Status epilepticus: the interaction of epilepsy and acute brain disease.

We identified 217 patients with status epilepticus (SE), including all seizure types from all etiologies, over a 3-year period. There was a significant interaction between organic brain disease and a history of epilepsy in the development of SE. The majority of patients (59%) had no history of epilepsy. These patients were more likely to have acute precipitants associated with SE and less likely to have had prior brain disease. They were older, were more likely to have generalized convulsive seizures, and had a high proportionate mortality. Among the 88 patients with a history of epilepsy, a higher proportion had prior brain insults, but fewer had acute precipitants. These patients were younger and their mortality was low, but they often had recurrent SE before and after the identified episode. Significant acute or prior brain disease is an important factor in the development of SE, even in patients with a history of epilepsy.