Monitoring of Facial Nerve Motor Function during Skull Base Surgery using Transcranial Electrocortical Stimulation

Objective: Transcranial electrocortical stimulation (TES) is used routinely in neurosurgery to monitor major motor pathways intra-operatively. Monitoring of facial nerve (FN) function is usually performed either by using free running electromyography (EMG) or by direct stimulation of the FN. TES has only recently been used to also monitor FN function, however, the technique and parameters for FN MEP monitoring are so far not standardized. It was the goal of this study to develop a TES protocol for reliable monitoring of FN MEPs. Methods: FN MEPs were recorded intra-operatively from 63 patients undergoing surgeri…