1. A large brain AV malformation with a sizable shunt is a
common cause of cardiomegaly and congestive heart failure on the first day
of life. The shunt operates throughout gestation and the re-routing of blood
at birth increases the strain on the heart.
2. These shunts generally occur between the vein of Galen and
the middle or posterior cerebral artery. Surgical intervention can be successful
in closing the shunt.
This lesion is encountered most often in premature infants. Subependymal
matrix hemorrhages and hemorrhagic necrosis have been attributed to cerebral
hypoxia between the 25th and 35th weeks of gestation. When extensive, they
often produce massive intraventricular hemorrhage. Smaller, less severe
hemorrhages may be resorbed, leaving subependymal matrix cysts.
This coronal section of
a premature infant brain shows a subependymal matrix hemorrhage, with blood
in the adjacent ventricle.