Treatment of the akinetic-rigid form of the disease. Rigid form of Parkinson's. Parkinson's disease: types, clinical manifestations

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A rare neurological disease of unknown origin, manifested by constant tonic muscle tension (rigidity) and isolated painful spasms that limit the patient’s mobility. The “rigid person” syndrome is diagnosed based on the typical clinical picture and electrophysiological studies, with the exclusion of other pathologies that can cause rigidity. Treatment is symptomatic. Benzodiazepines and baclofen are traditionally used. Alternative methods are plasmapheresis, glucocorticosteroid therapy, intramuscular injection of botulinum toxin, and immunoglobulin treatment.

General information

Rigid person syndrome (RPS) is a rare neurological pathology clinically manifested by muscle rigidity and spasms. Muscle rigidity is their constant tonic tension. The consequence of rigidity is stiffness and limitation of voluntary and involuntary motor acts. In rigid person syndrome, rigidity predominates in the axial (running along the spine) muscles and proximal muscles of the limbs. At the same time, the tone of the extensor muscles is higher than that of the flexors, which gives the patient a characteristic appearance with an unusually straight and even arched back, a pronounced lumbar deflection, shoulders turned back and a slightly thrown back head. The “rigid person” syndrome was first described in detail in 1956 by American neurologists Mersch and Woltman, after whom it is called Mersch-Woltman syndrome. Statistics on the prevalence of the syndrome have not yet been collected due to its great rarity.

Causes of “rigid person” syndrome

Much remains unclear in the etiopathogenesis of the syndrome. Clinical studies conducted by specialists in the field of neurology have shown that the basic pathogenetic substrate of pathology is the increased excitability of motor neurons localized in the anterior horns of the spinal cord. Presumably, this is due to dysfunction of the GABAergic system, which has an inhibitory effect on the motor neurons of the central nervous system. This hypothesis is confirmed by the low content of GABA in the cerebrospinal fluid of patients with SRS and the antispastic effectiveness of GABAergic and antiadrenergic pharmaceuticals observed in them.

In 1966, the autoimmune theory of the etiology of the syndrome was outlined. In 1988, in patients with rigid person syndrome, antibodies to glutamate decarboxylase, an enzyme that catalyzes the synthesis of GABA from glutamic acid and is concentrated in the endings of GABAergic neurons, were found in the cerebrospinal fluid and in the blood. However, further studies showed that such antibodies are present in the cerebrospinal fluid in only 68% of patients with HRF, and in the blood - in only 60%. It should be noted that the clinical picture is identical in patients with and without antibodies.

The question of the pathogenetic role of the identified antibodies to gutamate decarboxylase remains unclear: whether they are the direct cause of motor neuron dysfunction or only its consequence. Along with these antibodies, the “rigid person” syndrome is often accompanied by the presence of other antibodies: to thyroid cells, gastric epithelium, insulin-producing cells of the pancreas, antimitochondrial and antinuclear antibodies.

Symptoms of “rigid person” syndrome

The disease can debut at any age, but most often manifestation occurs in the third and fourth decades of life. Typically gradual development. As a rule, the first symptoms are transient tension (rigidity) and pain in the muscles of the back, neck and abdomen. Then the rigidity becomes permanent, accompanied by periodic intense muscle spasms. Over the course of several months, the muscles of the proximal arms and legs are involved in the process. In 25% of patients, spasms of the facial muscles are observed, leading to hypomimia or involuntary movements (for example, stretching of the lips during a spasm of the orbicularis oris muscle); damage to the distal muscles (usually the muscles of the legs).

The predominance of rigidity in the extensor muscles leads to hyperextension of the back, the formation of pronounced lumbar lordosis, a constant raised position of the shoulders and some tilting of the head. Due to the tonic state of the abdominal muscles, a “board-shaped stomach” is formed. The gait of a “wind-up doll” is characteristic, with slow, difficult small steps. In severe cases, patients’ mobility is severely affected: they cannot sit on or get up from a chair, get dressed, bend over, or turn their head. In this case, the limbs seem tightly fused with the body and move with it as a single block. If the “rigid person” syndrome is accompanied by damage to the respiratory muscles, then patients experience respiratory failure even with minor physical exertion.

Against the background of permanent rigidity, isolated muscle spasms are observed. They can be spontaneous, actional or reflexive in nature. Actional spasms are provoked by movement, reflex spasms are provoked by variable external influences (touch, cold, straining, emotional reaction, etc.). Most often, spastic contractions occur in the muscles of the back and legs. The duration of spasms varies from several seconds to tens of minutes. In some cases, the force of muscle contraction during spasm can be so great that it leads to dislocation or fracture. With spasm of the respiratory muscles and muscles of the larynx, breathing rhythm disorders occur. The generalized nature of the spasm causes the patient to fall. Often spasms occur with acute pain, which after the end of the spasm acquires a dull, cerebral character. In 75%, spasms are combined with emotional (anxiety, dysphoria) and autonomic (tachycardia, hyperhidrosis, mydriasis, increased blood pressure) symptoms.

The intensity of stiffness and muscle spasms varies throughout the day. Typically they disappear during sleep. In some cases, a spastic status (frequent intense spasms) is observed, threatening the development of severe arrhythmia, heart failure, severe respiratory distress, disseminated intravascular coagulation syndrome, and shock.

