78. Predictive value of facial nerve neurophysiological evaluation in acoustic neuroma surgery

Facial nerve palsy is probably the most frequent and less tolerated adverse event in acoustic neuroma surgery. Our goal was to identify preoperatory neurophysiological indicators of a sub-clinical facial deficit and to set up a relationship with the outcome. Since January 2014 to December 2016, 193 patients (of 214) with acoustic neuroma (size 5–45 mm) have been examinated, few days before the surgery. Standard investigation included: Blink Reflex, Electroneurography, Facial Muscles EMG. Every investigation has been made in the same laboratory, using standard EMG instruments. We classified our pathological data in minor (Mean + 1 SD) and major (M + 2 SD) anomalies. At the preoperative evaluation, just 22 of 193 (11.39%) patients had a normal electrophysiological study. In our series, 127 (65%) patients had at least a minor anomaly, and 118 (61%) had at least a major one; otherwise multiple anomalies have been frequently experienced. The neurophysiological anomalies in preoperative evaluation are much more frequent than we expected and their relationships with the tumor size are inconstant. There is a direct correlation between preoperatory findings and facial nerve outcome.