Females versus males exhibit greater brain activation in sensorimotor regions during motor imagery after stroke

Abstract

Motor imagery (MI; the mental rehearsal of movement) activates sensorimotor regions, providing the basis for its effectiveness as an intervention for motor recovery after stroke. Yet, the impact of biological sex on MI-related brain activation after stroke is unexplored. Here, we investigated sex-related differences in MI-related brain activation after stroke and explored associations between questionnaire-based MI ability and MI-related brain activation. Thirty-four individuals with chronic stroke performed MI of a complex, upper-limb movement using their paretic arm/hand. Brain activation was captured using functional magnetic resonance imaging (fMRI). Individual differences in MI ability were also assessed prior to the scan using an established MI questionnaire. MI-related brain activation was observed across sensorimotor regions. Yet, group-level contrasts revealed greater activation in sensorimotor regions for females vs. males, while greater activation in the cerebellar and parietal regions was noted in males vs. females. Females also recruited greater ipsilesional regions vs. males. Questionnaire-based MI ability was associated with brain activation localized to occipital regions. Our findings suggest that females and males may respond differently to MI-based tasks. Further, we did not find a relationship between questionnaire-based data and activity in sensorimotor regions. This finding suggests that multiple measures of MI may be needed to assess its impact. Overall, this work informs the use of MI after stroke.