Article

Attention is frequently impaired after stroke, and its impairment is
associated with poor quality of life. Physical activity benefits attention in
healthy populations and has also been associated with recovery after brain injury. OBJECTIVE: We investigated the relationship between objectively measured
daily physical activity, attention network connectivity, and attention task
performance after stroke. We hypothesized that increased daily physical activity
would be associated with improved attention network function. METHODS:
Stroke patients (n = 62; mean age = 67 years, SD = 12.6 years) and healthy controls (n =
27; mean age = 68 years, SD = 6 years) underwent cognitive testing and 7 minutes
of functional magnetic resonance imaging in the resting-state. Patients were
tested 3 months after ischemic stroke. Physical activity was monitored with an
electronic armband worn for 7 days. Dorsal and ventral attention network function
was examined using seed-based connectivity analyses. RESULTS: Greater daily
physical activity was associated with increased interhemispheric connectivity of
the superior parietal lobule in the dorsal attention network (DAN; P < .05, false
discovery rate corrected). This relationship was not explained by stroke lesion
volume. Importantly, stronger connectivity in this region was related to faster
reaction time in 3 attention tasks, as revealed by robust linear regression. The
relationship remained after adjusting for age, gray matter volume, and white
matter hyperintensity load. CONCLUSIONS: Daily physical activity was associated
with increased resting interhemispheric connectivity of the DAN. Increased
connectivity was associated with faster attention performance, suggesting a
cognitive correlate to increased network connectivity. Attentional modulation by
physical activity represents a key focus for intervention studies.

Langue : ANGLAIS