Dandy Walker Malformation: Causes, Symptoms, and Treatment
Jul 16, 2021
Congenital diseases occur during the intrauterine development of the baby. In this article we will talk about one of them: Dandy Walker malformation, which affects the cerebellum and nearby regions and produces severe symptoms such as hydrocephalus.
We will explain what they are the causes of this syndrome and what signs and symptoms can help identify it. Early detection of this malformation can be essential to ensure the survival of the baby.
What is Dandy Walker Malformation?
Dandy Walker syndrome is a brain disorder that occurs during embryonic development. Specifically, malformations in the cerebellum at the base of the skull and in the fourth ventricle.
The cerebellum is located in the lower part of the brain. It is involved in the control of movement, cognition, attention, and learning. Damage to the cerebellum often makes movement, balance, and motor learning difficult.
The cerebral ventricles are cavities in the brain through which the cerebrospinal fluid, which cushions blows to the head and transports nutrients to the brain, among other functions similar to those of blood plasma. The fourth ventricle connects the brain with the central canal of the spinal cord.
The Dandy Walker malformation occurs in 1 out of every 30 thousand births approximately, and is the cause of between 4 and 12% of cases of infantile hydrocephalus. It is more common in girls than in boys.
Approximately 70% of babies with this syndrome die. However, the prognosis varies according to the intensity of the alterations. While some affected children develop normally in the cognitive area, others may have very severe impairments even after treatment.
- Related article: "Human cerebellum: its parts and functions"
Symptoms and signs
The three main manifestations of posterior fossa alterations are underdevelopment of the cerebellar vermis, which connects the two hemispheres of this structure, the cystic dilation of the fourth ventricle and the increase in the size of the posterior cerebral fossa, located at the base of the skull.
The Dandy Walker malformation frequently causes hydrocephalus, a disorder in which cerebrospinal fluid builds up in the brain, increasing cranial pressure, inflaming the head, and damaging the brain.
The symptoms of this disease vary depending on the severity of the case and age. In addition to hydrocephalus, girls and boys diagnosed with Dandy Walker usually present the following associated signs and symptoms:
- Muscular atrophy
- Alteration of muscle tone
- Incoordination and lack of balance (ataxia)
- Delayed motor development
- Cognitive deficits
- Increased intracranial pressure
- Nystagmus (uncontrollable eye movements)
- Convulsive crisis
- Respiratory failure
Causes of this syndrome
Dandy Walker malformation occurs due to alterations in the development of the cerebellum and surrounding areas during early gestation. Specifically, this syndrome has been associated with the deletion, absence, and duplication of some chromosomes.
Genetic components related to these alterations have been found, possibly linked to the X chromosome or consisting of autosomal recessive inheritance. The risk of recurrence in children of women who have already had babies with Dandy Walker is between 1 and 5%.
These genetic factors are multiple and they can interact with each other, as well as give rise to different alterations of the posterior cerebral fossa.
Environmental factors may also be relevant in the development of this disorder, although they seem to be less important than biological factors.
Normally, the malformations of the posterior cerebral fossa are classified within the Dandy Walker syndrome, although there may be various alterations depending on the affected areas.
A similar disorder is what we know as "variant of Dandy-Walker syndrome"; This category includes conditions of the cerebellum and fourth ventricle region that are not strictly classifiable as a Dandy-Walker malformation.
In these cases the signs and symptoms are less severe: generally the posterior fossa and the fourth ventricle are less enlarged and the cystic part is also smaller. Hydrocephalus is less common in the Dandy-Walker syndrome variant.
Other nearby diseases are ciliopathies, which affect intracellular organelles called cilia. Ciliopathies are caused by genetic defects and cause multiple different alterations in body development, including those that are typical of the Dandy-Walker.
Intervention and treatment
Hydrocephalus is treated by draining the affected areas of the brain in an assisted way: a tube is surgically inserted to redirect cerebrospinal fluid to regions where it can be reabsorbed.
Another method that has been used recently in the treatment of Dandy Walker syndrome is the puncture of the third ventricle. This is done with the goal of reducing the size of the ventricular cyst and thus reducing symptoms.
Motor therapy and language rehabilitation they are essential to help children with this disease. The support of families is also key to ensure the well-being and proper development of the little ones.