Ataxia cerebellar vestibular frontal sensitive. Ataxia - what is it? Types, causes, diagnosis, symptoms and treatment of the disease

In essence, ataxia is chaotic voluntary movements in which the movements of muscles and their antagonists are not coordinated. Lack of coordination occurs as a result of disruption of the conduction of sensations from the periphery to the higher centers of the central nervous system. An important area through which these sensations are conducted is the cerebellum.

Typically, a distinction is made between sensory and cerebellar (cerebellar) ataxia, depending on whether the afferent pathways or the cerebellum are affected. The third form is functional (psychosis,

Sensory ataxia

With sensory ataxia, peripheral irritations are not conducted from the skin, muscles and joints to the corresponding centers, as are deep sensations. It is characteristic of this type of ataxia that when the eye is checked, it stops, and when the eyes are closed, it resumes (Romberg's symptom). Sensory ataxia may be accompanied by diseases of the peripheral nerves (acute onset, numbness, “crawling”, hypotension, absence of reflexes), dorsal roots (pain, appropriate anesthesia, loss of reflexes), posterior bundle spinal cord(anaesthesia, enhanced reflexes, hypertonicity) or brain centers (hemianesthesia, hemiparesis).

The most typical clinical form sensory ataxia is the ataxia of the tabes spinal cord. In addition to the Romberg symptom, it is characterized by a peculiar gait, in which the foot appears much higher and forward than the patient intended to move it, and the thigh is higher and lateral, as a result the step is shortened, since the patient pulls the leg back, that is, a sudden throwing of the leg forward is characteristic .

The gait is uncertain, the steps are uneven. From a sitting position, patients rise with their legs wide apart, but their uncertainty is best manifested when turning, especially when moving down stairs. Patients with tabes cannot walk in the dark because there is no eye control to make walking easier. The beginning of ataxia can be noticed by forcing the patient to walk in a straight line: with ataxia this turns out to be impossible.

Sensory ataxia is characteristic of funicular myelosis; in pernicious anemia, ataxia may be the first symptom of the disease.

Sometimes ataxia can also be caused by a tumor or chronic sclerosis of the posterior bundle. In funicular myelosis, sensitivity disorders are accompanied in some cases by loss of reflexes, in others by their strengthening, Babinski's symptom; with tabes, tendon reflexes are not evoked, hypotonicity is characteristic, which is also recognized by other symptoms (stiff pupils). Hereditary spinal ataxia combines its sensory and cerebellar forms.

Cerebellar ataxia

Cerebellar (cerebellar) ataxia is a consequence or disease of the cerebellum (nystagmus, scanning speech, dizziness, muscle atonia, walking disorders) or those pathways that connect the cerebellum to the base of the skull or to the spinal cord (lateral fasciculus).

With cerebellar ataxia, not only the movements of the limbs, but also the torso become uncoordinated. The gait resembles that of drunk people. This form of ataxia is more severe than with tabes. Often the patient is completely unable to walk, and when he tries to walk, he falls. With cerebellar ataxia, patients often fall to one side, when walking they move to one side, and are unable to correctly indicate the given direction.

Cerebellar ataxia occurs with tumors, injuries, vascular lesions of the cerebellum, and sometimes with encephalitis. It can also be caused by disseminated sclerosis, cerebellar abscess, as well as senile cerebellar degeneration. Sometimes cerebellar ataxia occurs due to alcohol poisoning and is supported by chronic alcoholism.

Cerebellar ataxia can be recognized by identifying asynergia (the patient cannot coordinate the movements of different joints, so he is unable to perform movements that require the participation of several muscles), dysmetria (the patient is not able to stop a purposeful movement, having reached the goal: if, for example, he is asked reach the nose with a finger, then having reached the nose, the finger continues to move), adiadocho- or disdochokinesis (the patient cannot make several movements immediately one after another), intention tremor (excessively large amplitude of purposeful movements, as in polyinsular sclerosis).

Friedreich's ataxia

Friedreich's hereditary spinal ataxia is a disease inherited in a recessive manner, which is characterized by ataxia, loss of reflexes, muscle atrophy, scoliosis, and significant arching of the foot. All these disorders arise as a result of damage to the dorsal roots of the spinal cord, spinocerebellar tract, and pyramidal tract.

