How to cure ataxia. Paraneoplastic cerebellar degeneration. Treatment of cerebellar ataxia

"Ataxia" Literally translated from Greek, it means "disorder". However, our current understanding of the term lies in poorly coordinated movements associated mainly with damage to the cerebellum and/or cerebellar connections. In addition to cerebellar ataxia (which accounts for most cases of ataxia in clinical practice), there are also cases of so-called sensitive and vestibular ataxia, caused respectively by damage to the spinal proprioceptive pathways and the vestibular system.

Clinical manifestations of various types of ataxia

Cerebellar ataxia

Clinically, cerebellar ataxia manifests as an unsteady and wobbly gait with an extended base, as well as incoordination and clumsiness of movements, dysarthria (scanded, jerky speech), saccade dysmetria, and oscillations. Patients usually stand with their feet wide apart, when they try to put their feet closer together, they begin to sway or even fall, due to unstable balance, support or reliance on surrounding objects is required. Even small manifestations of ataxia of walking can be detected in the so-called tandem walking in a straight line. Ataxia can be generalized or predominantly disrupt walking, movements in the arms, legs, speech, eye movements; may be one-sided or involve both parties. Ataxia is often accompanied by muscle hypotonia, slowness of movement, intention tremor (an action tremor that increases in amplitude as the target approaches), impaired control of complex multi-joint movements (asynergy), increased postural reflexes, nystagmus (usually horizontal in cerebellar ataxia), and some cognitive and affective changes (the so-called "cerebellar cognitive-affective syndrome", usually caused by acute, rather large ischemic damage to the posterior lobe of the cerebellum). It should be emphasized that motor disorders in ataxia are usually not associated with muscle weakness, hyperkinesis, spasticity, etc., however, all of them, as well as other additional symptoms, can complicate the clinical picture of the disease. In turn, severe ataxia can be the main cause of disability and social maladaptation.

Relatively isolated trunk ataxia with impaired standing and walking is observed with limited lesions of the cerebellar vermis (patients deviate or fall forward with rostal lesions of the vermis and backward with caudal lesions). Ataxia in the extremities is usually attributed to the defeat of the cerebellar hemispheres, saccadic dysmetria - to dysfunction of the dorsal parts of the worm. Unilateral damage to the cerebellum is manifested by disorders on the side of the same name: such patients stand with a lowered ipsilateral shoulder, stagger and deviate when walking towards the damage, coordinating tests also reveal ataxia in the involved arm and leg. Although in humans there is no strict correspondence between certain parts of the body and areas of the cerebellar hemispheres, it is believed that damage to the anterior-upper hemispheres leads mainly to ataxia in the legs (a similar pattern is characteristic of alcoholic cerebellar degeneration), while the posterolateral parts of the hemispheres are associated with movements in the hands. , face and speech. Ataxia can also be associated with damage to the cerebellar pathways; sometimes it manifests with rather characteristic clinical symptoms, such as, for example, a rough high-amplitude "rubral" tremor when stretching the arms in front of you (typically for damage to the dentato-rubral loop, for example, in multiple sclerosis or Wilson-Konovalov's disease).

Sensitive ataxia

Compared with cerebellar ataxia, sensitive ataxia is quite rare. Usually it is a consequence of damage to the posterior columns and, accordingly, a violation of proprioceptive afferentation (for example, in Friedreich's disease, vitamin E and B12 deficiency, neurosyphilis). Sensitive ataxia can be diagnosed by a distinct proprioceptive deficit and a marked increase in symptoms when the eyes are closed. Sometimes in such cases, you can notice the phenomenon of "pseudoathetosis" in the affected limb.

vestibular ataxia

Vestibular dysfunction can cause a syndrome referred to as "vestibular" (or "labyrinthine") ataxia. In fact, this syndrome can be considered a specific subtype of sensitive ataxia. Patients with vestibular ataxia show gross impairment of walking and standing (vestibular imbalance), but without involvement of the limbs and speech. With unilateral lesions of the labyrinth, the "flank gait" in the direction of damage is significantly impaired. This type of ataxia is often accompanied by dizziness, vomiting, and hearing loss.

Pathophysiology

Pathophysiologically, cerebellar ataxia is a failure of the normal anti-inertial mechanisms that are responsible for the smoothness, uniformity, and precision of movement.

Under physiological conditions, any voluntary movement is the result of precisely coordinated and organized activity of many antagonistic and synergistic muscles. Coordinated in space and time, the interaction between different muscles is realized through bilateral connections of the cerebellum with different levels of the central nervous system involved in the performance of motor functions (motor cortex zones, basal ganglia, brainstem nuclei, reticular formation, spinal cord motor neurons, proprioceptive neurons and pathways ). Being the main coordinating center of movements, the cerebellum receives information in advance about any changes in muscle tone and positions of body parts, as well as about any planned actions. Using this forward-looking information, the cerebellum corrects muscle activity, exerts fine motor control, and ensures precise movement. Therefore, diseases affecting the cerebellum lead to desynchronization of muscle contractions, which is clinically manifested by confused irregular "jolts" - chanted speech, intentional tremor, dysmetria, trunk titubation and other cerebellar phenomena.

Atactic disorders in lesions of the cerebellum

Lesions of the cerebellum and cerebellar tracts can be caused by acute or chronic pathology (see table).

Acute ataxia

Repetitive paroxysms of acute ataxia are observed with periodic (episodic) ataxia. These hereditary diseases are caused by genetic defects in ion channels (calcium, potassium), which in turn lead to impaired excitability of neurons. Some patients with atactic seizures may respond well to acetazolamide (acetazolamide-sensitive forms of periodic ataxia). Periodic ataxias belong to the group of so-called channelopathies.

Chronic ataxia

Chronic ataxia can be caused by a number of different diseases (see table) of both genetic and non-genetic nature. Chronic or subacute cerebellar ataxia, especially at a young age, is a typical manifestation of multiple sclerosis, the diagnosis of which is confirmed by a remitting course and multiple foci of demyelination in the brain and spinal cord on MRI. It should always be remembered that chronic or subacute cerebellar ataxia can be caused by a tumor (among the tumors characteristic of the cerebellum are cerebellopontine schwannoma, medulloblastoma and hemangioblastoma), normotensive hydrocephalus (Hakimi-Adams syndrome) and paraneoplastic cerebellar degeneration (lung cancer and other systemic neoplasms); All these diseases require appropriate and timely surgical treatment. Cerebellar degeneration can also be caused by chronic alcoholism, hypothyroidism, celiac disease, vitamin B12 deficiency, heat stroke, abuse of certain drugs with anxiolytic, hypnotic and anticonvulsant effects.

Chronic progressive ataxia is a key feature of degenerative atactic syndromes, both hereditary and sporadic.

Hereditary ataxias are a clinically and genetically heterogeneous group of diseases transmitted most often in an autosomal dominant or autosomal recessive manner.

