Hearing outcomes following microvascular decompression for hemifacial spasm

PurposeFacial 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.MethodsOne 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.ResultsNon-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.ConclusionsPerioperative 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.