ORCID Profile
0000-0002-3746-1041
Current Organisations
Harvard Medical School
,
University of Sydney
,
Massachusetts General Hospital
,
University of Toronto
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Publisher: Elsevier BV
Date: 11-2010
Publisher: Frontiers Media SA
Date: 18-10-2017
Publisher: Elsevier BV
Date: 11-2017
DOI: 10.1016/J.JOCN.2017.07.010
Abstract: We report the case of a 68-year-old male with right eye vision loss secondary to a compressive optic neuropathy from Waldenstrom macroglobulinaemia relapse in both cavernous sinuses. Central nervous system involvement is extremely uncommon in lymphoplasmacytic lymphoma. Known as Bing-Neel syndrome, this has not been previously reported to present simultaneously in bilateral cavernous sinuses. We discuss the pathophysiology, diagnostic and neuroradiological features of Bing-Neel syndrome. In this case, there was marked clinical and radiological response to chemotherapy. As outcomes following treatment for Waldenstrom macroglobulinaemia improve, greater awareness of its less common manifestations becomes important. Neurosurgical intervention may be indicated to obtain histological diagnosis or decompress critical structures.
Publisher: BMJ
Date: 02-2006
Publisher: BMJ
Date: 25-08-2016
Publisher: Springer Science and Business Media LLC
Date: 08-02-2012
Publisher: Elsevier BV
Date: 06-2015
DOI: 10.1016/J.JOCN.2014.11.025
Abstract: This article discusses three patients with likely Hirayama disease. They have no other significant past medical history and no personal or family history of other neurological disorders. Hirayama disease is a form of cervical myelopathy attributed to forward displacement of the posterior cervical dural sac on neck flexion with resultant cord compression and/or venous congestion. It is characterized by a pure motor focal amyotrophy in the distribution of C7, C8 and T1 spinal segmental-innervated muscles and differs from other motor neuron diseases by virtue of its ultimately non-progressive course.
Publisher: AIP
Date: 2007
DOI: 10.1063/1.2744313
Publisher: Radiological Society of North America (RSNA)
Date: 02-2008
DOI: 10.1148/RADIOL.2461062076
Abstract: To prospectively evaluate the outcome of patients with acute deep vein thrombosis (DVT) of the lower extremity treated with "lacing" of the thrombus with alteplase (recombinant tissue plasminogen activator, or rTPA). This HIPAA-compliant study was approved by the Institutional Review Board of the National Heart, Lung, and Blood Institute and was funded by the National Institutes of Health. After giving written consent, 20 patients with first-onset acute DVT were treated with direct intraclot lacing of the thrombus with alteplase (maximum daily dose, 50 mg per leg per day maximum of four treatments) and full systemic anticoagulation. Alteplase was chosen because its high fibrin affinity obviates continuous infusion of this thrombolytic agent. Ventilation-perfusion (V/Q) scans were performed for evaluation of embolic risks, and clinical and imaging examinations were supplemented with pharmacokinetic studies to enable further assessment of treatment outcomes. The 20 patients included 13 men and seven women aged 18-79 years. Antegrade blood flow was restored throughout the deep venous system in 16 patients (80%) during thrombolytic therapy, with complete resolution of symptoms in 18 patients (90%) after 6 months of anticoagulation. Pharmacokinetic studies showed rapid clearance of circulating alteplase and recovery of plasminogen activator inhibitor-1 levels within 2 hours after termination of alteplase treatment. V/Q scans revealed a 40% incidence of pulmonary embolism before treatment and a 15% incidence of asymptomatic pulmonary embolism during thrombolytic therapy. There were no cases of clinically important pulmonary embolism or serious bleeding during thrombolytic therapy. During a mean follow-up period of 3.4 years, no patient developed a postthrombotic syndrome or recurrent thromboembolism. Intraclot injection or lacing of the thrombus with a fibrin-binding thrombolytic agent such as alteplase is an alternative to continuous-infusion thrombolytic regimens and minimizes the duration of systemic exposure to thrombolytic agents.
Publisher: Elsevier BV
Date: 08-2011
Publisher: Cambridge University Press (CUP)
Date: 12-2002
DOI: 10.1258/002221502761698720
Abstract: Patients with symptomatic septal perforations require treatment, with many surgeons advocating primary treatment with an obturator if conservative measures fail. Twenty nasal Button Outcome Questionnaires were sent to patients who had undergone insertion of a septal button between 1990 and 2000 in our unit. Fourteen questionnaires were returned. This study reveals that despite a reduction in symptom score in nine patients, septal buttons are poorly tolerated by patients with only 45 per cent of obturators ultimately being in situ . In view of these findings, patients are now offered a choice between primary surgical and mechanical closure in our unit.
