Cochlear, But Not Vestibular, Endolymphatic Hydrops Predominantly Affects Vestibular Function in Patients With Unilateral Menière's Disease

Objective This study aimed to elucidate the role of cochlear and vestibular endolymphatic hydrops in audio-vestibular function in patients with unilateral Menière's disease (MD). Study Design Retrospective. Setting University hospital. Patients Forty-eight patients with unilateral MD with mild or significant cochlear/vestibular hydrops on gadolinium-enhanced MRI were enrolled. Main Outcome Measures Audio-vestibular function, duration and stage of MD, and their correlation with the grades of cochlear and vestibular hydrops. Results Disease duration in patients with stage 3 MD was significantly longer than that with stage 1 MD. Patients with stage 3 MD showed significant cochlear or vestibular hydrops more frequently than those with stage 1 MD. The mean hearing thresholds in patients with significant cochlear or vestibular hydrops were significantly higher than those with mild hydrops. The percentage of canal paresis in the caloric testing and the deviation angle in the stepping test in patients with significant cochlear, but not vestibular, hydrops were significantly greater than those with mild hydrops. The results of other vestibular function tests, such as video head impulse test, vestibular-evoked myogenic potentials, and questionnaires for vestibular and mental symptoms, did not differ between patients with significant and mild cochlear/vestibular hydrops. Conclusions Cochlear and vestibular hydrops gradually develop over time with the deterioration of hearing function, resulting in the progression of MD stage. Cochlear, but not vestibular, hydrops predominantly affects vestibular function in patients with MD.