Neuroleptic extrapyramidal syndromes. Neuropsychological syndromes of damage to deep subcortical structures of the brain Diseases of the extrapyramidal system

Extrapyramidal syndromes - an outdated term, but still widely used in Russian-language literature. It is customary to refer to extrapyramidal syndromes characterized by excessive movements or, on the contrary, insufficient motor activity. The first group of syndromes is called hyperkinetic disorders, the second - hypokinetic. Extrapyramidal syndromes develop with organic lesions of the central nervous system that do not affect the corticospinal (pyramidal) pathways. These syndromes are based on dysfunction of the basal ganglia (basal ganglia) and their connections with other parts of the nervous system.

The term "hyperkinetic syndromes" is not an exact synonym for the term "extrapyramidal syndromes", as it has a broader semantic content and reflects excessive movements that can occur with organic damage to any levels of the nervous system (peripheral nerve, spinal cord, brain stem, subcortical nodes and cerebellum, cerebral cortex) and even in the absence of such a lesion (eg, physiological tremor or physiological myoclonus, psychogenic hyperkinesis). The world literature uses the term "movement disorders" (movement disorders), which combines all hyper- and hypokinetic syndromes of central origin, as well as ataxia, stereotypes, startle syndromes, "foreign hand" syndrome, and some others. Hyperkinetic syndromes of extrapyramidal origin are considered below. Hypokinetic movement disorders are described in the relevant sections of the manual.

The main hyperkinetic syndromes are tremor, chorea, ballism, dystonia, myoclonus, tics. Diagnosis of these syndromes is carried out exclusively clinically.

In recognizing any hyperkinetic syndrome, the analysis of the motor pattern of hyperkinesis is of key importance. In addition, each of the above hyperkinesias in its own way impairs complex motor functions such as maintaining posture, speech, writing, and walking.

Clinical diagnosis of any hyperkinesis begins with determining the nature of hyperkinesis, that is, with the process of “recognition” (“recognition”) of a motor phenomenon that is constantly changing in time and space. Each hyperkinesis in the eyes of a doctor is nothing more than a complexly organized motor image, in the recognition of which its elements such as motor pattern, topography (distribution), symmetry / asymmetry, stereotype or its absence, speed and amplitude of movements, connection with arbitrary movements, as well as with posture or with certain actions.

Syndromic diagnosis is only the beginning of diagnostic work. Its next stage is the definition of the disease that caused the development of hyperkinetic syndrome. It is important to take into account the accompanying symptoms, the “syndromic environment”, the analysis of provoking factors and factors that eliminate or reduce the severity of hyperkinesis (sleep, alcohol, etc.), as well as taking into account the characteristics of the course of the disease and the clinical picture as a whole.

In the treatment of extrapyramidal disorders (with the exception of hyperkinetic disorders) caused by the use of neuroleptics, anticholinergic drugs are mainly used, which have a central N-anticholinergic and moderate peripheral M-anticholinergic effect: cyclodol, akineton, tremblex, etc. Due to the fact that the development of hyperkinetic syndrome is associated with hypersensitivity of dopamine receptors, the appointment of anticholinergics is ineffective. The exception is those cases when hyperkinetic disorders are combined with the phenomena of parkinsonism - an amyostatic symptom complex with a plastic increase in muscle tone. In the treatment of chronic hyperkinesis and dyskinesias caused by taking antipsychotics, it is recommended to use the following drugs in small doses - leponex 25-100 mg / day, sonapax 50-160 mg / day and especially tiapride 200-400 mg / day, as well as valproic acid 400- 600 mg/day, baclofen 15-30 mg/day. Adrenoblockers - anaprilin 30-60 mg / day, as well as bromocriptine 7.5 mg / day and dinezin 150-300 mg / day are prescribed for tremor. Benzodiazepines - diazepam 10-30 mg/day, phenazepam 1.5-3 mg/day, clonazepam 2-6 mg/day, meprabomate 600-1200 mg/day, diphenhydramine 100-200 mg/day are recommended for akathisia and tasikinesia.

Paroxysmal extrapyramidal syndrome or early dyskinesias

Occur in the first 10 days of treatment with the use of small doses of antipsychotics and are characterized by the sudden appearance of motor disorders of a spastic tetanoform nature. Motor disorders can be local and occur in typical areas, affecting an isolated group of muscles, or generalized, accompanied by general motor excitation with affects of fear, anxiety, narrowing of consciousness and autonomic disorders (profuse sweat, hypersalivation, lacrimation, vasomotor reactions, drop in blood pressure, etc. ).

With local dyskinesias, there are cramps of the tongue, trismus, hyperkinesis of facial muscles, gaze spasms (oculogiric crises), torticollis, opisthotonus, dyspnea, etc. An oral syndrome (Kulenkampff-Tarnow) has also been described, which is manifested by an unexpected tonic contraction of the muscles of the neck, mouth, protrusion of the tongue , impaired phonation and respiration. In some cases, these symptoms can be regarded as manifestations of epilepsy or infectious diseases of the central nervous system (meningitis, encephalitis, etc.).

