What Is Dandy-Walker Syndrome?

Overview

Dandy-Walker syndrome is a complex and rare neurological condition characterised by a combination of abnormalities in the cerebellum, fluid-filled spaces within the brain (ventricles), and the connecting pathways between them. It is classified by dysplasia or underdevelopment of the cerebellar vermis (which joins the two hemispheres of the cerebellum), and expansion of both the fourth ventricle and posterior fossa (the space behind the cerebellum).^1,2,3 It affects approximately 1 in every 25,000-30,000 births and presents various cognitive, motor, and developmental challenges.² Compared to other conditions such as hydrocephalus, behavioural disorders, spine diseases, and trauma, Dandy-Walker syndrome is relatively rare.¹ Prenatal diagnosis and genetic testing are essential in identifying and managing this rare syndrome.² 

This article will delve into the causes of Dandy-Walker syndrome, explore its signs and symptoms, discuss management and treatment options, provide insights into the diagnosis process, and address frequently asked questions surrounding this condition. After reading this article, readers should be equipped with a better understanding of Dandy-Walker syndrome and its implications for affected individuals and their families.

Causes of dandy-walker syndrome

The exact factors contributing to the development of Dandy-Walker Syndrome are not yet fully understood, but it is widely accepted that a combination of genetic and environmental influences play a role.^1,2 Researchers have observed genetic mutations and chromosomal abnormalities in association with the syndrome.³ Maternal viral infections, such as rubella and toxoplasma, as well as alcohol consumption, have also been suggested as possible risk factors.⁴ 

Studies have reported a causal relationship between chromosomal abnormalities and malformation syndromes.³ Specifically, chromosomal abnormalities on chromosomes 3, 9, 13, and 18 have been associated with Dandy-Walker Syndrome. An extra copy of chromosome 18 is the most common chromosomal abnormality associated with Dandy-Walker syndrome. An extra copy of chromosome 13 has been reported in a small number of Dandy-Walker syndrome cases, as well as extra copies and parts of chromosome 9. Chromosome 3 abnormalities, specifically deletions on the ZIC1 and ZIC4 genes, have also been associated with Dandy-Walker syndrome.³

Although significant progress has been made in identifying these genetic and chromosomal factors, further research is needed to understand what causes the syndrome.

Signs and symptoms of dandy-walker syndrome

Dandy-Walker syndrome shows a variety of symptoms among affected individuals. The characteristic features of Dandy-Walker syndrome include:

• Cranial abnormalities, such as an enlarged skull
• Extracranial abnormalities, such as heart, kidney, and bowel problems
• Neurological anomalies, such as delayed development of motor skills and learning problems
• Hydrocephalus (excess fluid in the brain)
• An enlarged posterior fossa 
• An enlarged fourth ventricle
• Underdevelopment or absence of the cerebellar vermis.^2,3 

Clinical aspects of Dandy-Walker syndrome often include obstructive hydrocephalus, which can lead to cranial nerve palsies (a decrease or loss of function of one or more cranial nerves).³ Hydrocephalus is characterised by the accumulation of fluid in the brain.⁴ This fluid buildup can cause pressure on the brain and lead to various symptoms. Raised pressure in the skull may result in symptoms such as irritability, vomiting, and convulsions. Cerebellar signs, including ataxia and nystagmus (involuntary eye movement), are also commonly observed.^2,3

Developmental delays are common in individuals with Dandy-Walker syndrome. Motor coordination difficulties, including impaired coordination and balance, are also frequently observed. Intellectual disabilities, such as cognitive impairments and learning difficulties, may be present.^2,3 Vision and hearing impairments can occur, and epileptic seizures may also be present in some cases.⁴ Unsteady gait and balance issues are other common manifestations of Dandy-Walker syndrome. 

