Comparison of acute low-tone sensorineural hearing loss versus Meniere's disease by electrocochleography.
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.
Noguchi
Yoshihiro
Y
Department of Otolaryngology, Tokyo Medical and Dental University Graduate School, Tokyo, Japan.
Nishida
Hiroaki
H
Tokano
Hisashi
H
Kawashima
Yoshiyuki
Y
Kitamura
Ken
K
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