For autosomal dominant ataxias (ASAs), 28 loci on different chromosomes have been mapped to date, and 14 genes and their protein products have been identified. In most autosomal dominant SCA, mutations are pathological intragenic expansions of trinucleotide repeats ("dynamic" mutations). The most common is the expansion of CAG repeats, which are translated at the protein level into a proportional elongation of the polyglutamine region of the protein (hence the name "polyglutamine" diseases and the specific mechanism of neurodegeneration). There is an inverse correlation between the number of trinucleotide repeats in the mutant gene and the age of disease onset; moreover, the longer the expansion, the more severe the clinical symptoms. In addition to dynamic mutations, SCAs can also be caused by point mutations in genes encoding, for example, protein kinase gamma, fibroblast growth factor, and a number of other proteins. The frequency of occurrence of certain forms of autosomal dominant SCA in different populations is different. For example, in Russia, more than 40% of families with dominant SCA are associated with mutations in the ATXN1 gene on chromosome 6p (SCA1), while in most Western European countries, mutations in the ATXN3 gene (SCA3 or Machado-Joseph disease) predominate.

Among autosomal recessive and X-linked recessive ataxias, the most common Friedreich's ataxia is caused by the expansion of GAA repeats in the non-coding region of the FRDA gene on chromosome 9q. The protein product of this gene, frataxin, is thought to be involved in mitochondrial iron homeostasis. Thus, Friedreich's disease is a Mendelian form of mitochondrial cytopathies. Usually the disease manifests quite early (up to 20 years) and is manifested by mixed sensory-cerebellar ataxia, dysarthria, muscle weakness, cardiomyopathy, skeletal deformities, diabetes, and a steadily progressive course. There is a fairly strong correlation between the length of expansion and the clinical manifestations of Friedreich's disease, so a relatively late onset and a "benign" course are characteristic of a short expansion of GAA repeats.

Sporadic (idiopathic) degenerative ataxia is a heterogeneous group, which in turn includes parenchymal cortical cerebellar atrophy and olivopontocerebellar atrophy. The latter is now regarded as a form of multiple system atrophy, a severe neurodegenerative disease characterized by the involvement of a number of cerebral and spinal systems (cerebellum, basal ganglia, brainstem, autonomic nuclei of the spinal cord and motor neurons) and the presence of specific alpha-synuclein-positive glial cytoplasmic inclusions.

Diagnosis

In patients with atactic disorders, the diagnosis is based primarily on neuroimaging (CT, MRI) and neurophysiological (evoked potentials, electroneuromyography, etc.) studies that provide data on the structural and functional characteristics of the central and peripheral nervous system. In most cases of hereditary ataxia, verification of the diagnosis using DNA analysis is now available both for the patients themselves and for their clinically healthy relatives from the "risk" group. To prevent new cases of the disease in these families, medical genetic counseling and prenatal DNA diagnostics can be carried out.

In patients with sporadic ataxia, it is necessary to search for all possible somatic disorders that can cause cerebellar symptoms (neoplasms, endocrine diseases, etc.). Ataxia can be a manifestation of a number of metabolic diseases (see table), so appropriate biochemical screening should be performed.

Treatment

The treatment and prognosis of atactic syndromes is based on their cause. With the existence of a radial treatment (such as surgery for cerebellar tumors or correction of vitamin deficiency), one can expect a complete or partial recovery, or at least a cessation of further progression.

There is no direct treatment for ataxia itself. A limited beneficial effect has been reported in degenerative ataxia with amantadine, buspirone, L-5-hydroxytryptophan, thyrotropin-releasing factor and pregabalin, however, these data are not confirmed by randomized trials. There are reports of successful treatment of cerebellar tremors with isoniazid and some anticonvulsants (clonazepam, carbamazepine, and topiramate); in some cases, stereotaxic surgery on the nuclei of the thalamus is possible.

Physiotherapy is an important component in the treatment of patients with ataxia. It is aimed at preventing various complications (such as contractures and muscle atrophy), maintaining physical fitness, improving coordination and walking. Special complexes of "cerebellar" and "sensory" exercises are recommended, as well as procedures with biofeedback and stabilography.

The first approaches to gene and cell therapy of hereditary ataxias are under development; it is possible that it is these technologies that will make a significant breakthrough in treatment in the future.

Table. Causes of acute and chronic ataxia

Coordinator dysmotility due to pathology of the cerebellum. Its main manifestations include gait disorder, disproportionate and asynergic movements, dysdiadochokinesis, handwriting changes in the type of sweeping macrography. Usually, cerebellar ataxia is accompanied by chanted speech, intentional trembling, postural tremor of the head and trunk, and muscle hypotension. Diagnosis is carried out using MRI, CT, MSCT, MAG of the brain, dopplerography, analysis of cerebrospinal fluid; if necessary - genetic research. Treatment and prognosis depend on the causative disease that caused the development of cerebellar symptoms.

General information

Chronically progressive cerebellar ataxia is often the result of alcoholism and other chronic intoxications (including substance abuse and polydrug addiction), slowly growing cerebellar tumors, genetically determined cerebral degenerative and atrophic processes with damage to the tissues of the cerebellum or its conduction pathways, severe form of Chiari anomaly. Among the genetically determined progressive ataxias of the cerebellar type, Friedreich's ataxia, Nefridreich's spinocerebellar ataxia, Pierre-Marie's ataxia, Holmes's cerebellar atrophy, and olivopontocerebellar degeneration (OPCD) are the most famous.

Cerebellar ataxia with a paroxysmal course can be hereditary and acquired. Among the causes of the latter, TIA, multiple sclerosis, intermittent obstruction of the cerebrospinal fluid, transient compression in the region of the foramen magnum are indicated.

Symptoms of cerebellar ataxia

Ataxia of the cerebellar type is manifested by sweeping uncertain asynergic movements and a characteristic unsteady gait, during which the patient spreads his legs wide for greater stability. When you try to go along one line, there is a significant swing to the sides. Ataxic disorders increase with a sharp change in direction of movement or a rapid start of walking after getting up from a chair. Sweeping movements are the result of a violation of their proportionality (dysmetria). Both an involuntary stop of a motor act before its goal is achieved (hypometry), and an excessive range of motion (hypermetry) are possible. Dysdiadochokinesis is observed - the patient's inability to quickly perform opposite motor acts (for example, supination and pronation). Due to impaired coordination and dysmetria, a pathognomonic change in handwriting for cerebellar ataxia occurs: macrography, unevenness and sweeping.

Static ataxia is most evident when the patient tries to stand in the Romberg position. For the pathology of the cerebellar hemisphere, a typical deviation, and even a fall, towards the lesion, with changes in its median structures (worm), a fall is possible in any direction or backward. Carrying out a finger-nose test reveals not only a miss, but also an intentional tremor accompanying ataxia - a trembling of the fingertip, which intensifies when it approaches the nose. Testing a patient in the Romberg position with open and closed eyes shows that visual control does not significantly affect the results of the tests. This feature of cerebellar ataxia helps to differentiate it from sensitive and vestibular ataxia, in which the lack of visual control leads to a significant aggravation of impaired coordination.

