title: Prognosis of low-tone sudden deafness - does it inevitably progress to Meniere's disease?
abstract: CONCLUSIONS
  We conclude that not all low-tone sudden deafness (SD) patients suffered from endolymphatic hydrops even if they had vertigo attack at the onset and that electrocochleography (ECochG) was a useful prognostic tool.
  
  
  OBJECTIVE
  To investigate whether low-tone SD was a precursor of Meniere's disease and whether patients with low-tone SD suffered from endolymphatic hydrops.
  
  
  METHODS
  This was a retrospective case review in the university hospital. A total of 184 patients with low-tone SD were divided into two groups with single and recurrent episodes. The progress, follow-up audiograms, and ECochG results of the patients were reviewed and compared with those of patients with high-tone SD and Meniere's disease.
  
  
  RESULTS
  In all, 83 of 177 patients with low-tone SD unaccompanied by vertigo had recurrent hearing loss; 15 of the 83 developed vertiginous attacks. The remaining 94 patients had a single episode. Three of the seven patients with low-tone SD accompanied by vertigo had recurrent hearing loss; two of the three were subsequently confirmed to have Meniere's disease. The other four had a single episode. No difference in rate of progress from SD to Meniere's disease was observed among the low-tone and the high-tone SD groups. The average -SP/AP of each group with a single episode is smaller than that of other groups with recurrent episodes and Meniere's disease.
authors.affiliation: Department of Otolaryngology, University of Toyama, Toyama, Japan.
authors.forename: Makiko
authors.initials: M
authors.lastname: Junicho
authors.forename: Shin
authors.initials: S
authors.lastname: Aso
authors.forename: Michiro
authors.initials: M
authors.lastname: Fujisaka
authors.forename: Yukio
authors.initials: Y
authors.lastname: Watanabe
mesh_terms: D001300:Audiometry, Evoked Response; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D018450:Disease Progression; D018159:Endolymphatic Hydrops / Q000175:diagnosis*; D005260:Female; D005500:Follow-Up Studies; D003639:Hearing Loss, Sudden / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000175:diagnosis*; D010897:Pitch Discrimination; D012008:Recurrence; D012189:Retrospective Studies