title: [Valproate-induced hyperammonemic encephalopathy].
abstract: Valproate is a drug commonly prescribed in neurology and psychiatry. Hyperammonemic encephalopathy due to valproate is a severe complication. A 44-year-old man with a past medical history of partial symptomatic epilepsy and alcoholic cirrhosis was admitted for drowsiness. He was receiving valproate and gabapentin. A valproate-induced hyperammonemic encephalopathy was diagnosed on physical examination, generalized slow waves on electroencephalogram and hyperammonemia. Valproate withdrawal led to a progressive recovery of the consciousness, with a rapid normalisation of electroencephalogram and ammonium level. The pathogenesis of this encephalopathy is not clearly established. No correlation has been shown between the severity of encephalopathy, the plasma ammonium level, the valproate dose and its plasma concentration. Additional factors have been pointed out, such as carnitine deficiency or urea cycle enzyme defects. Furthermore, our case suggests an enhancing role of the liver disease in this encephalopathy.
authors.affiliation: Service de médecine interne, hôpital Nord, Assistance publique des Hôpitaux de Marseille (AP-HM), chemin des Bourrely, Marseille cedex 15, France. bgranel@ap-hm.fr
authors.forename: B
authors.initials: B
authors.lastname: Granel
authors.forename: M
authors.initials: M
authors.lastname: Gavaret
authors.forename: X
authors.initials: X
authors.lastname: Le Baut
authors.forename: N
authors.initials: N
authors.lastname: Sautereau
authors.forename: D
authors.initials: D
authors.lastname: Rodriguez
authors.forename: P
authors.initials: P
authors.lastname: Rossi
authors.forename: D
authors.initials: D
authors.lastname: Bagnères
authors.forename: A-L
authors.initials: AL
authors.lastname: Demoux
authors.forename: Y
authors.initials: Y
authors.lastname: Francès
mesh_terms: D000328:Adult; D000927:Anticonvulsants / Q000009:adverse effects*; D006801:Humans; D022124:Hyperammonemia / Q000139:chemically induced; D008297:Male; D020258:Neurotoxicity Syndromes / Q000209:etiology*; D014635:Valproic Acid / Q000009:adverse effects*
chemical_list: D000927:Anticonvulsants; D014635:Valproic Acid