Typically, cerebellar ataxia is accompanied by nystagmus and dysarthria. Speech has a specific "cerebellar" character: it loses its smoothness, slows down and becomes intermittent, stress goes to each syllable, which makes it look like a chant. Often, cerebellar-type ataxia is observed against the background of muscle hypotension and a decrease in deep reflexes. When causing tendon reflexes, pendulum movements of the limb are possible. In some cases, titubation occurs - a low-frequency postural tremor of the trunk and head.

Diagnosis of cerebellar ataxia

Since the pathology of the cerebellum can have a wide variety of etiologies, specialists from various fields are involved in its diagnosis: traumatologists, neurosurgeons, oncologists, geneticists, endocrinologists. A thorough examination of the neurological status by a neurologist makes it possible to determine not only the nature of the cerebellar ataxia, but also the approximate area of ​​the lesion. So, the pathology in the cerebellar hemisphere is evidenced by hemiataxia, the one-sided nature of coordination disorders and a decrease in muscle tone; about the pathological process in the cerebellar vermis - the predominance of walking and balance disorders, their combination with cerebellar dysarthria and nystagmus.

In order to exclude vestibular disorders, a study of the vestibular analyzer is carried out: stabilography, vestibulometry, electronystagmography. If an infectious lesion of the brain is suspected, a blood test for sterility is done, and PCR studies are performed. Lumbar puncture with a study of the obtained cerebrospinal fluid allows you to identify signs of hemorrhage, intracranial hypertension, inflammatory or tumor processes.

The main methods for diagnosing diseases underlying the pathology of the cerebellum are neuroimaging methods: CT, MSCT and MRI of the brain. They make it possible to detect tumors of the cerebellum, post-traumatic hematomas, congenital anomalies and degenerative changes in the cerebellum, its prolapse into the foramen magnum and compression when adjacent anatomical structures are displaced. In the diagnosis of ataxia of a vascular nature, MRA and Dopplerography of cerebral vessels are used.

Hereditary cerebellar ataxia is established by the results of DNA diagnostics and genetic analysis. The risk of having a child with a pathology in a family where cases of this disease have been noted can also be calculated.

Treatment of cerebellar ataxia

Fundamental is the treatment of the causative disease. If cerebellar ataxia has an infectious and inflammatory genesis, it is necessary to prescribe antibacterial or antiviral therapy. If the cause lies in vascular disorders, then measures are taken to normalize blood circulation or stop cerebral bleeding. For this purpose, in accordance with the indications, angioprotectors, thrombolytics, antiplatelet agents, vasodilators, anticoagulants are used. With ataxia of toxic origin, detoxification is performed: intensive infusion therapy in combination with the appointment of diuretics; in severe cases - hemosorption.

Hereditary ataxias do not yet have a radical treatment. Metabolic therapy is carried out mainly: vitamins B12, B6 and B1, ATP, meldonium, ginkgo biloba preparations, piracetam, etc. Massage is recommended for patients to improve metabolism in skeletal muscles, increase its tone and strength.

Cerebellar and posterior fossa tumors often require surgical treatment. Removal of the tumor should be as radical as possible. When establishing the malignant nature of the tumor, an additional course of chemotherapy or radiotherapy is prescribed. With regard to cerebellar ataxia due to occlusion of the CSF pathways and hydrocephalus, shunt operations are used.

Forecast and prevention

The prognosis depends entirely on the cause of cerebellar ataxia. Acute and subacute ataxias caused by vascular disorders, intoxication, inflammatory processes, with timely elimination of the causative factor (vascular occlusion, toxic effects, infection) and adequate treatment, can completely regress or partially remain in the form of residual effects. Chronically progressive, hereditary ataxias are characterized by an increasing aggravation of symptoms, leading to the patient's disability. Ataxias associated with tumor processes have the most unfavorable prognosis.

Preventive in nature is the prevention of injuries, the development of vascular disorders (atherosclerosis, hypertension) and infection; compensation of endocrine and metabolic disorders; genetic counseling when planning a pregnancy; timely treatment of the pathology of the cerebrospinal fluid system, chronic cerebral ischemia, Chiari syndrome, processes of the posterior cranial fossa.

Cerebellar ataxia is a syndrome that occurs when a special structure of the brain called the cerebellum, or its connections with other parts of the nervous system, is damaged. Cerebellar ataxia is very common and can be the result of a wide variety of diseases. Its main manifestations are a disorder of coordination of movements, their smoothness and proportionality, imbalance and maintenance of body posture. Some signs of the presence of cerebellar ataxia are visible to the naked eye even to a person without a medical education, while others are detected using special tests. Treatment of cerebellar ataxia largely depends on the cause of its occurrence, on the disease of which it is a consequence. About what can cause the occurrence of cerebellar ataxia, what symptoms it manifests itself and how to deal with it, you will learn by reading this article.

The cerebellum is a part of the brain located in the posterior cranial fossa below and behind the main part of the brain. The cerebellum consists of two hemispheres and the vermis, the middle part that unites the hemispheres with each other. The average weight of the cerebellum is 135 g, and the size is 9-10 cm × 3-4 cm × 5-6 cm, but despite such small parameters, its functions are very important. None of us think about what muscles need to be strained in order, for example, to simply sit down or stand up, take a spoon in hand. It seems to happen automatically, you just have to want it. However, in fact, to perform such simple motor acts, the coordinated and simultaneous work of many muscles is required, which is feasible only with the active functioning of the cerebellum.

The main functions of the cerebellum are:

• maintaining and redistributing muscle tone to keep the body in balance;
• coordination of movements in the form of their accuracy, smoothness and proportionality;
• maintaining and redistributing muscle tone in synergistic muscles (performing the same movement) and antagonist muscles (performing multidirectional movements). For example, to bend the leg, it is necessary to simultaneously tighten the flexors and relax the extensors;
• economical expenditure of energy in the form of minimal muscle contractions necessary to perform a particular type of work;
• participation in the processes of motor learning (for example, the formation of professional skills associated with the contraction of certain muscles).

If the cerebellum is healthy, then all these functions are carried out imperceptibly for us, without requiring any thought processes. If some part of the cerebellum or its connections with other structures is affected, then the performance of these functions becomes difficult, and sometimes simply impossible. That's when the so-called cerebellar ataxia occurs.

The spectrum of neurological pathology that occurs with signs of cerebellar ataxia is very diverse. Causes of cerebellar ataxia can be:

• disorders of cerebral circulation in the vertebrobasilar basin (and, dyscirculatory encephalopathy);
• and bridge-cerebellar angle;
• with damage to the cerebellum and its connections;
• , meningoencephalitis;
• degenerative diseases and anomalies of the nervous system with damage to the cerebellum and its connections (, and others);
• intoxications and metabolic disorders (for example, alcohol and drug use, lead intoxication, diabetes mellitus, and so on);
• overdose of anticonvulsants;
• vitamin B12 deficiency;
• obstructive.