The disease always begins at a young age and is familial in nature, unlike tabes dorsalis, which begins in old age. Hereditary cerebellar ataxia of Marie is a lesion of the cerebellum itself, the pyramidal tracts remain intact. The disease begins at a young age and is accompanied by optic nerve atrophy. Both of these diseases belong to the group of hereditary-familial diseases and are similar to each other. This also includes Sanger-Brown ataxia.

Other forms of ataxia and their causes

Certain forms of ataxia can be explained by lesions of the medulla oblongata. Thrombosis of the posterior inferior cerebellar artery causes Wallenberg syndrome. Ataxia is also caused by blockage of the superior cerebellar artery, which is accompanied by involuntary movements.

Ataxia can also be caused by damage to the brain centers by poisons. Ataxia occurs with apoplexy, chorea, multiple sclerosis, damage to the optic thalamus (hemiataxia).

Of the poisons, besides alcohol, ataxia is primarily caused by barbiturates.

Ataxia, which occurs with widespread damage to the cerebellar arteries (positive Rombert's sign, walking with legs wide apart, unsteady gait, small steps), is partly cerebral and partly cerebellar in nature.

Hysterical ataxia is also common. Identifying other symptoms of hysteria in the patient helps to recognize it. The theatricality of movements raises suspicion of ataxia. It happens that the affected limb loses sensitivity. Recognizing the condition usually does not cause difficulties, but the possibility of errors should be anticipated, since such ataxia can easily be confused with initial forms multiple sclerosis (spastic paraparesis, loss of abdominal reflexes, temporal discoloration on the optic nerve nipple).

Therapeutic exercises for ataxia:

Ataxia(Greek ataxia - disorder) - impaired coordination of movements; one of the most commonly observed motor disorders. Strength in the limbs can be completely preserved. However, movements become awkward, imprecise, their continuity and consistency, balance when standing and walking are disrupted.

Highlight:

• ataxia static - imbalance when standing,
• dynamic ataxia - incoordination during movements.

Normal coordination of movements is due to the friendly and highly automated activity of several parts of the central nervous system - the cerebellum, vestibular apparatus, conductors of deep muscle sensitivity, and the frontal and temporal cortex. The central organ for coordinating movements is the cerebellum.

Clinic.

In clinical practice, it is customary to distinguish between:

• ataxia due to disruption of deep muscle sensory conductors (sensitive, or posterior columnar, ataxia);
• ataxia due to cerebellar lesions (cerebellar ataxia);
• ataxia due to damage to the vestibular apparatus (vestibular ataxia);
• ataxia with damage to the cortex of the frontal or temporo-occipital region (cortical ataxia).

Sensitive, or posterior columnar, ataxia occurs with damage to the posterior columns (gaulle and Burdach bundles), much less often - peripheral nerves, dorsal roots, thalamus optic, cortex of the parietal lobe of the brain ( tabes dorsalis, funicular myelosis, some forms of polyneuropathy, vascular disorders, tumors).

Depending on the location of the lesion, it can be expressed in all extremities or only in the legs, in one leg or arm.
The most characteristic phenomena are sensory ataxia, which occurs when the joint-muscular sense is disturbed. lower limbs. There is general instability. When walking, the patient bends his legs excessively at the knees and hip joints and with excessive force lowers them to the floor (stamping gait). Often there is a feeling of walking on a thick carpet or cotton wool. The patient tries to compensate for the violation using vision control motor function and therefore, when walking, he constantly looks at his feet. Control of vision noticeably reduces, and closing the eyes sharply increases the symptoms of ataxia. In cases of severe damage to the posterior columns, standing and walking are completely impossible.

Cerebellar ataxia observed with damage to the vermis, hemispheres and cerebellar peduncles.
In the Romberg position or when walking, the patient deviates or falls towards the affected cerebellar hemisphere. When a worm is damaged, the fall occurs in different directions, often backwards. When walking, the patient staggers and spreads his legs wide apart (drunk gait). The flank gait is sharply disrupted. The movements are awkward and sweeping. Slowing and incoordination of movements are more pronounced on the affected side. Vision control (closing and opening the eyes) has a relatively small effect on the severity of coordination disorders. Speech is impaired - it becomes slow, drawn out, jerky, and sometimes chanted. Changes in handwriting are manifested by its unevenness, sweepingness, and macrography often occurs. Usually decreases muscle tone, more on the affected side, sometimes tendon reflexes decrease.

