Dayton Children’s Hospital

Dandy-Walker Malformation

What is Dandy-Walker malformation?

Dandy-Walker malformation, also known as Dandy-Walker syndrome , is a condition that affects development of the cerebellum, which is the part of the brain that coordinates movement, posture, speech, and balance. It is sometimes associated with hydrocephalus, which is the build-up of too much cerebrospinal fluid in the brain.

The exact cause of Dandy-Walker malformation is unknown; it is a congenital condition, which means it is present at birth. 

How is Dandy-Walker malformation diagnosed ?

Dandy-Walker malformation (DWM) is easily seen with obstetrical ultrasound and is usually diagnosed by 20 weeks’ gestation, but has been seen even earlier. The findings on ultrasound consist of a cyst in the cerebellum. There may or may not be other birth defects in the brain or in other organ systems. It is very important to have your fetus evaluated by a physician experienced with DWM, such as a Maternal-Fetal Medicine specialist in order to determine the extent of the birth defect(s). The outcomes are generally expected to be better when there is an isolated Dandy-Walker malformation without other birth defects. If there are other birth defects, your physician may recommend additional testing such as an amniocentesis. Often Maternal-Fetal Medicine specialists will order a fetal MRI to better image the fetal brain. DWM is not treated prior to delivery.

In the majority of babies, symptoms of Dandy-Walker malformation occur during the first year of life, and may include:

  • Increasing head size (due to hydrocephalus)
  • Intellectual disabilities
  • Delayed development of motor skills (e.g., crawling, walking)
  • Muscle stiffness
  • Leg paralysis
  • Seizures
  • Hearing or vision problems

After delivery, additional tests may be done to confirm the diagnosis. Common tests for may include:

  • Ultrasound
  • Magnetic resonance imaging (MRI)
  • Computed tomography (CT)

How is Dandy-Walker malformation treated?

There is no specific treatment for Dandy-Walker malformation. Treatments are aimed at resolving the associated problems (for example, physical therapy is used to improve motor skills, special education can help improve intellectual abilities). In some cases, your physician may recommend surgery to insert a tube (shunt), which redirects the cerebrospinal fluid to another area of the body where it can be absorbed.

How will Dandy-Walker malformation affect my baby during and after surgery?

During the surgery to insert a shunt, your baby will be given general anesthesia, which means the baby will be sleeping. After surgery, your baby will need to stay in the hospital for between two and four days.

Once a shunt has been inserted, it is permanent, so your child will require lifelong monitoring. At some point, the shunt may become blocked. Surgeons may or may not be able to reopen it without having to replace it. Sometimes other shunt-related problems may occur, including kinking, tube separation, excess drainage or infection.