How many proteins are included in the complement system? Complement regulatory mechanisms

The cerebellum is part of the central nervous system, located under cerebral hemispheres brain It has the following formations: two hemispheres, legs and a worm. Responsible for coordination of movements and muscle function. With lesions of the cerebellum, symptoms manifest themselves as motor disturbances, changes in speech, handwriting, gait, and loss of muscle tone.

Causes of cerebellar diseases

The causes of cerebellar diseases can be injuries, congenital underdevelopment of this structure, as well as circulatory disorders, the consequences of drug addiction, substance abuse, neuroinfections, and intoxication. There is a congenital defect in the development of the cerebellum caused by a genetic pathology called Marie's ataxia.

Important! Damage to the cerebellum can result from strokes, injuries, cancer, and intoxication.

Cerebellar injuries are observed with fractures of the base of the skull and injuries to the occipital part of the head. Impaired blood supply to the cerebellum occurs with atherosclerotic vascular damage, as well as with ischemic, hemorrhagic stroke of the cerebellum.

Cerebellum, i.e. hemorrhage due to a violation of the integrity of the vessel is a common cause of movement, speech, and eye symptoms. Hemorrhages into the cerebellar substance occur when high blood pressure and hypertensive crises.

In older people, the vessels are not elastic, are affected by atherosclerosis and are covered with calcified cholesterol plaques, so they cannot withstand high pressure and their wall is torn. The result of hemorrhage is ischemia of the tissues that received nutrition from the ruptured vessel, as well as the deposition of hemosiderin in the intercellular substance of the brain and the formation of a hematoma.

Oncological diseases associated directly with the cerebellum, or with metastases, also cause disorders of this structure. Sometimes lesions of the cerebellum are caused by a violation of the outflow of cerebral fluid.

The key symptom of cerebellar damage is. It manifests itself in trembling of the head and the whole body at rest and during movement, incoordination of movements, and muscle weakness. Symptoms of cerebellar diseases can be asymmetrical if one of the hemispheres is damaged. The main manifestations of pathology in patients are identified:

, one of the symptoms of cerebellar damage, manifests itself in sweeping movements and excessive amplitude at the end.
– trembling of the head and body at rest.
Dysdiadochokinesis manifests itself in the inability to quickly opposing movements muscles - flexion and extension, pronation and supination, adduction and abduction.
Hypometry is the stopping of a motor act without achieving its goal. Hypermetry is an increase in pendulum-like movements when approaching the achievement of the goal of the movement.
Nystagmus is an involuntary movement of the eyes.
Muscle hypotension. The patient's muscle strength decreases.
Hyporeflexia.
Dysarthria. Scanned speech, i.e. patients emphasize words rhythmically and not in accordance with the rules of orthoepy.
Gait disturbance. Shaky movements of the body do not allow the patient to walk in a straight line.
Handwriting disorders.

Diagnosis and treatment of cerebellar disorders

The neurologist examines and tests superficial and deep reflexes. Electronystagmography and vestibulometry are performed. Assign general analysis blood. A lumbar puncture is performed to detect infection in the cerebrospinal fluid, as well as markers of stroke or inflammation. The head is held. The condition of the cerebellar vessels is determined using Dopplerography.

Treatment of cerebellar diseases in ischemic stroke is carried out using thrombus lysis. Fibrinolytics (streptokinase, alteplase, urokinase) are prescribed. To prevent the formation of new blood clots, antiplatelet agents (aspirin, clopidogrel) are used.

For ischemic and hemorrhagic strokes, metabolic drugs (Mexidol, Cerebrolysin, Cytoflavin) improve metabolism in brain tissue. To prevent recurrent strokes, drugs that lower blood cholesterol are prescribed, and in case of hemorrhagic hemorrhage, antihypertensive drugs are prescribed.

Neuroinfections (encephalitis, meningitis) require antibiotic therapy. Pathologies of the cerebellum caused by intoxications require detoxification therapy, depending on the nature of the poisons. Forced diuresis, peritoneal dialysis and hemodialysis are performed. When food poisoning– gastric lavage, administration of sorbents.

For oncological lesions of the cerebellum, treatment is carried out in accordance with the type of pathology. Chemotherapy, radiation therapy, or surgical treatment are prescribed. If the outflow of cerebrospinal fluid is disrupted, causing cerebellar syndrome, an operation is performed with craniotomy and shunting of the pathways for the outflow of cerebrospinal fluid.

Conclusion

Damage to the cerebellum, the consequence of which can be disability, the patient’s need for care, requires timely and thorough treatment, as well as care and rehabilitation of the patient. If there is a sudden disturbance in gait or speech disorder, it is necessary to visit a neurologist.

The cerebellum is located in the posterior cranial fossa above the medulla oblongata and the pons, separated from the occipital lobes above by the tentorium cerebellum. Anatomically, the cerebellum consists of a phylogenetically more ancient vermis and two hemispheres (Fig. 11, 12).

The cerebellar vermis is connected to the trunk and determines static coordination (control of posture, tone, body balance and supporting movements), and the hemispheres are connected to the limbs and coordinate their movements. The cerebellum receives a copy of the afferent information transmitted from the spinal cord to the cerebral cortex (muscle tone, position of the body and limbs in space), as well as a copy of the efferent information from the motor centers of the cerebral cortex to the spinal cord (necessary position of the body or limbs in space) and compares them. If deviations are detected, the cerebellum immediately reports them to the motor centers, thus continuously correcting voluntary and automatic movements.

The cerebellum has a cortex (gray matter), white matter and a group of nuclei - an accumulation of gray matter deep in the white matter (Fig. 13). There are a dentate nucleus (nucl. dentatus), a spherical nucleus (nucl. globosus), a cork-shaped nucleus (nucl. emboliformis) and a tent nucleus (nucl. fastigii).

