Dandy Walker Syndrome

Dandy-Walker syndrome is a rare and rather serious malformation of the cerebellum and the fourth ventricle. It is considered a congenital anomaly in children and is common with a frequency of 1: 25,000. This defect is characterized by hypoplasia or hypoplasia of the cerebellar worm, cystic enlargement of the fourth ventricle and expansion of the posterior cranial fossa. Syndrome may be accompanied by multiple anomalies of other organs, but the main three can be considered as listed above. Approximately 70-90% of patients have hydrocephalus, which often develops immediately after birth. Fortunately, the pathology can be seen even at the stage of pregnancy.

[1], [2], [3], [4]

Causes of the dandy Walker Syndrome

Unfortunately, even modern medicine can not yet confidently answer the question of what causes lead to the development of the Dandy-Walker syndrome. Of course, there are some risk factors that in one way or another can lead to intrauterine malformation. For the formation of this anomaly, an important role is played by:

1. Viral diseases that the mother tolerates during pregnancy (especially should beware of infections in the first three months).
2. Cytomegalovirus infection.
3. Rubella.
4. Diabetes mellitus or other diseases associated with a metabolic disorder in a future mother.

Quite often, various pathologies of the fetus during intrauterine development appear in women who suffer from alcoholism or drug addiction. In most cases it is these mothers who are born with children with Dandy-Walker syndrome. If during the ultrasound the doctor sees that the fetus develops abnormally, he recommends aborting the pregnancy. In very rare cases, the Dandy-Walker syndrome develops for hereditary reasons.

[5], [6], [7], [8]

Pathogenesis

The Dandy Walker Syndrome was first described by Dandy and Blackfen in 1914. After the initial description, additional studies were conducted that described the various morphological features of this defect.

The studies of D'Agostino in 1963 and Hart in 1972 determined the characteristic triad of the Dandy Walker syndrome, namely:

1. Complete or partial worm agenesis
2. Cystic dilatation of the fourth ventricle
3. An increase in the posterior cranial fossa with an upward movement of the lateral paranasal sinuses and the cerebellum.

This triad, as a rule, is combined with supratentorial hydrocephalus, which are complications, and not part of the complex of malformation.

Classically, the cystic defects of the posterior cranial fossa are divided into the Dandy Walker syndrome, the Dandy Walker variant, the mega cistern magna, the cyst of the arachnoid casing of the posterior cranial fossa - these are the defects that make up the Dandy Walker complex.

The Dandy-Walker variant combines worm hypoplasia and cystic enlargement of the fourth ventricle, without an increase in the posterior cranial fossa.

This syndrome is an innate pathology, which manifests itself in the fact that the cerebrospinal pathways and the cerebellum do not fully develop. Most of the anomaly concerns the holes that connect the two ventricles (third and fourth) with a large cistern of the brain, and those that connect these same ventricles with the subarachnoid space of the brain membranes. Due to the disturbance of the liquor flow, the formation of a cystic cystic formation in the posterior cranial fossa and obstructive hydrocephalus as a result of secondary cystic dilatation of the fourth ventricle occurs (70-90% of cases).

Associated with the anomaly of the Dandy Walker developmental defects of the central nervous system (70% of cases):

• Dysgenesis of the corpus callosum (20-25%).
• Lipoma of the corpus callosum.
• Goloprozenzepalya (25%).
• Porencephaly.
• Dysplasia of the cingulate gyrus (25%).
• Shizentsefaliya.
• Polymicropathy / heterotopy of gray matter (5-10%).
• Cerebellar heterotopy.
• Occipital encephalocele (7%).
• Microcephaly.
• The dermoid cyst.
• Malformations of the lobules of the cerebellum (25%).
• Malformation of the lower olivar nucleus.
• Hamartoma in the gray hillock.
• Syringomyelia.
• The Klippel-Feil deformation.
• Spina bifida.

Other rarely occurring associated malformations of the central nervous system (20-33% of cases):

• Orofacial deformities and palate (6%).
• Polydactyly and syndactyly.
• Anomalies of heart development.
• Anomalies of the urinary tract (polycystic kidney).
• Cataract of the retina, dysgenesis of the choroid, coloboma.
• Hemangioma on the face.
• Hypertelorism.
• Meckel-Gruber syndrome.
• Neurocausal melanosis.

