Dandy-Walker Syndrome Life Expectancy

Dandy-Walker syndrome (also called Dandy-Walker malformation) is a condition in which part of the brain doesn't form fully before birth. The middle part of the cerebellum (the vermis) is small or missing, and a fluid-filled space at the back of the brain (the fourth ventricle) is enlarged into a cyst. It affects about 1 in 25,000 to 35,000 babies.

There's no single life expectancy for Dandy-Walker syndrome. Outlook ranges from a near-normal life to serious disability or early death, depending mostly on hydrocephalus and on whether there are other differences in the brain or body.

What affects the outlook

Hydrocephalus and how it's treated. Most people with Dandy-Walker syndrome develop hydrocephalus, a build-up of fluid that raises pressure inside the head, usually within the first few months of life. Untreated, hydrocephalus is very serious. Treatment, usually a shunt (a thin tube that drains fluid to the abdomen) or sometimes an endoscopic procedure, greatly improves survival. Problems linked to hydrocephalus or its treatment, such as shunt blockage or infection, are the most common cause of death.

Other brain differences. Children whose only difference is a partly underdeveloped vermis often do well and may develop normally. Those with more extensive brain malformations, such as an absent corpus callosum, are more likely to have significant developmental and neurological problems.

Differences elsewhere in the body. Some children also have heart defects, kidney or genital differences, extra or fused fingers or toes, cleft palate or a chromosome condition. Babies with problems in two or more body systems have the lowest survival.

Breathing control. Rarely, severe hydrocephalus affects the brainstem centres that control breathing.

What life is like

Development varies widely:

• Motor skills: delays in sitting, crawling and walking, low muscle tone, and problems with balance and coordination are common.
• Learning: fewer than half of children have an intellectual disability, and it's most likely in those with severe hydrocephalus or other malformations. Others have normal intelligence, though some have specific learning difficulties.
• Seizures: affect roughly 15 to 30% of people.
• Other problems may include vision or hearing difficulties, and later muscle stiffness.

Physiotherapy, occupational therapy, speech and language therapy and educational support help children reach their potential.

When symptoms appear

In most people, signs are present at birth or appear in the first year: a rapidly growing head, a bulging soft spot, irritability, vomiting, or slow motor development. The condition is also often found on a pregnancy scan from about 18 to 20 weeks. In about 10 to 20% of people, symptoms don't appear until later childhood or adulthood, typically headaches, unsteadiness or other signs of raised pressure. Occasionally it's found by chance on a scan in someone with no symptoms at all.

Life expectancy in summary

• Milder forms with treated or no hydrocephalus and no other malformations: many people live into adulthood, and some have a near-normal life.
• More severe forms, or with major heart, chromosome or other brain differences: a higher risk of serious disability and of death in infancy or childhood.
• Throughout life: people with shunts need lifelong follow-up, because shunts can block or become infected. Seek urgent help for headache, vomiting, drowsiness, a bulging soft spot in a baby, or any sudden change.

A child's neurosurgeon and neurologist are best placed to explain what is likely in their particular case. See also Dandy-Walker prognosis and treatment.

This page is for general information and isn't a substitute for advice from your child's medical team.