Cause-specific mortality in epilepsy.

Epilepsy is associated with a two- to three-fold increase in mortality. Studies of cause-specific mortality show that deaths may be classified into those that are directly or indirectly related to epilepsy, those that are related to the underlying pathology giving rise to epilepsy, and those that are unrelated to both epilepsy and its causes. Overall, direct epilepsy related deaths are infrequent. Pneumonia, especially in the elderly, central nervous system (CNS) and non-CNS neoplasias, and cerebrovascular disease are frequent causes of death. Suicides, accidental deaths, and ischemic heart disease do not appear to be significant contributors to mortality in community-based studies. In hospital/institution-based analyses, epilepsy-related deaths are common and sudden unexpected death in epilepsy (SUDEP) may account for up to 17% of all deaths in epilepsy. A small proportion of these deaths may be witnessed and most such witnessed deaths occur in relation to convulsive seizures. The exact pathogenetic mechanisms are unknown although it is very probable that lack of seizure control is an important risk factor. Patients who continue to suffer seizures appear to have an almost 40 times higher risk of mortality than those in remission.