Neurophysiologic intraoperative monitoring of olfactory and optic nerves

Olfaction and vision are two sensory functions that can be lost during surgery. Intraoperative neurophysiologic monitoring can be used to monitor the integrity of the olfactory and the visual pathways during surgery. No objective methods have been established to test olfactory evoked potentials (OEPs) in the operating room. It is a challenge to obtain reliable visual-evoked potentials (VEPs) in the operating room. However, it would be very valuable to reliably monitor these pathways during surgery to predict and prevent iatrogenic neurologic injury. The aim of the review is to describe the techniques used to obtain OEPs and VEPs, the surgical procedures in which they can be used to prevent deficits, and the limitations of the current techniques and future directions for research.