[Hyperammoniemic encephalopathy: beyond the hepatic cause].

Hyperammoniemic encephalopathy is part of the differential -diagnosis in the presence of an acute confusional state. Although associated with liver dysfunction in the majority of cases, it can be observed in many other clinical situations. Often not investigated, the dosage of ammonium in the blood should be integrated in the biological work-up of encephalopathy of unknown origin. Mana-gement focused on etiology is paramount and usually allows for the rapid normalization of ammonium levels and resolution of the clinical syndrome.