title: Electrocochleography in Meniere's disease: recovery from adaptation of the auditory action potential.
abstract: CONCLUSIONS
  High prevalence rate of an enhanced summating potential (SP)/action potential (AP) ratio (≥0.35) is considered to result largely from the imbalances of Ca(2+) homeostasis in the endolymphatic space. An increase in Ca(2+) is thought to augment the SP. Furthermore, a greater inflow of Ca(2+) into inner hair cells is supposed to influence the disturbed release of neurotransmitter, which may induce pathological functioning of inner hair cell synapses. We speculate that such abnormal synaptic functioning is responsible for the development of abnormally increased AP recovery from adaptation (iR).
  
  
  OBJECTIVE
  This study aimed to record the AP recovery from adaptation (AP recovery) and to investigate its clinical significance in association with other electrocochleography (ECochG) findings in Meniere's disease.
  
  
  METHODS
  ECochG was performed transtympanically in 27 patients with Meniere's disease. AP recovery was measured by a paired-click stimulation paradigm as a function of interclick intervals from 5 to 100 ms.
  
  
  RESULTS
  High prevalence of SP/AP ratio was observed in 27 patients. iR, suggesting abnormal functioning of inner hair cell synapse, was in many cases combined with an enhanced SP/AP ratio.
authors: Department of Otorhinolaryngology, Hadano Red Cross Hospital, Kanagawa-ken, Japan. tohashi@vc-net.ne.jp
authors: Toru
authors: T
authors: Ohashi
authors: Hirohito
authors: H
authors: Nishino
authors: Yoko
authors: Y
authors: Arai
authors: Izumi
authors: I
authors: Koizuka
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000222:Adaptation, Physiological; D000328:Adult; D000368:Aged; D001300:Audiometry, Evoked Response; D006801:Humans; D008575:Meniere Disease / Q000175:diagnosis / Q000378:metabolism*; D008875:Middle Aged