Dystopia of the cerebellar tonsils according to the Arnold Chiari type. Diagnosis and treatment of Arnold-Chiari malformation

At the end of the nineteenth century, the Austrian pathologist Hans Chiari first described an anomaly, which in the next century received the name "Arnold-Chiari syndrome". Malformation is a congenital pathology.

What is Arnold-Chiari syndrome?

With this anomaly, the entire structure of the posterior fossa of the skull descends below the foramen magnum.

The BZ is the border zone between the spinal cord and the brain. In the absence of pathology, cerebrospinal fluid or cerebrospinal fluid moves freely in the subarachnoid space. With the syndrome Arnold-Chiari the cerebellar tonsils clog the hole, thereby disrupting the outflow of cerebrospinal fluid, which contributes to the formation of hydrocephalus.

Types and degrees of disease

Arnold-Chiari syndrome has three types – I,II and III,IV. All of them are associated with a low location of the cerebellar tonsils.

At general pathology, types of MK have certain differences:

• Type I syndrome represents a prolapse of the tonsils and a displacement of the small brain below the BZ. With this type of anomaly, the posterior cranial fossa is small.

When conducting diagnostics, three variants of the syndrome can be distinguished - anterior, intermediate and posterior:

1. At front version there is a posterior displacement of C2, hanging over the odontoid process, basilar impression and platybasia;
2. If there is an intermediate option compression occurs by the displaced tonsils of the ventral cerebellum medulla oblongata and upper segments of the spinal cord;
3. Rear option leads to compression of the upper cervical sections of the spinal and dorsal parts of the medulla oblongata.

First type of Chiari malformation Neurologists consider it the most common disease. More often than others, it affects women who gave birth late and entered the premenopausal period.

• Type II syndrome has a congenital form. Pathology progression occurs during intrauterine development. The anomaly can be detected during examination of the fetus. , IV ventricle, the lower part of the vermis is wedged 2 mm below the entrance to the large posterior foramen.
• Type III pathology is characterized descent of the small and medulla oblongata to the meningocele of the cervical-occipital region.
• IV type of pathology represents underdevelopment of the cerebellum without descent of the tonsils into the cerebral cortex.

At the beginning of the twenty-first century it was allocated zero type of anomaly. It is determined by the presence of hydromyelia without descended tonsils of the small brain.

Attention! Type IV Arnold-Chiari malformation began to be referred to as Dandy-Walker pathology.

Elena Potemkina, after a series of studies, proposed to classify the syndrome according to the degree of descent of the cerebellar tonsils into the foramen magnum:

• 0 degree– tonsils are located on upper level ZO;
• 1st degree– the tonsils have moved to the upper edge of the arch of the atlas or C1;
• 2nd degree– at the level of the upper edge of C2;
• 3rd degree– at the level of the top of C3 and below, in the caudal direction.

Second and third types syndrome manifests itself along with other diseases of the central nervous system. Third and fourth incompatible with life.

Symptoms

Signs of Arnold-Chiari malformation can be either independent or common.

These include following symptoms, which are worth paying attention to:

• When turning the head and at rest an unusual increasing sound is heard in the ears in the form of noise, hum, whistle;
• At physical activity appears due to tension headache;
• Twitching eyeballs or nystagmus;
• Pain in the back of the head in the morning. Increased intracranial pressure, numbness;
• Due to dysfunction of the cerebellum dizziness and loss of orientation may occur;
• It is observed in movements clumsiness;
• In severe forms of the disease tremor of the limbs appears. read here.
• Problems with vision appear in the form of “veils before the eyes”, doubling of objects, blindness. When turning the head, the phenomena intensify. This is due to pressure on the medulla oblongata;
• Muscles of the limbs, faces and torsos become significantly weaker;
• Problems with urination observed in advanced and severe forms of the disease;
• The sensitivity threshold becomes less in one part of the body or face, limb;
• At sharp turns heads the patient may lose consciousness;
• Work disruption respiratory system – heavy breathing or its complete stop;
• Severe complications– paralysis of the limbs, hydrocephalus, cyst formation in the spine, deformation of the bones of the foot.

Distinctive feature syndrome type I is a persistent headache. At type II, which appears immediately after birth or during early childhood You may experience problems with swallowing and a weak cry.

All of the above symptoms become worse with movement.

Attention! At untimely application to a doctor and without treatment, a cerebral or spinal cord.

