title: The role of cervical and ocular vestibular evoked myogenic potentials in the assessment of patients with vestibular schwannomas.
abstract: OBJECTIVE
  To investigate the clinical utility of VEMPs in patients suffering from unilateral vestibular schwannoma (VS) and to determine the optimal stimulation parameter (air conducted sound, bone conducted vibration) for evaluating the function of the vestibular nerve.
  
  
  METHODS
  Data were obtained in 63 patients with non-operated VS, and 20 patients operated on VS. Vestibular function was assessed by caloric, cervical and ocular VEMP testing. 37/63 patients with conclusive ACS ocular VEMPs responses were studied separately.
  
  
  RESULTS
  In the 63 non-operated VS patients, cVEMPs were abnormal in 65.1% of patients in response to AC STB and in 49.2% of patients to AC clicks. In the 37/63 patients with positive responses from the unaffected side, oVEMPs were abnormal in 75.7% of patients with ACS, in 67.6% with AFz and in 56.8% with mastoid BCV stimulation. In 16% of the patients, VEMPs were the only abnormal test (normal caloric and normal hearing). Among the 26 patients who did not show oVEMP responses on either side with ACS, oVEMPs responses could be obtained with AFz (50%) and with mastoid stimulation (89%).
  
  
  CONCLUSIONS
  The VEMP test demonstrated significant clinical value as it yielded the only abnormal test results in some patients suffering from a unilateral vestibular schwannoma. For oVEMPs, we suggest that ACS stimulation should be the initial test. In patients who responded to ACS and who had normal responses, BCV was not required. In patients with abnormal responses on the affected side using ACS, BCV at AFz should be used to confirm abnormal function of the superior vestibular nerve. In patients who exhibited no responses on either side to ACS, BCV was the only approach allowing assessment of the function of the superior vestibular nerve. We favor using AFz stimulation first because it is easier to perform in clinical practice than mastoid stimulation.
authors.affiliation: CESEM - CNRS UMR 8194 - Université Paris Descartes, Centre Universitaire des Saints-Pères, Paris, France.
authors.forename: Elodie
authors.initials: E
authors.lastname: Chiarovano
authors.affiliation: Department of Pharmacology and Toxicology, University of Otago Medical School, Dunedin, New Zealand.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Darlington
authors.affiliation: CESEM - CNRS UMR 8194 - Université Paris Descartes, Centre Universitaire des Saints-Pères, Paris, France.
authors.forename: Pierre-Paul
authors.initials: PP
authors.lastname: Vidal
authors.affiliation: ENT Department - Salpêtrière Hospital, Paris, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Lamas
authors.affiliation: CESEM - CNRS UMR 8194 - Université Paris Descartes, Centre Universitaire des Saints-Pères, Paris, France; ENT Department - Salpêtrière Hospital, Paris, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: de Waele
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000368:Aged; D001307:Auditory Perception; D001844:Bone Conduction; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000175:diagnosis / Q000503:physiopathology*; D012027:Reflex, Vestibulo-Ocular; D012189:Retrospective Studies; D058585:Vestibular Evoked Myogenic Potentials; D014725:Vestibular Nerve / Q000503:physiopathology; D055815:Young Adult