Intraoperative Monitoring of Sensory Evoked Potentials in Neurosurgery: A Personalized Approach

Sensory evoked potentials (EPs), namely somatosensory, visual and brainstem acoustic EPs, are used in neurosurgery to monitor the corresponding functions with the aim of preventing iatrogenic neurological complications. Functional deficiency usually precede structural defect, being initially reversible, and prompt alarm may help surgeons to achieve this aim. However, sensory EPs registration requires presenting multiple stimuli and averaging of responses, which signifi-cantly lengthen this procedure. As delays can make intraoperative neuromonitoring (IONM) in-effective, it is important to reduce EP recording time. The possibility of speeding up EP recording relies on differences between IONM and clinical neurophysiology (CN; all sensory EPs were borrowed to IONM from CN). Namely, in IONM, the patient is her/his own control and neurophysiologist is less constrained by norms and standards when in CN. Therefore, neurophysiologist can perform personalized selection of op-timal locations of recording electrodes, frequency filters passbands and stimulation rates. Vary-ing some or all of these parameters, it is often possible to significantly improve signal-to-noise ratio (SNR) for EPs, and accelerate EP recording by up to several times. The aim of this paper is to review how this personalized approach is or may be applied during IONM for recording sensory EPs of each of abovementioned modalities. Also, the problems hindering implementation and dissemination of this approach and options for overcoming them are discussed here, as well as possible future developments.