Ask your doctor about your situation

Reasons for the anomaly

Scientists have not yet fully studied the reasons for the appearance Arnold-Chiari syndrome. Chiari malformation, as the anomaly is also called, can develop due to several factors.

Congenital:

• Abnormal development of the fetal skull bones– too small posterior fossa the skull is correct developing baby leads to a discrepancy between the growth of the bones of the skull and brain. The cranial bones simply cannot keep up with the brain.
• The fetus experiences a hyperincrease in the BZO.

Purchased:

• During childbirth a traumatic brain injury occurred;
• Due to poor circulation livcor in the ventricles of the brain damages the spinal cord. It thickens.

Arnold-Chiara syndrome can occur simultaneously or after other defects, for example - dropsy of the spinal cord.

Not so long ago, experts believed that this disease was congenital, but the percentage of patients with congenital anomaly much less than the percentage acquired syndrome.

Risk factors

The risk of malformation in the fetus can be increased by factors such as:

• Uncontrolled taking medication during pregnancy;
• Availability bad habits in a pregnant woman;
• Transferred baby's mother infectious diseases. Such as rubella and others;
• Problem With good nutrition in a pregnant woman.

Most experts are of the opinion that Arnold-Chiari syndrome appears in the background genetic mutations in a child. Connections with chromosomal abnormality on at the moment not found.

Arnold-Chiari syndrome in the fetus

At ultrasound examination The doctor can detect the presence of pathology in the back of the brain. After the first trimester of pregnancy Ultrasound The contours of the baby's brain hemispheres with the nascent small brain should be visible. Unclear brain size and shape may indicate the syndrome.

Using ultrasound, specialists can identify malformation of the first and second types. In addition to this research method, echography is used. It can be used to detect lateral pointed ventricles. Correct instrumental diagnosis of the fetus helps to diagnose accurate diagnosis.

Examination and diagnosis

It happens that Chiari pathology does not manifest itself, but is detected only during examination by a doctor. At general examination with the use of EEG, REG and ECHO-EG, increased intracranial pressure. X-ray will show whether or not there are anomalies in the bones of the skull. But final diagnosis with such a check it is impossible to make a diagnosis.

If you are sure that there is a pathology, the specialist will send the patient to magnetic resonance imaging spinal and brain. During the study, the patient is prohibited from moving. Infants and children are immersed in medicated sleep , which will help to successfully conduct the examination. You may need to inject a contrast agent to obtain a clear image.

To exclude the presence of syringomyelia, it is prescribed tomography the entire spinal column.

Complications

In the absence or inappropriate treatment Arnold-Chiari syndrome paralysis may occur cranial nerves. A cyst forms on spinal column. Pathology contributes to the appearance of hydrocephalus. This will cause fluid to accumulate in the brain. For withdrawal cerebrospinal fluid doctors will resort to shunting and drainage.

Late diagnosis and treatment for Arnold-Chiari syndrome will lead to severe consequences with fatal outcome.

Treatment

If an abnormality is detected, treatment must be started immediately. Disease first two types amenable to therapy.

Conservative method

To prescribe a course of treatment, the doctor must study all the patient’s examination indicators. If the main symptom of the disease is headache, then a conservative treatment.

Nonsteroidal anti-inflammatory drugs and muscle relaxants will be prescribed:

After elimination pain syndrome are appointed diuretics. Hoarseness can be eliminated through sessions with a speech therapist. Except drug treatment, exercise is beneficial.

The course of therapy lasts several months, after which it is necessary to undergo full examination . In the absence positive results surgical treatment is prescribed.

Surgical intervention

If conservative therapy didn't bring it positive results or the patient has developed severe symptoms, then he is prescribed laminectomy, decompressive craniectomy of the PCF. As well as plastic surgery of the dura mater of the brain. This operation allows you to increase the volume cranial fossa and expand the foramen magnum. All this will lead to the cessation of compression and improvement of outflow cerebrospinal fluid.

If available hydrocephalus, then the ventricle is abducted using a special valve.

During the operation it is used electrophyological control, with which you can decide to open completely hard shell brain or not.

The rehabilitation course after surgery takes seven days.

Important! Patients with Arnold-Chiari syndrome, despite the treatment, should periodically visit a doctor.

Chiari malformation has not been fully studied and there is no way to completely prevent the development of this disease. But future parents, and especially mothers, can reduce the risk of pathology to the maximum. To do this it is necessary to conduct correct image life, study all the above risk factors and eliminate them if possible.

The health of your child depends on you.

