Sudden unexpected death in epilepsy. Risk factors, possible mechanisms and prevention: a reappraisal.

People with epilepsy are more likely to die prematurely than those without epilepsy. The most common epilepsy-related category of death is sudden unexpected death in epilepsy (SUDEP), accounting for up to one fifth of epilepsy deaths in some series. SUDEP is more common in populations of people with intractable epilepsy, the annual incidence being as high as one in 200 patient years in these settings. The majority of people dying with SUDEP have a history of generalised tonic clonic seizures, and high seizure frequency and polytherapy also seem to be risk factors. The goal of treatment should therefore be seizure freedom, using the lowest effective number and dosage of AEDs. Evidence for many other risk factors is conflicting. The most commonly suggested mechanisms for SUDEP are cardiac abnormalities and apnoea, but the cause of SUDEP is still unknown. Clarification of risk factors and establishment of the mechanisms of SUDEP are important so that as many people as possible can be saved from SUDEP.