BV
Date: 11-2002
Abstract: Diabetes mellitus is a complex metabolic syndrome with significant effects on the systemic and cerebral vasculature. The incidence and severity of ischaemic stroke are increased by the presence of diabetes, and outcome from stroke is poorer. More than one third of patients admitted with acute stroke are hyperglycaemic at presentation. Reasons for the altered prognosis in diabetes associated stroke are multifactorial. A direct influence of hyperglycaemia at the time of ischaemia is likely to be important. The use of novel methods to delineate stroke topography and pathophysiology such as MR spectroscopy, diffusion and perfusion weighted MRI appear helpful in delineating the effects of hyperglycaemia on stroke pathophysiology. Randomised clinical trials to determine optimal management for patients with hyperglycaemia following stroke are ongoing. Such trials will determine if aggressive control of acute hyperglycaemia following stroke has similar benefits to that observed following acute myocardial infarction. Clinicians responsible for stroke patients should be aware of the importance of adequate glycaemic control in both primary and secondary prevention of stroke.
Denver screening protocol for blunt cerebrovascular injury reduces the use of multi-detector computed tomography angiography
Publisher: Wiley
Date: 14-11-2013
DOI: 10.1111/ANS.12439
Abstract: Blunt cerebrovascular injury (BCVI) occurs in 0.2-2.7% of blunt trauma patients and has up to 30% mortality. Conventional screening does not recognize up to 20% of BCVI patients. To improve diagnosis of BCVI, both an expanded battery of screening criteria and a multi-detector computed tomography angiography (CTA) have been suggested. The aim of this study is to investigate whether the use of CTA restricted to the Denver protocol screen-positive patients would reduce the unnecessary use of CTA as a pre-emptive screening tool. This is a registry-based study of blunt trauma patients admitted to Auckland City Hospital from 1998 to 2012. The diagnosis of BCVI was confirmed or excluded with CTA, magnetic resonance angiography and, if these imaging were non-conclusive, four-vessel digital subtraction angiography. Thirty (61%) BCVI and 19 (39%) non-BCVI patients met eligibility criteria. The Denver protocol applied to our cohort of patients had a sensitivity of 97% (95% confidence interval (CI): 83-100%) and a specificity of 42% (95% CI: 20-67%). With a prevalence of BCVI in blunt trauma patients of 0.2% and 2.7%, post-test odds of a screen-positive test were 0.03 (95% CI: 0.002-0.005) and 0.046 (95% CI: 0.314-0.068), respectively. Application of the CTA to the Denver protocol screen-positive trauma patients can decrease the use of CTA as a pre-emptive screening tool by 95-97% and reduces its hazards.
Depression and Anxiety Across the First Year After Ischemic Stroke: Findings from a Population-Based New Zealand ARCOS-IV Study
Publisher: Cambridge University Press (CUP)
Date: 29-06-2017
Abstract: Background: Depression and anxiety are the two most frequently studied emotional outcomes of stroke. However, few previous studies have been carried out at a population level or beyond 6 months post stroke. The aim of this study was to describe depression and anxiety across the first year following incident ischemic stroke (IS), and identify predictive factors in a population-based study. Method: The Hospital Anxiety Depression Scale (HADS) was administered at baseline (within 2 weeks of onset), and again at 1-month, 6-months and 12-months after IS in a s le ( N = 365) drawn from a population-based study. Results: Over 75% of those assessed experienced depression or anxiety symptoms below cut-offs for probable disorder across the year post stroke. Moderate to severe symptoms for anxiety were approximately twice as likely (range 4.1%–10.6%) as compared to depression (range 2.5%–5.0%) at each assessment. The greatest improvement in anxiety occurred within the first month post stroke. In contrast, the greatest reduction in depression occurred between 1- to 6-months post stroke. Conclusions: Anxiety symptoms in the moderate to severe range were twice as common as depression, and improved over the first month post stroke, whilst depression symptoms persisted for up to 6 months, indicating a need to target these two issues at different points in the recovery process.
Stroke reperfusion therapy following dabigatran reversal with idarucizumab in a national cohort
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 20-02-2020
DOI: 10.1212/WNL.0000000000009155
Abstract: To assess the frequency and utilization trends of dabigatran reversal with idarucizumab and compare associated complications, outcomes, and door-to-needle times to those of patients not exposed to idarucizumab in a nationwide cohort of thrombolyzed patients over a 24-month period. This is an observational cohort study of all New Zealand patients with stroke treated with stroke reperfusion entered into a mandatory online national registry. Each hospital records data including patient demographics, treatment delays, complications, 7-day outcomes, and idarucizumab use. Between 1 January 2017 and 31 December 2018, 1,336 patients received thrombolysis. Fifty-one patients received idarucizumab prior to thrombolysis (median [interquartile range] age 73 [57–83] years): 8 (1.3%) in 2017 and 43 (6%) in 2018 ( p 0.001). Over the same 24-month period, 386 patients had stroke clot retrieval, of whom 8 (2.1%) were first treated with idarucizumab. Idarucizumab-treated patients had slower door-to-needle times (83 [54–110] minutes vs 61 [43–85] minutes, p = 0.0006). Symptomatic intracerebral hemorrhage occurred in 2 (3.9%) of the idarucizumab-treated patients and 49 (3.8%) of the other thrombolyzed patients ( p = 0.97). None of the idarucizumab-treated patients had significant thrombotic complications. At 7 days, 3 (5.9%) idarucizumab-treated and 101 (7.9%) of the other thrombolyzed patients had died ( p = 0.61). Idarucizumab was used in 6% of all thrombolyzed patients in a national cohort during 2018, up from 1.3% in 2017. Idarucizumab appeared to be safe with similar clinical outcomes to routinely managed patients, despite a 22-minute door-to-needle time delay. Idarucizumab can facilitate thrombolysis in patients with stroke taking dabigatran. This study provides Class III evidence that idarucizumab use is associated with similar early post-thrombolysis outcomes compared with patients not exposed to this drug.
Echoplanar magnetic resonance imaging in acute stroke
Publisher: Elsevier BV
Date: 2000
Abstract: Echoplanar magnetic resonance imaging (EPI) enables rapid, non-invasive imaging and analysis of cerebral pathophysiology in acute stroke. It represents an important clinical advance over computed tomography (CT) and conventional magnetic resonance (MR) scanning. It can rapidly delineate infarcted cerebral tissue and distinguish acute from chronic stroke. In addition, EPI has the potential to quickly determine the presence and degree of potentially viable brain tissue in the ischaemic penumbra. Thrombolysis is thought to reperfuse the penumbra and hence reduce infarct size. The thrombolytic agent tissue plasminogen activator (t-PA) improves outcome in ischaemic stroke when administered within the first 3 hours of onset. However, there is a significant risk of haemorrhage, and the time window for benefit may well exceed 3 hours in some patients. Hence, by facilitating diagnosis of 'at-risk' tissue in the ischaemic penumbra, a major clinical role of EPI may well become the rational selection of patients for acute interventional stroke therapy.
Lateralization of motor imagery following stroke
Publisher: Elsevier BV
Date: 08-2007
DOI: 10.1016/J.CLINPH.2007.05.008
Abstract: Motor imagery may activate the primary motor cortex (M1) and promote functional recovery following stroke. We investigated whether the hemisphere affected by stroke affects performance and M1 activity during motor imagery. Twelve stroke patients (6 left, 6 right hemisphere) and eight healthy age-matched adults participated. Experiment 1 assessed the speed and ease of actual and imagined motor performance. Experiment 2 measured corticomotor excitability during imagined movement of each hand separately, and both hands together, using transcranial magnetic stimulation. For control participants, imagined movements were performed more slowly than actual movements, and right-hand MEPs were facilitated when they imagined moving their right hand or both hands together. Patients reported being able to imagine movements with either hand, despite no measurable facilitation of MEPs in the stroke-affected hand. In left hemisphere patients, MEPs were facilitated in the left hand during imagery of the right hand and both hands together. In right hemisphere patients, motor imagery did not facilitate MEPs in either hand. Motor imagery does not appear to facilitate the ipsilesional M1 following stroke. Motor imagery may play a role in rehabilitating movement planning, but its role in directly facilitating corticomotor output appears limited.