Diagnosis of “rigid person” syndrome

Difficulties in diagnosing RFS are associated with its rare occurrence and the need to exclude all other possible causes of rigidity. During the examination, the neurologist draws attention to the absence of any neurological symptoms, except muscle rigidity and increased tendon reflexes. The “rigid person” syndrome should be differentiated from syringomyelia, spinal stroke, spinal cord tumor, myelitis, torsion dystonia, myotonia, and Parkinson’s disease.

The main paraclinical diagnostic method is EPI of the neuromuscular system. Electroneurography does not reveal disturbances in the conduction of impulses along the nerve trunks. Electromyography detects persistent muscle motor unit activity that persists when the patient attempts to relax a muscle or tenses antagonistic muscles. In this case, the shape of action potentials is not changed. Exposure to external stimuli (electrical stimulation, noise, touch) leads to increased EMG activity and provokes simultaneous contraction of antagonist muscles. Characteristic is the disappearance of muscle rigidity with the administration of diazepam or muscle relaxants, or peripheral nerve blockade.

Treatment and prognosis of “rigid person” syndrome

The therapy is aimed at relieving spasms and rigidity. A good effect is achieved with the use of benzodiazepines (diazepam, clonazepam). Treatment starts with a minimum dose, taken 1-2 times a day. Then the dosage is increased, dividing the daily dose into 3-4 doses. When the effect is achieved in the form of the absence of spasms and a decrease in rigidity, the dose of the drug is no longer increased. It is typical for patients to tolerate high doses of benzodiazepines well. However, in a number of patients it is not possible to achieve an effective therapeutic dose due to the strong sedative effect of the drugs. In such cases, baclofen is prescribed, a GABA receptor agonist. It can be prescribed in combination with benzodiazepines, which allows achieving a therapeutic effect at lower dosages of drugs. In severe cases, intrathecal infusion of baclofen is performed using an implanted pump.

In cases of ineffectiveness or intolerance of the above treatment, valproate, tiagabine, vigabatrin become the drugs of choice. It is possible to inject botulinum toxin into the paravertebral muscles. Correction of concomitant pathologies (hypothyroidism, diabetes mellitus, etc.) helps reduce rigidity. Based on the autoimmune etiopathogenetic hypothesis of HRF, immunotherapeutic treatments have been developed. However, their effectiveness varies between patients. The combination of glucocorticosteroids and intravenous immunoglobulin have proven themselves to be effective. The ineffectiveness of all of these treatment methods is an indication for the prescription of cytostatic therapy.

Rigid person syndrome has a serious prognosis. Characterized by slow progression. In some patients, it is possible to stabilize their condition and maintain the ability to self-care through symptomatic therapy; in others, rigidity progresses and, despite the treatment, after several years it makes them bed sick. Immobility leads to congestive pneumonia, which in most cases causes death. In some patients, the cause of death is severe autonomic disorders or diabetic coma.

Akine tiko-rigi bottom syndrome(Greek akinē tos immobile; lat. rigidus rigid. hard; synonym: amyostatic symptom complex, hypokinetic-hypertensive symptom complex) - movement disorders, expressed by a decrease in motor activity, a slowdown in voluntary movements and an increase in muscle tone of the plastic type. A.-r. With. observed with shaking paralysis, after encephalitis (epidemic lethargic, Japanese, St. Louis encephalitis), as a result of cerebral atherosclerosis, toxic effects, for example, poisoning with manganese, carbon monoxide, as a side effect during treatment with phenothiazine drugs, rauwolfia, methyldopa and others, with hepato-cerebral dystrophy, after traumatic brain injury, etc.

Akinetic-rigid syndrome is a consequence of damage to the extrapyramidal system and primarily the substantia nigra and basal ganglia (nigral syndrome). In its development, a hereditary inferiority of enzymatic mechanisms for controlling catecholamine metabolism in the brain, manifested by a decrease in the concentration of dopamine in the basal ganglia and substantia nigra, plays a certain role. Genetically determined inferiority of subcortical structures can manifest itself under the influence of various external factors.

Slowness of voluntary movements (bradykinesia) with A.-r. With. reaches various degrees, up to the inability to move (akinesia); There is a decrease in motor activity (hypokinesia), a plastic increase in muscle tone (rigidity), the disappearance of friendly movements (syncinesia), such as hand movements when walking, small friendly movements that give an individual characteristic to voluntary movements, gestures, facial expressions (amimia). The speech of patients becomes monotonous and slurred. As a result of an increase in muscle tone, a peculiar posture of the patient develops. Many patients exhibit rhythmic tremor, which has a low frequency and stops with purposeful movements (see Parkinsonism). When muscle tone increases to the point of rigidity (akinetic-rigid Förster syndrome), the patient loses the ability to move. With passive movements, the limb can remain in its assigned position for a long time, and Westphal's paradoxical phenomena arise.

The diagnosis is made on the basis of clinical data, however, a detailed clinical picture is not observed in all patients with A.-r. With. Thus, during the treatment of neuropsychiatric diseases with phenothiazine drugs and after surgical treatment of parkinsonism, hypokinesia and stiffness may occur without an increase in muscle tone of the extrapyramidal type.

Treatment is aimed at the underlying disease. Along with this, drugs that reduce muscle tone (muscle relaxants) and antiparkinsonian drugs are used. If conservative treatment is unsuccessful, stereotactic neurosurgical operations are performed in some cases. To resolve the issue of neurosurgical treatment, the patient should be sent to a specialized hospital.

