The clinical features, diagnosis, and prognosis of nonconvulsive status epilepticus.

Nonconvulsive status epilepticus (NCSE) is a state of ongoing seizure activity for at least 30 minutes, with cognitive or behavioral changes, but without convulsive clinical manifestations. It requires EEG for confirmation. It has been categorized into groups having focal or generalized EEG epileptic activity; and by etiology and level of consciousness (which predict outcome). Points of contention include the evolving definition of what constitutes NCSE, various reasons for a delayed, missed, or misidentified diagnosis, and the optimal management of these conditions.