Q&A: What Is Dandy-Walker Malformation?

Dandy-Walker malformation or Dandy Walker syndrome (DWS) is defined as a congenital (present at birth) malformation involving the cerebellum and the cavity in the brain called the fourth ventricle. (The fourth ventricle is an area that allows cerebrospinal fluid to flow freely through the brain and spinal column.) In cases of DWS, there is usually an accompanying cyst at the base of the skull and enlargement of the fluid spaces in the brain. This increase in space allows more fluid to accumulate, causing pressure to increase in the skull.

This syndrome may or may not be detectable by ultrasound before birth. Some children are born with overt symptoms that may lead to the diagnosis of DWS, including increased head circumference; a bulge at the back of the head; poor eye control; or anomalies of the heart, feet, limbs, or hands. For some the diagnosis may come later as parents and the pediatrician become aware of symptoms.

The important thing to manage is the increase in pressure (hydrocephalus) on the brain, usually by having a shunt (a small tube) placed to keep the fluid levels normal inside the skull.

DWS can have varying effects on cognitive development and, depending on how severe the physical complications are, it can sometimes shorten the child's life span. Support, counseling, and intervention are key to optimizing the outcome.

For more resources on DWS, check out:

• The National Institutes of Health Dandy-Walker syndrome information page
• Several Dandy-Walker syndrome support groups