Effect of muscle fatigue in the masseter muscle on motor evoked potentials using transcranial magnetic stimulation

Abstract

We investigated the influence of masseter muscle fatigue on motor evoked potentials (MEPs) by using transcranial magnetic stimulations (TMS). The experiment was carried out with continuous or periodic voluntary contractions. The latency and amplitude of the MEPs was measured. No changes were found in the latency of the MEPs. As fatigue advanced, the amplitude of the MEPs decreased. The continuous and periodic voluntary contractions produced different decreases in the amplitude of the MEP. The results suggest that TMS is effective for observation of masseter muscle fatigue.