Intraoperative Sensory Signals Predict Prognosis for Patients with Traumatic Cervical Spinal Cord Injury

Abstract

In patients with traumatic cervical spinal cord injury (tCSCI), the potential role of intraoperative neuromonitoring as a prognostic tool has been insufficiently studied. This study aimed to determine if detectable signals during intraoperative neuromonitoring portend a greater likelihood of recovery for patients with tCSCI. Patients who underwent decompression and surgical fixation following tCSCI were retrospectively reviewed through previously prospectively collected data from the Surgical Timing in Acute Spinal Cord Injury Study. Improvement in American Spinal Injury Association (ASIA) motor score and ASIA Impairment Scale grade conversion rates at final follow-up were compared between patients with detectable intraoperative neuromonitoring somatosensory evoked potential (SSEP) signals and those without detectable signals. Forty-nine patients had intraoperative neuromonitoring. Patients with incomplete tCSCI had detectable lower extremity SSEPs more often than patients with complete tCSCI (56.3% vs. 23.5%, P= 0.028). There was no difference in detectable upper extremity SSEPs between complete and incomplete tCSCI (65.6% vs. 58.8%, P= 0.638). Of the 17 patients with complete tCSCI, patients with detectable lower extremity SSEPs had ASIA motor scores similar to the nondetectable cohort on admission (21.5 vs. 16.2, P= 0.609) but higher ASIA motor scores at final follow-up (57.5 vs. 27.1, P= 0.041). Of the 32 patients with incomplete spinal cord injury, there was no difference in grade conversion or motor scores between detectable and nondetectable SSEP cohorts. The presence of upper extremity SSEP signals in patients who present with complete tCSCI portends greater improvement in ASIA motor scores and likelihood of American Spinal Injury Association Impairment Scale grade conversion at final follow-up.