Predictive value of postoperative electrophysiologic testing of the facialnerve after cerebellopontine angle surgery

Our objective was to assess the ability of postoperative electroneurography (ENoG) and electromyography (EMG) to predict clinical facial function 1 ye ar postoperatively in patients with facial paralysis and an intact facial n erve after cerebellopontine angle surgery. The study was a prospective, non randomized, uncontrolled clinical trial on an outpatient basis, at a tertia ry care hospital. Primary eligibility criteria include: (1) cerebellopontin e angle (CPA) surgery with anatomical preservation of facial nerve, (2) com plete facial nerve paralysis; and (3) 1 year follow-up. EnoG and EMG were m easured at 1 and 3 months postoperatively, House-Brackmann facial nerve gra de at 1 year postoperatively. the Kendall coefficient at rank correlation d emonstrated that the 1 and 3 month postoperative ENoG data were significant predictors of ultimate facial nerve outcome. Tracking multiple ENoG examin ations in a single patient, over time was of little predictive value. EMG w as a poor predictor of facial nerve outcome. In general, patients with dela yed facial nerve paralysis had a better ultimate facial function than patie nts with immediate paralysis. Postoperative ENoG, but not EMG wa a statisti cally significant predictor of ultimate facial nerve outcome after CPA surg ery. Patients with delayed facial paralysis had better outcomes than those with immediate facial paralysis.