Despite the fact that the human body is one of the most complex and resilient mechanisms, it is also incredibly vulnerable. The first disturbances in the structure and functioning of the body can occur during embryogenesis. It is the period of intrauterine development of the fetus that is very important, since at this stage all the organs and systems of the future person are laid and formed.

IN recent years more and more often they began to record the birth of children with one or another perinatal pathology, abnormalities of fetal development. Some of them are practically safe and do not pose any threat to the life and health of the child, while others, on the contrary, are very dangerous and can threaten disability or even death. One of the most multiform malformations of intrauterine development are anomalies of the nervous system. Today we will look at Arnold Chiari syndrome.

Arnold Chiari malformation is a pathological dislocation of brain structures, such as the cerebellum and tonsils, their wedging into the foramen magnum; they are located significantly lower than necessary for full functioning, as a result of which their functions are disrupted and characteristic symptoms appear.

This pathology may have varying degrees severity, therefore it is divided into 4 types.

Briefly about pathomorphology

Normally, all brain structures are located in the cranium and do not extend beyond it, ending at the level of the foramen magnum. Arnold Chiari syndrome allows the tonsils and cerebellum to descend into the foramen magnum to the level of the 1st and sometimes even 2nd cervical vertebrae. This position of these structures leads to their compression and narrowing of the lumens as blood vessels, lymphatic vessels and disruption of liquor dynamics, which is why signs of the disease appear.

Liquor or cerebrospinal fluid is a biologically active medium of the body, main function which is washing the structures of the brain and spinal cord, feeding them and sorption of waste products.

Development theory

For many years, it was believed that Arnold Chiari syndrome was exclusively congenital pathology, and the developmental defect is intrauterine in nature. On modern stage In the development of medicine, the second theory of the development of pathology is quite logical, based on which the disease is acquired against the background of the same intrauterine developmental defects. In this case, it is believed that Arnold Chiari malformation occurs due to the fact that the brain grows and develops faster bone structures and, simply put, it doesn't have enough space in the skull.

Etiology

The reasons for the development of Arnold Chiari malformation are divided depending on the theory of the development of the disease:

1. Congenital:

• past infectious diseases during pregnancy (childhood infections, TORCH);
• taking teratogenic drugs;
• alcoholism, smoking, drugs;
• harmful working conditions (toxic chemicals, ionizing radiation, etc.);

1. Purchased:

• large fruit;
• prolonged labor;
• application of obstetric forceps;
• birth trauma;
• traumatic brain injuries throughout life.

It is not known for certain why Arnold Chiari malformation develops; most likely, it is the complex influence of several of the above factors.

Classification

According to the latest standards of treatment, each nosology has its own separate column in ICD 10. According to ICD 10, Arnold Chiari syndrome has code Q07.0.

According to severity pathological process There are 4 types of disease:

1. Arnold Chiari grade 1 – characterized by minimal morphological changes, the tonsils descend just below the foramen magnum. Arnold Chiari syndrome 1 is the most promising type, since the patient has virtually no clinical signs and a favorable prognosis for life.
2. Anomaly 2 degrees – structural changes more pronounced. The cerebellum is involved in the process; it is located in the foramen magnum. Already during screening ultrasounds of the fetus, some structural defects of the spinal cord and spine can be noticed. The prognosis for life in most cases is favorable, but there are clinical signs disease, the patient requires dynamic monitoring.
3. Chiari malformation grade 3 - the cerebellum and tonsils are completely located in the foramen magnum, clinical symptoms are pronounced, the prognosis is unfavorable.
4. Stage 4 syndrome is a severe manifestation of the disease. The position of the cerebellum may not be changed, it is not developed, this malformation of intrauterine development is combined with other pathologies. The disease is most often detected in the fetus in utero. The prognosis for life is unfavorable.

In approximately 25% of cases when Arnold Chiari malformation is diagnosed, 1 patient lives with virtually no feeling of his pathology. For other degrees of severity, life expectancy ranges from several months to 10 years, this is largely due to the position of the tonsils, as well as the presence of other significant disorders in the brain and other systems.

Clinical manifestations

Arnold Chiari malformation grade 1 manifests itself in the form of regularly occurring symptoms, such as frequent severe headaches, dizziness, noise in the head and ears. Colored or black and white flies before your eyes. Another characteristic symptom is pain and discomfort in the cervical spine; often such patients have low blood pressure, this is due to the impact on vascular centers. Over time, disturbances in tactile and thermal sensitivity, paralysis and paresis of the limbs may occur, especially acute this symptom manifests itself during the period rapid growth child. Sometimes breathing problems arise; the child requires dynamic monitoring by a neurologist. One of the most striking symptoms is speech impairment. With properly selected treatment and regular sessions with a speech therapist, this manifestation can be slightly corrected.