Tenecteplase versus alteplase before endovascular thrombectomy (EXTEND-IA TNK): A multicenter, randomized, controlled study
Publisher: SAGE Publications
Date: 27-09-2018
Abstract: Intravenous thrombolysis with alteplase remains standard care prior to thrombectomy for eligible patients within 4.5 h of ischemic stroke onset. However, alteplase only succeeds in reperfusing large vessel arterial occlusion prior to thrombectomy in a minority of patients. We hypothesized that tenecteplase is non-inferior to alteplase in achieving reperfusion at initial angiogram, when administered within 4.5 h of ischemic stroke onset, in patients planned to undergo endovascular therapy. EXTEND-IA TNK is an investigator-initiated, phase II, multicenter, prospective, randomized, open-label, blinded-endpoint non-inferiority study. Eligibility requires a diagnosis of ischemic stroke within 4.5 h of stroke onset, pre-stroke modified Rankin Scale≤3 (no upper age limit), large vessel occlusion (internal carotid, basilar, or middle cerebral artery) on multimodal computed tomography and absence of contraindications to intravenous thrombolysis. Patients are randomized to either IV alteplase (0.9 mg/kg, max 90 mg) or tenecteplase (0.25 mg/kg, max 25 mg) prior to thrombectomy. The primary outcome measure is reperfusion on the initial catheter angiogram, assessed as modified treatment in cerebral infarction 2 b/3 or the absence of retrievable thrombus. Secondary outcomes include modified Rankin Scale at day 90 and favorable clinical response (reduction in National Institutes of Health Stroke Scale by ≥8 points or reaching 0–1) at day 3. Safety outcomes are death and symptomatic intracerebral hemorrhage. ClinicalTrials.gov NCT02388061
Adjunctive Intra-arterial Thrombolysis in Endovascular Thrombectomy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 15-06-2021
DOI: 10.1212/WNL.0000000000012112
Abstract: To evaluate the safety and efficacy of intra-arterial thrombolysis (IAT) as an adjunct to endovascular thrombectomy (EVT) in ischemic stroke, we performed a systematic review and meta-analysis of the literature. Searches were performed using MEDLINE, Embase, and Cochrane databases for studies that compared EVT with EVT with adjunctive IAT (EVT + IAT). Safety outcomes included symptomatic intracerebral hemorrhage and mortality at 3 months. Efficacy outcomes included successful reperfusion (Thrombolysis in Cerebral Infarction score of 2b–3) and functional independence, defined as a modified Rankin Scale score of 0–2 at 3 months. Five studies were identified that compared combined EVT + IAT (IA alteplase or urokinase) with EVT only and were included in the random-effects meta-analysis. There were 1693 EVT patients, including 269 patients treated with combined EVT + IAT and 1,424 patients receiving EVT only. Pooled analysis did not demonstrate any differences between EVT + IAT and EVT only in rates of symptomatic intracerebral hemorrhage (odds ratio [OR]: 0.61, 95% confidence interval [CI]: 0.20–1.85 p = 0.78), mortality (OR: 0.77, 95% CI: 0.54–1.10 p = 0.15), or successful reperfusion (OR: 1.05, 95% CI: 0.52–2.15 p = 0.89). There was a higher rate of functional independence in patients treated with EVT + IAT, although this was not statistically significant (OR: 1.34, 95% CI: 1.00–1.80 p = 0.053). Adjunctive IAT appears to be safe. In specific situations, neurointerventionists may be justified in administering small doses of intra-arterial alteplase or urokinase as rescue therapy during EVT.
Positive Result After Reanalysis Using Baseline Diffusion-Weighted Imaging/Perfusion-Weighted Imaging Co-Registration
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2011
DOI: 10.1161/STROKEAHA.110.580464
Abstract: The Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET) was a prospective, randomized, double-blinded, placebo-controlled, phase II trial of alteplase between 3 and 6 hours after stroke onset. The primary outcome of infarct growth attenuation on MRI with alteplase in mismatch patients was negative when mismatch volumes were assessed volumetrically, without coregistration, which underestimates mismatch volumes. We hypothesized that assessing the extent of mismatch by coregistration of perfusion and diffusion MRI maps may more accurately allow the effects of alteplase vs placebo to be evaluated. Patients were classified as having mismatch if perfusion-weighted imaging ided by coregistered diffusion-weighted imaging volume ratio was .2 and total coregistered mismatch volume was ≥10 mL. The primary outcome was a comparison of infarct growth in alteplase vs placebo patients with coregistered mismatch. Of 99 patients with baseline diffusion-weighted imaging and perfusion-weighted imaging, coregistration of both images was possible in 95 patients. Coregistered mismatch was present in 93% (88/95) compared to 85% (81/95) with standard volumetric mismatch. In the coregistered mismatch patients, of whom 45 received alteplase and 43 received placebo, the primary outcome measure of geometric mean infarct growth was significantly attenuated by a ratio of 0.58 with alteplase compared to placebo (1.02 vs 1.77 95% CI, 0.33–0.99 P =0.0459). When using coregistration techniques to determine the presence of mismatch at study entry, alteplase significantly attenuated infarct growth. This highlights the necessity for a randomized, placebo-controlled, phase III clinical trial of alteplase using penumbral selection beyond 3 hours.
The TWIST Algorithm Predicts Time to Walking Independently After Stroke
Publisher: SAGE Publications
Date: 10-2017
Abstract: Background and Objective. The likelihood of regaining independent walking after stroke is of concern to patients and their families and influences hospital discharge planning. The objective of this study was to explore factors that could be combined in an algorithm for predicting whether and when a patient will walk independently after stroke. Methods. Adults with new lower limb weakness were recruited within 3 days of having a stroke. Clinical assessment, transcranial magnetic stimulation, and magnetic resonance imaging were completed 1 to 2 weeks poststroke. Classification and regression tree (CART) analysis was used to identify factors that predicted whether a patient achieved independent walking by 6 or 12 weeks, or remained dependent at 12 weeks. Results. We recruited 41 patients (24 women median age 72 years, range 43-96 years). The CART analysis results were used to create the Time to Walking Independently after STroke (TWIST) algorithm, which made accurate predictions for 95% of patients. Patients with a trunk control test score at 1 week walked independently within 6 weeks. Patients with a trunk control test score only achieved independent walking by 12 weeks if they also had hip extension strength of Medical Research Council grade 3 or more. Neurophysiological and neuroimaging measures did not predict independent walking after stroke. Conclusions. In this exploratory study, the TWIST algorithm accurately predicted whether and when an in idual patient walked independently after stroke using simple bedside measures 1 week poststroke. Further work is required to develop and validate this algorithm in a larger study.
Stroke Prevention in New Zealand: Can We Do Better?
Publisher: SAGE Publications
Date: 27-10-2013
DOI: 10.1111/IJS.12117
Abstract: There are approximately 45 000 stroke survivors in New Zealand and this number is projected to increase to 50 000 survivors, with annual costs to the health system exceeding $700 million by 2015 if no effective primary stroke prevention strategies are introduced. However, development of evidence-based stroke prevention strategies requires answering several research questions. In this article, we summarize some key research questions that are particularly pertinent to stroke prevention in New Zealand.
Primed Physical Therapy Enhances Recovery of Upper Limb Function in Chronic Stroke Patients
Publisher: SAGE Publications
Date: 15-07-2000
Abstract: Background. Recovery of upper limb function is important for regaining independence after stroke. Objective. To test the effects of priming upper limb physical therapy with intermittent theta burst stimulation (iTBS), a form of noninvasive brain stimulation. Methods. Eighteen adults with first-ever chronic monohemispheric subcortical stroke participated in this randomized, controlled, triple-blinded trial. Intervention consisted of priming with real or sham iTBS to the ipsilesional primary motor cortex immediately before 45 minutes of upper limb physical therapy, daily for 10 days. Changes in upper limb function (Action Research Arm Test [ARAT]), upper limb impairment (Fugl-Meyer Scale), and corticomotor excitability, were assessed before, during, and immediately, 1 month and 3 months after the intervention. Functional magnetic resonance images were acquired before and at one month after the intervention. Results. Improvements in ARAT were observed after the intervention period when therapy was primed with real iTBS, but not sham, and were maintained at 1 month. These improvements were not apparent halfway through the intervention, indicating a dose effect. Improvements in ARAT at 1 month were related to balancing of corticomotor excitability and an increase in ipsilesional premotor cortex activation during paretic hand grip. Conclusions. Two weeks of iTBS-primed therapy improves upper limb function at the chronic stage of stroke, for at least 1 month postintervention, whereas therapy alone may not be sufficient to alter function. This indicates a potential role for iTBS as an adjuvant to therapy delivered at the chronic stage.
