Prognostic Value of Intraoperative Signal Improvement in Cervical Laminectomy: A Prospective Observational Pilot Study

Abstract The incidence of neurological deficits in cervical spine surgery has been relatively low, ranging from 0.2 to 3.2%. There has been a continuous effort to improve the outcomes in spine surgery without causing postoperative new deficits. Intraoperative neuromonitoring (IONM) is one of the adjuncts that has proven useful in improving safety. Beyond injury detection, recent interest has focused on whether intraoperative signal improvement reflects functional recovery and prognostication, particularly in cervical myelopathy. To evaluate the prognostic value of intraoperative improvement in somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) during cervical laminectomy, and to assess its association with early postoperative neurological outcomes in patients with degenerative cervical myelopathy. This prospective observational pilot study included 50 adult patients with degenerative cervical myelopathy undergoing cervical laminectomy along with multimodal IONM. Intraoperative signal improvement was defined as a ≥50% increase in MEP amplitude and/or ≥30% increase in SSEP amplitude compared with baseline, sustained until the end of surgery. Postoperative neurological assessment included motor and sensory examination immediately after recovery from anesthesia, with Nurick grading assessed at postoperative day 1. Associations between intraoperative signal changes and neurological outcomes were analyzed. Fourteen patients (28%) demonstrated intraoperative signal improvement, of whom 10 (20%) showed sustained improvement. Eight of these 10 patients (80%) demonstrated improvement in Nurick grade postoperatively. No intraoperative signal loss or new postoperative neurological deficits were observed. Patients with sustained signal improvement had a significantly higher likelihood of early neurological improvement compared with those without signal change (p < 0.05). Intraoperative signal improvement was associated with early postoperative neurological improvement, suggesting a potential prognostic role of IONM in cervical decompression surgery.