Last Updated on April 13, 2023 by Mike Robinson

According to estimates in the United States, the frequency of malformations or Dandy-Walker syndrome (SDW) is 1 in 25,000–30,000 (National Organization for Rare Disorders, 2008). According to estimates in the United States, the frequency of malformations or Dandy-Walker syndrome (SDW) is 1 in 25,000–30,000 (National Organization for Rare Disorders, 2008).ndy Walker syndrome (SDW) is a birth defect that usually shows up in childhood. Hydrocephalus, changes in some parts of the cerebellum, and cystic dilation of the fourth ventricle are all signs of it. Because of this, the posterior fossa grows (Rodrguez Virgili and Cabal Garca, 2010).

This alteration receives some other names, such as “malformation of Dandy Walker,” “deformity,” “cyst,” “malformation of Luschka and Magendie,” etc. (Garca Caballero, 2012).

The main signs and symptoms, which tend to appear during early childhood, are slow motor development and abnormal growth of the skull (Dandy-Walker Alliance, 2009).

Intracranial hypertension can cause irritability, vomiting, convulsions, instability, muscle coordination issues, and spasmodic movements in older children.

This pathology also affects the corpus callosum, cardiac malformations, and the upper and lower extremities.

With regard to prognosis and treatment, interventions focus on treating associated disorders and problems: reducing intracranial pressure, controlling associated deficits, treating cardiac malformations, etc. (National Institute of Neurological Disorders and Stroke, 2014).

Characteristics of SDW

Dandy-Walker syndrome is a type of malformation that affects the brain during embryonic development, mainly the development of the cerebellum (US National Library of Medicine, 2015).

The cerebellum is one of the larger brain structures that are part of our nervous system. It represents approximately 10% of the brain’s weight and can contain approximately more than half of the brain’s neurons.

Traditionally, it plays a prominent role in the execution and coordination of motor acts and the maintenance of muscle tone for balance control due to its position close to the main motor and sensory pathways.

In addition, its participation in complex cognitive processes, such as executive functions, learning, memory, visuospatial functions, or even contributing to the emotional sphere and linguistic area is obvious .

In people suffering from this disease, several parts of the cerebellum may develop abnormally: the most central part, the vermis, may present a very small volume, assume an abnormal position, or even be absent. On the other hand, both hemispheres of the cerebellum may also be affected (US National Library of Medicine, 2015).

The fourth ventricle and posterior fossa, which contain the brainstem and cerebellum, also have abnormal widening (US National Library of Medicine, 2015).

All these alterations often result in problems with muscle coordination and movement, neurological functions, intellectual performance, and state of mind, among others (US National Library of Medicine, 2015).

Statistics

According to estimates in the United States, the frequency of malformations or Dandy-Walker syndrome (SDW) is 1 in 25,000–30,000 (National Organization for Rare Disorders, 2008).

In addition, it is more frequent in females, with a 3:1 ratio (Rodrguez and Cabal, 2010; Garca-Caballero, 2012).

Image of the brain

Symptoms

In most people with Dandy-Walker syndrome, the symptoms resulting from the abnormal development of different brain regions are present from birth or develop during the first year of life (US National Library of Medicine, 2015).

However, the clinical manifestations presented by people suffering from this type of pathology will depend on several factors (Garca-Caballero, 2012):

• the severity with which Dandy-Walker syndrome occurs.
• the associated malformations.
• the age and time of diagnosis.

In almost all cases, the characteristic symptoms usually appear during childhood: obstructive hydrocephalus, increased head circumference, muscular dystrophy, ocular alterations, etc. (Rodrguez Virgili and Cabal Garca, 2010).

On the other hand, it is also common to observe other signs of cerebellar damage such as ataxia or nystagmus, as well as seizures, hypotonia, and spasticity (Rodrguez Virgili and Cabal Garca, 2010).

Specifically, the most characteristic symptoms of Dandy-Walker syndrome include (National Organization for Rare Disorders, 2008):

• generalized delay in development.
• Intellectual deficits.
• reduction of muscle tone (hypotonia).
• accumulation of fluid at the cerebral level (hydrocephalus).
• abnormal increase in cranial perimeter (macrocephaly).
• increased cranial pressure due to the development of hydrocephalus.
• Convulsive episodes

Many of the cases of children with Dandy-Walker syndrome have an abnormal accumulation of cerebrospinal fluid in the brain ( hydrocephalus ) that may involve an increase in head size (macrocephaly) (US National Library of Medicine, 2015).

More than half of those affected by this pathology have some kind of intellectual alteration, from mild to severe, while others, despite having a normal intellectual level, have serious learning difficulties (US National Library of Medicine, 2015).

Dandy-Walker syndrome also involves chondrocal defects, utogenital abnormalities, finger and toe malformations, and easy traits. abnormal (US National Library of Medicine, 2015). (US National Library of Medicine, 2015).

