A population-based study of risk of epilepsy after hospitalization for traumatic brain injury.

PURPOSE: This study was undertaken to determine the risk of developing posttraumatic epilepsy (PTE) within 3 years after discharge among a population-based sample of older adolescents and adults hospitalized with traumatic brain injury (TBI) in South Carolina. It also identifies characteristics related to development of PTE within this population. METHODS: A stratified random sample of persons aged 15 and older with TBI was selected from the South Carolina nonfederal hospital discharge dataset for four consecutive years. Medical records of recruits were reviewed, and they participated in up to three yearly follow-up telephone interviews. RESULTS: The cumulative incidence of PTE in the first 3 years after discharge, after adjusting for loss to follow-up, was 4.4 per 100 persons over 3 years for hospitalized mild TBI, 7.6 for moderate, and 13.6 for severe. Those with severe TBI, posttraumatic seizures prior to discharge, and a history of depression were most at risk for PTE. This higher risk group also included persons with three or more chronic medical conditions at discharge. DISCUSSION: These results raise the possibility that although some of the characteristics related to development of PTE are nonmodifiable, other factors, such as depression, might be altered with intervention. Further research into factors associated with developing PTE could lead to risk-reducing treatments.