Physical Activity After Stroke Is Associated With Increased Interhemispheric Connectivity of the Dorsal Attention Network.
BACKGROUND
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.
['Veldsman|Michele|M|', 'Churilov|Leonid|L|', 'Werden|Emilio|E|', 'Li|Qi|Q|', 'Cumming|Toby|T|', 'Brodtmann|Amy|A|']
D056044:Actigraphy D000367:Age Factors D000368:Aged D001288:Attention D001921:Brain D001931:Brain Mapping D015444:Exercise D005260:Female D006801:Humans D016014:Linear Models D008279:Magnetic Resonance Imaging D008297:Male D008875:Middle Aged D018670:Monitoring, Ambulatory D009434:Neural Pathways D009483:Neuropsychological Tests D009929:Organ Size D012146:Rest D020521:Stroke D000071939:Stroke Rehabilitation
physical activity stroke attention cognition fMRI