Treatment . With the development of local dyskinesias, the most effective is intramuscular or intravenous administration of akineton (5 mg). In the absence of the drug, dyskinetic reactions can be stopped with chlorpromazine - 25-50 mg intramuscularly and 2 ml of a 20% caffeine solution subcutaneously. In case of generalized paroxysmal syndrome, the simultaneous administration of chlorpromazine or tizercin at a dose of up to 50 mg intramuscularly and antiparkinsonian correctors (akineton 5 mg intramuscularly) is indicated. Effective is the appointment of diazepam (Relanium) 20 mg intramuscularly. To prevent the recurrence of paroxysmal syndrome, antiparkinsonian correctors should be prescribed or the dosage of drugs already taken should be increased.

Acute extrapyramidal syndrome (acute parkinsonism)

It occurs in the first weeks of therapy and is characterized by the appearance of an amyostatic symptom complex in the form of general stiffness with a characteristic posture with arms bent at the elbows and brought to the body, tremor of the extremities, akathisia and tasikinesia and accompanying autonomic disorders (facial greasiness, sweating, seborrhea). The appearance of various hyperkinesias is also characteristic - choreiform, athetoid. Hyperkinesias are not persistent.

Treatment. Acute extrapyramidal syndrome is easily eliminated by prescribing or increasing the dose of antiparkinsonian correctors - cyclodol (6-12 mg / day orally), akineton (6-12 mg / day orally), tremblex (0.25-0.5 mg intramuscularly). The duration of action of Tremblex after a single intramuscular dose reaches 2-4 days.

Subacute extrapyramidal syndrome

In contrast to acute, it is characterized by the gradual development of neurological symptoms at more distant stages of therapy (day 40-60) and is characterized by hypokinesia with increased muscle tone, poverty and monotony of motor and facial manifestations, constant tremor, stereotypical hyperkinesis, autonomic disorders characteristic of parkinsonism . In the mental sphere, the following prevail: lethargy, adynamia, passivity of patients with anxious and depressive mood coloring in the presence of akathisia.

Treatment. The appointment of antiparkinsonian correctors in small doses is usually ineffective. Reduction of extrapyramidal phenomena can be achieved by prescribing higher doses of drugs (cyclodol 12-18 mg/day, akineton 12-24 mg/day). With the predominance of akathisia, it is recommended to use dinezin at a dose of 200 to 300 mg / day orally [Avrutsky G.Ya., Gurovich I.Ya., 1970]. Effective is the appointment of diphenhydramine, diazepam, clonazepam in medium therapeutic doses.

Protracted extrapyramidal syndrome

It occurs in the early stages of therapy, mainly in patients with cerebral organic insufficiency, and is characterized by the massiveness and torpidity of extrapyramidal manifestations in the form of akineto-hypertonic, hyperkinetic-hypertonic or hyperkinetic syndromes. After the abolition of antipsychotics, extrapyramidal symptoms, especially oral hyperkinesis, may persist for weeks and months, despite therapy with correctors. Extrapyramidal movement disorders are combined with autonomic disorders: hypersalivation, sweating, seborrhea. In some cases, autonomic dysfunctions occur - delay, involuntary urination, impaired swallowing. On the part of the mental status, apatho-adynamic or dreary depression is noted with a decrease in initiative, productivity, importunity and fussiness. Often there is insomnia, a violation of the rhythm of sleep.

Treatment. Antiparkinsonian correctors cyclodol, akineton, tremplex in medium and high doses, neurometabolic drugs (nootropil 1.6-2.4 g/day, picamilon 0.1-0.2 g/day, phenibut 0.5-1.5 g / day), restorative and vitamin therapy. Plasmapheresis is effective. On average, from 800 to 1500 ml of plasma can be removed per operation, followed by transfusion of plasma-substituting solutions. The course of treatment consists of 2-3 plasmapheresis operations. Plasmapheresis in patients with schizophrenia with prolonged akineto-hypertensive or hyperkinetic-hypertensive syndrome can significantly reduce or completely stop existing extrapyramidal disorders. In the process of treatment, almost all the symptoms that are part of the structure of a protracted extrapyramidal syndrome - akinesia, muscle hypertonicity, tremor, akathisia, hyperkinesias - undergo a significant reduction. Simultaneously with extrapyramidal motor disorders, the anguish, apathy, asthenia accompanying them decrease or completely disappear [Malin D.I., 1997].

Chronic extrapyramidal neuroleptic syndrome or tardive dyskinesia

They are one of the most severe neurological complications of neuroleptic therapy. Tardive dyskinesias are observed in approximately 20% of patients constantly taking antipsychotic therapy, and develop in approximately 5% of patients taking antipsychotics during the year.

According to I. Ya. Gurovich (1971), chronic extrapyramidal neuroleptic syndrome includes those disorders that do not show a tendency to regress within 6 months after the abolition of antipsychotics.