Symptoms of cerebellar ataxia

It is customary to distinguish two types of cerebellar ataxia: static (static-locomotor) and dynamic. Static cerebellar ataxia develops with damage to the cerebellar vermis, and dynamic - with pathology of the cerebellar hemispheres and its connections. Each type of ataxia has its own characteristics. Cerebellar ataxia of any kind is characterized by a decrease in muscle tone.

Static-locomotor ataxia

This type of cerebellar ataxia is characterized by a violation of the antigravitational function of the cerebellum. As a result, standing and walking become too much of a burden on the body. Symptoms of static-locomotor ataxia can be:

• inability to stand straight in the “heels and toes together” position;
• falling forward, backward or swaying to the side;
• the patient can only stand with his legs wide apart and balancing with his hands;
• staggering gait (like a drunk);
• when turning the patient "carries" to the side, and he may fall.

Several simple tests are used to detect static-locomotor ataxia. Here is some of them:

• standing in the Romberg position. The pose is as follows: the toes and heels are moved together, the arms are extended forward to a horizontal level, the palms are looking down with the fingers spread wide. First, the patient is asked to stand with his eyes open, and then with his eyes closed. With static-locomotor ataxia, the patient is unstable both with open eyes and with closed ones. If no deviations are found in the Romberg position, then the patient is offered to stand in the complicated Romberg position, when one leg must be placed in front of the other so that the heel touches the toe (maintaining such a stable posture is possible only in the absence of pathology from the cerebellum);
• the patient is offered to walk along a conditional straight line. With static-locomotor ataxia, this is impossible, the patient will inevitably deviate in one direction or another, spread his legs wide apart, and may even fall. They are also asked to stop abruptly and turn 90 ° to the left or right (with ataxia, the person will fall);
• the patient is offered to walk with a side step. Such a gait with static-locomotor ataxia becomes, as it were, dancing, the body lags behind the limbs;
• test "asterisk" or Panov. This test allows you to identify violations with a mildly pronounced static-locomotor ataxia. The technique is as follows: the patient must consistently take three steps forward in a straight line, and then three steps back, also in a straight line. First, the test is carried out with open eyes, and then with closed ones. If with open eyes the patient is more or less able to perform this test, then with closed eyes he inevitably turns around (there is no straight line).

In addition to impaired standing and walking, static-locomotor ataxia manifests itself as a violation of coordinated muscle contraction when performing various movements. This is called in medicine cerebellar asynergia. To identify them, several tests are also used:

• The patient is asked to sit up abruptly from a prone position with arms folded across his chest. Normally, at the same time, the muscles of the trunk and the posterior thigh muscles contract synchronously, and the person is able to sit down. With static-locomotor ataxia, synchronous contraction of both muscle groups becomes impossible, as a result of which it is impossible to sit down without the help of hands, the patient falls back and simultaneously raises one leg. This is the so-called Babinsky's asynergy in the prone position;
• Babinsky's asynergy in a standing position is as follows: in a standing position, the patient is offered to bend back, throwing his head back. Normally, for this, a person will have to involuntarily bend his knees slightly and straighten in the hip joints. With static-locomotor ataxia, neither flexion nor extension occurs in the corresponding joints, and an attempt to bend ends in a fall;
• Ozhechovsky's test. The doctor extends his arms with palms up and invites the standing or sitting patient to lean on them with his palms. Then the doctor suddenly pulls his hands down. Normally, lightning-fast involuntary contraction of the muscles in the patient contributes to the fact that he either leans back or remains motionless. A patient with static-locomotor ataxia will not succeed - he will fall forward;
• the phenomenon of the absence of a reverse shock (positive Stuart-Holmes test). The patient is offered to bend the arm in the elbow joint with force, and the doctor counteracts this, and then suddenly stops the counteraction. With static-locomotor ataxia, the patient's hand is thrown back with force and hits the patient's chest.

Dynamic cerebellar ataxia

In general, its essence lies in the violation of the smoothness and proportionality, accuracy and dexterity of movements. It can be bilateral (with damage to both hemispheres of the cerebellum) and unilateral (with pathology of one hemisphere of the cerebellum). Unilateral dynamic ataxia is much more common.

Some of the symptoms of dynamic cerebellar ataxia overlap with those of static locomotor ataxia. So, for example, this concerns the presence of cerebellar asynergia (asynergy of Babinsky lying and standing, tests of Ozhechovsky and Stuart-Holmes). There is only a slight difference: since dynamic cerebellar ataxia is associated with damage to the cerebellar hemispheres, these tests predominate on the side of the lesion (for example, if the left cerebellar hemisphere is affected, “problems” will be with the left limbs and vice versa).

Also, dynamic cerebellar ataxia manifests itself:

• intenion tremor (tremor) in the extremities. This is the name of the trembling that occurs or intensifies towards the end of the movement performed. At rest, trembling is not observed. For example, if you ask the patient to take a ballpoint pen from the table, then at first the movement will be normal, and by the time the pen is taken directly, the fingers will tremble;
• misses and misses. These phenomena are the result of disproportionate muscle contraction: for example, the flexors contract more than necessary to perform a particular movement, and the extensors do not relax properly. As a result, it becomes difficult to perform the most familiar actions: bring a spoon to your mouth, fasten buttons, lace up shoes, shave, and so on;
• handwriting violation. Dynamic ataxia is characterized by large uneven letters, a zigzag orientation of the written;
• scrambled speech. This term refers to the discontinuity and jerkiness of speech, the division of phrases into separate fragments. The speech of the patient looks as if he is speaking from the podium with some slogans;
• nystagmus. Nystagmus is an involuntary tremulous movement of the eyeballs. In fact, this is the result of discoordination of contraction of the eye muscles. The eyes seem to twitch, this is especially pronounced when looking to the side;
• adiadochokinesis. Adiadochokinesis is a pathological movement disorder that occurs in the process of rapid repetition of multidirectional movements. For example, if you ask the patient to quickly turn the palms against their axis (as if screwing in a light bulb), then with dynamic ataxia, the affected hand will do it more slowly and awkwardly compared to the healthy one;
• the pendulum nature of the knee jerks. Normally, a blow with a neurological hammer under the patella causes a single movement of the leg of one degree or another. With dynamic cerebellar ataxia, leg oscillations are made several times after one blow (that is, the leg swings like a pendulum).

