Secondary cystic lesions in the cerebellum in very low birth weight infants

We studied 4 very low birth weight infants with secondary cystic lesions in the cerebellum by serial cranial ultrasound and computed tomography. These infants presented severe respiratory distress, asphyxia at birth and intraventricular hemorrhage. In the neonatal period, cranial ultrasound examination showed significant intraventricular hemorrhage and posthemorrhagic ventricular dilatation with intraparenchymal hemorrhage. However, a cerebellar cyst was not seen in any of the infants. We found evidence of cerebellar hemorrhage by ultrasound in only one patient. Follow-up ultrasound examinations and CT scans showed progressive posthemorrhagic ventriculomegaly in three of the infants and large cystic lesions in the infratentorial area from 3 to 6 months old in all 4 infants. We conclude that the cystic lesions were caused by hemorrhagic and hypoxic-ischemic insults which occurred in very low birth weight infant.