ORCID Profile
0000-0003-4049-2364
Current Organisation
University of Oxford
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Publisher: BMJ
Date: 03-2016
Publisher: F1000 Research Ltd
Date: 30-01-2018
DOI: 10.12688/F1000RESEARCH.12528.2
Abstract: In this paper, we use evidence from our earlier review of surgical randomised controlled trials with a placebo arm to show that blinding in trials of interventional procedures is feasible. We give ex les of ingenious strategies that have been used to simulate the active procedure and to make the placebo control indistinguishable from the active treatment. We discuss why it is important to blind of patients, assessors, and caregivers and what types of bias that may occur in interventional trials. Finally, we describe the benefits of blinding, from the obvious ones such as avoiding bias, as well as less evident benefits such as avoiding patient drop out in the control arm.
Publisher: Public Library of Science (PLoS)
Date: 14-03-2014
Publisher: BMJ
Date: 21-05-2014
DOI: 10.1136/BMJ.G3253
Publisher: Elsevier BV
Date: 2018
Publisher: SAGE Publications
Date: 05-2018
Publisher: Springer Science and Business Media LLC
Date: 09-05-2015
Publisher: Cold Spring Harbor Laboratory
Date: 15-07-2017
DOI: 10.1101/163196
Abstract: Clinical pain is difficult to study using standard Blood Oxygenation Level Dependent (BOLD) magnetic resonance imaging because it is often ongoing and, if evoked, it is associated with stimulus-correlated motion. Arterial spin labelling (ASL) offers an attractive alternative. This study used arm repositioning to evoke clinically-relevant musculoskeletal pain in patients with shoulder impingement syndrome. Fifty-five patients were scanned using a multi post-labelling delay pseudo-continuous ASL (pCASL) sequence, first with both arms along the body and then with the affected arm raised into a painful position. Twenty healthy volunteers were scanned as a control group. Arm repositioning resulted in increased perfusion in brain regions involved in sensory processing and movement integration, such as the contralateral primary motor and primary somatosensory cortex, mid- and posterior cingulate cortex, and, bilaterally, in the insular cortex/operculum, putamen, thalamus, midbrain and cerebellum. Perfusion in the thalamus, midbrain and cerebellum was larger in the patient group. Results of a post hoc analysis suggested that the observed perfusion changes were related to pain rather than arm repositioning. This study showed that ASL can be useful in research on clinical ongoing musculoskeletal pain but the technique is not sensitive enough to detect small differences in perfusion.
Publisher: Cold Spring Harbor Laboratory
Date: 03-2023
DOI: 10.1101/2023.02.27.23286245
Abstract: Monoclonal antibodies against tumour necrosis factor (TNF) markedly reduce inflammation and disease activity in rheumatoid arthritis however, the mechanisms through which they affect pain are not fully understood. The aim of this study was to investigate how monoclonal antibodies against TNF alter pain processing and to determine whether neuroimaging can be used as a marker of treatment efficacy and a predictor of treatment response. Functional magnetic resonance imaging was used to study the neural correlates of clinically-relevant pain evoked by pressing the most painful joint of the right hand and experimental pain evoked by a thermal stimulus applied to the right forearm. A flashing checkerboard was used as a control stimulus. Patients with severe rheumatoid arthritis, qualifying for the anti-TNF treatment, were scanned before the beginning of the therapy and then approximately one and six months after the first injection. TNF inhibition was associated with a marked reduction in pain ratings, inflammation, disease activity as well as depression and catastrophising scores. Effective treatment was linked with less pressure-evoked brain activation in the regions involved in the processing of the sensory aspect of pain and in the limbic structures. Baseline pressure-evoked activation in the thalamus predicted future response to treatment. There was no reduction in heat-evoked brain activation on the contrary, there was an increase in the activation in the precuneus, which is involved in interoception. There were no differences in response to the visual stimulus. TNF inhibition strongly reduces brain activation in response to clinically relevant pressure pain but not experimental heat pain and these changes reflect the decrease of nociceptive input from the periphery due to the reduction of inflammation as well as central changes in pain modulation. Neuroimaging methods have the potential to explain and predict treatment effects in inflammatory pain conditions.
Publisher: Wiley
Date: 27-01-2012
DOI: 10.1002/ART.33326
Abstract: To investigate whether structural changes are present in the cortical and subcortical gray matter of the brains of patients with rheumatoid arthritis (RA). We used two surface-based style morphometry analysis programs and a voxel-based style analysis program to compare high-resolution structural magnetic resonance imaging data obtained for 31 RA patients and 25 age- and sex-matched healthy control subjects. We observed an increase in gray matter content in the basal ganglia of RA patients, mainly in the nucleus accumbens and caudate nucleus. There were no differences in the cortical gray matter. Moreover, patients had a smaller intracranial volume. Our results suggest that RA is associated with changes in the subcortical gray matter rather than with cortical gray matter atrophy. Since the basal ganglia play an important role in motor control as well as in pain processing and in modulating behavior in response to aversive stimuli, we suggest that these changes may result from altered motor control or prolonged pain processing. The differences in brain volume may reflect either generalized atrophy or differences in brain development.
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Karolina A. Feakins.