Autoimmune myasthenia gravis > Health and Wellness.

Myasthenia gravis (MG) is a neuromuscular disease that affects the transmission of the nervous impulse to the muscle. Only affect the voluntary muscles (which we can control), fluctuating muscle weakness and fatigue easily, that increase physical activity and improve with rest.
Described more than 300 years ago, it has been in recent decades when the investigation of this pathology is experiencing great progress. It is considered to be the most studied autoimmune disease and better understood. Do not know what causes it or how to cure it, but great physical, psychological and social impact that causes in people that suffer from it.
Myasthenia gravis is classified as rare disease. Chronic, courses of improvement and worsening outbreaks, it is progressive, crippling and often negligible. No spreads, is not hereditary, not painful and does not affect the sensitivity.
The MG is very heterogeneous, which makes your prognosis and treatment are different depending on the age of the patient, clinical form of the disease, alteration of the thymus, types of antibodies, and time evolution.

Causes and prevalence of myasthenia gravis

We know that myasthenia gravis is caused by autoimmune failure, making that autoantibodies that destroy on the muscular acetylcholine receptor generated. The result is an anomalous and ineffectual muscle contraction which causes muscle weakness and easy voluntary muscles fatigue exclusively, and that increases with physical activity and improves with rest. It seems to be in the thymus gland (between lungs and heart) where the failure occurs because eight out of ten affected have alterations in her (hyperplasia, tumor).
This disease occurs at any age, although it is most common in women between 20 and 40 years old and men from 50-60. In terms of its prevalence, detected 1 to 2 new cases per year per 100,000 inhabitants, and it is estimated that there are between 150-200 cases per million. In Spain, there are about 10,000 affected.
Although it is highly variable, more active phase is generally in the first seven years, being in the first two when more progress. There is a genetic predisposition to develop it. Autoimmune diseases are associated with including, myasthenia gravis can do it (5-10%) with: Thyroiditis, rheumatoid arthritis, lupus, Crohn's disease, Pemphigus, and so on.
There is congenital myasthenia (very rare), which although it can share symptoms with the autoimmune MG, is different. It is caused by a genetic disorder and is inherited.

Types and symptoms of myasthenia gravis

There are two groups or types of myasthenia gravis clinically well differentiated, the ocular myasthenia and generalized myasthenia gravis:
Ocular myasthenia
It represents 20% of the MG. seven in ten affected begin presenting ocular symptoms; of them, 80% are evolving to form widespread in 1-3 years. Half of this group are seronegative.
Myasthenia gravis generalised
It represents 80% of the cases. Ocular muscles of the trunk and extremities are affected. Other forms include:
  • Bulbar: affect muscles of the face, palate, speaking and swallowing.
  • Respiratory: (the most severe) respiratory muscle involvement.
  • HIV-negative: 6-12% of patients do not have antibodies against the acetylcholine receptor, but yes is detected him, to 50% of them, antibodies anti-musk, indicating a worse prognosis.
  • Transient Neonatal: 10-20% of newly born mothers miastenicas suffer from MG by the passage of antibodies through the placenta. Cause weak cry, difficulty of suction, muscular flaccidity. It appears in 48-72 hours and can last up to 2-3 months. It is passed.
  • A drug-induced: "penicillamine" (for rheumatoid arthritis) can induce a transient myasthenia.
  • Spontaneous remission: in 20% of cases in its first years of evolution.

Symptoms of myasthenia gravis

Myasthenia gravis symptoms vary intensity in a single day, or a day to another (fluctuation), and their characteristics depend on the affected muscles:
  • Eyepieces: vision (diplopia) double, blurry, sagging eyelids (ptosis).
  • Bulbares: difficulty speaking (dysarthria), swallowing (dysphagia), chewing, loss of expressiveness, vertical smile, hoarseness, nasal voice.
  • Thrust: weakness in neck and spine.
  • Tips: weakness in arms and legs.
  • Respiratorios: difficulty coughing, breathing (myasthenic crisis).

Special situations

  • Crisis myasthenic: respiratory muscles are affected generally by an infection. As a warning, there is usually before bulbar weakness. It is a medical emergency that requires admission to ICU (mechanical ventilation).
  • Gravis and pregnancy: gestation is not contraindicated, but there is a risk of the crisis in the first trimester of pregnancy and during labor and childbirth. One-third of pregnant women are stable, one-third better, and the rest get worse. Not usually recommended breastfeeding.