The prognosis is determined by the underlying disease. With A.-r. pp., caused by intoxication and side effects of drugs, the elimination of these factors can lead to the disappearance of the disorders characteristic of this syndrome.

Bibliography: Arushanyan E.B. About neuroleptic parkinsonism and tardive dyskinesia and methods of pharmacological correction of these pathological conditions, Zhurn. neuropath. and psychiat., t. 85, no. 2, p. 268, 1985, bibliogr.; Diseases of the nervous system, ed. P.V.Melnichuk, vol. 2, p. 105, M., 1982; Kamenetsky V.K. Treatment of patients with vascular parkinsonism with drugs Nak and Madopar. Wedge. med., t. 62, no. 4, p. 112, 1984, bibliogr.; Kurako Yu.L. and Volyansky V.E. New directions in modern pharmacotherapy of parkinsonism, Zhurn. neuropath. and psychiat., vol. 84, no. 9, p. 1401, 1984, bibliogr.; Petelin L.S. Extrapyramidal hyperkinesis, M.. 1983.

5.1. CONCEPT OF THE EXTRAPYRAMIDAL SYSTEM

Movement is provided by striated muscles. Their condition is affected peripheral motor neurons, whose function is determined by the total impact of diverse impulses on them. For a long time, when studying movements, the influence on them was first recognized mainly by large pyramidal cells (Betz cells), included in the V layer of the motor zone of the cortex of the anterior central gyrus (mainly area 4, according to Brodmann). It was believed that connections between central (cortical) and peripheral motor neurons, which are now sometimes called upper and lower motor neurons, respectively, can only be monosynaptic, since they are carried out only through the axons of Betz cells. The efferent pathways connecting these neurons are usually called pyramidal, due to the fact that they participate in the formation of the pyramids located on the ventral surface of the medulla oblongata.

When the presence of the pyramidal system had already become generally accepted, researchers drew attention to the fact that many other cellular structures located at different levels of the central nervous system also take part in providing motor functions, which began to be called extrapyramidal(the term was introduced in 1908 by the English neurologist S. Wilson (Wilson S., 1878-1937).

It was later found that most connections between central and peripheral motor neurons are polysynaptic, since they also include cells that are located in various extrapyramidal structures located in the subcortical regions of the cerebral hemispheres and in the brain stem.

At the suggestion of R. Granit (Granit R., 1973), the structures of the so-called pyramidal paths, on which the active movements of the body and its parts mainly depend, were called phasic. Extrapyramidal structures that influence motor acts, position, maintaining body balance and posture were named by R. Granit tonic.

Phasic and tonic structures are in a relationship of mutual reciprocal control. They form a unified system for the regulation of movements and posture, consisting of phasic and tonic subsystems. At all levels of these subsystems, from the cortex to the motor neurons of the spinal cord, there are collateral connections between them.

The tonic and phasic subsystems are not only complementary, but also, in a certain sense, mutually exclusive. Thus, the tonic system, ensuring the preservation of posture, fixes the body position by tensioning the “slow” muscle fibers, and also prevents possible movements that could lead to a movement of the center of gravity and, consequently, a change in posture. On the other hand, to carry out fast movement, it is necessary not only to turn on the phasic system, leading to the contraction of certain muscles, but also to reduce the tonic tension of antagonist muscles, which makes it possible to perform a fast and accurate motor act. In this regard, the static state, physical inactivity, is characterized by hyperactivity of the tonic system and excessive collateral inhibition of the phasic system. At the same time, pathological syndromes characterized by rapid phasic, excessive, involuntary movements (chorea, hemiballismus, etc.) are usually combined with atony.

The accepted division of the nervous structures that provide motor acts into pyramidal and extrapyramidal is not indisputable, and their names were given by chance. The pathway, called the pyramidal tract, was identified at the spinal level and designated by this term by P. Flexig in 1885. Subsequently, the idea of ​​a two-neuron pyramidal system, which is a corticospinal tract, was created.

In 1908, the English neurologist S. Wilson (Wilson S., 1878-1937), in the process of studying the disease now known as hepatolenticular degeneration, or Wilson-Konovalov disease, noted that the state of motor functions is also influenced by the subcortical nodes, not included in the concept of a pyramid system. Since then, all the structures of the brain, which, as it turned out later, influence the state of the striated muscles and, therefore, are involved in providing movements, began to be called extrapyramidal. However, today it is known that from the point of view of the study of phylogenesis and ontogenesis of the nervous system, extrapyramidal structures are formed earlier than pyramidal ones. Extrapyramidal structures in the motor system can be considered as basic, while the classically recognized monosynaptic pyramidal fibers (Betz cell axons) constitute only 2-2.5% in human corticospinal pathways. They can be considered as a kind of superstructure over the extrapyramidal pathways, which arises in primates with the need to perform subtle and precise motor acts. In humans, this need has reached its highest level due to the improvement of voluntary movements of the arms, mainly the hand and fingers, as well as subtle movements carried out through the facial muscles and speech motor apparatus, or, in the words of V.M. Bekhterev, “special” movements.

