Dandy walker syndrome occurs when there are defects in some parts of the brain, particularly the cerebellum and surrounding areas. This condition causes a wide array of problems that can either be inconspicuous or obvious. People affected by this syndrome have difficulties in controlling their movements; coordination of the eyes and muscles; speaking and understanding language. They tend to have defective organs, such as the kidneys, urinary tract and heart, to name a few.
Dandy walker syndrome is present at birth and early diagnosis can significantly improve the chances of survival and normal functioning. This differs from patient to patient, though, as each case is unique and life expectancy is cut short for those who are born with several defects or those individuals suffering from health problems.
Dandy Walker syndrome (DWS) is brought about by an abnormal brain development that caused the cerebellum to become defective or abnormally formed, specifically at the posterior part of the brain. In many of DWS cases, some other parts of the cerebellum are defective as well. The abnormalities observed in the cerebellum that lead to the syndrome involve the following:
- Very small or completely absent cerebellar vermis. This is a worm-shaped tube that connects the two sides of the cerebellum.
- Abnormally large posterior fossa or the small part of the skull that houses the cerebellum and brainstem, due to the presence of cyst.
- Development of cyst in the fluid-filled cavity called fourth ventricle through which fluid coming from the brain passes as it goes to the spinal column.
The exact cause of the syndrome is still unknown. However, extensive research has revealed sufficient information that has helped in the understanding of the nature of the condition.
- Genetic mutations
Mutations in some of the genes of the individuals afflicted with DWS had been observed.
- Chromosomal abnormalities
Studies showed that those with DWS have extra copies of some chromosomes, particularly chromosomes 18, 13, 21 or 9. Moreover, the condition has been found to also occur in people born with one extra copy of all chromosomes in every cell.
The cerebellum or the area of the brain that is involved in movement control, coordination and cognition is the defective part in the case of DWS. Persons affected by DWS will have problems in relation to these neurological functions but at varying degrees. These problems may go unnoticed for some people or be very obvious in others.
Among the problems caused by DWS to include:
Delayed motor development
Babies affected by this syndrome learn to crawl, walk or perform coordinated movements much later than normal babies of their age.
Problems with coordination and movement
There is lack of coordination between muscles resulting in muscle stiffness, unsteadiness, and jerky eye movements. Those afflicted by the condition also seem to be irritable and deal with seizures frequently. Vision and hearing are affected as well.
Sufferers experience some measure of intellectual disability which could be mild or severe. These cognitive deficits make it difficult to learn how to speak and understand language.
External and internal malformations
A DWS child has a progressively enlarged skull, causing bigger head circumference. There might likewise be some bulge at the back of the skull. The vast majority of DWS patients have some form of heart defect, abnormal facial appearance, extra fingers or toes, and malformed kidneys or urogenital tract.
Around 80% of DWS cases are detected during the first 12 months of life. Some develop the symptoms later during childhood.
Statistics show that DWS rarely occurs, affecting approximately 1 child out of 25,000 to 30,000 births. It mostly occurs as a result of random events during the early stages of pregnancy. There are no known risk factors for the syndrome but experts believe that certain things can affect the optimum brain development during pregnancy, hence, resulting in DWS. These include:
- Rubella infections
- Exposure to teratogens
Some children inherit the defective gene that causes some of the features of Dander walker syndrome. However, relevant environmental factors should also be present for this to happen.
The treatment for the condition aims to provide some measure of relief by addressing the problems associated with it as well as prevent them from aggravating. For instance, there is a swelling on the back part of the skull due to fluid buildup thus causing intracranial pressure. This is dealt with by draining the fluid through inserting a tube into the skull. The intracranial pressure felt will then be reduced. Other accompanying problems are treated as well, including multiple malformations and organ defects. Meanwhile, specialized education can provide the needed support for intellectual or learning disabilities; speech therapy can help the patient speak and understand speech. A patient affected by Dandy Walker syndrome will also benefit from physiotherapy and occupational therapy.
The life expectancy of Dandy Walker Syndrome depends on the related conditions caused by the syndrome. So, if a person has a higher degree of deformities and irregularities, the life span could be shorter. The quality of life of a person with a DWS is dependent on medical care, attention and love from people around him or her.