[9], [10]

Symptoms of the dandy Walker Syndrome

This anomaly in the development of the child can be seen with the help of ultrasound in the first months of pregnancy. In particular, all the symptoms of this disease are visible for 20 weeks. The main evidence of the development of pathology is a variety of signs of brain damage: clearly visible cysts in the cranial fossa, poorly developed cerebellum, the fourth ventricle is too much expanded. In this case, ultrasound signs become more distinct as the fetus develops.

Over time, crevices appear on the hard palate and lip, abnormal kidney development, and also syndactyly. If, for any reason, ultrasound during pregnancy was not performed, the symptoms of the disease become clearly visible immediately after the birth of the child. Because of the high pressure inside the skull, these children are very restless. They develop hydrocephalus with muscle spasms, nystagmus. In some cases, signs of hydrocephalus may not be.

[11], [12]

First signs

1. Atresia of the holes of Magendi and Lushka (infection or congenital absence).
2. The posterior part of the cranial fossa increases in size.
3. Atrophy of cerebellar hemispheres.
4. There are cystic formations, including fistulas.
5. Hydrocephalus of different degree.

All these early signs are clearly visible during the ultrasound of the fetus. That is why it is so important to pass all the tests and studies on time to pregnant women on time.

[13], [14], [15]

Dandy-Walker Syndrome in children

A priori Dandy-Walker syndrome is considered just a child's disease. Fortunately, it is quite rare (just one case for 25,000 newborn babies). His symptoms can be seen even in the womb, but if, for some reason, this was not done, then children with this disease develop severe and severe complications with age.

Over time, there are noticeable cerebellar symptoms. In older children, coordination of movements begins to be disturbed, so it is difficult for them to walk and walk (sometimes even impossible). The main symptom is a strong mental retardation, which can not be cured. There are also accompanying problems: diseases of the kidneys, heart, abnormal development of the fingers, face, hands, poor vision.

[16]

Dandy Walker Syndrome in Adults

Dandy Walker Syndrome is an anatomical clinical variant of vicious hydrocephalus. This disease is characterized by the atresia of the holes in the brain, as well as the expansion of the ventricles (third and fourth).

Despite the fact that this pathology is considered congenital, in very rare cases, its first signs begin to manifest in early childhood (four years of age) or even later. For a long time, there are no symptoms of this congenital malformation. Decompensation sometimes occurs only in children of school age or adolescents. The cases when the first symptoms of the Dandy-Walker syndrome are manifested in adults are exceptional.

Among the main symptoms of the disease in adults can be identified:

1. The size of the head gradually increases.
2. The bones of the nape begin to protrude: they seem to bulge.
3. Coordination of movements is strongly violated, there are indistinct and sweeping movements.
4. Nystagmus develops, which manifests itself in the vibrational movements of the eyes from side to side.
5. Frequent seizures with convulsions.
6. Muscle tone is greatly increased (sometimes to spasticity). Muscles are in constant tension.
7. The development of mental inferiority, which manifests itself in the fact that a person does not recognize relatives, hardly reads and distinguishes letters, can not write.

[17], [18], [19], [20],

Dandy-Walker syndrome in pregnancy

As a rule, by means of ultrasonic research the Dandy-Walker syndrome can be seen already on the 18-20th week of pregnancy. During this period, full or partial agenesis of the cerebellar worm can be seen. In very rare cases prenatal diagnosis of this disease is possible at an earlier date.

[21], [22]

Forms

There are two forms of Dandy-Walker syndrome, which differ in the degree of anatomical disorder:

1. The full form - the underdevelopment of the cerebellum worm is complete.
2. Incomplete form - only part of the cerebellum develops incorrectly.

[23], [24], [25], [26], [27]

Complications and consequences

Certainly, many congenital pathologies are very serious, but Dandy-Walker syndrome is considered one of the most severe anomalies in children. This disease leads to rather complex consequences:

1. Mental defect remains for life.
2. Often preserved and neurological defect - muscle tone is increased, coordination of movements is incorrect.
3. A lethal outcome can be expected in most cases.

