Hemispheric asymmetry in myelin after stroke is related to motor impairment and function

The relationships between impairment, function, arm use and underlying brain structure following stroke remain unclear. Although diffusion weighted imaging is useful in broadly assessing white matter structure, it has limited utility in identifying specific underlying neurobiological components, suc...

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Main Authors: Bimal Lakhani, Kathryn S. Hayward, Lara A. Boyd
Format: Article
Language:English
Published: Elsevier 2017-01-01
Series:NeuroImage: Clinical
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2213158217300098
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author Bimal Lakhani
Kathryn S. Hayward
Lara A. Boyd
author_facet Bimal Lakhani
Kathryn S. Hayward
Lara A. Boyd
author_sort Bimal Lakhani
collection DOAJ
description The relationships between impairment, function, arm use and underlying brain structure following stroke remain unclear. Although diffusion weighted imaging is useful in broadly assessing white matter structure, it has limited utility in identifying specific underlying neurobiological components, such as myelin. The purpose of the present study was to explore relationships between myelination and impairment, function and activity in individuals with chronic stroke. Assessments of paretic upper-extremity impairment and function were administered, and 72-hour accelerometer based activity monitoring was conducted on 19 individuals with chronic stroke. Participants completed a magnetic resonance imaging protocol that included a high resolution T1 anatomical scan and a multi-component T2 relaxation imaging scan to quantify myelin water fraction (MWF). MWF was automatically parcellated from pre- and post-central subcortical regions of interest and quantified as an asymmetry ratio (contralesional/ipsilesional). Cluster analysis was used to group more and less impaired individuals based on Fugl-Meyer upper extremity scores. A significantly higher precentral MWF asymmetry ratio was found in the more impaired group compared to the less impaired group (p < 0.001). There were no relationships between MWF asymmetry ratio and upper-limb use. Stepwise multiple linear regression identified precentral MWF asymmetry as the only variable to significantly predict impairment and motor function in the upper extremity (UE). These results suggest that asymmetric myelination in a motor specific brain area is a significant predictor of upper-extremity impairment and function in individuals with chronic stroke. As such, myelination may be utilized as a more specific marker of the neurobiological changes that predict long term impairment and recovery from stroke.
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spelling doaj.art-8345108f910247598c41b86710055b082022-12-21T19:03:16ZengElsevierNeuroImage: Clinical2213-15822017-01-0114C34435310.1016/j.nicl.2017.01.009Hemispheric asymmetry in myelin after stroke is related to motor impairment and functionBimal Lakhani0Kathryn S. Hayward1Lara A. Boyd2Department of Physical Therapy, University of British Columbia, Vancouver, BC V6T 1Z3, CanadaDepartment of Physical Therapy, University of British Columbia, Vancouver, BC V6T 1Z3, CanadaDepartment of Physical Therapy, University of British Columbia, Vancouver, BC V6T 1Z3, CanadaThe relationships between impairment, function, arm use and underlying brain structure following stroke remain unclear. Although diffusion weighted imaging is useful in broadly assessing white matter structure, it has limited utility in identifying specific underlying neurobiological components, such as myelin. The purpose of the present study was to explore relationships between myelination and impairment, function and activity in individuals with chronic stroke. Assessments of paretic upper-extremity impairment and function were administered, and 72-hour accelerometer based activity monitoring was conducted on 19 individuals with chronic stroke. Participants completed a magnetic resonance imaging protocol that included a high resolution T1 anatomical scan and a multi-component T2 relaxation imaging scan to quantify myelin water fraction (MWF). MWF was automatically parcellated from pre- and post-central subcortical regions of interest and quantified as an asymmetry ratio (contralesional/ipsilesional). Cluster analysis was used to group more and less impaired individuals based on Fugl-Meyer upper extremity scores. A significantly higher precentral MWF asymmetry ratio was found in the more impaired group compared to the less impaired group (p < 0.001). There were no relationships between MWF asymmetry ratio and upper-limb use. Stepwise multiple linear regression identified precentral MWF asymmetry as the only variable to significantly predict impairment and motor function in the upper extremity (UE). These results suggest that asymmetric myelination in a motor specific brain area is a significant predictor of upper-extremity impairment and function in individuals with chronic stroke. As such, myelination may be utilized as a more specific marker of the neurobiological changes that predict long term impairment and recovery from stroke.http://www.sciencedirect.com/science/article/pii/S2213158217300098StrokeMyelinWhite matterBiomarkersMotor controlAccelerometry
spellingShingle Bimal Lakhani
Kathryn S. Hayward
Lara A. Boyd
Hemispheric asymmetry in myelin after stroke is related to motor impairment and function
NeuroImage: Clinical
Stroke
Myelin
White matter
Biomarkers
Motor control
Accelerometry
title Hemispheric asymmetry in myelin after stroke is related to motor impairment and function
title_full Hemispheric asymmetry in myelin after stroke is related to motor impairment and function
title_fullStr Hemispheric asymmetry in myelin after stroke is related to motor impairment and function
title_full_unstemmed Hemispheric asymmetry in myelin after stroke is related to motor impairment and function
title_short Hemispheric asymmetry in myelin after stroke is related to motor impairment and function
title_sort hemispheric asymmetry in myelin after stroke is related to motor impairment and function
topic Stroke
Myelin
White matter
Biomarkers
Motor control
Accelerometry
url http://www.sciencedirect.com/science/article/pii/S2213158217300098
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AT kathrynshayward hemisphericasymmetryinmyelinafterstrokeisrelatedtomotorimpairmentandfunction
AT laraaboyd hemisphericasymmetryinmyelinafterstrokeisrelatedtomotorimpairmentandfunction