To identify dynamic ataxia, it is customary to use a number of samples, since the degree of its severity does not always reach significant limits and is immediately noticeable. With minimal lesions of the cerebellum, it can be detected only with samples:

• finger test. With a straightened and raised to a horizontal level hand with a slight abduction to the side with open and then closed eyes, ask the patient to put the tip of the index finger into the nose. If a person is healthy, he can do this without much difficulty. With dynamic cerebellar ataxia, the index finger misses, when approaching the nose, intentional trembling appears;
• finger test. With eyes closed, the patient is offered to hit each other with the tips of the index fingers of slightly apart hands. Similar to the previous test, in the presence of dynamic ataxia, no hit occurs, trembling may be observed;
• thumb test. The doctor moves the neurological hammer in front of the patient's eyes, and he should hit the index finger exactly in the gum of the hammer;
• test with hammer A.G. Panov. The patient is given a neurological hammer in one hand and the fingers of the other hand are offered to alternately and quickly squeeze the hammer either by the narrow part (handle), or by the wide one (gum);
• heel-knee test. It is carried out in the supine position. It is necessary to raise the straightened leg by approximately 50-60 °, hit the heel with the knee of the other leg and, as it were, “ride” the heel along the front surface of the lower leg to the foot. The test is carried out with open eyes, and then with closed ones;
• test for redundancy and disproportion of movements. The patient is asked to stretch his arms forward to a horizontal level with palms up, and then, at the doctor's command, turn his palms down, that is, to turn clearly 180 °. In the presence of dynamic cerebellar ataxia, one of the arms rotates excessively, that is, more than 180 °;
• test for diadochokinesis. The patient should bend his arms at the elbows and, as it were, take an apple in his hands, and then quickly make twisting movements with his hands;
• Doinikov's finger phenomenon. In the sitting position, the patient has relaxed hands on his knees, palms up. On the affected side, it is possible to bend the fingers and turn the hand due to an imbalance in the tone of the flexor and extensor muscles.

Such a large number of samples for dynamic ataxia is due to the fact that it is not always detected using only one test. It all depends on the extent of damage to the cerebellar tissue. Therefore, for a more in-depth analysis, several samples are usually carried out simultaneously.

Treatment of cerebellar ataxia

There is no single strategy for the treatment of cerebellar ataxia. This is due to the large number of possible causes of its occurrence. Therefore, first of all, it is necessary to establish the pathological condition (for example, stroke or multiple sclerosis) that led to cerebellar ataxia, and then a treatment strategy is being built.

The symptomatic remedies most commonly used for cerebellar ataxia include:

Help in the fight against cerebellar ataxia is exercise therapy and massage. Performing certain exercises allows you to normalize muscle tone, coordinate the contraction and relaxation of the flexors and extensors, and also helps the patient to adapt to new conditions of movement.

In the treatment of cerebellar ataxia, physiotherapeutic methods can be used, in particular electrical stimulation, hydrotherapy (baths), magnetotherapy. Classes with a speech therapist will help normalize speech disorders.

In order to facilitate the process of movement, a patient with severe manifestations of cerebellar ataxia is recommended to use additional means: canes, walkers and even wheelchairs.

In many ways, the prognosis for recovery is determined by the cause of cerebellar ataxia. So, in the presence of a benign tumor of the cerebellum after its surgical removal, a complete recovery is possible. Cerebellar ataxias associated with mild circulatory disorders and craniocerebral injuries, meningitis, meningoencephalitis are successfully treated. Degenerative diseases, multiple sclerosis are less amenable to therapy.

Thus, cerebellar ataxia is always a consequence of some kind of disease, and not always neurological. Its symptoms are not so numerous, and its presence can be detected with the help of simple tests. It is very important to establish the true cause of cerebellar ataxia in order to cope with the symptoms as quickly and effectively as possible. The tactics of managing the patient is determined in each case.

Neurologist M. M. Shperling talks about ataxia:

Cerebellum(in lat. cerebellum) in humans is located inside the skull, in the region of the back of the head. Typically, the cerebellum has an average volume of 162 cubic meters. cm, and its weight varies between 135-169 g. There are two hemispheres in the cerebellum, between which is its most ancient part - worm . In addition, with the help of three pairs of legs, it is connected with the medulla oblongata, with the bridge and the midbrain. It consists of white and gray matter, from the latter the cerebellar cortex and paired nuclei in its body are formed. The worm is responsible for the balance and stability of the body, and the hemispheres are responsible for the accuracy of movements. To maintain the balance of the body, the cerebellum receives information from the proprioceptors of various parts of the body and from other organizations that are involved in controlling the position of the human body ( bottom olives , vestibular nuclei ).

With the tension of muscle groups when performing purposeful actions, maintaining the body position in balance, they enter the cerebellum nerve impulses . They run from the spinal cord and from the part of the cerebral cortex that is responsible for movement. After going through a complex system of contacts, the flow of nerve impulses enters the cerebellum, which, in turn, analyzes it and gives out an “answer”, which already enters the human mind, i.e. in the cerebral cortex and spinal cord. Thanks to the coordinated work of all organs, the work of the muscles of the body becomes clear and beautiful. Lesions of the cerebellum and its vermis are manifested in static disorders, i.e. a person cannot stably maintain a stable position of the center of gravity of the body, as well as balance.

The term " ataxia ” with respect to diseases of the nervous system has been used since the time of Hippocrates, and then it meant “disorder” and “confusion”, today they understand ataxia incoordination. Ataxia is manifested in a disorder of gait and movements of the limbs, which manifests itself in trembling when performing actions, overshooting, as well as imbalance in standing and sitting body positions.

There are ataxias cerebellar , sensitive , vestibular and frontal . When the cerebellum and its pathways are damaged, cerebellar ataxia occurs. This disease is manifested by symptoms of ataxia when standing and walking. The gait of a patient with cerebellar ataxia resembles that of a drunkard, he walks unsteadily, spreads his legs wide, throws him from side to side, usually in the direction of the location of the pathological focus.

In the limbs intentional, a person cannot quickly change the position of the body. It can also often be seen asynergy , that is, inconsistency of movements, for example, when the body is tilted back, the legs do not bend at the knee joints, so a fall is possible. Very often, with cerebellar ataxia, “chopped” speech is observed, according to warehouses, changes in handwriting can be observed, sometimes - muscular hypotension .

If the lesion extends to the hemispheres of the cerebellum, then ataxia of the extremities may develop on the side in which the hemisphere is located, if the worm is affected, then ataxia of the trunk develops.

If a patient with cerebellar ataxia is placed in Romberg's pose (that is, to stand up with legs tightly moved, hands pressed to the body and raised head), then this posture is unstable, the human body can sway, sometimes pulling one side, up to a fall. If the worm is affected, then the patient falls back, and if one of the hemispheres is affected, then towards the pathological focus.

In a normal state, if there is a threat of falling to the side, the leg located on the side of the fall moves in the same direction, and the other one comes off the floor, that is, a "jump reaction" occurs. Cerebellar ataxia disturbs these reactions, if he is pushed slightly to the side, he falls easily ( pushing symptom ).

At a young age, the human nervous system has a fairly high potential neuroplasticity, i.e. the property of the nervous system to quickly rebuild under the influence of external or internal changes. For the development of neuroplasticity, a series of repetitions of the same impact is necessary, due to which biochemical and electrophysiological changes occur in the central nervous system. As a result of this, new contacts are formed between the CNS cells, or old contacts become active. And with ataxia, due to damage to the nerve tissues, the skills of fine and harmonious movements cannot be formed.

It should be noted that ataxias occur in approximately 1 to 23 people per 100,000 (prevalence varies by region). The development of ataxia itself is usually genetically determined, and the symptoms of congenital cerebellar ataxia appear in childhood.