In the second type of Chiari malformation, symptoms appear after the birth of the child in the form of breathing problems, swallowing, the child is passive, the cry is weak. Such children are often placed in a department intensive care and resuscitation, as other symptoms of impaired vital functions may occur. As a rule, in the first days it is carried out surgical treatment, the goal is to save the child’s life, the prognosis for socialization is unfavorable.

In diseases of 3 and 4 degrees of severity, patients experience tremors of the limbs, loss of consciousness, lack of cry in the first minute of life, significant impairment of all types of sensitivity, ataxia of varying severity, blindness, less often deafness, impairment pelvic functions, spontaneous urination, coordination problems.

The prognosis for life expectancy depends on the timing at which the disease was detected, the timeliness of treatment and the dedication of the parents.

Diagnostics

The main diagnostic method for this pathology during fetal development is a screening ultrasound examination to identify developmental defects, but it does not provide a 100% guarantee in this case.

Basic diagnostic procedures carried out after the birth of the child. In the first year of life, this may be an ultrasound of the brain, until the large fontanelle closes. In the future, patients suspected of having such a pathology with diagnostic purpose X-rays of the skull are performed and cervical spine spine.

Based on the results of these studies, MRI diagnostics are performed, which maximum probability allows you to establish not only the final diagnosis, but also the degree of violations and, in some cases, select adequate treatment.

Treatment

Unfortunately, Chiari malformation gives positive results treatment only for grades 1 and 2; for grades 3 and 4, treatment is more palliative in nature.

With Chiari syndrome grade 1, the patient is under constant dynamic observation a pediatrician and neurologist, practically does not require drug treatment, with the exception of analgesics that relieve headaches. Such children are prescribed physiotherapeutic treatment, but this should be done by a neurologist based on the patient’s condition. For such children, it is very important to properly organize work and rest time, choose a developmental complex therapeutic exercises. It is also possible to visit the pool and massage room to develop muscles. If there is the slightest change in their condition, they undergo a diagnostic examination.

If you have an Arnold Chiari malformation, you should be very careful about massage; under no circumstances should you massage the collar area!

For type 2, diuretics, muscle relaxants, vitamins and microelements are prescribed. As a rule, this is sufficient for maintenance therapy.

In grades 3 and 4, patients undergo surgical treatment; it is aimed at combating hydrocephalus and normalizing cerebrospinal fluid dynamics. IN modern medicine The following surgical options are used:

1. Laminectomy.
2. Decompression of the posterior cranial fossa.
3. Shunting.

Surgical treatment gives positive dynamics and allows you to stabilize the patient, but does not completely cure the disease.

Complications

Complications are associated with the compressive effect of wedging brain structures into the foramen magnum. This can lead to compression of the spinal cord, paralysis and paresis of the cranial nerves, bone defects and disturbances in the blood supply to certain parts of the spine and brain.

Forecast

Unfortunately, the forecast for this disease unfavorable. Only patients of type 1 are socially adapted.

Prevention

There is no specific prevention for this malformation. Expectant mother should be sufficiently informed about the existence of intrauterine developmental defects, stages and timing of fetal development, take care of one’s health, eat well, undergo all medical procedures in a timely manner necessary examinations, follow the recommendations of medical personnel.

Arnold-Chiari is a congenital or anomaly that occurs during the formation of a child inside the womb. The anomaly occurs due to compression of the brain, which causes deformation of the cranial regions. The consequences are: the cerebellum and brain stem strongly shift and fall into occipital part, performance is impaired.

The main causes of the anomaly

All procedures should be carried out strictly according to the doctor’s recommendation. A true specialist will not make an accurate diagnosis without conducting a proper examination.

Effective treatment of the syndrome

Currently, two types of treatment are used: surgical, when it comes to, and conservative.

Conservative treatment is used when the disease does not cause the patient severe discomfort and does not affect its development. The doctor recommends doing physical exercises and exercises for muscle coordination more often. Some medications are also prescribed: painkillers, muscle relaxants, anti-inflammatory drugs. Additionally, a complex is prescribed, especially group B, since they are responsible for biochemical processes and normalize the functioning of the central nervous system.