In 1973, the leading American physiologist P. Milner spoke about this as follows: “ The very division of the motor system into pyramidal and extrapyramidal is a source of confusion and error. Perhaps it was the result of a historical misconception that arose from the initial idea that the pyramidal system was the only motor system. Therefore, those parts of the brain whose participation in motor functions were discovered later were united under the name of the extrapyramidal system. It is difficult to draw a clear functional line between

Figure 5.1.Frontal section of the brain at the level of the mastoid bodies. 1 - interhemispheric longitudinal fissure; 2 - vault; 3 - corpus callosum; 4 - choroid plexus of the lateral ventricle; 5 - radiance of the corpus callosum; 6 - medial nucleus of the thalamus; 7 - tail of the caudate nucleus; 8 - hippocampus; 9 - subthalamic nucleus; 10 - III ventricle; 11 - mastoid bodies; 12 - base of the cerebral peduncle; 13 - amygdala; 14 - optic tract; 15 - lower horn of the lateral ventricle; 16 - superior temporal sulcus; 17 - fence; 18 - island; 19 - lateral groove, 20 - tire; 21 - shell; 22 - globus pallidus; 23 - internal capsule; 24 - lateral nuclei of the thalamus; 25 - caudate nucleus; 26 - medullary plate of the thalamus; 27 - anterior nuclei of the thalamus.

these systems. They are not isolated anatomically, with the exception of a short part of the path through the medulla oblongata.”

The opinion expressed by P. Milner is quite logical, but so far, according to tradition, most neurophysiologists and clinicians recognize the advisability of distinguishing the pyramidal and extrapyramidal systems. The extrapyramidal system usually includes numerous cellular formations located in the cerebral hemispheres, in the diencephalon and in the brain stem, as well as afferent and efferent connections between these formations

(Fig. 5.1, 5.2).

The main part of the extrapyramidal system is considered to be the subcortical ganglia or basal ganglia, located deep in the cerebral hemispheres. First of all, these are paired formations such as the lentiform nucleus (nucleus lentiformis) and the caudate nucleus (nucleus caudatus), as well as the amygdala (corpus amygdaloideum).

Figure 5.2.Horizontal section of the brain at the level of the corpus callosum. 1 - genu corpus callosum; 2 - vault; 3 - outer capsule; 4 - outermost capsule; 5 - fence; 6 - lenticular core; 7 - III ventricle; 8 - internal capsule; 9 - choroid plexus of the lateral ventricle; 10 - posterior thalamic radiation; 11 - calcarine groove; 12 - longitudinal interhemispheric fissure; 13 - splenium of the corpus callosum; 14 - posterior horn of the lateral ventricle; 15 - lateral nuclei of the thalamus; 16 - medial nuclei of the thalamus; 17 - anterior nuclei of the thalamus; 18 - island; 19 - internal capsule

In addition, the extrapyramidal system includes the Lewis subthalamic nucleus (nucleus subthalamicus), located in the diencephalon; substantia nigra et nucleus ruber, located in the midbrain; vestibular nuclei and inferior olive (nucleus vestibularis et oliva inferior) - formations of the medulla oblongata; as well as the reticular formation of the brainstem, the cerebellum and areas of the mainly mediobasal sections of the cerebral cortex, which have connections with the listed brain formations.

5.2. STRUCTURES AND BASIC FUNCTIONS OF THE EXTRAPYRAMIDAL SYSTEM

Lenticular nucleus - the largest nuclear formation located in the depths of the cerebral hemisphere, consists of three segments formed from gray matter. Two of them (medial), lighter, make up the so-called pale ball (globus pallidus). The globus pallidus consists of large cells located in loops, which are formed by myelin fibers, which are found here in large numbers and cause its “pallor.” The laterally located segment of the lentiform nucleus is called shell (putamen). Shell and nearby caudate nucleus consist of a large number of small cells with short branching processes and large multipolar neurons between them with long axons.

The similarity of phylo- and ontogenesis, histological structure and biochemical composition, as well as a certain commonality of functions serve as the basis for combining the putamen and caudate nucleus into the striatum (corpus striatum seu neostriatum), or striatal system. The striation of the striatum is due to the presence of alternating sections of gray and white matter in it. The striatal system is opposed to the pallidal system, which is also known as paleostriatum since it is more ancient in phylogenetic terms and is formed earlier in the process of ontogenesis.

The striatal and pallidal systems have different origins, different structures and, to some extent, opposite functions. The putamen and caudate nucleus originate from paraventricular structures located near the lateral ventricle, while the globus pallidus, located near the third ventricle, has a common origin with the subthalamic nucleus. In the pallidal and striatal systems, the presence of elements of somatotopic representation is assumed.

The caudate nucleus follows the contours of the lateral ventricle and has the shape of an ellipse, with its tail almost reaching the amygdala nucleus. The putamen is located outside the globus pallidus and is separated from it by a layer of myelinated fibers - the lateral medullary plate of the globus pallidus. The lateral side of the shell is delimited from the enclosure by the outer capsule (capsula externa). It consists of associative fibers connecting the auditory area of ​​the temporal lobe cortex with the motor and premotor cortex.

Pallidal and striatal structures unite concept striopallidal system. This unification is due to the fact that during the normal functioning of the body, their functions mutually balance each other, and thanks to this, the striopallidal system influences motor acts as a single whole. Moreover, in this unified functional system, pallidal structures are usually recognized as activating, and striatal structures as inhibitory. The striopallidal system is an integral part of the extrapyramidal system, a broader concept that includes a number of other brain structures.

