Effects of somatosensory stimulation on motor function in chronic cortico-subcortical strokes

Somatosensory stimulation enhances aspects of motor function in patients with chronic, predominantly subcortical infarcts. We investigated the effects of somatosensory stimulation on motor function in stroke patients with predominantly cortical involvement in the middle cerebral artery territory in a double-blind, pseudorandomized crossover trial. Motor performance was evaluated with the Jebsen-Taylor test before, after 2-hour somatosensory stimulation, and after subsequent motor training (n=11). In one experimental session, patients were submitted to median nerve stimulation (MNS) and in the other session, to control stimulation (CS). The order of the sessions was counterbalanced across patients. Improvement in performance in the Jebsen-Taylor test after somatosensory stimulation and after motor training was significantly greater in the MNS session than in the CS session. Additionally, patients who received MNS in the second session maintained the beneficial effects of training 30 days later. A single MNS session improves hand motor function in patients with chronic cortico-subcortical strokes and appears to favor consolidation of training effects. Somatosensory stimulation may be an adjuvant tool for stroke rehabilitation in patients with cortical lesions.