PROGNOSTIC-SIGNIFICANCE OF INTRAOPERATIVE FACIAL-NERVE STIMULUS THRESHOLDS

Objective: Intraoperative facial nerve monitoring has reduced the inci dence of facial nerve paralysis associated with acoustic neuroma surge ry, but poor facial nerve outcomes continue to occur. Intraoperative p rediction of facial nerve outcome would be advantageous in patient man agement and counseling. This study seeks to evaluate intraoperative fa cial nerve stimulus thresholds as a tool for predicting postoperative facial nerve outcome. Study Design: This study is a prospective clinic al study of the prognostic value of intraoperative stimulus thresholds . Setting: The study was performed at a tertiary referral center. Pati ents: There were 109 patients undergoing excision of acoustic neuromas included in this study. Interventions: The minimum current required t o stimulate the facial nerve at the brain stem was prospectively recor ded after excision of the acoustic neuroma. Main Outcome Measures: Fac ial nerve outcome was evaluated by the House-Brackmann grade. Results: A statistically significant relationship was found between poor initi al facial nerve outcome and higher stimulus thresholds. Long-term impa ired facial function was also more common in the higher stimulus group compared to that of the lower stimulus groups. Conclusions: Although these findings suggest that intraoperative stimulus thresholds have pr ognostic potential, other prognostic factors should also be considered and additional research is needed.