Dandy Walker Syndrome: Symptoms, Types, Causes and Treatment

Dandy Walker Syndrome (DWS) is a rare and complex congenital brain disorder, most well-known for its effects on the cerebellum and the fluid-filled spaces within the brain. Named after neurologists Walter Dandy and Arthur Walker, this syndrome can present a wide spectrum of challenges, from mild motor delays to severe neurological impairments. Understanding DWS is crucial not only for affected individuals and their families but also for healthcare providers seeking to improve diagnosis, management, and outcomes. In this article, we’ll explore the symptoms, types, causes, and modern treatment options for Dandy Walker Syndrome, synthesizing the latest evidence from scientific literature.

Symptoms of Dandy Walker Syndrome

Dandy Walker Syndrome can manifest in a variety of ways, ranging from subtle developmental delays to pronounced neurological and physical symptoms. Early recognition of these signs can be pivotal for timely intervention and improved outcomes.

Symptom	Description	Frequency/Severity	Source
Macrocephaly	Enlarged head/skull due to fluid buildup	Common; often progressive	1 2 5
Motor Delay	Slowed development of movement and coordination	Frequent in infancy	1 2 4
Hydrocephalus	Accumulation of cerebrospinal fluid in the brain	Present in most cases	1 2 9
Seizures	Episodes of abnormal electrical activity in the brain	Variable occurrence	2 12
Spasticity	Muscle stiffness or involuntary movements	Sometimes present	2 5
Cognitive Delay	Learning or intellectual disability	Ranges from mild to profound	4 10 12
Psychiatric Symptoms	Mood or behavioral disorders (e.g. bipolar)	Rare, but reported	4
Respiratory Issues	Apnea or respiratory failure	Occasionally present	2

Table 1: Key Symptoms

Understanding the Symptom Spectrum

Dandy Walker Syndrome’s symptoms are diverse, reflecting the complexity of the underlying brain malformations.

Neurological and Physical Signs

• Macrocephaly is often the first visible sign, where the infant’s head enlarges due to increased intracranial pressure from excess cerebrospinal fluid (hydrocephalus) 1 2 5. This may be noticed by parents or during routine pediatric check-ups.
• Motor delays are also prominent. Babies may be slow to hold their heads up, sit, crawl, or walk—milestones that are closely monitored in early development 1 2.
• Hydrocephalus—present in the majority of DWS cases—can further contribute to symptoms like vomiting, irritability, or sunsetting of the eyes (a downward gaze due to pressure effects) 2 5 9.

Cognitive and Behavioral Impact

• Cognitive delays and intellectual disabilities are common but can range widely, even in the same family. Some children experience only mild learning difficulties, while others may have more significant impairment 4 10 12.
• Seizures and spasticity may develop, adding to the need for multidisciplinary care 2 12.
• Psychiatric and behavioral symptoms, such as attention deficits or mood disorders (including rare cases of bipolar disorder), have been reported, highlighting the cerebellum’s role beyond motor coordination 4.

Systemic and Secondary Symptoms

• Respiratory issues (like apnea) and, in severe cases, respiratory failure can occur, particularly when brainstem structures are affected by pressure from cysts or hydrocephalus 2.
• Vision and hearing problems are less common but can appear, especially when DWS is associated with other congenital anomalies 12.

Overall, the presentation is highly variable, and severity often depends on whether DWS is “isolated” or accompanied by additional brain or systemic malformations 7 10.

Types of Dandy Walker Syndrome

Dandy Walker Syndrome is not a single entity but a spectrum known as the Dandy Walker complex. Proper classification is vital for diagnosis, management, and prognosis.