Rice. eleven. Cerebellum, superior view (according to P. Duus):

1 – anterior lobe; 2 – posterior lobe; 3 – primary (precival) fissure of the cerebellum; 4 – upper worm; 5 – top of the worm; 6 – slope; 7 – worm tubercle; 8 – leaf; 9 – intermediate part (paravermial zone); 10 – lateral part

Rice. 12. Cerebellum, inferior view (according to P. Duus):

1 – flocculo-nodular lobe ( A- scrap, b- nodule); 2 – cerebellar amygdala; 3 – lower worm; 4 – tubercle; 5 – pyramid; 6 – tongue; 7 – posterolateral fissure; 8 – IV ventricle; 9 – lateral aperture of the IV ventricle; 10 – cerebellar peduncles ( A– top, b– average, V– lower); 11 – slope; 12 – central lobule; 13 – uvula cerebellum; 14 – superior medullary velum; 15 – anterior lobe; 16 – periglobular lobule

Rice. 13. Structure of the cerebellar cortex with afferent and efferent connections (according to P. Duus):

1 – molecular layer; 2 – layer of Purkinje cells; 3 – granular layer; 4 – white matter; 5 – basket cells; 6 – Purkinje cells; 7 – granular cells; 8 – parallel fibers; 9 – axons of Purkinje cells; 10 – climbing fibers; 11 – neurons of the dentate nucleus; 12 – mossy fibers

Rice. 14. Afferent and efferent connections of the cerebellum (section planes: on the left - through the dentate nucleus, on the right - through the cerebellar vermis):

1 – thalamus; 2 – dentate-red nuclear and dentate-thalamic pathways; 3, 10 – cerebellopontine tract; 4 – corky nucleus; 5 – dentate nucleus; 6 – anterior and posterior spinocerebellar tracts; 7 – spinoolivary pathway; 8 – red nuclear spinal tract; 9 – olivocerebellar tract; 11 – thalamocortical pathway; 12 – cortical-pontine pathway; 13 – red kernels; 14 – central tire track; 15 – trunk kernels; 16 – reticular formation; 17 – olive; 18 – vestibular nuclei; 19 – vestibulospinal tract; 20 – reticulospinal tract; 21 – uvula cerebellum; 22 – central lobule; 23 – top of the worm; 24 – cork-shaped and spherical nuclei; 25 – tent core; 26 – clivus of the cerebellar vermis; 27 – leaf; 28 – nodule; 29 – tongue; 30 – pyramid; 31 – worm tubercle

The cerebellum has three pairs of peduncles: the upper peduncles connect it with the midbrain at the level of the quadrigeminal, the middle ones with the pons, and the lower ones with the medulla oblongata. In the superior cerebellar peduncles there is an afferent pathway from the spinal cord (anterior spinocerebellar tract, or Govers' tract) and a descending (dentate-rednuclear-spinal cord) pathway, going from the dentate nucleus of the cerebellar hemisphere through the red nucleus to the anterior horn of the spinal cord.

In the largest middle cerebellar peduncles pass the cerebellopontine fibers, which are part of the cortical-pontocerebellar tract from the superior frontal gyrus and the lower parts of the occipital and temporal lobes in the cerebellar cortex. In the lower cerebellar peduncles there are afferent tracts (posterior spinocerebellar tract, or Flexig's tract), vestibulocerebellar, bulbocerebellar (from the nuclei of the thin and cuneate fasciculi), reticulocerebellar, olivocerebellar and efferent tracts (cerebellar-reticulospinal, cerebellar-vestibulospinal, cerebellar-spinal). olivospinal) (Fig. . 14).

It should be noted that the cerebellar hemispheres are connected to the opposite hemispheres of the brain (crossing of the cortical-pontocerebellar tract) and with the halves of the spinal cord on their side (double crossing of the dentate-rednuclear-spinal cord). Therefore, with half damage to the cerebellum itself or unilateral damage to the cerebellar peduncles, the corresponding symptoms will be detected on its side (homolateral).

Functions of the cerebellum

– Anti-gravity function – maintaining and redistributing muscle tone to keep the body in balance.

– Anti-inertial function – coordination of movements in relation to their accuracy, smoothness and proportionality.

– Reciprocal innervation – maintenance and redistribution of muscle tone in synergistic and agonist muscles.

– Autonomic function– the most economical expenditure of energy when working muscles by preventing their excessive contractions.

– Cognitive function – participation in the mechanisms of synaptic plasticity, which underlies motor learning and others cognitive processes(muscle memory).

Symptoms of cerebellar lesions (cerebellar ataxia)

Static ataxia: dysfunction of maintaining balance at rest (the patient cannot stand or stands staggering) and when walking (walks staggering, spreading his legs widely, while being “thrown” from side to side), cerebellar asynergies.

Dynamic ataxia: intention tremor (kinetic tremor that increases as the limb approaches an object), hypermetria/dysmetria (redundancy/disproportion of movements), misses, adiadochokinesis (difficulty in performing fast alternately opposite movements), asynergia (impaired coordination in the actions of agonist/antagonist muscles).

In addition to the disorders detected using the above tests, when the cerebellum is damaged, disorders of other simple and complex motor acts: As a result of incoordination of the speech motor muscles, the patient’s speech slows down (bradylalia), loses smoothness, and becomes explosive (chanted speech); handwriting becomes uneven and excessively large (megalography); when looking to the sides or up, nystagmus may appear - rhythmic twitching of the eyeballs as a manifestation of intention tremor of the oculomotor muscles; when the cerebellar systems are damaged, muscle hypotonia is often observed - muscles become flaccid, joint hypermobility is possible; deep reflexes are reduced.

Static violations

Romberg test– the patient stands with his feet together, arms extended forward and eyes closed. If ataxia is present, he staggers or falls.

Complicated Romberg test(sensitized) - in addition to the previous test, the patient places his feet on the same line, one in front of the other (“tightrope walker pose”).