Publisher: Elsevier BV
Date: 05-2014
DOI: 10.1016/J.MSARD.2013.11.002
Abstract: An 82-year old male, with no significant past medical history, presented with a subacute right foot drop in the setting of a 14-month history of generalised weakness, highly-responsive to steroids. Temporal artery and vastus lateralis biopsies were normal. Vasculitic screen and inflammatory markers were normal. Lumbar puncture revealed elevated cerebrospinal fluid (CSF) protein without oligoclonal bands. Visual evoked response (VER) was normal. Magnetic resonance imaging (MRI) of his lumbar spine showed compression of exiting L5 nerve root. He had three cerebral MRI scans spaced over the 12 month period, which showed a progressive increase of T2 and fluid attenuated inversion recovery (FLAIR) hyperintense lesions consistent with active demyelinating plaques. He was treated with intravenous methylprednisolone 1g daily for three days with a weaning regimen of oral prednisolone, resulting in a full return of power and a resolution of his right foot drop. He was diagnosed with late-onset multiple sclerosis (LOMS), and was treated with monthly natalizumab. A literature review of LOMS is discussed.
Publisher: Springer Science and Business Media LLC
Date: 26-07-2023
DOI: 10.1186/S12883-023-03338-9
Abstract: Neuroprotective agents have the potential to improve the outcomes of revascularisation therapies in acute ischemic stroke patients (AIS) and in those unable to receive revascularisation. Afamelanotide, a synthetic α-melanocyte stimulating hormone analogue, is a potential novel neuroprotective agent. We set out to assess the feasibility and safety of afamelanotide for the first time in AIS patients. AIS patients within 24 h of onset, with perfusion abnormality on imaging (Tmax) and otherwise ineligible for revascularisation therapies were enrolled. Afamelanotide 16 mg implants were administered subcutaneously on Day 0 (D0, day of recruitment), D1 and repeated on D7 and D8, if not well recovered. Treatment emergent adverse events (TEAEs) and neurological assessments were recorded regularly up to D42. Magnetic resonance imaging (MRI) with FLAIR sequences were also performed on D3 and D9. Six patients (5 women, median age 81, median NIHSS 6) were recruited. Two patients received 4 doses and four patients received 2. One patient (who received 2 doses), suffered a fatal recurrent stroke on D9 due to a known complete acute internal carotid artery occlusion, assessed as unrelated to the study drug. There were no other local or major systemic TEAEs recorded. In all surviving patients, the median NIHSS improved from 6 to 2 on D7. The median Tmax volume on D0 was 23 mL which was reduced to a FLAIR volume of 10 mL on D3 and 4 mL on D9. Afamelanotide was well tolerated and safe in our small s le of AIS patients. It also appears to be associated with good recovery and radiological improvement of salvageable tissue which needs to be tested in randomized studies. NCT04962503, First posted 15/07/2021.
Publisher: Ovid Technologies (Wolters Kluwer Health)
Date: 16-04-2021
DOI: 10.1093/ONS/OPAB100
Abstract: Coaxial support is a fundamental technique utilized by neurointerventionalists to optimize distal catheter control within the intracranial circulation. Here we present a 41-yr-old woman with a previously coiled ruptured anterior communicating artery aneurysm with progressive recurrence harboring tortuous internal carotid anatomy to demonstrate the utility of coaxial support. Raymond-Roy classification of initial aneurysm coiling of class 1 resulted as class 3b over the 21 mo from initial treatment.1 The patient consented to stent-assisted coiling for retreatment of this aneurysm. Coaxial support was advanced as distally as possible in the proximal vasculature to improve catheter control, reducing dead space within which the microcatheter could move, decreasing angulations within proximal vasculature, limiting the movement of the native vessels, and providing a surface of lower friction than the endothelium. As the risk of recurrent subarachnoid hemorrhage in previously treated coiled aneurysms approaches 3%, retreatment occurs in 16.4% within 6 yr2 and in 17.4% of patients within 10 yr.3 Rerupture is slightly higher in patients who underwent coiling vs clipping, with the rerupture risk inversely proportional to the degree of aneurysm occlusion,4 further substantiating that coaxial support provides technical advantage in selected patients where additional microcatheter control is necessary for optimal occlusion. Pitfalls of this technique include vasospasm and vascular injury, which can be ameliorated by pretreatment of the circulation with vasodilators to prevent catheter-induced vasospasm. This case and model demonstration illustrates the technique of coaxial access in the stent-assisted coiling of a recurrent anterior communicating artery aneurysm and identification and management of catheter-induced vasospasm.
