Magalhães, TiagoCampos, TeresaRodrigues, EsmeraldaVasconcelos, CarlaFontoura, ManuelVilarinho, LauraLeão‐Teles, Elisa2023-02-282023-02-282021-07J Paediatr Child Health . 2022 Jul;58(7):1270-1271. doi: 10.1111/jpc.15824. Epub 2021 Nov 2. Case Reports1034-4810http://hdl.handle.net/10400.18/8535Case ReportsKey Points: - Blood ammonia levels should be measured in every encephalopathy of unknown origin, especially when an intoxication cause is thought; - Late-onset inherited metabolic disorders may only manifest in the presence of triggering environmental factors such as some drugs (e.g. anti-epileptics); an undiagnosed metabolic disorder should be considered in such cases.engHyperammonaemic EncephalopathyBrain DiseasesDiagnosisNeurotoxicity SyndromesAnticonvulsantsAdolescentFemaleDoenças Genéticasjournal article10.1111/jpc.15824