The document discusses quantifying the 4 week incidence, timing, and predictors of ischemic stroke after trauma in a young cohort by electronically identifying trauma patients aged 16-50 from statewide trauma registries and hospital discharge databases and following them for ischemic stroke using state stroke registries and readmission data. Researchers found that the 4 week incidence of ischemic stroke after trauma was 0.11%, with the highest risk during the first week, and that predictors included increasing age, male sex, intracranial injury, and substance abuse.