Study of coordination of movements

Violations of coordination of movements are designated by the term "ataxia". Ataxia is the mismatch of the work of various muscle groups, leading to a violation of the accuracy, proportionality, rhythmicity, speed and amplitude of voluntary movements, as well as to a violation of the ability to maintain balance. Violations of coordination of movements can be caused by the defeat of the cerebellum and its connections, disorders of deep sensitivity; asymmetry of vestibular influences. Accordingly, distinguish cerebellum, sensitive and vestibular ataxia.

Cerebellar ataxia

The hemispheres of the cerebellum control ipsilateral limbs and bear the main responsibility for the coordination, smoothness and accuracy of movements in them, especially in the hands. The worm of the cerebellum largely controls the gait and coordination of the movements of the trunk. The cerebellar ataxia is divided into static-locomotor and dynamic. Static-locomotor ataxia manifests itself mainly in standing, walking, trunk movements and proximal limbs. It is more characteristic for the defeat of the cerebellum worm. Dynamic ataxia manifests itself in arbitrary movements of the limbs, mainly their distal sections, it is characteristic for the defeat of the hemispheres of the cerebellum and arises on the side of the lesion. Cerebellar ataxia is particularly noticeable at the beginning and at the end of the movements. Clinical manifestations of cerebellar ataxia are as follows.

• Terminal (noticeable at the end of the movement) dysmetry (mismatch of the degree of muscle contraction that is necessary for the precise performance of movement, the movements are often too sweeping - hypermetria).
• Intensive tremor (jitter arising in the moving limb as it approaches the target).

Sensitive ataxia develops when the function of the pathways of deep musculo-articular sensitivity is disturbed, more often in the pathology of the posterior cords of the spinal cord, less often in the lesions of the peripheral nerves, posterior spinal roots, medial loop in the brainstem or thalamus. The lack of information about the position of the body in space causes a violation of the reverse afferentation and ataxia.

To detect a sensitive ataxia, samples are used for dysmetry (finger-nasal and heel-knee, tests for finger-drawing of the drawn circle, drawing in the air of the eight); on adiadochokinesis (pronation and supination of the hand, flexion and extension of the fingers). Also check the function of standing and walking. All these tests are asked to perform with closed and open eyes. Sensitive ataxia decreases with visual control and increases when the eyes are closed. Intensive tremor for sensitive ataxia is not typical.

Sensitive ataxia can cause "posture fixation defects": for example, when the visual control is turned off, the patient holding his hands in a horizontal position experiences slow movement of the hands in different directions, as well as involuntary movements in the hands and fingers reminiscent of athetosis. Keep limbs in extreme positions of flexion or extension can be easier than in average poses.

Sensitive ataxia with isolated lesions of the spinal cord pathway occurs rarely and is not accompanied by a violation of deep sensitivity (since these pathways even carry impulses from proprioceptors of muscles, tendons and ligaments, but are not related to signals that are projected into the postcentral gyrus and create a feeling position and motion of the limbs).

Sensitive ataxia in the defeat of the pathways of deep sensitivity in the brainstem and in the thalamus is found on the side opposite the focus (at localization of the focus in the caudal sections of the brainstem, in the area of the medial loop cross, ataxia can be bilateral).

[1], [2], [3], [4], [5], [6], [7], [8]

Standing function

The ability of a person to maintain the vertical position of the body depends on sufficient muscle strength, on the ability to obtain information on body posture (feedback), as well as on the ability to instantly and accurately compensate for those body torsions that threaten balance. The patient is offered to become as he usually stands, that is, to take his natural posture in a standing position. Estimate the distance between the stops, which he involuntarily chose to maintain equilibrium. Ask the patient to stand upright, connect the feet (heels and socks together) and look straight ahead. The doctor should stand next to the patient and be ready at any time to support him. Pay attention to whether the patient deviates to any one side and whether the instability increases when closing the eyes.

A patient who is not able to stand in the position of "foot together" with his eyes open, is most likely to have a pathology of the cerebellum. Such patients walk with widely spaced legs, unstable when walking; it is difficult for them in the absence of support to maintain their balance not only when standing and walking, but also in a sitting position.