Publisher: BMJ
Date: 02-09-2016
DOI: 10.1136/NEURINTSURG-2015-011786.REP
Abstract: This report describes two cases of post-traumatic, high flow carotid–cavernous fistulas that demonstrated residual shunting after initial embolization with coils and Onyx, and that were successfully closed with pipeline embolization devices. Following their combined endovascular treatments, the patients experienced clinical improvement of symptoms with durable obliteration of the fistulous communications.
Publisher: Elsevier BV
Date: 07-2014
DOI: 10.1016/J.JOCN.2013.10.035
Abstract: Upper limb amyotrophy may occur as an indirect consequence of various spinal disorders, including ventral longitudinal intraspinal fluid collection, Hirayama disease and high cervical cord compression. We present patients who suffer from each of these and review the literature on the three conditions with emphasis on the pathogenesis of amyotrophy. We propose that pathology some distance from the lower cervical spinal cord may affect normal venous drainage, resulting in venous congestion and reduced perfusion pressure which, in turn, could result in anterior horn cell dysfunction in all three disorders.
Publisher: Elsevier BV
Date: 02-2009
DOI: 10.1016/J.JOCN.2007.12.010
Abstract: We report the rare entity of an inverted papilloma arising from the sphenoid sinus that we expected to be a pituitary tumour on the basis of history, examination and pre-operative investigations, especially MRI appearance. Inverted sinonasal papilloma should be considered in the differential diagnosis of pituitary macroadenoma invading the sphenoid sinus.
Publisher: Elsevier BV
Date: 11-2013
DOI: 10.1016/J.JOCN.2012.10.011
Abstract: A 73-year-old man, with a history of hypertension and left supraclavicular fossa arteriovenous malformation with multiple previous uncomplicated vessel embolisation procedures, presented with acute spastic quadriparesis and urinary retention following upper limb angiography and embolisation. There was no evidence of preceding infection or neurological disease prior to the event. Cerebrospinal fluid analysis was unremarkable. MRI of the cervical spine with a 1.5 Tesla magnet performed 13 hours from symptom onset revealed bilateral paramedian intramedullary T2-weighted signal change without gadolinium enhancement limited to the grey matter with corresponding diffusion restriction extending from C5-6 down to the mid-T1. The diagnosis of cervical spinal cord infarction (SCI) was made and the patient was given regular aspirin and atorvastatin. On follow-up at 3 months, there was modest improvement with respect to his quadriparesis and was walking unaided. An extensive literature review on the role of MRI in SCI is discussed.
Publisher: Springer Science and Business Media LLC
Date: 06-05-2009
Publisher: Wiley
Date: 07-1999
DOI: 10.1046/J.1440-1746.1999.01936.X
Abstract: We describe three cases of severe necrotizing pancreatitis, with Apache II scores of 11, 17 and 22, respectively. There was no significant pancreatic parenchymal perfusion in any of the three patients on contrast-enhanced computed tomography. All three patients were primarily treated with percutaneous drains and all three subsequently required open laparotomies. We do not recommend percutaneous drainage as a definitive therapy for severe necrotizing pancreatitis.
Publisher: The Endocrine Society
Date: 04-2009
DOI: 10.1210/JC.2008-1986
Publisher: Elsevier BV
Date: 02-2011
DOI: 10.1016/J.JOCN.2010.04.036
Abstract: Hemichorea-hemiballismus is a rare complication of nonketotic hyperglycaemia in type 2 diabetes. It is associated with contralateral striatal radiological abnormality, most typically T1 hyperintensity on MRI. We report a case of a 91 year old woman who presented in a nonketotic hyperglycaemic state with right sided hemichorea. Brain CT revealed hyperdensity of the left lentiform nucleus and MRI 15 days post presentation showed left lentiform T1 hyperintensity and enlargement. The chorea improved after control of blood glucose levels. The pathophysiology of this syndrome remains controversial. It is likely that a combination of hyerglycaemia induced basal ganglia metabolic derangement and failure of cerebral blood flow autoregulation contribute to the syndrome.
No related grants have been discovered for Anthony Kam.