Standing and walking in a straight line– become almost impossible, since when walking the patient is forced to spread his legs wide apart or he deviates (falls) towards the predominance of static ataxia.

"Flank walking" walking with extended steps - the body lags behind the limbs, an abrupt stop is impossible (the patient “throws” towards the prevailing static ataxia).

Panova test– used to determine the lateralization of cerebellar disorders in patients with mild static ataxia. The patient takes three steps forward and three steps back, first with his eyes open and then with his eyes closed. A patient with cerebellar disorders, after closing his eyes, turns towards the lateralization of the cerebellar disorders.

Babinski's asynergy in the supine position. The patient sits up sharply from a lying position with his arms crossed over his chest, which is normally accompanied by a synergistic contraction of part of the muscles of the trunk and the posterior group of thigh muscles (physiological synergy of Babinsky in the supine position). With static cerebellar ataxia, the patient will not be able to sit up from a lying position due to falling backwards, as well as raising the leg(s) on the side of the lateralization of the cerebellar disorders.

Babinski's asynergy in a standing position. The patient bends back, throwing his head back. Normally, this action is accompanied by flexion at the knees and extension at the hip joints (Babinsky’s physiological synergy in a standing position). With a positive symptom, such synergies disintegrate, which leads to the patient falling backwards.

Stewart–Holmes test or the phenomenon of lack of pushback. The patient bends his arm with force at the elbow joint, and the doctor counteracts the movement. Then the opposition abruptly stops, which in a healthy person is accompanied by a so-called reverse impulse due to contraction of the antagonist muscles. In the presence of a positive test, synergistic contraction of the extensor muscles does not occur, as a result of which the patient punches himself forcefully in the chest.

Tests to detect cerebellar lesions.

Dynamic disturbances

Finger-nose test– the patient, first with eyes open and then with eyes closed, from a position of straightened and abducted arm, hits the tip of the nose with the tip of the index finger. Characterized by hypermetry (dysmetria), misses, and intentional tremor.

Finger-finger test– the patient with his eyes closed should touch the tips of his index fingers to each other. Characterized by hypermetry (dysmetria), misses, and intentional tremor.

Finger hammer test– the patient “catches up” index finger rubber band of the hammer and touches it accurately while the hammer is quickly moved into various directions. Characterized by hypermetry (dysmetria), misses, and intentional tremor.

Hammer test (Panov test)– the patient holds the neurological hammer by the handle with one hand, and fingers I and II of the other hand alternately squeeze either the narrow part of the handle or the elastic band of the hammer. Characterized by hypermetry (dysmetria) and misses.

Heel-knee test– in a supine position, the patient raises his straightened leg, then hits the knee of the other leg with his heel and, slightly touching, runs it along the lower leg to the foot, first with open and then with closed eyes. Intentional trembling and missedness are characteristic.

Test for redundancy and proportionality– the patient’s arms are extended forward in a state of supination, then the patient, at the doctor’s command, sharply turns his arms with his palms down. Excessive rotation is determined on the side of cerebellar disorders.

Test for diadochokinesis– the arms are bent at the elbow joints and slightly raised, and the hands seem to be “holding a large apple.” Next, the patient quickly and consistently performs pronation and supination of the hands, as if “screwing in light bulbs.” On the side of dynamic cerebellar ataxia, movements become slow, awkward (“clumsy”), and asynchronous.

Doinikov finger phenomenon– the patient, in a sitting position, holds his hands in a supinated position with his fingers widely spread (the hands can lie on the knees). On the side of dynamic cerebellar ataxia, both with open and with closed eyes flexion of the fingers and rotation of the hand are noted. The occurrence of this phenomenon is due to muscular dystonia of cerebellar origin.

Differential diagnosis of ataxia

IN clinical practice sometimes it is necessary to make a differential diagnosis between cerebellar ataxia and other types of motor coordination disorders (sensitive, vestibular, frontal, temporal, hysterical ataxia).

Sensitive ataxia observed when deep conductors are damaged, in particular, muscle-articular sensitivity on different levels(peripheral nerves, dorsal roots, posterior cords of the spinal cord, optic thalamus, etc.). Thus, in the absence of vision control, motor centers cease to receive information about the position of the body and limbs in space. An ataxic gait is typical: the patient spreads his legs wide, flexes and straightens them disproportionately, and hits the floor with his heel (“tabetic”, “stamping” gait). In the Romberg test, instability appears only with closed eyes; pseudoathetosis, slow involuntary worm-like movements, may appear in the fingers of outstretched arms with closed eyes. The essence of these excess movements is to try to use as much as possible large quantity proprioceptors and obtain information about the position of the body and limbs in space. With objective neurological examination violations of the muscle-articular, vibration sense, coordination of movements during finger-nose and heel-knee tests, muscle hypotonia are detected.

Vestibular ataxia is caused by damage to the labyrinth, vestibular nuclei or pathways and is static in nature. In the Romberg position, the patient loses balance, deviates or falls in the direction of the lesion. In addition, it is characterized by systemic dizziness, aggravated by sudden head movements or changes in body position, which is accompanied by nausea and vomiting. Decreased hearing and noise in the ear are often observed. Deep sensitivity and cerebellar functions are not affected.

Frontal ataxia occurs in lesions of the fronto-pontocerebellar system and manifests itself on the side opposite to the lesion (crossing of the cortico-pontocerebellar tract). It manifests itself as a miss during the finger-nose test, deviation (fall) of the patient in the opposite direction from the lesion in the Romberg test. Frontal ataxia is combined with other symptoms of damage to the frontal lobe (grasp reflex, “frontal” parkinsonism, etc.). Muscular hypotonia, characteristic of cerebellar lesions, is absent.

temporal ataxia, as a rule, it is a consequence of a tumor of the temporal lobe and is manifested by a group of symptoms (Schwab’s triad): missing the finger-nose test on the side opposite to the lesion (tumor); a tendency to fall backward and in the direction opposite to the tumor; development of hemiparkinsonism on the side opposite the tumor.

