Myasthenia Gravis - Causes, Symptoms And Treatment

2024 Author: Josephine Shorter | [email protected]. Last modified: 2024-01-07 17:49

Myasthenia gravis: forms, symptoms and treatment

Myasthenia gravis is a chronic condition in which muscles are affected. The main manifestation of pathology is their rapid fatigue. The peculiarity of the disease is its constant progression. The cause of myasthenia gravis lies in the disorder of the neuromuscular connections.

In addition to increased muscle fatigue, a person's muscle weakness increases, which negatively affects the volume of actions performed.

Myasthenia gravis is accompanied by myasthenic crises, which can end in the death of a person. Modern medicine can reduce the number of deaths from this pathology. Thanks to complex therapy, it is possible to achieve a stable remission of the disease.

Content:

• What is myasthenia gravis?
• Causes of myasthenia gravis
• Myasthenia gravis classification
• Myasthenia gravis symptoms
• Myasthenic crisis
• Diagnosis of myasthenia gravis
• Treatment of myasthenia gravis
• What drugs are contraindicated
• Prevention of myasthenia gravis
• Forecast

What is myasthenia gravis?

Myasthenia gravis is an autoimmune disease that affects receptors that communicate between muscles and the nervous system. The immune system begins to attack the body's own cells, which are completely healthy. This can lead to impaired swallowing movements, uncharacteristic weakness of the respiratory system, as well as other equally severe disorders. As the pathology progresses, the muscles of the lips, face, pharynx, tongue, neck, eyes, and the whole body atrophy in the patient.

The medical term for myasthenia gravis is "myasthenia gravis pseudoparalytica". Translated into Russian, this means asthenic bulbar paralysis. Russian doctors often use the term “myasthenia gravis”.

The disease boils down to the fact that a nerve impulse is transmitted from the brain to the muscles with disorders. This is due to a malfunction in the metabolism of acetylcholine in the body.

Skeletal muscles are responsible for the movement of human limbs. The work of internal organs and blood vessels is provided by smooth muscles. Motor nerves will be used to move the skeletal muscles. At the point where the nerve connects to the muscle, an electrical impulse occurs. Acetylcholine is required for its transmission. This is a special substance that gets from the nerve into the gap between it and the muscle, providing an electrical discharge. Due to it, the muscle contracts.

When a person develops myasthenia gravis, the synthesis and release of acetylcholine is disrupted. Therefore, the impulse will pass to the muscle with a malfunction. Each time, the conductivity gets worse. Therefore, human movements are affected. In the terminal stages of the disease, the patient is completely immobilized.

Often, myasthenia gravis develops against the background of a tumor of the thymus gland, as well as with hyperplasia. Sometimes, patients are diagnosed with organic lesions of the nervous system, breast tumors, lung tumors, ovarian or prostate cancer.

Causes of myasthenia gravis

To date, the reasons for the development of the disease are unknown to science. Doctors can only name the risk factors that increase the likelihood of myasthenia gravis.

These include:

• Hormonal imbalance.
• Chronic stress.
• Taking certain medications that affect the work of the muscle-nerve synapse.
• Infectious diseases.
• Cancer of the lungs, breast and other organs. A tumor growing in the body makes the thymus work at its peak, and also provokes glandular hyperplasia.

Myasthenia gravis is not inherited, but the predisposition to the development of the disease in such families is higher. Relationships such as "mother-daughter" and "sister-sister" are often observed.

Myasthenia gravis classification

Myasthenia gravis, depending on the nature of its occurrence, can be of two forms:

• Congenital disease. It is caused by a gene mutation that occurs even during the intrauterine development of the child. The first signs of the disease appear immediately after the baby is born. Respiratory function suffers, which often becomes the cause of the death of the baby.
• Acquired disease. In most cases, people are diagnosed with acquired myasthenia gravis, which develops throughout life.

Depending on the person's age, myasthenia gravis is divided into adult and children's.