The symptom of Romberg lies in the inability of the patient with closed eyes to keep his balance in a standing position with tightly pushed feet. For the first time this symptom was described in patients with dorsal, that is, with damage to the posterior cord of the spinal cord. The instability in such a posture with closed eyes is typical for a sensitive ataxia. In patients with cerebellar lesions, instability in Romberg's posture is revealed even with open eyes.

Gait

The analysis of walking is very important for diagnosis of diseases of the nervous system. It should be remembered that imbalances in walking can be masked by various compensatory techniques. In addition, gait disorders are caused not by neurologic, but by other pathologies (eg, joint damage).

The gait is best assessed when the patient does not know what is being observed: for example, when he enters the doctor's office. The walk of a healthy person is fast, springy, light and energetic, and keeping the balance when walking does not require special attention or effort. Hands when walking slightly bent at the elbows (palms facing the hips) and the movements are performed in time with the steps. Additional tests include checking the following types of walking: walking the usual step in the room; walking "on the heels" and "on the toes"; "Tandem" walking (on the ruler, heel to toe). When carrying out additional tests, one must start from common sense and offer the patient only those tasks that he can actually perform at least partially.

The patient is asked to walk around the room quickly. Pay attention to the pose while walking; on the effort required to initiate walking and stopping; by the length of the step; rhythmic walking; presence of normal friendly hand movements; involuntary movements. Evaluate how widely he puts his feet when walking, tears his heels off the floor, does not "catch up" with one leg. Offer the patient to make turns during walking and pay attention to how easy it is to make a turn; whether the balance is lost at the same time; how many steps it should take to turn 360 ° around its axis (normally this turn is done in one or two steps). Then they ask the examinee to walk first on the heels, and then on the toes. Assess whether he tears off the heels / socks from the floor. Especially important is the test with walking on the heels, as the back flexing of the foot suffers with many neurological diseases. Watch as the patient performs the task to walk along an imaginary straight line so that the heel of the foot making a step is directly in front of the toes of the foot of the other leg (tandem walking). Tandem walking is a test more sensitive to imbalances than Romberg's. If the patient performs this test well, other tests for the stability of the vertical posture and ataxia of the trunk are likely to be negative.

Gait disturbance occurs with a variety of neurological diseases, as well as with muscular and orthopedic pathologies. The nature of the disorder depends on the underlying disease.

