Occurrence of epilepsy during the first 10 years after traumatic brain injury acquired in childhood up to the age of 18 years in the south western Swedish population-based series.

Background: The risk of seizures is increased after a traumatic brain injury (TBI), but the impact and duration of this increased risk is not well characterized in children.

Objective: To identify post-traumatic epilepsy (PTE) and post-concussion symptoms 10 years after a TBI during childhood.

Research Design: The study is a population-based retrospective follow-up study.

Procedure: Ten years after brain injury all 165 survivors, who as children (<18 years) in 1987-1991 as residents in the south western Swedish health care region had had a TBI, were invited to participate in a follow-up. A questionnaire regarding medical conditions and medication was filled out by the patients themselves or their parents as was a 21-item questionnaire (PCSQ) regarding post-concussion symptoms. Of the surviving 165 individuals, 109 participated (67%).

Results: Eight of 109 developed immediate seizures. During the follow-up period 12/109 had developed active epilepsy. Of these 12, five had had immediate seizures. The incidence of developing PTE within 10 years after a TBI was thus in this series 11%. The relative risk to develop late onset post-traumatic epilepsy (> or =1 week after injury) for those who had had immediate seizures was 9.018 (p = 0.0003, 95% CI = 3.69-22.05).

Conclusions: TBI is a relatively rare cause of epilepsy in childhood, although immediate seizures are associated with an increased risk of developing post-traumatic epilepsy.