Cerebellar ataxia is observed with tumors, vascular foci in the cerebellum and brain stem.

Vestibular ataxia develops with damage to any part of the vestibular apparatus, which includes the labyrinth, vestibular nerve, nuclei in the brain stem and the cortical center in the temporal lobe of the brain.
Characteristic signs of vestibular ataxia: systemic dizziness (it seems to the patient that all objects are moving in a certain direction), horizontal nystagmus, nausea, vomiting. The patient staggers randomly to the sides or falls. When turning the head, dizziness intensifies. The caution with which patients move their heads is noticeable.
Vestibular ataxia is observed when (poor circulation in the vertebral system), stem encephalitis, tumors of the fourth ventricle of the brain,

Cortical ataxia develops mainly when the frontal lobe of the brain is damaged due to dysfunction of the fronto-pontine-cerebellar system.
The leg contralateral to the lesion suffers the most. There is instability when walking, especially when turning, deviation in the direction opposite to the affected hemisphere. Visual control has relatively little effect on the degree of ataxia. In case of severe lesions of the frontal lobe, the patient cannot stand or walk at all (astasia-abasia).

Frontal ataxia is also accompanied by other symptoms of damage to the frontal lobe (mental changes, grasping reflex, impaired sense of smell).
Frontal ataxia is sometimes difficult to distinguish from cerebellar ataxia. The identification of evidence of hypotonia in the ataxic limb speaks in favor of cerebellar damage. The most common causes of frontal ataxia are tumors

Ataxia, or in other words, incoordination or disruption of coordination in the interaction of muscle groups, manifested by a violation of targeted static functions and movements human body. Various types of ataxia are classified.

Ataxia is considered a common pathology, which is characterized by impaired motor skills - while the strength of the limbs is completely preserved or very slightly reduced. But movements become unclear, clumsy, and imbalance occurs when walking or standing.

To implement any necessary movement, the joint activity of many muscles is required. Movement itself is ensured by mechanisms that regulate the choice of one or another muscle group, the duration and strength of each muscle contraction, as well as the sequence of their action in the motor act. In the absence of coordination in the muscles, a violation of the quality of movements, loss of proportionality of movements, and their accuracy develops. Movements become intermittent, unsmooth and clumsy. And the transition between two movements, for example, extension and flexion, becomes very difficult.

Types and symptoms of the disease

There are 5 types of ataxia: locomotor, cortical, labyrinthine, sensory, episodic and intrapsychic. Each is an episodic ataxia characterized by acute episodes of exacerbation.

Cerebellar or locomotor ataxia

Cerebellar disease leads to the development of this type of pathology. While walking, the patient spreads his legs wide and leans forward and backward. Light form diagnosed only on the condition that the patient walks strictly in a straight line with side steps. With eyes closed, coordination problems do not become more pronounced. If the disease affects the medial part of the cerebellum, the patient experiences problems with balance and walking. When the cerebral hemispheres are damaged, the patient's movements become imprecise and tremors may occur.

The main causes of cerebellar ataxia include: abscess in the cerebellum, stroke, viral encephalitis, drug poisoning.

The reasons for the formation of a chronic form of cerebellar ataxia include: degeneration of the cerebellum due to the development of oncology of the ovaries, lungs, mammary glands, neoplasm in the posterior part cranial fossa, hypothyroidism, prolapse of the tonsils in the cerebellum, alcohol poisoning cerebellum, bad heredity. The hereditary form of the pathology can occur in an autosomal recessive or autosomal dominant manner.

Cortical ataxia

It manifests itself as a disturbance in a person’s gait—the gait seems to take on a staggering character. With severe damage to the cerebral cortex, paralysis can form, and the patient loses the ability to walk or even stand. In addition, other manifestations of damage to the cerebral cortex develop, such as changes mental state, olfactory hallucinations, auditory hallucinations, memory impairment for current events and disruption of the visual organs.

Ataxia labyrinthine or vestibular

Develops in the case of pathology of the vestibular nerve or vestibular apparatus in the inner ear.

Manifestations of the vestibular type of ataxia include: nausea with vomiting, nystagmus, dizziness and hearing impairment. When turning the eyes or changing posture, the symptoms of the vestibular type of ataxia are more pronounced, while the coordination of the upper limbs does not suffer in any way.

