Search

Background: A functional vestibular system is a prerequisite for motion sickness (MS) to occur. The otolithic organs (saccule and utricle) are currently considered to be important in the pathogenesis of MS. Recent investigations have demonstrated that the ocular vestibular evoked myogenic potentials (oVEMP) test is an objective evaluation of utricular function. To date, there is no functional guide that can serve as a diagnostic tool for individual susceptibility to MS. Therefore, we investigated the link between oVEMP and MS susceptibility. Method: The oVEMP test was performed on 31 MS susceptible and 23 nonsusceptible individuals. MS susceptibility was determined by self-declaration and by using the MS susceptibility questionnaire (MSSQ) and the Hamilton Anxiety Scale (HAS). Results: Bilateral oVEMP responses were obtained in all subjects. HAS and MSSQ scores between the susceptible and nonsusceptible group were 18.27 ± 5.23 vs. 2.34 ± 1.21 and 28.12 ± 6.53 vs. 2.34 ± 1.45, respectively. Statistically significant differences in MSSQ and HAS scores were found between the MS susceptible and nonsusceptible groups. No differences were found between MS susceptible and nonsusceptible subjects in N10 and P15 wave latencies, N10-P15 interval, or peak-to-peak N10-P15 amplitude. However, there was a trend toward greater asymmetry ratio in the MS susceptible group than in the MS nonsusceptible group (18.55 ± 10.24% vs. 13.25 ± 9.47%), although statistical significance was not reached. Discussion: It appears that no relation exists between oVEMP results and MS susceptibility. Nevertheless, the differences in the asymmetry ratios of oVEMP interpeak amplitude between the two groups revealed a trend toward marginal statistical significance. [ABSTRACT FROM AUTHOR]

Introduction: Excellent vestibular function (including utricular function) is important for pilots to maintain correct spatial orientation during flight. Vestibular-evoked myogenic potential (VEMP) recorded from extraocular muscles, the so-called ocular VEMP (oVEMP), can be used to evaluate utricular function. However, oVEMP has not been applied to pilots because of lack of reliable normative data. Hence, this study is designed to establish preliminary normative data for oVEMP induced by air-conducted sound in pilots and student pilots. Methods: There were 62 healthy student pilots (30 male and 32 age-matched female) and 31 healthy male fighter pilots who were recruited as study participants. During binaural air-conducted sound stimulation oVEMP was recorded bilaterally. The latencies of nI and pI, nI-pI interval, peak-to-peak nI-pI amplitude, and asymmetry ratio (AR) of oVEMP in all participants were collected. Meanwhile, the effects of gender and age on oVEMP were also investigated. Results: The latencies of nI and pI, nI-pI interval, nI-pI interpeak amplitude, and AR of oVEMP in all participants were 10.35 ± 0.66 ms, 15.18 ± 1.07 ms, 4.75 ± 0.99 ms, 6.75 ± 4.13 μV, and 13.22 ± 9.13%, respectively. No significant difference existed between male student pilots and male pilots in terms of oVEMP parameters. The only significant difference was the nI-pI amplitude between age-matched male and female student pilots: 6.96 ± 3.85 μV for male student pilots and 5.47 ± 3.10 μV for female student pilots. Conclusions: oVEMP should be interpreted with the AR rather than raw amplitude itself. Each institution should determine its own normal values. [ABSTRACT FROM AUTHOR]