[Nosology and ultrasound findings in porencephaly].

Congenital cerebral defects can be classified into two groups of porencephaly. Agenetic porencephaly results from development disturbances during early neuronal migration and can often be observed in the region of the fissura Sylvii. Encephaloclastic porencephaly, which is relatively rare, is a late prenatal or perinatal vascular lesion due to arterial ischemic stroke or venous thrombosis, and is located in the supply areas of the vessels involved. Cerebral defects can always be detected by ultrasonography. High resolution ultrasonic instruments or magnetic resonance imaging are appropriate means to find out disturbed patterns of gyration pointing to early fetal developmental disturbances.