SUDEP is defined as "sudden unexpected, witnessed or unwitnessed, non-traumatic and non-drowning death in an individual with epilepsy, with or without evidence of a seizure and excluding documented status epilepticus where post-mortem examination does not reveal a cause for death".

_{NASHEF, L., SO, E. L., RYVLIN, P. & TOMSON, T. 2012. Unifying the definitions of sudden unexpected death in epilepsy. Epilepsia, 53, 227-33}