Of course, such prescriptions will not help to completely get rid of the disease, but they will allow you to do without surgery for as long as possible.

If the malformation of the disease is progressive, then emergency treatment will be needed. surgery. Either surgery or bypass surgery is performed. The operation solves two main reasons:

1. Correct defects that contribute to compression of the skull and brain.
2. Leads to normal condition movement of cerebrospinal fluid.

This operation is quite common and lasts no more than two hours. The patient recovers completely within a couple of weeks. Thanks to the operation, intracranial pressure is normalized, and the space in the spinal cord and brain increases, the disease recedes.

Preventive measures

You should always take care of your health, and if this is a period when a woman is pregnant under her heart, then the responsibility doubles. There are some preventative measures to prevent the disease:

• include more fruits and vegetables in your diet
• drink fresh juices, eat dairy products and meats rich in protein
• take prenatal vitamins
• give up bad habits, if any
• take only those medications that are acceptable during pregnancy and only as prescribed by a doctor
• carry out all necessary examinations

Arnold-Chiari malformation is a collective concept that refers to a group of congenital defects of the cerebellum, medulla oblongata and pons (mainly the cerebellum) and upper sections spinal cord. In a narrow sense, this disease appears to be a descent of the posterior parts of the brain to the foramen magnum - the place where the brain passes into the spinal cord.

Anatomically, the posterior and lower sections of the brain are localized in the posterior part of the skull, where the cerebellum, medulla oblongata and pons are located. Below is the foramen magnum - a large hole. Due to genetic and congenital defects, these structures are displaced downward, towards the foramen magnum. Due to such dislocation, the brain structures are damaged and neurological disorders occur.

Due to compression lower sections brain, blood flow and lymphatic drainage are disrupted. This can lead to brain swelling or hydrocephalus.

The incidence of the pathology is 4 people per 1000 population. The timeliness of diagnosis depends on the type of disease. For example, one of the forms can be diagnosed immediately after the birth of a baby, while another type of anomaly is diagnosed accidentally during routine examinations using magnetic resonance imaging. Middle age Patient 2 is from 25 to 40 years old.

In more than 80% of cases, the disease is combined with syringomyelia, a pathology of the spinal cord in which hollow cysts form in it.

Pathology can be congenital or acquired. Congenital is more common and manifests itself on early years child's life. The acquired variant is formed due to slowly growing cranial bones.

Will they be accepted into the army with an anomaly: on the list of contraindications for military service No Arnold-Chiari disease.

Is disability granted: the question of whether disability is granted depends on the degree of displacement of the cerebellar tonsils. So, if they do not fall lower than 10 mm, disability is not given, since the disease is asymptomatic. If the lower parts of the brain are lowered, the issue of granting disability depends on the severity of the clinical picture.

Prevention of the disease is nonspecific, since there is no single cause for the development of the disease. Pregnant women are advised to avoid stress, injury and adhere to proper nutrition during gestation. What pregnant women should not do: smoke, drink alcoholic drinks and drugs.

Life expectancy depends on the intensity of the clinical picture. Thus, types 3 and 4 anomalies are not compatible with life.

For what reasons does pathology occur?

Researchers have not yet determined the exact cause. Some researchers argue that the defect is a consequence of a small posterior cranial fossa, which is why the posterior parts of the brain simply have “nowhere to go”, so they are displaced downward. Other scientists say that Arnold-Chiari malformation develops due to an overly large brain, which, with its volume and mass, pushes the lower structures into the foramen magnum.

A birth defect may be latent. A downward displacement can be provoked, for example, by cerebral hydrocele, which increases pressure inside the skull and pushes the cerebellum and brainstem downward. Injuries to the skull and brain also increase the likelihood of developing a defect or create conditions for the brain stem to shift to the foramen magnum.

Clinical picture

The disease and its symptoms are based on three pathophysiological mechanisms:

1. Compression of the stem structures of the lower parts of the brain and upper parts of the spinal cord.
2. Compression of the cerebellum.
3. Impaired circulation of cerebrospinal fluid in the area of ​​the foramen magnum.

The first pathophysiological mechanism leads to disruption of the structure of the spinal cord and the functional ability of the nuclei of the lower parts of the brain. The structure and function of the nuclei of the respiratory and cardiovascular centers are disrupted.

