Incidence of Ischemic Stroke in US Veterans Living with Spinal Cord Injury: Preliminary Data
Rafer Willenberg1, Bridget Smith2, Kevin Stroupe2, Jennifer Sippel3, Zhiping Huo2, Sunil Sabharwal1
1Harvard Medical School; VA Boston Healthcare, 2Center of Innovation for Complex Chronic Healthcare (CINCCH), Hines VA Hospital, 3Spinal Cord Injuries & Disorders National Program Office, Veterans Health Administration
Objective:

In this preliminary study, we estimate the 4-year incidence of ischemic stroke and associated risk factors in United States (US) Veterans living with spinal cord injuries and disorders (SCI/D).

Background:

People with SCI/D have been reported to have an elevated risk of ischemic stroke, based on a study in the population of Taiwan [Wu et al, Neurology. 2012;78:1051–1057]. This prior study reported a cumulative incidence rate of ischemic stroke of 1.9% over 4 years subsequent to SCI, vs 0.6% in matched non-injured controls. 

Design/Methods:

We used Department of Veterans Affairs (VA) administrative databases to examine the incidence of ischemic stroke between fiscal years 2018-2021. Veterans living with strokes were identified using ICD-9 or 10 codes for cerebral infarction or sequelae of cerebral infarction. Veterans with diagnoses of ischemic strokes or sequelae during 2013-2017 were excluded. Statistical analyses included frequencies and multiple regression models.

Results:
From FY 2018-2021, 394 of 12,547 Veterans living with SCI had a newly-recorded ischemic stroke, reflecting a 4-year incidence of 3.14%, and an average annual incidence of 0.79%. Compared to Veterans with a D injury classification by the American Spinal Injury Association (ASIA) Impairment Scale, Veterans with high tetraplegia had a higher likelihood of ischemic stroke (IRR=1.91, 95%CI: 1.37 – 2.67). Compared to Veterans with traumatic SCI, Veterans with non-traumatic SCI/D also had a higher likelihood of ischemic stroke (IRR = 1.43, 95%CI: 1.13 – 1.80).
Conclusions:

US Veterans with SCI/D have a higher incidence of ischemic stroke than that reported for the Taiwanese population with SCI. Tetraplegia and a non-traumatic injury etiology seem to be SCI-centric risk factors. Further study will include comparison of stroke incidence to that of age- and sex-matched US Veterans without SCI.

10.1212/WNL.0000000000202615