[Study on the shift of ocular vestibular evoked myogenic potentials frequency tuning of Meniere's disease]

Objective: To study the shift of oVEMP frequency tuning of unilateral Meniere's disease, by analyzing oVEMP of air-conducted tone bursts in various frequencies. Methods: From May 2016 to October 2017, 33 patients with unilateral Meniere's from Aerospace Center Hospital were tested for oVEMP in 500 Hz and 1 000 Hz air-conducted tone bursts respectively, and 20 healthy subjects(40 ears), matched for age and sex, were used as healthy control. The amplitudes of the N1-P1 wave and the frequency amplitude ratios of 500/1 000 Hz in affected ears, unaffected ears and normal ears were compared; and receiver operating characteristic curve was analyzed for frequency amplitude ratios of 500/1 000 Hz. Results: By the 500 Hz tone-burst stimulus, the provocation rates of the oVEMP were 84.9%(28/33), 93.9%(31/33) and 97.5%(39/40) in affected ears, contralateral ears and the ears of normal controls, respectively. By the stimulus of 1 000 Hz tone-burst, the provocation rates of the oVEMP were 81.8%(27/33), 87.9%(29/33) and 82.5% (33/40) in affected ears, contralateral ears and normal control ears, respectively. Amplitudes of N1-P1 waveforms in 500 Hz air-conducted tone bursts in affected ears were under normal control ears and contralateral ears. There was significant difference between affected ears and healthy control ears (P<0.05). Amplitudes of N1-P1 waveforms in contralateral ears were also significantly smaller than those in normal control ears (P<0.05). There were no significant differences in amplitudes of N1-P1 waveforms between affected ears, contralateral ears and normal control ears in 1 000 Hz tone bursts stimulus(P>0.05). Frequency amplitude ratios of 500/1 000 Hz in affected ears were significantly under contralateral and normal control ears (P<0.05). According to ROC, the frequency amplitude ratio critical value of frequency tuning was set as 1.17, the positive rate of frequency tuning shift in affected ears was 54.5%(18/33) and significantly higher than in contralateral ears(18.2%, 6/33, χ(2)=9.429, P=0.002) and normal control ears (7.5%, 3/40, χ(2)=19.530, P=0.000). In contrast, there was no significant difference in the incidence of frequency tuning shift between contralateral ears and normal ears(χ(2)=1.909, P=0.167). Conclusions: Frequency tuning oVEMP with Meniere's disease will be changed.Frequency tuning of oVEMP with Meniere's disease shifts from low frequency region to high frequency region in comparison with healthy people. Frequency amplitude ratio is helpful for diagnosis of Meniere's disease.