Treatment of status epilepticus.

OVER the past 250 years, many accounts of status epilepticus have been published, but its true frequency is difficult to judge. Status epilepticus has been recognized as a clinical entity since 1824 when Calmeil first described patients who had repeated or prolonged uninterrupted epileptic seizures. It has been estimated that about 5% of all epileptic patients at some time in their lives experience an episode of status. Each year about 8,000 persons in the United States are hospitalized because of convulsive status epilepticus. Reports of epilepsy presenting as status epilepticus vary from 12% to 77% of the published reports. Status epilepticus is defined as "a condition characterized by an epileptic seizure which is so frequently repeated or so prolonged as to create a fixed and lasting condition." For practical purposes, duration of the seizure has been defined as 30 minutes. There are essentially as many types of status epilepticus as there are types of epileptic seizures. Status may be classified by etiology—symptomatic v idiopathic—and by seizure type—generalized v focal. Generalized seizures have been further classified as convulsive or nonconvulsive. In considering the pathogenesis of status epilepticus, it is important to distinguish between underlying cause and precipitating factors. In nearly all reported series, the majority of cases have an underlying demonstrable cause of their epilepsy and have symptomatic rather than idiopathic epilepsy. Underlying factors vary with the patient's age. The precipitating factor in many cases is also the underlying cause. A change or withdrawal of anticonvulsants is a common precipitating cause of status. An association between withdrawal of anticonvulsants and status epilepticus was first sug-