Magnetic Resonance Imaging Evidence of Therapeutic Efficacy of Timing of Decompression in American Spinal Injury Association Impairment Scale Grades A to C Cervical Spinal Cord Injury Patients

Abstract

Abstract INTRODUCTION In traumatic cervical spinal cord injury (SCI), the therapeutic effect of surgery and its timing as neuroprotective measures remain uncertain. Additionally, the relationship between timing of decompression, extent of decompression, imaging biomarkers evidence of injury severity, and outcome are incompletely understood. METHODS We investigated the effect of timing of decompression and long-term neurological outcome in patients with postoperatively confirmed decompression using computed tomography (CT) and magnetic resonance imaging (MRI) studies. A total of 6 mo after cervical SCI, American Spinal Injury Association Impairment Scale (AIS) grade conversion was determined in 72 AIS grades A, B, and C patients whose postoperative CT and MRI confirmed spinal cord decompression. A total of 32 patients underwent decompressive surgery less than 12 hr from injury, 25 within 12 to 24 hr, and 15 more than 24 hr after trauma. RESULTS Age, gender, injury mechanism, intramedullary lesion length (IMLL) on MRI, admission American Spinal Injury Association (ASIA) motor score, and surgical technique were not statistically different in-between groups. Motor complete patients (P = .009) and those with fracture dislocations (P = .01) tended to be operated earlier. One or more grade improvement was 55.6% in AIS grade A, 60.9% in AIS grade B, and 86.4% in AIS grade C patients. Admission AIS motor score (P = .0004) and preoperative IMLL (P = 0001) were the strongest predictors of neurological outcome. AIS grade improvement was 65.6% in patients undergoing decompressive surgery within 12 hr after trauma, 60% in patients undergoing surgery within 12 to 24 hr, and 80% when decompression was performed more than 24 hr after injury (P = .424). Multiple regression analysis of all significant and marginally significant variables revealed that the only significant variable predictive of AIS grade conversion to a better grade was IMLL (odds ratio 133.51, CI 11.68-1525.71, P < .0001). CONCLUSION In patients with postoperative CT and MRI confirmation of decompression following traumatic cervical SCI, preoperative IMLL and not the timing of surgery appears to determine long-term neurological outcome.