Does Improvement in American Spinal Injury Association Impairment Scale Grade Correlate With Functional Recovery in All Patients With a Traumatic Spinal Cord Injury?

OBJECTIVE: The aim of the study is to determine what improvement on the American Spinal Injury Impairment Scale correlates with functional status after a traumatic spinal cord injury. DESIGN: We performed an observational cohort study, analyzing prospective data from 168 patients with traumatic spinal cord injury admitted to a single level 1 trauma center. A multivariable analysis was performed to assess the relationship between functional status (from the Spinal Cord Independence Measure) at 1-year follow-up and American Spinal Injury Impairment Scale grade (baseline and 1-yr follow-up), while taking into account covariables describing the sociodemographic status, trauma severity, and level of neurological injury. RESULTS: Individuals improving to at least American Spinal Injury Impairment Scale grade D had significantly higher Spinal Cord Independence Measure score compared with those not reaching American Spinal Injury Impairment Scale D (89.3 ± 15.2 vs. 52.1 ± 20.4) and were more likely to reach functional independence (68.5% vs. 3.6%), regardless of the baseline American Spinal Injury Impairment Scale grade. Higher final Spinal Cord Independence Measure was more likely with an initial American Spinal Injury Impairment Scale grade D (ß = 1.504; 95% confidence interval = 0.46­2.55), and a final American Spinal Injury Impairment Scale grade D (ß = 3.716; 95% CI = 2.77­4.66) or E (ß = 4.422; 95% CI = 2.91­5.93). CONCLUSIONS: Our results suggest that reaching American Spinal Injury Impairment Scale grade D or better 1 yr after traumatic spinal cord injury is highly predictive of significant functional recovery, more so than the actual improvement in American Spinal Injury Impairment Scale grade from the injury to the 1-yr follow-up.