What is Dandy Walker Syndrome?

Dandy-Walker Syndrome is a congenital brain defect that causes impaired brain formation. It is congenital which means the baby is born with the condition and it happens as the baby develops during pregnancy.

The Dandy Walker affects the cerebellum and its surrounding spaces. The cerebellum is located at the back of the brain, next to the brain stem. It is part of the central nervous system. The cerebellum coordinates movement. It also allows you to control:

Balance, coordination and posture.
Vision.
Thinking abilities.
Motor skills.
Behavior.

What happens to people's brains with Dandy Walker?

With Dandy-Walker syndrome, several conditions can occur:

The fourth ventricle is enlarged. This space around the cerebellum facilitates the circulation of cerebrospinal fluid between the upper and lower brain and spinal cord.
The cerebellar vermis (the area between the two hemispheres or halves of the cerebellum) is partially or completely absent.
A cyst (fluid-filled sac) forms near the fourth ventricle.
The base of the skull (posterior cranial fossa) is enlarged.
Hydrocephalus can occur if cerebrospinal fluid builds up, causing high blood pressure and swelling of the skull.

What causes Dandy-Walker syndrome?

The Dandy Walker occurs when there is a problem with the development of the baby's cerebellum in the womb. In some cases, the disease can be caused by a genetic mutation.

Some people with Dandy-Walker syndrome have chromosomal disorders, such as extra or missing pieces of chromosomes. Chromosomes are bundles of DNA that carry genes. Dandy-Walker syndrome can also occur as part of a genetic condition that includes multiple birth defects.

Other potential causes of Dandy Walker may include:

Some viruses that are passed from biological parent to child during pregnancy.
Exposure to certain toxins or medications during pregnancy.
Biological parent was diabetic.

When do Dandy Walker symptoms appear?

Sometimes symptoms appear suddenly and abruptly. In other cases, the symptoms may manifest in such a way that parents do not notice that something is wrong.

Symptoms usually develop during the first few months of a child's life, but some children are not diagnosed until they are 3 or 4 years old.

What are the symptoms of Dandy-Walker Syndrome?

Symptoms in infants include:

Meeting motor milestones later than expected (developmental delays).
Disproportionately large skull.
Low muscle tone (hypotonia).
Stiff muscles (spasticity).

Symptoms in older children include:

Vomiting, convulsions and irritability are signs of increased pressure on the brain.
Uncoordinated movements, unstable or jerky eye movements - signs of diseases of the cerebellum.

Other signs include:

A bulge or swelling at the back of the skull.
Conditions with nerves that control the neck, face and eyes.
Unusual breathing rate.
Convulsions.
Limited intellectual abilities.
Symptoms of hydrocephalus.

What is the difference between Dandy-Walker Complex and Dandy-Walker Syndrome?

The Dandy-Walker complex is a group of disorders with similar symptoms. Dandy-Walker syndrome is one of the disorders included in the Dandy-Walker complex.

Other disorders included in the Dandy-Walker complex:

Isolated cerebellar vermis hypoplasia or Dandy-Walker variant: the cerebellar vermis is small or underdeveloped. Children's brains do not have other structural problems associated with Dandy-Walker syndrome. Many children with this diagnosis develop normally.
Mega cisterna magna: The posterior cranial fossa is large, but the cerebellum is typical. Mega cisterna magna often causes no health problems.
Posterior fossa arachnoid cyst: the cyst develops in the posterior cranial fossa. Children rarely develop symptoms due to the presence of a cyst.

What other disorders are associated with Dandy-Walker Syndrome?

Children with Dandy-Walker may have disorders in other parts of the central nervous system, including:

-Absence of the corpus callosum, a rare congenital disorder in which part of the brain is missing from the baby.

-Problems with the shape of the limbs, face, heart, fingers and toes.

Will my child have mental retardation?

Less than half of the children with Dandy-Walker have mental retardation. Mental retardation most often occurs in children with Dandy-Walker syndrome, who also have:

Severe hydrocephalus.
Chromosomal conditions.
Other congenital conditions.

How is Dandy-Walker syndrome diagnosed?

Doctors or parents may notice that a child has increased head size. A child may also not meet developmental milestones. Doctors order brain imaging to diagnose Dandy-Walker. Tests may include:

Ultrasound.
Computed Tomography.
MRI.

Occasionally, doctors diagnose this condition before a baby is born during a prenatal ultrasound or fetal MRI.

Should my family get genetic testing if the child has Dandy Walker disease?

If you have a child with a Dandy-Walker malformation, talk to your doctor about genetic counseling. A small percentage of people with the condition have family members who also have it. Since there may be a genetic component, many physicians recommend genetic testing.

What are the treatment options for Dandy-Walker Syndrome?

Treatment is based on the symptoms of Dandy-Walker syndrome. Before starting treatment, a thorough evaluation by a physician is necessary. For example, doctors may recommend:

Ventriculoperitoneal shunt: Surgeons place a ventriculoperitoneal shunt, a small device, to drain excess fluid from the brain. A shunt can reduce pressure on the brain and improve symptoms.
Medications: Your child's doctor may prescribe medications to control seizures.
Therapy: Physical and occupational therapy can help children maintain muscle strength. Therapists can also teach children new ways to do their usual activities. Speech therapy can help develop language and speech.
Special Education: A good learning environment can help children achieve their educational and social goals.

Can Dandy-Walker Syndrome be Prevented?

It is not known how to prevent Dandy-Walker syndrome. Consistent prenatal care gives you the best chance of a healthy pregnancy. Follow your doctor's recommendations for a healthy lifestyle during pregnancy.

People with this disease have a wide range of experiences. Some have minor symptoms. Others have a profound disability. Some children can achieve typical cognitive abilities with the right treatment plan. Others don't, even when their healthcare team diagnoses and treats the disease early.

How can I take care of my child with Dandy-Walker?

Early intervention can help your child get the best chance of treatment success. If you notice that your child is not reaching certain developmental milestones on time, such as being unable to sit, walk, or talk, see your doctor. They can make an accurate diagnosis so your child can receive the most effective treatment plan.

Your Dandy-Walker child care team may include: