Encéphalopathie néonatale: quand évoquer une maladie métabolique héréditaire ?

Abstract

Inborn errors of metabolism (IEM) are individually rare but collectively numerous. Clinical presentations of IEM should be various, including neonatal encephalopathy mimicking a perinatal asphyxia. The diagnosis of IEM should be considered in all situations of neonatal distress that persist and remain unexplained after usual investigations and the initial treatment. It is essential to do not misdiagnose IEM because this diagnosis may modify therapeutic strategy and prognosis, allow predicting the risk of disease recurrence, and may have medico-legal implications in some cases. Metabolic investigations must be proposed when symptoms cannot easily be attributed to perinatal asphyxia or some other common cause. Diagnosis of IEM should also be considered in situations of consanguinity, or of similar symptoms in siblings. When an IEM is suspected, simple metabolic investigations are helpful to orient diagnosis and treatments. Practically, four conditions may be individualized: neurological distress with lactic acidosis or with multi-organ dysfunction, generalized seizures and neurological distress after a symptom-free period.