Recent advances of brainstem auditory evoked potentials during microvascular decompression surgery

Hemifacial spasm (HFS) is due to the vascular compression of the facial nerve at its root exit zone (REZ). Microvascular decompression (MVD) of the facial nerve near the REZ is an effective and curative treatment for HFS. Since the cochlear nerve lies directly adjacent to the facial nerve, postoperative hearing loss frequently occurs during MVD surgery for HFS. However, the rate of postoperative hearing loss has decreased since introducing the intraoperative neurophysiologic monitoring (IONM) of brainstem auditory evoked potentials (BAEPs). There have been many advances on this field in the recent decade. This article aimed to review and present advances in IONM of BAEPs.