Effect of galvanic vestibular stimulation on movement-related cortical potential

[Purpose] This study examined the effects of galvanic vestibular stimulation on motion-related cortical potential. [Subjects and Methods] Fourty healthy female adult subjects each received galvanic vestibular stimulation or sham treatment. For galvanic vestibular stimulation, the anode and cathode were applied to the right and left mastoid processes, respectively, for 10 minutes. Motion-related cortical potential was tested pre- and post-treatment. To measure motion-related cortical potential, surface electromyography signals were generated by 50 thumb abductions with electrode application on the abductor pollicis brevis of the left (i.e., non-dominant) hand. [Results] The negative slope cortical potential on the C3 area (i.e., dominant hand) and cortical negative slope and motor potential on the C4 area (i.e., non-dominant hand) showed significant interaction effects. The galvanic vestibular stimulation group showed an increased negative slope amplitude in the C3 area, and increased negative slope and motor potential amplitudes in the C4 area compared to the sham group. [Conclusion] Galvanic vestibular stimulation increases the negative slope and motor potential amplitudes of the homonymous brain cortex area, which controls hand function and motion-related cortical potential, and the negative slope amplitude of the opposite cortical area, thus activating the brain areas for hand function.