Does improvement in AIS grade correlate with functional recovery in all patients with a traumatic Spinal Cord Injury?

Abstract Objective To determine what improvement on the American Spinal Injury Impairment Scale (AIS) correlates with functional status after a traumatic Spinal Cord Injury (tSCI). Design We performed an observational cohort study, analyzing prospective data from 168 tSCI patients admitted to a single Level 1 trauma Center. A multivariable analysis was performed to assess the relationship between functional status (from the SCIM: Spinal Cord Independence Measure) at 1-year follow-up and AIS grade (baseline and 1-year follow-up), while taking into account covariables describing the socio-demographic status, trauma severity and level of neurological injury. Results Individuals improving to at least AIS grade D had significantly higher SCIM score compared to those not reaching AIS 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 AIS grade. Higher final SCIM was more likely with an initial AIS grade D (β = 1.504; 95%CI: [0.46, 2.55]), and a final AIS grade D (β = 3.716; 95%CI: [2.77, 4.66]) or E (β = 4.422, 95%CI: [2.91,5.93]). Conclusion Our results suggest that reaching AIS grade D or better one year after tSCI is highly predictive of significant functional recovery, more so than the actual improvement in AIS grade from the injury to the 1-year follow-up.