Hysterical ataxia It can be either a monosymptom of hysterical neurosis or occur in combination with other symptoms of hysteria. Most characteristic manifestation ataxia – functional gait disorders. These disorders are very diverse and take on bizarre forms with a touch of something artificial, pretentious, and ostentatious. The gait may be spastic, cerebellar, galloping, etc. There is a clear dissociation between the degree of impairment of walking function and the absence of symptoms organic damage nervous system (disorders deep sensitivity, cerebellar symptoms, etc.).

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The cerebellum is a component of the brain that is located in the posterior cranial fossa. Above it rises the medulla oblongata and the pons. The cerebellum is separated from the occipital lobes of the brain by the tentorium, or in other words, by the tent. The tentorium is represented by a process of the dura mater of the brain. The cerebellum can connect to the brain stem - the department that is responsible for all vital functions of the body, such as breathing and heartbeat - thanks to the 3 legs that connect it to the brain stem.

At birth, the mass of the cerebellum is approximately 5% of the total body mass, about 20 g. But with age, the volume of the cerebellum increases, and by 5 months the mass increases 3 times, and by 9 months it is approximately 4 times the original. In humans, by the age of 15, the cerebellum stops increasing in size and weighs approximately 150 g. The cerebellum has a similar structure to the cerebral hemispheres. It is even called the “little brain.” There are two surfaces in it:

Upper;
Bottom.

And also two edges:

Front;
Rear.

The cerebellum has 3 sections:

Ancient – hook;
The old one is the vermis, which is located in the midline of the cerebellum;
New - hemispheres, which are 2 in number, are located on the sides of the worm and imitate hemispheres big brain. In evolutionary terms, this is the most developed structure of the cerebellum. Each hemisphere is divided into 3 lobes by grooves, with each lobe corresponding to a specific section of the worm.

Like the brain, the cerebellum has gray and white matter. Gray makes up the cortex, and white makes up the fibers, with the cerebellar nuclei located inside - globular, dentate, tegmental. These nuclei play an important role in the conduction of nerve pathways that do not cross in their path, or cross twice, which leads to the localization of signs of the disorder on the affected side. Nerve impulse, running through the cerebellar nuclei, is necessary for the cerebellum to perform its functions:

Coordination of movements, their proportionality and smoothness;
Maintaining body balance;
Regulation of muscle tone, its redistribution and maintenance, which ensures adequate performance of the functions assigned to the muscles;
Providing a center of gravity;
Synchronization of movements;
Anti-gravity.

Each of these functions plays a big role in a person’s life. When these functions are lost or impaired, characteristic symptoms appear that unite general term"cerebellar syndrome". This syndrome is characterized by disorders of a vegetative nature, motor sphere, and muscle tone, which cannot but affect the patient’s quality of life. One of components syndrome is ataxia.

Cerebellar ataxia

Ataxia is a disorder of coordination and motor function. This manifests itself in the form of disturbances in movement, gait and balance. Ataxia is accompanied by another group of symptoms specific to it. If they appear in a stationary position, then we're talking about about static ataxia, if during movement, then about dynamic. Ataxia has many forms and occurs in a wide variety of diseases. Separately, there is cerebellar ataxia, which is associated with pathological processes in the cerebellum.

In neurological practice, it is customary to divide cerebellar ataxia into the following types, depending on the nature of the process:

Acute onset;
Subacute onset (from 7 days to several weeks);
Chronic progressive (developing over several months or years) and episodic (paroxysmal).

Cerebellar lesions that lead to the development of ataxia can be either congenital, genetically programmed, or acquired. The main causative factors of this disease are:

Ischemic stroke caused by blockage of an artery with an atherosclerotic plaque, embolus or any other foreign body;
Hemorrhagic stroke;
Trauma as a consequence of traumatic brain injury;
Intracerebral hematoma, which led to compression of intracerebellar structures;
Multiple sclerosis;
Guillain's syndrome;
Inflammatory diseases of the brain – encephalitis;
Obstructive hydrocephalus is dropsy of the brain caused by blockage of brain structures;
Acute intoxications of various origins;
Metabolic disorders.

The occurrence of a subacute form of ataxia is most often associated with an intracerebral tumor - astrocytoma, hemangioblastoma, medulloblastoma ependymoma. Moreover, the tumor is located in the cerebellum, compressing and destroying its structures. But not only tumors cause the subacute form of cerebellar ataxia. The reasons listed above can also cause it to occur.

The chronic form of ataxia is often the result of many years of alcoholism and chronic intoxication - substance abuse or drug addiction. Hereditary forms of ataxia are most often associated with genetic diseases:

Friedreich's ataxia, manifested by disturbances in walking, speech, handwriting, and hearing. The disease is characterized by progressive muscle atrophy involving the optic nerve in the degenerative process, which leads to blindness. Over a long period of time, intelligence decreases and dementia occurs;
Hereditary cerebellar ataxia of Pierre-Marie, which has a high tendency to progression, consists of cerebellar hypoplasia, that is, its underdevelopment. This is manifested by disturbances in gait, speech and facial expressions, involuntary muscle twitches, decreased strength in the limbs, and twitching of the eyeballs. These symptoms are combined with depression and decreased intelligence. The disease usually makes itself felt around the age of 35;
Holmes cerebellar atrophy;
Tardive cerebellar ataxia or cortical cerebellar atrophy of Marie-Foy-Alajouanine;
Olivopontocerebellar degeneration (OPCD).