[28], [29], [30]

Diagnostics of the dandy Walker Syndrome

First of all, the doctor conducts diagnosis of complaints and anamnesis of the disease (if Dandy-Walker syndrome manifests itself after birth). This stage includes answers to some questions:

1. Has this happened in the family before?
2. At what age did the first signs of the disease begin to appear?
3. When did the coordination of movements begin to break, the head increase, the muscle tone change?

Further the expert should spend a neurologic survey. During this stage, one can see the development of nystagmus (involuntary vibrational movements of the eyes in different directions), bulging of the fontanelle, a decrease in muscle tone, an increase in the size of the head.

Conducting an ultrasound study during pregnancy helps to see the first signs of fetal syndrome. In addition, the same method can be used and in the late stages of the disease to check the heart for the presence of vices.

Thanks to the MRI (magnetic resonance imaging) of the brain, you can see the extent of the increase in the size of the head, the appearance of a cyst in the posterior cranial fossa, expansion of the ventricle, abnormal development of the cerebellum, hydrocephalus.

In some cases, you need to consult a neurosurgeon physician or a medical geneticist.

Instrumental diagnostics

The most common methods of instrumental diagnosis for detecting the first symptoms of Dandy-Walker syndrome are ultrasound (fetal ultrasound) and MRI (magnetic resonance imaging). As a rule, abnormal development of the child is noticeable at the first ultrasound, which is carried out on the 18-20th week of pregnancy. If a specialist can not make an accurate diagnosis or needs confirmation, he can prescribe an MRI. The diagnosis, delivered with MRI, is accurate by 99%.

[31], [32], [33], [34], [35]

Differential diagnosis

Differential diagnosis of Dandy-Walker syndrome is usually carried out with the expansion of a large brain cistern that develops in the inflammatory or toxic hypoplasia of the cerebellum, as well as with the retrocerebral cyst. But here it should be borne in mind that with the Dandy-Walker syndrome the cerebellar worm has a pathognomonic defect that is not observed in another hypoplasia. To perform differential diagnosis of this pathology with arachnoid cysts, it is necessary to do an MRI.

Treatment of the dandy Walker Syndrome

The Dandy-Walker syndrome has a different severity. As a rule, children who are born with a severe form of this anomaly die in the first month of life. If the vice is compatible with life, then the development of the child in the psychic plan is considered very problematic. Parents should be prepared for the fact that the child will have a very low intellect, which can not be changed with the help of correctional training. The prognosis of the development of the baby with the Dandy-Walker syndrome is extremely unfavorable.

To treat such an anomaly practically does not make sense. But if hydrocephalus starts to build up, then surgical intervention is required. Intracranial pressure can be reduced by shunting IV of the ventricle of the brain.

Treatment for Dandy-Walker syndrome can only be symptomatic. Mental retardation of the child is not subject to correction, the motor functions of the body are severely disturbed, so usually such children can not sit or stand alone.

In the treatment it is very important to remember about concomitant diseases of the heart, kidneys, maxillofacial pathology. They often require qualified medical intervention.

If the doctor reveals this anomaly in the fetus, then the parents must make a rather difficult choice: interrupt the pregnancy or give birth to a child who will suffer from an incurable pathology all his life.

Operative treatment

The only way to promptly treat Dandy-Walker syndrome is bypass, which helps reduce the severity of hydrocephalus symptoms and improve the outflow of liquor.

Prevention

Due to the fact that the Dandy-Walker syndrome is a disease with a hereditary character, it is considered senseless to conduct its prevention. It is recommended during pregnancy to regularly visit an obstetrician-gynecologist (once a month during the first trimester, once every two to three weeks during the second trimester and once every seven to ten days during the third trimester). Try to become on time in the account in a female consultation (before 12 weeks of pregnancy).

[36], [37], [38]

Forecast

The prognosis for Dandy-Walker syndrome is catastrophically unfavorable. In 50% of cases the child dies in the first year of life. Those children who survived should be constantly under the watchful eye of doctors. They have an extremely low level of intelligence, which is not subject to correction. The syndrome occurs with a pronounced functional neurologic status.

[39]

Disability

Congenital malformations of the central nervous system, in particular the Dandy Walker syndrome, lead to severe disability from the first minutes of life.

[40], [41], [42], [43], [44]