The clinical picture of this complication is characterized by the gradual development (against the background of long-term therapy with neuroleptics) of various hyperkinesias (oral, athetoid, choreiform, torsion-dystonic) with a tendency to their generalization. Often, hyperkinesias have a “functional” connotation, they increase in between courses of therapy, while other extrapyramidal disorders undergo a regression. Simultaneously with neurological persistent changes occur in the mental sphere. Their combination is described as a manifestation of psychopharmacotoxic encephalopathy [Gurovich I.Ya., Fleis E.P., 1969]. They are characterized by passivity of patients, increased psychophysical exhaustion, affective instability, slowing down of intellectual processes, importunity, as well as phenomena of "hysterization" of the psyche with a tendency to a demonstrative increase in existing hyperkinesis.

Treatment. The use of antiparkinsonian correctors with central anticholinergic activity in chronic extrapyramidal neuroleptic syndrome is ineffective. Some reduction in the severity of hyperkinesis can be achieved with the use of akineton, which, in our opinion, has a more effective effect on hyperkinetic manifestations compared to other antiparkinsonian drugs. In addition, the presence of an ampouled form allows the use of akineton for parenteral-intramuscular and intravenous drip, which enhances the therapeutic effect [Avrutsky G.Ya., Malin D.I., 1994]. A number of authors note the possibility of increasing dyskinesias with the use of anticholinergic correctors. Our studies have shown that anticholinergic correctors have a positive effect if parkinsonism in the form of an amyostatic symptom complex with a plastic increase in muscle tone is observed simultaneously with dyskinesias.

For the treatment of chronic extrapyramidal syndrome, the use of low doses of certain neuroleptics is recommended - sonapax 50-150 mg / day, leponex 50-100 mg / day and especially tiapride 200-400 mg / day, as well as benzodiazepines - diazepam 20-30 mg / day, clonazepam 2-6 mg/day. Abrupt withdrawal of neuroleptics can lead to increased hyperkinesis. The use of the antioxidant alpha-tocopherol (vitamin E) is effective. Due to the presence of cerebral organic insufficiency in many patients, neurometabolic drugs (nootropil, picamilon, pantogam, phenibut, etc.) should be included in the treatment regimen. It is also recommended baclofen 15-30 mg/day, sodium valproate 400-600 mg/day. When using these drugs, it is possible to achieve only a weakening of the severity of hyperkinesis, cases of complete cure are extremely rare.

The pathogenesis of chronic extrapyramidal syndrome has not yet been studied. It is assumed that the development of chronic hyperkinesis is associated with hypersensitivity of dopamine receptors. It is possible that autoimmune mechanisms may be involved in this process. Recently, it has been found that the autoimmune process can directly affect the structures of the dopamine system at the level of dopamine receptors with the formation of anti-receptor antibodies with a stimulating and blocking effect [Kolyaskina G.I., Sekirina T.P., 1990]. From these positions, the use of extracorporeal detoxification methods that have a detoxifying and immunocorrective effect can be theoretically justified.

The results of our own research have shown that several plasmapheresis operations with the removal of 800 to 1600 mg of plasma and subsequent plasma replacement with colloidal and crystalloid solutions can achieve a significant reduction in the severity of hyperkinesis. Simultaneously with a decrease in motor disorders during plasmapheresis, an improvement in mental and general physical condition is observed - a decrease in lethargy, apathy, increased activity, improved sleep, and appetite. Thus, along with extrapyramidal symptoms during plasmapheresis, manifestations of the psychoorganic syndrome are also reduced [Malin D.I., 1997].

Prevention of complications should be based on the consideration of risk factors. It has been established that chronic extrapyramidal neuroleptic syndrome occurs most often with the following predisposing factors:

1. the presence of cerebral organic insufficiency;
2. elderly age ;
3. the duration of the use of neuroleptics, especially piperazine 62 derivatives of phenothiazine and butyrophenones;
4. propensity to develop massive extrapyramidal symptoms with a predominance of prolonged hyperkinesis.

In the presence of these factors, especially when they are combined, therapy should be carried out with extreme caution, taking into account the possibility of complications [Avrutsky G.Ya., Gurovich I.Ya., Gromova V.V., 1974].

convulsive syndrome

The appearance of convulsive seizures from small to generalized can be observed during treatment with chlorpromazine [Zak NA, 1957; Schlieter S., 1956]. More often, the development of seizures, in the treatment of chlorpromazine, is observed in patients with increased convulsive activity of the brain. There are indications of a decrease in the threshold of convulsive activity in the treatment of neuleptil, triftazin, risperidone and a number of other antipsychotics.

It was noted that in patients taking clozapine (leponex, azaleptin), convulsive seizures develop more often than in people receiving other drugs. This phenomenon is related to the dose of clozapine. At low and moderate doses, the frequency of seizures is comparable to the frequency of seizures in the treatment of phenothiazines (approximately 1-2% of treated patients). At a dose of 600-900 mg of clozapine, seizures are observed in more than 5% of patients. Therefore, clozapine should be used with caution in patients with epilepsy.

Treatment. Dose reduction or withdrawal of antipsychotics. Administration of anticonvulsants. An epileptic seizure can be stopped by intravenous administration of Relanium at a dose of 10-20 mg per 10 ml of a 40% glucose solution. The episyndrome must be differentiated from paroxysmal extrapyramidal syndrome (early dyskinesia), since in the latter case, the treatment tactics will be fundamentally different (see Treatment of paroxysmal extrapyramidal syndrome).

