The relationship between endolymphatic hydrops in the vestibule and low-frequency air-bone gaps.

Abstract

To investigate the relationship between endolymphatic hydrops and hearing level, focusing on significant vestibular endolymphatic hydrops adjacent to the stapes footplate and low-frequency air-bone gaps. Retrospective study. The study included 1,548 ears from 775 patients who underwent magnetic resonance imaging examination in our university hospital to investigate possible endolymphatic hydrops between January 2012 and December 2015. Ears were evaluated by magnetic resonance imaging performed 4 hours after intravenous injection of a standard dose of gadodiamide hydrate and/or 24 hours after intratympanic injection of gadopentetate dimeglumine diluted eightfold. Comparison of hearing thresholds on pure-tone audiometry was performed between ears having endolymphatic hydrops adjacent to the stapes footplate and those having nonadjacent endolymphatic hydrops. Forty-one ears (22 men and 19 women, mean age 48.4 years) showed significant cochlear and vestibular endolymphatic hydrops adjacent to the stapes footplate, and 79 ears (30 men and 49 women, mean age 45.0 years) showed significant nonadjacent cochlear and vestibular endolymphatic hydrops. The average air-bone gap at 250 Hz was significantly higher in the group of ears with adjacent hydrops than in those with nonadjacent hydrops. The appearance of low-frequency air-bone gaps suggests deterioration of endolymphatic hydrops, particularly in ears with Ménière's disease, and could be a useful indicator for evaluating and treating patients with endolymphatic hydrops. 4. Laryngoscope, 128:1658-1662, 2018.