Dandy Walker Syndrome: Symptoms, Causes, Treatments

The disease or Dandy Walker syndrome (SDW) is a congenital anomaly that usually develops during childhood and is characterized by the presence of hydrocephalus, alterations in areas of the cerebellum and cystic dilation of the fourth ventricle, which produces a widening of the posterior fossa (Rodríguez Virgili and Cabal García, 2010).

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

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

In some older children, symptoms related to intracranial hypertension, irritability, vomiting, convulsions, instability, lack of muscle coordination or spasmodic movements may occur (Dandy-Walker Alliance, 2009).

Dandy Walker Syndrome

In addition, this type of pathology is associated with alterations in other areas of the central nervous system, such as the absence of the corpus callosum and / or cardiac, facial malformations, and in the upper and lower extremities (Dandy-Walker Alliance, 2009).

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 Dandy-Walker syndrome (SDW)

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

The cerebellum, is one of the brain structures with greater dimension that is part of our nervous system. It represents approximately 10% of the brain weight and can contain approximately more than half of brain neurons.

Traditionally, it has been assigned 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 , has been highlighted .

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

In addition, in one of the cavities that are filled with fluid between the brainstem and the cerebellum (fourth ventricle) and the area of ​​the skull that contains the cerebellum and brainstem (posterior fossa), an abnormal widening can be observed (US National Library of Medicine, 2015).

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

Statistics

In the United States, it has been estimated that the frequency of malformation or Dandy-Walker syndrome (SDW) is 1 chaos of 25,000-30,000 (National Organization for Rare Disorders, 2008).

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

Symptom

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 (García-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. (Rodríguez Virgili and Cabal García, 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 (Rodríguez Virgili and Cabal García, 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).

In addition, it has been observed that more than half of the individuals affected by this pathology present some kind of intellectual alteration, from mild to severe, while other individuals despite presenting an intellectual level within the expected normative intervals, can present serious difficulties of learning (US National Library of Medicine, 2015).

With regard to the generalized delay of development, it is common to observe a delay in the development of motor skills, particularly in crawling, branding or movement coordination (US National Library of Medicine, 2015).

Regarding muscle tone, in many cases they may experience muscle stiffness or weakness, or partial paralysis of the lower extremities (US National Library of Medicine, 2015).

In addition, the condition of Dandy-Walker syndrome is not only associated with alterations in the brain, problems related to chondrocal defects, abnormalities in utogenital treatment, alterations or malformations in the fingers and toes, and / or easy traits are also described. abnormal (US National Library of Medicine, 2015).

As we noted earlier, not in all cases the clinical course begins to manifest itself 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, 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) García-Caballero, 2012):

  • Congenital alterations related to the central nervous system : dysgenesis of the corpus callosum, holoproscenfalia, dysplasia of the cingulate gyrus, macrocephaly, spina bifida, lumbosacral meningocele.
  • Congenital disorders not associated with the central nervous system : orofacial and palatal malformations, cardiac anomalies, polycystic kidneys, retinal dysgenesis, Meckel-Gruber syndrome.
  • Syndromes related to SDW : 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

The Dandy-Walker syndrome (SDW) is a congenital disease (Rodríguez Virgili and Cabal García, 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, highly influenced by environmental factors.

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 represent 40% of infant deaths during the first moments of life, in addition this type of anomalies are an important cause of impairment of functionality in the child population, give rise to a wide variety of neurological disorders (Herman-Sucharska et al, 2009).

In the case of Dandy-Walker syndrome, developmental defects have been associated with the occurrence of chromosomal abnormalities: deletion of chromosome 3q24.3, 6p25, 13q32.2-q33.2 or the duplication of 9q (National Organization for Rare Disorders , 2008).

Specifically, Dandy-Walker syndrome occurs most frequently in individuals who have a trisomy on chromosome 18, 23, 21 or 9 (US National Library of Medicine, 2015).

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 appears 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 etiological cause clearly defined and 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

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 is usually detected by chance after conducting clinical studies related to the posterior fossa (Rodríguez Virgili and Cabal García, 2010).

Treatment

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

Hydrocephalus is frequently approached through surgical procedures with the placement of a centriculoperitoneal shunt, or pharmacological treatment, to address the rest of the symptoms (Rodríguez Virgili and Cabal García, 2010).

Another therapeutic approach in 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).

Forecast

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

If there are very severe alterations and multiple malformations, it is likely that several systems and organs will be seriously affected, possibly resulting in death (Rodríguez Virgili and Cabal García, 2010).

On the other hand, diagnosis and prognosis is favorable when hydrocephalus and associated deficits are approached early and appropriately (Rodríguez Virgili and Cabal García, 2010).