[Maturation and neurological distress in the newborn]

In the newborn, structural and functional cerebral abnormalities are described as well as clinical manifestations of neurological distress, change with gestational age, and therefore with the degree of central nervous system maturation. The different maturational stages of the cerebral structure, their vascularization and myelinization from the gestational age of 24-25 weeks to the full-term neonate are briefly reported. The cerebral lesions and mechanisms of hypoxoischemic encephalopathy in the full-term neonate are summarized; an analysis of the various clinical symptoms and additional investigations (in particular the electroencephalogram) allows a precise prognosis to be made. In the premature newborn, there are 2 types of cerebral lesions: intraventricular hemorrhage and periventricular leukomalacia. The latter is primarily responsible for neurological sequelae. Clinical manifestations are poor and atypical; data based on complementary procedures (imaging and electroencephalography) allow an accurate evaluation to be made of the damage and neurological prognosis.