Abstract
Objective: To quantify the risk of acute ischemic stroke (AIS) following traumatic brain injury (TBI) according to severity.
Setting: Indiana Network for Patient Care, including medical records from more than 100 Indiana hospitals and affiliated practices.
Participants: Individuals 18 years and older with TBI from 2005 to 2014.
Design: Retrospective cohort.
Main Measures: AIS incidence in the first 30, 31 to 180, and 181 days after TBI. Time to AIS using a stratified Cox proportional hazards model.
Results: Among 58 294 patients with TBI, AIS risk was greatest in the first 30 days (incidence rate = 23.3 per 1000 person-months), declining to 3.1 and 1.3 per 1000 person-months after 31 to 180 and 181 days or more, respectively. Cervical artery dissection increased the risk of AIS in the first 30 days (incidence rate = 170.9 per 1000 person-months). In the first 30 days, serious TBI increased risk for all age groups, with the largest effect observed among those aged 18 to 24 years. Over time, serious TBI modified the effect of age on AIS only for those aged 18 to 24 years.
Conclusions: These findings add to a growing body of work demonstrating that the acute and postacute stages of TBI play an accelerative role in AIS risk, particularly among younger patients, cervical artery dissection, and serious TBI.