Facial nerve outcome with a peroperative stimulation threshold under 0.05 mA.
OBJECTIVE
To evaluate the facial nerve outcome postoperatively of schwannoma vestibular surgery with a stimulation threshold (ST) lower than 0.05 mA.


METHODS
Retrospective chart review.


METHODS
A total of 106 patients had undergone schwannoma vestibular surgery between 2002 and 2008 in a tertiary center. The ST near the brainstem was obtained after the tumor removal. Facial nerve function was evaluated according to the House-Brackmann (HB) scale immediately postoperatively and at 1 year. The results were compared among the different STs used: <0.05 mA, 0.05 mA, and >0.05 mA.


RESULTS
There were 50 patients who had an ST <0.05 mA, 45 patients who had an ST of 0.05 mA, and 11 patients who had a ST >0.05 mA. Immediately postoperatively, for all of these groups we had a preservation of facial nerve function (HB I-II) in 94%, 80%, and 36% of patients, respectively (P < .0001). At 1 year in the same groups the preservation of the facial nerve function was 100%, 93%, and 82% of patients, respectively (P < .01).


CONCLUSIONS
A proximal ST of <0.05 mA is a better predictor of facial nerve function immediately postoperatively.
Otolaryngology and Head and Neck Surgery department, Centre Hospitalier Affilié Universitaire de Québec, Pavillon l'Enfant-Jésus, Laval University, Quebec City, Canada. patrick.marin.1@ulaval.ca
Patrick
P
Marin
Denis
D
Pouliot
Gaétan
G
Fradet
D000328:Adult; D000368:Aged; D004558:Electric Stimulation; D004576:Electromyography; D005154:Facial Nerve / Q000503:physiopathology*; D020220:Facial Nerve Injuries / Q000503:physiopathology* / Q000517:prevention & control*; D005158:Facial Paralysis / Q000503:physiopathology* / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009464:Neuroma, Acoustic / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications / Q000503:physiopathology* / Q000517:prevention & control*; D011237:Predictive Value of Tests; D011379:Prognosis; D012684:Sensory Thresholds / Q000502:physiology; D055815:Young Adult