Frequecny Tuning of Cervical Evoked Myogenic Potentials in Motion Sickness Individuals and Individuals Having Vestibular Migraine with Motion Sickness

Abstract

Introduction: Cervical Evoked Myogenic potential (cVEMP) is useful tool for the assessment of different vestibular pathologies. Motion sickness and Vestibualr migraine with motion sickness are two pathological group which are considered in the study. Frequency tuning of cVEMP for healthy individuals are studied in the literature where as there is limited information on frequency tuning of cVEMP in motion sickness individuals and individuals having vestibular migraine with motion sickness. Aim of the study: The study aimed to characterize the frequency tuning of cVEMP in individuals with motion sickness and individuals having vestibular migraine with motion sickness. Methods: The current study included three groups with 20 participants each. Group 1 (Healthy Individuals) Group II (Motion sickness Individuals) Group III (Individuals having vestibular migraine with motion sickness). All three groups underwent cVEMP for 500Hz, 750Hz, 1000Hz and 1500Hz. Results: Present study reported no effect of different frequencies on the latency measure but amplitude measure decreased with increase in the frequencies .when the parameters are compared between three groups, it was found that P1 N1 latency of 1500Hz was earlier in motion sickness individuals compared to other two groups and the amplitude of 500Hz was significantly reduced in motion sickness individuals and individuals having vestibular migraine with motion sickness compared to healthy individuals and amplitude of 1500Hz was significantly reduced in individuals having vestibular migraine with motion sickness when compared with other two groups and there was no significant differences in asymmetry ratio was reported across three groups. Conclusion: The study revealed no effect of frequency on latency, but amplitude decreased with an increase in frequency. It also revealed absence of frequency tuning at 500Hz in individuals with motion sickness, indicating some change in the stiffness characteristics of the saccule. These changes in the stiffness might be a probable reason for the motion sickness individuals.