Posttraumatic epilepsy in chronic disorders of consciousness due to severe traumatic brain injury after traffic accidents

Purpose To evaluate the clinical state of posttraumatic epilepsy (PTE) in patients with chronic disorders of consciousness (CDC) due to severe traumatic brain injury (STBI) after traffic accidents and clarify the risk factors for seizure occurrence in such patients. Methods Two hundred ninety-three patients with CDC due to STBI (mean age at admission [±standard deviation]: 36.4±17.9 years; men: 71.7%; mean duration of injury to admission: 416±732 days; mean hospitalization time: 899±319 days) were enrolled in this study. We retrospectively investigated the relationship between seizure conditions (type and frequency) and clinical data, including age, sex, pathological types of brain injury, with/without surgical intervention, degree of CDC, and administration of antiseizure medications (ASMs). Results Overall, 52.9% (n=155/293) and 64.2% of the patients (n=183/of 285 patients surviving at discharge) were administered ASMs at admission and discharge, respectively. One hundred thirty-two patients (45.1%) experienced epileptic seizures during hospitalization, and the mean seizure frequency was 4.0±0.4 times per year. In multivariate analysis, significant and independent risk factors of seizure occurrence were revealed to be male sex, high National Agency for Automotive Safety and Victims’ Aid score, hypoxic encephalopathy, and history of the neurosurgical operations. Conclusion The high prevalence of PTE in patients with CDC due to STBI, and the significant and independent risk factors for seizure occurrence in the chronic clinical phase were revealed. We expect that this study will aid toward improving clinical assessment and management of epileptic seizures in the population.