Myasthenia gravis: treatment and prognosis

Myasthenia gravis is a chronic disease of an autoimmune nature, characterized by the development of steadily progressing weakness of various groups of striated muscles. It affects mostly young people - 20-30 years old, but also registered in children and in elderly patients. The majority of cases - about 65% - are women.

In the first part of the article on myasthenia gravis, we examined the causes, mechanism of development and symptoms of this disease. Here we will talk about the methods of diagnosis, the principles of treatment and the prognosis of myasthenia gravis. So, let's begin.

Diagnosis of myasthenia gravis

The doctor will suspect that the patient has a myasthenia gravis already at the stage of communicating with him and an objective examination. Typical complaints (muscle weakness and muscle fatigue, especially after physical exertion and in the evening hours, eyelid drooping, double vision, difficulty swallowing, chewing, breathing), data of a hereditary history (myasthenia suffered from someone from the blood relatives of the patient) and objective examination (strabismus, live tendon and periosteal reflexes against a background of muscle weakness) will force a specialist to think about this disease. Having determined with a preliminary diagnosis to confirm or disprove it, the patient will be assigned additional examinations in the following amount:

• tests for fatigue;
• pharmacological tests;
• determination of the presence of antibodies to acetylcholine receptors;
• electromyography;
• computer or magnetic resonance imaging of mediastinal organs.

Tests for muscle fatigue

To determine the degree of fatigue of a particular group of muscles, they should be given a load. Repeated squeezing-unclenching of the hands will cause weakness of the musculature of the forearm and more pronounced omission of the eyelid. Walking on toes or heels, deep squats will help to identify the weakness of the muscles of the lower extremities. When the head is raised for 60 seconds from the supine position, the pathological weakness of the neck muscles is revealed. In order to diagnose the appearance or growth of ptosis (omission of the eyelid), the patient looks at one point for one or two minutes - to the side or upwards. Thus, the oculomotor muscles are strained and their weakness develops. In the course of the patient's conversation with the doctor, the latter will pay attention to the violation of speech and nasal hue of the voice of his interlocutor.

Pharmacological tests

The essence of such a test is that the patient is injected with a drug that must improve neuromuscular conduction, and then look at the dynamics of the symptoms of the disease. If it is positive - that is, the symptoms of myasthenia regress - the diagnosis is considered confirmed and final. As a rule, for diagnosis of myasthenia gravis, a solution of prosirin 0.05% or calamine 0.05% is injected subcutaneously to the patient. Symptoms of the disease significantly decrease or even completely disappear 30-60 minutes after the injection, and after 2-3 hours return again.

Determination of antibodies to acetylcholine receptors

As we learned from the first part of the article, myasthenia gravis is an autoimmune disease in which the body synthesizes antibodies to the acetylcholine receptors of the postsynaptic membrane. In 9 out of 10 patients with generalized myasthenia gravis, such antibodies are found, in addition, in a third of patients antibodies to striated muscles are detected. In the case of myasthenia gravis combined with a thymus tumor, antibodies to the striated muscle are determined in 8-9 patients out of 10. Even if antibodies to the postsynaptic membrane receptors could not be detected, but antibodies to striated muscles were detected, the diagnosis of myasthenia gravis was considered reliable.

This method of investigation in the diagnosis of myasthenia gravis is very important, because it allows you to explore the potentials of the action of a particular muscle. More than 80% of people with generalized myasthenia gravis and 1 of 10 patients with ocular form of the disease have pathological muscle fatigue.

Computer and / or magnetic resonance imaging

These methods of research can be prescribed to a person for the purpose of examining the thymus gland, or thymus. They allow you to get an image of this organ and diagnose the tumor process or hyperplasia of it.

To differentiate myasthenia gravis follows from such diseases:

• trunk encephalitis;
• botulism;
• basal meningitis;
• tumor of the brainstem;
• polymyositis;
• myopathy (eye shape);
• disturbance of cerebral circulation in the vertebrobasilar system;
• myasthenic syndromes on the background of taking antibiotics of D-penicillamine, polymyxin or aminoglycosides.

Principles of myasthenia gravis treatment

The aims of treatment of this disease are:

• improving the transmission of nerve impulse to the muscles;
• suppression of the autoimmune process.

To achieve the first goal, anticholinesterase drugs are used:

• proserin;
• kalimine (pyridostigmine bromide);
• oxazyl.

The dose of the drug and the frequency of reception are determined individually, depending on the form of myasthenia and the features of its clinical course.

To minimize the risk of side effects from the above drugs, at the same time they are prescribed veroshpiron, potassium orotate and ephedrine.

To suppress the autoimmune process, glucocorticoids - prednisolone, methylprednisolone, dexamethasone and others - are used. The dose of these medicines is also selected individually. When the expected effect is achieved, that is, the symptoms of myasthenia regress, the dose of the hormone is gradually reduced with a therapeutic up to supporting, however completely it or him do not cancel, differently illness or disease will return again, moreover and with double force.

If the effect of taking glucocorticoids is absent or the patient is intolerant of these drugs, he is prescribed immunosuppressors: cyclophosphamide, azathioprine and others.These are very serious drugs, the dose of which is selected strictly individually, in a hospital. In the case of severe myasthenia, glucocorticoids and immunosuppressors are used in parallel.

Patients younger than 60 years who have a thymus tumor are diagnosed with surgical treatment in the volume of complete or partial removal of the thymus gland - thymectomy. After incomplete removal of the organ, in the case of the myasthenia eye, as well as the elderly, X-ray therapy is carried out according to the protocol.

Therapy of the myasthenic crisis

Myasthenic crisis with the development of respiratory failure is an indication for tracheostomy or intubation of the trachea and transfer of the patient to artificial ventilation (IVL). He is also given glucocorticoids in large doses, the duration of which depends on the dynamics of the clinical picture of the disease.

In addition, injected intravenously and intramuscularly with proserin.

Apply and plazmaferez (cleansing plasma of toxic substances, in this case from antibodies).

To maintain the normal water-electrolyte balance, prescribe infusion therapy - drip saline, Trisol, Disol, Acesol with others, and also solutions of vitamins.

Nutrition during the crisis patient gets through a nasogastric tube (the tube that goes through the nasal cavity in the stomach).

In case the patient received an excessively high dose of anticholinesterase drugs, the cholinergic crisis is very likely to develop in him, the signs of which are:

• salivation;
• pupil narrowing on both sides;
• increased volume of bronchi secretion;
• slowing the frequency of heart contractions;
• activation of intestinal peristalsis.

In this situation, the patient must cancel the anticholinesterase drug and enter intravenously or subcutaneously a 0.1% solution of atropine in a volume of 0.5 ml. If necessary, repeat the injection.

Forecast

Timely diagnosis and adequate therapy can introduce myasthenia into the stage of remission, but under the influence of unfavorable factors, when patients are violated the regimen of taking drugs, and sometimes, it would seem, without reason, nevertheless there are exacerbations. Myasthenic crises with acute respiratory failure often lead to death of patients.

Educational program in neurology. Theme "Myasthenia gravis."