Abstracts

Rationale: Sudden Unexpected Death in Epilepsy (SUDEP) is a devastating cause of mortality in individuals with epilepsy. In the pediatric population, approximately 1 in 4500 children living with epilepsy each year will die of SUDEP. The major risk factor for SUDEP is the presence and importantly the frequency of generalized tonic-clonic seizures. Risk factors for SUDEP have been studied in adults; however, pediatric specific factors are not as well known. We aimed to identify potential pediatric risk factors for SUDEP through the development of a national, multi-centered population based registry for SUDEP. Methods: Children with epilepsy with an unexpected death were sought for enrollment. Inclusion criteria were: age at death < 18 years, history of epilepsy (≥ 2 seizures), death that was sudden and unexpected and when available autopsy that determined no anatomical or toxicological cause of death. Deaths secondary to trauma and drowning were excluded. Cases were collected from three unique sources: Ontario Forensic Pathology Service (OFPS), Canadian Pediatric Epilepsy Network (CPEN) and Canadian Pediatric Surveillance Program (CPSP). Results: Thirty-two cases of SUDEP were identified. Fifty-nine percent were males. The median age at death and duration of epilepsy were 8.3 years (range: 6 months – 17.9 years) and 6.8 years respectively (range: 2 months – 15 years). The age of seizure onset was known in 24 children; median age of seizure onset: 8.5 months and 96% had seizure onset before 5 years. At the time of death, 26 children were on AEDs, 15 of whom were treated on ≥ 2 AEDs. Twenty-three were globally delayed. Three children had Dravet Syndrome.  The seizure types in the 6 months prior to death were known in 21 cases: 19 children had generalized seizure types (13 with GTCs), 1 had focal seizures and 1 child was seizure free. In twenty-seven, the state before death was known; 25 children (93%) were asleep and 2 (7%) were awake. Two children had a seizure observed at the time of death and 9 had evidence of a recent seizure. Death was unwitnessed in 21 (81%) and witnessed in 5 (19%). Twenty-three children had information regarding the presence of recent infection and in 13 (57%) caregivers reported a recent infection. Conclusions: We have identified 11 new cases of pediatric SUDEP, not previously reported. The majority of children in our cohort continue to be characterized by early-onset epilepsy and global delay. A slight male predominance has now been observed in the cohort. With additional case collection, we have consistently illustrated that most SUDEP deaths are unwitnessed and in sleep. Further, we have observed that generalized seizure types appear more common than other types in the 6 months prior to death (when seizure type is known). Two additional cases of Dravet Syndrome have been identified, highlighting risk of SUDEP in this group. Similar to our earlier cohort, a recent infection was documented in several children before death. Infection may lower seizure threshold and trigger a terminal seizure. This finding may potentially support increased supervision around the time of illness in children with epilepsy. Funding: Funding was received by CURE and the Ontario Brain Institute.