Confusional status epilepticus.

Non-convulsive confusional status epilepticus (NCSE) is classically separat ed into two forms on the basis of the ictal EEG, i.e., absence status (AS) and complex partial status epilepticus (CPSE), The diagnosis is difficult o n the basis of clinical semiology alone, and requires emergency EEG investi gation. Absence status, or 'petit mal' status, is a polymorphic condition t hat can complicate many epileptic syndromes, and is the most frequently enc ountered form of NCSE. It is characterized by confusion of varying intensit y, associated in 50% of cases with bilateral periocular myoclonias. The EEG shows ictal generalized paroximal activity, normalization is obtained afte r benzodiazepine injection. In AS, there is a significant nosographic heter ogeneity. Four groups can be distinguished: i) typical AS occurs in the con text of a generalized idiopathic epilepsy; ii) atypical AS occurs in patien ts with symptomatic or cryptogenic generalized epilepsies; iii) 'de novo' A S (of late onset) is characterized by toxic or metabolic precipitating fact ors in middle-aged subjects with no previous history of epilepsy; iv) AS wi th focal characteristics occurs in subjects with a pre-existing or newly di agnosed partial epilepsy, mostly of extra-temporal origin. The majority of cases are in fact transitional forms between these four groups. CPSE is cha racterized by continuous or rapidly recurring complex partial seizures whic h may involve temporal and/or extratemporal regions. Cyclic disturbance of consciousness is characteristic of CPSE of temporal lobe origin, which requ ires vigorous treatment to prevent recurrence or cognitive sequelae. CPSE o f frontal lobe origin is a diagnostic challenge: it is rare, the symptoms a re unusual, and the patients should be documented extensively. A focal fron tal lesion is revealed in one-third of cases. (C) 2000 Editions scientifiqu es et medicales Elsevier SAS.