title: Prognostic factors for hearing preservation in vestibular schwannoma surgery.
abstract: OBJECTIVE
  To determine whether prognostic indicators for hearing preservation could be identified in patients with vestibular schwannoma undergoing middle fossa craniotomy resection.
  
  
  METHODS
  Prospective case review.
  
  
  METHODS
  Private practice tertiary referral center.
  
  
  METHODS
  333 patients with serviceable hearing and vestibular schwannoma resected by middle fossa craniotomy from 1992 to 1998.
  
  
  METHODS
  Potential prognostic indicators, including tumor size and nerve of origin, preoperative pure-tone average, speech discrimination, distortion product otoacoustic emission testing, age, auditory brainstem response (ABR), and electronystagmography.
  
  
  RESULTS
  Postoperative hearing near preoperative levels was attained in 167 patients (50%), with an American Academy of Otolaryngology-Head and Neck Surgery Class A hearing result in 33% and a Class B result in 26%. Comparison of potential prognostic indicators between groups with hearing preserved and the group with no measurable hearing revealed significant differences in preoperative hearing, ABR, and tumor origin data. Better preoperative hearing, shorter intraaural wave V latency, shorter absolute wave V latency, and superior vestibular nerve origin were associated with higher rates of hearing preservation.
  
  
  CONCLUSIONS
  Preoperative hearing status, ABR, and intraoperative tumor origin data were shown to be of value as prognostic indicators.
authors.affiliation: House Ear Clinic and House Ear Institute, Clinical Studies Department, Los Angeles, California 90057, USA.
authors.forename: D E
authors.initials: DE
authors.lastname: Brackmann
authors.forename: R M
authors.initials: RM
authors.lastname: Owens
authors.forename: R A
authors.initials: RA
authors.lastname: Friedman
authors.forename: W E
authors.initials: WE
authors.lastname: Hitselberger
authors.forename: A
authors.initials: A
authors.lastname: De la Cruz
authors.forename: J W
authors.initials: JW
authors.lastname: House
authors.forename: R A
authors.initials: RA
authors.lastname: Nelson
authors.forename: W M
authors.initials: WM
authors.lastname: Luxford
authors.forename: W H
authors.initials: WH
authors.lastname: Slattery
authors.forename: J N
authors.initials: JN
authors.lastname: Fayad
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone / Q000379:methods; D001309:Auditory Threshold / Q000502:physiology; D002648:Child; D004584:Electronystagmography / Q000379:methods; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D006309:Hearing / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000601:surgery*; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology; D011182:Postoperative Care; D011300:Preoperative Care; D011379:Prognosis; D011446:Prospective Studies; D014722:Vestibule, Labyrinth / Q000601:surgery*