Do Patients With Chronic Diabetes Have Worse Motor Outcomes After Cervical ASIA C Traumatic Spinal Cord Injury?

STUDY DESIGN: This was a level IV retrospective prognostic study. OBJECTIVE: The objective of this study was to determine if patients with chronic diabetes have worse functional outcomes and motor recovery after cervical traumatic spinal cord injury (TSCI). SUMMARY OF BACKGROUND DATA: Diabetes mellitus has multiple deleterious neurological effects and has been shown to worsen elective cervical spine surgery outcomes. Prior literature has scarcely characterized the impact of chronic diabetes on motor and functional outcomes after TSCI. METHODS: The National Spinal Cord Injury Statistical Center (NSCISC) database was utilized to retrospectively collect data on cervical American Spinal Injury Association (ASIA) C TSCI between 2011 and 2016. Patients were divided into diabetes and nondiabetes groups. Primary outcomes included wheelchair requirement and ambulatory status 1 year after injury. Secondary outcomes were motor score collected at the time of rehab admission, rehab discharge, and 1-year follow-up. All outcome variables were analyzed using univariate and multivariate regression to assess for differences between diabetes and nondiabetes groups and possible confounders. RESULTS: A total of 219 patients met the inclusion criteria for the study: 193 without diabetes and 26 with diabetes (12.0%). After controlling for confounders, patients with diabetes had had significantly increased wheelchair requirement (83.3% vs. 51.8%, relative risk=1.63, 95% confidence interval: 1.20-1.83, P =0.009 multivariate) and decreased ambulatory rates (50% vs. 67.9%, relative risk=0.55, 95% confidence interval: 0.25-0.98, P =0.042 multivariate) at 1 year. They also had no difference in average total motor scores at rehab admission but significantly worse total motor scores at rehab discharge (50.6±23.3 vs. 60.3±21.4, P =0.033 univariate, P =0.002 multivariate). CONCLUSIONS: Patients with diabetes have increased wheelchair requirement and decreased ambulatory ability at 1 year after the injury as well as diminished recovery in motor scores after motor-incomplete cervical TSCI. These patients may be targets for aggressive diabetic screening and intervention to minimize negative outcomes.