4 Influence of vibratory stimuli induced by transcranial stimulation on motor evoked potentials of masseter muscles

Abstract

We investigated the influence of vibratory stimuli on motor evoked potentials (MEPs) in masseter muscles using transcranial magnetic stimulation. MEPs were measured every 15 seconds for 2 minutes after application of 120Hz vibratory stimuli to the mentalis for 20 seconds in five volunteers. Latency and amplitude were measured for R-MEPs on the ipsilateral side and C-MEPs on the contralateral. After application of vibratory stimuli, the amplitude of R-MEPs decreased compared with the controls, while C-MEPs increased. A significant difference was observed between R-MEPs and C-MEPs. These findings indicate that vibratory stimuli enhance excitability in the motor cortex.