• Cerebral gait: when walking, the patient spreads his legs widely; unstable in standing and sitting positions; has a different length of steps; deviates to the side (with unilateral damage to the cerebellum - toward the hearth). The cerebellar gait is often described as "shaky" or "drunk walk", it is observed with multiple sclerosis, cerebellar tumors, hemorrhage or cerebellar infarction, cerebellar degeneration.
• Gait with posterior ctenopathy sensitive ataxia ("tabetic" gait) is characterized by pronounced instability in standing and walking, despite good leg strength. The movements in the legs are jerky, sharp, when walking, attention is drawn to the different length and height of the step. The patient looks intently at the road in front of him (his gaze is "chained" to the floor or ground). Characteristic is the loss of muscle-joint feeling and vibration sensitivity in the legs. In the Romberg pose, with closed eyes, the patient falls. Tabetic gait, in addition to dorsal dryness, is observed in multiple sclerosis, compression of the posterior cord of the spinal cord (for example, by a tumor), funicular myelosis.
• The hemiplegic gait is observed in patients with spastic hemiparesis or hemiplegia. The patient "drags" the straightened paralyzed leg (there is no flexion in the hip, knee, ankle), its foot is rotated to the inside, and the outer edge touches the floor. At each step, the paralyzed leg describes a semicircle, behind the healthy leg. The arm is bent and brought to the trunk.
• The paraplegic spasmodic gait is slow, with small steps. The toes of the feet touch the floor, legs when walking with difficulty break away from the floor, "cross" because of the increase in the tone of the adductor muscles and do not bend well in the knee joints due to the increase in the tone of the extensor muscles. Observe it with bilateral damage to pyramidal systems (with multiple sclerosis, ALS, prolonged compression of the spinal cord, etc.).
• Parkinsonic gait shuffling, small steps, typical propulsions (the patient on the move begins to move faster and faster, as if catching up with his center of gravity, and can not stop), difficulties in initiating and completing walking. The body when walking is tilted forward, the arms are bent in the elbow joints and are pressed to the trunk, while walking are motionless (aheyrokinesis). If the patient is slightly pushed into the chest, he begins to move backward (retropulse). In order to turn around its axis, the patient is required to make up to 20 small steps. When walking, there may be "congestion" in the most uncomfortable position.
• Steppazh ("cock" gait, stamping gait) is observed when the dorsiflexion of the foot is disturbed. The toe of the hanging foot touches the floor when walking, so the patient, when walking, is forced to lift his leg high and throw it forward, while he slaps the front of the foot against the floor. Steps are of equal length. One-sided stepping is observed with affection of the common peroneal nerve, bilateral - with motor polyneuropathy, both congenital (Charcot-Marie-Toot disease) and acquired.
• "Duck" gait is characterized by swinging the pelvis and rolling from one foot to the other. It is observed with bilateral weakness of the muscles of the pelvic girdle, primarily the middle gluteus muscle. With the weakness of the muscles that divert the hip, in the standing phase on the affected leg, the pelvis is lowered on the opposite side. The weakness of both middle gluteal muscles leads to a bilateral disruption of the fixation of the thigh of the supporting leg, the pelvis during walking is excessively lowered and rises, the trunk is "overtaken" from side to side. Because of the weakness of the other proximal muscles of the legs, patients experience difficulties in climbing the stairs and getting up from the stool. The rising from the sitting position is performed with the help of the hands, and the patient rests against the thigh or knee with brushes and only thus can straighten the trunk. Most often, this gait is observed with progressive muscular dystrophies (PMD) and other myopathies, as well as with congenital dislocation of the hips.
• Dystonic gait is observed in patients with hyperkinesis ( chorea, athetosis, muscular dystonia). As a result of involuntary movements, the legs move slowly and awkwardly, involuntary movements are observed in the hands and trunk. This gait is called "dancing", "jerking".
• Antalgic gait is a reaction to pain: the patient spares the sick leg, moving it very carefully and trying to load mainly the second, healthy leg.
• Hysterical gait can be very different, but does not have those typical signs that are typical for certain diseases. The patient may not at all tear his foot off the floor, dragging it, may show repulsion from the floor (like when skating) or may stagger from side to side, avoiding, however, falls, etc.

Involuntary pathological movements

Involuntary violent movements that interfere with the performance of voluntary motor acts are designated by the term "hyperkinesis". If the patient has hyperkinesias, it is necessary to evaluate their rhythmicity, stereotypedness or unpredictability, to find out in which poses they are most pronounced, with what other neurological symptoms are combined. When collecting anamnesis in patients with involuntary movements, it is necessary to find out the presence of hyperkinesis in other family members, the effect of alcohol on the intensity of hyperkinesis (this only matters with respect to tremor), drugs used earlier or at the time of examination.

• Tremor is a rhythmic or partially rhythmic trembling of a part of the body. Most often, tremors are observed in the hands (in the hands), but it can occur in any part of the body (head, lips, chin, trunk, etc.); a tremor of the vocal cords is possible. Tremor arises from the alternative reduction of opposing agonists and antagonists.

Types of tremor distinguish by localization, amplitude, conditions of occurrence.

