Concomitant traumatic brain injury as a determinant of survival, and neurological and functional outcomes after traumatic spinal cord injury: A retrospective cohort study.

Background: Although concomitant traumatic brain injury (TBI) is not infrequently associated with spinal cord injury (SCI), there is relatively scarce information about the effects of concomitant TBI on outcomes after SCI.

Objective: To assess the impact of concomitant mild-to-moderate TBI on survival, and neurological and functional outcomes within the first year after acute traumatic SCI.

Design: Retrospective cohort study.

Setting: Acute spine trauma centers in the United States.

Participants: This study includes all individuals who were enrolled into the Third National Spinal Cord Injury Study (NASCIS-3). The study population was classified into SCI + TBI group and SCI-alone group. TBI was defined as a Glasgow Coma Scale score <15 on admission.

Intervention: Not applicable.

Main outcome measures: Both groups were compared regarding their survival and neurological outcomes (ie, NASCIS motor, sensory and pain scores) and functional outcome (ie, Functional Independence Measure score) within the first year following SCI. Data analyses were adjusted for major potential confounders.

Results: There were 413 individuals in the SCI-alone group and 86 individuals in the SCI + TBI group (17.2%). Both groups were comparable regarding gender distribution (p = .621). However, the SCI + TBI group was older (p < .001), had a higher proportion of complete (p = .006) and cervical SCI (p = .003), and had a higher blood alcohol level (p < .001) than the SCI-alone group. The SCI + TBI group did not significantly differ from the SCI-alone group regarding survival within the first year after SCI (p = .768). Among the survivors, concomitant mild-to-moderate TBI did not significantly affect neurological and functional outcomes at 1 year after SCI in the multiple regression analyses after adjusting for major potential confounders.

Conclusions: The results of this study suggest that concomitant mild-to-moderate TBI did not have a significant impact on survival, neurological recovery, and functional outcomes at 1 year after SCI, even though there were some epidemiological differences between SCI-alone and SCI + TBI groups.