Masseteric vestibular evoked myogenic potentials findings in individuals with motion sickness susceptibility

Motion sickness (MS) is a clinical condition that causes autonomic symptoms as a result of a mismatch in sensory inputs with unusual body and environmental movements. Although the cause of MS is not clearly established, one widely accepted theory is otolith asymmetry and canal-otolith conflict. Masseteric vestibular evoked myogenic potentials (mVEMPs) are short latency inhibitory potentials recorded from the bilateral masseter muscle in response to bilateral or unilateral galvanic/acoustic stimuli. Studies have shown that mVEMP evaluates the integrity of the vestibulo-trigeminal pathway and the generator region is the saccule in common with cVEMP. Our study aimed to evaluate the function of the otolith organ and vestibulo-trigeminal pathway in people with high susceptibility to MS via mVEMP. According to the Motion Sickness Susceptibility Questionnaire-Short Form (MSSQ-SF), 21 people with 70-100% susceptibility (high susceptibility) and 20 people with 0-30% susceptibility (low susceptibility) were included in the study. Participants have normal hearing and do not have any additional disorders. All participants underwent mVEMP evaluation. There was no statistical difference in P1, N1 absolute latency, N1-P1 inter-wave latency, N1-P1 amplitude, interaural amplitude asymmetry ratios at 100 dB nHL, and mVEMP thresholds in the high and low susceptibility groups. Our study obtained no findings suggesting saccule and vestibulo-trigeminal involvement in people high susceptible to motion sickness.