In children, three forms of the disease are distinguished:

• Neonatal myasthenia gravis, which is passed from mother to child.
• Early childhood myasthenia gravis, which manifests at the age of 3-5 years.
• Myasthenia gravis is juvenile, which develops at the age of 12-17 years.

Depending on which muscles were affected, the following forms of the disease are distinguished:

• Local myasthenia gravis. Certain muscle groups are affected. The muscles of the face are often affected.
• Generalized myasthenia gravis. In this case, various muscles of the body will be affected. This form of pathology progresses rapidly and has a severe course.

Local myasthenia gravis can transform into generalized. Some patients immediately develop multiple muscle lesions. Such a pathology is difficult to correct and often ends in the death of a person.

Depending on which muscle groups were affected by local myasthenia gravis, the following forms are distinguished:

• Skeletal muscle myasthenia gravis. The muscles of the limbs are affected.
• Myasthenia gravis of the eyes and eyelids. The organs of vision suffer, it begins to fall. The patient's upper eyelid drops. Over time, the patient develops myopia.
• Myasthenia gravis of the pharynx and face. It is difficult for a person to swallow food, his speech suffers, his voice changes to a nasal one.

There are diseases that, in their clinical course, resemble myasthenia gravis, but the causes of their occurrence will be different. Such pathologies are called myasthenic syndromes. More than the rest, myasthenia gravis resembles Lambert-Eaton syndrome. With this disease, limbs are more often affected, deep tendon reflexes are disturbed, but the organs of vision are not involved in the pathological process.

Depending on the nature of the course of myasthenia gravis, the following types are distinguished:

• Myasthenic crises, which are accompanied by impaired motor activity. After their completion, the symptoms of the disease regress.
• Myasthenic condition. This is a classic myasthenia gravis that progresses over several years.
• Progressive myasthenia gravis. The disease progresses all the time, but doctors regard it as a relatively benign type of pathology.
• Malignant form. Pathology develops quickly, muscle performance is severely impaired.

Myasthenic crises are the most dangerous conditions for human life.

Myasthenia gravis symptoms

The symptoms of myasthenia gravis can be distinguished as follows:

• Muscle weakness, uncharacteristic for a healthy person.
• Dysfunction of the eye, facial, chewing and bulbar muscles, muscles of the legs and arms.
• Split eyes.
• Ophthalmoparesis.
• Strabismus.
• Ptosis.
• Difficulty swallowing food.
• Loss of voice, impaired articulation, change in voice.
• Gait disorder.
• Increased sleepiness, fatigue.
• Muscle pain.

As the pathology progresses, they will become more pronounced. Over time, a person develops myasthenic crises. They are accompanied by fainting and acute oxygen starvation of the brain.

Myasthenic crisis

Over time, the person will feel worse and worse. A severe form of the disease will lead to the fact that he will begin to develop myasthenic crises. This condition is understood as a sharp deterioration in well-being. The crisis develops due to acute muscle weakness.

At first, a person's breathing quickens, and then decreases and becomes intermittent. The face will turn purple. The pulse accelerates, blood pressure rises to 200 mm Hg. Art.

When breathing stops, the person loses consciousness. If at this time he is not provided with medical assistance, then he will die.

Diagnosis of myasthenia gravis

Diagnostic measures aimed at detecting myasthenia gravis:

• Taking anamnesis:
• The doctor specifies how long ago the person had disturbing symptoms: muscle weakness, double vision, drooping of the upper eyelid.
• The doctor finds out if there were cases of myasthenia gravis or other autoimmune diseases in the family. In this regard, the danger is rheumatoid arthritis, etc. It is also necessary to clarify whether someone in the family has had cancer.

