Mortality Associated with Status Epilepticus

Status epilepticus (SE) is a neurologic and medical emergency associated with a high mortality rate. This strong assertion, although widely accepted, must be defined specifically to compare epidemiologic studies. Proposed definitions of SE by episode durations of 60, 20, 10, and even 5 minutes have been advocated, with briefer episode durations operationally used to prompt early treatment (1). The majority of research studies, however, have used the guidelines agreed on by the International Classification of Epileptic Seizures and by the Epilepsy Foundation of America's Working Group on Status Epilepticus, which define SE as 30 or more minutes of continuous seizure activity or two or more sequential seizures without full recovery of consciousness between seizures (2). According to a large prospective database compiled through the Greater Richmond Metropolitan Area Status Epilepticus Project (GRMASE), by using the 30-minute definition, 30-day mortality rates for subjects with seizures lasting 10 to 29 minutes was only 2.6% compared with a 19% rate in patients diagnosed with SE but who otherwise had comparable clinical features (P < .001) (3). It would appear, then, that the traditional definition of SE is a quite defensible one, as mortality statistics support the notion that after about 30 minutes of seizures, mortality takes a robust leap. Rather than adding to confusion in the literature by modifying a widely used and certainly not inappropriate definition of SE, I have advocated using the term “impending SE” to emphasize the urgency of initiating effective treatment within 30 minutes and preventing a progression of the episode from a mortality of one in 40 to a mortality of one in five (3).