TBI patients 30% more likely to suffer ischemic stroke

Traumatic brain injury (TBI) has been associated with subsequent ischemic stroke, a finding that could spur stroke prevention efforts in young trauma patients, according to a study published online June 26 in Neurology.

“The magnitude of this association was substantial (HR [hazard ratio] 1.31) and was similar to the association between the leading stroke risk factor, hypertension (HR 1.34), and ischemic stroke,” wrote James F. Burke, MD, MS, of the University of Michigan, Ann Arbor, and colleagues.

Ischemic stroke is the leading cause of severe disability in adults, and about 20 percent of strokes occur in those younger than 65 years, explained the authors. No specific stroke mechanisms have been identified in the young and working age populations, though, and the researchers wanted to evaluate the connection between TBI and stroke.

Using data from the state of California for 2005 to 2009, the authors evaluated a retrospective cohort of more than 1.1 million trauma patients, 37 percent of whom had TBI. The remaining patients had trauma, but not brain injury.

Over an average 28 months of follow-up after the injury, 1.1 percent of those with TBI suffered a stroke, compared with 0.9 percent of nonstroke patients, according to Burke and colleagues.

After adjusting for a number of potential confounding variables, patients with TBI visits were 30 percent more likely than non-TBI patients to experience subsequent hospitalization due to stroke. This was comparable to other vascular risk factors; the authors reported that given the high prevalence of TBI in the trauma population included in the study, TBI was responsible for more ischemic stroke than hypertension in that population.

Despite what the authors called a “robust” association, the absolute ischemic stroke risk difference between the TBI and non-TBI group remained small.

“Nonetheless, if further research definitively established TBI as a novel stroke risk factor, this would stimulate research to understand stroke pathophysiology after TBI and inform stroke prevention efforts in this young population with few vascular risk factors,” wrote Burke and colleagues.