Dandy-Walker syndrome is a congenital defect associated with abnormal development of the cerebellum. The disease is recognized even before the child is born and, as a rule, is accompanied by various anomalies of other organs. A child is born and almost immediately develops hydrocele of the brain. The appearance of Dandy-Walker anomaly in children is preceded by the following factors:
- viral diseases of the mother (especially at the beginning of pregnancy);
- metabolic disorders (for example, diabetes);
- drinking alcohol, smoking, taking drugs.
Dandy-Walker syndrome - what is it?
The discovery and detailed study of Dandy-Walker malformation in the last century made it possible to identify a triad characteristic of this pathology. It includes the following signs: absence of the worm (or its partial development), neoplasms of the ventricle of the cystic type, deviation from the anatomical norm of the posterior cranial fossa (in a larger direction). The sinuses move upward, which is another sign. The cerebellum also changes its normal position.
Underdeveloped pathways for the movement of cerebrospinal fluid lead to the formation of hydrocephalus. The percentage here is high - almost 90% of patients experience discomfort due to the accumulation of cerebrospinal fluid in the ventricular system.
Diagnostics
There are two types of diagnostics - perinatal and postnatal. In most cases, Dandy Walker syndrome is suspected in utero and it is recommended to terminate the pregnancy for medical reasons, or, if the parents do not agree to this, to give birth to a seriously ill child.
However, in recent years, functional diagnostic specialists and neonatologists have begun to distinguish between complete and incomplete, open and closed forms. This classification is fundamentally important, as it largely determines the severity of Dandy Walker syndrome.
- Open and closed forms imply the presence or absence of communication between the fourth ventricle and the subarachnoid space, as well as the presence of narrowing of the lumen of the foramina of Magendie and Luxche.
- Complete and incomplete forms also differ in the degree of changes in the structure of the cerebellum and the presence or absence of communication between the cyst of the posterior cranial fossa and the ventricular system of the brain.
In any case, if this pathology is suspected, the decision remains with the parents.
During postnatal diagnosis, the doctor collects an anamnesis of the mother’s life and illnesses, finds out in as much detail as possible how the pregnancy proceeded, what complications arose, analyzes the genetics of close relatives, whether similar pathologies occurred or not. Already against the background of this information and an objective picture, the doctor can make a presumptive diagnosis. To confirm the guess, neurosonography is performed; in children under 1 year of age (while the large fontanel is not yet overgrown), ultrasound diagnostics of the brain is performed (this method allows visualization of a cyst in the posterior cranial fossa). The most informative is MRI and CT examination of the patient’s brain.
Carrying out MRI or CT diagnostics for a child is associated with some risks, since at this age such studies are carried out in medicated sleep. If there is a concomitant pathology, the procedure may cause more harm or be contraindicated.
Dandy Walker syndrome - symptoms
The syndrome is recognized around the 5th month of pregnancy thanks to ultrasound. The study shows the presence of cysts in the cranial fossa, underdevelopment of the cerebellum, and an excessive increase in the volume of the fourth ventricle. As the fetus develops, these signs become more distinct.
Later, abnormal development of the kidneys, fusion of the fingers of the upper and lower extremities (sometimes complete), and clefts formed on the palate and lip are observed. If an ultrasound was not performed during pregnancy, then immediately after the birth of the child, all of these symptoms can be easily detected.
Muscle spasms and nystagmus make themselves felt due to increased intracranial pressure (ICP). Because of this, the newborn behaves extremely restlessly. In practice, there have been cases where pronounced signs of hydrocephalus were not observed.
Manifestation of the disease
When performing a routine ultrasound, a pregnant woman reveals characteristic signs of defective fetal development. The Dandy-Walker anomaly announces itself:
- closure or complete absence of the Magendie and Luschka holes;
- inadequate parameters of the cranial fossa;
- atrophy of the cerebellar hemispheres;
- cysts;
- hydrocephalus.