Its development is caused by a disease of the fibers, which contain information about human postures and body position, especially in the horizontal plane.

The sensory form of ataxia can be provoked by the influence of the following factors on the body: pathologies of the spinal cord that damage the fibers ascending to the brain - these are tumor formations of various origins, multiple sclerosis, diseases of the vascular system, vitamin deficiencies, as a rule, a lack of vitamin B12 in the body.

This is important! Symptoms of sensory ataxia include the following: incoordination when walking in complete darkness, deterioration of reflexes in the tendons, poor balance with eyes closed, and impaired vibration sensitivity detected during examination.

A person with a sensory form of ataxia, thanks to his vision, controls his own steps, but instead of a hard surface he feels cotton wool under his feet. While walking, the patient raises his legs high and lowers them to the ground with great force.

Ataxia intrapsychic

This type of ataxia is a lack of coordination between thinking and a person’s emotions and is most often considered a manifestation of schizophrenia.

How is ataxia diagnosed?

Diagnosis of the disease is based on identifying its form and identifying a person affected by ataxia in the family.

A laboratory examination reveals an abnormal metabolism of amino acids - their concentration is too low, and their excretion in the urine also decreases.

MRI of the brain indicates atrophic processes in the brain and spinal cord, in the upper part of the skull. Using electromyography, damage to sensory fibers in peripheral nerves is diagnosed.

This is important! When differentiating ataxia from other pathologies, it is necessary to pay attention to the possibility of changing the clinical manifestations of ataxia. In medical practice, there are known cases of rudimentary types of ataxia and the development of its transitional types, when clinical signs resemble symptoms of multiple sclerosis, etc.

In order to identify hereditary ataxia, it will be necessary to implement indirect or direct DNA testing. Using molecular genetic methods, ataxia is detected, and then a DNA test is performed to determine the possibility of children inheriting the pathological gene from their parents.

Sometimes a comprehensive examination of DNA tests is required, this requires biomaterial taken from all family members.

Organization of the treatment process

Treatment of the disease is organized by a neurologist and is mainly symptomatic and includes:

• General strengthening treatment - consumption of B vitamins and other remedies.
• Complex physical exercise physical therapy, helping to strengthen muscles and normalize coordination of movements.

In addition to the described treatment, the treatment of ataxia requires correction of immunodeficiency. So, it is necessary to take a course of immunoglobulin. Radiation therapy in this situation is contraindicated, and it is also necessary to prevent excessive exposure to x-rays and prolonged exposure to open sunlight.

This is important! Medicines that restore the functioning of mitochondria, namely riboflavin, succinic acid, vitamin E, can play an important role in the healing process.

How is prevention carried out?

If you have a hereditary form of ataxia, you should avoid having children. In addition, it is necessary to abandon the possibility of concluding related marriages.

The prognosis of the described diseases rarely remains favorable. There is a slow development of disorders of the neuropsychic system of the body. More often than not, this negatively affects the patient’s performance.

But with proper organization of symptomatic therapy and prevention of infectious lesions of the body, poisoning, and injuries, a person can live for many more years.

Ataxia, which translated from Greek means disorder, is considered as a disease associated with an imbalance of voluntary movements and a violation of their coordination. The accuracy of each movement of the muscles of the limbs is the result of the coordinated work of several structures of the nervous system, which transmit impulses to each other in the direction to the muscles of the limbs from the brain and in the opposite direction from the muscle fibers to the brain, which analyzes the correctness of the movement performed. There is a certain sequence in this chain: the brain (cortex cerebral hemispheres, cerebellum) > semicircular canals of the labyrinth inner ear(vestibular apparatus) > posterior columns of the spinal cord and peripheral nerves extending from it > nerve fibers penetrating muscle tissue. When the functioning of at least one link of this chain is disrupted, the phenomenon of ataxia occurs. And depending on where exactly the failure occurred, cerebellar, sensitive, frontal, and labyrinthine ataxia are distinguished.

• Cerebellar ataxia– this is the result of a violation of the structure and/or functions of the cerebellum;
• Frontal (cortical) ataxia– this is the result of a violation of the frontal-cerebellar pathways for processing and transmitting impulses;
• Sensitive ataxia– this is the result of damage to the posterior columns of the spinal cord and peripheral nerves extending from it;
• Labyrinthine ataxia- this is the result of deviations in the functioning of the vestibular analyzer.

