How the Somatosensory System Adapts to the Motor Change in Stroke: A Hemispheric Shift?

Previous studies found that post-stroke motor impairments are associated with damage to the lesioned corticospinal tract and a maladaptive increase in indirect contralesional motor pathways. How the somatosensory system adapts to the change in the use of motor pathways and the role of adaptive sensory feedback to the abnormal movement control of the paretic arm remains largely unknown. We hypothesize that following a unilateral stroke, there is an adaptive hemispheric shift of somatosensory processing toward the contralesional sensorimotor areas to provide sensory feedback support to the contralesional indirect motor pathways. This research could provide new insights related to somatosensory reorganization after stroke, which could enrich future hypothesis-driven therapeutic rehabilitation strategies from a sensory or sensory-motor perspective. Understanding how somatosensory information shifts may provide a target for a novel method to therapeutically prevent and mitigate the emergence and expression of upper limb motor impairments, following a stroke.