The volume of lacunes
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2001
Absent middle cerebral artery flow predicts the presence and evolution of the ischemic penumbra
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-1999
Abstract: In acute ischemic stroke the pattern of a perfusion-imaging (PI) lesion larger than the diffusion-weighted imaging (DWI) lesion may be a marker of the ischemic penumbra. We hypothesized that acute middle cerebral artery (MCA) occlusion would predict the presence of presumed "penumbral" patterns (PI > DWI), ischemic core evolution, and stroke outcome. Echoplanar PI, DWI, and magnetic resonance angiography (MRA) were performed in 26 patients with MCA territory stroke. Imaging and clinical studies (Canadian Neurological Scale, Barthel Index, and Rankin Scale) were performed within 24 hours of onset and repeated at days 4 and 90. MCA flow was absent in 9 of 26 patients. This was associated with larger acute PI and DWI lesions, greater PI/DWI mismatch, early DWI lesion expansion, larger final infarct size, worse clinical outcome (p < 0.01) and provided independent prognostic information (multiple linear regression analysis, p < 0.05). Acute penumbral patterns were present in 14 of 26 patients. Most of these patients (9 of 14) had no MCA flow, whereas all nonpenumbral patients (PI < or = DWI lesion) had MCA flow (p < 0.001). Penumbral-pattern patients with absent MCA flow had greater DWI lesion expansion (p < 0.05) and worse clinical outcome (Rankin Scale score, p < 0.05). Absent MCA flow on MRA predicts the presence of a presumed penumbral pattern on acute PI and DWI and worse stroke outcome. Combined MRA, PI, and DWI can identify in idual patients at risk of ischemic core progression and the potential to respond to thrombolytic therapy beyond 3 hours.
Ethnic Differences in Access to Stroke Reperfusion Therapy in Northern New Zealand
Publisher: S. Karger AG
Date: 2020
DOI: 10.1159/000510505
Abstract: b i Background: /i /b In New Zealand, Māori and Pacific people have higher age-adjusted stroke incidence rates, younger age at first stroke, and higher mortality at 12 months than other ethnic groups. We aimed to determine if access to acute stroke reperfusion therapy with intravenous thrombolysis (IVT) or endovascular thrombectomy (EVT) is equitable among ethnic groups. b i Methods: /i /b Data were obtained from the Northern Region component of the New Zealand Stroke Registry over the 21 months between January 1, 2018 and September 30, 2019. Data recorded included demographic details, self-identified ethnicity, treatment times, and clinical outcomes. National hospital discharge coding of patients admitted with ischemic stroke and stroke unspecified was used to determine the proportion of patients treated by ethnic group. b i Results: /i /b There were 537 patients normally resident in the Northern Region who received reperfusion therapy: 281 received IVT alone, 123 received EVT after bridging IVT, and 133 received EVT alone. Of the 537 patients treated with IVT or EVT, there were 81 (15.1%) Māori, 78 (14.5%) Pacific, 57 (10.6%) Asian, and 341 (63.5%) NZ European/other ethnicity patients. There were no ethnic differences in treatment process times. When compared with NZ European/others, Māori and Pacific people were younger, and Māori had worse neurological impairment at admission. A higher proportion of Māori were treated with EVT with a trend to higher proportion treated with IVT. Day 90 modified Rankin Scale (mRS) for EVT-treated patients was similar apart from Asian patients who had worse outcome when compared with NZ European/others (mRS 3 vs. 2 i /i = 0.03). b i Conclusions: /i /b This study has shown equitable access to acute stroke reperfusion therapies and largely similar outcomes in different ethnic groups in northern New Zealand.
The Use of PWI and DWI Measures in the Design of Pro-of-Concept Stroke Trials
Publisher: Wiley
Date: 04-2004
General Anesthesia Compared With Non-GA in Endovascular Thrombectomy for Ischemic Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 18-04-2023
DOI: 10.1212/WNL.0000000000207066
Abstract: Endovascular thrombectomy (EVT) for large vessel occlusion ischemic stroke is either performed under general anesthesia (GA) or with non-GA techniques such as conscious sedation or local anesthesia alone. Previous small meta-analyses have demonstrated superior recanalization rates and improved functional recovery with GA when compared with non-GA techniques. The publication of further randomized controlled trials (RCTs) could provide updated guidance when choosing between GA and non-GA techniques. A systematic search for trials in which stroke EVT patients were randomized to GA or non-GA was performed in Medline, Embase, and the Cochrane Central Register of Controlled Trials. A systematic review and meta-analysis using a random-effects model was performed. Seven RCTs were included in the systematic review and meta-analysis. These trials included a total of 980 participants (GA, N = 487 non-GA, N = 493). GA improves recanalization by 9.0% (GA 84.6% vs non-GA 75.6% odds ratio [OR] 1.75, 95% CI 1.26–2.42, p = 0.0009), and the proportion of patients with functional recovery improves by 8.4% (GA 44.6% vs non-GA 36.2% OR 1.43, 95% CI 1.04–1.98, p = 0.03). There was no difference in hemorrhagic complications or 3-month mortality. In patients with ischemic stroke treated with EVT, GA is associated with higher recanalization rates and improved functional recovery at 3 months compared with non-GA techniques. Conversion to GA and subsequent intention-to-treat analysis will underestimate the true therapeutic benefit. GA is established as effective in improving recanalization rates in EVT (7 Class 1 studies) with a high Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) certainty rating. GA is established as effective in improving functional recovery at 3 months in EVT (5 Class 1 studies) with a moderate GRADE certainty rating. Stroke services need to develop pathways to incorporate GA as the first choice for most EVT procedures in acute ischemic stroke with a level A recommendation for recanalization and level B recommendation for functional recovery.
Comment: Spice, reversible cerebral vasoconstriction, and intracranial hemorrhage
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 28-08-2015
Spontaneous reperfusion after ischemic stroke is associated with improved outcome
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 12-1998
DOI: 10.1161/01.STR.29.12.2522
Abstract: Background and Purpose —The rationale behind thrombolytic therapy in acute ischemic stroke is penumbral salvage by rapid restoration of cerebral blood flow. The relationship, however, between early reperfusion (potentially composed of both nutritional and nonnutritional components) and outcome remains unclear. Methods —To establish the relationship between reperfusion parameters and outcome variables (Canadian Neurological Scale, Barthel Index, outcome CT scans), we used 99 Tc–hexamethylpropyleneamine oxime ( 99 Tc-HMPAO) single-photon emission CT (SPECT) to examine 41 acute ischemic stroke patients. All patients had at least 2 SPECT studies (24 with 3 studies), and none had been treated with thrombolytic or other acute investigational drugs. Results —A total of 106 studies were performed. Mean time to acute study was 9.2 hours that for subacute study was 42 hours and for outcome study was 150 days. Hypoperfusion (HP) volumes at each of the 3 time points correlated with outcome clinical state and final infarct size. Both early reperfusion (61% of patients) and nutritional reperfusion alone (56%), which is early reperfusion maintained at outcome, were associated with improvement in clinical state and better functional outcome. Early HP volume change (acute minus subacute HP volume) and total HP volume change (acute minus outcome HP volume) also correlated with clinical improvement and better outcome. Conclusions —This study establishes the benefit of spontaneous reperfusion after ischemic stroke and emphasizes the prognostic value of HP deficit volumes. 99 Tc-HMPAO SPECT may be used to screen patients and group them according to perfusion deficit in acute stroke trials, thereby decreasing patient numbers required to show drug effect.
Neurological complications of carotid revascularisation
Publisher: BMJ
Date: 21-12-2011
Abstract: Carotid endarterectomy (CEA) is an effective treatment for patients with recently symptomatic severe carotid stenosis and in selected patients with symptomatic moderate carotid stenosis. Carotid artery angioplasty and stenting (CAS) is emerging as an alternative to CEA, and randomised controlled trials suggest comparable efficacy to CEA in prevention of non-perioperative stroke. Neurovascular complications can result from both procedures, usually from thromboembolism from the operated vessel, cerebral hypoperfusion causing ischaemia and, rarely, intracerebral haemorrhage. The overall incidence of perioperative strokes complicating CEA and CAS is approximately 4% and 6%, respectively, and represents a devastating outcome that the procedure was designed to prevent. Other neurological sequelae complicating carotid revascularisation include cerebral hyperperfusion syndrome, cranial and peripheral nerve injuries, and contrast encephalopathy in patients undergoing CAS. In this review, we analyse the incidence, mechanisms and perioperative management of neurological complications for patients undergoing carotid revascularisation.
