title: Extent of lesions in idiopathic sudden hearing loss with vertigo: study using click and galvanic vestibular evoked myogenic potentials.
abstract: OBJECTIVE
  To clarify the extent of the vestibular lesions in idiopathic sudden hearing loss with vertigo using vestibular evoked myogenic potentials (VEMPs) in response to click (click-VEMP) and galvanic (galvanic-VEMP) stimulation, as well as caloric tests.
  
  
  METHODS
  Retrospective study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  We enrolled 22 patients with idiopathic sudden hearing loss with vertigo in this study. All patients underwent audiometry and click-VEMP and caloric tests. Eight patients underwent a galvanic-VEMP test.
  
  
  RESULTS
  Among the 22 patients, 17 (77%) showed an absence of click-VEMPs on the affected side. In response to caloric testing, 10 patients (45%) showed a decreased response on the affected side. All 8 patients who underwent galvanic-VEMP testing showed normal responses. Most patients with decreased caloric responses (9 [90%] of 10 patients) showed an absence of click-VEMPs, whereas 9 (53%) of the 17 patients who showed abnormal click-VEMPs showed decreased caloric responses. Initial hearing level and hearing outcome significantly correlated with abnormalities on the vestibular test results.
  
  
  CONCLUSIONS
  The lesion site of vestibular disorders in idiopathic sudden hearing loss with vertigo appeared to be within the labyrinth on the basis of galvanic-VEMP findings. Results of the click-VEMP and caloric tests suggested that the saccule could be involved more frequently than the semicircular canals. The combined use of click-VEMP and caloric tests is useful for evaluating vestibular functions in idiopathic sudden hearing loss with vertigo because the extent of vestibular abnormalities correlated well with hearing outcome.
authors.affiliation: Department of Otolaryngology, 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: Hidenori
authors.initials: H
authors.lastname: Ozeki
authors.forename: Ken
authors.initials: K
authors.lastname: Ito
authors.forename: Shotaro
authors.initials: S
authors.lastname: Karino
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Murofushi
mesh_terms: D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D002150:Caloric Tests; D005072:Evoked Potentials, Auditory; D005260:Female; D003639:Hearing Loss, Sudden / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012444:Saccule and Utricle / Q000503:physiopathology; D012665:Semicircular Canals / Q000503:physiopathology; D014722:Vestibule, Labyrinth / Q000503:physiopathology*