Posttraumatic epilepsy: long-term follow-up of children with mild traumatic brain injury

OBJECTIVE Posttraumatic epilepsy (PTE) is a known complication of traumatic brain injury (TBI). The true incidence of PTE in children is still uncertain, because most research has been based primarily on adults. This study aimed to determine the true incidence of PTE in a pediatric population with mild TBI (MTBI) and to identify risk factors for the development of epileptic events. METHODS Data were collected from electronic medical records of children 0-17 years of age, who were admitted to a single medical center between 2007 and 2009 with a diagnosis of MTBI. This prospective research consisted of a telephone survey between 2015 and 2016 of children or their caregivers, querying for information about epileptic episodes and current seizure and neurological status. The primary outcome measure was the incidence of epilepsy following TBI, which was defined as 2 unprovoked seizure episodes. Posttraumatic seizure (PTS) was defined as a single, nonrecurrent convulsive episode that occurred > 24 hours following injury. Seizures within 24 hours of the injury were defined as immediate PTS. RESULTS Of 290 children eligible for this study, 191 of them or their caregivers were reached by telephone survey and were included in the analysis. Most injuries (80.6%) were due to falls. Six children had immediate PTS. All children underwent CT imaging; of them, 72.8% demonstrated fractures and 10.5% did not demonstrate acute findings. The mean follow-up was 7.4 years. Seven children (3.7%) experienced PTS; of them, 6 (85.7%) developed epilepsy and 3 (42.9%) developed intractable epilepsy. The overall incidence of epilepsy and intractable epilepsy in this cohort was 3.1% and 1.6%, respectively. None of the children who had immediate PTS developed epilepsy. Children who developed epilepsy spent an average of 2 extra days in the hospital at the time of the injury. The mean time between trauma and onset of seizures was 3.1 years. Immediate PTS was not correlated with PTE. CONCLUSIONS In this analysis of data from medical records and long-term follow-up, MTBI was found to confer increased risk for the development of PTE and intractable PTE, of 4.5 and 8 times higher, respectively. As has been established in adults, these findings confirm that MTBI increases the risk for PTE in the pediatric population.