Cerebellar ataxia and symptoms

The symptoms of ataxia are quite specific. It immediately catches your eye. It is very difficult to miss the occurrence of a disorder. The main characteristic symptoms for cerebellar ataxia are:

Sweeping, uncertain, uncoordinated movements, as a result of which a person may fall;
Unsteady gait that prevents you from walking in a straight line. Moreover, patients are so unsteady on their feet that they prefer to spread their legs wide for greater stability and balance with their hands;
Involuntary stops of motor activity earlier than planned;
Increased motor amplitude;
Inability to stand upright;
Involuntary swaying from side to side;
Intention tremor, which is characterized by the absence of tremors at rest and intense tremor when moving;
Nystagmus, which consists of involuntary twitching of the eyeballs;
Adiadochokinesis, which is manifested by the patient’s inability to quickly perform alternating opposite motor acts. Such people cannot quickly perform the “unscrewing a light bulb” movement. Their hands will not move in concert;
Impaired handwriting, which becomes uneven, sweeping and large;
Dysarthria is a speech disorder in which speech loses its smoothness, slows down, and increased pauses appear between words. Speech is intermittent, chanted - the emphasis is on each syllable;
Muscular hypotonia, that is, weakness with decreased deep reflexes.

In this case, the phenomena of ataxia increase significantly with a sudden change in the direction of movement, with a sudden rise, with a rapid start of movement. Depending on the nature of the manifestation, two types of ataxia are distinguished:

Static, which manifests itself at rest. Patients find it difficult to maintain an upright posture;
Dynamic, which is characterized by signs of disorder during movement.

Diagnostic tests for ataxia

Diagnosis of cerebellar ataxia is not difficult. For the study, functional tests are carried out, which make it possible to separate static ataxia from dynamic one. Static ataxia is more clearly identified with the following tests:

Romberg, in which the patient is asked to stand up straight, eyes closed and arms extended. There is instability and staggering. It is difficult for a person to maintain coordination. If you ask him to stand on one leg, it will be impossible without losing his balance;
Walking along a conventional straight line is impossible. A person will deviate to the right or left, back or forward, but will not be able to walk straight along the line;
Walking with a side step is impossible. Patients seem to dance while performing this movement, and the torso inevitably lags behind the limbs;
“Stars”, which consists of sequentially taking 3 steps in a straight line, followed by 3 steps back along the same line. The test is carried out with open eyes, and then with closed ones;
It is impossible to sit with your arms crossed on your chest when leaving a lying position. Normal cerebellar function ensures synchronous contraction of the trunk muscles, as well as the hamstring muscles. Static ataxia deprives the cerebellum of this ability, as a result of which a person is unable to sit down without helping himself with his hands; he falls back, while at the same time his leg rises. This symptom complex bears the name of the author, Babinsky.

To identify dynamic ataxia, the following tests are used:

Finger-nasal, which is characterized by missing the mark when trying to hit the nose with a finger;
Hitting the hammer is also difficult. The doctor asks the patient to hit the moving hammer with his finger;
Heel-knee, the meaning of which is to suggest that the patient, lying on his back, hit the knee of the opposite leg with his heel and lower the heel with sliding movements to the foot of the other leg. Ataxia does not allow you to hit the knee and lower the heel smoothly evenly;
“Twisting out the light bulb” is a characteristic hand movement that imitates this action. Patients wave their arms unevenly, wildly and roughly;
To check the redundancy and disproportion of movements, ask the patient to extend his arms to a horizontal level, palms forward. The doctor's command to change the position of the palms down will not be successful. A clear 180° turn is simply impossible. In this case, one hand may rotate excessively, while the other lags behind;
Finger Doynikova, which consists in the inability to bend the fingers and rotate the hand from a sitting position, when the hand is relaxed and lies on the knees, palms up;
Finger-digital, in which the patient is asked to close his eyes and is asked to hit with the ends of the index fingers, which are slightly spaced and moved to the sides. Missing and tremor are observed;

An examination by a neurologist reveals decreased muscle tone, nystagmus, dysarthria and tremor. In addition to the doctor's assessment, they use instrumental methods research. They are aimed at identifying changes in the cerebellum, in its structure - tumor nature, post-traumatic hematomas, congenital anomalies or degenerative changes in cerebellar tissue, compression and displacement of adjacent anatomical structures. Among these methods great importance have:

Stabilography;
Vestibulometry;
Electronystagmography;
Computed tomography (CT);
Magnetic resonance imaging (MRI);
Magnetic resonance angiography (MRA);
Dopplerography of cerebral vessels.

Laboratory tests are used to identify infectious brain lesions:

Blood analysis;
PCR research;
Lumbar puncture to examine the cerebrospinal fluid for infection or hemorrhage.

In addition, a DNA study is performed to determine the hereditary nature of ataxia. This diagnostic method allows us to identify the risk of having a baby with this pathology in a family where cases of cerebellar ataxia have been recorded.

Treatment of cerebellar ataxia

Treatment of any disease is aimed, first of all, at eliminating the cause of the disease. If ataxia is not genetic, foundational therapy must be directed against the causative factor, be it a brain tumor, an infectious disease, or a circulatory disorder. Depending on the cause, treatment will vary. However, symptomatic therapy has common features. The main drugs to eliminate signs of the disease include:

Betahistine group drugs (Betaserc, Vestibo, Westinorm);
Nootropic and antioxidants (Piracetam, Phenotropil, Picamilon, Phenibut, Cytoflavin, Cerebrolysin, Actovegin, Mexidol);
Medicines that improve blood circulation (Cavinton, Pentoxifylline, Sermion);
Vitamin B complexes, as well as their complexes (Milgamma, Neurobeks);
Drugs that affect muscle tone (Mydocalm, Baclofen, Sirdalud);
Anticonvulsants (Carbamazepine, Pregabalin).

Thus, in case of infectious-inflammatory genesis of the disease, antibacterial or antiviral therapy is prescribed. For vascular disorders, drugs are prescribed that stabilize blood circulation - angioprotective agents, thrombolytics, antiplatelet agents and vasodilators, as well as anticoagulants. Ataxia, which is caused by intoxication, requires detoxification measures with intensive infusion therapy, diuretics and hemosorbic acid.