Psychological aspects of myasthenia gravis

People affected by myasthenia gravis live always based on effort and supporting a great emotional charge.
In many cases, the MG has a difficult diagnosis. Its insidious onset, symptoms similar to other illnesses, and the lack of medical knowledge, have made that those affected have taken long time (sometimes years) to be diagnosed. This has caused them anxiety, anguish, and depression.
We must be prepared to change permanent. We live with uncertainty, because we do not know how long welfare and appears again when the symptoms which we invalidated. We know how the day will be introduced and how we feel after a few hours, myasthenia gravis is fickle and fluctuating. With the course of the day we lose vitality by the use of muscles, and we will gradually weaken us. Easy wash, comb, walk, or climb stairs we can be a world.
Family, friends, coworkers, do not perceive that we are sick because the MG is often priceless, invisible in the eyes of others; the weakness can change in hours, from one day to another, which disorients over all.
Socially we can not keep up, we are no longer useful to the work, the family usually does not understand what happens to us. All this is generating anxiety, stress, changes of character, low self-esteem, and incommunicado detention, and we tend to isolate us.

Diagnosis of myasthenia gravis

Myasthenia gravis diagnosis is based on clinical suspicion, confirmed with further tests.
Suspect in clinic
Exploration is observed if there are dual-view, appearance of muscle fatigue after performing a repetitive exercise, fall of eyelids (here "the ice test" is appropriate for two minutes on a drooping eyelid and see its effect), etc.
The edrophonium or tensilon test
It is used in patients with eyelid drop or view double. It is to inject 2 mg of a drug called edrophonium (Tensilon) and check if the symptoms; they disappear in 1 minute the improvement lasts 5 minutes. It is necessary to have "atropine" to neutralize the possible adverse effects of the drug (arrhythmia, hypotension, bradycardia). The sensitivity of the test is 80-90%, but the result may be associated to false negatives and false positives.
Electrophysiological studies
  • Repetitive nerve stimulation: a nerve (6-10 times), check if changes occur in the muscle contraction. In the MG decrease there is > 10%, the fourth stimulus. 75% in the MG widespread sensitivity.
  • Single fiber electromyography: stimulation of two individual muscle fibers. In MG is increasing the time of contraction of the second to the first. This test has a sensitivity of 95%, although it is not specific to myasthenia gravis.
Serological tests
  • Of acetylcholine receptor antibodies: if (+) confirm the MG. are present in 80-90% of the MG generalized and 50% of ocular MG.
  • Antibody anti-Musk: are (+) in 50% of patients with antibodies anti acetylcholine (-).
  • Negative antibodies: not detected any but it suffers from the MG.
  • Other antibodies: "anti-musculo spline", "anti-titina" and "anti-ryanodine".
Other tests to diagnose myasthenia gravis
  • Analyses of blood: to detect the possible presence of associated autoimmune diseases (lupus, thyroiditis, rheumatoid arthritis...).
  • Radiological testing: nuclear magnetic resonance (NMR), TAC... for the differential diagnosis.
Differential diagnosis of myasthenia gravis
There are other diseases that have symptoms similar to myasthenia gravis:
  • Myasthenia gravis eye: thyroid ophthalmopathy, chronic progressive external ophthalmoplegia, myotonic dystrophy pathology of the brain stem.
  • Myasthenia gravis general: Fatigue chronic botulism, congenital myasthenic syndromes, motor neuron disease, obstructive lesions of the oropharynx.

Treatment of myasthenia gravis

The treatment of myasthenia gravis is individualized and depends on the age of the patient, is clinical, severity and rate of progression of the disease. Treatments are used individually or combined, and sometimes induce a remission. There are four basic therapies: the anticolinesterasciso, chronic immunotherapies, fast immunotherapies and thymectomy.


It is symptomatic and is the first line of treatment.
  • Pyridostigmine: the most frequent anticolinesterasico. It prolongs the effect of acetylcholine on the muscle receptor. Its effect starts in 10-15 minutes and maximum two hours. Its excess causes a cholinergic crisis (diarrhea, abdominal cramps, sweating, weakness...).