• A low-frequency slow rest tremor (arising in a resting limb and diminishing / disappearing under arbitrary movement) is typical of Parkinson's disease. Tremor usually occurs on one side, but later becomes bilateral. The most typical (though not obligatory) movements are the "roll-over", "counting of coins", amplitude and localization of muscle contractions. Therefore, when characterizing clinical forms, local and generalized isolates are distinguished; one- or two-sided; synchronous and non-synchronous; rhythmic and irregular rhythmical myoclonias. To family degenerative diseases, in the clinical picture of which myoclonias are the main symptom , include Davidenkov's family myoclonia, Tkachev's family localized myoclonia, Lenoble-Obino family nystagmus myoclonia, Friedreich's multiple paramyoclonus. As a special local form of myoclonia, rhythmic myoclonus (myorhythmia) is distinguished, differing in stereotypedness and rhythmicity. Hyperkinesis is limited to the involvement of the soft palate (velopalatinny myoclonia, velopalatinny "nystagmus"), individual muscles of the tongue, neck, less often the extremities. Symptomatic forms of myoclonus occur with neuroinfections and dysmetabolic and toxic encephalopathies.
• Asterixis (sometimes called "negative myoclonus") - sudden irregular "fluttering" vibrational movements of the limbs in the wrist or, rarely, in the ankles. Asterixis is due to the variability of the postural tone and the short-term atony of the muscles that hold the pose. More often it is two-sided, but it arises on both sides asynchronously. Asterixis most often occurs with metabolic (renal, hepatic ) encephalopathy, also possible with hepatocerebral dystrophy.
• Tiki is a rapid repetitive non-rhythmical, but stereotyped movement in separate muscle groups, resulting from the simultaneous activation of agonist muscles and antagonists. The movements are coordinated, similar to a caricatured mapping of a normal motor act. Any attempt to suppress them with willpower leads to an increase in tension and anxiety (although you can arbitrarily suppress the tick). Making the desired motor reaction gives relief. It is possible to simulate a tick. Ticks intensify with emotional stimuli (anxiety, fear), but decrease with concentration of attention, after drinking alcohol, during pleasant entertainments. Tics can appear in different parts of the body or be limited to one part of it. The structure of hyperkinesis is distinguished by simple and complex tics, localization - focal (in the muscles of the face, head, limbs, trunk) and generalized. Generalized complex tics can in appearance outwardly resemble a purposeful motor act. Sometimes the movements resemble myoclonus or chorea, but, unlike them, tics less make it difficult to perform normal movements in the affected part of the body. In addition to motor, distinguish and phonetic tics: simple - with elementary vocalization - and complex, when the patient screams whole words, sometimes swear words (coprolalia). The frequency of localization of tics decreases in the direction from the head to the legs. The most common tick is blinking. Generalized tic or Gilles de la Tourette's disease is a hereditary disease transmitted by an autosomal dominant type. Most often begins at the age of 7-10 years. It is characterized by a combination of generalized motor and phonetic tics (screaming, coprolights, etc.), as well as psychomotor (obsessive stereotypical actions), emotional (suspiciousness, anxiety, fear) and personal (seclusion, shyness, self-doubt) changes.
• Dystonic hyperkinesis - involuntary prolonged violent movements, which can cover muscle groups of all sizes. They are slow, constant or arising periodically during specific motor acts; distort the normal position of the limb, head and trunk in the form of certain poses. In severe cases, fixed postures and secondary contractures may occur. Dystonia is focal or involves the whole body (torsion dystonia). The most frequent variants of focal muscular dystonia are blepharospasm (involuntary closing / squinting of the eyes); oromandibular dystonia (involuntary movements and spasms of the muscles of the face and tongue); spasmodic torticollis (tonic, clonic or tonic-clonic contraction of the neck muscles, resulting in involuntary tilts and turns of the head); writing spasm.
• Athetosis is a slow dystonic hyperkinesis, the "crawling" spread of which in the distal sections of the limbs gives involuntary movements vermicular, and in the proximal parts of the limbs - snake-like character. Movement involuntary, slow, arise mainly in the fingers and toes, the tongue and change each other in a random sequence. The movements are smooth and slower than the trochaic ones. Poses are not fixed, but gradually pass one into another ("mobile spasm"). In more pronounced cases, proximal muscles of the extremities, neck muscles and face are also involved in hyperkinesis. Athetosis increases with arbitrary movements and emotional tension, decreases in certain poses (in particular, on the stomach), in a dream. Unilateral or bilateral athetosis in adults may occur in hereditary diseases with extrapyramidal nervous system damage ( Huntington's chorea, hepatocerebral dystrophy); with vascular lesions of the brain. In children, athetosis often develops as a result of brain damage in the perinatal period as a result of intrauterine infections, birth trauma, hypoxia, fetal asphyxia, hemorrhage, intoxication, hemolytic disease.