Compression of the cerebellum leads to impaired coordination and the following disorders:

• Ataxia is a violation of coordination in the movements of different muscles.
• Dysmetria is a violation of motor acts due to the fact that spatial perception is disrupted.
• Nystagmus is oscillatory rhythmic eye movements with high frequency.

The third mechanism - a violation of the utilization and waste of cerebrospinal fluid - leads to increased pressure inside the skull and develops hypertension syndrome, manifested by the following symptoms:

1. Bursting and aching headache, worsening with changes in head position. Cephalgia is localized mainly in the back of the head and upper neck. The pain also increases with urination, defecation, coughing and sneezing.
2. Autonomic symptoms: loss of appetite, increased sweating, constipation or diarrhea, nausea, dizziness, shortness of breath, palpitations, short-term losses consciousness, sleep disturbance.
3. Mental disorders: emotional lability, irritability, chronic fatigue, nightmares.

Types

Congenital anomalies are divided into four types. The type of defect is determined by the degree of displacement of the stem structures and the combination of other malformations of the central nervous system.

1 type

Type 1 disease in adults is characterized by the fact that parts of the cerebellum descend below the level of the foramen magnum in the back of the head. It is more common than other types. Characteristic symptom the first type is the accumulation of cerebrospinal fluid in the spinal cord.

The first type of anomaly is often combined with the formation of cysts in the tissues of the spinal cord (syringomyelia). The big picture anomalies:

• bursting headache in the neck and back of the head, which gets worse when coughing or overeating;
• vomiting, which does not depend on food intake, as it is of central origin (irritation of the vomiting center in the brain stem);
• stiffness of the neck muscles;
• speech disorder;
• ataxia and nystagmus.

When the lower structures of the brain are displaced below the level of the foramen magnum, the clinic is supplemented and has the following symptoms:

1. Visual acuity decreases. Patients often complain of double vision.
2. Systemic dizziness, in which the patient feels as if objects are spinning around him.
3. Tinnitus.
4. A sudden short-term cessation of breathing, from which a person immediately wakes up and takes a deep breath.
5. Short-term loss of consciousness.
6. Dizziness when taken suddenly vertical position from horizontal.

If the anomaly is accompanied by the formation of cavity structures in the spinal cord, clinical pictures and is complemented by impaired sensitivity, paresthesia, weakening of muscle strength and disruption of the pelvic organs.

2 type and 3 type

The clinical picture of type 2 anomaly is very similar to type 3 anomaly, so they are often combined into one course. Arnold-Chiari malformation grade 2 is usually diagnosed after the first minutes of a baby’s life and has the following clinical picture:

• Noisy breathing accompanied by whistling.
• Periodic complete stops of breathing.
• Violation of the innervation of the larynx. Paresis of the laryngeal muscles occurs and the act of swallowing is disrupted: food does not enter the esophagus, but into the nasal cavity. This manifests itself from the first days of life during feeding, when milk comes back through the nose.
• Chiari malformation in children is accompanied by nystagmus and increased tone skeletal muscles, mainly increasing the tone of the muscles of the upper extremities.

Anomaly of the third type is incompatible with life due to gross defects in the development of brain structures and their downward displacement. Type 4 anomaly is hypoplasia (underdevelopment) of the cerebellum. This diagnosis is also not compatible with life.

Diagnostics

To diagnose pathology it is usually used instrumental methods diagnostics of the central nervous system. The complex uses electroencephalography, rheoencephalography and echocardiography. However, they reveal only nonspecific signs of brain dysfunction; these methods do not produce specific symptoms. The radiography used also visualizes the anomaly in insufficient volume.

Most informative method Diagnosis of a birth defect – . Second valuable diagnostic method– multispiral computed tomography. The study requires immobilization, so young children are put into artificial medicated sleep, in which they remain during the entire procedure.

MR signs of anomaly: on layer-by-layer images of the brain, displacement of the brain stem is visualized. Because of its good visualization, MRI is considered the gold standard in diagnosing Arnold-Chiari malformation.

Treatment

Surgery is one of the treatment options for the disease. Neurosurgeons use the following methods of elimination:

Cutting the filum terminale

This method has advantages and disadvantages. Advantages of cutting the final thread:

1. treats the cause of the disease;
2. reduces the risk of sudden death;
3. no after surgery postoperative complications and death;
4. the removal procedure lasts no more than one hour;
5. eliminates the clinical picture, increasing the patient’s quality of life;
6. reduces intracranial pressure;
7. improves local blood circulation.