A Rapidly Adaptive Collaborative Ubiquitous Computing Environment to Allow Passive Detection of Marked Objects
Publisher: Springer Berlin Heidelberg
Date: 2004
Relationship between severity of MR perfusion deficit and DWI lesion evolution
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-06-2002
Cannabis, Ischemic Stroke, and Transient Ischemic Attack A Case-Control Study
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2013
DOI: 10.1161/STROKEAHA.113.001562
Abstract: There is a temporal relationship between cannabis use and stroke in case series and population-based studies. Consecutive stroke patients, aged 18 to 55 years, who had urine screens for cannabis were compared with a cohort of control patients admitted to hospital without cardiovascular or neurological diagnoses. One hundred sixty of 218 (73%) ischemic stroke/transient ischemic attack patients had urine drug screens (100 men mean [SD] age, 44.8 [8.7] years). Twenty-five (15.6%) patients had positive cannabis drug screens. These patients were more likely to be men (84% versus 59% χ 2 : P =0.016) and tobacco smokers (88% versus 28% χ 2 : P .001). Control urine s les were obtained from 160 patients matched for age, sex, and ethnicity. Thirteen (8.1%) control participants tested positive for cannabis. In a logistic regression analysis adjusted for age, sex, and ethnicity, cannabis use was associated with increased risk of ischemic stroke/transient ischemic attack (odds ratio, 2.30 95% confidence interval, 1.08–5.08). However after adjusting for tobacco use, an association independent of tobacco could not be confirmed (odds ratio, 1.59 95% confidence interval, 0.71–3.70). This study provides evidence of an association between a cannabis lifestyle that includes tobacco and ischemic stroke. Further research is required to clarify whether there is an association between cannabis and stroke independent of tobacco. URL: www.anzctr.org.au . Unique identifier: ACTRN12610000198022
Proportional recovery after stroke depends on corticomotor integrity
Publisher: Wiley
Date: 17-11-2015
DOI: 10.1002/ANA.24472
Abstract: For most patients, resolution of upper limb impairment during the first 6 months poststroke is 70% of the maximum possible. We sought to identify candidate mechanisms of this proportional recovery. We hypothesized that proportional resolution of upper limb impairment depends on ipsilesional corticomotor pathway function, is mirrored by proportional recovery of excitability in this pathway, and is unaffected by upper limb therapy dose. Upper limb impairment was measured in 93 patients at 2, 6, 12, and 26 weeks after first-ever ischemic stroke. Motor evoked potentials (MEPs) and motor threshold were recorded from extensor carpi radialis using transcranial magnetic stimulation, and fractional anisotropy (FA) in the posterior limbs of the internal capsules was determined with diffusion-weighted magnetic resonance imaging. Initial impairment score, presence of MEPs and FA asymmetry were the only predictors of impairment resolution, indicating a key role for corticomotor tract function. By 12 weeks, upper limb impairment resolved by 70% in patients with MEPs regardless of their initial impairment, and ipsilesional rest motor threshold also resolved by 70%. Resolution of impairment was insensitive to upper limb therapy dose. These findings indicate that upper limb impairment resolves by 70% of the maximum possible, regardless of initial impairment, but only for patients with intact corticomotor function. Impairment resolution seems to reflect spontaneous neurobiological processes that involve the ipsilesional corticomotor pathway. A better understanding of these mechanisms could lead to interventions that increase resolution of impairment above 70%.
Clinical outcomes of delayed mechanical thrombectomy: Descriptive analysis and development of a screening tool
Publisher: Wiley
Date: 15-12-2023
DOI: 10.1111/ENE.15658
Abstract: Limited data guide the selection of patients with large vessel occlusion ischaemic stroke who may benefit from referral to a distant tertiary centre for mechanical thrombectomy (MT). We aimed to characterize this population, describe clinical outcomes and develop a screening system to identify patients most likely to benfit from delayed mechanical thrombectomy (MT). We undertook a retrospective cohort analysis enrolling patients transferred from regional sites to one of two MT comprehensive stroke units with a time from non‐contrast computed tomography (NCCT) of the brain to reperfusion of 4 h or more. We describe Alberta Stroke Programme Early Computed Tomography Score (ASPECTS), National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) in our patients and compare these patients to those in extended‐time‐window trials. Lastly, we developed and validated a scoring model to help clinicians identify appropriate patients based on variables associated with poor outcomes. We included 563 patients, 46% of whom received thrombolysis the median (interquartile range [IQR]) ASPECTS was 8 (7–10) and the median (IQR) NIHSS score was 16 (11–20). The median (IQR) symptom to mechanical reperfusion time was 390 (300–580) min. Eight patients (1%) had a symptomatic haemorrhage. We achieved good clinical outcome (defined as mRS score ≤2) in 299 patients (54%). Age, diabetes, NIHSS score and ASPECTS were used to create a weighted scoring system with a validated area under the curve of 0.83 (95% confidence interval 0.74–0.92). Our study shows, in highly selected patients, that delayed MT many hours after baseline NCCT is associated with good clinical outcomes. However, older patients with diabetes, high NIHSS score and low ASPECTS may not benefit from transfer to a hub centre many hours away for MT in this model of care.
Endovascular thrombectomy for acute ischaemic stroke improves and maintains function in the very elderly: A multicentre propensity score matched analysis
Publisher: SAGE Publications
Date: 28-12-2022
DOI: 10.1177/23969873221145778
Abstract: The very elderly (⩾80 years) are under-represented in randomised endovascular thrombectomy (EVT) clinical trials for acute ischaemic stroke. Rates of independent outcome in this group are generally lower than the less-old patients but the comparisons may be biased by an imbalance of non-age related baseline characteristics, treatment related metrics and medical risk factors. We compared outcomes between very elderly (⩾80) and the less-old ( years) using retrospective data from consecutive patients receiving EVT from four comprehensive stroke centres in New Zealand and Australia. We used propensity score matching or multivariable logistic regression to account for confounders. We included 600 patients (300 in each age cohort) after propensity score matching from an initial group of 1270 patients. The median baseline National Institutes of Health Stroke Scale was 16 (11–21), with 455 (75.8%) having symptom free pre-stroke independent function, and 268 (44.7%) receiving intravenous thrombolysis. Good functional outcome (90-day modified Rankin Scale 0–2) was achieved in 282 (46.8%), with very elderly patients having less proportion of good outcome compared to the less-old (118 (39.3%) vs 163 (54.3%), p 0.01). There was no difference between the very elderly and the less-old in the proportion of patients who returned to baseline function at 90 days (56 (18.7%) vs 62 (20.7%), p = 0.54). All-cause 90-day mortality was higher in the very elderly (75 (25%) vs 49 (16.3%), p 0.01), without a difference in symptomatic haemorrhage (very elderly 11 (3.7%) vs 6 (2.0%), p = 0.33). In the multivariable logistic regression models, the very elderly were significantly associated with reduced odds of good 90-day outcome (OR 0.49, 95% CI 0.34–0.69, p 0.01) but not with return to baseline function (OR 0.85, 90% CI 0.54–1.29, p = 0.45) after adjusting for confounders. Endovascular thrombectomy can be successfully and safely performed in the very elderly. Despite an increase in all-cause 90-day mortality, selected very elderly patients are as likely as younger patients with similar baseline characteristics to return to baseline function following EVT.
Long Distance Air Ambulance Transfers for Endovascular Thrombectomy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 29-09-2023
The Spectrum Captured: A Methodological Approach to Studying Incidence and Outcomes of Traumatic Brain Injury on a Population Level
Publisher: S. Karger AG
Date: 17-12-2011
DOI: 10.1159/000334746
Abstract: i Objective: /i Drawing on the experience of conducting the Brain Injury Incidence and Outcomes New Zealand in the Community study, this article aims to identify the issues arising from the implementation of proposed guidelines for population-based studies of incidence and outcomes in traumatic brain injury (TBI). i Study Design and Setting: /i All new cases of TBI (all ages and severities) were ascertained over a 1-year period, using overlapping prospective and retrospective sources of case ascertainment in New Zealand. All eligible TBI cases were invited to participate in a comprehensive assessment at baseline and at 1-month follow-up. i Results: /i Our experience to date has revealed the feasibility of case ascertainment methods. Consultation with community health services and professionals resulted in feasible referral pathways to support the identification of TBI cases. ‘Hot pursuit’ methods of recruitment were essential to ensure complete case ascertainment for this population with few additional cases of TBI identified through cross-checks. i Conclusion: /i This review of proposed guidelines in relation to practical study methodology provides a framework for future comparable population-based epidemiological studies of TBI incidence and outcomes in developed countries.
Medication compliance in ischaemic stroke patients
Publisher: Wiley
Date: 04-2012
DOI: 10.1111/J.1445-5994.2010.02209.X
Abstract: This study aimed to assess the degree of patient compliance with medications prescribed at hospital discharge following ischaemic stroke, and concordance between self-reported medication use and general practitioner (GP) records. The Auckland City Hospital Stroke database was used to identify consecutive patients with ischaemic stroke over a three-month period. Participants were contacted and invited to participate in a telephone questionnaire that asked about current medications. GPs were also asked to list the medications their patients were taking. Fifty-one patients were approached to participate of whom 48 consented to be interviewed at 6 weeks and 47 at 6 months. At 6 weeks, 36 of 38 (95%) were compliant with aspirin, 12 of 13 (92%) dipyridamole, 8 of 9 (88%) warfarin, 36 of 41 (88%) statins, 33 of 38 (87%) antihypertensive medications, and 7 of 7 (100%) diabetes medications. At 6 months, 97% were compliant with aspirin, 100% dipyridamole, 100% warfarin, 94% statins, 91% antihypertensive medications, and 100% diabetes medications. Natural or herbal remedy use was reported by 10 of 48 (21%) at 6 weeks and 11 of 47 (23%) at 6 months. Blister packs were used by 8 of 48 (17%) at 6 weeks and 5 of 47 (11%) at 6 months. Adherence to secondary stroke prevention medication was between 87% and 100% at 6 weeks with similar findings at 6 months after discharge. We speculate that these high compliance rates may be due to one-on-one stroke nurse counselling and the use of stroke information packs, which include information about the importance of adherence to secondary prevention medication.