In addition, Dandy-Walker syndrome patients may exhibit symptoms outside their brain and head in 26-38% of cases. These can include congenital heart defects, syndactyly (webbed or fused fingers or toes), bowel abnormalities, and kidney disorders such as the development of kidney cysts. Other presentations may include a cleft palate, macrocephaly (enlarged head), and high blood pressure.¹ It is important to note that the severity of the disease can vary widely in children with Dandy-Walker syndrome, making it unpredictable in terms of its impact on individuals. 

By understanding the range of signs and symptoms associated with Dandy-Walker syndrome, healthcare professionals and caregivers can better identify and address the needs of affected individuals, providing them with the necessary support.

Management and treatment for dandy-walker syndrome

The management of Dandy-Walker syndrome is tailored to the individual's specific needs and depends on the severity of symptoms and any associated health conditions. 

One common treatment for Dandy-Walker syndrome is the insertion of a shunt to manage hydrocephalus. This involves diverting excess cerebrospinal fluid through a surgically implanted tube, helping to reduce pressure on the brain. Regular monitoring of the shunt function is necessary to ensure its effectiveness.¹

In addition to medical interventions, physical and occupational therapy play crucial roles in managing Dandy-Walker syndrome. These therapies focus on addressing motor coordination difficulties and developmental delays. Through targeted exercises and activities, individuals with Dandy-Walker syndrome can improve their motor skills and enhance overall physical functioning.⁵ 

Cognitive and academic challenges associated with Dandy-Walker syndrome may require special education programs and therapies. These interventions aim to support individuals in their learning and cognitive development, helping them overcome intellectual disabilities and reach their full potential. 

It is important to regularly monitor and manage associated health conditions that may arise in individuals with Dandy-Walker syndrome. For example, if seizures occur, appropriate medication and seizure management techniques may be implemented. Similarly, vision and hearing impairments may require ongoing assessment and intervention by specialists in those fields. 

It is worth noting that in some cases, particularly in older children, a surgeon may remove or create a hole in, any blocking cysts or membranes that may be causing fluid build-up.¹ This surgical procedure aims to address specific obstructions and can be a viable option in certain situations. 

Overall, the management of Dandy-Walker syndrome involves a comprehensive approach that combines medical interventions, therapy, and supportive measures.

FAQs

How can I prevent dandy-walker syndrome?

Although there are currently no known specific preventive measures for Dandy-Walker syndrome due to its rarity, there are steps to reduce potential risk factors. Good prenatal care is crucial to ensure the well-being of both the mother and the developing foetus. This includes regular prenatal check-ups, proper nutrition, and following healthcare provider recommendations. Genetic counselling can be particularly valuable for individuals with a family history of Dandy-Walker syndrome or those who have had previous pregnancies affected by the condition.

How common is dandy-walker syndrome?

Dandy-Walker syndrome is a rare condition, with reported incidence rates varying due to its uncommon nature. It is estimated to occur in approximately 1 in every 25,000-30,000 live births.¹ However, it is important to note that these incidence rates may vary slightly across different populations and geographic regions.

Who is at risk of dandy-walker syndrome?

Certain factors can increase the risk of developing Dandy-Walker syndrome, such as specific genetic mutations and alterations to chromosomes.  Family history also increases the likelihood of passing on the syndrome. However, the condition can still occur without known risk factors. Further research is needed to understand the interplay of genetics and environment and to identify additional risks. 

When should I see a doctor?

If you notice any symptoms or developmental delays in your child, seek medical attention for early identification of Dandy-Walker syndrome. Regular prenatal and postnatal screenings are crucial for monitoring the baby's health and detecting potential issues like Dandy-Walker syndrome. 

Summary

Dandy-Walker syndrome is a rare neurological condition characterised by abnormalities in the cerebellum and ventricles of the brain. It presents various cognitive, motor, and developmental challenges, and genetic and chromosomal abnormalities are believed to contribute to its development. Early diagnosis and intervention are crucial in managing the condition. Treatment involves a multidisciplinary approach, including shunt insertion, therapy, and supportive measures. Regular screenings and seeking medical attention concerning symptoms are important. Understanding the condition's causes and seeking timely care can optimise outcomes for affected individuals.