The use of intraoperative electrocochleography in Meniére's surgery.
Intra-operative electrocochleography was undertaken during surgery for Meniére's disease. It was found that the electrocochleogram (ECoG) provided a stable measure which accurately reflected changes within the inner ear during surgery. During salt osmosis of the round window, a rapid change in the summating potential versus action potential ratio (SP/AP) occurred which showed when the endolymphatic hydrops (ELH) had been altered. During a modified cochleostomy procedure, the ECoG showed when the cochlear duct had been ruptured. Forty ears were monitored during endolymphatic sac surgery. Twenty-five of these ears showed stable ECochG which did not alter at any time during the procedure; however, 8 of these ears showed normal SP/AP ratios during the surgery despite having been abnormal in the week prior to surgery. The SP/AP ratio was reduced in 8 ears, increased in 3 ears and showed other changes which were probably due to unstable electrode positioning in 4 ears. It was concluded that endolymphatic sac or duct surgery altered the inner ear physiology in a significant number of ears affected by endolymphatic hydrops.
Gibson
W P
WP
Department of Surgery/Otolaryngology, University of Sydney, NSW, Australia.
D000161:Acoustic Stimulation; D001300:Audiometry, Evoked Response; D003051:Cochlea / Q000601:surgery; D003053:Cochlear Duct / Q000601:surgery; D004487:Edema / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy; D004712:Endolymphatic Sac / Q000503:physiopathology / Q000601:surgery; D005260:Female; D006311:Hearing Disorders / Q000150:complications / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D016343:Monitoring, Intraoperative; D009995:Osmosis; D012965:Sodium Chloride / Q000493:pharmacokinetics / Q000627:therapeutic use
D012965:Sodium Chloride