According to modern classifications, cerebellar ataxias are:

• (non-progressive, when the hemispheres or cerebellar vermis are underdeveloped or absent).
• Autosomal recessive ataxias arising at an early age (). Friedreich's ataxia was first described in 1861, and its symptoms usually appear in children or young people under 25 years of age. The disease also manifests itself in symptoms of ataxia, static disorders, unsteady gait, and decreased muscle tone. The resulting disorder of sensitivity leads to a decrease in tendon reflexes. Friedreich's ataxia is characterized by an abnormal development of the skeleton, the appearance of "Friedreich's foot", i.e. shortening of the foot, its high arch. The disease itself progresses quite slowly, but leads to disability of patients, and bedriddenness.
• Recessive ataxias associated with the X chromosome ( X-chromosomal ataxia ). This type of ataxia is very rare, mainly in males in the form of progressive cerebellar insufficiency.
• Betten's disease, inherited in an autosomal recessive manner, is a congenital disease. It is characterized by congenital cerebellar ataxia, which is transmitted in the first years of life in the form of a violation of statics, coordination of movements and gaze. Such children begin to hold their heads by the age of 2-3, and walk and talk even later. With age, the patient adapts to his condition.
• Autosomal dominant ataxias late age (they are also called spinocerebellar ataxias). This includes Pierre Marie's disease . This type of hereditary cerebellar ataxia appears at the age of 25-45 years, and affects the cells of the cortex and nuclei of the cerebellum, spinocerebellar pathways in the spinal cord and nuclei of the brain bridge. Its signs are ataxia and pyramidal insufficiency, intentional trembling, tendon hyperreflexia, "chopped" speech. Sometimes - ptosis, decreased vision. The size of the cerebellum gradually decreases, very often there is a decrease in intelligence and depressive states. By the way, most authors consider Pierre Marie's cerebellar ataxia to be a syndrome, which includes olivopontocerebellar (Dejerine-Thomas) and olivocerebellar atrophy (Holmes type), cerebellar atrophy of Marie-Foy-Alajouanine, as well as Lhermitte's olivorubrocerebellar atrophy.

Symptoms of congenital cerebellar ataxia

Common symptoms for all types of ataxias are ataxic manifestations. This is a violation of the coordinated work of all muscles to achieve the goal of the act of movement. Symptoms of congenital cerebellar ataxia include dysmetria - disproportionate efforts to perform a purposeful movement. Dyssynergy is observed when the coordination of individual muscles is disturbed, intentional trembling, rhythmic deviation from the correct trajectory of purposeful movement, which increases when approaching the target.

Frequent signs of instability in an upright position, nystagmus (rhythmic rapid movements of the eyeball), as well as jerky speech, stress on each syllable. A symptom of cerebellar ataxia in children is that the child begins to sit and walk late, and his gait is unsteady, the child seems to be “shaking”.

Symptoms of congenital cerebellar ataxia are manifested by a delay in the motor functions of the child, he begins to sit, walk late, there is a lag in mental development, speech delay. Usually by the age of 10, compensation of brain functions occurs.

To confirm the diagnosis, it is necessary to CT and MRI studies , as well as DNA research to determine the genes that lead to the development of certain forms of pathologies.

Treatment of congenital cerebellar ataxias

The treatment of the disease includes the implementation of activities for the motor and social rehabilitation of patients, so that the patient adapts to his defect. Recommended physical therapy classes, walking training, classes with a speech therapist, training on stabilometric platform .

Sometimes, depending on the type of ataxia, medical treatment of congenital cerebellar ataxia with the use of muscle relaxants may be carried out, nootropics , anticonvulsant drugs. To treat Pierre Marie's disease, drugs are used to reduce muscle tone (, meliktin , kondelfin ).

Ataxia with acute onset

1. Strokes and volumetric processes with pseudo-stroke course.
2. Multiple sclerosis
3. Guillain-Barré syndrome
4. Encephalitis and postinfectious cerebellitis
5. Intoxication (including medicinal: lithium, barbiturates, diphenin)
6. metabolic disorders
7. hyperthermia
8. Obstructive hydrocephalus

Ataxia with subacute onset (within a week or several weeks)

1. Tumors, abscesses and other volumetric processes in the cerebellum
2. normotensive hydrocephalus
3. Toxic and metabolic disorders (including those associated with malabsorption and nutrition).
4. Paraneoplastic cerebellar degeneration
5. Multiple sclerosis

Chronically progressive ataxias (over several months or years)

1. Spinocerebellar ataxias (usually with early onset)

• Friedreich ataxia
• "Nefridreykhovskaya" ataxia with early onset with preserved reflexes, hypogonadism, myoclonus and other disorders

2. Cortical cerebellar ataxias

• Cortical atrophy of the cerebellum Holmes
• Late cerebellar atrophy Marie-Foy-Alajouanina

3. Cerebellar ataxia with a late onset, involving the structures of the brain stem and other formations of the nervous system

• Dentato-rubro-pallido-Lewis atrophy
• Machado Joseph disease
• Other degenerations involving the cerebellum
• Cerebellar dysgenesis

Paroxysmal episodic ataxia

In childhood:

• Autosomal dominant hereditary periodic ataxia (type 1 and type 2, differing in the duration of attacks).
• Other ataxias (Hartnup disease; pyruvate dehydrogenase deficiency; maple syrup disease)

• Medicinal
• Multiple sclerosis
• transient ischemic attacks
• Compression processes in the area of ​​the large occipital foramen
• Intermittent obstruction of the ventricular system

Cerebellar ataxia with acute onset

Stroke appears to be the most common cause of acute ataxia in clinical practice. Lacunar pons and supratentorial infarcts can cause ataxia, usually in the pattern of atactic hemiparesis. Ischemia in the thalamus, posterior knee of the internal capsule, and corona radiata (area of ​​blood supply from the posterior cerebral artery) may present with cerebellar ataxia. At the same time, "silent" lacunar infarctions are often found in the cerebellum. Cerebellar infarction may also present with isolated vertigo. Cardiac embolism and atherosclerotic occlusion are the two most common causes of cerebellar stroke.

Hemiataxia with hemihypesthesia are characteristic of strokes in the thalamus (a branch of the posterior cerebral artery). An isolated atactic gait sometimes occurs when the penetrating branches of the basilar artery are affected. Hemiataxia involving certain cranial nerves develops when the upper parts of the pons varolii (superior cerebellar artery), the lower lateral parts of the pons and the lateral parts of the medulla oblongata (anterior inferior and posterior inferior cerebellar arteries) are affected, usually in the picture of stem alternating syndromes.

Extensive cerebellar infarcts or hemorrhages are accompanied by the rapid development of generalized ataxia, dizziness and other stem and cerebral manifestations, often in connection with the development of obstructive hydrocephalus.

Tumors of the cerebellum, abscesses, granulomatous and other volumetric processes sometimes manifest themselves acutely and without severe symptoms (headaches, vomiting, mild ataxia when walking).

Multiple sclerosis sometimes develops acutely and rarely occurs without cerebellar symptoms. There are usually other signs (clinical and neuroimaging) of a multifocal lesion of the brain stem and other parts of the nervous system.

