- 1 Classification
- 2 Etiology
- 3 Symptoms
- 4 Diagnostics
- 5 Treatment
- 6 Complications
- 7 Forecast
- 8 Prevention
Researchers identify two groups of myotonic syndromes:
Each group has its own additional classification of pathologies depending on the characteristics of manifestations, the time of development.
Diseases of this group are united by inheritance according to the dominant principle and are characterized by myotonic, vegetative-trophic and dystrophic syndrome. Their peculiarity is postponed relaxation after tension, growing muscle weakness and atrophy.
By the time of occurrence they say about congenital, juvenile, adult and late form. Congenital is manifested in a child immediately after birth. Juvenile – from year to adolescence. Adult – from 20 years to 40. Late develops on reaching the age of forty.
Depending on which gene is mutated, dystrophic myotonia of types I, II and III is isolated. The first is the pathology, which is a form that is transitional between myotonia and myopathy. A typical example is Rossolimo-Steinert-Courshman disease. The muscles of the extremities, respiratory organs, myocardium are affected. Already in childhood there are violations of the skeleton.
Pathologies of the second type are manifested in people of different ages – from 7 years to 60 years. There is a constraint of movement, accompanied by pain. As development progresses, weakness of the muscles of the limbs and hands is noted. Endocrine diseases develop.
The third type is characterized by weakness of the deep muscles of the limbs, the body. Atrophy of the muscular tissue of the neck and shoulders leads to a hanging head. The attention, thinking, memory is broken.
This type includes pathologies associated with changes in the genes of the sodium and chlorine channels. The main manifestation is weakness in the hands.
Myotonia of the sodium channel include potassium-dependent, congenital paramyotonia, and also hyperkalemic periodic paralysis with myotonia.
By the potassium-dependent type include pathology transmitted by recessive and dominant trait. This type of myotonia occurs in children from 5 years old, adults up to 55. It is characterized by spasms and muscle pain. Lower limbs are most affected.
Congenital paramyotonia is transmitted by a dominant trait. The provoking factor is cold. An important feature is the transient weakness of the muscles, which can last several days. Chewing and mimic muscles are predominantly affected.
Hyperkalemic periodic paralysis with myotonia manifests itself up to 10 years, it is inherited according to the dominant trait. Attacks of weakness occur after taking foods with a high content of potassium. Arise in the legs, spread to the body and hands. Such episodes last up to two hours.
Thomsen’s myotonia and Becker’s disease are attributed to the canalopathies of the chlorine channel. The first is spasm of the muscles of the fingers and chewing muscles. Manifested at an early age, in some cases, the condition stabilizes. In general, muscle tissue remains sufficiently developed.
Becker’s myotonia is found in children from 4 years to 18. It has a more severe course than Thomsen’s disease. It is characterized by muscle pain. Distal, mimic muscles, muscles of extremities are affected.
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All types of myotonia due to genetic disorders. In some cases, the provoking factor is autosomal dominant transmission, in others – autosomal recessive.
So, myotonia Thompson is inherited by the dominant principle, i.e. one of his parents passed the gene to the child. This group also includes Eilenburg’s congenital paramyotonia, Rossolimo-Steinert-Kurshman myotonia. By recessive type, Becker’s disease develops, it arises due to the transfer of the mutated gene by both parents. It is believed that pathologies of this type manifest themselves in early childhood and have a more severe course.
Mutated genes cause a violation of the permeability of cell membranes, changes in the ion channels of chlorine and sodium, mediator metabolism, which, ultimately, leads to disruption of muscle tissue.
The mechanism of development of different types of myotonia is one. The weakened muscular tissue due to the impact on it of certain factors comes to a strong tone. There is a condition called myotonic attack. It appears at the moment when a person tries to make a movement that requires the involvement of the affected muscle fibers.
The provoking factors can be stress, cold, strong emotions, prolonged immobility.
It is believed that in some situations the pathology is caused by blood relations.
A characteristic symptom of all myotonia is a fist symptom. It is characterized by the fact that, by clenching a fist, the patient cannot quickly unclench him. To do this, he will need to make some effort. With subsequent compression, the fist expands more easily. Stiffness increases only with Eilenberg’s myotonia.
Common difficulties in all forms of the disease occur when trying to open your mouth, get up from a chair, quickly open your eyes, which were previously closed.
The severity of symptoms allows you to select a mild, moderate and severe form of the disease. The latter is characteristic mainly for congenital diseases.
Myotonia Thompson and Becker
At the beginning of the development of the disease, painful spasms of the leg muscles occur. Further, the muscles of the face, throat, and tongue are affected. Symptoms may decrease with age. For some, they disappear altogether. They are replaced by paresis and atrophy of the muscle fibers of the head and neck. With a decrease in the masticatory muscles, the cheeks are retracted. Atrophy of the cervical fibers leads to the tilting of the head.