The structures of the striopallidal system have connections with each other, as well as afferent and efferent connections with other parts of the extrapyramidal system, in particular with the substantia nigra, red nucleus, reticular formation, cerebellum, as well as with the cerebral cortex and peripheral motor neurons of the brainstem and spinal cord. Through the anterior commissure

The brain (Meynert's commissure) interacts with the subcortical nodes of the right and left hemispheres. The close connection of the striopallidal system with the nuclei of the hypothalamic part of the brain determines its role in the mechanisms of emotional reactions.

The striatum receives impulses from many parts of the cerebral cortex, and its ipsilateral connections with motor areas (postfrontal areas, precentral gyrus, paracentral lobule) are especially significant. The nerve fibers that provide these connections are arranged in a certain order. The impulses arriving through them have a mainly inhibitory effect on the cells of the striatum. Another system of afferent fibers ensures the transmission of impulses to the striatum from the centromedian nucleus of the thalamus. These impulses most likely have an activating effect on the own cells of the striatum.

Afferent pathways from the caudate nucleus and from the putamen, which make up the striatum, are directed to the lateral and medial segments of the globus pallidus, separated by a thin medullary plate. Besides, the striatum has direct and inverse connections with the substantia nigra, which is provided by the axons of strionigral and nigrostriatal neurons, respectively. Nigrostriatal neurons are dopaminergic, inhibiting the function of striatal cholinergic neurons and thus reducing their inhibitory effect on the structures of the pallidum. GABAergic strionigral neurons inhibit the activity of cells in the substantia nigra. They have an inhibitory effect on both dopaminergic nigrostriatal neurons and nigrospinal neurons, the axons of which are directed to gamma motor neurons of the spinal cord, thus regulating the tone of striated muscles. Some of the nerve fibers coming from the striatum ensure its influence on many nuclear formations related to the extrapyramidal and limbic-reticular systems.

The efferent fibers emanating from the medial sector of the globus pallidus comprise, in particular, the so-called lentil loop (ansa lenticularis). Its fibers run ventromedially around the posterior limb of the internal capsule to the thalamus, hypothalamus and subthalamic nucleus. After crossing, these pathways, carrying impulses from the pallidal system, are sent to the reticular formation of the trunk, from where a chain of neurons begins that form the reticulospinal tract, ending at the motor neurons of the anterior horns of the spinal cord.

The bulk of the fibers emanating from the globus pallidus are part of the thalamic bundle (fasciculus thalamicus), consisting of pallidothalamic and thalamopallidal fibers, providing direct and feedback connections between the pallidum and the thalamus. The neural connections between the right and left thalami and the cerebral cortex are also reciprocal. The existence of thalamocortical and corticostriatal connections ensures the formation of reverberant circles through which nerve impulses can propagate in both directions, ensuring coordination of the functions of the thalamus, cortex and striatum. The impulse directed to the cortex from the thalamus and striatal system, in all likelihood, affects the degree of activity of the motor areas of the cerebral cortex. Regulation of motor activity, adequacy of tempo, amplitude and coordination of movements are also ensured by connections of the subcortical nodes with the vestibular, cerebellar and proprioceptive systems.

The cerebral cortex influences the functional state of the striopallidal system. The influence of the cortex on extrapyramidal structures is carried out through efferent, descending pathways. Most of them pass through the inner capsule, a smaller part through the outer capsule. It follows that damage to the internal capsule usually interrupts not only the pyramidal tracts and corticonuclear connections, but also leads to a change in the functional state of extrapyramidal formations, in particular causes a pronounced increase in muscle tone in the contralateral part of the body, which is characteristic in such cases.

The activity of the complexly organized extrapyramidal system, as well as the nerve bundles that make up the corticospinal tract, is ultimately aimed at ensuring individual movements and their correction, as well as the formation of complex motor acts. The influence of extrapyramidal structures on motor neurons of the spinal cord is realized by efferent systems. Efferent impulses coming from the formations of the striopallidal system are sent to the cells of the reticular formation, vestibular nuclei, inferior olive and other structures of the extrapyramidal system. Having switched from neuron to neuron in them, nerve impulses are sent to the spinal cord and, passing through the reticulospinal, tectospinal (starting in the quadrigeminal nuclei), rubrospinal tract of Monakov, medial longitudinal fasciculus (starting from the nuclei of Darkshevich and Cajal), vestibulospinal and other extrapyramidal pathways reach the cells of its anterior horns.

Most of the conductors (along the path from the subcortical nodes to the cells of the anterior horns of the spinal cord) cross at different levels of the brain stem. Thus, the subcortical nodes of each hemisphere of the brain and other cellular formations of the brain related to the extrapyramidal system (except for the cerebellum) are connected mainly with alpha and gamma motor neurons of the opposite half of the spinal cord. Through pathways related to the extrapyramidal system, as well as through pyramidal polysynaptic pathways, they control and regulate the state of muscle tone and motor activity.

The activity of extrapyramidal structures determines a person’s ability to take an optimal posture for the upcoming action, maintain the necessary reciprocal ratio of agonist and antagonist muscle tone, motor activity, as well as the smoothness and proportionality of motor acts in time and space. The extrapyramidal system ensures overcoming the inertia of rest and inertia of movements, coordination of voluntary and involuntary (automated) and, in particular, locomotor movements, spontaneous facial expressions, and influences the state of vegetative balance.

