Dandy Walker Syndrome

Dandy Walker syndrome is a disorder of the brain that is present from birth. Patients will elicit abnormalities in the cerebellum as well as in the cerebrospinal fluid filled areas in and surrounding the cerebellum. It is named after Walter Dandy and Arthur Walker who are regarded as the founders of neurosurgery.

Dandy Walker syndrome is marked by incomplete or nil development of the brain located between the right and left hemisphere, formation of a cyst in the internal base area of the brain, and swelling of the fourth ventricle. The occurrence of such brain anomalies has resulted in the condition being also referred to as Dandy Walker cyst syndrome. Other symptoms experienced by patients include buildup of cerebrospinal fluid, blood flow with increased pressure to the brain, and/or narrowing of the areas that hold the fluid.

Dandy Walker syndrome occurs at random, without any specific trigger. However, girls are more prone to developing it than boys. Dandy Walker syndrome is believed to be one of main causes of varied central nervous system abnormalities.

Prognosis

The prognosis of Dandy Walker Syndrome is complicated. It is observed singularly that children with this condition do not have normal mental development. The prognosis also depends on the intensity of the syndrome and related conditions. With a higher degree of multiple hereditary defects, the life span can be shortened.

Types

Dandy Walker syndrome occurs in three forms as listed below:

• Dandy Walker Variant syndrome: It is identified by the below listed brain abnormalities:
  • The cerebellar vermis may not form completely. This can then result in a variety of adverse symptoms related to central nervous system problems of hydrocephalus or supratentorial.
  • The torcular-lamboid may be inverted/reversed in people with this type of Dandy Walker syndrome.
  • The posterior fossa and fourth ventricle may experience minor swelling or bulging.
• Dandy Walker Cisterna Magna syndrome: It is identified by the below listed brain abnormalities:
  • In this type of Dandy Walker syndrome, the posterior fossa as well as the empty spaces occurring in the meninges may experience enlargement. Subsequently, the cistern magna occurring in the posterior fossa may experience excessive buildup of cerebrospinal fluid.
• Dandy Walker Malformation syndrome: It is identified by the below listed brain abnormalities:
  • The cerebellar vermis, i.e., the posterior midline section sandwiched between left and right hemispheres, is either absent or occurs in an incomplete primitive form. Such a defect typically develops due to dysplasia of the brainstem nuclei.
  • The posterior cranial fossa containing the brainstem and the cerebellum may be enlarged.
  • Development of cysts in the 4^th ventricle occurring in the posterior fossa. This can trigger the development of hydrocephalus, which in turn may cause increased accumulation of cerebrospinal fluid in the ventricles and in the empty spaces of the brain. Eventually, patients of Dandy Walker syndrome may experience elevated intracranial pressure and other related ailments.
  • Elevated positioning of the cerebellar tentorium, a part of the brain which divides the cerebellum from the occipital lobes.

Symptoms

The varied signs and symptoms of Dandy Walker syndrome may occur abruptly or slowly over a period of time. A few common symptoms are discussed below:

• Infants with Dandy Walker syndrome may suffer from bulging of the front fontanel, continued skull size enlargement, and deficient or low rate of motor skills development.
• Children and adults may suffer from a host of cerebellar system dysfunctions, including swelling at the back of the skull; ataxia, i.e., deficient or absent coordination of muscles; ticks of the limbs, face, and eyes; imbalance; increase in the overall circumference and size of the head; and anomalies in breathing patterns.
• Elevated pressure within the cranium in children with Dandy Walker syndrome can trigger diverse symptoms such as vomiting, increased irritability, and seizures, etc.
• Blockages of the veins present in scalp; lowered width of the occipital squama; inflammation or swelling of the optic disc; and disjoined sutures in the cranium may also occur. These symptoms are however rare.
• The presence of varied underlying associated anomalies may result in varied symptoms such enuresis when sleeping at night, unusual repetitive motor movements, hyperactivity, and other behavioral problems.
• The presence of other types of central nervous system and/or brain disorders along with Dandy Walker syndrome may result in numerous other symptoms in addition to those mentioned above.

Causes

Doctors are not aware about the exact cause of Dandy Walker syndrome. Environmental and genetic factors are thought to play a role in the development of the varied abnormalities and adverse symptoms associated with Dandy Walker syndrome.

• Underlying occurrence of Spina bifida, Myelomeningocele, and other genetic conditions can trigger the development of Dandy Walker syndrome.
• The functioning of cilia may get compromised due to presence of varied genetic defects including chromosomal abnormalities. This can result in reduced capacity of the motor nerves to transmit signals.
• The risk to development of Dandy Walker syndrome is increased due to fetal exposure to different environmental elements such as cytomegalovirus, warfarin, toxoplasmosis, rubella, and other pathogens.
• Underlying central nervous system and brain defects are other causes that can facilitate the onset of Dandy Walker syndrome.

Treatment

Most of the treatment options associated with Dandy Walker syndrome are focused on remedying the abnormal symptoms. A few common treatments are listed below:

• A special surgical procedure called shunting is used to place a unique tube or a shunt within the skull. This helps reduce the intracranial pressure as well as the pressure within the brain.
  • Placing cystoperitoneal shunts in the posterior fossa can treat cysts via draining of the excess amounts of cerebrospinal fluids, which then facilitates its smooth flow.
  • Placing ventriculoperitoneal shunts in the lateral ventricles can help decrease inflammation in different areas of the brain.
• Seizures and other abnormalities can be controlled via medicines and self-care measures such as avoiding bright lights during a seizure.
• A variety of therapies, including speech therapy, physical therapy, vision therapy, special education, and occupational therapy, etc. can help in overcoming the adverse effects of the Dandy Walker syndrome.
• Couples who already have a child with Dandy Walker syndrome need to go for genetic counseling before conceiving another child.

Dandy Walker syndrome life expectancy

Most patients of Dandy Walker syndrome tend to live a life that is dependent on others for care and support. The life expectancy of Dandy Walker syndrome patients is dependent on the severity of the disorder; higher is the level of severe symptoms, then higher is the risk to development of health complications, and subsequently lower is the life expectancy.