EEG in NCSE

onconvulsive status epilepticus (NCSE) is defined as prolonged or recurrent electrographic seizure activity lasting more than 30 minutes without prominent motor (i.e. convulsive) clinical symptoms. There are as many types of NCSE as there are nonconvulsive epileptic seizures (Table 1). The hallmark of NCSE is an altered level of consciousness, which may range from mild confusion, inattention, or bizarre behavior to stupor or coma. Motor movements such as automatisms, eye deviation or nystagmoid eye jerks, or limb or facial twitching may be seen. Because NCSE cannot be clinically distinguished from other conditions causing stupor or coma, the electroencephalogram (EEG) is an essential tool for the diagnosis and classification of NCSE. The EEG criteria for NCSE are subjective and somewhat arbitrary, however, and even experienced electroencephalographers often disagree on whether a particular EEG pattern represents NCSE. This article will review the EEG diagnostic criteria for NCSE and common EEG patterns that can be confused with NCSE.