For ataxias with a hereditary nature of the lesion, there is no radical treatment. In these cases, metabolic therapy is prescribed:

IN itamins B12, B6 or B1;
Meldonium;
Ginko biloba or piracetam preparations.

Cerebellar ataxia of a tumor nature often requires surgical resolution. Chemotherapy or radiation treatment may be prescribed depending on the type of tumor. Any treatment of ataxia is complemented by physiotherapy and massage. This helps prevent muscle atrophy and contractures. Classes are aimed at improving coordination and gait, as well as maintaining muscle tone.

In addition, a gymnastic complex is prescribed physical therapy, the purpose of which is to reduce incoordination of movements and strengthen the muscle groups of the limbs. Severe clinical symptoms of the disease not only significantly reduce the patient’s quality of life, cerebellar ataxia is fraught with life-threatening consequences. Its complications include:

Frequent repeated infectious processes;
Chronic heart failure;
Respiratory failure.

The prognosis of cerebellar ataxia syndrome depends entirely on the cause of its occurrence. Timely treatment of acute and subacute forms of ataxia caused by vascular pathology, intoxication, inflammation, leads to complete or partial restoration of cerebellar functions. Often, it is not possible to completely cure ataxia. It has a poor prognosis due to the fact that the disease tends to progress.

The disease reduces the patient’s quality of life and causes multiple disorders of other organs and systems. The first warning symptoms require a visit to a doctor. A timely diagnosis and initiation of treatment provide a much higher chance of restoring damaged functions or slowing down the process with a more favorable outcome than in the case of late treatment.

The most severe course is hereditary ataxia. They are characterized by chronic progression with an increase and aggravation of symptoms, which ends in the inevitable disability of the patient. There is no specific prophylaxis against ataxia. The development of the disease can be prevented by preventing injuries, vascular imbalances, intoxications, and infections. And when they appear - timely treatment.

Hereditary pathology can be avoided only through genetic consultation with a specialist about planning the birth of a child. For this purpose they collect maximum amount information about hereditary diseases families. They analyze possible risks and may take samples for DNA testing. All this allows us to preliminary assess the possibility of giving birth to a child with a genetic disease. Planning pregnancy is a prevention for many diseases.

Video

COMPLEMENT(lat. complementum addition) - a polymolecular system of whey proteins, one of the most important factors natural immunity. Functions in the blood of humans, cold-blooded and warm-blooded animals. Contained in lymph and tissue fluids. Being included in the composition of immune complexes, K. carries out the lysis of cellular antigens sensitized by antibodies, determines the immune adhesion reaction (see), participates in the opsonization of bacteria, viruses and corpuscular antigens, accelerating their phagocytosis, and participates in the development of inflammation.

K. was first described under the name “alexin” at the end of the 19th century. as a nonspecific thermolabile factor that determines the bactericidal properties of fresh blood serum (G. Bukhner, 1889). The term “complement” was introduced by P. Ehrlich (1900), who believed that the bactericidal factor complements the cytolytic effect of antibodies.

At least 18 proteins are known that make up the K system. These include 9 K components, 8 of which are individual proteins, and one is a complex: 4 proteins of the properdin system, 1 enzyme inhibitor and 2 inactivator enzymes.

According to the nomenclature adopted by WHO, the K. system is designated by the symbol C, its individual components - by numbers (C1, C2...C9), fragments of the K. components - lowercase letters(e.g. SZA). The presence of enzymatic activity in a fragment is indicated by a line above its symbol, and the presence of a binding center with the cell membrane is indicated by an asterisk near its symbol [K. F. Austen et al., 1968].

K.'s components circulate in the blood in the form of precursors, without combining with free antibodies or antigens. Two biol, mechanisms of activation (binding) of the K. system are described - classical and so-called. alternative, or properdine [Müller-Eberhard (H. J. Muller-Eberhard), 1975; Vogt (W. Vogt), 1974].

The classical mechanism of K. activation is carried out with the participation of IgG and IgM antibodies that are part of immune complexes, or nonspecifically aggregated immunoglobulins of these classes. When combined with antigens or as a result of nonspecific aggregation, centers that bind C1, the first component of the K system, are formed in the molecules of these immunoglobulins (A. Ya. Kulberg, 1975). Fixed on immunoglobulin C1 initiates a chain of reactions into which the remaining components of the K system sequentially enter.

C1 is a complex of three subcomponents (C1q, C1rr and C1s) formed in the presence of calcium ions; C1q is a collagen-like protein with a mol. weighing (mass) 400,000, consisting of six non-covalently linked identical subunits. Each subunit contains a recognition center for binding to an immunoglobulin molecule. The attachment of C1q to immunoglobulin is accompanied by intramolecular rearrangement of C1q and activation of the associated proenzyme Clr, which acts on C1s proesterase. The resulting C1s-esterase (C1s) affects the second (C2) and fourth (C4) components of K in the liquid phase.

The C4 molecule (molecular weight 208,000) is built from three peptide chains - alpha, beta and gamma, connected by disulfide bonds. C1s cleaves off the C4a peptide from the alpha chain, mol. the weight is 8000, and in the remaining C4b fragment of the molecule a binding center appears with the cell membrane sensitized by antibodies. When C1s acts on C2, mol. the weight of which is 117,000, two fragments are formed - C2b (mol. weight 37,000) and C2a (mol. weight 80,000). In the latter, a binding center for C4b is formed. The C42 complex formed on the cell membrane is capable of cleaving C3; therefore it is called S3 convertase.

The SZ molecule (molecular weight 180,000) is built from two peptide chains - alpha and beta. As a result of the cleavage of C3 peptide from the alpha chain by C3 convertase with mol. weighing 9000 in the C3b fragment of the molecule, a binding center with the cell membrane is formed and a C423 complex with peptidase activity towards C5 (C5 convertase) is formed on the membrane.