Syndromes of lesions of the subcortical region

The defeat of the corpus callosum is characterized by mental disorders, increasing dementia, memory loss, orientation in space is disturbed, and apraxia of the left hand develops.

The thalamic Dejerine-Roussy syndrome is characterized on the opposite side by hemianesthesia, sensitive hemiataxy, and thalamic pain. There is a thalamic hand, choreo-athetoid hyperkinesis, and violent laughter and crying.

Hypothalamic syndrome consists of disorders of carbohydrate, fat, protein metabolism, disorders of the cardiovascular, respiratory and gastrointestinal systems. There may be obesity, cachexia, impotence, menstrual irregularities. Sleep and wakefulness disturbance.

With the defeat of the epithelium: accelerated puberty, increased growth, ataxia are observed.

Foreign lesion syndrome (metathalamus): damage to the external and internal geniculate bodies is characterized by hearing loss, homonymous (central and peripheral) hemianopsia.

Syndromes of damage to the internal capsule: hemianesthesia, hemiplegia and hemianopsia on the opposite side. Syndrome of damage to the radiant crown: hemiparesis, hemihypesthesia, monoparesis, monoplegia with uneven damage to the arms and legs.

Parkinson's syndrome: akinesia, hypokinesia, oligokinesia, plastic hypertension of the muscles, a symptom of "cog wheel", "wax doll", throwing to the sides when walking, parkinsonian marking time, slowness of thinking, paradoxical movements.

There may be an increase in postural reflexes, a quiet monotonous voice, a violation of posture and gait (the head and torso are tilted forward, the arms are bent at the elbow and wrist joints, the legs are at the knees and are slightly adducted), pallidar tremor is characteristic.

Syndrome of lesions of the striatum (hypotonic-hyperkinetic syndrome): hypotension, chorea, athetosis, choreoathetosis, facial hemispasm, facial paraspasm, hemitremor, torsion spasm, myoclonus; tics, blepharospasm, platysma spasm, torticollis. When the subthalamic nucleus (Lewis body) is damaged, hemiballismus is observed.

subcortical region

Subcortical formations are an accumulation of gray matter closest to the cerebral cortex. Caudate nucleus formed from the anterior bladder and is closer in origin to the cerebral cortex. Lenticular nucleus subdivided into shell and pale ball. Close in structure, the shell and the caudate nucleus, as well as later formations, made up the nucleus, called the striatum (striatum). The pale ball (pallidum) is an older formation, an antagonist of the striatum. The striatum and globus pallidus form a strio-pallidar system. Almond nucleus closely related to the limbic region. The meaning of the fence is unclear.

The structure of the subcortical nodes is quite complicated. Thus, the striatum is characterized by the presence of both large and small polygonal cells, characterized by chromatophilic cytoplasm and a large number of dendrites. The structure of the pale ball is dominated by triangular and spindle-shaped cells, many fibrous formations.

The subcortical nodes are connected to each other, as well as to the cortex, diencephalon and midbrain. The connection of the subcortical nodes with the cortex is carried out through the visual tubercle and its conductors. Some researchers recognize the existence of a direct connection between the cortex and subcortical nodes.

The subcortical nodes are surrounded by white matter, which has a peculiar name - a bag. There are inner, outer and outer bags. Various pathways run in the bags, connecting the cortex with the underlying areas and directly with the subcortical nodes. In particular, the pyramidal pathway, which connects the cortex with different floors of the brain and spinal cord, passes through the internal bag. The close connection of subcortical formations with vegetative centers indicates that they are regulators of vegetative functions, perform emotionally expressive, protective movements and automatic settings, regulate muscle tone, and refine auxiliary movements when changing body position.

Much attention was paid to the study of the activity of the basal ganglia by I.P. Pavlov, considering the subcortex as an accumulator of the cortex, as a strong energy base that charges the cortex with nervous energy. Characterizing the interaction of the cortex and subcortex, I.P. Pavlov wrote: “Summing up everything I have said about the activity of the cortex, we can say that the subcortex is a source of energy for all higher nervous activity, and the cortex plays the role of a regulator in relation to this blind force, subtly directing and restraining it”1.

The pallidum, as an older formation of the subcortex, is closely associated with the red nuclei, from which the extrapyramidal path (Monaco's bundle) begins, carrying impulses from all parts of the brain located below the cortex to the anterior horns of the spinal cord. This is the path of unconditioned reflexes.

The diencephalon was formed from the second brain bladder, is located on the inner surface of the hemispheres under the corpus callosum and fornix, includes two visual tubercles (in each of the hemispheres). Between them, a narrow gap (traces of the former cerebral bladder), called the third ventricle, has been preserved. Under the bottom of the third ventricle there is a hypothalamic (hypothalamic) area, closely connected with the pituitary gland (endocrine glands) by bilateral connections and forming a neuroendocrine system (Fig. 38).

