Myasthenia gravis - Causes, symptoms and treatment. MF.

Myasthenia gravis is a chronic progressive disease with the presence of crises, characterized by pathological fatigue and muscle weakness.

First described in 1672 by Thomas Willis. Currently, the incidence of myasthenia gravis is growing 5-10 patients per 100 000 population.

Causes of myasthenia gravis

Myasthenia gravis is a genetic disease, but the gene level has not been studied enough. Great importance is attached to the mutation of the gene responsible for the work of neuromuscular synapses. Two mechanisms of the disease development were discovered:

• biochemical shifts in the region of the myoneural synapses, caused by a change in the function of the hypothalamus with secondary involvement of the thymus gland in the process;
• autoimmune lesion of the thymus gland with violation of neuromuscular transmission. This reduces the synthesis of acetylcholine and increases the activity of cholinesterase.

Stress, catarrhal diseases, impaired immune functions of the body can serve as a trigger factor, which leads to the formation of antibodies to own cells, against acetylcholine receptors of the postsynaptic membrane of neuromuscular junctions( synapses).Normally, these synapses transmit a pulse from the nerve to the muscle through biochemical reactions involving the mediator acetylcholine.

When excited, acetylcholine enters through the presynaptic membrane into the synaptic cleft to the cholinergic receptors of the postsynaptic membrane( muscular), causing its excitation. The enzyme acetylcholinesterase destroys the mediator, limiting its duration. With myasthenia, this complex mechanism is broken. At the ends of the synapses, little acetylcholine is produced, or it is intensively destroyed by cholinesterase, and as a result, this synapse is blocked and a nerve impulse is not possible.

Myasthenia gravis begins more often in 20 - 40 years. Women are more often ill than men( 2: 1).

Symptoms of myasthenia gravis

The main sign of myasthenia gravis is weakness and dramatically increased fatigue of skeletal muscles during work or prolonged exertion. The muscle weakness increases with repeated movements, especially at a fast pace. The muscle is as if "tired" and ceases to obey until complete paralysis. After rest, the function of the muscles is restored. In the morning, after a dream, the patient feels generally normal. Several hours of wakefulness lead to the growth of myasthenic symptoms.

There are three forms of myasthenia gravis:

• ophthalmic;
• bulbar;
• generalized.

The muscles that are innervated by the cranial nerves are the first to be affected most often. In the future, it is possible to defeat the muscles of the neck, to a lesser extent the muscles of the trunk and extremities. The first signs of the disease are the lower eyelid and dilation, which occur when the external muscles of the eyeball, the circular muscle of the eye, the muscle that lifts the upper eyelid are damaged. If in the morning the patient can open the eye completely and freely, then further blinking leads to a weakening of the muscle and the eyelid simply "hangs".It's an eye shape.

On a photo Ptosis at a masthenia

At a bulbar form the muscles innervated by bulbar group of nerves are amazed. In this case, there will be violations of swallowing, chewing. The speech will change - it will become quiet, hoarse, nasal, hoarse, the voice will quickly deplete right up to the silent speech.

With the most frequent, generalized form, the process begins with the oculomotor muscles and then all muscles are involved in it. The muscles of the neck and the facial muscles are the first to suffer. The patient struggles to hold his head. There is a peculiar face with a transverse smile and deep wrinkles on the forehead. Saliva appears. In the future, the weakness of the muscles of the limbs is added. The patient does not walk well, can not service himself. The condition is better in the mornings, worse by the evening. Each subsequent movement of the patient to perform is becoming increasingly difficult. Over time, the muscles atrophy. The proximal parts - shoulders, hips - are more affected.
Tendon reflexes are rapidly depleted and appear after rest.

In the photo Generalized form of myasthenia gravis

Myasthenia gravis examination

For electromyography, the myasthenic reaction is important, the pharmacological test is a significant improvement after the administration of anticholinesterase drugs( proserine 0.05% 1 ml IM) and an immunoassay - the determination of the antibody titer to acetylcholine receptors, as well as the detection of thymoma( tumorthymus gland) - computed tomography of the organs of the anterior mediastinum.

Myasthenic crisis

The course of myasthenia is progressing with the increase in symptoms and its severity. In severe form, patients develop myasthenic crises.

Myasthenic crisis is a sudden attack of severe weakness of the respiratory and pharyngeal muscles - a violation of breathing( frequent, wheezing), increased heart rate, drooling. Paralysis of the respiratory muscles during a severe crisis is a direct threat to the life of the patient.

Myasthenia gravis is a chronic serious disease, progressive, often leading to disability and requires careful monitoring and treatment.

Myasthenia gravis.

