Cochlear Implantation and Intraoperative Neurophysiological Monitoring of the Facial Nerve

Abstract

Cochlear implants (CI) provide significant benefits to patients. Given these benefits and the increasing number of CI surgeries, great care should be taken to prevent facial nerve injury. Intraoperative neurophysiological monitoring (IONM) of the facial nerve during CI surgery can greatly benefit the surgeon when combined with a thorough history and physical and appropriate pre-operative imaging. In this case, we review the pre-operative and intraoperative considerations of CI surgery and the implications of using IONM for facial nerve monitoring.

Preoperative considerations include appropriate workup, including a thorough history and physical examination with special care for audiometric history, evaluation, and preoperative imaging. Intraoperatively, special consideration should be given to IONM of the facial nerve while drilling over the facial recess. Care should be taken about specific anatomical considerations based on preoperative imaging.

IONM of the facial nerve during CI surgery can significantly help the surgeon. While rates of facial nerve injury are low in incidence during CI surgery, IONM can be especially useful in cases of variant anatomy, younger patients, congenital malformations, or revision surgeries. It is a cheap and cost-effective way to safeguard the facial nerve and should be considered during all CI surgeries.

Cochlear implantation can have tremendous benefits for patients, but the potential risks of facial nerve injury can be devastating. IONM of the facial nerve during CI surgery can help prevent such injury and do so in a cost-effective and time-efficient manner.