Exercise and Executive Function in Individuals With Chronic Stroke: A Pilot Study

Background and Purpose: Emerging evidence suggests that exercise may improve cognitive function in older adults. The purpose of this pilot study was to describe changes in measures of cognition and executive function in individuals with chronic stroke following participation in aerobic and strengthening exercise. Methods: A single-group, pretest-posttest design was used. Nine individuals with chronic stroke (mean age = 63.7 +/- 9.1 years, mean time since stroke = 50.4 +/- 37.9 months) completed a 12-week program of aerobic and strengthening exercise, 3 days per week. The primary outcome measures examined executive function (Digit Span Backwards and Flanker tests). Secondary measures examined various aspects of aerobic fitness ((V) over dotO(2peak) and 6-minute walk distance) and function (Fugl-Meyer and 10-m walk speed). Results: Following the intervention, significant improvements were found in the Digit Span Backwards test (mean change = 0.56 +/- 0.9 digits; P = 0.05), Fugl-Meyer score (mean change = 3.6 +/- 5.7; P = 0.05), and Stroke Impact Scale total score (mean change = 33.8 +/- 38.5; P = 0.02). A significant correlation was found between improved aerobic capacity and improved performance on the Flanker test (r = 0.74; P = 0.02). Discussion: The results of this study indicate that a 12-week aerobic and strengthening exercise program was associated with improvements in selected measures of executive function and functional capacity in people with stroke. Limitations of this study include the small sample size and lack of a comparison group. Conclusions: This pilot study contributes to the emerging evidence that exercise improves cognition in people with stroke. These benefits indicate the need for future study with a larger group to have sufficient power to further explore these relationships.