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

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...

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Autores principales: Buma, Floor E., Raemaekers, Mathijs, Kwakkel, Gert, Ramsey, Nick F.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4595281/
https://www.ncbi.nlm.nih.gov/pubmed/26440276
http://dx.doi.org/10.1371/journal.pone.0139746
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author Buma, Floor E.
Raemaekers, Mathijs
Kwakkel, Gert
Ramsey, Nick F.
author_facet Buma, Floor E.
Raemaekers, Mathijs
Kwakkel, Gert
Ramsey, Nick F.
author_sort Buma, Floor E.
collection PubMed
description 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.
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spelling pubmed-45952812015-10-09 Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study Buma, Floor E. Raemaekers, Mathijs Kwakkel, Gert Ramsey, Nick F. PLoS One Research Article 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. Public Library of Science 2015-10-06 /pmc/articles/PMC4595281/ /pubmed/26440276 http://dx.doi.org/10.1371/journal.pone.0139746 Text en © 2015 Buma et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Buma, Floor E.
Raemaekers, Mathijs
Kwakkel, Gert
Ramsey, Nick F.
Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study
title Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study
title_full Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study
title_fullStr Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study
title_full_unstemmed Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study
title_short Brain Function and Upper Limb Outcome in Stroke: A Cross-Sectional fMRI Study
title_sort brain function and upper limb outcome in stroke: a cross-sectional fmri study
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4595281/
https://www.ncbi.nlm.nih.gov/pubmed/26440276
http://dx.doi.org/10.1371/journal.pone.0139746
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