title: Abnormal vestibular evoked myogenic potentials in the presence of normal caloric responses.
abstract: OBJECTIVE
  Combined use of vestibular evoked myogenic potential (VEMP) and caloric response testing has enabled us to examine the function of the inferior and superior vestibular nerves separately. Although results of VEMP testing and caloric response testing have been reported for many diseases, a clinical entity showing abnormal VEMP responses but normal caloric test responses has rarely been reported. The aim of the study was to investigate clinical features of diseases showing abnormal VEMP responses with normal caloric test responses.
  
  
  METHODS
  Retrospective.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Eight hundred eleven patients with balance problems who had undergone both caloric response and VEMP testing were included in the study.
  
  
  METHODS
  The amplitudes and latencies of the first positive-negative peak of the VEMP (p13-n23) were measured.
  
  
  RESULTS
  Forty of the 811 patients (5%) were found to have abnormal VEMP responses with normal caloric test responses. Clinical diagnoses of these patients were Ménière's disease (n = 12), acoustic neuroma (n = 8), sudden deafness with vertigo (n = 6), and other diseases (n = 6). Eight patients could not be diagnosed as having a disease already recognized. Clinical manifestations of these eight patients were rotatory vertigo in six patients and non-rotatory dizziness in two. None of these patients showed abnormalities other than VEMP responses on neurologic or neurotologic examinations.
  
  
  CONCLUSIONS
  Apart from Ménière's disease, acoustic neuroma, and sudden deafness with vertigo, which are already known as diseases with abnormal VEMP responses but normal caloric test responses, some patients might be diagnosed as having a disease that involves only the inferior vestibular nerve region.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, University of Tokyo, Tokyo, Japan. iwashin-tky@umin.ac.jp
authors.forename: Shinichi
authors.initials: S
authors.lastname: Iwasaki
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Takai
authors.forename: Ken
authors.initials: K
authors.lastname: Ito
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Murofushi
mesh_terms: D000328:Adult; D000368:Aged; D002150:Caloric Tests; D003937:Diagnosis, Differential; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D003639:Hearing Loss, Sudden / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000175:diagnosis* / Q000503:physiopathology; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000175:diagnosis / Q000503:physiopathology; D009464:Neuroma, Acoustic / Q000175:diagnosis* / Q000503:physiopathology; D011237:Predictive Value of Tests; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012189:Retrospective Studies; D014724:Vestibular Function Tests; D014725:Vestibular Nerve / Q000503:physiopathology*