[Extratympanic electrocochleography in Ménière's disease]

Abstract

Introduction: Electrocochleography is the registration of an electrophysiological event which takes place in the cochlea after an acoustical stimulus. Most of the authors consider an increased summating potential (SP)/action potential (AP) ratio as characteristic of endolymphatic hydrops.

Methods: A longitudinal, prospective study of a unilateral Ménière's population diagnosed according to the American Academy of Otolaryngology-Head and Neck Surgery classification was carried out. A complete clinical history and bedside examination were performed, in addition to complete auditory and vestibular testing and an extratympanic electrocochleography. We selected 20 normal hearing subjects with no history of vestibular and otological pathology as a control group.

Results: Of the 100 patients included in the study, 62 were diagnosed as definite Ménière's disease, and 13 and 25 as probable and possible Ménière's disease, respectively. In the electrocochleography, 85% of all the patients had an SP/AP ratio above 0.5. A sensibility of 92%, 78% and 75% was obtained in the definite, probable and possible Ménière's disease patients respectively.

Discussion and conclusions: Electrocochleography is a useful method for diagnosing and evaluating patients with Ménière's disease syndrome. It provides information about the progression of the process and shows a significant correlation with the clinical stage.