Neurophysiological intraoperative monitoring of the glossopharyngeal nerve: technical case report.
OBJECTIVE
Neurophysiological intraoperative monitoring of the glossopharyngeal nerve has been performed only with needle electrodes inserted into the pharyngeal muscles or soft palate. We describe a noninvasive method of monitoring this cranial nerve.


METHODS
A 30-year-old man who presented with headache, as well as speech and swallowing difficulty, underwent surgical resection of a right vagus nerve schwannoma. Neurophysiological intraoperative monitoring of multiple lower cranial nerves, including the glossopharyngeal and vagus nerves, was performed.


RESULTS
The glossopharyngeal nerve was monitored with an adhesive surface electrode mounted on the cuff of a laryngeal mask airway, and the vagus nerve was monitored with a similar electrode mounted on the endotracheal tube. Successful monitoring allowed separation of the glossopharyngeal nerve from the tumor, and there was no postoperative swallowing deficit.


CONCLUSIONS
Monitoring of the glossopharyngeal nerve with surface electrodes is possible and reliable, but it must be combined with vagus nerve monitoring.
Husain
Aatif M
AM
Department of Medicine, Division of Neurology, Duke University Medical Center, and Neurodiagnostic Center, Veterans Affairs Medical Center, Durham, North Carolina 27710, USA. Aatif.husain@duke.edu
Wright
David R
DR
Stolp
Bret W
BW
Friedman
Allan H
AH
Keifer
John C
JC
D000200:Action Potentials; D000269:Adhesives; D000328:Adult; D002530:Cerebellopontine Angle / Q000473:pathology* / Q000601:surgery; D003680:Deglutition Disorders / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D004566:Electrodes; D005071:Evoked Potentials; D005930:Glossopharyngeal Nerve / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D007442:Intubation, Intratracheal / Q000295:instrumentation; D017214:Laryngeal Masks; D008297:Male; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods*; D009442:Neurilemmoma / Q000150:complications / Q000503:physiopathology / Q000601:surgery*; D010160:Palate, Soft / Q000294:innervation / Q000503:physiopathology; D010609:Pharyngeal Muscles / Q000294:innervation / Q000503:physiopathology; D016896:Treatment Outcome; D014630:Vagus Nerve / Q000473:pathology / Q000503:physiopathology*
D000269:Adhesives