Athetosis

Description:

The athetosis (the Greek athetos — moving, changing) represents the extrapyramidal hyperkinesia which is characterized by the constant slow worm-shaped movements in distal departments of extremities, a neck, language, face muscles. These movements are caused by dynamic spasms of the corresponding muscular groups in this connection this hyperkinesia is called sometimes a mobile spasm (spasmus mobilis). On prevalence of a hyperkinesia allocate a hemiathetosis and a generalized athetosis.

The athetosis "in pure form" in clinical practice meets infrequently. At some diseases of a phase of a widespread atetoidny spasm happen rather short-term, reminding choreiform twitchings. In other cases the typical generalized choreic hyperkinesia is combined with atetoidny spasms in distal departments of extremities. In such situations when accurate identification of the motive drawing is complicated, the hyperkinesia is designated by the term a choreoathetosis. Sometimes the phase of an atetoidny spasm is prolonged, and the corresponding muscular groups long time remain in a condition of reduction; for designation of such hyperkinesia the term an ate-toidny allotopia is sometimes used. Thus, the athetosis can be considered as "intermediate" — between a chorea and dystonia — a kind of an extrapyramidal hyperkinesia.

Athetosis symptoms:

The athetosis can be unilateral or bilateral. The Atetoidny movements are observed most often in a hand and look as the continuous sequence of bending, extension, assignment, reduction, slow rotation of fingers and a brush, continuous alternation of various elaborate poses of a distal segment of an extremity. The muscle tone is variable: the tonic phase nonsynchronously is replaced by muscular relaxation. At the patient painful, wavy myotonia of language and the person, various tonic grimaces can be observed, there is inarticulate a speech. Any purposive movements or adverse emotional factors lead to strengthening of tonic muscular contractions. In a dream the hyperkinesia disappears and renews after awakening.

At patients with a double athetosis on the first year of life the diffusion hypomyotonia is noted: children cannot hold the head and a trunk, to control the movement of hands. Clear manifestation of violent movements is usually noted by the end of the first year i.e. when normal there is a fixing of the first difficult movement skills. The disease is shown by a generalized atetoidny, horeatetoidny or atetoidno-dystonic hyperkinesia. Involvement of orofatsialny muscles (violent grimaces, a language protrusion, disturbance of the speech and swallowing), extremities (especially distal departments), a neck and a trunk is typical. Extremities of the patient are captured by the constant dynamic muscular spasms leading to alternation flexion супинаторных and the extensive and pronator poses which are sharply amplifying at purposive movements.

If the child gains ability to go (usually with a big delay), then when walking elaborate poses of feet, chaotic tonic contractions of muscles of a pelvic and shoulder girdle, axial muscles, rotation of a neck and trunk are noted. Self-service is sharply complicated. At any expressiveness of hyperkinesias the violent movements disappear in a dream. Most of children with a double athetosis remain intelligently safe. When the disease is caused by a heavy hypoxia, more expressed clinical picture with development of mental retardation is observed; at a part of patients epileptic seizures, decrease in hearing, pyramidal and cerebellar symptoms can take place.

The double athetosis is characterized by not progressing, stationary current. Over the years the condition of the patient is stabilized, becomes possible certain limited compensation of motive defect with development of elementary movement skills. At the corresponding leaving the forecast concerning life expectancy favorable.

At MRT at patients with a double athetosis more than in 60% of cases the centers of the increased signal strength (in T2 mode) in the field of dorsal departments of a shell or ventral group of kernels of a thalamus come to light.

The true extrapyramidal athetosis should be distinguished from externally similar state called by a pseudo-athetosis. Psevodoatetoz develops at defeat of ways of deep sensitivity at any level — from back columns of a spinal cord to parietal bark. At such sensitive rasstoystvo of the patient loses ability to control postural installation of an extremity therefore at the fixed anti-gravitational poses it observes the slow "wandering" of fingers reminding the coiling movements at an atetoidny spasm. Characteristic distinctive features of a pseudo-athetosis are noticeable strengthening of psevdoatetoidny movements after switching off of visual control (closing of eyes), existence at the patient of disturbances of joint and muscular and two-dimensional and space feeling, lack of increase in a muscle tone.

Athetosis reasons:

Most often the athetosis is one of symptoms of widespread defeat basal ганглиев various etiology. It can be observed at a number of hereditary diseases of a nervous system — a hepatolenticular degeneration, a paroxysmal choreoathetosis, dentato-rubro-pallido-lyuisovoy atrophies, the torsion dystonia, Lesh's syndrome — Naykhana, diseases of Gentington, an ataxy teleangiectasia, mitochondrial entsefalomiopatiya, etc. These diseases in detail are considered in the corresponding heads of the management. In rare instances the athetosis can be also manifestation of inflammatory, autoimmune, traumatic, toxic, metabolic, tumoral damages of a brain.

Treatment of the Athetosis:

Possibilities of treatment of a double athetosis are very limited. For the purpose of correction of tonic spasms the central cholinolytics, neuroleptics and benzodiazepine drugs are usually used, sometimes some positive effect is noted at purpose of drugs of a levodopa. In the most hard cases stereotaxic operations on subcrustal gangliya (destruction of a ventrolateralny kernel of a visual hillock) can be applied to reduction of expressiveness of hyperkinesias, however at a double athetosis they are accompanied by high risk of development of psevodobulbarny frustration with aggravation of the available alalias and swallowing.