Torsion dystonia

Torsional dystonia ( deforming muscle paging) is a disease with various manifestations and the nature of genetic disorders. Basically torsion dystonia is manifested involuntary contractions of muscles, changes in their tone and the formation of pathological postures. This pathology was first described in 1908. The incidence of torsion dystonia in the population is 1 case per 160 000 population. In some populations, the incidence of this disease is much higher, in particular among the Ashkenazi Jews it is 1 case per 15 000 - 23 000 population. The total prevalence of all dystonia, according to minimal estimates, is 40 cases per 100 000 population.

The immediate cause and mechanism of development of torsion dystonia is still not clear enough, although intensive molecular genetic studies of recent years have expanded the notion of this pathology. In the literature there is a description of autosomal dominant, autosomal recessive and X-linked forms of the disease.

The appearance of the first signs of the disease is more often in the 1-2 decade of life, although it can fluctuate widely( from 1 year to 70 years).Torsional dystonia begins gradually, with the involvement of any one group of muscles of the legs, hands, face, neck or trunk in the pathological process. At first, changes in the tone and posture are not permanent, are periodic in nature, then become longer and spread to other parts of the body.

In accordance with the current classification, the following forms of dystonia are distinguished:

1) focal. It includes the following signs: involuntary contraction of the circular eye muscle, leading to a permanent closure of the eyelids( blepharospasm), spasm of the muscles of the mouth, tongue, cheeks and chewing muscles( oromandibular dystonia), spasmodic torticollis, a violation of the function of writing due to spasm of the muscles of the hands with the preservation of other movementsspasm of the foot), spasm of the foot, disturbance of pronunciation of sounds and disturbance of swallowing as a result of spasm of the vocal muscles and muscles participating in the act of swallowing( spastic dysphonia and dysphagia);

2) segmental( two or more body regions are located adjacent to each other);

3) generalized( either the whole body or several adjacent body regions are involved);

4) hemidistonia( the arm and leg on one side are involved in the pathological process);

5) multifocal( characterized by a combination of two or more focal forms).

A definite relationship has been established between the age at which the first signs of torsion dystonia appear and the degree of progression and severity of the disease. The earlier signs of the disease appear, the faster it progresses with the development of severe generalized forms. Local forms are often only the initial stage of heavier-flowing generalized forms. However, in some individuals these forms of torsion dystonia remain isolated and stable throughout the course of the disease. This development of events is observed mainly at the late onset of the disease( 3-4 decades of life).

Characteristic for dystonia are the variability in the increase in the volume and number of involuntary movements and postures, depending on the position of the body, the emotional and functional state of a person. Involuntary movements disappear during sleep, amplify with emotional tension, attempted purposeful movement, standing, and also during walking. Under certain conditions, manifestations of impaired muscle tone significantly decrease. Prolonged frequent muscle contractions can lead to hypertrophy( increase) in muscles and the appearance of pain. Prolonged forced position of the foot or hand leads to thickening and appearance of cicatricial changes in muscles, to shortening( retraction) of muscles, dystrophic changes in joints, permanent decrease in muscle stretch and restriction of normal mobility in the joint( contracture).The disease is slowly progressing, although the rate of progression may vary among different people. Against the background of proper treatment, there is often a temporary or complete disappearance of torsion dystonia( remission).The duration of such a state can be different.

The diagnosis of torsion dystonia does not raise any doubts in case of presence of the following characteristic signs in a person:

1) repeated cases of the disease in the family;

2) appearance of the first signs of torsion dystonia in 1-2 years of life;

3) change in muscle tone and the appearance of characteristic involuntary movements;

4) absence of pathological changes on the part of all other organs and systems;

5) absence of structural changes in the brain, which is determined by the method of computer and magnetic resonance tomography of the head;

6) gradual development and progressive course of the disease;

7) positive results in DNA testing.

Treatment. For forms of the disease that occur with excessive increase in muscle tone, the following drugs are used: nakom, sinemet, madopar. These drugs are used for a long time in small doses. To reduce side effects, a combination of these drugs with selegilin( yumeksom) and bromocriptine( parlodel) is shown. In forms that occur with a large number of involuntary movements, it is advisable to use drugs such as haloperidol and tiaprid, clonazepam, carbamazepine( finlepsin), baclofen and sirdalud. In focal forms, the greatest effect was obtained with the use of the toxin of the microorganism, which causes the development of botulism( botox, dysport).These drugs are introduced into pathologically altered muscles and have a good effect for 2-4 months. If the drug is ineffective, surgical treatment is performed.