Clinical epidemiology of posttraumatic epilepsy in a group of Chinese patients

OBJECTIVE To explore the incidence, types of onset, and risk factors of posttraumatic epilepsy (PTE). METHODS This is a retrospective follow-up study of patients discharged from the Affiliated Hospital of the Medical College of the Chinese People's Armed Police Forces between September 2004 and September 2008 with a diagnosis of traumatic brain injury (TBI). RESULTS Complete clinical information was available on 2826 patients. Of the 2826 TBI patients, 141 developed PTE, providing an incidence rate of 5.0%. Twenty-four cases (0.8%) had posttraumatic seizures (PTS), of which 16 (66.7%) continued to experience after the acute phase of their TBI, accounting for 5.0% of the total PTE cases. A total of 125 cases (88.7%) were diagnosed as presenting with late-stage seizures, occurring from 10 days to three years after TBI (93/141 (66.0%) presented within six months after the TBI, 14/141 (9.9%) between six and twelve months, 22/141 (15.7%) between one and two years and only 12/141 (8.5%) between two and three years after the TBI. The severity of PTE was rated mild, medium, and severe in 3.6%, 6.9%, and 17% of the TBI patients. Multiple regression analysis was carried out to identify factors contributing to the risk of developing PTE. Five parameters contributed to the model: Older age, greater severity of brain injury, abnormal neuroimaging, surgical treatment, and early-stage seizures. CONCLUSION Age, severity of brain injury, neuroimaging results, treatment methods, and early-stage seizures are independent risk factors of PTE.