Abstract TMP51: Pre-existing Atherosclerotic Risk Factors Increase Short-Term Ischemic Stroke Risk After Traumatic Head or Neck Injury

Abstract

Introduction: Trauma is an established risk factor for ischemic stroke in the young. We speculated that atherosclerotic disease, increasingly prevalent at younger ages, could predispose to dissection or artery-to-artery embolism after trauma. In a cohort of young patients with head or neck trauma, we aimed to measure the association of atherosclerotic risk factors with short-term ischemic stroke risk. Methods: Nested case-control study of patients (birth to 50 years old) with head or neck trauma while enrolled in a population-based Northern California integrated healthcare delivery system, 1997-2011. Within the trauma cohort, we identified ischemic stroke ICD-9 codes within 4 weeks of head or neck injury. A panel of neurologists reviewed charts to confirm cases of arterial ischemic stroke and determine whether stroke was attributed to trauma. Three controls per case were randomly identified from the trauma cohort. Atherosclerotic risk factors were abstracted from charts only when documented prior to trauma. We compared cases to controls using logistic regression. Results: The trauma cohort included 120,494 emergency encounters or hospital admissions for head or neck injury over the 15-year study period. We confirmed 45 cases of arterial ischemic stroke attributed to trauma and randomly identified 135 stroke-free controls for comparison. Stroke risk was not associated with sex or race/ethnicity, but was age-related: for each decade older, stroke risk increased 70% (OR 1.7, 95% CI 1.4-2.2). Other pre-existing atherosclerotic risk factors also increased stroke risk. Cases were more likely than controls to have atherosclerotic risk factors documented in the medical record prior to trauma, including hypertension, diabetes mellitus, elevated cholesterol, and history of smoking (Table). Conclusions: Pre-existing atherosclerotic risk factors appear to increase short-term ischemic stroke risk after head or neck injury.