Long-term Morbidity Risks by Level of Preserved Neurological Function Post-sci

Introduction: Spinal cord injury (SCI) is a debilitating condition with annual US incidence of 17,000. SCI results in several secondary health conditions and complications. Level of preserved neurological function (LPNF) may determine motor and sensory deficits, but its contribution to long-term morbidity and quality of life (QOL) metrics have not been well-elucidated.

Methods: We retrospectively analyzed the National Spinal Cord Injury Model Systems Database representing 29,310 patients with SCIs between 1973 to 2021 with at least one follow-up data point 1-50 years post-injury. We fit multilinear regression models using patient age; sex; time point; associated vertebral Fx/Dis, non-spinal injury, spine surgery, and spinal injury vertebral levels at admit and discharge as independent/control variables; and various morbidities post-injury and QOL metrics as dependent variables. LPNF was analyzed as aggregate (Cervical/Thoracic/Lumbar/Sacral) and discrete levels (e.g. T5).

Results: Lumbar and Thoracic LPNF weakly correlated with the presence, whereas Cervical level correlated with severity of bladder incontinence. Notably, L1/T7/T8/T11 showed moderate negative correlation with severity. Lumbar LPNF correlated with functional bowel independence, notably levels L1-2. Lumbar-Sacral and Thoracic-Sacral LPNF correlated with CHART survey Mobility (notably L2-5) and Social Integration (notably T4,12) scores respectively. New incidence of depression was not significantly affected, however, PHQ-9 correlated with Cervical-Thoracic LPNF. Cervical-Lumbar LPNF correlated with greater pain severity ratings, particularly levels T3,7,9,10. Lumbar LPNF correlated with number of falls (notably L1-2). Lumbar-Sacral LPNF correlated with life satisfaction score.

Conclusion : In this retrospective analysis, the LPNF in spinal cord injury (SCI) patients demonstrated limited associations with general health comorbidities but showed specific correlations with bladder and bowel independence, mobility, social integration, and pain severity. Notably, lumbar and sacral LPNF were linked to improved life satisfaction, while cervical and thoracic levels correlated with increased depression severity and pain. These findings highlight LPNF as a potential predictor for targeted quality-of-life interventions in SCI patients.