Disadvantages of the method:

• after 3-4 days, pain is present in the surgical area.

Craniectomy

The second operation is craniectomy. Advantages:

1. eliminates the risk of sudden death;
2. eliminates the clinical picture and improves a person’s quality of life.

Flaws:

• the cause of the disease is not eliminated;
• after the intervention, the risk of death remains - from 1 to 10%;
• there is a risk of postoperative intracerebral hemorrhage.

How to treat Arnold-Chiari malformation:

1. The asymptomatic course does not require either conservative or surgical intervention.
2. In case of mild clinical picture, it is indicated symptomatic therapy. For example, for headaches, painkillers are prescribed. However, conservative treatment of Chiari malformation is ineffective if the clinical picture is severe.
3. If neurological deficits are observed or the disease reduces the quality of life, neurosurgery is recommended.

Forecast

The prognosis directly depends on the type of anomaly. For example, with an anomaly of the first type, the clinical picture may not appear at all, and a person with a displacement of the brain stem will die a natural death not from the disease. How long do they live with anomalies of the third and fourth types: patients die a few months after birth.

Arnold-Chiari malformation is a malformation of the cervico-medullary junction, characterized by displacement of the cerebellar tonsils and, in some cases, the trunk and IV ventricle below the level of the foramen magnum.

Types of malformation

Chiari malformation type I is a displacement of the cerebellar tonsils down through the foramen magnum to the upper parts of the spinal cord. This type of malformation is accompanied by hydromyelia and usually appears in adolescence or adulthood. In adolescents, the main symptoms are impaired flexion and decreased strength in the hands, loss of pain and temperature sensitivity in upper half torso and arms. Adults usually complain of pain in the cervical-occipital region, which increases with coughing, as well as pain in the arms.

Chiari malformation type II is characterized by displacement of the cerebellar vermis, tonsils, fourth ventricle, and medulla oblongata (part of the brain stem) into the foramen magnum. This type, also called Arnold-Chiari malformation, is much more often accompanied by hydromyelia than type I and is almost always associated with myelomeningocele. Myelomeningocele is congenital disorder closure of the spinal cord and spine during fetal formation. Symptoms of this malformation are obvious and usually appear immediately after birth, along with short episodes of cessation of breathing, a decreased pharyngeal reflex, involuntary and rapid downward movements of the eyeballs, and decreased strength in the arms.

Chiari malformation III type consists of displacement of the cerebellum and part of the brain stem with the meninges into a meningocele, located in the cervico-occipital region.

Arnold-Chiari malformations of types II and III may be accompanied by signs of dysplasia of the nervous system: polymicrogyria, heterotopia of the cortex, hypoplasia of the subcortical ganglia, dysgenesis of the corpus callosum, pathology of the septum pellucidum, thickening of the interthalamic junction, beaking tectum (coracoid tectum), the presence of an inflection of the Sylvian aqueduct is often noted ( 55%), cysts of the foramen of Magendie, hypoplasia of the falx and tentorium of the cerebellum, hemivertebrae, low position caudal part of the spinal cord at the level of LIV-V vertebrae and below.

Etiology of the disease

The etiology of the disease is currently unclear. There is evidence of a role genetic factor in the etiology of this syndrome. Ectopic cerebellar tonsils into the foramen magnum were found in three monozygotic twins. Since the first description of Cleland's malformation in 1883, several theories have emerged. The theory, supported by the studies of Misao Nishikawa et al., is that due to paraxial dysplasia of the mesodermal layer or primary damage to the structures of the corresponding somite, an abnormally small posterior cranial fossa is formed, the hindbrain structures, filling the volume of the posterior cranial fossa and continuing to grow, descend into the occipital channel. The combination of Chiari malformation type II with meningomyelocele is due to the fact that the degree of paraxial dysplasia of the mesodermal layer in type II AK is more pronounced than in type I AK and is noted not only at the level of formation occipital bone, but also along the axis of the body at the level of formation of a number of vertebrae, which manifests itself in spina bifida, as well as in anomalies of a number of other bone structures and skeletal system generally.

