Myopathies — group of diseases which basis is made by various violations in metabolism and a structure of muscular tissue leading to decrease in force of the affected muscles and restriction of physical activity. Typical lines of a myopathy are: the progressing muscular weakness, development of muscular atrophies, decrease in tendinous reflexes and a tone of muscles. Electrophysiological researches, biochemical blood tests and urine, results of the molecular and genetic and histochemical analysis of the samples received by a biopsy of muscles help to establish the diagnosis of a myopathy. Treatment assumes complex purpose of metabolic medicines courses 3 times a year.
Myopathies concern to group of neuromuscular diseases. Are characterized by dystrophic defeat of muscular tissue (mainly skeletal muscles) with a selective atrophy of separate fibers () at full functional safety of animalny nervous system. Differ in the chronic steadily progressing current. As a rule, the demonstration of clinical manifestations of a myopathy is the share of children's and youthful age. The most part of cases is represented by genetic pathology - it is so-called primary myopathies. Less often myopathies of the acquired genesis — secondary or symptomatic meet.
Etiology and pathogenesis of myopathies
Genetically determined violations in functioning of mitochondrions and ion channels , in synthesis of the muscle proteins or enzymes regulating a metabolism of muscular tissue are the cornerstone of primary myopathies. Inheritance of a defective gene can happen retsessivno, is prepotent and linked to the H-chromosome. At the same time external factors often act as the triggers starting development of a disease. Various infections (chronic tonsillitis, frequent SARS, bacterial pneumonia, salmonellosis, pyelonephritis and so forth), alimentary dystrophy, severe injuries (a fracture of bones of a basin, a polytrauma, ChMT, etc.), a physical overstrain, intoxications can be similar "starting" factors.
The acquired myopathies can develop against the background of endocrine frustration (a giperparatireoz, Itsenko-Cushing's disease, a hypothyroidism, a gipertireoz, a giperaldosteronizm), chronic intoxications (toxicomania, drug addiction, alcoholism, professional vrednost), malabsorption and avitaminosis, a serious chronic illness (HPN, a chronic liver failure, heart failure, HOBL), tumoral processes.
Existence of genetically determined or acquired defects of the metabolites participating in a metabolism and creation of muscle fibers leads to emergence and progressing of degenerate changes of the last. The atrophy develops, there is their replacement with fatty and connecting tissue. Muscles lose ability to reduction that causes muscular weakness and restriction of an opportunity to carry out the active movements.
The last researches revealed at patients with various forms of myopathies of violation of functioning as central (at the dientsefalny level), and the peripheral departments of the autonomic nervous system playing not the last role in pathogenesis of a disease. These can explain primary defeat of proximal departments of extremities, typical for the myopathies, having richer vegetative innervation.
Classification of myopathies
Experts in the field of neurology developed several classifications of myopathies. The greatest popularity among clinical physicians was received by the etiopatogenetichesky principle of division according to which allocate hereditary, inflammatory, metabolic, membrane, paraneoplastic and toxic myopathies. Among hereditary myopathies 3 look are most widespread: a juvenile/youthful form of Erba, a pseudo-hypertrophic form of Dyushen and a shoulder - a scapular and front form. Meet skapuloperonealny, okulofaringealny, disteel, etc. forms less often. Congenital myopathies go separate group: disease of the central core, not crimson and miotubulyarny myopathy, disproportion of types .
Inflammatory myopathies are classified as infectious - arising owing to infectious and inflammatory defeat of muscular tissue at various infectious processes: bacterial (a streptococcal infection), virus (enteroviruses, flu, a rubella, HIV), parasitic (trichinosis, toxoplasmosis) and idiopathic — dermatomiozit, miozit with inclusions, polimiozit, myopathies at Shegren's syndrome, hard currency, a sklerodermiya, etc. collagenases.
Metabolic myopathies are subdivided on connected with violation of lipidic exchange in muscles (insufficiency atsetil-KOA-degidrogenazy, deficiency of a carnitine), exchange of a glycogen (Andersen's disease, a disease to the Pomp, the III type, Mac-Ardl's disease, deficiency of a kinase of a fosforilaza of b, deficiency of a fosfoglitseromutaza), metabolism of purin (deficiency of MADA enzyme) and mitochondrial myopathies (deficiency of reductase, ATP, cytochrome b, b1).
Symptoms of myopathies
The majority of myopathies have the gradual beginning from emergence of small muscular weakness in extremities, the fatigue more quickly arising from walking and other physical activity. Within several years there is a weakness increase, muscular atrophies appear and progress, there are deformations of extremities. Because of considerable muscular weakness patients hardly rise from a floor and go on a ladder, cannot jump and run. To rise from a chair, they should use special receptions. The type of the patient is characteristic: krylovidno remote shovels, the lowered shoulders, the stomach which is stuck out forward and strengthened lumbar . "Duck" gait is observed — the patient moves, being shaken in the parties.
Pathological changes at myopathies happen symmetrically in muscles of extremities and trunks. As a rule, muscular atrophies are observed in proximal departments of hands and legs. In this regard muscles of disteel departments of extremities can look hypertrophied. Such miopatichesky pseudo-hypertrophy is most noticeable in muscles of shins. Along with increase of muscular weakness gradual fading of tendinous reflexes and the progressing decrease in a muscular tone is observed, i.e. peripheral sluggish paralysis develops and aggravated. Over time contractures of joints become result of sharp restriction of active movements.
Myopathies can be followed by damage of mimic muscles that is shown by impossibility to extend lips a tubule, to whistle, frown a forehead or to smile. Damage of a circular muscle of a mouth leads to emergence of the dizartriya connected with difficulty of a pronunciation of vowels.