Guillain-Barré syndrome occurs as a rare lesion involving the cranial nerves and ataxia. But even here, at least mildly expressed hyporeflexia, an increase in protein in the cerebrospinal fluid, is detected. Miller Fisher's syndrome is acute with the development of ataxia, ophthalmoplegia and areflexia (other symptoms are optional), followed by a good recovery of impaired functions. These manifestations are very specific and sufficient for clinical diagnosis.

Encephalitis and postinfectious cerebellitis often involve the cerebellum. Cerebellitis in mumps is especially common in children with premorbid cerebellar anomalies. Chickenpox can cause cerebellitis. Epstein-Barr virus causes infectious mononucleosis with secondary acute cerebellar ataxia. Acute post-infectious ataxia is especially common among the consequences of childhood infections.

Intoxications are another common cause of acute ataxias. As a rule, there is an atactic gait and nystagmus. If ataxia is found in the extremities, it is usually symmetrical. The most common causes: alcohol (including Wernicke's encephalopathy), anticonvulsants, psychotropic drugs.

Metabolic disorders such as insulinoma (hypoglycemia causes acute ataxia and confusion) are fairly common causes of acute ataxia.

Hyperthermia in the form of prolonged and intense heat stress (high fever, heat stroke, neuroleptic malignant syndrome, malignant hyperthermia, lithium intoxication hyperthermia) can affect the cerebellum, especially in the rostral region around the vermis.

Obstructive hydrocephalus, which developed acutely, is manifested by a whole range of symptoms of intracranial hypertension (headache, drowsiness, stunning, vomiting), among which acute cerebellar ataxia often occurs. With the slow development of hydrocephalus, ataxia can occur with minimal cerebral disorders.

Ataxia with subacute onset

Tumors (especially medulloblastomas, astrocytomas, ependymomas, hemangioblastomas, meningiomas, and schwannomas (of the pontocerebellar angle), as well as abscesses and other masses in the cerebellar region, may present clinically as subacute or chronically progressive ataxias. In addition to increasing cerebellar ataxia, symptoms of involvement of neighboring formations; signs of increased intracranial pressure appear relatively early. Diagnostic assisted by neuroimaging techniques.

Normotensive hydrocephalus (Hakim-Adams syndrome: progressive enlargement of the ventricles with normal CSF pressure) is clinically manifested by a characteristic triad of symptoms in the form of dysbasia (apraxia of walking), urinary incontinence and dementia of the subcortical type, which develop over several weeks or months.

Main reasons: consequences of subarachnoid hemorrhage, meningitis, traumatic brain injury with subarachnoid hemorrhage, brain surgery with bleeding. Idiopathic normotensive hydrocephalus is also known.

Differential Diagnosis carried out with Alzheimer's disease, Parkinson's disease, Huntington's chorea, multi-infarct dementia.

Toxic and metabolic disorders (deficiency of vitamin B12, vitamin B1, vitamin E; hypothyroidism, hyperparathyroidism; intoxication with alcohol, thallium, mercury, bismuth; overdose of diphenin or other anticonvulsants, as well as lithium, cyclosporine and some other substances) can lead to progressive cerebellar ataxia.

Paraneoplastic cerebellar degeneration. Malignancy may be accompanied by subacute (sometimes acute) cerebellar syndrome, often with tremor or myoclonus (and also opsoclonus). Often it is a tumor of the lungs, lymphoid tissue or female genital organs. Paraneoplastic cerebellar degeneration clinically sometimes outstrips the direct manifestations of the tumor itself. Unexplained subacute (or chronic) cerebellar ataxia sometimes requires a focused oncological search.

Multiple sclerosis should be confirmed or ruled out in subacute cerebellar ataxia, especially in those under 40 years of age. If the clinical picture is not typical or doubtful, then MRI and evoked potentials of different modalities usually resolve this issue.

Chronically progressive cerebellar ataxias (over several months or years)

In addition to slowly growing tumors and other voluminous processes, this group is characterized by:

Spinocerebellar ataxias (early onset)

Spinocerebellar ataxias are a group of diseases, the list of which is not strictly fixed and includes, according to different authors, various hereditary diseases (especially in childhood).

Friedreich's ataxia (typical symptoms: cerebellar ataxia, sensitive ataxia, hyporeflexia, Babinsky's symptom, scoliosis, Friedreich's foot (pes cavus), cardiomyopathy, diabetes mellitus, axonal polyneuropathy).

Spinocerebellar degeneration of the “non-Friedreich type”. Unlike Friedreich's ataxia, an earlier onset of the disease, preserved tendon reflexes, and hypogonadism are characteristic here. In some families - lower spastic paraparesis or other signs of a predominant lesion of the spinal cord.

Cortical cerebellar ataxias

Holmes' cortical atrophy of the cerebellum is a hereditary disease of adults, manifested by slowly progressive cerebellar ataxia, dysarthria, tremor, nystagmus, and, rarely, other neurological signs (isolated cerebellofugal familial atrophy, heredoataxia type B). On MRI - atrophy of the cerebellar vermis.

Marie-Foy-Alajouanine tardive cerebellar atrophy begins late (mean age 57 years) and progresses very slowly (over 15-20 years), largely resembling the previous form (clinically and morphologically), but without a family history (isolated cerebellofugal atrophy of the sporadic type ). Similar pathological and clinical manifestations have been described in alcoholic cerebellar degeneration.

Late-onset cerebellar ataxia involving brain stem structures and other structures of the nervous system

Olivopontocerebellar atrophy (OPCA)

There are various classifications of OPCA. The sporadic form (Dejerine-Thoma) looks like a clinically "clean" type or like a type with extrapyramidal and autonomic (progressive autonomic failure) manifestations. The latter option is referred to as multiple system atrophy. Hereditary forms (approximately 51%) of OPCA (type A heredoataxia) pathomorphologically and sometimes clinically (unlike sporadic forms, PVN is not characteristic here) differ little from sporadic forms of OPCA and today there are seven genetic variants.

The leading manifestation of any form of OPCA is cerebellar ataxia (on average, more than 90% of patients), especially noticeable in walking (more than 70%); dysarthria (scanded speech, dysphagia, bulbar and pseudobulbar disorders); parkinsonism syndrome occurs in approximately 40-60% of cases; pyramidal signs are no less characteristic. Separate clinical variants include myoclonus, dystonia, choreic hyperkinesis, dementia, oculomotor and visual disorders in their manifestations; rarely - amyotrophy, fasciculations and other (epileptic seizures, apraxia of the eyelids) symptoms. In recent years, sleep apnea in OPCA has been increasingly described.

CT or MRI reveals atrophy of the cerebellum and brain stem, expansion of the fourth ventricle and cistern of the cerebellopontine angle. The parameters of auditory stem evoked potentials are often violated.

