Original articleHand Function and Motor Cortical Output Poststroke: Are They Related?
Section snippets
Participants
Twenty-eight first-ever stroke survivors with unilateral hemispheric lesions resulting in impaired upper extremity and hand function participated; none had apraxia or receptive aphasia. Upper-limb impairment and function was evaluated by using 3 subscales of the Motor Assessment Scale (MAS), which collectively included 17 physical task items involving the shoulder, elbow, and hand.25 Items were scored from 0 (no muscle activity) to 4 (normal movement pattern) and summed to provide a total score
Results
All subjects tolerated the procedures well except for 1 subacute stroke survivor who reported a severe headache after TMS.
Discussion
The present study showed diminished fine-motor skill and hand function bilaterally after hemispheric stroke, which was accompanied by abnormalities in cortical excitatory and inhibitory systems. Marked interhemispheric asymmetries in MEP and silent-period characteristics distinguished subjects with subacute strokes from those with chronic strokes. Although asymmetry was also evident in chronic stroke, it was less dramatic, suggesting a shift toward normalization (symmetry) with progressive
Conclusions
TMS revealed significant abnormalities after stroke, although less severe in the chronic stage of recovery than the subacute stage. Our longitudinal data from subjects with subacute stroke confirm that abnormalities in cortical excitability lessen over time, although the rate of change is not uniform for all TMS outcomes. This may explain the emergence of unique indicators of cortical excitability identified as correlates of hand function at different stages of recovery, which may relate to the
Acknowledgments
We extend our gratitude to the Departments of Physical Medicine & Rehabilitation and Physical Therapy, St. Mary’s of the Lake Hospital, for providing space and assisting with recruitment, and we thank Margaret Henderson for assistance with data processing.
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Cited by (0)
Supported by the Heart and Stroke Foundation of Ontario (grant no. NA 4839) and the Natural Sciences and Engineering Research Council (postgraduate scholarship).
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated.