Intraoperative Neuromonitoring Alarms: Relationship of the Surgeon’s Decision to Intervene (or Not) and Clinical Outcomes in a Subset of Spinal Surgical Patients with a New Postoperative Neurological Deficit

BACKGROUND: The goal of intraoperative neurophysiologic monitoring (IONM) is to minimize neurologic injury during surgery, yet patients still emerge with postoperative deficits. Few studies focus on outcomes relative to IONM alarms and interventions in this population. The authors sought to analyze the influence of IONM alarms with and without surgical intervention on patient outcome in spinal surgical patients who suffered immediate postoperative neurologic deficits. METHODS: Of 62,038 spinal surgeries with multimodality IONM, 90 patients with new or worsened postoperative neurologic deficits and whose outcomes were reported immediate to the surgery and at discharge were analyzed. Outcomes at discharge were compared for surgeries in which an IONM alarm versus no alarm occurred. Outcomes where surgical intervention was performed versus not performed were also compared. RESULTS: By discharge, 48 (53.3%) of 90 patients had complete or partial recovery of their postoperative deficit. Patients with IONM alarms and surgical interventions had an 80% (39/49) recovery rate overall versus only 26% (7/27) recovery rate of patients with IONM alarms but no interventions, and only 14% (2/14) of patients without IONM alarms and without interventions (P < 0.001). CONCLUSIONS: These data showed significantly more patients recovered by the time of discharge when a surgical intervention was precipitated by an IONM alarm versus when it was not. The authors conclude that surgical interventions based on IONM alarms do improve patient outcomes despite immediate postoperative deficit.