Intraoperative electromyography has a favorable impact on facial nerve function in patients with parotid gland tumor

Abstract

The aim of the present study was to evaluate the clinical usefulness of intraoperative neuromonitoring and its influence on surgery and especially the onset of facial nerve palsy. Important aspect was neurophysiological examination before and after removal of parotid gland tumor. The type, size and localization of the tumor were also examined. We included 72 patients into our study. The group of 50 patients, after parotid gland surgery without the use of neuromonitoring (group I) and the group of 24 patients operated with neuromonitoring of the facial nerve (group II). Each patient had clinical neurological examination performed, as well as the electrophysiological examination of the facial nerve before and 1 month after the surgery. Electrophysiological examination of the facial nerve included a blink reflex test and bilateral electroneurography (ENoG). In our results, one month after the surgery, the normal function of the facial nerve (grade I in House-Brackmann scale) was found in 87.5% of patients operated with neuromonitoring, whereas in patients operated without the monitoring, normal nerve function was found in 26% of patients. Interestingly, neurophysiological examination did not reveal any statistical differences in the values of latency and amplitude in patients before and after surgery in both groups. The average duration of operations without monitoring was 100.4 minutes, and with the use of neuromonitoring 86.25 minutes. The level of statistical significance was p = 0.052, however. In conclusion, the use of intraoperative facial nerve monitoring reduces the risk of temporary facial nerve palsy and may shorten time of the surgery.