In cases of dysfunction of one or another structure of the extrapyramidal system, signs of disorganization of the activity of the entire system may appear, which leads to the development of various clinical phenomena: changes in the impulse to move, polar changes in muscle tone, impaired ability to carry out rational, economical, optimal in efficiency as automated, and voluntary motor acts. Such changes, depending on the location and nature of the pathological process that caused them, can vary widely, sometimes manifesting in different cases with diametrically opposite symptoms:

from motor spontaneity to various variants of violent, excessive movements - hyperkinesis.

A lot of valuable information about the essence of the activity of nervous structures related to extrapyramidal structures was brought by the study of mediators that ensure the regulation of their functions.

5.3. CLINICAL MANIFESTATIONS OF LESIONS TO THE STRIOPALLIDAR SYSTEM

5.3.1. General provisions

The complexity of the structure and functions of the striopallidal system, the presence in it of certain elements of somatotopic representation, determines the wide variety of clinical manifestations of its damage. First of all, there are two groups of extrapyramidal syndromes. The basis of one of them is akinetic-rigid syndrome, for the other the leading ones are various variants of hyperkinesis.

Already by 1918 it was recognized that muscle tone and motor activity depend on the state of the subcortical nodes. The origin of akinesia and rigidity was explained by an imbalance between the influence of the pallidal and striatal systems. It was assumed that the predominance of the function of the pallidal system is manifested by involuntary movements (hyperkinesis) against the background of low muscle tone. Attention was drawn to the fact that this form of imbalance is typical for newborns due to the fact that the maturation of the pallidum structures occurs earlier than the striatum (hence the expression: “a newborn is a pallidal creature”). In this regard, newborns have reduced muscle tone and have a tendency to carry out numerous non-purposeful movements. Subsequently, as the structures of the striatum mature, the child’s movements become more and more focused and coordinated.

Disorders of the balance of the pallidal and striatal systems are more pronounced in the case of damage to the striopallidal system. Dysfunction of its striatal region leads to the development of rapid hyperkinesis that occurs against the background of decreased muscle tone (for example, choreic hyperkinesis). If the pallidum is affected and the function of the striatal system becomes dominant, an akinetic-rigid syndrome develops, characteristic, in particular, of parkinsonism. For parkinsonism extrapyramidal akinetic-rigid syndrome, the leading clinical signs are decreased motor activity and rigidity.

Doctors were guided by this hypothesis for a long time.

The third group of extrapyramidal disorders is caused by damage to the cerebellum and its connections, but for didactic reasons it is customary to consider it separately, and for the same reason we devoted Chapter 7 to it.

5.3.2. Akinesia and rigidity

Options for reducing physical activity are: akinesia- lack of movement, bradykinesia- slowness of movements, oligokinesia-

poverty of movements, hypokinesia- lack of physical activity. With these changes in motor functions, inertia of rest and movement also appears, an extension of the latent period between the stimulus and the response to it, a deterioration in the ability to regulate the speed of movement, and a change in the nature and pace of repeated motor acts. All these clinical phenomena “conceal the expressiveness” of movements and actions and are not directly dependent on the severity of the plastic type increase in muscle tone that usually accompanies them (muscle rigidity).

A decrease in motor activity in parkinsonism is associated with a lack of motivation and initiative to move, with difficulty for the patient to begin movement, while overcoming excessive rest inertia. At the same time, muscle strength is preserved, although the achievement of its maximum appears belatedly. As a result, the patient develops motor passivity, slowness, and sometimes he can maintain a fixed position for hours, reminiscent of a patient in a stuporous state in such cases.

Decreased motor activity and increased muscle tension may include: hypomimia- poverty of facial expressions, hypophonia- weakening of sonority and monotony of speech, micrography- small handwriting. Characteristic violation physiological automated, friendly movements - synkinesis(For example, acheirokinesis- lack of friendly hand movements when walking).

The mask-like appearance of the face, combined with general hypokinesia, in which the typical individual characteristics of gait, gestures, facial expressions, typical for each person, and the individual manner of holding and speaking inherent in each person are lost, make patients with akinetic-rigid syndrome characteristic of parkinsonism similar to each other. With severe akinetic-rigid syndrome, only the eyes, or rather the gaze, retain their mobility.

The study of akinesia confirms that the basal ganglia are important in the initiation (launch) of movement and the automated execution of actions in accordance with previously acquired motor skills. Neurochemical studies have established that hypokinesia is a consequence of a dopamine deficiency occurring in the striatal system, caused by insufficient function of nigrostriatal neurons located in the substantia nigra. The cause of this neurological pathology is the development of degenerative processes in the substantia nigra, which was established in 1919 in the laboratory of the clinic of nervous diseases of the Faculty of Medicine of the University of Paris by our compatriot K.N. Tretyakov. As a result, striopallidal cholinergic neurons located in the striatum are disinhibited, which results in excessive inhibition of the pallidal system, which stimulates active motor acts.

In addition, the development of akinesia can also be influenced by damage to the dopaminergic, nigroreticular neurons contained in the substantia nigra, the axons of which are directed to the reticular formation (RF) of the trunk. There, impulses are switched to nerve cells, the axons of which participate in the formation of the reticulospinal tract. A decrease in the intensity of impulses passing along the reticulospinal tract causes inhibition of gamma motor neuron cells, which helps to increase the tone of striated muscles and at the same time leads to the development of muscle

Rice. 5.3.Akinetic-rigid syndrome in parkinsonism.

rigidity. It cannot be ruled out that in the pathogenesis of hypokinesia-akinesia and slow thinking (Akairii), a certain role is played by the inhibition of the functions of the cerebral cortex, which occurs as a result of the suppression of the influence of the activating reticular formation on it, described by G. Magoon and R. Moruzzi (Magoun H., Moruzzi R., 1949).

