The Influence of Hand Dominance on the Response to a Constraint-Induced Therapy Program Following Stroke

Background. Following stroke it is common to exhibit deficits in mobility of the upper extremity. Constraint-induced therapy (CIT) is a rehabilitation technique used to promote use of the more affected hand via constraint of the less affected hand. One factor that could impact the outcome following CIT is hand dominance. Years of preferred use of one hand may give individuals with the dominant hand affected by stroke an advantage in improving the mobility of the more affected hand compared to those individuals with the nondominant hand affected by stroke. In addition, the diminished use of the less affected hand during CIT may also create changes. Objective. Our goal was to better understand how hand dominance may influence the response to a CIT program both cortically and behaviorally in both the more affected hand and less affected constrained hand. Methods. A repeated measures design with a double baseline was used to assess changes in clinical tests and functional magnetic resonance imaging (fMRI) in individuals with their dominant or nondominant hand affected by stroke involved in a CIT program. Results. No significant differences were found between groups in their responses to CIT. Overall subjects demonstrated behavioral and cortical changes with the more affected hand and the less affected constrained hand did not significantly change. Conclusion. CIT promotes improvement of the more affected hand particularly on complex tests without decrements to the less affected constrained hand. Cortically, statistically significant changes in activation were noted after the intervention for the more affected hand; no changes were noted with the less affected constrained hand.