Prediction of long-term facial nerve outcomes with intraoperative nerve monitoring.
OBJECTIVE
Evaluate the utility of a statistical equation using two independent intraoperative monitoring parameters in predicting long-term facial nerve function.


METHODS
Retrospective case review.


METHODS
Tertiary care hospital.


METHODS
Sixty patients undergoing resection of vestibular schwannomas with intraoperative facial nerve monitoring at a single institution.


METHODS
All patients underwent microsurgical resection of vestibular schwannomas with the use of intraoperative cranial nerve monitoring.


METHODS
Final facial nerve outcome measured using the House-Brackmann scale at least 6 months after microsurgical resection.


RESULTS
Five out of 60 (8.3%) patients demonstrated significant long-term weakness (i.e., House-Brackmann grade III or worse). Intraoperative monitoring parameters (proximal stimulation threshold, proximal-to-distal response amplitude ratio) were accurate in predicting increased risk of long-term facial nerve dysfunction when used in a logistic regression model. A Student's t test confirmed the equation result was statistically significant in differentiating long-term facial nerve outcomes.


CONCLUSIONS
Patients with immediate weakness are at higher risk of having long-term poor facial nerve function. The use of intraoperative monitoring parameters was reliable in predicting facial nerve outcomes. Patients with permanent facial nerve dysfunction often require rehabilitative procedures. The ability to predict facial nerve outcomes with intraoperative monitoring may allow early rehabilitative procedures to improve quality of life and prevent ocular complications.
Isaacson
Brandon
B
University of Michigan Hospitals, Department of Otolaryngology-Head and Neck Surgery, Ann Arbor, Michigan, USA.
Kileny
Paul R
PR
El-Kashlan
Hussam K
HK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D004558:Electric Stimulation; D004568:Electrodiagnosis / Q000295:instrumentation*; D005154:Facial Nerve / Q000503:physiopathology*; D020220:Facial Nerve Injuries / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control; D005158:Facial Paralysis / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D016343:Monitoring, Intraoperative / Q000295:instrumentation*; D009464:Neuroma, Acoustic / Q000601:surgery*; D017063:Outcome Assessment, Health Care / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000175:diagnosis / Q000503:physiopathology / Q000517:prevention & control*; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D012189:Retrospective Studies; D012306:Risk; D012684:Sensory Thresholds / Q000502:physiology