Type	Key Features	Severity/Associations	Source
Dandy-Walker Malformation	Vermis agenesis/hypoplasia, large posterior fossa, cystic 4th ventricle	Most severe, often with hydrocephalus	8 10
Dandy-Walker Variant	Partial vermis hypoplasia, cystic 4th ventricle, normal fossa	Milder, variable prognosis	8 14
Mega Cisterna Magna	Enlarged cisterna magna, normal vermis and 4th ventricle	Usually benign, incidental	8 14
Posterior Fossa Arachnoid Cyst	Cyst in posterior fossa, normal cerebellum/vermis	Usually mild, may cause symptoms	8

Table 2: Dandy Walker Complex Types

Breaking Down the Types

Dandy-Walker Malformation (Classic)

• Characterized by complete or partial agenesis (absence) or hypoplasia (underdevelopment) of the cerebellar vermis, a cystic dilatation of the fourth ventricle, and an enlarged posterior fossa 8 10.
• Most severe form, frequently associated with hydrocephalus and other congenital anomalies.
• Early intervention is often required due to rapid progression of symptoms 8 10.

Dandy-Walker Variant

• Features partial vermian hypoplasia and cystic changes in the fourth ventricle, but the posterior fossa is usually of normal size 8 14.
• Considered milder, but symptoms can overlap with the classic form.
• Prognosis is variable and often better if unaccompanied by additional malformations 8 14.

Mega Cisterna Magna

• Defined by an enlarged cisterna magna (the space behind the cerebellum), with normal cerebellar and ventricular anatomy 8 14.
• Typically, there are no neurological symptoms; it is often discovered incidentally during imaging for unrelated reasons.

Posterior Fossa Arachnoid Cyst

• Cystic lesion within the posterior fossa but with a normal cerebellum and fourth ventricle 8.
• Can cause symptoms similar to hydrocephalus if the cyst is large enough to compress adjacent structures.

Clinical Implications

• Accurate differentiation between these types is crucial because it affects both prognosis and treatment choices.
• Modern imaging, such as MRI and CT, is indispensable for classification and surgical planning 2 8 9.

Causes of Dandy Walker Syndrome

Despite over a century of research, the exact causes of Dandy Walker Syndrome remain incompletely understood. However, significant progress has been made in identifying genetic and environmental risk factors.

Cause Type	Description	Implications/Notes	Source
Genetic	Chromosomal abnormalities (e.g., trisomy 18, 3, 9, 13)	Often associated with other malformations	6 7 11
Environmental	Maternal infections, diabetes, teratogens	May interact with genetic risk	2 7 11
Multifactorial	Combination of genes and environment	Most cases considered multifactorial	2 7 11
Placental/Umbilical	Abnormalities of placenta or umbilical cord	May play a role in some cases	11

Table 3: Summary of Causes

Delving Into the Causes

Genetic Factors

• Chromosomal abnormalities are frequently observed in DWS, including trisomy 18, and less commonly in chromosomes 3, 9, and 13 6 7.
• Syndromic forms of DWS are often accompanied by other CNS or systemic malformations, such as congenital heart disease or facial anomalies 10 11.
• Isolated DWS (without other anomalies) generally has a better prognosis compared to DWS with chromosomal or multiple malformations 7.

Environmental and Multifactorial Influences

• Maternal factors, such as infections, diabetes, or exposure to teratogens during pregnancy, have been implicated in some cases, possibly acting as environmental triggers in genetically susceptible fetuses 2 7 11.
• The multifactorial model—where both genetic predisposition and environmental exposures contribute—is currently the most widely accepted explanation for most cases 2 7.

Additional Considerations

• Rarely, placental or umbilical cord abnormalities have been observed, suggesting a possible role in the development of DWS 11.
• The timing of the insult appears to be crucial, with disruptions during early embryonic development (3rd to 4th week post-conception) affecting the formation of the cerebellum and surrounding brain structures 10.

Importance of Genetic Counseling

• Because of the genetic associations, families with a history of DWS or related anomalies are often referred for genetic counseling and, if DWS is suspected prenatally, for advanced genetic testing (karyotyping, SNP-array) 7.

Treatment of Dandy Walker Syndrome

Managing Dandy Walker Syndrome requires a multidisciplinary approach, tailored to the specific symptoms and severity in each patient. The mainstay of treatment focuses on controlling hydrocephalus and addressing associated neurological and developmental issues.

