Enhancement of motor coordination by applying high frequency repetitive TMS on the sensory cortex

The sensory function plays an important role for successful motor performance. We investigated the modulating effects of high frequency repetitive transcranial magnetic stimulation (rTMS) on sensory discrimination and motor coordination. Twenty healthy participants were assigned into two random groups; the real- and sham-rTMS group. Total of 900 rTMS pulses at a frequency of 10Hz (stimulus intensity of 90% RMT) were given over deltoid representational areas of the somatosensory cortex. Sensory discrimination ability was evaluated using two-point discrimination test. Motor coordination was measured by the latency difference between the synchronized contraction of deltoid and abductor pollicis brevis muscles before and after rTMS. The sensory discrimination was significantly increased only in the deltoid area and the difference in the latency of synchronized contraction of two muscles was significantly shortened after real-rTMS compared sham condition, which had tendency of negative correlation following real-rTMS condition. The results of this study demonstrated rTMS-induced enhancement of sensorimotor integration, which may contribute to develop effective therapeutic strategies for rehabilitation of various sensorimotor disorders in the clinical setting.