Chronic immunotherapies

Decrease the amount of antibodies in blood.
  • Glucocorticoids: first line of immune suppression. Use in acute crisis. Effective in 2-3 weeks. In the long run, they have serious side effects.
  • Azathioprine: first line to combine. Weak action, begins in 6-12 months. Adverse effects: Suppression of bone marrow and liver toxicity.
  • Mycophenolate mofetil: little powerful action, begins in 6-12 months. Gastrointestinal effects and suppression of bone marrow.
  • Cyclosporine: Powerful action. Please effect in six months. It requires regular blood checks. Effects: hypertension and renal toxicity.
  • Tacrolimus: powerful action at low doses. Similar to Cyclosporin, but less nephrotoxic. It requires regular blood checks.
  • Rituximab: therapy (novel) monoclonal for myasthenia gravis rebel.
  • Cyclophosphamide: in severe myasthenia that does not respond to other therapies. It has serious side effects.
  • Methotrexate: currently under study.

Fast immunotherapies

Used for myasthenic crisis, control of relapses, and surgical preparation.
  • Plasmapheresis: 5-7 spare parts of the blood plasma in two weeks to remove antibodies. The effect lasts about six weeks. It should be associated with other immunosuppressive treatments. Adverse effects: venous catheter, hemorrhage, hypotension.
  • Intravenous immunoglobulins: are used for five consecutive days for neutralizing antibodies. The effect lasts for two months. Adverse effects: shivering, headache, venous thrombosis, hepatitis or AIDS (very rare).

Surgical treatment of the thymus (thymectomy)

It is required when there is tumor thymic (thymoma) that in 60% of cases, is benign.
It is also recommended in patients under 60 years, in the generalized form of bulbar and respiratory. Not recommended in the eye form. The benefit is greater if it is done in the first three years of evolution of myasthenia gravis. It starts its effect between 1-5 years and maximum about 10 years. (Inactivation of myasthenia gravis) remissions in 65% of patients are reached. It has doubtful effect in patients with anti-musk (+).

Myasthenia gravis prognosis

In the middle of the last century, the classification of Osserman grouped in grades different types of muscular involvement of myasthenia gravis for a better classification, prognosis and treatment. Currently, American myasthenia Foundation reclassified in mild, moderate and severe degree.
  • Grade I. eyepiece. Exclusively ocular involvement. Very disabling and clinically unimportant. It responds poorly to symptomatic treatment with anticholinesterase. Good prognosis.
  • Grade II-a. Widespread. Ocular involvement, trunk, and extremities. Without crisis. Good response to medical and surgical treatment. Good prognosis.
  • Grade II-b. Bulbar. Ocular, bulbar and general involvement. There may be "myasthenic crisis" by disorder of swallowing (aspiration pneumonia). Worst prognosis and good response (slow) to medical and surgical treatment.
  • Grade III. Acute respiratory. General, bulbar and respiratory involvement. Home quick and sharp. Forecast bad, with frequent miastenicas crisis. Medical surgical and inconstant good response.
  • Grade IV. Respiratory tardive. Of long evolution, with little important clinical and that is suddenly complicated with respiratory muscle involvement. Very poor prognosis due to the frequent crises miastenicas. Poor surgical response.
According to the serological study:
  • (+) Acetylcholine receptor antibodies: its determination is disproportionate to the severity of the MG but with the response to medical and surgical treatment, which is usually good. Better prognosis.
  • Antibody anti-Musk (+): more frequent in women. There is bulbar symptoms and respiratory crisis; worse, they respond to symptomatic but best to immunosuppressant treatment. The surgery has an uncertain role. Worse prognosis.
  • Antibodies (-): those affected may have a MG heterogeneous (eye, generalized mild or severe). They tend to respond well to medical and surgical treatment. Irregular prognosis.
  • Other antibodies: striated anti-musculo (+), anti-titina (+) and anti-ryanodine (+): predict myasthenia gravis thymus tumor-related. They are also related to MG of late onset. Worse prognosis.

Tips for living with myasthenia gravis

Usually this disease tends to become stable, and with proper monitoring and treatment, the life expectancy of those affected may be similar to that of the healthy population. Below, we offer some tips to improve your quality of life and learn to live with myasthenia gravis.

