FACIAL-NERVE FUNCTION FOLLOWING CEREBELLOPONTINE ANGLE SURGERY - PROGNOSTIC VALUE OF ELECTRONEUROGRAPHY

Preoperative counseling of patients, regarding facial nerve function f ollowing cerebellopontine angle (CPA) surgery, has remained a difficul t task. Facial nerve electroneurography (ENoG) or evoked electromyogra phy can detect subclinical neural degeneration. This test was used in 44 patients undergoing CPA surgery, and facial nerve function was foll owed postoperatively. A normal preoperative ENoG study appeared to pre dict an 81 percent and 84 percent chance of good (House grade I-II) ea rly and late postoperative facial function, respectively. An abnormal test is not as reliable. The relation of preoperative ENoG results wit h tumor size and tumor adherence to the facial nerve is investigated. Electroneurography appears to be a useful preoperative test when couns eling patients regarding facial function following CPA surgery.