Significance of Endolymphatic Hydrops in Ears With Unilateral Sensorineural Hearing Loss.

Objective: The purpose of this study was to investigate the existence of endolymphatic hydrops (EH) in affected and unaffected ears in patients with unilateral sensorineural hearing loss (SNHL) using contrast-enhanced magnetic resonance imaging (MRI), and to evaluate the significance of EH in various otological diseases. Study Design: Retrospective study. Setting: University hospital. Methods: One hundred eighty-two ears from 91 patients with unilateral SNHL were studied. The endolymphatic space was evaluated using 3-Tesla MRI with gadodiamide hydrate. Imaging data about the degree of EH in the cochlea and vestibule were analyzed and compared between ears with various otological diseases. Results: All affected ears with delayed endolymphatic hydrops had EH. In affected ears with definite Menie` re's disease, cochlear EH was observed in all ears and vestibular EH in 93% of ears, and these rates were significantly higher in the affected than in the unaffected ears. EH was also observed in the cochlea and vestibule in 66% and 41%, respectively, of the affected ears with idiopathic sudden SNHL; however, these percentages did not differ significantly from those in the unaffected ears (52% and 38%, respectively). Conclusion: MRI showed that a high percentage of ears affected by Menie` re's disease or delayed endolymphatic hydrops had EH. Further studies should evaluate the implications of EH in ears, especially in those with sudden SNHL, in terms of secondary or pre-existing EH.