[Study of ocular vestibular evoked myogenic potentials in benign paroxysmal positional vertigo associated with Meniere's disease].

The aim of this study is to explore the characteristics of ocular muscle vestibular evoked myogenic potential （oVEMP） in patients with Meniere's disease and benign paroxysmal positional vertigo （BPPV-MD）, and to explore the clinical characteristics of oVEMP frequency amplitude ratio （FAR）. Forty-one patients with unilateral MD diagnosed in the outpatient clinic from January 2016 to April 2019 were selected, of which 15 patients with BPPV-MD were set as BPPV-MD group, and 26 patients with unilateral MD were set as MD group. During the same period, 30 healthy volunteers matched in age and gender were selected as the control group. All the individuals underwent oVEMP and cVEMP recording for 500 Hz and 1000 Hz tone burst. The oVEMP and cVEMP response rate, N1 and P1 waves latency, N1-P1 wave amplitude and 1000/500 Hz FAR of the affected and contralateral ears of the three groups were compared and analyzed by SPSS 20.0 software. The receiver operating characteristics curves were obtained for finding out the criterion point, sensitivity, and specificity of 1000/500 Hz FAR for the diagnosis of BPPV-MD. In response to 500 Hz tone burst, oVEMP response rates in the affected lateral ears of BPPV-MD group, MD group and right ears of control group were 46.67%, 46.15% and 76.67%, respectively; the rates for the 1000 Hz-oVEMP of the three groups were 53.33%, 46.15% and 63.33%, respectively. By the 500 Hz air-conducted tone-burst stimulus, the oVEMP N1 and P1 latency of the affected ears in the BPPV-MD group was longer than that in the MD group and the control group（<0.05）. By the stimulus of 1000 Hz tone burst, the oVEMP N1 and P1 latency of the affected ears in BPPV-MD group and MD group was longer than that in control group（<0.05）. At 500 Hz, the oVEMP amplitude of the affected ears in BPPV-MD group and MD group was lower than that in the right ears of the control group（<0.05）. There was no statistically significant difference in the N1-P1 amplitudes of oVEMP in the three groups under the stimulation of 1000 Hz tone burst（>0.05）. The FAR for 1000/500 Hz of the affected ears in BPPV-MD group and MD group was higher than that in control group（<0.05）, but there was no significant difference between BPPV-MD group and MD group（>0.05）. When FAR is greater than 0.84, which indicates that the pathophysiologic factor is accumulation of excessive amounts of endolymph; when FAR is greater than 1.79, which suggests that the otolitic membrane of the elliptic cyst is damaged by the hydrops of the labyrinthus. The FAR of BPPV-MD can be used as one of the indicators to evaluate the function of the utricle.