Epilepsy-associated death in the Southwestern Ontario: A clinicopathological correlation study

Patients with epilepsy are at elevated risk for premature mortality, of which sudden unexpected death in epilepsy (SUDEP) is one of the leading causes. SUDEP incidence varies significantly depending on the population and the methods used to document the cause of death. We performed retrospective case review at the London Health Sciences Centre for the period of 2000 to 2018. Clinical information, scene investigations, general pathology findings, toxicology, and neuropathology findings were obtained, examined, and confirmed by two neuropathologists and one epileptologist. The characteristics were compared and summarized. We also evaluated the impact of 2010 revision of Ontario Coroner Act Regulation, which significantly limited whole brain examination. Among the 12,206 cases reviewed, we identified 152 cases with a known history of epilepsy. Ninety-seven cases (64%) were classified as SUDEP. There were significantly more SUDEP decedents found dead unwitnessed at night in prone position, than non-SUDEP. Generalized seizures were strongly associated with SUDEP. A male predominance was observed in SUDEP group between 15 and 35 years old. Near half of the brains examined were "unremarkable." There was no difference in neuropathology findings between SUDEP and non-SUDEP groups. After implementation of the 2010 revision of Ontario Coroner Act Regulation, fixed whole brain examination was reduced from 88% to 7% of the epilepsy-related death investigation. Except a lower diagnosis rate of "inflammatory/infectious changes," there were no significant differences in neuropathology findings. This is the first detailed clinical-pathological study on epilepsy-related death based on a Canadian cohort. This study reinforces the previously reported findings in SUDEP and highlights the importance of clinicopathological correlation for accurate classification of epilepsy-related death.