Plan activities

Prioritizes, choose most importantly of what you want to do in the day. Learn to listen to your body to know when "push the accelerator and when to release it"), and when you've taken too much effort and learn to retrieve you. Plan the day, know your limits, fractionated activities and prevents overloading yourself.
It conserves energy
Program and alternating periods of rest. It delegates tasks to family members. Avoid insomnia, you need to sleep well (adopt healthy habits that improve sleep). It decreases the stress with relaxation and breathing techniques. Try to be physically active (aerobic exercise), and prevents overweight.
Known / controlled risk factors which can decompensate myasthenia gravis
Medicines (antibiotics, relaxants, anesthetic, antiepileptic drugs, antipsychotics, beta-blockers...). Emotional stress. Excessive exercise. Heat, humidity and extreme cold. Infections. Surgery. Sleep disturbance. Menstruation, pregnancy and menopause. Excessive alcohol. Insect bites. Excessive brightness. Certain foods and beverages (mushrooms, pistachios, Brussels sprouts, tonic, bitter, quinquina wine).
The daily with myasthenia
Change the "how" and "when" do chores. Sit while you do them. Use the tools comfortable to handle. Avoid domestic accidents, because you have higher risk of injury than the healthy population. Use comfortable shoes. Use patches to correct the double vision (reading, watching television). It carries a bracelet or medical alert sheet indicating that you suffer from myasthenia.
Power for myasthenia gravis
Balanced, easy to chew and swallow food. Eat little and often, weary you less. But if you eat small amounts, make sure that foods are nutritious. Frequently drink while you eat, you swallow better. If you take steroids, it takes food with fewer calories and little salt. Controls diarrhea caused by the anticholinesterase.
Exercise with myasthenia gravis
Recommended. It improves muscle strength, mood, sleep, stress, heart function and osteoporosis. Always do it within your limits, without excesses. Practice gentle aerobic exercise (cycling, swimming, walking). Avoid strenuous and repetitive exercise of the muscles. Does not practise it in hot environments.

Emergency situations

A respiratory crisis can be fatal for a patient with myasthenia gravis, and also at a greater risk of choking. Emergency situations in which you will learn how to act are:
  • Crisis myasthenic: vital urgency. Sharp aggravation of respiratory muscles that causes difficulty breathing. Usually having notified impaired swallowing, coughing, talking. Keep the airway open. It is extracted from the mouth secretions. It helps the patient breathe rising and descending arms. Place the seated patient and supported arms (help to breathe). Try a quiet until the ambulance arrives.
  • Choking: By a foreign body airway obstruction. Heimlich maneuver. Hug the patient back, place right fist into your stomach (between the navel and the breastbone) and grab the handle with your left hand, press suddenly with force and up. If you are unconscious or very obese, is on the ground, placed a hand with the fist closed above the navel, the other hand resting on the first, and press strong and sharply upward, pushing with your weight.

Attitude to myasthenia gravis

The patient with myasthenia gravis should assume nothing will be as before; rethink your life and adapt to the new stage which is going to play live. And, to do so, should understand the disease, assimilate it and familiarize yourself with it.
Get ready to "go changing permanently". Reinvent your life, adapt it to myasthenia gravis and find your space, with realistic goals and short term. Prepare for relapse, they are exhausting and provoke strong mood changes.
Be positive attitude, take on the MG as a challenge, not you're always regretting you and looking for solutions. Take control of your life, risk factors, makes decisions that improve your quality of life, and shows your needs. Stay motivated. Trust in yourself and your possibilities. Trust in others and allow you to ask for help.
Contact with AMES (Association myasthenia Spain), are there to help you. There are "coping programs" to reduce the psychological consequences, including group, relaxation, coexistence conference workshops, therapy etc.
The family must give time to the patient regret what has lost. Be there to listen to you and understand your sentiment, but pity him. Prepare for your changes and unpredictable ups and downs. It is important to have in mind that the symptoms are not always noticeable. You should not minimize their complaints, because it needs to express their desperation. Learn everything you can about the MG and don't be afraid to talk about the disease with him. Learn to recognize when you need help beyond that you can offer you, and encourage you to seek professional support if necessary.
Live with a patient with myasthenia gravis is not easy. Don't ask you to keep the mood when there is little power or that efforts because it may be the limit. You have patience, you not force you to fight a battle also with its surroundings. Provides help in its limited activities and encourage you to realize that allow its symptomatology. Remember that the patient who suffers Gravis all they want is to participate with maximum normal life.
Published for educational purposes
Health and Wellness

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