Dandy Walker Syndrome

Dandy Walker syndrome is a congenital abnormality of the brain which affects the cerebellum and the spaces in and around the cerebellum that is composed of cerebrospinal fluid. The disorder gets its name from the founding fathers of neurosurgery, namely, Arthur Earl Walker and Walter Dandy

Dandy Walker syndrome features a partial or complete absence of that part of the brain present between the two hemispheres, bulging of the 4^th ventricle and the development of a cyst with the brain’s internal base region. Due the presence of such symptoms, the disorder is also known as Dandy Walker cyst syndrome. In addition to the above characteristics, the syndrome may also elicit other symptoms such as excessive pressure of blood supply to the brain, increased collection of cerebrospinal fluid and/or the contraction of spaces for holding fluids.

The Dandy Walker syndrome tends to affect the female population more than the male population. The disorder occurs randomly and is usually considered to be the cause for many anomalies of the central nervous system.

Symptoms of Dandy Walker syndrome

Individuals affected by this syndrome may experience a slow development of its signs and symptoms or they may elicit a sudden onset of the symptoms. Some of the symptoms of Dandy Walker syndrome are discussed below:

Infants who are afflicted by Dandy Walker syndrome may experience progressive enlargement of the skull, decreased rate of motor development and swelling of the anterior fontanelle
The affected children may also elicit a variety of symptoms such as hyper-irritability, vomiting and seizures that result from increased intracranial pressure
Children with Dandy Walker syndrome may experience odd stereotypical motor movements associated with various disorders, enuresis during nighttime, behavioral problems and hyperactivity
Adult as well as children may experience symptoms associated with cerebellar malfunction such as poor or loss of muscle coordination or ataxia, bulging of the skull from the back, imbalance, breathing pattern irregularities, ticks of the face, limbs and eyes, and an overall increase in the size and circumference of the head.
Individuals with Dandy Walker syndrome may also elicit other not so common symptoms of the condition such as inflammation of the optic disc, clogging of the veins in the scalp, disconnection of the cranial sutures and decreased occipital squama width.
If the syndrome is accompanied by other disorders that affect the brain or the central nervous system, then the affected person may experience symptoms other than those listed above.

Types of Dandy Walker syndrome

The three types of Dandy Walker syndrome are listed below:

Dandy Walker Malformation syndrome

It is characterized by enlargement of the posterior cranial fossa that has the cerebellum and the brainstem.
The cerebellar tentorium which separates the occipital lobes from the cerebellum is raised.
The posterior midline part between the two hemispheres known as cerebellar vermis is completely missing or partially present in the most basic form. Such an abnormality is generally caused due to dysplasia affecting the brainstem nuclei
The forth ventricle present in the posterior fossa may be develop cysts. This may lead to the formation of hydrocephalus, which causes abnormal collection of cerebrospinal fluids in the brain cavities and ventricles. This may eventually result in excessive intracranial pressure within the skull as well as other associated disorders

Dandy Walker Cisterna Magna syndrome

Individuals affected by this type of Dandy Walker syndrome may elicit enlargement of the posterior fossa along with the cavities in the meninges. As a result there is increased collection of the cerebrospinal fluid in the cistern magna present in the posterior fossa

Dandy Walker Variant syndrome

It features mild bulging of the fourth ventricle and the posterior fossa.
There is underdevelopment of the cerebellar vermis leading to abnormal symptoms associated with supratentorial or hydrocephalus central nervous system problems
Individuals affected by this type may not experience inversion of the torcular-lamboid

Causes

The exact cause of Dandy Walker syndrome is not known. It is believed that the symptoms and complications associated with the disorder may be caused due to genetic and environmental factors

Abnormalities of the chromosomes and other genetic anomalies can impair cilia functionality, leading to decreased signaling ability of the motor nerves.
The presence of genetic conditions such as Myelomeningocele and/or Spina bifida can also result in Dandy Walker syndrome.
Exposure of the fetus to various environmental factors including viruses like warfarin, cytomegalovirus, rubella and toxoplasmosis increase the risk to developing Dandy Walker syndrome
Various abnormalities of the brain and the central nervous system can also trigger the symptoms of Dandy Walker syndrome

Treatment of Dandy Walker syndrome

The treatment of Dandy Walker syndrome is aimed at correcting the symptoms associated with the disorder. Some treatment methods include:

Shunting is a process that is used to reduce the intracranial pressure. It involves the insertion of a special tube in the skull so as to shunt the posterior fossa cyst, and also to prevent the excess buildup of cerebrospinal fluid and also to provide for its smooth flow
Ventriculoperitoneal anomalies are treated via shunting of the lateral ventricles which alleviates the inflammation of different parts of the brain
Vision therapy, occupational therapy, physical therapy and speech therapy may be used to overcome the various defects associated with Dandy Walker syndrome
Seizures and other symptoms may be managed via medications.