Risk and cause of death in post-traumatic epilepsy: a register-based retrospective cohort study

Abstract

ObjectivePost-traumatic epilepsy (PTE) is common, but its impact on survival after traumatic brain injury (TBI) of different severity and in different demographic patient groups is unknown. We analyzed the risk of death associated with PTE with adjustment for TBI severity, causes of death, and the contribution of epilepsy as direct or contributing cause of death.MethodsRegister-based, retrospective cohort study. All individuals hospitalized in Sweden for a TBI between 2000 and 2010 without prior seizures were identified in the National Patient Register, with follow-up until 2017. Subsequent epilepsy was identified by ICD-10 codes. Time-dependent Cox proportional hazard ratio (HR) was used to assess hazard of death, with epilepsy as a time-updated covariate. Adjusted analyses for age, gender, injury severity and comorbidities were also performed. Causes of death were analyzed using the Cause of Death Register.ResultsAmong 111 947 individuals with TBI, subsequent epilepsy diagnosis was associated with a crude HR of 2.3 (95% CI: 2.2–2.4) for death. Stratified analyses showed a HR of 7.8 (95% CI: 6.5–9.4) for death in younger individuals. Epilepsy was a more common underlying cause of death in younger individuals.ConclusionPTE is associated with a higher risk of death and epilepsy seems to contribute to a significant proportion of deaths, especially in younger age groups. Future studies on whether improved epilepsy treatment can reduce mortality are needed.