In addition, the diagnosis of myasthenia gravis includes:

• Neurological examination. The doctor conducts tests with repetitive movements. The weakness in a person with myasthenia gravis will increase.
• Proserine test. The physician evaluates the patient's muscle strength. Then he is given an injection of proserin (this drug enhances the nerve impulse supplied to the muscles). The doctor then measures the patient's muscle strength again. If he develops myasthenia gravis, then it rises.
• Determination of antibodies in the blood. The analysis will show the presence of proteins that are produced against the acetylcholine receptors. Most often they circulate in the blood, but their absence is not evidence of a refutation of the diagnosis.
• Electroneuromyography. This diagnostic procedure evaluates muscle excitability and nerve impulse conduction. Myasthenia gravis is accompanied by normal impulse transmission, but the muscles do not give the desired response to it. With prolonged stimulation of muscles with electric current, the doctor reveals the phenomenon of post-tetanic exhaustion.
• CT and MRI of the anterior mediastinum. These studies provide information about the condition of the chest wall. They allow you to identify a tumor of the thymus gland, which is often combined with myasthenia gravis.

Treatment of myasthenia gravis

Treatment of myasthenia gravis is implemented in 2 lines: you need to direct efforts to relieve pathological symptoms and act on the cause of the disease. To relieve the symptoms of the disease, the patient is prescribed anticholinesterase drugs: Proserin, Kalimin, Oxazil, etc. Treatment begins with minimum dosages. In the future, the doctor increases them, bringing them to optimal values for a particular patient. To reduce the amount of antibodies in the blood, the patient is prescribed corticosteroids and immunosuppressants.

Medicines used to combat myasthenia gravis:

• Potassium preparations: Kalimin 60N, Potassium chloride, potassium-normin. Their use makes it possible to increase muscle contractility and improve the conduction of a nerve impulse to them.
• Anticholinesterase agents: Kalimin, Proserin, Oxazil, Galantamine. These drugs are aimed at arresting the action of cholinesterases. This enzyme helps break down acetylcholine. The latter begins to accumulate in the gap between the muscles and nerve fibers, so the muscles respond better to impulses sent by the nervous system. The listed drugs form the basis of myasthenia gravis therapy.
• Glucocorticosteroids: Prednisolone, Dexamethasone. These medicines reduce the intensity of the autoimmune response, so the number of antibodies that attack the acetylcholine receptors is reduced.
• Immunosuppressants: Azathioprine, Cyclosporine. These drugs suppress the immune system. A decrease in its activity allows you to slow down the progression of myasthenia gravis. However, the pathological effect of drugs on the body's own defenses negatively affects health in general.
• Human immunoglobulin. It is taken from healthy people and administered to patients with myasthenia gravis. This treatment affects the immune system, reducing the intensity of the body's autoimmune response.
• Antioxidants: Actovegin, Cerebrolysin. These drugs normalize metabolism in the body, increase tissue nutrition.

Other treatments for myasthenia gravis include:

• Plasmapheresis, which mechanically cleans the blood from antibodies. Several portions of blood are taken from the patient and passed through a centrifuge. Blood cells are retained and antibodies are removed from it. Then a person's own blood is diluted with rheopolyglucin and returned to the patient's bloodstream through a vein.
• Surgery to remove the thymus gland. This procedure allows you to cope with actively progressive myasthenia gravis against the background of a tumor of the thymus with a violation of the process of swallowing food.
• Irradiation of the thymus with gamma rays. This procedure allows you to reduce the intensity of the inflammatory process.
• Extracorporeal immunopharmacotherapy. Patients release lymphocytes from the blood, which are treated with drugs and returned to the human body. This procedure allows you to achieve a stable remission of the disease for a year.
• Undergoing treatment in sanatoriums.

A person with myasthenia gravis should tune in to lifelong medication. They are prescribed in courses, during which the patient must be under the supervision of a doctor. You need to measure your blood pressure every day. It is important to know your blood glucose values. At the same time, osteoporosis prevention is carried out. When the disease worsens and it is not possible to cope with it by taking medications, plasmapheresis is shown to a person. The procedure is carried out up to 7 times a day.