For each of types of ataxia Its clinical manifestations are characteristic:

Symptoms of cerebellar ataxia manifest themselves in the form of hypermetry, when the distance to the object that needs to be taken is poorly calculated, the hand travels a path much greater than necessary and misses. Another sign of cerebellar ataxia is scanned speech, when a person speaks, sometimes loudly, sometimes quietly and sharply “throwing out” words, rather than pronouncing them smoothly, often dividing words into syllables. With cerebellar ataxia, the gait changes: a person walks, swaying and weaving, like a drunk. Problems begin with rising from a “lying down” position, when it is impossible to stand up without the help of your hands, because your legs rise instead of your torso. With cerebellar ataxia, the dynamics of complex movements are disrupted, and tremor of the hands appears when they approach the target.

For frontal ataxia(cortical) motor functions and coordination of movements are impaired on the side opposite to the brain hemisphere in which the disorder occurred. Frontal ataxia manifests itself in the form of instability of the body when turning, bending or turning the body. A person is virtually unable to move without relying on any objects. In addition, other functions of the nervous system are disrupted, the sense of smell disappears, and the psyche degrades (a grasping reflex appears).

Symptoms of sensitive ataxia are reflected in a person’s gait when, when walking, he greatly increases the amplitude of the leg swing and walks, throwing his legs to the sides. When in a “standing” position with legs closed and eyes closed, the person’s torso begins to sway in different directions.

For labyrinthine ataxia horizontal nystagmus appears (constant rapid movement of the eyes from side to side), dizziness and many symptoms characteristic of a malfunction of the vestibular analyzer.

Causes of ataxia, if they do not have a genetic origin (or other anomalies in the development of the body), then they are associated with a number of past or in the process of developing diseases, with a lack of vitamins, with injuries, with intoxications of the body medicines or chemical harmful substances, with infections, with neoplasms located in places where they interfere with the smooth functioning of the nervous system, with stroke, with hyperthermia (or sunstroke).

Cause of cerebellar ataxia may become tumors, multiple sclerosis, toxic effects and vitamin deficiencies.

Cause of frontal ataxia There may be injuries, tumors, inflammatory processes.

Cause of sensitive ataxia most often there are injuries or tumors of the spinal cord and its branches, a lack of vitamin B12.

Cause of labyrinthine ataxia become chronic diseases ear, encephalitis, Meniere's disease, multiple sclerosis.

Treatment of ataxia– this is the hard work of a sick person and the correct therapy of a neurologist. Therapy is carried out with anticholinesterase drugs, cerebrolysin, ATP, vitamin therapy with drugs containing group B. Sometimes drugs are prescribed to correct immunity. As a rule, it is not ataxia itself that is treated, but the diseases that contribute to its development.

If the cause of ataxia is an operable tumor or an operable aneurysm, then surgical treatment with removal of the traumatic factor.

Special sets of exercises aimed at training coordination of movements, skiing, and Nordic walking play a major role in the treatment of ataxia.

The prognosis for treatment of ataxia depends on whether ataxia is hereditary or an abnormal phenomenon, and what specific diseases it is caused by.

Ataxia is a violation of coordination in the work of a group of muscles responsible for coordination. This is reflected in the difficulty for patients to maintain balance when standing, walking and any movement. For such a disease, pronounced changes in the muscles of the limbs are not characteristic; the reasons for which it occurs are central.

An exception is the concept of intrapsychic ataxia, adopted in psychiatry. This definition denotes a discrepancy between a person’s ideas and his emotional state and is a sign of schizophrenia. For example, he rejoices imagining that he is being tortured.

Control over the correctness and coherence of the work of the torso and limbs is carried out in various parts of the nervous system, and depending on the location of the damage, various types of ataxia are distinguished.

Types of ataxia

A distinction is made between static ataxia, when maintaining balance is impossible in a standing position, and dynamic ataxia (difficulty in movement).

For a practicing physician, there is a convenient classification of this pathology:

1. Acute ataxia. Occurs in vascular accidents or certain neoplasms with a stroke-like course, multiple sclerosis, infectious encephalitis, severe metabolic disorders, obstructive hydrocephalus, intoxication, conditions accompanied by a sharp rise in temperature.
2. Subacute ataxia (develops over several weeks). The cause may be any extensive process or toxic lesions.
3. Chronic progressive ataxia. These include spinocerebellar and cortical types of ataxia, as well as cerebellar ataxia, which occurs with involvement of the pathological process other parts of the nervous system.
4. Episodic ataxia. In childhood, it is observed as a process caused by a hereditary autosomal dominant disease. For adults, the appearance of such a symptom may indicate the consequences of transient ischemic attack, neoplasms of the brain with compression of its structures at the level of the foramen magnum, multiple sclerosis.

