Authors: Mekka Garcia, MD, NYU Grossman School of Medicine 
Alison L. Christy, MD, PhD, Providence Pediatric Neurology at St. Vincent Medical Center – Portland, Oregon

Reviewed: September 2021

SUMMARY

Dandy-Walker malformation (DWM) is a rare brain abnormality. It affects the cerebellum, the back part of the brain. This back part of the brain is important for voluntary movement, balance, and coordination. Most children with DWM have delays in motor development. They may take more time learning to crawl or walk. 

In severe cases, DWM can lead to problems with the flow of a fluid in the brain called cerebrospinal fluid (CSF). A buildup of CSF in the brain leads to a condition called hydrocephalus. Children with a buildup of CSF may have macrocephaly, a very large head. 

DWM is congenital. This means it is something a child is born with, not something that appears later in childhood. DWM can be diagnosed during pregnancy. There is no cure for DWM, but supportive care is available.

Disorder Overview

DESCRIPTION 

The posterior fossa is the back compartment of the brain. The cerebellum sits in it, behind the fourth ventricle. Ventricles are normal pockets in the brain. They hold cerebrospinal fluid (CSF). 

DWM includes three distinct brain structure differences:

1. The middle part of the cerebellum is missing or smaller in size
2. The posterior fossa is bigger than normal
3. The fourth ventricle is too large

Dandy-Walker Syndrome

Some children have DWM without any other abnormalities. However, many do have other abnormalities. They can affect:

• The brain
• The heart
• Arms and legs
• Organs in the gut

Dandy-Walker syndrome (DWS) is the term used when other abnormalities accompany DWM.

Associated Issues

Sometimes, problems due to DWM can block the flow of CSF around the brain. This can lead to:

• Macrocephaly (a large head)
• Hydrocephalus (an increase in fluid pressure around the brain)

SIGNS AND SYMPTOMS 

DWM may cause no symptoms at all. In rare cases, DWM is found on an MRI in a person with no symptoms. However, most children diagnosed with DWM will have delays in development and macrocephaly.

Symptoms at birth or shortly after birth may include:

• Macrocephaly (an unusually large head)
• Irritability
• Vomiting
• Low muscle tone (floppiness)
• Seizures (bursts of electrical activity in the brain that can cause the body to behave abnormally)
• Delays in motor skills, such as crawling, sitting, walking

Symptoms in older children may include:

• Ataxia (an unsteady gait)
• Headache
• Abnormal vision (double vision)
• Intellectual disability

Dandy-Walker syndrome (DWS) is the term used when DWM occurs alongside other abnormalities in the body. These can include:

• Cardiac differences.
  • Ventricular septal defect (a hole in the heart)
  • Pulmonary stenosis (a small vein leading to the heart)
• Horseshoe kidney.
• Cleft palate.
• Differences in extremities. 
  • Abnormal leg or arm lengths
  • Fingers or toes that are stuck together 

CAUSES

DWM occurs because of problems during fetal development. These problems usually take place during the second trimester of a pregnancy. However, this does not mean that a pregnant mother did something to cause the malformation. 

Some possible causes are:

DIAGNOSIS AND LABORATORY INVESTIGATIONS

DWM can be diagnosed in a fetus during pregnancy. This can be done using an ultrasound. An ultrasound takes pictures of the body parts of the fetus, including the brain.

After birth, magnetic resonance imaging (MRI) can be used to confirm the diagnosis. MRI takes pictures of the brain. It can look for signs of the three main structural changes signaling DWM. 

TREATMENT AND THERAPIES

There is no cure for DWM. However, therapies can treat symptoms and provide supportive care. Therapies include:

OUTLOOK

The life expectancy of people with DWM depends on the presence and severity of hydrocephalus and other associated issues. Most children with DWM live to adulthood.

Research 

ClinicalTrials.gov for Dandy-Walker Malformation (birth to 17 years) 

These are clinical trials that are recruiting or will be recruiting. Updates are made daily, so you are encouraged to check back frequently.   

ClinicalTrials.gov is a database of privately and publicly funded clinical studies conducted around the world. This is a resource provided by the U.S. National Library of Medicine (NLM), which is an institute within the National Institutes of Health (NIH). Listing a study does not mean it has been evaluated by the U.S. Federal Government. Please read the NLM disclaimer for details.   

Before participating in a study, you are encouraged to talk to your health care provider and learn about the risks and potential benefits.  

The information in the CNF Child Neurology Disorder Directory is not intended to provide diagnosis, treatment, or medical advice and should not be considered a substitute for advice from a healthcare professional. Content provided is for informational purposes only.  CNF is not responsible for actions taken based on the information included on this webpage. Please consult with a physician or other healthcare professional regarding any medical or health related diagnosis or treatment options. 

Alexiou GA, Sfakianos G and Prodromou N. Dandy-Walker malformation: Analysis of 19 cases. Journal of Child Neurology. 2010; 25(2):188-191. https://doi.org/10.1177/0883073809338410 

Bosemani T, Orman G, Boltshauser E, et al. (2015). Congenital abnormalities of the posterior fossa. RadioGraphics. 35:200-220. https://doi.org/10.1148/rg.351140038 

Dandy-Walker Alliance. https://www.dandy-walker.org 

The Journal of Child Neurology, 2021. NICU series with Dr. Sonika Agarwal: Dandy Walker malformations. [podcast] SAGE Neuroscience and Neurology.

https://sageneuroscience.sage-publications.libsynpro.com/jcn-nicu-series-dandy-walker-malformations 

National Organization for Rare Disorders. Dandy Walker Malformation. https://rarediseases.org/rare-diseases/acute-disseminated-encephalomyelitis 

Stambolliu E, Ioakeim-Ioannidou M, Kontokostas K, et al. The most common comorbidities in Dandy-Walker syndrome patients: A systemic review of case reports. Journal of Child Neurology. 2017; 32(10):886-902. https://doi.org/10.1177/0883073817712589