The TWIST Tool Predicts When Patients Will Recover Independent Walking After Stroke: An Observational Study
Publisher: SAGE Publications
Date: 18-05-2022
DOI: 10.1177/15459683221085287
Abstract: The likelihood of regaining independent walking after stroke influences rehabilitation and hospital discharge planning. This study aimed to develop and internally validate a tool to predict whether and when a patient will walk independently in the first 6 months post-stroke. Adults with stroke were recruited if they had new lower limb weakness and were unable to walk independently. Clinical assessments were completed one week post-stroke. The primary outcome was time post-stroke by which independent walking (Functional Ambulation Category score ≥ 4) was achieved. Cox hazard regression identified predictors for achieving independent walking by 4, 6, 9, 16, or 26 weeks post-stroke. The cut-off and weighting for each predictor was determined using β-coefficients. Predictors were assigned a score and summed for a final TWIST score. The probability of achieving independent walking at each time point for each TWIST score was calculated. We included 93 participants (36 women, median age 71 years). Age 80 years, knee extension strength Medical Research Council grade ≥ 3/5, and Berg Balance Test 6, 6 to 15, or ≥ 16/56, predicted independent walking and were combined to form the TWIST prediction tool. The TWIST prediction tool was at least 83% accurate for all time points. The TWIST tool combines routine bedside tests at one week post-stroke to accurately predict the probability of an in idual patient achieving independent walking by 4, 6, 9, 16, or 26 weeks post-stroke. If externally validated, the TWIST prediction tool may benefit patients and clinicians by informing rehabilitation decisions and discharge planning.
Changing attitudes to the management of ischaemic stroke between 1997 and 2004: a survey of New Zealand physicians
Publisher: Wiley
Date: 20-04-2006
DOI: 10.1111/J.1445-5994.2006.01042.X
Abstract: In 1997, a survey of New Zealand physicians' opinions on the management of stroke was carried out. Since then, there have been a number of advances in stroke therapy. We have repeated the 1997 survey to assess changes in physicians' opinions on stroke management. A questionnaire was sent to 293 physicians responsible for patients admitted with acute stroke to hospitals throughout New Zealand. It included questions on the management of acute stroke and secondary prevention and was based on the 1997 questionnaire. Responses were received from 211 physicians of whom 174 (82%) managed patients with an acute stroke. The number of respondents who thought that stroke units were efficacious has increased (57% in 1997 to 89%, P < 0.001). The use of aspirin acutely (P < 0.001) and intravenous tissue plasminogen activator (P = 0.006) has also increased. In 2004, antihypertensive therapy for secondary stroke prevention would be commenced if the blood pressure was 150/90 by 98% of respondents and 140/90 by 70% of respondents. In 2004, a statin would be commenced if the total cholesterol level was 4.0 mmol/L by 56% of respondents and 5.0 mmol/L by 91% of respondents. This survey has shown important changes in the management of ischaemic stroke over the past 7 years.
General Anesthesia Versus Conscious Sedation in Endovascular Thrombectomy for Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 26-09-2019
DOI: 10.1097/ANA.0000000000000646
Abstract: In ischemic stroke patients, studies have suggested that clinical outcomes following endovascular thrombectomy are worse after general anesthesia (GA) compared with conscious sedation (CS). Most data are from observational trials, which are prone to measure and unmeasure confounding. We performed a systematic review and meta-analysis of thrombectomy trials where patients were randomized to GA or CS, and compared efficacy and safety outcomes. The Medline, Embase, and Cochrane databases were searched for randomized controlled trials comparing GA to CS in endovascular thrombectomy. Efficacy outcomes included successful recanalization (Thrombolysis in Cerebral Infarction score of 2b to 3), and good functional outcome, defined as a modified Rankin Scale score of 0 to 2 at 3 months. Safety outcomes included intracerebral hemorrhage and 3-month mortality. Four studies were identified and included in the random effects meta-analysis. Patients treated with GA achieved a higher proportion of successful recanalization (odds ratio [OR]: 2.14, 95% confidence interval [CI]: 1.26-3.62 P =0.005) and good functional outcome (OR: 1.71, 95% CI: 1.13-2.59 P =0.01). For every 7.9 patients receiving GA, one more achieved good functional outcome compared with those receiving CS. There were no significant differences in intracerebral hemorrhage (OR: 0.61, 95% CI: 0.20-1.85 P =0.38) or 3-month mortality (OR: 0.62, 95% CI: 0.33-1.17 P =0.14) between GA and CS patients. In centers with high quality, specialized neuroanesthesia care, GA treated thrombectomy patients had superior recanalization rates and better functional outcome at 3 months than patients receiving CS.
Vertebrobasilar Artery Calcification and Outcomes in Posterior Circulation Large Vessel Occlusion Thrombectomy
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2020
DOI: 10.1161/STROKEAHA.119.027958
Abstract: Intracranial carotid artery calcification is associated with worse outcome in anterior circulation stroke patients who undergo endovascular thrombectomy. We investigated the association between vertebrobasilar artery calcification (VBAC) and outcome in patients undergoing endovascular thrombectomy for posterior circulation large vessel occlusion. Consecutive patients treated for posterior circulation large vessel occlusion from a prospective single-center registry were studied. VBAC was manually segmented on computed tomography brain scans. The associations between VBAC and VBAC volume, functional independence (90-day modified Rankin Scale score of 0–2), and 90-day mortality were assessed using propensity score–adjusted logistic regression. Sixty-four posterior circulation large vessel occlusion patients were included. Twenty-five (39.1%) patients had VBAC, and of these, the median (interquartile range) VBAC volume was 19.8 (6.65–23.4) mm 3 . VBAC was associated with reduced functional independence (OR, 0.19 [95% CI, 0.04–0.78] P =0.03) and increased mortality (OR, 9.44 [95% CI, 2.43–36.62] P =0.005). Larger VBAC volumes were a significant predictor of reduced functional independence and increased mortality. VBAC is an independent predictor of outcome in patients undergoing endovascular thrombectomy for posterior circulation large vessel occlusion. Considering the presence of VBAC might improve prognostication and shared treatment decision-making between patients, families, and physicians.
How Does Self-Reported History of Stroke Compare to Hospitalization Data in a Population-Based Survey in New Zealand?
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 11-2010
DOI: 10.1161/STROKEAHA.110.598268
Abstract: Background and Purpose— There is mixed evidence concerning the validity of self-reported history of stroke in population-based studies. We aimed to examine the validity of self-reported stroke using hospitalization with a primary diagnosis of stroke as the reference group. Methods— Self-reported history of stroke was taken from the Survey of Families, Income, and Employment (N=18 950 2004–2005) and defined as a respondent answering yes to the question, “Have you ever been told by a doctor that you have had a stroke?”. Survey of Families, Income, and Employment respondents consented to link their data to the New Zealand Health Information Service records of publically funded hospitalizations between 1990 and 2006. We calculated positive predictive value, sensitivity, and specificity of self-reported stroke against hospitalization for stroke. Results— Approximately 2% of the adult Survey of Families, Income, and Employment population reported they had been told by a doctor that they had a stroke. Only 1% had evidence of hospitalization for stroke since 1990. The sensitivity of self-reported stroke was 73% and specificity was 98%. However, the positive predictive value, people who reported having a stroke with confirmation of hospitalization for stroke, was low at 29%. Conclusions— The use of self-reported stroke will most likely overestimate the prevalence of stroke. A combination of methods is required to determine prevalence in population-based studies.
INTERACT2: a reason for optimism with spontaneous intracerebral hemorrhage?
