Prediction of facial nerve outcome using electromyographic responses in acoustic neuroma surgery.
OBJECTIVE
To determine whether early and late postoperative facial nerve function can be predicted on the basis of electromyographic responses in acoustic neuroma surgery.


METHODS
Prospective blinded study.


METHODS
Tertiary referral center.


METHODS
Burst and train electromyographic responses were recorded intraoperatively during the last step of vestibular schwannoma removal. The responses were classified and compared with early and late postoperative facial function in 49 patients who underwent enlarged translabyrinthine acoustic neuroma surgery.


RESULTS
In the early postoperative period, 20 of 22 patients with an irritable pattern and 10 of 13 patients with an ordinary pattern had Grade III or better facial nerve function, whereas all 3 patients with a stray pattern and 9 of 11 patients with a silent pattern had Grade V or VI. In the late postoperative period, on the other hand, Grade III or better facial nerve function was achieved in 37 of 38 patients with an irritable, stray, or ordinary pattern, but the facial nerve function remained at Grade V or VI in 2 patients with the silent pattern.


CONCLUSIONS
Patients with mechanically evoked facial electromyographic responses to the last step of tumor dissection may not experience severe facial nerve dysfunction or show a remarkable improvement. However, patients with silent electromyographic responses during this step tend to experience severe facial nerve dysfunction early in the postoperative course, and some patients may not show any functional improvement.
Nakao
Yoshiaki
Y
Department of Otolaryngology, Nagasaki University School of Medicine, Nagasaki, Japan.
Piccirillo
Enrico
E
Falcioni
Maurizio
M
Taibah
Abdelkader
A
Russo
Alessandra
A
Kobayashi
Toshimitsu
T
Sanna
Mario
M
D000328:Adult; D000368:Aged; D004576:Electromyography / Q000379:methods; D005154:Facial Nerve / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009464:Neuroma, Acoustic / Q000503:physiopathology* / Q000601:surgery*; D013506:Otologic Surgical Procedures / Q000379:methods; D011182:Postoperative Care; D011237:Predictive Value of Tests; D011446:Prospective Studies