Treatment	Purpose/Indication	Outcomes/Notes	Source
Shunt Surgery	Divert excess CSF, relieve hydrocephalus	Most common, variable complications	12 13 15 16
Endoscopic Procedures	ETV, ETV+CPC to restore CSF flow	Increasingly preferred in infants/children	13 14 16
Cyst Decompression	Surgical opening or draining of cyst	Used in selected patients	5 13 15
Medical Management	Seizures, psychiatric symptoms, rehab	Supportive, symptom-based	4 12
Multidisciplinary Care	Developmental, cognitive, and rehab support	Essential for best outcomes	2 12

Table 4: Main Treatment Approaches

Surgical Interventions

Shunt Surgery

• Ventriculoperitoneal (VP) and cystoperitoneal (CP) shunts are the mainstays for managing hydrocephalus and cystic enlargement. These shunts divert cerebrospinal fluid (CSF) from the brain cavities or cysts to the abdomen, where it can be absorbed 12 13 15 16.
• Single shunt procedures (either VP or CP) are effective for most patients. However, some may require both if a single shunt does not sufficiently control both ventricular and cystic components 12 13 15.
• Shunt complications—such as malfunction, infection, or the need for revision—are not uncommon, so long-term follow-up is necessary 12 13.

Endoscopic Techniques

• Endoscopic third ventriculostomy (ETV), sometimes combined with choroid plexus cauterization (CPC), allows for restoration of CSF flow without permanent shunt placement. This is increasingly used, especially in infants with open aqueducts 13 14 16.
• ETV/CPC has shown a high rate of success in selected patients and can reduce the dependency on shunts, which are associated with lifelong risks 14.

Cyst Decompression

• In selected cases, especially when a large posterior fossa cyst causes compression or acute symptoms, surgical decompression may be required. This can be achieved through craniotomy and cyst fenestration or drainage 5 13 15.

Medical and Supportive Care

Symptom Management

• Seizures are managed with antiepileptic medications as needed 12.
• Psychiatric or behavioral symptoms (such as those seen in rare cases of bipolar disorder or attention deficits) are treated according to standard psychiatric protocols, often requiring close monitoring for medication side effects 4.

Rehabilitation and Developmental Support

• Early intervention with physical, occupational, and speech therapy is essential to maximize developmental potential, especially for those with motor or cognitive delays 2 12.
• Multidisciplinary teams, including neurologists, neurosurgeons, therapists, and educators, are key to comprehensive care.

Prognosis and Long-Term Considerations

• Prognosis varies widely and depends on the presence of associated malformations, the degree of cerebellar involvement, and the effectiveness of hydrocephalus management 2 7 10 16.
• Isolated DWS cases with no chromosomal abnormalities or additional anomalies generally have a much better outlook, both cognitively and physically 7.
• Regular follow-up for shunt function, developmental progress, and associated health concerns is necessary throughout childhood and often into adulthood.

Conclusion

Dandy Walker Syndrome is a rare but impactful congenital brain disorder with a highly variable clinical course. Advances in imaging, genetics, and neurosurgical techniques continue to improve diagnosis and outcomes. However, early recognition and individualized, multidisciplinary care remain central to achieving the best prognosis for affected children and their families.

Key Points:

• Dandy Walker Syndrome involves cerebellar and ventricular malformations, most often presenting with hydrocephalus, motor delay, and macrocephaly 1 2 5.
• The Dandy Walker complex includes several types, ranging from classic malformation to less severe variants and cystic forms 8 14.
• Causes are multifactorial, with both genetic (chromosomal abnormalities) and environmental factors playing roles 6 7 11.
• Treatment is primarily surgical (shunt placement, endoscopy), with supportive therapies addressing seizures, developmental, and psychiatric needs 12 13 14 16.
• Prognosis depends on the severity of malformations and the presence of associated anomalies; isolated cases without genetic defects fare best 7 10 16.

With continued research and interdisciplinary care, the outlook for individuals with Dandy Walker Syndrome continues to improve, offering hope for better quality of life and developmental outcomes.