Publisher: SAGE Publications
Date: 19-12-2014
DOI: 10.1111/IJS.12241
Abstract: The first Intensive Blood Pressure Reduction in Acute Intracerebral Hemorrhage Trial (INTERACT1) study found that early intensive BP lowering seemed to attenuate haematoma growth when compared with a more conservative guideline based policy. Clinicians were therefore waiting with anticipation for the results of INTERACT2, in which 2839 patients with spontaneous ICH and a systolic BP between 150 and 220 mmHg were randomly assigned to receive intensive antihypertensive therapy with a systolic target of mmHg within one hour, or a standard guideline recommended treatment of mmHg. INTERACT2 failed to show a significant reduction in the rate of the primary outcome of death or major disability [modified Rankin scale score (mRS) of 3–6], with early intensive BP lowering. However, in the key secondary endpoint of an ordinal analysis of the distribution of mRS scores, there was a significant favorable shift in those patients with aggressive therapy. There were also more patients who were normal or near normal (mRS of 0–1) at 90 days. Reassuringly, there were no differences in the rate of death or numbers of serious adverse events between the two groups. INTERACT2 has shown that a strategy of early and aggressive BP lowering is safe in a wide range of clinical settings, and is probably effective. The Antihypertensive Treatment of Acute Cerebral Haemorrhage (ATACH) II trial, which is using similar BP targets to INTERACT, should shed further light on the benefit of early aggressive BP lowering in patients with spontaneous ICH.
PREP2: A biomarker‐based algorithm for predicting upper limb function after stroke
Publisher: Wiley
Date: 24-10-2017
DOI: 10.1002/ACN3.488
Neuropsychological Outcome and its Predictors Across the First Year after Ischaemic Stroke
Publisher: Cambridge University Press (CUP)
Date: 30-08-2016
Abstract: Background: Neuropsychological deficits occur in over half of the stroke survivors and are associated with the reduced functioning and a decline in quality of life. However, the trajectory of recovery and predictors of neuropsychological outcomes over the first year post stroke are poorly understood. Method: Neuropsychological performance, assessed using the CNS-Vital signs, was examined at 1 month, 6 months and 12 months after ischaemic stroke (IS) in a s le drawn from a population-based study ( N = 198). Results: While mean scores across neuropsychological domains at each time-point fell in the average range, one in five in iduals produced very low-range scores for verbal memory, attention and psychomotor speed. Significant improvements were seen for executive functioning, psychomotor speed and cognitive flexibility within 6 months post stroke, but no gains were noted from 6 to 12 months. Stroke-related neurological deficits and depression at baseline significantly contributed to the prediction of neuropsychological function at 12 month follow-up. Conclusions: In a significant minority of IS survivors, focal deficits are evident in psychomotor speed, verbal memory, executive functions and attention. Significant improvements in these domains were only evident in the first 6 months post stroke. Initial stroke-related neurological deficits and concurrent depression may be the best predictors of later cognitive functioning.
Ethnic differences in stroke outcomes in Aotearoa New Zealand: A national linkage study
Publisher: SAGE Publications
Date: 24-03-2023
DOI: 10.1177/17474930231164024
Abstract: Ethnic differences in post-stroke outcomes have been largely attributed to biological and socioeconomic characteristics resulting in differential risk factor profiles and stroke subtypes, but evidence is mixed. This study assessed ethnic differences in stroke outcome and service access in New Zealand (NZ) and explored underlying causes in addition to traditional risk factors. This national cohort study used routinely collected health and social data to compare post-stroke outcomes between NZ Europeans, Māori, Pacific Peoples, and Asians, adjusting for differences in baseline characteristics, socioeconomic deprivation, and stroke characteristics. First and principal stroke public hospital admissions during November 2017 to October 2018 were included (N = 6879). Post-stroke unfavorable outcome was defined as being dead, changing residence, or becoming unemployed. In total, 5394 NZ Europeans, 762 Māori, 369 Pacific Peoples, and 354 Asians experienced a stroke during the study period. Median age was 65 years for Māori and Pacific Peoples, and 71 and 79 years for Asians and NZ Europeans, respectively. Compared with NZ Europeans, Māori were more likely to have an unfavorable outcome at all three time-points (odds ratio (OR) = 1.6 (95% confidence interval (CI) = 1.3–1.9) 1.4 (1.2–1.7) 1.4 (1.2–1.7), respectively). Māori had increased odds of death at all time-points (1.7 (1.3–2.1) 1.5 (1.2–1.9) 1.7 (1.3–2.1)), change in residence at 3 and 6 months (1.6 (1.3–2.1) 1.3 (1.1–1.7)), and unemployment at 6 and 12 months (1.5 (1.1–2.1) 1.5 (1.1–2.1)). There was evidence of differences in post-stroke secondary prevention medication by ethnicity. We found ethnic disparities in care and outcomes following stroke which were independent of traditional risk factors, suggesting they may be attributable to stroke service delivery rather than patient factors.
Glycated hemoglobin (HbA1c) and outcome following endovascular thrombectomy for ischemic stroke
Publisher: BMJ
Date: 30-05-2019
DOI: 10.1136/NEURINTSURG-2019-015023
Abstract: In ischemic stroke, increased glycated hemoglobin (HbA1c) and glucose levels are associated with worse outcome following thrombolysis, and possibly, endovascular thrombectomy. To evaluate the association between admission HbA1c and glucose levels and outcome following endovascular thrombectomy. Consecutive patients treated with endovascular thrombectomy with admission HbA1c and glucose levels were included. The primary outcome was functional independence, defined as a modified Rankin Scale score of 0–2 at 3 months. Secondary outcomes included successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b-3), early neurological improvement (reduction in National Institutes of Health Stroke Scale (NIHSS) score ≥8 points, or NIHSS score of 0–1 at 24 hours), symptomatic intracerebral hemorrhage (sICH), and mortality at 3 months. 223 patients (136 (61%) men mean±SD age 64.5±14.6) were included. The median (IQR) HbA1c and glucose were 39 (36-45) mmol/mol and 6.9 (5.8–8.4) mmol/L, respectively. Multiple logistic regression analysis demonstrated that increasing HbA1c levels (per 10 mmol/mol) were associated with reduced functional independence (OR=0.76 95% CI 0.60–0.96 p=0.02), increased sICH (OR=1.33 95% CI 1.03 to 1.71 p=0.03), and increased mortality (OR=1.26 95% CI 1.01 to 1.57 p=0.04). There were no significant associations between glucose levels and outcome measures (all p .05). HbA1c levels are an independent predictor of worse outcome following endovascular thrombectomy. The addition of HbA1c to decision-support tools for endovascular thrombectomy should be evaluated in future studies.
Perfusion Magnetic Resonance Imaging Maps in Hyperacute Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 07-2001
Abstract: Background and Purpose —In ischemic stroke, perfusion-weighted imaging (PWI) and diffusion-weighted imaging (DWI) provide important pathophysiological information. A PWI DWI mismatch pattern suggests the presence of salvageable tissue. However, improved methods for distinguishing PWI DWI mismatch tissue that is critically hypoperfused from benign oligemia are required. Methods —We investigated the usefulness of maps of relative cerebral blood flow (rCBF), volume (rCBV), and mean transit time (rMTT) to predict transition to infarction in hyperacute ( hours) stroke patients with PWI DWI mismatch patterns. Semiquantitative color-thresholded analysis was used to measure hypoperfusion volumes, including increasing color signal intensity thresholds of rMTT delay, which were compared with infarct expansion, outcome infarct size, and clinical status. Results —Acute rCBF lesion volume had the strongest correlation with final infarct size ( r =0.91, P .001) and clinical outcome ( r =0.67, P .01). There was a trend for acute rCBF DWI mismatch volume to overestimate infarct expansion between the acute and outcome study ( P =0.06). Infarct expansion was underestimated by acute rCBV DWI mismatch ( P .001). When rMTT lesions included tissue with moderately prolonged transit times (mean delay 4.3 seconds, signal intensity values 50% to 70%), infarct expansion was overestimated. In contrast, when rMTT lesions were restricted to more severely prolonged transit times (mean delay 6.1 seconds, signal intensity %), these regions progressed to infarction in all except 1 patient, but infarct expansion was underestimated ( P .001). Conclusions —The acute rCBF lesion most accurately identified tissue in the PWI DWI mismatch region at risk of infarction. Color-thresholded PWI maps show potential for use in an acute clinical setting to prospectively predict tissue outcome.
Baseline Diabetic Status and Admission Blood Glucose Were Poor Prognostic Factors in the EPITHET Trial
Publisher: S. Karger AG
Date: 05-11-2009
DOI: 10.1159/000255969
Abstract: i Background: /i Previous data have suggested that diabetes and hyperglycemia predict poor outcome following stroke. We studied the prognostic impact of diabetes and admission blood glucose in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). i Methods: /i EPITHET was a prospective randomized placebo-controlled trial of intravenous tissue plasminogen activator (tPA) in the 3- to 6-hour time window. A preexisting diagnosis of diabetes was noted and baseline serum glucose was measured. i Results: /i Intravenous tPA attenuated infarct growth in non-diabetics, but not in diabetics (p = 0.029). In the tPA treatment group, admission blood glucose was higher among patients with poor functional outcome (p = 0.002). i Conclusions: /i Diabetes and hyperglycemia attenuate the effects of tPA on infarct evolution. Future thrombolytic trials should consider randomizing patients by subgroups based on diabetic status and serum glucose levels.