The visual hillock (thalamus) is present in each hemisphere. Between themselves, both visual hillocks are connected by a gray commissure. In the gray commissure there are paths connecting the nuclei of both visual hillocks.

The visual hillock consists of three main nuclei: anterior, internal and external. In the area of ​​\u200b\u200bcontact of the outer and inner nuclei is the middle nucleus, or Lewis body.

Histologically, the nuclei of the thalamus are composed of ganglionic multipolar cells. The cells of the outer nucleus contain chromatophilic grains. From above, the visual tubercle is covered with a layer of myelin fibers. The nuclei of the thalamus are connected by wide bilateral connections with the cerebral cortex and subcortical formations. Nerve pathways from the underlying sections, from the middle, posterior and spinal cord, also approach the visual tubercle; in turn, reverse nerve pathways also run from the thalamus to these departments.

Nerve fibers approaching the optic tubercle from the underlying sections carry impulses of various types of sensitivity. So, the fibers of the internal (medial) loop, as well as the fibers of the spinal cerebellar tract, the sensory path of the trigeminal nerve, the fibers of the vagus and trochlear nerves, approach the outer core of the thalamus. The nuclei of the thalamus are also connected by numerous connections with other parts of the diencephalon. Thus, the endings of the paths of all types of sensitivity are concentrated in the visual hillocks.

Special formations, the cranked bodies, are closely adjacent to the visual mounds. In each hemisphere, the inner and outer geniculate bodies are distinguished. In the cranked bodies there are accumulations of gray matter that forms the nuclei of these bodies.

Behind the visual hillock (slightly lower) is a special formation - the pineal gland (endocrine gland). Dysfunction of the pineal gland is often observed in children with organic lesions of the central nervous system.

The hypothalamus (hypothalamus) is located under the visual tubercle and is the bottom of the third ventricle. A gray tubercle is distinguished here, the top of which is turned down. The gray tubercle is formed by a thin gray plate; gradually thinning, it passes into a funnel, at the end of which there is a lower cerebral appendage - the pituitary gland. Behind the gray tubercle lie two semicircular formations - mastoid bodies related to the olfactory system. Anterior to the gray tubercle is the optic chiasm (chiasm). Several nuclei are also allocated in the hypothalamus. The nuclei of the gray tubercle are formed by small bipolar cells of a rounded and polygonal shape. Above the optic cord is the supra-optic nucleus, above, in the wall of the third ventricle, is the paraventricular nucleus.

The extrapyramidal system is a deep and ancient system of regulation of movements at an unconscious level. In our distant ancestors - fish, amphibians, it is the main and only one. In mammals and humans, its meaning has changed. It regulates muscle tone, unconscious motor responses, maintaining balance, and participates in the automation of stereotyped movements. Quite often, neurologists notice such phenomena and symptoms that indicate the occurrence of extrapyramidal diseases. What are the symptoms of damage to the extrapyramidal system? This will be discussed.

You can't embrace the immensity

The symptomatology and treatment of extrapyramidal disorders is a whole section of neurology, and there is even a specialization in this area, just as there are separate outpatient and even inpatient centers in which diseases of the extrapyramidal nervous system are diagnosed and treated. Therefore, we will limit ourselves to describing only the main features that characterize extrapyramidal disorders. Such a “mosaic” approach is quite enough to arouse interest in the topic, and even teach the basics of “visual diagnostics”. Now, when you see a "strange" person on the street, you may tell your companions what is happening to him.

Syndromology

In total, there are several dozens of different diseases of the nervous system associated with the "subcortex", and if we add variants of the course to this, we get an impressive list. But all this variety of "patterns", as in a kaleidoscope, can be made up of small individual extrapyramidal actions that have been violated. This is how extrapyramidal symptoms were formed. These include general disorders such as impaired muscle tone and movement.

Violations of tone

Changes in muscle tone, manifested either by diffuse or limited hypotension of the muscles (this is quite rare), or by a significant increase (they say, rigid muscles) is the first and important symptom.

Hypotension is defined as lethargy and complete compliance, the amplitude in large joints is excessively large. As you know, a normal, physiological tone still provides some resistance when you try to bend and unbend even a completely relaxed arm. It feels like you are bending and unbending the arm of a living person. In the case of muscular hypotension, extrapyramidal disorders are manifested by the symptom of "puppet hands". You cannot get rid of the impression that you are moving a dangling puppet hand.

Extrapyramidal rigidity is a diffuse increase in tone or muscle hypertension. In this case, the resistance of the arm, or leg, which cannot relax, is constant from the very beginning of the movement to the end. Extrapyramidal symptoms in this case resembles a "cogwheel". Muscles have forgotten how to work smoothly and move in tiny “jerks”, which resembles the intermittent movement of a cogwheel. In the event that the "gear" has a very small "step", then we can talk about waxy flexibility. In any case, the resistance that the patient's muscle provides is significant and constant. This defeat is characteristic of Parkinson's disease, which directly embodies many extrapyramidal disorders.

movements

But muscle tone can be pathologically altered both during movement and at rest. It is not an indicator of a disorder of automatic movements, but only a violation of the preparation for them. Therefore, there are also unconscious changes in motor activity, namely hypokinesia (impoverishment of movements), and hyperkinesis, which are manifested by a variety of movements.