Differential Diagnosis carried out within various forms of multisystem atrophy (sporadic OPCA, Shy-Drager syndrome, strionigral degeneration). The range of diseases with which it is necessary to differentiate OPCA includes such diseases as Parkinson's disease, progressive supranuclear palsy, Huntington's chorea, Machado-Joseph's disease, Friedreich's ataxia, ataxia-telangiectasia, Marinesco-Sjogren's syndrome, abetalipoproteinemia, CM2 gangliosidosis, Refsum's disease , metachromatic leukodystrophy, adrenoleukodystrophy, Creutzfeldt-Jakob disease, paraneplastic cerebellar degeneration and, sometimes, Alzheimer's disease, diffuse Lewy body disease and others.

Dento-rubro-pallido-Lewis atrophy is a rare familial disease, described mainly in Japan, in which cerebellar ataxia is associated with choreoathetosis and dystonia and, in some cases, includes myoclonus, parkinsonism, epilepsy, or dementia. Accurate diagnosis is carried out by molecular genetic analysis of DNA.

Machado-Joseph disease (Azores disease) is an autosomal dominant disorder characterized by slowly progressive cerebellar ataxia in adolescence or early adulthood, associated with hyperreflexia, extrapyramidal rigidity, dystonia, bulbar signs, distal motor weakness, and ophthalmoplegia. Interfamilial variability of individual neurological manifestations is possible. Accurate diagnosis is achieved by genetic analysis of DNA.

Other hereditary ataxias involving the cerebellum. There are a large number of descriptions of hereditary cerebellar ataxias with unusual clinical features (cerebellar ataxia with optic nerve atrophy; with pigmentary retinal degeneration and congenital deafness; retinal degeneration and diabetes mellitus; Friedreich's ataxia with juvenile parkinsonism; etc.).

This group also includes the so-called "ataxia plus" syndromes (Hippel-Lindau disease; ataxia-telangiectasia; "cerebellar ataxia plus hypogonadism"; Marinescu-Sjogren's syndrome; "cerebellar ataxia plus hearing loss") and diseases with a known biochemical defect (disease Refsum; Bassen-Kornzweig disease), as well as some other rare diseases (Lie's disease; Gerstmann-Straussler disease); Creutzfeldt-Jakob disease; X-linked adrenoleukodystrophy; MERRF syndrome; Tay-Sachs disease; Gaucher disease; Niemann-Pick disease; Sandhof's disease).

Cerebellar dysgenesis

Arnold-Chiari malformation is manifested by protrusion of the tonsils of the cerebellum into the foramen magnum. Type I of this malformation reflects the mildest protrusion and is manifested by headache, neck pain, nystagmus (especially downward), atactic dysbasia, and involvement of the inferior cranial nerves, as well as the conduction systems of the trunk. Type IV is the most severe and presents with cerebellar hypoplasia with cystic enlargement of the fourth ventricle. This type overlaps with Dandy-Walker syndrome, which can include many other brain abnormalities.

Such variants of cerebellar dysgenesis have also been described, such as congenital hypoplasia of the granular cell layer; agenesis of the cerebellar vermis.

Paroxysmal (episodic) ataxia

In childhood

Familial episodic (paroxysmal) ataxia exists in two forms.

Type I begins at 5-7 years of age and is characterized by short attacks of ataxia or dysarthria lasting from a few seconds to several minutes. In the interictal period, myokymia is detected, which is usually observed in the circular muscles of the eyes and hands. Seizures are usually triggered by a startle or physical exertion. In some families, seizures respond to anticonvulsants. Other findings include joint contractures and paroxysmal dyskinesias. On EMG - constant activity of motor units.

Type II episodic ataxia is characterized by attacks lasting up to several days. Attacks are provoked by emotional stress and physical exertion. The disease often begins at school age. In some patients, attacks are accompanied by migraine-like headache, dizziness and nausea, that is, a picture that forces us to exclude basilar migraine. In the interictal period, nystagmus is typical, beating down. In some cases, progressive cerebellar ataxia may occur. MRI sometimes shows selective atrophy of the cerebellar vermis.

Hartnup's disease is a rare disease with an autosomal recessive type of inheritance, which consists in a violation of tryptophan metabolism. It is characterized by intermittent cerebellar ataxia. Symptoms develop over several days and last from a week to a month. Children with this disease are characterized by increased photosensitivity of the skin (photodermatosis). Many patients have episodes of cerebellar ataxia, sometimes accompanied by nystagmus. Neurological manifestations are provoked by stress or intercurrent infections, as well as a diet containing tryptophan. The current is favorable. characteristic aminoaciduria. Seizures are prevented by oral daily administration of niconitamide (25 to 300 mg per day).

Pyruvate dehydrogenase deficiency. Most patients show mild developmental delay in early childhood. Attacks of ataxia, dysarthria, and sometimes hypersomnia usually begin after 3 years of age. In more severe forms, episodes of ataxia begin in infancy and are accompanied by generalized weakness and impaired consciousness. Some seizures develop spontaneously; others are provoked by stress, infections. Cerebellar dyscoordination attacks recur at irregular intervals and can last from 1 day to several weeks. Characterized by lactic acidosis and recurrent polyneuropathy. The concentration of lactate and pyruvate always rises during attacks. When loading with glucose per os, hyperglycemia is of a prolonged nature and the concentration of lactate in the blood increases. This test can trigger clinical symptoms.

Maple syrup disease is inherited in an autosomal recessive manner and consists in a violation of amino acid metabolism. Clinical manifestations become noticeable at the age of 5 months to 2 years: episodes of ataxia, irritability and increasing hypersomnia appear. Causing factors: infections, surgery, and a protein-rich diet. The duration of attacks is variable; most children recover spontaneously, but some die with severe metabolic acidosis. In survivors, psychomotor development remains normal. The diagnosis is based on general clinical data and the detection of a specific sweet smell of urine. In the blood serum and in the urine, the amino acids leucine, isoleucine and valine are found in large quantities (they give this smell to the urine). The differential diagnosis is carried out with phenylketonuria and other hereditary anomalies of amino acid metabolism.

Episodic ataxia in adults

Medicinal (toxic) ataxia has already been mentioned above. Its occurrence is often due to the accumulation or overdose of drugs such as diphenin and other anticonvulsants, certain psychotropic drugs (lithium) and other drugs. Multiple sclerosis with a relapsing course at the time of exacerbations (as well as pseudo-relapses) can be manifested by intermittent ataxia. Transient ischemic attacks, manifested by cerebellar ataxia, are characteristic of damage to the vertebral and basilar arteries (including in the picture of basilar migraine).

Compression processes in the area of ​​the foramen magnum can also be manifested by episodes of cerebellar ataxia.

Intermittent obstruction of the ventricular system in some neurosurgical diseases, among other neurological manifestations, also contains episodes of cerebellar ataxia.

The presented syndromic-nosological analysis of cerebellar ataxias concerns the main forms of neurological diseases that occur with ataxia, but it is not and can hardly be completely complete. Therefore, we additionally present another classification of cerebellar ataxia, in which the etiology (rather than clinical signs) formed the basis of the classification. It contains, first of all, a detailed list of diseases and can serve as an aid to the previous clinical classification in the differential diagnosis of cerebellar ataxia.