The disease is considered congenital, although there are rare cases where signs appear after the age of four. In medical practice, there are isolated cases when Dandy-Walker syndrome manifests itself for the first time in an adult. The patient experiences severe muscle spasms, poor coordination, protrusion of the back of the head, and develops mental disability.
Symptoms
Signs of fetal malformation detected by ultrasound:
- Cysts and tumors in the brain,
- Reduction in the size of the cerebellum and decrease in its functions,
- Ventriculomegaly,
- External deformities - cleft palate and upper lip,
- Occlusion of foramina and absence of channels in the brain,
- Kidney abnormalities
- Inferiority of the structures of the liquor drainage system,
- Death of the cerebellar hemispheres,
- Fistulas in the brain.
Most scientists recognize Dandy-Walker syndrome as a congenital anomaly. But despite this, clinical signs of pathology may first appear in a small child, schoolchild, teenager and even an adult.
Symptoms of pathology in newborns:
- Disproportionately large head compared to the body,
- Protrusion of the back of the head
- Osteomalacia of the skull bones,
- Bulging of the fontanelle,
- Limitation or decrease in motor activity of the arms and legs,
- Involuntary movements of the limbs,
- Reduced resistance and elasticity when squeezing the skin and soft tissues,
- Arrhythmia,
- Constant crying, moodiness, restlessness of the child,
- A faint cry
- Facial deformation
- Hyperreflexia,
- Increased excitability
- Eyeball twitching,
- Strabismus,
- Convulsive contraction of the muscles of the limbs,
- Constant bending of arms and legs due to muscle tension
- Brief cessation of breathing during sleep
- Damage to the facial nerve.
The clinical picture of Dandy-Walker syndrome in adults consists of the following symptoms:
- Cerebellar symptoms - nystagmus, imprecise and wide movements, dizziness, changes in gait, dysarthria, scanned speech, tremor, incoordination of movements, inability to perform rapid alternating actions;
- Signs of high intracranial pressure and hydrocephalus - anxiety, nausea, vomiting, dull, aching headache in the morning, dizziness, pale skin, weakness, lethargy, reaction to bright light and loud sound, walking “on tiptoe” with hypertonicity of the leg muscles, lethargy, mnestic disorders, inattention, convulsive syndrome, coma;
- Impaired motor coordination - difficulty walking, muscle hypertonicity, spasms and muscle tension, frequent seizures;
- Incurable retardation in intellectual development - patients do not recognize their relatives, cannot read, distinguish letters, write, become irritable, forgetful;
- Symptoms of kidney abnormalities are periodic lower back pain, increased blood pressure, swelling on the face around the eyes, on the body and legs, difficulty urinating, burning and itching during this process, cloudy urine with bloody discharge;
- Signs of congenital heart disease are shortness of breath that occurs during minor physical exertion, increased heart rate, general weakness and pale skin, cyanosis, heart pain, fainting, swelling of the extremities;
- Syndactyly, deformation of the face and the entire skull, increased volume of the head;
- Impaired visual function – decreased visual acuity, diplopia.
The outcome of the syndrome largely depends on the depth of damage to the central nervous system, as well as on the presence of concomitant pathology accompanying this disease. Serious complications of the disease include intellectual and psychological defects, slow psychomotor development, and neurotic diseases. Failure of higher mental functions, cognitive disorders and motor awkwardness are the most common consequences of the disease.
Video: example of an adult patient with Dandy-Walker syndrome (eng)
Forms of manifestation of the disorder and complications
If we talk about the varieties of the disease, then there are two of its forms - complete and incomplete. In the complete form, the cerebellar vermis is completely absent; the incomplete form is characterized by partial underdevelopment of the cerebellar parts.
Among congenital pathologies of the development of the nervous system, many diseases belong to the class of dangerous. Dandy-Walker malformation turns out to be one of the most difficult diseases in terms of the course, treatment and subsequent prognosis. The mental development defect in this disorder is irreversible. The neurological status may also remain for life - muscle hypertonicity and improper coordination of movements will be observed.
