THE INFLUENCE OF LATERALITY OF BRAIN LESION ON RECOVERY OF MUSCLE FUNCTION AFTER STROKE

Abstract

Purpose/Hypothesis: Literature has shown that people with chronic stroke can continually improve their muscle function. The ankle muscles are commonly used to demonstrate functional recovery of muscle after stroke. Previous studies have indicated that the laterality of brain lesion may affect stroke recovery. No study has, however, specifically examined the influence of laterality of brain lesion on the recovery of muscle function at the ankle. The purpose of this study was to determine how the laterality of brain lesion affects the relationship between muscle function at the ankle and time post-stroke. Number of Subjects: This study examined fifteen individuals with unilateral stroke (7 right and 8 left strokes). Subjects ranged between 6 months and 7 years post-stroke. Materials/Methods: Rate of isometric torque development (RITD) at the affected ankle muscles was assessed using an isokinetic dynamometer. Pearson correlation coefficients were used for data analysis. Results: Significant positive correlations were found between time post-stroke and RITDs of both dorsi (r = .840, p < 0.01) and plantar flexors (r = .644, p < 0.05) in people with left stroke. No significant correlation was found in people with right stroke. Conclusions: Rate of isometric torque development at the affected ankle muscles increases over time in people with left brain lesion, but not with right brain lesion. The laterality of brain lesion may affect recovery of muscle function at the ankle in people with chronic stroke. Clinical Relevance: The laterality of brain lesion may be an important predictor for outcome of muscle function in stroke rehabilitation.