The clinic of some myopathies includes the damage of respiratory muscles leading to developing of stagnant pneumonia and development of respiratory insufficiency. Pathological changes of a cardiac muscle with emergence of a cardiomyopathy and heart failure, muscles of a throat and throat with development of a dysphagy and miopatichesky paresis of a throat are possible.
Features of separate forms of a myopathy
The juvenile myopathy of Erba is inherited autosomno-retsessivno. Pathological processes begin to be shown at the age of 20-30 years. First of all they cover muscles of a pelvic belt and hips, then quickly extend to other muscular groups. Involvement of facial muscles is not characteristic. The beginning of a myopathy at younger age leads to an early obezdvizhennost of patients. At development of a disease at advanced age its current less heavy: patients it is long keep ability to move.
The pseudo-hypertrophic myopathy of Dyushen is inherited retsessivno is linked to a floor. Boys are ill only. As a rule, demonstrates within the first 3 years of life, is more rare — during from 5 to 10 years. Typically began with atrophic changes of muscles of a pelvic belt and proximal departments of the legs which are followed by a pseudo-hypertrophy of gastrocnemius muscles. Early there are contractures and a curvature of a backbone (, scoliosis, ). It can be observed mental retardation. The disease proceeds with damage of respiratory muscles and hearts (the cardiomyopathy is noted at 90% of patients with Dyushen's myopathy) that is the reason of an early lethal outcome.
Shoulder - a scapular and front myopathy of Landuzi – Dezherina has autosomno-prepotent inheritance. Demonstrates in 10-20 years from damage of mimic muscles. Gradually weakness and atrophies cover muscles of nadplechiya, shoulders and a breast. Muscles of a pelvic belt usually do not suffer. The slow current with long safety of working capacity, without life expectancy reduction is characteristic.
Skapuloperonealny myopathy — an autosomno-prepotent disease. Its feature is development of atrophies in muscles of disteel departments of legs and proximal departments of hands, and also existence of easy touch violations of disteel departments of both the lower, and top extremities.
The Okulofaringealny myopathy is characterized by a combination of damage of glazodvigatelny muscles to weakness of muscles of language and a throat. Usually demonstrates a bilateral ptoz, then disorders of swallowing join. Feature of this myopathy is its late beginning — on the 4-6th decade of life.
The disteel late myopathy is inherited autosomno-is prepotent. Differs in development of weakness and atrophies in disteel departments of extremities: in the beginning in feet and brushes, and then in shins and forearms. The slow current is characteristic.
Features of clinical manifestations of various forms of congenital, hereditary and metabolic myopathies are described in independent reviews.
Diagnostics of myopathies
Electrophysiological methods of inspection help to establish the diagnosis of a myopathy to the neurologist: elektroneyrografiya (ENG) and electromyography (EMG). They allow to exclude damage of a peripheral motor neuron and, thus, to differentiate a myopathy from an infectious miyelopatiya, violations of spinal blood circulation, a miyelit and tumors of a spinal cord. Data of EMG speak about changes of muscular potentials, characteristic of myopathies, - reduction of their amplitude and reduction of duration. The progressing process is demonstrated by existence of a large number of short peaks.
Biochemical blood test at a myopathy shows increase in contents aldomanholes, KFK, ALT, nuclear heating plant, LDG, etc. enzymes. In the biochemical analysis of urine increase in concentration of creatinine is indicative. In establishment paramount value the biopsy of muscles has the myopathy forms. The morphological research of samples of muscular tissue reveals existence randomly scattered atrophied among almost safe and hypertrophied muscle fibers, and also replacement of sites of muscular tissue on connecting or fatty. Statement of the final diagnosis is possible only after comparison of results of histochemical, immunobiochemical and molecular and genetic researches.
For the purpose of diagnostics of damages of a cardiac muscle to the patient with a myopathy consultation of the cardiologist, the ECG, ultrasonography of heart can be appointed; at suspicion on developing of pneumonia — consultation of the pulmonologist and a X-ray analysis of lungs.
Treatment of myopathies
Now pathogenetic treatment of myopathies is in a condition of scientific experiments in the field of genetic engineering. In clinical practice the symptomatic therapy consisting generally in improvement of metabolism of muscular tissue is applied. For this purpose apply vitamins E, B1, B6, B12, ATP, , amino acids (glyutaminovy acid, a hydrolyzate from a brain of a pig), antikholinesterazny medicines (ambenoniya, ), anabolic steroids (a nandrolona , ), medicines of potassium and calcium, . Combinations from several medicines appoint a course of 1-1,5 months 3 times a year.
Drug treatment of myopathies is supplemented with physical therapy (an electrophoresis with neostigminy, with calcium, ultrasound), light massage and LFK. Carrying out LFK can be carried out in the pool. The set of exercises has to be picked up so that to avoid an overload of the weakened muscles. In certain cases patients need consultation of the orthopedist and selection of means of orthopedic correction (corsets, footwear).
The basis of treatment of the acquired forms of myopathies is made by therapy of the main disease: correction of endocrine violations, elimination of toxic influence and desintoxication of an organism, elimination of infectious process, transfer of a chronic disease to a stage of steady remission etc.
Forecast and prevention of myopathies
The hereditary myopathies which are shown at early children's age are most adverse in the predictive plan. For the rest the forecast depends on a form of a myopathy, an involvement into process warm and respiratory muscles. The forecast of secondary myopathies more favorable on condition of successful treatment of the main disease.
As prevention of primary myopathies serves careful collecting the family anamnesis and obligatory consultation at the geneticist of couples planning pregnancy. Prevention of secondary myopathies is the exception of toxic impacts on an organism, timely treatment of infectious and endocrine diseases, correction of metabolic violations.