After proteolytic cleavage of C5, the assembly of the membrane attack unit begins from the so-called. terminal components of the K system. The C5 molecule is constructed similarly to S3 from two peptide chains a and p, mol. whose weight is 110,000 and 70,000, respectively. C5 convertase cleaves off the C5a peptide from the alpha chain with a mol. weighing 16,500. The resulting C5b fragment has the ability to sorb sequentially one molecule of C6 and C7. The C567 complex sorbs one C8 molecule and six C9 molecules. At the moment of formation, the C5-9 complex attacks the cell membrane, causing its destruction. The cytolytic activity of the complex is determined by C8 and is significantly enhanced by C9.

Along with the cytolytic components, when the K system is activated, the physiologically active peptides C3a and C5a, called anaphylatoxins, are formed; they cause the release of histamine by mast cells. contraction of smooth muscles and increase vascular permeability, and also serve as chemotactic factors for polymorphonuclear cells. Directed migration of polymorphonuclear cells at the site of K. activation is also caused by the trimolecular complex C567 [Ward (P. Ward), 1975]. Another biologically active peptide that appears upon activation of the K system is C3b. When linking with cell membrane it acquires a second stable binding center in relation to receptors located on the surface of a number of cells (macrophages, platelets, erythrocytes). This process, called immune adhesion, enhances the phagocytosis of K.-loaded cells and corpuscular particles [S. Ruddy, 1974].

K. also takes part in the mechanism of nonspecific resistance to infections. In this case, the K. system is activated without the participation of antibodies by polysaccharides or lipopolysaccharides that are part of cell walls bacteria, yeast, plants, or aggregated IgA. K. binding occurs along an alternative pathway, starting from C3, bypassing the activation stages of C1, C4 and C2. It has been shown that the serum protein properdin, the C3 convertase activator and a number of its precursors take part in the formation of C3 and C5 convertases of the alternative pathway. When K is activated via the alternative pathway, as well as the classical one, the cytolytic complex C5-9 is formed, as well as the physiologically active peptides C3a and C5a. This mechanism probably underlies the nonspecific elimination of viruses and altered erythrocytes from the body [L. Pillemer, 1954, 1955].

All of the indicated functions of the reaction products of the components of K. are aimed at the destruction and rapid removal of inf. from the body. or foreign agents. They determine the significance of the K system as a protective factor of the body.

In addition to its protective function, the K system can contribute to damage to the body’s own tissues in a number of diseases with an autoimmune component (glomerulonephritis, systemic lupus erythematosus, arteritis, myocarditis, endocarditis). In this case, activation of the K. system is carried out both by antibodies directed against tissues and by soluble or fixed immune complexes in tissues. The resulting complexes C423 and C5-9 of the K components are fixed on both sensitized and non-sensitized cells by antibodies, causing destruction of their membranes. An important role in the autoimmune process also belongs to C3a and C5a peptides and the C567 complex [N. R. Cooper, 1974; L. G. Hunsicker, 1974; McCluskey (R. Mc Cluskey), 1975].

The content of K. is most often judged by its hemolytic activity against sheep erythrocytes sensitized with rabbit hemolysin. K. titer is expressed in 100 or 50% hemolytic units (CH100 or CH50), i.e. minimum quantity K., a cut under the selected standard experimental conditions, lyses, respectively, 100 or 50% of optimally sensitized erythrocytes. K.'s content can also be assessed by its cytolytic effect in the lymphocyte - antilymphocyte serum system [Terasaki (R. I. Terasaki), 1964]. K., which does not have lytic activity, for example. K. horse, bull, mouse, can be determined in the agglutination reaction of sensitized erythrocytes loaded with K. with bovine serum protein - conglutinin (see Conglutination).

Individual components of K. are titrated in a hemolytic test using special reagents, which are preparations of fresh guinea pig serum, devoid of only the titrated component, and containing the remaining components in excess. The corresponding hemolysis intermediates can also be used as titration substrates. Immunochemical and titration methods using anti-sera to pure components of K are widely used.

K content in animal sera various types, according to hemolytic titration, varies greatly. Its highest titer, reaching 200 CH50 per 1 ml, was determined in guinea pigs. 1 ml of human serum contains on average 70, and rabbit 20 CH50 [R. Audran, 1959, 1960]. However, K.'s titers in the hemolytic test do not always correspond to its true content. Thus, K. of some species does not lyse sensitized sheep erythrocytes, although it binds to them. Hemolytic activity K. different types is not the same when tested in different hemolytic systems [Boyd (W. S. Boyd), 1969].

Biol, the properties of K. of various types are largely determined by the content of individual components in them. Species differences are especially pronounced in the content of C2 and C4. These components are completely absent or contained in very low titers in the sera of horses, bulls, and mice, which do not have lytic activity. Serums of all types are characterized by a high content of C1. The content of K. components in human serum is determined in weight units.

Individual fluctuations in the level and composition of blood cells healthy people at the age of 8-35 years are insignificant and do not depend on blood type and Rh factor. Typically, women contain 10% less K than men, and in newborns and pregnant women its content is reduced by an average of 30% [J. Gumbreitier et al., 1960, 1961]. There was a tendency to increase K. levels between the ages of 35 and 60 years.

The content of K. in the sera of patients depends on the nature of the disease. In most acute infections of purulent etiology, as well as in staphylococcal bacteremia in initial period an increase in K titers is observed. It is believed that it is associated with the activation of cells of the reticuloendothelial system, in particular macrophages that synthesize C2, C4, C5. During the period of elimination of antigens with the participation of antibodies, K.'s titers decrease and reach the norm during recovery. In a number of diseases that affect liver parenchyma cells, for example, cirrhosis, hepatitis, hron, cholecystitis, the synthesis of C3-, C6-, C9- and C1-inhibitor is disrupted, which leads to a decrease general level K. As a rule, the level of K. decreases in allergic conditions, autoimmune diseases and diseases of immune complexes due to the binding of K. circulating in the blood and bound in tissues by immune complexes. Cases of deficiency in individual components of K., accompanied by various pathol, conditions are described.