Rigidity- constant presence of muscles in a state of tonic tension, which is characteristic of both agonist and antagonist muscles, and therefore the plastic nature of the increase in muscle tone is manifested. During passive movements in the patient's limbs, the examiner feels an unchanging, viscous, waxy resistance. The patient himself primarily complains of stiffness.

With akinetic-rigid syndrome in the initial stage of its development, muscle rigidity in Parkinson's disease is usually asymmetrical and can manifest itself in any one part of the body, but later, as the disease progresses, it becomes more widespread and generalized over time.

The patient’s posture changes (Fig. 5.3): the head and torso are tilted forward, with the chin often almost touching the chest, the arms are pressed to the body, bent at the elbow and wrist joints, the fingers are bent at the metacarpophalangeal joints and straightened at the interphalangeal joints, while the thumb is in a state of opposition to the rest. Increased tone in the neck muscles leads to the fact that already at an early stage of the disease, when called, patients tend to turn their entire body or turn their gaze as much as possible, leaving their head motionless.

The main differences between rigidity and spasticity are:

1. Distribution of zones of increased muscle tone: rigidity is manifested in both flexor and extensor muscles, but is more pronounced in the flexors of the trunk, and is also significant in the small muscles of the face, tongue and pharynx. Spasticity is combined with paresis or paralysis and, with hemiparesis, tends to form the Wernicke-Mann position (arm bent, leg extended).

2. Qualitative indicators of hypertonicity: rigidity - constant resistance to passive movements, “plastic” tone, positive “lead tube” symptom (with passive movements, muscle resistance is uniform, as when bending a lead tube). The spastic state of the muscles is characterized by the recoil symptom and the “jackknife” symptom.

3. Rigidity is less associated with increased activity of the arc of segmental reflexes, which is characteristic of spasticity and depends more on the frequency of discharges in motor neurons. In this regard, tendon reflexes during

fluidity does not change, with spasticity it increases; with rigidity, clonus and pathological signs characteristic of spastic paresis do not occur (Babinsky's symptom, etc.).

4. An obligatory manifestation of rigidity is "gear wheel" phenomenon , with spastic paresis this phenomenon does not occur.

With parkinsonism, the severity of hypokinesia and muscle rigidity may depend to a certain extent on the general condition of the patient. At rest, hypokinesia and muscle rigidity are more pronounced; with slow passive movements, some weakening of rigidity is sometimes observed. Hypokinesia and rigidity are largely influenced by the patient’s mental state, especially negative emotions, which sometimes sharply increase muscle tone. At the same time, in the morning, after sleep, the severity of both components of akinetic-rigid syndrome can significantly decrease. This also sometimes manifests itself in some extreme situations (short-term manifestations paradoxical kinesia). A slight decrease in the severity of muscle rigidity is also observed during the patient’s stay in a warm bath or during therapeutic massage. All this allows us to judge that the functional defect in akinesia and rigidity is variable within certain limits; in some cases it can fluctuate in severity: from a state of general immobility to episodes of almost complete restoration of the functional capabilities of the motor sphere.

5.4. DOPAMINERGIC THEORY OF THE DEVELOPMENT OF AKINETIC-RIGID SYNDROME

With the expansion of the possibilities of neurochemical and neurophysiological examination of patients, it was found that in parkinsonism, the concentration of dopamine in the structures of the striatal system is reduced. This circumstance led to a series of studies that determined creation in 1965 of the dopamine theory of the development of parkinsonism by R. Hassler (Hassler R.), which made it possible to interpret it as a syndrome of striatal dopaminergic deficiency. The theory is based on the idea of ​​a series of biochemical reactions (catecholamine series) that provide the formation of catecholamines, which act as mediators: dopamine (DA), norepinephrine (NA) and adrenaline (A).

At the beginning of this biochemical series, in which each preceding element is transformed into the subsequent one with the participation of a specific enzyme, is the amino acid phenylalanine (P). The catecholamine series of biochemical reactions can be presented as follows: F - tyrosine - DOPA (dioxyphenylalanine) - YES - HA - A. Each stage of the given biochemical transformations is carried out with the participation of a specific enzyme. Thus, the conversion of tyrosine to DOPA occurs with the help of the enzyme tyrosine hydroxylase; DOPA is converted to DA thanks to dopadecarboxylase, etc.

It has been established that DA is produced by cells of the substantia nigra. Its degeneration in parkinsonism was discovered in 1919 (Tretyakov K.N.). The axons of these dopaminergic nigrostriatal neurons transmit inhibitory bioelectric potential to the cholinergic cells of the striatum. If

due to damage or death of nigrostriatal neurons, an insufficient amount of the mediator dopamine enters the striatum, the cholinergic neurons of the striatal body become disinhibited and their own inhibitory effect on the cells of the pallidal system becomes excessive. A decrease in the function of the pallidum structures provokes muscle rigidity and affects the suppression of motor activity, manifested by hypokinesia or akinesia.

By the way, the presentation of R. Hassler’s theory also demonstrates examples of phenomena often observed in the central nervous system: 1) phenomenon of heterogeneity of neurons in a single neural circuit (it consists of neurons that differ in the mediators they produce); 2) phenomenon of anatomical and biochemical dissociation (damage to one morphological structure leads to biochemical changes in other brain structures and disruption of their functions).