Myasthenic syndrome can be observed with lethargic encephalitis, bronchogenic carcinoma( lung tumor)( Lambert-Eaton syndrome), amyotrophic lateral sclerosis, thyrotoxicosis. There are a number of congenital myasthenic syndromes based on mutations of the genes of different subclinical acetylcholine receptors.

Treatment of myasthenia gravis

The main drugs for myasthenia gravis are anticholinesterase drugs - kalimine, proserin. The prescribed dosages and time of administration should be strictly observed because of the danger of overdose and the development of cholinergic intoxication - cholinergic crisis - convulsions, twitching, slowing of the pulse, narrowing of the pupils, salivation, pain, abdominal cramps. The antidote to this overdose is atropine penic acid or iv 0.5 - 1.0 ml.

Treatment with anticholinesterase drugs is carried out for years, regulating preparations depending on the severity of the disease: oxazil, proserine, kalimine, galantamine. To strengthen their action, potassium salts are used, for the delay of potassium in the body use spironolactone courses. In severe cases, hormone therapy and cytostatics are used.

Effective "pulsterapiya" - large doses of hormones( 1000 - 2000 mg prednisolone) with a further gradual decrease in dose. Immunosuppressants - azothioprine, cyclosporine, cyclophosphamide. If a diagnosis of thymoma is detected, surgical treatment is indicated.

In severe cases of the myasthenic crisis, artificial ventilation of the lungs, plasmapheresis, administration of immunoglobulins, intravenous intravenous prodrug, ephedrine p / k is carried out in the intensive care units.

Special diets are not required, but it is advisable to eat foods rich in potassium: dried apricots, raisins, potatoes.

If myasthenia gravis

was found The main institution for the study, diagnosis and treatment of myasthenia gravis and myasthenic syndromes is the Moscow Myasthenic Center, created on the basis of the department of neuromuscular pathology of the Institute of General Pathology and Pathophysiology of the Russian Academy of Medical Sciences in 1983.In Russia, medicines for the treatment of myasthenia are included in the federal preferential list and are released free of charge according to the prescription of the doctor: metopred, prednisolone, kalimine, neuromidine, veroshpiron, cyclophosphamide, aziotioprine.

Patients with myasthenia gravis should be seen with a neurologist, take prescribed treatment regularly and follow all recommendations. Under such conditions, long-term retention of work capacity and quality of life is possible.

Patients with myasthenia gravis can not sunbathe, physically hard to work, use magnesium preparations, muscle relaxants, neuroleptics and tranquilizers, diuretics( except veroshpirona), aminoglycosides( gentamicin, kanamycin, neomycin, streptomycin. ..), fluoroquinolines( norfloxacin, ofloxacin), tetracycline, quinine derivatives, D-penicillamine. All patients are given a doctor such a list and should always be carried with them in order not to accept an unacceptable drug.

Do not self-medicate, herbal. To a patient with myasthenia, no medicine should be given without consulting a doctor! Kurarepodobnye substances enhance myasthenic phenomena.

Sanatorium treatment in the hot season in the south is not shown. Recommended sanatorium treatment in sanatoria with a medical profile: treatment of nervous diseases( brain disease);sanatoriums: Alatyr( Mordovia), Anzhersky( Kemerovo region), Bakirovo( Tatarstan), Arshan( Republic of Buryatia), Barnaul( Altai Territory), Beshtau and Zori Stavropolye( Stavropol(the Krasnodar Territory), the Borodin sanatorium( Kostroma Region), Izumrudny( Primorsky Krai), sanatoriums of the Moscow Region and St. Petersburg and many other health resorts of Russia and other countriesCIS

Consultation of a doctor on the topic of myasthenia gravis

Question: Can I completely recover from myasthenia gravis?
Answer: No, but as a result of correct and long-term treatment, complete disappearance of symptoms and prolonged remission can be achieved

Question: Can the myasthenic crisis be caused by improper treatment?
Answer: may. Insufficient doses of anticholinergic drugs will be ineffective and possibly the development of the myasthenic crisis. Overdosing them will lead to a cholinergic crisis. These two crises require immediate hospitalization, possibly in the intensive care unit because of the threat of development of stopping breathing.

Question: with prolonged remission, can I sunbathe?
Answer: no. Staying in the sun can cause an exacerbation of myasthenia, even with many years of remission.

Question: is myasthenia transmitted by inheritance?
Answer: no.

Question: Is normal pregnancy and childbirth possible?
Answer: possible. Pregnancy should be planned, consult a doctor. Reception of cytostatics to pregnant women is contraindicated and it is better to decide the issue of transferring to other medicines in advance. Everything is decided individually. The legacy of the myasthenia gravis is not transmitted.

Doctor neurologist Kobzeva S.V.