Clinic

Clinical manifestations of type I AK appear most often in adolescence or mature age. These manifestations fit into the following neurological syndromes, such as cerebellobulbar, liquorohypertensive, syringomyelic, cranial nerve injury syndromes. CSF hypertensive syndrome is manifested by headache, usually suboccipital, and neck pain, aggravated by coughing, sneezing and straining, congestive discs optic nerves. Stem disorders and disorders of the functions of cranial nerves manifest themselves in the form of unstable oscillopsia, trigeminal dysesthesia, hearing loss, tinnitus, dizziness, dysphagia, respiratory arrest during sleep, periodic fainting (often associated with coughing), impaired control over heart rate, blood pressure during transition from horizontal position vertically, atrophy of half of the tongue, paralysis may be observed vocal cords, stridor, spastic or combined (more in upper limbs) tetraparesis.

Cerebellar disorders - nystagmus, dysarthria, ataxia. Symptoms associated with syringomyelic cysts are numbness, sensory disturbances, usually of a dissociated type, as well as neuroarthropathy, dysfunction pelvic organs, lack of abdominal reflexes, muscle wasting. At the same time, a number of authors note a discrepancy between the localization, extent of the cyst, cystic index (the ratio of the anteroposterior size of the cyst to that of the diameter of the spinal cord at the level of the cyst), on the one hand, and the zone of hypoesthesia, the prevalence of segmental disorders of surface sensitivity, the severity of muscle wasting and the degree of paresis - on the other. AK type II manifests itself in newborns and early childhood symptoms such as apnea, stridor, bilateral vocal cord paresis, neurogenic dysphagia with nasal regurgitation, cyanosis during feeding, nystagmus, hypotonia, weakness, spasticity in the upper extremities, which can progress to tetraplegia. Chiari malformation type III is rare, clinical manifestations its the same as with AK II.

Diagnostics

Standard X-ray examination can only reveal indirect signs AC malformations, computed tomography also does not provide clear visualization of soft tissue structures. Widespread introduction of MRI in clinical practice allowed us to solve most of the problems associated with the diagnosis of Chiari malformation. This was facilitated by good visualization of the structures of the posterior cranial fossa, craniovertebral junction, spinal cord, and the absence of artifacts from bone structures.

MRI of a patient with type I AK and sigingomyelia.

Posterior fossa landmarks used in the diagnosis of AK.d+e = slope length;S = sphenooccipital synchondrosis;d = length of the base of the sphenoidal platform from the dorsum sella and sphenooccipital synchondrosis to the clivus;e = length between synchondrosis andbase;b = length of the brainstem between the plane of the midbrain-pons junction and the medullocervical junction;a = angle of tentorium cerebellum relative to Twining's line (Twining"sline);c = cerebellar hemisphere length;DS = apex of the dorsum sella;IOP = internal occipital prominence;OP=opisthion;B=base;TW = Twining line;McR (BtoOP) = McRee line (McRae"sline).(borrowedfromDimensions of the posterior fossa in patients symptomatic for Chiari I malformation but without cerebellar tonsillar descent, Raymond F Sekula andco-author.).

Surgical treatment

Treatment of Chiari malformation and concomitant syringomyelia is only possible surgically. The operation consists of decompressing the posterior cranial fossa or installing a cerebrospinal fluid shunt for concomitant hydrocephalus.
Local decompression is performed under general anesthesia and consists of removing part of the occipital bone, as well as the posterior halves of the I and/or II cervical vertebrae to the place where the cerebellar tonsils descend. The descended cerebellar tonsils are also resected, thereby eliminating compression of the brain stem. This effective operation expands the foramen magnum and relieves compression of the brain stem, spinal cord and cerebellar tonsils. The surgery also opens the dura mater, the thick membrane that surrounds the brain and spinal cord. Into the open hard meninges a patch made of another fabric (artificial or taken from the patient) is sewn in for more free passage of cerebrospinal fluid.

Intraoperative photography. Chiari malformation type I. 1 - dystopic tonsils of the cerebellum, causing compression of the brain stem and upper parts of the spinal cord.

Intraoperative photography. Chiari malformation type I after surgical correction. 1 - cerebellar tonsils are resected and sutured with subpial sutures to the dura mater, 2 - lumen of the fourth ventricle, 3 - superior parts of the spinal cord, compression is eliminated.
Less commonly, operations are performed to drain cerebrospinal fluid from the enlarged spinal cord into the chest or abdominal cavity using a special hollow shunt with a valve or into the intrathecal space. Sometimes these operations are performed in stages.

The effectiveness of surgical decompression ranges from 50 to 85% according to various authors. It must be remembered that surgical treatment is best carried out before the development of severe neurological disorders, since after surgical treatment, restoration of functions does not occur completely or does not occur at all, and the main goal of surgery is stabilization neurological status patient and preventing further progression of the disease.