The muscles of the limbs are later affected. Their weakness increases, strength decreases.
Suffer cardiovascular system. There are episodes of arrhythmia, bradycardia, lowering blood pressure. Hair, teeth fall out, skin becomes very thin.
Dystrophic myotonia of Rossolimo-Steinert-Kurshman
The first symptoms appear at the age of 15–20 years, sometimes at 35. Muscle spasms, motor excitability appear, with the development of the disease these symptoms fade away, which cannot be said about the complex of myopathic symptoms. Atrophy of the muscular tissue of the face, neck, hands develops, tendon reflexes decrease. Less commonly, the muscles of the legs and temples are affected. Gradually, weakness increases, patients complain of fatigue.
Atrophy of the muscles of the larynx leads to impaired swallowing, hoarseness or loss of voice. In men, impotence develops, in women, the menstrual cycle is disturbed. Often there are violations of cardiovascular activity, leading to arrhythmias, bradycardia.
Many patients have a cataract. In a dream, apnea attacks are possible.
The main symptom is the inability to relax the muscles after their tension, spasms occur. They hit a person when he closes his eyes, closes his jaws or clenches his hands into a fist. In this case, the reverse movement for a long time can not be done.
In appearance, patients look like athletes. To the touch the muscles are solid, dense, but the strength is not in them.
Myotonia chondrodystrophic form
Patients are distinguished by short stature, congenital dislocation of the hip, bound mimicry, stiffness of the joints.
Congenital dystrophic myotonia
Pathology is characterized by a violation in the child of the heart rate, increased drowsiness, increased stiffness in the cold, endocrine pathologies.
Muscle relaxation is difficult at cold ambient temperatures or local effects. So, when using very cold foods, the spasm covers the pharynx and tongue. It is removed after warming.
With general hypothermia, the so-called “cold paralysis” occurs.
To determine the exact diagnosis, the patient is examined, tendon reflexes are checked, information about the development of the pathology is collected, and the following studies are appointed:
- Electromyography. The bioelectric impulses of various parts of the muscle tissue, characterizing the damage to the nervous system, are recorded. Predominantly electromyographic study.
- DNA diagnostics.
- Blood chemistry. Detected antibodies to potassium channels, elevated levels of creatine phosphokinase.
- Hormonal research. Conducted when detecting endocrine disorders.
- ECG. Appointed to control the occurrence and development of cardiovascular pathologies.
The main goal is the differential diagnosis of myotonia of one type from another.
Currently, only symptomatic treatment of myotonia is performed. There are no ways to completely stop the course of the disease.
Pheniotin, Difenin, Mexiletin are prescribed to reduce cramps and relax muscle tissue. In order to reduce the potassium content – diuretics. Suppress immune responses by administering immunoglobulin. If necessary, apply anabolic substances. Severe cases of pathology are treated with courses of glucocorticoids. Arrhythmia is removed Novokinamidom, Quinine.
Some patients are prescribed courses of drugs aimed at improving metabolism (Actovegin), nootropic drugs that can remove the effects of excessive motor stimulation (Pantogam).
Diet plays an important role in preventing the development of the disease and alleviating its symptoms. It is based on limiting the intake of foods containing potassium.
Physiotherapy is prescribed. The main method is electromyostimulation, aimed at stimulating the neuromuscular system using electrical impulses.
Recommended massage. It is conducted courses 2-3 times a year.
Several times a year, physical therapy with a physiotherapist. For the rest of the time, exercise is shown at home. It is recommended to swim in the pool. Physical activity helps to normalize muscle tone, restore muscle activity.
The danger for people suffering from myotonia, are the consequences of this pathology. Among them stands out apnea, pneumonia, heart disease, arrhythmia, reduced intelligence.
Mild forms of pathology do not lead to disability and death. In the case of the development of complications associated with heart disease, death from its arrest is possible.
Genetic conditioning of myotonia leaves no room for its prevention. The only possible measure is conducting a DNA examination before planning a pregnancy. It is recommended, first of all, to those whose relatives suffer from this pathology.
Myotonia is a group of heterogeneous diseases characterized by cramping after their exertion. Pathologies are progressive, but rarely lead to disability and death. Currently, treatment is aimed only at alleviating the severity of symptoms.
The following sources were used to prepare the article:
Latysheva V. Ya., Drivotinov B.V., Olizarovich M.V. // Neurology and Neurosurgery: studies. allowance – Minsk, Vysh. wk 2013
The authors’ team // Nervous diseases – “SpecLit”, 2011 (Textbook for secondary medical schools).
Gusev E. I., Konovalov A. N., Skvortsova V. I. // Neurology and Neurosurgery, ed. Konovalova A.N., Kozlova A.V. – 2014.