Elevated Risk of Stroke in Young Adults After Traumatic Brain Injury: A Nationwide Study of 1 Million Individuals

Background Although stroke is commonly perceived as occurring in older adults, traumatic brain injury, one of the risk factors for stroke, is a leading cause of death in the younger adults. This study evaluated stroke risk in young‐to‐middle‐aged adults based on traumatic brain injury severity and stroke subtypes. Methods and Results For this retrospective, population‐based, cohort study, data of adults aged 18 to 49 years who were diagnosed with traumatic brain injury were obtained from the Korean National Health Insurance Service between 2010 and 2017. Traumatic brain injury history was measured based on the International Classification of Diseases, Tenth Revision (ICD‐10), codes. Posttraumatic brain injury stroke risk was analyzed using a time‐dependent Cox regression model. At baseline, 518423 patients with traumatic brain injury and 518 423 age‐ and sex‐matched controls were included. The stroke incidence rate per 1000 person‐years was 3.82 in patients with traumatic brain injury and 1.61 in controls. Stroke risk was approximately 1.89 times as high in patients with traumatic brain injury (hazard ratio, 1.89 [95% CI, 1.84–1.95]). After excluding stroke cases that occurred within 12 months following traumatic brain injury, these significant associations remained. In the subgroup analysis, patients with brain injury other than concussion had an approximately 9.34‐fold risk of intracerebral hemorrhage than did the controls. Conclusions Stroke prevention should be a priority even in young‐to‐middle‐aged adult patients with traumatic brain injury. Managing stroke risk factors through regular health checkups and modifying health‐related behaviors is necessary to prevent stroke.