Why Calls for More Routine Carotid Stenting Are Currently Inappropriate
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2013
Pretreatment Diffusion- and Perfusion-MR Lesion Volumes Have a Crucial Influence on Clinical Response to Stroke Thrombolysis
Publisher: SAGE Publications
Date: 20-01-2010
DOI: 10.1038/JCBFM.2010.3
Abstract: We hypothesized that pretreatment magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) lesion volumes may have influenced clinical response to thrombolysis in the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). In 98 patients randomized to intravenous (IV) tissue plasminogen activator (tPA) or placebo 3 to 6 h after stroke onset, we examined increasing acute DWI and PWI lesion volumes (Tmax—with 2-sec delay increments), and increasing PWI/DWI mismatch ratios, on the odds of both excellent (modified Rankin Scale (mRS): 0 to 1) and poor (mRS: 5 to 6) clinical outcome. Patients with very large PWI lesions (most had internal carotid artery occlusion) had increased odds ratio (OR) of poor outcome with IV-tPA (58% versus 25% placebo OR=4.13, P=0.032 for Tmax +2-sec volume mL). Excellent outcome from tPA treatment was substantially increased in patients with DWI lesions mL (77% versus 18% placebo, OR=15.0, P .001). Benefit from tPA was also seen with DWI lesions up to 25 mL (69% versus 29% placebo, OR=5.5, P=0.03), but not for DWI lesions mL. In contrast, increasing mismatch ratios did not influence the odds of excellent outcome with tPA. Clinical responsiveness to IV-tPA, and stroke outcome, depends more on baseline DWI and PWI lesion volumes than the extent of perfusion–diffusion mismatch.
Examining the lacunar hypothesis with diffusion and perfusion magnetic resonance Imaging
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 08-2002
DOI: 10.1161/01.STR.0000020841.74704.5B
Abstract: Background — The clinical diagnosis of subcortical cerebral infarction is inaccurate for lesion location and pathogenesis. Clinically suspected small perforating artery occlusions may be embolic infarcts, with important implications for investigation and treatment. New MRI techniques may allow more accurate determination of the stroke mechanism soon after admission. Methods — In a prospective series of 106 patients evaluated with acute diffusion-weighted MRI (DWI) and perfusion-weighted MRI (PWI) within 24 hours of stroke, we enrolled 19 with a lacunar syndrome. On the basis of the topography, DWI and PWI findings, and outcome T 2 MRI, we determined whether the mechanism of infarction was single perforating vessel occlusion or large artery embolism. Results — Thirteen patients had pure motor stroke, 2 had ataxic hemiparesis, and 4 had sensorimotor stroke. Six patients had lacunes on MRI, none with PWI lesions. Four patients had subcortical and distal cortical infarcts on DWI. Nine had solitary restricted striatocapsular infarcts. Seven of these 9 had PWI studies, 5 with PWI lesions. The presence of a PWI lesion reliably differentiated striatocapsular from lacunar infarction for solitary small subcortical infarcts ( P =0.03). Conclusion — DWI and PWI altered the final diagnosis of infarct pathogenesis from small perforating artery occlusion to large artery embolism in 13 of 19 patients presenting with lacunar syndromes. Lacunes cannot be reliably diagnosed on clinical grounds.
MAPS IN BIBLES 1500-1600 - AN ILLUSTRATED CATALOG - DELANOSMITH,C
Publisher: Oxford University Press (OUP)
Date: 1994
DOI: 10.1093/JTS/45.1.396
Therapeutic Relevance of Elevated Blood Pressure After Ischemic Stroke in the Hypertensive Rats
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 03-2020
DOI: 10.1161/HYPERTENSIONAHA.119.14219
Abstract: Over 80% of patients exhibit an acute increase in blood pressure (BP) following stroke. Current clinical guidelines make no distinction in BP management between patients with or without prior hypertension. Spontaneously hypertensive (SH) rats were preinstrumented with telemeters to record BP, intracranial pressure, and brain tissue oxygen in the predicted ischemic penumbra for 3 days before and 10 days after transient middle cerebral artery occlusion (n=8 per group) or sham (n=5). Before stroke, BP was either left untreated or chronically treated to a normotensive level (enalapril 10 mg/kg per day). Poststroke elevations in BP were either left uncontrolled, controlled (to the prestroke baseline level), or overcontrolled (to a normotensive level) via subcutaneous infusion of labetalol. Baseline values of intracranial pressure and brain tissue oxygen were similar between all groups, whereas BP was lower in treated SH rats (144±3 versus 115±5 mm Hg P .001). Following middle cerebral artery occlusion, a similar rise in BP was observed in untreated (+16±2 mm Hg P =0.005) and treated SH rats (+13±5 mm Hg P =0.021). Intervening to prevent BP from increasing after stroke did not worsen outcome. However, reducing BP below prestroke baseline levels was associated with higher intracranial pressure (days 1–3 P .001), reduced cerebral perfusion pressure (days 2–4 P .001), higher mortality, slower functional recovery and larger infarct volumes. Although treating to maintain BP at the prestroke baseline level was not detrimental, our results suggest that when setting BP targets after stroke, consideration must be given to the potential negative impact of inadvertent excessive BP lowering in subjects with undiagnosed or poorly controlled hypertension.
Ultra-Long Transfers for Endovascular Thrombectomy-Mission Impossible?: The Australia-New Zealand Experience.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 2022
DOI: 10.1161/STROKEAHA.122.040480
Abstract: Endovascular thrombectomy (EVT) access in remote areas is limited. Preliminary data suggest that long distance transfers for EVT may be beneficial however, the magnitude and best imaging strategy at the referring center remains uncertain. We hypothesized that patients transferred miles would benefit from EVT, achieving rates of functional independence (modified Rankin Scale [mRS] score of 0–2) at 3 months similar to those patients treated at the comprehensive stroke center in the randomized EVT extended window trials and that the selection of patients with computed tomography perfusion (CTP) at the referring site would be associated with ordinal shift toward better outcomes on the mRS. This is a retrospective analysis of patients transferred from 31 referring hospitals miles (measured by the most direct road distance) to 9 comprehensive stroke centers in Australia and New Zealand for EVT consideration (April 2016 through May 2021). There were 131 patients the median age was 64 [53–74] years and the median baseline National Institutes of Health Stroke Scale score was 16 [12–22]. At baseline, 79 patients (60.3%) had noncontrast CT+CT angiography, 52 (39.7%) also had CTP. At the comprehensive stroke center, 114 (87%) patients underwent cerebral angiography, and 96 (73.3%) proceeded to EVT. At 3 months, 62 patients (48.4%) had an mRS score of 0 to 2 and 81 (63.3%) mRS score of 0 to 3. CTP selection at the referring site was not associated with better ordinal scores on the mRS at 3 months (mRS median of 2 [1–3] versus 3 [1–6] in the patients selected with noncontrast CT+CT angiography, P =0.1). Nevertheless, patients selected with CTP were less likely to have an mRS score of 5 to 6 (odds ratio 0.03 [0.01–0.19] P .01). In selected patients transferred miles, there was a benefit for EVT, with outcomes similar to those treated in the comprehensive stroke center in the EVT extended window trials. Remote hospital CTP selection was not associated with ordinal mRS improvement, but was associated with fewer very poor 3-month outcomes.
Stroke thrombolysis and the third international stroke trial: Examining the totality of the evidence'
Publisher: Wiley
Date: 04-2013
Trends in Stroke Incidence in Auckland, New Zealand, During 1981 to 2003
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 10-2005
DOI: 10.1161/01.STR.0000181079.42690.BF
Abstract: Background and Purpose— Long-term trends in stroke incidence in different populations have not been well characterized, largely as a result of the complexities associated with population-based stroke surveillance. Methods— We assessed temporal trends in stroke incidence using standard diagnostic criteria and community-wide surveillance procedures in the population (≈1 million) of Auckland, New Zealand, over 12-month calendar periods in 1981–1982, 1991–1992, and 2002–2003. Age-adjusted first-ever (incident) and total (attack) rates, and temporal trends, were reported with 95% confidence intervals (CIs). Rates were analyzed by sex and major age groups. Results— From 1981 to 1982, stroke rates were stable in 1991–1992 and then declined in 2002–2003, to produce overall modest declines in standardized incidence (11% 95% CI, 1 to 19%) and attack rates (9% 95% CI, 0 to 16%) between the first and last study periods. Some favorable downward trends in vascular risk factors such as cigarette smoking were counterbalanced by increasing age and body mass index, and frequency of diabetes, in patients with stroke. Conclusions— There has been a modest decline in stroke incidence in Auckland over the last 2 decades, mainly during 1991 to 2003, in association with ergent trends in major risk factors.
