The Utility of Multimodal Intraoperative Neuromonitoring in Spine Surgery: Case Series from a Lower-Middle-Income Country Perspective

Abstract

Multimodal intraoperative neuromonitoring (IOM) using somatosensory-evoked potentials and motor-evoked potentials is a sensitive and specific tool for detecting intraoperative neurologic injury during spine surgery. This study aimed to evaluate the use of multimodal IOM in a lower-middle-income country (LMIC) during cervical and thoracic spine surgery in order to prevent and predict new postoperative neurologic deficits early on. This is the first report of multimodal IOM application in LMICs. The neurophysiologist raised the cutoff warning criteria of 50 patients who underwent surgery for different cervical and thoracic pathologies to decrease postoperative neurologic deficits. We retrospectively reviewed the medical charts and neuromonitoring traces of these patients followed by calculating the sensitivity, specificity, positive predictive value, and negative predictive value of combined IOM for postoperative neurologic deficit occurrence. A significant relationship was found between the reversibility of alerts and the development of new postoperative deficits (P < 0.001). There was no relationship between the cause of alerts and the reversibility of those alerts after corrective measures were carried out (P= 0.455), or the frequency of alerts and the development of new deficits postoperatively (P= 0.578). Sensitivity, specificity, positive predictive value, and negative predictive value of combined somatosensory-evoked potential and motor-evoked potential monitoring were 100%, 80%, 62.5%, and 100%, respectively. Because of the limited experience and the many technical difficulties faced in LMICs, we found that this cutoff limit resulted in more false-positive warnings but helped to avoid any false-negative results, thus enhancing the safety of surgery.