Consequences
Often the prognosis for such an anomaly is unfavorable. The life expectancy of a child is determined by the presence of a concomitant illness. According to statistical data, the death of a baby can often occur if the syndrome develops after childbirth. Serious complications of the disease include:
- Intellectual and psychological defects that cannot be corrected throughout life;
- Slow psychomotor skills;
- Neurotic diseases, namely, increased muscle tone, impaired motor function.
Since the disease is congenital and progresses at the genetic level, it cannot be prevented. Therefore, preventive measures will be meaningless. However, while a woman is carrying a baby, she should be periodically examined using ultrasound to timely detect the development of an anomaly. If a pregnant woman is suspected of developing Dandy-Walker syndrome in her baby, an ultrasound examination is prescribed at intervals of several weeks. If a pathology is detected, the level of the child’s impairment is examined and a decision is made on whether it is advisable to continue the pregnancy in the future.
It should be noted that the risk of the formation of such an anomaly increases significantly if a woman continues to smoke and drink alcohol during pregnancy. For this reason, pregnant women are advised to maintain a healthy lifestyle, since the consequences that may arise from such an attitude are often not compatible with life.
Dandy-Walker syndrome - diagnosis
At the first stage, the doctor examines the patient and collects anamnesis to make a correct diagnosis. This procedure is performed when manifestations of the disease were noticed only after birth.
The second stage involves a neurological examination. On it, the doctor detects frequent involuntary eye movements in different directions (nystagmus) in the patient; a protruding fontanel is visible in the child. Muscle tone may be reduced, and the head has dimensions unusual for this age (it is larger).
An ultrasound procedure can detect signs of disease in a child in the womb. The method is also good in the later stages of the disease, when it becomes necessary to examine the heart for defects.
A reliable method that allows diagnosis with a high degree of accuracy is magnetic resonance imaging (MRI). Thanks to the study, the following is revealed:
- the presence of cystic neoplasms in the cranial fossa;
- abnormal development of the cerebellum;
- expansion of the fourth ventricle;
- dropsy of the brain.
Sometimes, to complete the clinical picture, consultation with a geneticist and neurosurgeon is required.
Dandy-Walker syndrome - treatment
Each form of anomaly is characterized by a certain degree of severity. Newborns with a severe form of the disorder have virtually no chance of survival. In the case where the defect turns out to be compatible with the life of the infant, its mental development is associated with great problems. Every parent, having heard such a diagnosis, should be prepared for the fact that their child will forever remain with a low level of intelligence. No amount of remedial training can help in this case. It is almost impossible to give an accurate forecast, but the likelihood of death is extremely high.
In addition, it is almost pointless to treat the anomaly and hope for a complete recovery. If the swelling of the brain gets worse, the doctor will plan surgical treatment. Reducing the pressure inside the skull is achieved by shunting the fourth cerebral ventricle.
General information
Dandy Walker syndrome in a child - photo:
The pathology affects the 4th ventricle of the brain, where excess fluid accumulates . If the cerebrospinal fluid pathways are not fully developed, this fluid cannot be sufficiently removed from this area, resulting in its pathological accumulation.
The cerebrospinal fluid compresses other areas of the brain, which leads to increased intracranial pressure. As a result of increased pressure in the brain area, a certain effect occurs on the nuclei of the cranial nerves , which leads to the appearance of characteristic signs of the disease.
The constant accumulation of cerebrospinal fluid leads to the formation of a specific cavity in which this fluid is contained. Over time, the size of this cavity can increase, which leads to an even greater increase in intracranial pressure and the development of the disease.
Brain structures that are subjected to constant compression cannot fully develop, as a result of which the functionality of the organ is lost.
The disease occurs in approximately 0.0025% of cases, more often in girls.