Refining the perfusion-diffusion mismatch hypothesis
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 06-2005
DOI: 10.1161/01.STR.0000166181.86928.8B
Abstract: Background and Purpose— The Echoplanar Imaging Thrombolysis Evaluation Trial (EPITHET) tests the hypothesis that perfusion-weighted imaging (PWI)–diffusion-weighted imaging (DWI) mismatch predicts the response to thrombolysis. There is no accepted standardized definition of PWI-DWI mismatch. We compared common mismatch definitions in the initial 40 EPITHET patients. Methods— Raw perfusion images were used to generate maps of time to peak (TTP), mean transit time (MTT), time to peak of the impulse response (Tmax) and first moment transit time (FMT). DWI, apparent diffusion coefficient (ADC), and PWI volumes were measured with planimetric and thresholding techniques. Correlations between mismatch volume (PWI vol -DWI vol ) and DWI expansion (T2 Day 90-vol -DWI Acute-vol ) were also assessed. Results— Mean age was 68±11, time to MRI 4.5±0.7 hours, and median National Institutes of Health Stroke Scale (NIHSS) score 11 (range 4 to 23). Tmax and MTT hypoperfusion volumes were significantly lower than those calculated with TTP and FMT maps ( P .001). Mismatch ≥20% was observed in 89% (Tmax) to 92% (TTP/FMT/MTT) of patients. Application of a +4s (relative to the contralateral hemisphere) PWI threshold reduced the frequency of positive mismatch volumes (TTP 73%/FMT 68%/Tmax 54%/MTT 43%). Mismatch was not significantly different when assessed with ADC maps. Mismatch volume, calculated with all parameters and thresholds, was not significantly correlated with DWI expansion. In contrast, reperfusion was correlated inversely with infarct growth ( R =−0.51 P =0.009). Conclusions— Deconvolution and application of PWI thresholds provide more conservative estimates of tissue at risk and decrease the frequency of mismatch accordingly. The precise definition may not be critical however, because reperfusion alters tissue fate irrespective of mismatch.
Australian Clinical Guidelines for Acute Stroke Management 2007
Publisher: SAGE Publications
Date: 05-2008
Ethnicity and Functional Outcome After Stroke
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 04-2011
DOI: 10.1161/STROKEAHA.110.605139
Abstract: There is limited information on the influence of ethnicity on functional outcome after stroke. We examined functional outcomes among European New Zealanders, Māori, Pacific, and Asian people 6 months after stroke in a population-based context. This was a prospective incidence and 6-month outcomes study of all new stroke patients (excluding subarachnoid hemorrhage) that occurred over 1 year in a defined geographical area in Auckland, New Zealand, during 2002 to 2003. Ethnicity was self-defined. Outcome measures included the Frenchay Activities Index, 36-item Short Form questionnaire, independence, death, composite of death and dependence, and living situation. Functional measures were available in 1127 patients 6 months after stroke. Frenchay Activities Index scores were associated with ethnicity on both univariable and multivariable analysis, with Asian and Pacific people having worse scores. Physical Component Summary score of the 36-item Short Form was associated with ethnicity on univariable (scores for Pacific, Māori, and Asian people were higher than those for Europeans) but not multivariable analysis. Asian people were less likely to be dead compared to Europeans, and Pacific people were more likely to be dependent on others for help than Europeans. Pacific people were more likely to be dead or dependent than Europeans. Asian and Pacific people were more likely to be living at home than Europeans. Ethnicity was associated independently with functional outcomes. The association was attenuated when adjusted for stroke severity and other covariates. The direction of the relationship was not consistent between measures for in idual ethnic groups.
Pathophysiological Determinants of Worse Stroke Outcome in Atrial Fibrillation
Publisher: S. Karger AG
Date: 2010
DOI: 10.1159/000316886
Abstract: i Background: /i The reasons for worse outcome following ischemic stroke in patients with atrial fibrillation (AF) remain unclear. We aimed to elucidate the pathophysiological determinants of poorer stroke outcome in patients with AF using systematic MRI data from the Echoplanar Imaging Thrombolytic Evaluation Trial (EPITHET). i Methods: /i Comparisons of infarct size, hypoperfusion volume, infarct growth, arterial occlusion, recanalization, reperfusion, hemorrhagic transformation and stroke severity were made between patients with and without AF enrolled in the EPITHET study. i Results: /i AF was present in 42 of 101 patients. At baseline, AF patients were older (79 vs. 73 years, p = 0.02), had more severe neurological impairment (National Institutes of Health Stroke Scale score 16 vs. 11, p = 0.006), larger infarcts (29 vs. 15 ml, p = 0.04) and greater volumes of more severe hypoperfusion (T sub max /sub ≧8 s, perfusion-weighted imaging volume 70 vs. 43 ml, p = 0.01) compared to patients without AF. There were no significant differences in arterial occlusion site, infarct growth, recanalization or reperfusion. At outcome, AF patients had larger infarcts (52 vs. 16 ml, p = 0.05), more severe hemorrhagic transformation (29 vs. 5%, p = 0.002 for parenchymal hematomas), greater disability (modified Rankin Scale score 4 vs. 3, p = 0.03) and higher mortality rates (31 vs. 12%, p = 0.04). AF was an independent predictor of parenchymal hematoma (OR = 6.90, 95% CI = 1.57–30.25), but not mortality (OR = 2.56, 95% CI = 0.83–7.85). i Conclusions: /i Patients with AF have worse clinical and imaging outcomes following ischemic stroke. This study suggests that the adverse effect of AF is due to greater volumes of more severely hypoperfused tissue, leading to larger infarct size and greater risk of severe hemorrhagic transformation.
Fluid-Attenuated Inversion Recovery Hyperintensity in Acute Ischemic Stroke May Not Predict Hemorrhagic Transformation
Publisher: S. Karger AG
Date: 2011
DOI: 10.1159/000331467
Abstract: i Background: /i Fluid-attenuated inversion recovery (FLAIR) hyperintensity within an acute cerebral infarct may reflect delayed onset time and increased risk of hemorrhage after thrombolysis. Given the important implications for clinical practice, we examined the prevalence of FLAIR hyperintensity in patients 3–6 h from stroke onset and its relationship to parenchymal hematoma (PH). i Methods: /i Baseline DWI and FLAIR imaging with subsequent hemorrhage detection (ECASS criteria) were prospectively obtained in patients 3–6 h after stroke onset from the pooled EPITHET and DEFUSE trials. FLAIR hyperintensity within the region of the acute DWI lesion was rated qualitatively (dichotomized as visually obvious or subtle (i.e. only visible after careful windowing)) and quantitatively (using relative signal intensity (RSI)). The association of FLAIR hyperintensity with hemorrhage was then tested alongside established predictors (very low cerebral blood volume (VLCBV) and diffusion (DWI) lesion volume) in logistic regression analysis. i Results: /i There were 49 patients with pre-treatment FLAIR imaging (38 received tissue plasminogen activator (tPA), 5 developed PH). FLAIR hyperintensity within the region of acute DWI lesion occurred in 48/49 (98%) patients, was obvious in 18/49 (37%) and subtle in 30/49 (61%). Inter-rater agreement was 92% (ĸ = 0.82). The prevalence of obvious FLAIR hyperintensity did not differ between studies obtained in the 3–4.5 h and 4.5–6 h time periods (40% vs. 33%, p = 0.77). PH was poorly predicted by obvious FLAIR hyperintensity (sensitivity 40%, specificity 64%, positive predictive value 11%). In univariate logistic regression, VLCBV (p = 0.02) and DWI lesion volume (p = 0.03) predicted PH but FLAIR lesion volume (p = 0.87) and RSI (p = 0.11) did not. In ordinal logistic regression for hemorrhage grade adjusted for age and baseline stroke severity (NIHSS), increased VLCBV (p = 0.002) and DWI lesion volume (p = 0.003) were associated with hemorrhage but FLAIR lesion volume (p = 0.66) and RSI (p = 0.35) were not. i Conclusions: /i Visible FLAIR hyperintensity is almost universal 3–6 h after stroke onset and did not predict subsequent hemorrhage in this dataset. Our findings question the value of excluding patients with FLAIR hyperintensity from reperfusion therapies. Larger studies are required to clarify what implications FLAIR-positive lesions have for patient selection.
Adverse Cardiovascular, Cerebrovascular, and Peripheral Vascular Effects of Marijuana: What Cardiologists Need to Know
Publisher: Elsevier BV
Date: 03-2014
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Unravelling A Clot-less Link Between Atrial Fibrillation And Dementia
Start Date: 2020
End Date: 2023
Funder: Marsden Fund
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