If a patient has a crisis, then he is resuscitated and connected to a ventilator. Plasmapheresis is carried out in parallel. To purify the blood from antibodies, the patient is prescribed cryopheresis, cascade plasma filtration, and immunopharmacotherapy. Such therapeutic measures allow you to cope with myasthenia gravis for up to a year.

What drugs are contraindicated

Patients with myasthenia gravis are not prescribed the following antimicrobial drugs:

• Means of the aminoglycoside series: Netilmicin, Gentamicin, Streptomycin, Kanamycin, Monomycin, Tobramycin, Sizomycin, Amikacin.
• Morolides: Erythromycin, Doxycycline, Tetracycline and Azithromycin.
• Fluoroquinolones: Enoxacin, Ciprofloxacin, Ofloxacin, Norfloxacin, Lomefloxacin, Fleroxacin, Sparfloxacin.
• Malaria drugs: quinines and chloroquinines.
• Uroseptics: Palin.

Drugs for the relief of seizures (Phenytoin and Carbamazepine), as well as neuroplegics (Sulpiride, Clozapine, Phenothiazines) are prohibited.

Do not prescribe drugs that affect the cardiovascular system to patients with myasthenia gravis:

• All beta-blockers, including Timolol eye drops.
• Alpha and beta blockers: Labetalol.
• Calcium channel blockers: Verapamil, Nifedipine.
• First class antiarrhythmics: Procainamide and Quinidine.

Saluretics are prohibited, namely: Furosemide and hypothiazides. However, Veroshpiron and other spironolactones can be used for treatment.

Neuromuscular blockers are contraindicated:

• Muscle relaxants (Relanium) and non-depolarizing muscle relaxants (Arduan and Tubocurarine).
• Centrally acting muscle relaxants with long-term effects: Baclofen and benzodiazepines.
• Local pain relievers: Lidocaine.
• Botulinum toxin.

Other prohibited drugs include:

• Cuprenil.
• Alpha interferon.
• Magnesium preparations: magnesium sulfate, Panangin, Asparkam.
• Preparations containing iodine-based radiocontrast agents.
• Timazole, statins, and gabapentin are used with caution.

Prevention of myasthenia gravis

All people with diagnosed myasthenia gravis should be registered with a neurologist, constantly monitor the level of blood pressure and glucose.

There is no specific prevention of the disease.

Doctors are limited to only the following recommendations:

• Do not engage in heavy physical work.
• Exclude pronounced physical activity in everyday life.
• Do not be too active in sports.
• The menu should include vegetables, fruits and dairy products.
• It is important to give up a long time in the sun, be sure to wear sunglasses.
• Vitamin complexes should be taken.
• It is forbidden to take magnesium preparations, antipsychotics, antibiotics and diuretics.

Forecast

In the past 30 years, doctors have made significant progress in treating myasthenia gravis. Thanks to therapy, mortality among these patients has significantly decreased. This became possible largely thanks to the use of immunomodulatory therapy. Its implementation improves the forecast.

Remissions in myasthenia gravis are followed by periods of exacerbation. There is no way to completely cope with the disease. However, an integrated approach to therapy can prevent muscle atrophy and exclude death. If a person ignores regular supervision by a neurologist, then myasthenia gravis will continue to progress and lead to cardiac arrest or other serious complications. Under such conditions, the risk of death of the patient is extremely high.

Women in position should be under special control. During pregnancy, the frequency of exacerbations increases.

The uniform recommendation for all patients is constant health monitoring. Thus, it will be possible to minimize the symptoms of myasthenia gravis.

The prognosis for myasthenia gravis is the better, the earlier the disease is detected and treatment is started.

The generalized form of the disease is worse than the rest. Ocular myasthenia gravis most often ends well. If there is no treatment, the person will eventually have a crisis. It leads to disruption in the work of all internal organs.

Article author: Mochalov Pavel Alexandrovich | d. m. n. therapist

Education: Moscow Medical Institute. IM Sechenov, specialty - "General Medicine" in 1991, in 1993 "Occupational Diseases", in 1996 "Therapy".