A special, mixed variant of movement disorders with an increase in tone is tremor, or regular trembling, which occurs in a single rhythm. Tremor, like other dyskinesias, disappear during sleep, both in adults and children, and appear upon awakening. Tremor may be present in various diseases, such as parkinsonism, or may be the only symptom. In some cases, the presence of tremor allows the diagnosis of endocrine pathology (it can occur, for example, with thyrotoxicosis).

With subcortical syndromes, there is often a "commonwealth" of the effects of dystonia (impaired tone) with dyskinesias (disorders of movement). Often rigidity is combined with hypokinesia (bradykinesia, oligokinesia), for example, in Parkinson's disease. Conversely, muscular hypotonia is associated with hyperkinesis, for example, with chorea. The latter combination occurs when the neostriatum is affected, and rigidity and hyperkinesis appear when the substantia nigra is damaged. It is about this phenomenon that we will talk in more detail.

parkinsonism

At first glance, if the extrapyramidal nervous system "manages" unconscious movements, then extrapyramidal disorders should be expressed in motor disorders. When the pyramidal tracts are damaged, paralysis occurs. In the event that it is complete, and no movements are possible, it is called plegia, and with partially preserved function, neurologists call it paresis. What does "unconscious paralysis" look like? At first glance, this phenomenon is simply impossible to imagine. But it turns out that there is such an extrapyramidal pathology as "shaking paralysis", or Parkinson's disease. Probably everyone has heard such a neurological diagnosis.

Parkinsonism occurs when neurons in the substantia nigra lose the pigment melanin.. As a result, their degeneration occurs, the loss of dopamine begins. The same process occurs in the striatum. Most often, EPS (extrapyramidal symptoms) appears symmetrically and for an unknown reason. This is Parkinson's disease. But sometimes extrapyramidal insufficiency occurs on the one hand. This happens when, for example, there is a reason: hemorrhage or thrombosis of the corresponding vessels (stroke). As a result, secondary parkinsonism develops, and on the opposite side of the body.

Unfortunately, every third case of parkinsonism is drug-induced and is associated with the abuse of antipsychotics, due to the development of neuroleptic syndrome. Often this occurs in drug addicts and substance abusers who use chlorpromazine, haloperidol and other drugs, not knowing the consequences.

Clinic

Probably, those people who want to understand what extrapyramidal movement disorders are should be shown a patient with Parkinson's disease. Of course, he will not dance and jump, as in a chorea, his face will not distort with violent laughter, and his fingers will not make bizarre and worm-like movements, as in athetosis. But, according to the totality of clinical signs, it is parkinsonism that is studied by students in the first place. Judge for yourself. The characteristic clinical and neurological signs of parkinsonism are:

• akinesia (impoverishment of all conscious movements, complete absence of gestures);
• propulsion, retropulsion, lateropulsion. The patient begins to move with great difficulty, and once he starts, he cannot finish it. His last steps, respectively, are directed forward, backward or sideways;
• amimia, hypomimia (mask-like face), on which moving eyes simply “live”. A patient with parkinsonism does not lose the mobility of the oculomotor muscles, and there is no "cog" phenomenon in them. Therefore, it is easier for such a patient to communicate with his eyes, for example, by pointing to an object, instead of saying words or starting such a painful movement;
• dysarthria and monotonous speech. The speech component joins because there is a rigidity of the tongue and vocal muscles;
• there is a tremor, according to the type of "counting coins", mainly in the hands, thumbs and forefingers.

Perhaps one of the most striking manifestations of parkinsonism is the “falling head” test. If a patient lying on his back raise his head and sharply remove his hands, then any normal person's head will hit the couch. Parkinson's does not have this reaction. Due to "toothed" hypertonicity, the head slowly, with barely noticeable jerks, falls onto the couch.

In addition to parkinsonism, which is a classic example of rigidity and hypertension, consider its alternative - extrapyramidal hypotonicity-hyperkinesia syndrome.

Hyperkinesis, or damage to the neostriatum

We present the second, large group of subcortical or subcortical disorders, which are based on excessive motor activity. In addition to the defeat of the striatum, it is also possible to defeat the most ancient structure - the pale ball. As a result, a pallidar syndrome occurs, which is sometimes called striopallidar.

Morphologically, these diseases are situations in which the influence of the striatum on the “subordinate structures” is sharply weakened, and the most diverse circulation of motor impulses occurs until the signal is spontaneously attenuated. The main representatives of this group of diseases are:

• Athetosis.

This disease occurs when a network of small neurons in the striatum dies and is replaced by glial scars. As a result, the patient has bizarre, worm-like and extremely bizarre movements. There is a tendency to overextend, "wring" fingers. In addition, there are grimaces of the tongue and facial muscles, laughter or crying may appear;

• Torsion spasm or torsion dystonia.

This is nothing more than athetosis of the muscles of the trunk. At the same time, the movements are no less bizarre and resemble wriggling ones. Speaking figuratively, this is "the entry of a corkscrew into a bottle." In such patients, as a result, gait is very difficult. Dystonic motor activity is nothing more than rhythmic muscle spasms of agonists - antagonists.

