The effect of long-term TENS on persistent neuroplastic changes in the human cerebral cortex.

The long-term effect of daily somatosensory stimulation with transcutaneous electrical nerve stimulation (TENS) on reorganization of the motor cortex was investigated in a group of neurologically intact humans. The scalp representation of the corticospinal projection to the finger (APB, ADM) and forearm (FCR, ECR) muscles was mapped by means of transcranial magnetic stimulation (TMS) before and after a 3-week intervention period, using map area and volume, and topographical overlaps between the cortical motor representations of these muscles as primary dependent measures. Findings revealed a significant increase in cortical motor representation of all four muscles for the TENS group from pre to posttest (all, P ≤ 0.026). No significant changes in cortical motor representations were observed in the control group. The present observations highlight the potential benefit of sensory training by means of TENS as a useful complementary therapy in neurorehabilitation.