Brain damage in the premature infant. Early lesions and new aspects of sequelae.

In spite of a significant decrease of the mortality and morbidity of neonates, cerebral damage in the premature infant remains the major concern for the neonatologist. Intraventricular hemorrhage (IVH) and necrosis of the white matter (leukomalacia) are the two main lesions. Early morphological aspects have been known for many years, but the use of computerized tomography (CT scan) and ultrasonography (US) through the anterior fontanelle have led to renewed interest and the general recognition of IVH. Localization, extent and frequency of the lesions can readily be established. However the early diagnosis of leukomalacia is still uncertain. Long survival, with mechanical ventilation of severely ill infants, has made it possible to follow the natural history of the lesions and has modified the relative frequency of their occurrence. Posthemorrhagic hydrocephalus, sclerosis of the centrum semiovale and multicystic encephalopathy are now commonly found at autopsy of infants who have survived for several weeks.