As we noted earlier, the clinical course does not manifest itself in all cases in the initial moments of life. Approximately 10–20% of cases present with an initial presentation of symptoms in the last phase of the childhood stage or during adulthood (US National Library of Medicine, 2015).

The late manifestation of Dandy-Walker syndrome usually has a different clinical range: headaches, instability in the sea, facial paralysis, increased muscle tone, muscle spasms, and behavioral and cognitive alterations (US National Library of Medicine, 2015 ).

Syndromes and related alterations

Specifically, there are different anomalies and syndromes that are associated with the development of the Dandy-Walker malformation (SDW) (Garca-Caballero, 2012):

• Congenital alterations related to the central nervous system include dysgenesis of the corpus callosum, holoproscenfalia, dysplasia of the cingulate gyrus, macrocephaly, spina bifida, and lumbosacral meningocele.
• Congenital disorders not associated with the central nervous system include orofacial and palatal malformations, cardiac anomalies, polycystic kidneys, retinal dysgenesis, and Meckel-Gruber syndrome.
• Syndromes related to SDW include Aase-Smith syndrome, Aicardi syndrome, brain-coulomoscular syndrome, coffin-Siris syndrome, and Cornelia de Lange syndrome.

It is rare that people suffering from Dandy-Walker syndrome have no health problems related to this condition. Specifically, alterations related to hydrocephalus and complications associated with treatment are the most common cause of death in this type of pathology (US National Library of Medicine, 2015).

Causes of Dandy Walker Syndrome

The Dandy-Walker syndrome (SDW) is a congenital disease (Rodrguez Virgili and Cabal Garca, 2010). It occurs as a consequence of embryonic defects in the development of the cerebellum and some related structures (National Organization for Rare Disorders, 2008).

The development of the nervous system (SN) follows a very complex process that is based on a multitude of genetically programmed neurochemical events that are highly influenced by environmental factors. 

Congenital malformations

When a congenital malformation occurs at the level of the nervous system , the normal and efficient development of the cascade of events related to development is interrupted. Therefore, they will begin to develop structures and / or functions in an abnormal way, having serious consequences for the individual, both physically and cognitively.

These alterations and congenital malformations can be considered one of the main causes of fetal morbidity and mortality (Piro, Alongi et al., 2013). Different investigations have indicated that they can account for 40% of infant deaths during the first moments of life. In addition, this type of anomaly is an important cause of functional impairment in the pediatric population and gives rise to a wide variety of neurological disorders (Herman-Sucharska et al., 2009).

Many of the cases of this pathology are sporadic; that is, they usually occur in people whose family history is not related to the presence of Dandy-Walker syndrome (US National Library of Medicine, 2015).

Although a reduced percentage of cases appear related to family history, a clearly defined hereditary pattern has not been identified (Walker, US National Library of Medicine, 2015). Despite this, first-degree relatives of an individual affected by Dandy-Walker have a higher risk of developing the disease compared to the general population (US National Library of Medicine, 2015).

In all other cases in which there is no clear etiological cause related to previous chromosomal alterations, it is likely that they will develop as a consequence of other genetic alterations or environmental factors (National Organization for Rare Disorders, 2008).

Diagnosis of Dandy Walker Syndrome

To make a diagnosis of this pathology, it is common to perform different neuroimaging studies to confirm the presence of abnormalities at the cerebral level (Spanish Federation of Rare Diseases, 2016).

The diagnosis of this pathology in adulthood is rare and doctors often detect it by chance after conducting clinical studies related to the posterior fossa (Rodrguez Virgili and Cabal Garca, 2010).

Treatment

Therapeutic interventions for Dandy-Walker syndrome (SDW) focus on the treatment of clinical intensity and associated problems (Rodrguez Virgili and Cabal Garca, 2010).

Hydrocephalus is a surgical procedure with the placement of a centriculoperitoneal shunt or with pharmacological treatment to address the rest of the symptoms (Rodrguez Virgili and Cabal Garca, 2010).

Another therapeutic approach for children with Dandy-Walker syndrome focuses on applying special education, physical therapy, neuropsychological intervention, and other medical services to achieve maximum physical and intellectual development (National Organization for Rare Disorders, 2008).

Outlook for Dandy Walker Syndrome

The prognosis associated with this pathology varies depending on the anomalies and related alterations (Rodrguez Virgili and Cabal Garca, 2010).

If there are very severe alterations and multiple malformations, it is likely that they will seriously affect several systems and organs, possibly resulting in death (Rodrguez Virgili and Cabal Garca, 2010).

On the other hand, diagnosis and prognosis are favorable when hydrocephalus and associated deficits get an early diagnosis. (Rodrguez Virgili and Cabal Garca, 2010).