title: Comparison of acute low-tone sensorineural hearing loss versus Meniere's disease by electrocochleography.
abstract: To clarify the pathogenesis of acute low-tone sensorineural hearing loss (ALHL), we retrospectively compared the electrocochleographic findings from 20 patients with ALHL with those from 58 patients with Meniere's disease (MD) classified into 4 groups (MD1 through MD4) according to their pure tone average. The mean summating potential-action potential ratio in the ALHL group was 0.35 +/- 0.13, which was significantly higher than the control ratio but similar to the ratio seen in the MD1 group (pure tone average < 25 dB hearing level). The mean detection threshold of the cochlear microphonics in the ALHL group was 32.0 +/- 9.4 dB normal hearing level, which was again similar to that seen in the MDI group. Moreover, more than 50% of patients with ALHL had normal cochlear microphonics input-output curves. We therefore conclude that the pathogenesis of ALHL arises from an endolymphatic hydrops with little or no impairment of hair cells that resembles early-stage MD.
authors.affiliation: Department of Otolaryngology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Noguchi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nishida
authors.forename: Hisashi
authors.initials: H
authors.lastname: Tokano
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Kawashima
authors.forename: Ken
authors.initials: K
authors.lastname: Kitamura
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000208:Acute Disease; D000328:Adult; D001300:Audiometry, Evoked Response; D001301:Audiometry, Pure-Tone; D016022:Case-Control Studies; D018159:Endolymphatic Hydrops / Q000150:complications / Q000503:physiopathology; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000503:physiopathology*; D008875:Middle Aged; D012189:Retrospective Studies