title: Glycerol affects vestibular evoked myogenic potentials in Meniere's disease.
abstract: OBJECTIVE
  to show that abnormal vestibular evoked myogenic potentials on the sternocleidomastoid muscle (SCM) in patients with unilateral Meniere's disease are caused by endolymphatic hydrops.
  
  
  METHODS
  six normal volunteers and 17 patients with unilateral Meniere's disease were examined.
  
  
  METHODS
  click-evoked myogenic potentials were recorded with surface electrodes over each SCM. Responses evoked by clicks recorded after oral administration of glycerol (1.3 g/kg body weight) were compared with those recorded before administration.
  
  
  RESULTS
  the change rate of the p13-n23 amplitude was calculated. The mean+standard deviation (S.D.) of the change rate was 3.52+14.6% in normal subjects. On the unaffected side of patients the change rates were within the normal range (within the mean+/-2S.D.) in 13 patients, and three ears showed significant decrease. Only one ear showed significant increase. On the affected side, five ears showed significant increase of the amplitude while two ears showed significant decrease after oral administration of glycerol. Effects on evoked myogenic potentials were independent of those on pure tone hearing.
  
  
  CONCLUSIONS
  vestibular evoked myogenic potentials in some patients with unilateral Meniere's disease were improved by oral administration of glycerol. This result suggests that abnormal vestibular evoked myogenic potentials in patients with unilateral Meniere's disease could result from endolymphatic hydrops.
authors.affiliation: Department of Otolaryngology, Faculty of Medicine, University of Tokyo, 7-3-1 Hongo, Tokyo 113-8655, Japan. toshi-tky@umin.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Murofushi
authors.forename: M
authors.initials: M
authors.lastname: Matsuzaki
authors.forename: H
authors.initials: H
authors.lastname: Takegoshi
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone / Q000379:methods; D001309:Auditory Threshold / Q000187:drug effects; D018159:Endolymphatic Hydrops / Q000503:physiopathology; D005071:Evoked Potentials / Q000187:drug effects*; D005260:Female; D005990:Glycerol / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008575:Meniere Disease / Q000378:metabolism* / Q000503:physiopathology*; D008875:Middle Aged; D009124:Muscle Proteins / Q000378:metabolism*; D012444:Saccule and Utricle / Q000187:drug effects / Q000378:metabolism; D014722:Vestibule, Labyrinth / Q000187:drug effects* / Q000378:metabolism*
chemical_list: D009124:Muscle Proteins; D005990:Glycerol