The K. system is active in the body and in freshly isolated serums. K. is inactivated within 2-4 days when sera are stored in the refrigerator (t° 5°), and as a result of heating the sera at t° 56° - for 20 minutes. Inactivation of K. under the influence of various physical agents has been described. factors - sunlight, ultraviolet radiation, shaking, under the influence of chemicals. agents - weak solutions of acids, alkalis, organic solvents, proteolytic enzymes (L. S. Reznikova, 1967). Activity K. long time preserved in freeze-dried serums, when sodium sulfate (5%) and boric acid (4%) are added to fresh serums, in serums stored at a temperature of -40° and below.

K.'s ability to be included in immune complexes is used to detect antibodies and antigens (see Antigen - antibody reaction, Complement fixation reaction). However, it must be borne in mind that many antisera and some antigens bind K. nonspecifically. This phenomenon, called the anticomplementary effect, is expressed in a decrease in the hemolytic activity of K. It may be due to the admixture of aggregated globulins, lipopolysaccharides or proteolytic enzymes in titrated preparations, as well as bacterial contamination of the preparations (Boyd, 1969). The increased ability of antibodies of some individuals within one species to nonspecific fixation of K. is called deviability, and antibodies that have this property are called deviable.

Study of the activation process of K., clarification of biol, properties of activation products of K. components, level of K. in normal conditions and with various diseases allows us to understand its protective function and its role in tissue damage. This knowledge is necessary, in particular, for the development of scientifically based methods for the prevention and treatment of diseases caused by activation of the K system.

Determination of K. titers in various diseases over time has practical significance, since it is an indicator of immunol, the state of the body, the effectiveness of treatment. activities and has prognostic significance.

Bibliography: Boyd W. Fundamentals of immunology, trans. from English, p. 346, M., 1969; Inflammation, immunity and hypersensitivity, ed. G. 3. Moveta, lane. from English, p. 422, M., 1975, bibliogr.; Kulberg A. Ya. Immunoglobulins as biological regulators, p. 106, M., 1975, bibliogr.; CabotE. iMeyer M, Experimental immunochemistry, trans. from English, p. 140, M., 1968, bibliogr.; P e z n and to the island and L. S. Complement and its significance in immunological reactions, M., 1967, bibliogr.; A u s t e n K. F. a. o. Nomenclature of complement, Bull. Wld Hlth Org., v. 39, p. 935, 1968; Col ten H. R. Biosynthesis of complement, Advanc. Immunol., v. 22, p. 67, 1976, bibliogr.; Comprehensive immunology, ed. by N. K. Day a. R. A. Good, v. 2, N.Y., 1977; Muller-Eberhard H. J. Complement, Ann Rev. Biochem., v. 44, p. 697, 1975, bibliogr.; Yogt W. Activation, activities and pharmacologically active products of complement, Pharmacol. Rev., v. 26, p. 125, 1974, bibliogr.

I. A. Tarkhanova.

Complement is a complex set of proteins that act together to remove extracellular forms of a pathogen; the system is activated spontaneously by certain pathogens or by the antigen:antibody complex. Activated proteins either directly destroy the pathogen (killer effect) or ensure their better absorption by phagocytes (opsonizing effect); or perform the function of chemotactic factors, attracting inflammatory cells to the zone of pathogen penetration.

The complement protein complex forms cascade systems found in blood plasma. These systems are characterized by the formation of a fast, multiply amplified response to the primary signal due to a cascade process. In this case, the product of one reaction serves as a catalyst for the next one, which ultimately leads to lysis of the cell or microorganism.

There are two main pathways (mechanisms) for complement activation - classical and alternative.

The classical pathway of complement activation is initiated by the interaction of the complement component C1q with immune complexes (antibodies associated with bacterial cell surface antigens); as a result of the subsequent development of a cascade of reactions, proteins with cytolytic (killer) activity, opsonins, and chemoattractants are formed. This mechanism connects acquired immunity (antibodies) with innate immunity (complement).

The alternative pathway of complement activation is initiated by the interaction of the complement component C3b with the surface of the bacterial cell; activation occurs without the participation of antibodies. This pathway of complement activation belongs to the factors of innate immunity.

In general, the complement system refers to the main systems of innate immunity, the function of which is to distinguish “self” from “non-self”. This differentiation in the complement system is carried out due to the presence on the body’s own cells of regulatory molecules that suppress the activation of complement.

Summary. Complement [lat. complementum- addition]:

1) in immunology, a group of proteins (usually from 9 to 20) normally present in the blood serum of vertebrates, which are activated as a result of the body’s immune response under the influence of both antibodies belonging to the immunoglobulins of the IgG and IgM classes, and bacterial liposaccharides or other compounds; protein complex of blood serum, one of the components of innate immunity. Complement takes part in the regulation of inflammatory processes, activation of phagocytosis and lytic action on cell membranes, and is activated by interaction with immune complex. The sa system is considered, along with macrophages, as the front line of the body's immune defense. During complement activation, a cascade of sequential reactions of specific limited enzymatic proteolysis occurs, in which the complement components are inactive. transform into an active state as a result of the cleavage of peptide fragments. The latter have various physiological activities and can be anaphylatoxins (cause contractions of smooth muscles, increase vascular permeability, etc.), chemotaxis factors (provide directional movement of cells) and leukocytosis, mediators of immune response reactions, participate in the activation of macrophages and lymphocytes, in the regulation of antibody production , and also perform some other functions. Fragments of activated complement components also control the biosynthesis and release of interleukins, prostaglandins and leukotrienes. Complement causes disturbances in immune reactions (can cause autoimmune diseases) and the release of histamine in immediate allergic reactions. The term “complement” was introduced by P. Ehrlich and J. Morgenroth in 1900;

2) in genetics, a group of chromosomes produced from a specific nucleus of a gamete or zygote and consisting of one, two or more chromosome sets (H. Darlington, 1932).