Here we must make a digression, after which the very physical basis of all violent movements may become clear. Normally, after contraction, the muscle simply relaxes and goes into a state of rest. But in this case, the inhibitory influences are blocked. The muscle cannot simply relax. And, in order to somehow replace complete relaxation, there is an alternate contraction of the muscles of agonists - antagonists, "pulling" in opposite directions.

The second variant of hyperkinesis, in which the shell and the central median thalamic nucleus is affected, is spastic torticollis. The sternocleidomastoid and trapezius muscles are often affected. The result is movements, involuntary and slow, that pull and turn the head sideways and down. Often it needs to be supported by hand.

• Chorea.

This is an interesting subcortical syndrome, which is manifested by rapid, completely chaotic movements in the muscles, which are very reminiscent of arbitrary ones. It is even difficult for a simple person to understand that they are not playing a trick on him and that they are not “playing the fool” in front of him. With chorea, a dancing, bouncing gait, grimacing occurs. Of greatest importance is

LECTURE No. 5. Extrapyramidal system. Syndromes of her defeat

The extrapyramidal system includes conduction and motor pathways that do not pass through the pyramids of the medulla oblongata. These pathways regulate feedback between the spinal cord, brainstem, cerebellum, and cortex. The extrapyramidal system includes the caudate nucleus, the shell of the lenticular nucleus, the pale ball, the subthalamic nucleus, the substantia nigra and the red nucleus.

The center of this system is the spinal cord. The reticular formation is located in the tegmentum of the spinal cord. The striatum receives impulses from different parts of the cerebral cortex. Most of the impulses come from the frontal motor cortex. The fibers are inhibitory in their action. The other part of the fibers goes to the striatum of the thalamus.

Afferent fibers from the caudate nuclei and the shell of the lenticular nucleus go to the pale ball, namely to its lateral and medial segments. These segments are separated from each other by the internal medullary plate, and there is also a connection between the cerebral cortex and the red nucleus, the substantia nigra, the reticular formation and the subthalamic nucleus. All of the above fibers are afferent.

The substantia nigra has connections with the putamen and the caudate nucleus. Afferent fibers reduce the inhibitory function of the striatum. Efferent fibers have an inhibitory effect on nigrostriatal neurons.

The first type of fiber is dopaminergic, the second is GABAergic. Part of the efferent fibers of the striatum passes through the pale ball, its medial segment. The fibers form thick bundles, one of which is a lenticular loop. Most of these fibers travel from the globus pallidus to the thalamus. This part of the fibers makes up the pallidothalamic bundle, ending in the anterior nuclei of the thalamus. In the posterior nucleus of the thalamus, fibers originating from the dentate nucleus of the cerebellum end.

The nuclei of the thalamus have bilateral connections with the cortex. There are fibers that run from the basal ganglia to the spinal cord. These connections help to perform arbitrary movements smoothly. The function of some formations of the extrapyramidal system has not been elucidated.

Semiotics of extrapyramidal disorders. The main symptoms of disorders of the extrapyramidal system are dystonia (impaired muscle tone) and disorders of involuntary movements, which are manifested by hyperkinesis, hypokinesis and akinesis.

Extrapyramidal disorders can be divided into two clinical syndromes: akinetic-rigid and hyperkinetic-hypotonic. The first syndrome in its classical form manifests itself in Parkinson's disease.

In this pathology, damage to the structures of the nervous system is degenerative and leads to the loss of neurons of the substantia nigra containing melanin, as well as to the loss of dopaminergic neurons associated with the striatum. If the process is one-sided, then the manifestation is localized on the opposite side of the body.

However, Parkinson's disease is usually bilateral. If the pathological process is hereditary, then we are talking about trembling paralysis. If the reason for the loss of neurons is different, then it is Parkinson's disease or parkinsonism. Such causes may be cerebral syphilis, cerebral atherosclerosis, typhoid fever, damage to the midbrain during a tumor or injury, intoxication with various substances, long-term use of reserpine or phenothiosine. Postencephalitic parkinsonism is also distinguished, which is a consequence of lethargic encephalitis. Akineticorigidny syndrome is characterized by a triad of symptoms (akinesis, rigidity, tremor).

Akinesis is manifested by a slow decrease in mobility, with a gradual loss of facial and expressive movements. It is difficult for the patient to start walking. Having started any movement, the patient may stop and take several unnecessary movements or steps. This is due to a slowdown in counternervation, which is called propulsion, retropulsion or lateropulsion and depends on the direction of additional movements.

Facial expression is characterized by hypo- or amimia, which is explained by inhibition of the movement of facial muscles. Speech also suffers as a result of rigidity and tremor of the muscles of the tongue. She becomes dizzy and monotonous. The patient's movements become slow and unfinished. The whole body is in a state of anteflexion. Rigidity is manifested in the extensor muscles.