Cerebellar ataxia

This is the name of the general term various types coordination disorders due to cerebellar damage. Features of the clinical picture depend on the degree, location and type of damage to this structural formation.

Symptoms of this ataxia can be very varied. There is unsteadiness of gait, slowness and awkwardness in movement, scanned or drawn out speech. Visual control does not improve. When walking, the patient places his legs wide and can make deep bends back or forward.

If the process affects the cerebellar hemispheres, then hand tremor becomes a very typical symptom. The handwriting of such a patient also changes; it becomes sweeping and illegible. Missing the target and increasing trembling while approaching it are noted.

In children, cerebellar ataxia occurs as a hereditary pathology of an autosomal recessive or autosomal dominant type.

Sensory ataxia

Occurs due to disruption of the posterior columns (fibers) of the spinal cord, which analyze information from peripheral receptors of the joints and skin, spinal nerves, serving as conductors of signals from these sensitive endings, the thalamus. Damage to these structures occurs as a result

• tumor formation;
• multiple sclerosis;
• disease associated with vascular damage;
• vitamin deficiency (lack of B vitamins).

Sensory ataxia manifests itself as a “stamping” gait. A person loses the feeling of support; a step is achieved by disproportionately bending the leg at the joints and lowering it down with excessive force, since the patient feels that it seems to be falling through when walking.

If the process involves upper limbs, then with outstretched arms such a patient experiences obsessive movements in the fingers (pseudoathetosis).

The difference between sensitive and other types of ataxia is that the condition worsens in the absence of visual control (with eyes closed or poor lighting).

Cortical ataxia

It appears when the frontal lobe of the cerebral cortex is damaged. For this type of ataxia, the clinical picture is expressed in the manifestation of instability of gait and turns of the body, as well as a strong bend or fall to the side corresponding to the side of the lesion. With extensive changes, the patient is completely unable to walk or even stand. Vision control does not improve coordination.

Often cortical ataxia is accompanied by a symptom complex characteristic of dysfunction of the frontal lobe: changes in mental state, the appearance of a grasping reflex, lack of smell, the appearance of hallucinations, including visual ones.

The main difference between cortical and cerebellar ataxia is a pronounced decrease in tone in the limb with impaired function.

Frontal (cortical) ataxia occurs as a result of an abscess, tumor formation, acute disorder blood circulation

Labyrinth form

Vestibular, or labyrinthine ataxia, occurs due to disturbances in the structure of one of the links that form the vestibular apparatus. This may be the cortical center of the temporal lobe, the nucleus in the brainstem, the labyrinth or the vestibular nerve.

Clinical symptoms characteristic of this type of ataxia are manifested in the appearance of dizziness, which intensifies when changing position, turning the head or torso. Often it is observed even while lying down and with eyes closed. All these signs may be accompanied by nausea and vomiting.

The patient makes any movements with great care and as smoothly as possible. Nystagmus and hearing impairment, gross changes in coordination when standing or sitting are often noted, but such a phenomenon as locomotor ataxia is not observed (with the involvement of the limbs), and speech remains normal.

Vestibular or labyrinthine ataxia occurs after encephalitis involving the brain stem, ear diseases, and as a result of a tumor process. Often this symptom accompanies Meniere's disease.

Psychogenic ataxia

It can also be noted separate species ataxia - psychogenic or hysterical. This symptom is characterized by pretentiousness of human movements. His walking resembles ice skating or walking with stilts. The disorder is functional in nature and is not confirmed by the detection of organic pathology.

Psychogenic ataxia is characterized by the following features:

• the patient’s complaints are very colorful, and their description does not correspond to the severity of the real condition;
• Often the disease is preceded by stressful situations, when going into illness seems the best way avoidance of decision making;
• the clinical picture is not typical, which makes diagnosis difficult;
• combination of the patient’s personal characteristics with work in the medical field (“trying on the disease”);
• frequent visits by the patient to doctors of various specialties.