Neupane Anuj Kumar, Gururaj Krithika, Sinha Sujeet Kumar
All India Institute of Speech and Hearing, Mysore 570006, India.
J Am Acad Audiol. 2018 Feb;29(2):175-186. doi: 10.3766/jaaa.16175.
Motion sickness is a complex autonomic phenomenon caused by the intersensory conflict among the balancing systems, resulting in a mismatch of signals between static physical conditions of the susceptible individual exposed to dynamic environment.
The present study was done to assess the sacculocollic reflex pathway and six semicircular canals in individuals susceptible to motion sickness.
Standard group comparison was used.
A total of 60 participants with an age range of 17-25 yr were included, where group I comprised 30 participants with motion sickness and group II comprised 30 participants without motion sickness. The Motion Sickness Susceptibility Questionnaire-Short was administered to classify the participants into groups with or without motion sickness.
The cervical vestibular-evoked myogenic potential (cVEMP) test and video head impulse test (vHIT) were administered to all participants. The Shapiro-Wilk test revealed normal distribution of the data (p > 0.05). Hence a parametric independent sample t test was done to check significant difference in cVEMP and vHIT parameters between the two groups.
The present study revealed no significant difference for cVEMP latencies and amplitude in individuals with motion sickness. However, significantly higher cVEMP asymmetry ratio was observed in individuals with motion sickness. Though the vestibulo-ocular reflex (VOR) gain values showed no significant difference between the two groups except for the right anterior left posterior plane, the asymmetry in VOR gain values revealed significant difference between the groups, suggesting asymmetry as a better parameter than absolute VOR gain values. Also, the presence of refixation saccades in 100% of the individuals with motion sickness accorded with various studies reported earlier with vestibular-related pathologies.
Presence of higher asymmetry ratio in cVEMP and vHIT test results plus refixation saccades to stabilize the gaze in vHIT can suggest some amount of vestibular anomalies in individuals with motion sickness.
晕动病是一种复杂的自主神经现象，由平衡系统之间的感觉冲突引起，导致易患个体在静态身体状况与动态环境接触时信号不匹配。
本研究旨在评估晕动病易感个体的球囊脊髓反射通路和六个半规管。
采用标准组比较。
共纳入60名年龄在17 - 25岁的参与者，其中第一组包括30名晕动病患者，第二组包括30名无晕动病患者。使用晕动病易感性简短问卷对参与者进行分类，分为有或无晕动病组。
对所有参与者进行颈前庭诱发肌源性电位（cVEMP）测试和视频头脉冲测试（vHIT）。Shapiro-Wilk检验显示数据呈正态分布（p > 0.05）。因此，进行参数独立样本t检验以检查两组之间cVEMP和vHIT参数的显著差异。
本研究显示晕动病个体的cVEMP潜伏期和振幅无显著差异。然而，晕动病个体的cVEMP不对称率显著更高。尽管除右前左后平面外，两组之间的前庭眼反射（VOR）增益值无显著差异，但VOR增益值的不对称性在两组之间显示出显著差异，表明不对称性是比绝对VOR增益值更好的参数。此外，100%的晕动病个体出现重新注视扫视，这与先前报道的各种前庭相关病理学研究一致。
cVEMP和vHIT测试结果中较高的不对称率以及vHIT中为稳定注视而出现的重新注视扫视表明，晕动病个体存在一定程度的前庭异常。
