Dataset Information

Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study.

ABSTRACT:

Objective

The nature of changes in brain activation related to good recovery of arm function after stroke is still unclear. While the notion that this is a reflection of neuronal plasticity has gained much support, confounding by compensatory strategies cannot be ruled out. We address this issue by comparing brain activity in recovered patients 6 months after stroke with healthy controls.

Methods

We included 20 patients with upper limb paresis due to ischemic stroke and 15 controls. We measured brain activation during a finger flexion-extension task with functional MRI, and the relationship between brain activation and hand function. Patients exhibited various levels of recovery, but all were able to perform the task.

Results

Comparison between patients and controls with voxel-wise whole-brain analysis failed to reveal significant differences in brain activation. Equally, a region of interest analysis constrained to the motor network to optimize statistical power, failed to yield any differences. Finally, no significant relationship between brain activation and hand function was found in patients. Patients and controls performed scanner task equally well.

Conclusion

Brain activation and behavioral performance during finger flexion-extensions in (moderately) well recovered patients seems normal. The absence of significant differences in brain activity even in patients with a residual impairment may suggest that infarcts do not necessarily induce reorganization of motor function. While brain activity could be abnormal with higher task demands, this may also introduce performance confounds. It is thus still uncertain to what extent capacity for true neuronal repair after stroke exists.

SUBMITTER: Buma FE

PROVIDER: S-EPMC4595281 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study.

Buma Floor E FE Raemaekers Mathijs M Kwakkel Gert G Ramsey Nick F NF

PloS one 20151006 10

<h4>Objective</h4>The nature of changes in brain activation related to good recovery of arm function after stroke is still unclear. While the notion that this is a reflection of neuronal plasticity has gained much support, confounding by compensatory strategies cannot be ruled out. We address this issue by comparing brain activity in recovered patients 6 months after stroke with healthy controls.<h4>Methods</h4>We included 20 patients with upper limb paresis due to ischemic stroke and 15 control ...[more]

PMID: 26440276

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Project description:ObjectivesTo survey the reported content, frequency and duration of upper limb treatment provided by occupational and physiotherapists for people after stroke in the UK.DesignA cross-sectional online survey was used. Description and analysis of the data were based on items from the Template for Intervention Description and Replication (Who, Where, What and How much).SettingThe online survey was distributed via professional and social networks to UK-based therapists.ParticipantsRespondents were occupational or physiotherapists currently working clinically in the UK with people after stroke. Over the 6 week data collection period, 156 respondents opened the survey, and 154 completed it. Respondents comprised 85 physiotherapists and 69 occupational therapists.ResultsRespondents reported treating the upper limb a median of three times a week (range: 1 to 7) for a mean of 29 min (SD: 18). Most (n=110) stated this was supplemented by rehabilitation assistants, family and/or carers providing additional therapy a median of three times a week (range 1 to 7). Functional training was the most commonly reported treatment for people with mild and moderate upper limb deficits (>40%). There was much less consistency in treatments reported for people with severe upper limb deficits with less than 20% (n=28) reporting the same treatments.ConclusionsThis study provides a contemporaneous description of reported therapy in the UK for people with upper limb deficits after stroke and a detailed template to inform standard therapy interventions in future research. Several evidence-based therapies were reported to be used by respondents (eg, constraint induced movement therapy), but others were not (eg, mental imagery). The findings also highlight that the current reported provision of upper limb therapy is markedly less than what is likely to be effective. This underlines an urgent need to configure and fund services to empower therapists to deliver greater amounts of evidence-based treatment for people with upper limb deficits after stroke.

Project description:BACKGROUND:Aberrant functional connectivity in brain networks associated with motor impairment after stroke is well described, but little is known about the association with somatosensory impairments. AIM:The objective of this cross-sectional observational study was to investigate the relationship between brain functional connectivity and severity of somatosensory impairments in the upper limb in the acute phase post stroke. METHODS:Nineteen first-ever stroke patients underwent resting-state functional magnetic resonance imaging (rs-fMRI) and a standardized clinical somatosensory profile assessment (exteroception and higher cortical somatosensation) in the first week post stroke. Integrity of inter- and intrahemispheric (ipsilesional and contralesional) functional connectivity of the somatosensory network was assessed between patients with severe (Em-NSA< 13/32) and mild to moderate (Em-NSA> 13/32) somatosensory impairments. RESULTS:Patients with severe somatosensory impairments displayed significantly lower functional connectivity indices in terms of interhemispheric (p = 0.001) and ipsilesional intrahemispheric (p = 0.035) connectivity compared to mildly to moderately impaired patients. Significant associations were found between the perceptual threshold of touch assessment and interhemispheric (r = -0.63) and ipsilesional (r = -0.51) network indices. Additional significant associations were found between the index of interhemispheric connectivity and light touch (r = 0.55) and stereognosis (r = 0.64) evaluation. CONCLUSION:Patients with more severe somatosensory impairments have lower inter- and ipsilesional intrahemispheric connectivity of the somatosensory network. Lower connectivity indices are related to more impaired exteroception and higher cortical somatosensation. This study highlights the importance of network integrity in terms of inter- and ipsilesional intrahemispheric connectivity for somatosensory function. Further research is needed investigating the effect of therapy on the re-establishment of these networks.

Project description:ObjectiveTo investigate the effects of mirror neuron theory-based visual feedback therapy (VFT) on restoration of upper limb function of stroke patients and motor-related cortical function using functional magnetic resonance imaging (fMRI).MethodsHemiplegic stroke patients were randomly divided into two groups: a VFT group and a control (CTL) group. Sixteen patients in the VFT group received conventional rehabilitation (CR) and VFT for 8 weeks, while 15 patients in the CTL group received only CR. The Barthel Index (BI) was used to assess the activities of daily living at baseline and the 8th week of the recovery training period. The Fugl-Meyer assessment (FMA) scale, somatosensory evoked potential (SEP), and fMRI were used to evaluate the recovery effect of the training therapies. The latencies and amplitudes of N9 and N20 were measured. Before recovery training, fMRI was performed for all patients in the VFT and CTL groups. In addition, 17 patients (9 in the VFT group and 8 in the CTL group) underwent fMRI for follow-up 2 months after treatment. Qualitative data were analyzed using the χ 2 test. The independent sample t-test was used to compare normally distributed data among different groups, the paired sample t-test was used to compare data between groups, and the non-parametric test was used to comparing data without normal distribution among groups.ResultsThere were no significant differences between the VFT and CTL group in all indexes. However, after 8 weeks of recovery training, these indexes were all significantly improved (P < 0.05). As compared with the CTL group, the FMA scores, BI, and N9/N20 latencies and amplitudes of SEP in the VFT group were significantly improved (P < 0.05). Two months after recovery training, fMRI showed that the degree of activation of the bilateral central anterior gyrus, parietal lobe, and auxiliary motor areas was significantly higher in the VFT group than the CTL group (P < 0.05).ConclusionsVFT based on mirror neuron theory is an effective approach to improve upper extremity motor function and daily activity performance of stroke patients. The therapeutic mechanism promotes motor relearning by activating the mirror neuron system and motor cortex. SEP amplitudes increased only for patients who participated in visual feedback. VFT promotes sensory-motor plasticity and behavioral changes in both the motor and sensory domains.

Dataset Information

Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study.

Objective

Methods

Results

Conclusion

Publications

Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study.

Similar Datasets

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