Thus, normally, DA-ergic neurons of the substantia nigra have an inhibitory effect on cholinergic neurons of the striatum, restraining their inhibitory effect on the pallidum. In the case of damage to the substantia nigra in the subcortical structures, the balance between the content of DA and ACh is disrupted (DA deficiency with a relative excess of ACh), while the striatum is disinhibited and its inhibitory effect on the pallidum becomes excessive, which leads to the development of akinetic-rigid syndrome characteristic of parkinsonism .

The thus disturbed mediator balance between the concentrations of DA and ACh in the extrapyramidal system can be restored by reducing the level of ACh in the striopallidal system or increasing the DA content. This explains the effectiveness of treating parkinsonism with drugs from the group of M-anticholinergics (cyclodol, etc.). At the same time, the possibility of treating parkinsonism by increasing the concentration of DA in brain tissue is also obvious. For this purpose, in clinical practice, dopamine precursor is usually used in the catecholamine series of biochemical reactions - the levorotatory isomer dioxyphenylalanine (L-DOPA drug) and dopamine agonists.

It should be noted that the dopaminergic theory of R. Hassler is undoubtedly of great practical importance, since in most cases it helps to select the optimal treatment regimen for the patient, however, it does not reflect the fullness of the pathogenetic manifestations that determine the variety of variants of the clinical picture of parkinsonism syndrome.

Akinetic-rigid syndrome is a disease that is one of those disorders that, with long-term and active development and progression, cause loss of motor functions of the human body.

Akinetic-rigid syndrome is manifested by a huge number of unpleasant symptoms that cause discomfort in a person’s life. Over time, they can progress, which ultimately causes the development.

In order to eliminate the possibility of making an erroneous diagnosis, specialists must carefully study the manifesting signs of the disease, conduct laboratory and medical tests and studies. Only on their basis will a competent diagnosis be made and effective treatment prescribed.

Factors provoking the development of the syndrome

It is known that akinetic-rigid syndrome can manifest itself as a result of the negative impact of factors from the external environment.

The greatest danger is posed by the following:

This type of disease is quite closely related to the dysfunction of the extra pyramidal system, that is, certain parts of the brain, which in turn are responsible for performing any type of motor actions.

This syndrome is also known as “nigral syndrome”, because the lesion occurs in the basal ganglia and substantia nigra of the human brain.

Genetic predisposition plays an important role. It is for this reason that experts recommend that patients at risk carefully monitor their health and undergo all necessary medical examinations in a timely manner.

Manifesting symptoms

Akinetic-rigid syndrome can manifest itself with various signs. Depending on the nature of the disease, all symptoms may have different intensity of severity and systematic manifestation.

The patient exhibits the following signs of akinetic-rigid syndrome at various stages of its course:

Varieties of the syndrome

Depending on the manifestation and severity of the symptoms of the disease, doctors divide the disease into several forms. These include:

1. Akinetic-rigid form characterized by muscle rigidity and akinesia.
2. Rigid-shaky form also called a mixed type of syndrome. It combines all the signs of muscle dysfunction in both the lower and upper extremities. As studies prove, manifestations of this nature are more often diagnosed in males.
3. Trembling form(shows tremulous hyperkinesis to a greater extent, while muscle weakness is mild in nature). Today, this form of the disease is referred to as Parkinson's disease. In this case, the patient exhibits trembling quite early in the arms, legs, and lower jaw. Sometimes it is difficult for a person to speak without stuttering. Due to the condition of hand shaking, the ability to independently hold any objects and perform physical activities is lost.

To make an accurate diagnosis, it is necessary to draw up a thorough anamnesis and take into account all clinical manifestations of the disease. Unfortunately, this cannot always be done correctly and on time, since signs of the disease may not always appear in the early stages of the syndrome.

Effective treatment

It is very important before starting therapeutic treatment to find out which factor triggered the development of the disease. In the event that the cause of the illness was poisoning with drugs or toxic substances, the first thing you need to do is eliminate the manifestation of the initial symptoms.

If this is done in time, then the likelihood that the syndrome can resolve on its own increases.

Due to the fact that specific signs of the disease do not appear in every case, treatment is strictly individual in nature and approach.

But, in most cases, therapy is carried out based on the use of the following drugs:

1. A group of medications (they help relax all muscle groups and gradually reduce tone in muscle tissue).
2. Purpose antiparkinson's drugs(help to cope with the manifestation of paralysis and decreased motor abilities of the human body).

During the rehabilitation period, a special role in the treatment of akinetic-rigid syndrome is given to physiotherapeutic procedures. They help strengthen and develop damaged muscle groups of the spine, various joints, as well as blood vessels.

In addition to the use of medications, a special place in treatment is occupied by psychological support and assistance to the patient. For this purpose, special classes and individual therapy are conducted. In this case, close relatives of the patient themselves can participate in the process.

If the therapeutic effect on the patient’s body does not bring the desired result, experts recommend stereotactic neurosurgical surgery. During this process, the damaged brain structures are restored.

At the initial manifestations of signs of akinetic-rigid syndrome, you will need to urgently seek medical help. Only timely treatment can guarantee a speedy recovery and restoration of the patient’s strength, which will allow the person to lead his usual lifestyle!