Electromyographic evaluation of facial nerve damage in acoustic neuroma surgery

Citation
Y. Nakao et al., Electromyographic evaluation of facial nerve damage in acoustic neuroma surgery, OTOL NEURO, 22(4), 2001, pp. 554-557
Citations number
9
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Otolaryngology
Journal title
OTOLOGY & NEUROTOLOGY
ISSN journal
1531-7129 → ACNP
Volume
22
Issue
4
Year of publication
2001
Pages
554 - 557
Database
ISI
SICI code
1531-7129(200107)22:4<554:EEOFND>2.0.ZU;2-G
Abstract
Objective: This study aimed to determine whether postoperative facial nerve paralysis or surgical manipulation causing paralysis could be predicted on train responses during intraoperative facial nerve monitoring in acoustic neuroma surgery. Study Design and Setting: This was a prospective study performed at a terti ary referral center. Patients and Methods: Train responses were recorded on a floppy disk and co mpared with postoperative facial nerve function in 51 patients who underwen t enlarged translabyrinthine acoustic neuroma surgery. Main Outcome Measures: The number, duration, frequency, and peak-to-peak am plitude of train responses were analyzed and compared with postoperative fa cial nerve function. Results: Trains were observed in 42 of 51 patients. Six of seven patients w ith high-amplitude trains more than 250 muV, and three of five patients wit h bomber-type high-frequency trains elicited during tumor dissection from t he facial nerve or stretching the nerve, showed severe facial nerve dysfunc tion. On the other hand, seven of the nine patients with no trains also sho wed severe facial nerve dysfunction. Conclusions: The presence of high-amplitude or high-frequency trains elicit ed by surgical manipulation to the facial nerve seems to indicate a critica l situation for the facial nerve. However, certain types of mechanical trau ma resulting in severe facial nerve paralysis cannot be identified by train responses.