Spinal cord injuries & disorders as a risk factor for ischemic stroke: a five-year retrospective cohort study of US...

Spinal cord injuries and disorders (SCI/D) have been reported by some studies to correlate with increased risk of ischemic cerebral stroke. However, the reports are sparse, conflicting, generally lacked SCI/D-specific analysis, and commonly had small sample sizes.

To determine whether SCI/D are a risk factor for ischemic stroke and evaluate for underlying SCI/D-related stroke risk correlations.

Using a retrospective design aimed to capture a large sample with SCI/D, first-ever stroke incidence was estimated by Poisson regression models for US Veterans with and without SCI/D during fiscal years 2017-2021 using US Veterans Health Administration and Medicare utilization data. Models were adjusted for Veteran characteristics, common stroke risk factors, and prescriptions for stroke-prophylactic medications.

Analyses included 560,314 Veterans, including 12,450 with SCI/D. Adjusting for person-days, age, sex, smoking, diabetes, hypertension, atrial fibrillation, race, ethnicity, and stroke-prophylactic medications, Veterans with SCI/D had a 19% higher stroke incidence compared to controls [incidence rate ratio (IRR) 1.19, 95%CI: 1.11-1.28]. Compared to controls, stroke incidence was 50% and 31% higher with high and low tetraplegia, respectively [IRR 1.50, 95%CI: 1.17-1.92 and IRR 1.31, 95%CI: 1.02-1.67], and markedly higher for younger Veterans with SCI/D (ages < 40 years) [IRR 2.25, 95%CI: 1.24-4.08]. Relative to controls, stroke incidence was 36% higher with non-traumatic SCI/D [IRR 1.36, 95%CI: 1.24-1.49], but not with traumatic spinal cord injury [IRR 1.05, 95%CI: 0.95-1.17].

SCI/D are a risk factor for ischemic stroke in US Veterans, especially for Veterans with tetraplegia, non-traumatic SCI/D, and younger age.