Repeated exposure to motor imagery enhances focal brain activation during motor imagery practice after stroke

Stroke results in motor impairments of the upper limbs, linked to altered activation in sensorimotor regions. 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 effect of repeated MI on brain activation after stroke is unexplored. In this study, thirty-three individuals with stroke (>3 months) performed MI of an upper-limb movement using their paretic arm and hand across two sessions on two different days. Brain activation was obtained via functional magnetic resonance imaging (fMRI). Group-level contrasts revealed: 1) focal brain activation in Session 2 relative to Session 1, and 2) functional localization to sensorimotor regions. Together, these findings demonstrate that MI induces changes in brain activation after only two sessions in individuals with stroke, specifically encompassing activation in sensorimotor areas. Familiarizing individuals to MI prior to its use may improve applications of MI for learning and recovery.