title: Hearing outcomes following microvascular decompression for hemifacial spasm.
abstract: OBJECTIVE
  Facial nerve microvascular decompression (MVD) for hemifacial spasm (HFS) provides relief to most patients. Due to the proximity of the cochlear and facial nerves, hearing loss is a potential MVD complication, however, there is a wide range in the reported incidence of hearing loss (HL) in the literature. In order to better understand the HL incidence in our MVD population, we utilized the combination of speech discrimination scores (SDS) and air and bone pure tone threshold averages (PTA) to identify patients with no hearing change, sensorineural hearing loss, or conductive hearing loss. We also assessed the predictive value of patient-reported hearing deficits on the ultimate audiometric diagnosis of hearing loss.
  
  
  METHODS
  One hundred and fifty one patients underwent facial nerve MVD at the University of Pittsburgh Medical Center between January 2000 and December 2007. Peri-operative audiometric data, including changes in air and bone pure tone thresholds and speech discrimination scores, were analyzed retrospectively. Criteria from the 1995 American Academy of Otolaryngology Committee on Hearing and Equilibrium consensus were used to analyze post-operative hearing loss. Patient-reported hearing disturbances obtained in the immediate post-operative period were compared to seven-day post-operative conductive and sensorineural HL status.
  
  
  RESULTS
  Non-functional, non-serviceable HL (Class D) occurred in 6.6% of patients, while 10.6% developed cumulative non-functional HL (Class C and D). Twenty-nine patients (18.7%) exhibited conductive HL. While patient-reported complaints were predictive of Class C/D HL (<0.0001) with a 56.3% sensitivity and 92.6% specificity, patient-reported complaints were not strongly associated with conductive HL status (p = 0.369) with 17.2% sensitivity and 88.5% specificity.
  
  
  CONCLUSIONS
  Perioperative hearing evaluations, in conjunction with careful scrutiny of patient complaints and air-bone pure tone testing enables the physician to more precisely quote complication rates and rapidly distinguish potentially reversible conductive hearing pathologies from permanent sensorineural disorders.
authors.affiliation: Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, PA, USA.
authors.forename: Aalap
authors.initials: A
authors.lastname: Shah
authors.forename: Tara
authors.initials: T
authors.lastname: Nikonow
authors.forename: Parthasarathy
authors.initials: P
authors.lastname: Thirumala
authors.forename: Barry
authors.initials: B
authors.lastname: Hirsch
authors.forename: Yuefang
authors.initials: Y
authors.lastname: Chang
authors.forename: Paul
authors.initials: P
authors.lastname: Gardner
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Balzer
authors.forename: Miguel
authors.initials: M
authors.lastname: Habeych
authors.forename: Donald
authors.initials: D
authors.lastname: Crammond
authors.forename: Lois
authors.initials: L
authors.lastname: Burkhart
authors.forename: Michael
authors.initials: M
authors.lastname: Horowitz
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D001844:Bone Conduction; D016057:Evoked Potentials, Auditory, Brain Stem / Q000502:physiology; D005260:Female; D034381:Hearing Loss / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D006314:Hearing Loss, Conductive / Q000453:epidemiology / Q000209:etiology; D006319:Hearing Loss, Sensorineural / Q000453:epidemiology / Q000209:etiology; D019569:Hemifacial Spasm / Q000150:complications / Q000601:surgery*; D006801:Humans; D008297:Male; D061145:Microvascular Decompression Surgery / Q000379:methods*; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011183:Postoperative Complications / Q000453:epidemiology*; D012189:Retrospective Studies; D013067:Speech Perception; D016896:Treatment Outcome; D055815:Young Adult