Sometimes during embryonic development, a rare condition can form due to the absence of capillaries in the brain. The capillaries are tiny vessels in which blood flows from the arteries to the veins. In addition to transferring blood from the arteries to the veins, capillaries also help lower blood pressure due to a decrease in blood flow. Without the capillaries, blood flow increases causing the heart to work harder and resulting in congestive heart failure (CHF). Hydrocephalus, commonly referred to 'water on the brain', can also occur due to the increase in blood flow.
Nonetheless, the vein of Galen appears enlarged due to being a single vein collecting blood drainage from the arteries with the absence of the capillaries. There are commonly three categories to describe the vein of Galen malformation. The categories are divided according to age of the patient. A patient could be a baby with CHF and a loud intracranial bruit (category 1), an infant with an abnormally enlarged head along with developmental delays (category 2) or an older child with seizure, even strokes, along with learning disabilities (category 3). Malformations of the vein of Galen can be deadly particularly in category 1.
Treatments for this malformation would be to concerning the CHF or hydrocephalus medically or surgically to releive the stress on the heart and pressure on the brain due to the increased blood flow.
