title: Amplitude and area ratios of summating potential/action potential (SP/AP) in Meniere's disease.
abstract: CONCLUSIONS
  Our results suggest that summating potential/action potential (SP/AP) area ratio may not necessarily have higher sensitivity in the diagnosis of endolymphatic hydrops of Meniere's disease (MD) than SP/AP amplitude ratio in transtympanic electrocochleography (ECochG).
  
  
  OBJECTIVE
  Recent studies suggested that SP/AP area curve ratio was more sensitive to endolymphatic hydrops in comparison with SP/AP amplitude ratio in extratympanic ECochG. The purpose of the present study was to evaluate the utility of the SP/AP area curve ratio in transtympanic ECochG for the diagnosis of MD.
  
  
  METHODS
  A retrospective chart review of 198 patients (209 ears) was conducted in cases of MD.
  
  
  RESULTS
  With regard to SP/AP amplitude ratio, 57.1% in definite cases of MD (group 1), 39.6% in probable cases of MD (group 2), and 50.0% in the cases who had transformed from probable MD to definite MD (group 3) showed abnormally high values, respectively. Abnormally high values were observed in 43.9%, 27.7%, and 30.0% in SP/AP area ratio in groups 1, 2, and 3, respectively, indicating that abnormal values were observed more frequently in the amplitude ratio than in the area ratio in all three groups.
authors.affiliation: Department of Otolaryngology Head and Neck Surgery, Nagasaki University Graduate School of Biomedical Sciences, Sakamoto, Nagasaki, Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Baba
authors.forename: Kenji
authors.initials: K
authors.lastname: Takasaki
authors.forename: Fujinobu
authors.initials: F
authors.lastname: Tanaka
authors.forename: Naoki
authors.initials: N
authors.lastname: Tsukasaki
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Kumagami
authors.forename: Haruo
authors.initials: H
authors.lastname: Takahashi
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D001300:Audiometry, Evoked Response; D018159:Endolymphatic Hydrops / Q000175:diagnosis / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000175:diagnosis / Q000503:physiopathology*; D012016:Reference Values; D012189:Retrospective Studies; D012815:Signal Processing, Computer-Assisted