Abstract
Response to motor imagery (MI) for recovery after stroke is varied; in part because we lack knowledge related to how sensorimotor processes underlying MI are altered after stroke. This work examines impact of stroke-related factors, including imagery ability, on sensorimotor processes underlying MI in individuals after (>6 months) middle cerebral artery stroke with upper-limb impairment. First, using functional magnetic resonance imaging, we evaluated brain activity across sensorimotor regions during MI. Ipsilesional primary motor cortex (iM1) was recruited for both left and right hemisphere stroke. However, when testing the association between MI-related brain activity and imagery ability, greater imagery ability was associated with recruitment of iM1 and supplementary motor area for individuals with right hemisphere stroke. While additional analyses will test intrahemispheric connectivity related to iM1 to further inform its role during MI after stroke, the above findings underscore the importance of evaluating imagery ability prior to the use of MI for stroke recovery. Taken alongside evidence suggesting MI can influence neural drive in health, we speculate that the extent to which neural drive is facilitated after stroke depends on one’s ability to perform MI; an idea being tested in ongoing work. Here, neural drive (indexed via intermuscular coherence) is evaluated before and after MI of a force steadiness task. We expect that neural drive will be altered after stroke, yet increases in neural drive facilitated via MI will be modulated by imagery ability. Overall, this work represents a key step towards the effective application of MI after stroke.
