Dandy Walker Malformation

Dandy Walker malformation is a birth defect that affects the cerebellum- the area at the back of the brain that is responsible for movement. It is estimated to affect approximately 1 out every 5,000 births.

Dandy Walker malformation causes an enlargement of the fourth ventricle, a partial or total absence of the space in between the two cerebella hemispheres and cysts by the internal base of the skull. The cysts will form during early fetal development.

A patient that has Dandy Walker malformation will not be able to drain the fluid from their brain properly, which will lead to hydrocephalus, or water on the brain. It is common for a patient to experience increased pressure of the brain, mental retardation, congenital heart problems, facial anomalies, slow motor development and a continuing enlargement of the skull.

As the child gets older, additional signs of the defect will develop. These include decreased coordination, jerky movements, convulsions, poor eye control, increased head size, breathing complications and irritability. A prenatal ultrasound can diagnose the condition. A bulge or lump on the back of the fetus' head can be seen with increased head circumference during a routine measurement check.

Because the defect is accompanied by excessive fluid in the skull, a drainage tube may need to be placed. The drainage tube will help control any pressure or swelling inside of the brain. Therapy to help with coordination and development may also be helpful.