États de mal épileptiques non convulsifs

Non convulsive confusional status epilepticus is classically divided on the basis of the ictal EEG into absence status (AS) and complex partial status epilepticus (CPSE). The clinical presentation is often insufficient to establish diagnosis and emergency EEG is required. AS is a polymorphic condition that can complicate many epileptic syndromes. In half of cases, confusion of varying intensity is associated with bilateral periocular myoclonias. Clinical and EEG normalization is obtained after intravenous benzodiazepine injection. From a nosographic point of view, four types of AS may be recognized. Typical AS occurs as part of an idiopathic generalized epilepsy. Atypical AS occurs in patients with symptomatic or cryptogenic generalized epilepsies. “De novo” AS of late onset is characterized by toxic or metabolic precipitating factors in middle-aged subjects with no previous history of epilepsy. AS with focal characteristics occurs in subjects with a preexisting or newly developing partial epilepsy, most often of extratemporal origin. Most cases are transitional forms between these four entities. CPSE is characterized by continuous or rapidly recurring complex partial seizures which may involve temporal and/or extratemporal regions. Cyclic disturbance of consciousness is characteristic of CPSE of temporal lobe origin, which requires vigorous treatment to prevent recurrence or cognitive sequelae. CPSE of frontal lobe origin is a diagnostic challenge: it is rare, the symptoms are unusual, and extensive documentation is required. A focal, frontal lesion is discovered in one third of cases.