The effect of transcranial magnetic stimulation on the motor-evoked potentials of the suprahyoid muscles / 中华物理医学与康复杂志

ABSTRACT

Objective To explore the effect of theta-burst stimulation (TBS) of the motor cortex on the suprahyoid muscles and the mechanism through which the bilateral motor cortex regulates the suprahyoid muscles.Methods Continuous TBS (cTBS) was applied to the left motor cortex followed by intermittent TBS (iTBS) applied to the right motor cortex of 24 healthy subjects.The motor-evoked potentials (MEPs) of the suprahyoid muscles on both sides were recorded before the stimulation and after 15 and 30 minutes.The MEP amplitudes of the left and right suprahyoid muscles were analyzed using repeated measures analysis of variance.Results Before stimulation, the average MEP amplitudes of the left and right suprahyoid muscles were (375.29 ± 176.09) μV and (368.17 ± 149.02) μV respectively, significantly lower than the values after the stimulation.Conclusion iTBS can distinctly enhance the excitability of the right motor cortex controlling the suprahyoid muscles and reverse the inhibition caused by cTBS applied to the left motor cortex.Clarifying the effect of TBS on the excitability of the bilateral motor cortex is important for the rehabilitation of dysphagic stroke survivors.