Examination reveals the phenomenon of a gear wheel. It lies in the fact that during passive movements in the limbs there is a stepwise decrease in the tone of the muscles of the antagonists. A head drop test is often performed: if the raised head of the patient lying on his back is abruptly released, then it is gradually released back, and does not fall. There is no increase in reflexes, as well as pathological reflexes and paresis.

All reflexes become difficult to evoke. The tremor is passive. Its frequency is 4–8 movements per second; in parkinsonism, the tremor is antagonistic, that is, it occurs as a result of the interaction of muscles that are opposite in function.

This tremor stops when targeted movements are performed. The mechanisms by which the triad of symptoms occurs in parkinsonism have not been fully elucidated. It has been suggested that akinesis results from the loss of transmission of impulses to the striatum.

Another cause of akinesis may be damage to the neurons of the substantia nigra, leading to the cessation of efferent impulses of inhibitory action. Muscle stiffness can also occur due to loss of substantia nigra neurons. With the loss of these neurons, there is no inhibition of efferent impulses to the striatum and globus pallidus. Antagonistic tremor in parkinsonism can develop in the cells of the spinal cord, which begin to transmit impulses to motor neurons in a rhythmic manner. At the same time, the inhibitory impulses transmitted through the same cells from the striatum do not reach the spinal cord.

Hyperkinetic-hypotonic syndrome occurs as a result of damage to the striatum. Hyperkinesis in this syndrome appears when the inhibitory neurons of the neostriatum are damaged.

Normally, impulses from these neurons go to the globus pallidus and the substantia nigra. When these cells are damaged, an excessive amount of excitatory impulses enters the neurons of the underlying systems. As a result, athetosis, chorea, spastic torticollis, torsion dystonia, and ballism develop.

Athetosis, as a rule, develops as a result of perinatal lesions of the striatum. It is characterized by slow, worm-like involuntary movements. Overextension of the distal extremities is noted. Muscle tension rises spasmodically alternately in agonist and antagonist muscles. Arbitrary movements are disturbed, as spontaneously arising hyperkinetic movements are noted. These movements can involve the muscles of the face and tongue. In some cases, spasmodic attacks of laughter or crying are noted.

Facial paraspasm is a tonic contraction of the muscles of the face of a symmetrical nature. Hemi- or blepharospasm may be noted. This pathology consists in an isolated contraction of the circular muscles of the eyes. In some cases, this contraction is combined with convulsions of the muscles of the tongue or mouth of a clonic nature. Facial paraspasm does not manifest itself in sleep, increases with bright light or excitement.

Choreic hyperkinesis appears in the form of short twitches of an involuntary nature. These movements develop randomly in different muscle groups, causing a variety of movements. Initially, movement is noted in the distal, and then in the proximal limbs. This hyperkinesia can affect the muscles of the face, causing grimaces to appear.

Spasmodic torticollis as well as torsion dystonia are the most important syndromes of dystonia. They develop as a result of damage to the shell neurons, the centromedian nucleus of the thalamus and other nuclei of the extrapyramidal system. Spasmodic torticollis is manifested by spastic contractions of the neck muscles.

This pathology manifests itself in the form of involuntary head movements, such as turns and tilts. Also, the sternocleidomastoid and trapezius muscles may be involved in the pathological process. Torsion dystonia is manifested by the movements of the trunk, as well as the proximal parts of the limbs in the form of rotation and turns.

Sometimes these movements are so pronounced that the patient cannot walk or even stand. Torsion dystonia is symptomatic and idiopathic. Symptomatic occurs with birth trauma, encephalitis, hepatocerebral dystrophy, jaundice and early Huntington's chorea.

Ballistic syndrome consists in fairly rapid contractions of the muscles of the proximal limbs, which are of a rotating nature. Movements in this pathology are sweeping due to the contraction of sufficiently large muscle groups. The cause of the pathology is the defeat of the subthalamic nucleus, as well as its connection with the pale ball. This syndrome appears on the side opposite the lesion.

Myoclonic twitches result from damage to the red nucleus, the central tegmental tract, or the cerebellum. They are manifested by rapid contractions of different muscle groups, which are erratic.

Tics are manifested in the form of rapid muscle contractions of an involuntary nature. In most cases, facial muscles are affected.

Conservative methods of treatment do not always lead to a positive effect. Stereotaxic intervention is used, which is based on the fact that when the striatum is damaged, its inhibitory effect on the pale ball and substantia nigra is lost, which leads to an excessive stimulating effect on these formations.

It is assumed that hyperkinesis occurs under the influence of pathological impulses to the nuclei of the thalamus and to the cerebral cortex. It is important to interrupt this pathological impulse.

In old age, cerebral atherosclerosis often develops, leading to hyperkinesis and parkinson-like disorders. It is most often manifested by the repetition of phrases, words or syllables, as well as some movements. These changes are associated with necrotic foci in the striatum and globus pallidus. These foci are found postmortem in the form of small cysts and scars - lacunar status.

Automated actions are a variety of movements and complex motor acts that occur without conscious control.

Clinically manifested on the side of the lesion, the cause of the pathology is a violation of the connection of the cerebral cortex with the basal ganglia. At the same time, the connection of the latter with the brain stem is preserved.