Non-convulsive status epilepticus in adults – an overview

Status epilepticus (SE) is the most frequent neurological emergency requiring admission on the intensive care unit (ICU). The classification of status epilepticus may be dichotomised into the “convulsive” and the “non-convulsive” form. Whereas the diagnosis of generalised convulsive status epilepticus (GCSE) is easily made in view of the evident manifestation, the diagnosis of nonconvulsive status epilepticus (NCSE) may become very difficult according to its non-spectacular and protean presentation. Non-convulsive status epilepticus is a common cause of altered mental status and delirium; and a substantial number of comatose patients in the intensive care unit may suffer from NCSE. The most important part of making a diagnosis of NCSE is to think of it at all.The definite diagnosis of NCSE is dependent on electroencephalographic (EEG) confirmation. Repetitive or, optimally, continuous EEG recording may help to closely monitor seizure activity and to guide the therapy in order to protect the patient from underand/or over-treatment. The interpretation of EEG recordings of NCSE may become challenging because of numerous artifacts caused by the patient, caregivers and devices, and because of trace elements of ambiguous significance and of waveforms mimicking epileptic activity. Non-convulsive status epilepticus was historically subdivided into the groups of complex-partial status epilepticus (focal; CPSE) and absence status (generalised; AS). Most recently, a classification proposed by the International League Against Epilepsy (ILAE) has subdivided focal NCSE into aura continua (non-convulsive simple partial SE with maintained consciousness) and into dyscognitive SE (with impaired consciousness) of