title: Hyperammonaemia as a cause of psychosis in an adolescent.
abstract: Diseases that cause hyperammonaemia usually appear during the neonatal period or during the first months of life as severe neurological metabolic distress. In some cases, as the one reported here, the age of onset and initial symptoms are non-specific and the episodes of acute metabolic encephalopathy may be attributed to encephalitis, poisoning or psychiatric problems. Our patient had N-acetyl glutamate synthetase deficiency due to a lack of activation by L-arginine. Treatment with N-carbamylglutamate was successful in maintaining normal ammonia levels.
  
  
  CONCLUSIONS
  We emphasise the importance of measuring ammonia levels in patients with neurological or psychiatric symptoms as part of their diagnostic work-up.
authors.affiliation: Unidad de Enfermedades Metabólicas, Servicio de Pediatría, Hospital Ramón y Cajal, Ctra de Colmenar Km 9.1, 28034 Madrid, Spain. abelanger@eresmas.com
authors.forename: Amaya
authors.initials: A
authors.lastname: Bélanger-Quintana
authors.forename: Mercedes
authors.initials: M
authors.lastname: Martínez-Pardo
authors.forename: María José
authors.initials: MJ
authors.lastname: García
authors.forename: Bendicht
authors.initials: B
authors.lastname: Wermuth
authors.forename: Julián
authors.initials: J
authors.lastname: Torres
authors.forename: Esperanza
authors.initials: E
authors.lastname: Pallarés
authors.forename: Magdalena
authors.initials: M
authors.lastname: Ugarte
mesh_terms: D000293:Adolescent; D000641:Ammonia / Q000032:analysis / Q000378:metabolism*; D005500:Follow-Up Studies; D005971:Glutamates / Q000008:administration & dosage*; D006801:Humans; D022124:Hyperammonemia / Q000150:complications* / Q000175:diagnosis* / Q000188:drug therapy; D008297:Male; D011618:Psychotic Disorders / Q000175:diagnosis / Q000188:drug therapy / Q000209:etiology*; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D005971:Glutamates; C006895:N-carbamylglutamate; D000641:Ammonia