title: Prognostic significance of electrophysiological tests for facial nerve outcome in vestibular schwannoma surgery.
abstract: OBJECTIVE
  To assess the prognostic significance of pre-operative electrophysiological tests for facial nerve outcome in vestibular schwannoma surgery.
  
  
  METHODS
  Retrospective study design in a tertiary referral neurology unit. We studied a total of 123 patients with unilateral vestibular schwannoma who underwent microsurgical removal of the lesion. Nine patients were excluded because they had clinically abnormal pre-operative facial function. Pre-operative electrophysiological facial nerve function testing (EPhT) was performed. Short-term (1 month) and long-term (1 year) post-operative clinical facial nerve function were assessed.
  
  
  RESULTS
  When pre-operative facial nerve function, evaluated by EPhT, was normal, the outcome from clinical follow-up at 1-month post-operatively was excellent in 78% (i.e. HB I-II) of patients, moderate in 11% (i.e. HB III-IV), and bad in 11% (i.e. HB V-VI). After 1 year, 86% had excellent outcomes, 13% had moderate outcomes, and 1% had bad outcomes. Of all patients with normal clinical facial nerve function, 22% had an abnormal EPhT result and 78% had a normal result. No statistically significant differences could be observed in short-term and long-term post-operative facial function between the groups.
  
  
  CONCLUSIONS
  In this study, electrophysiological tests were not able to predict facial nerve outcome after vestibular schwannoma surgery. Tumour size remains the best pre-operative prognostic indicator of facial nerve function outcome, i.e. a better outcome in smaller lesions.
authors.affiliation: University Department of Otorhinolaryngology and Head & Neck Surgery, Antwerp Skull Base Centre, Sint Augustinus Hospital, Wilrijk, Antwerp.
authors.forename: J J S
authors.initials: JJ
authors.lastname: van Dinther
authors.forename: V
authors.initials: V
authors.lastname: Van Rompaey
authors.forename: T
authors.initials: T
authors.lastname: Somers
authors.forename: A
authors.initials: A
authors.lastname: Zarowski
authors.forename: F E
authors.initials: FE
authors.lastname: Offeciers
mesh_terms: D000200:Action Potentials; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004576:Electromyography / Q000379:methods*; D005154:Facial Nerve / Q000503:physiopathology*; D005158:Facial Paralysis / Q000175:diagnosis* / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000503:physiopathology / Q000601:surgery*; D013506:Otologic Surgical Procedures; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods*; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult