Dandy-Walker syndrome is a congenital defect involving the area of the brain that controls movement, manifesting itself in symptoms that can be dramatic or almost unnoticeable. The fourth ventricle is a channel through which fluid flows from the brain to the spinal cord, and becomes enlarged in those afflicted. The brain disorder is also characterized by a complete or partial absence of the cerebellar vermis, or the area of the brain between its two hemispheres, as well as by the formation of a cyst at the base of the skull. The increase in fluids that flow through the brain puts added pressure on both the brain and skull.
The disorder is usually diagnosed in children. Many are born with normally formed ventricles, but develop the conditions of the disorder by around one year of age. The majority of cases diagnosed involve children between three and four years old, but it can be found in children as young as nine months and as old as 12.
When Dandy-Walker syndrome begins to develop in infants, they can show signs of slow motor development and a skull that gets progressively and noticeably larger. Children beyond infancy often demonstrate outward symptoms caused by the increased pressure inside the skull, such as vomiting, convulsions, jerky and uncontrolled movements, lack of coordination, and irritability. The condition can also affect vision, including involuntary eye movements and problems with depth perception and shape recognition. Hearing loss can be present, but is not a major symptom of the syndrome.
Many of the symptoms associated with Dandy-Walker syndrome can be treated. In some cases, a tube may be inserted into the skull in order to drain excess fluid and relieve the buildup of pressure. This in turn helps to relieve some of the other symptoms caused by the swelling and pressure.
Early diagnosis is key; when diagnosed and treated at a young age, some children may be able to function at normal levels. This is variable, though, and some children may experience long-term problems and complications from the disorder. Those with multiple defects may have a shortened life span.
Causes of Dandy-Walker syndrome are not known, but it has been shown to run in families. With the birth of one child diagnosed with Dandy-Walker syndrome, parents may want to seek genetic counseling before having other children. There are a number of organizations available for counseling and aid for parents trying to understand the difficulties faced by children diagnosed with Dandy-Walker Syndrome.