Description

Myasthenia gravis (my-us-THEE-nee-uh GRAY-vis) makes the muscles under your voluntary control feel weak and gets tired quickly. This happens when the communication between the nerves and muscles breaks down.

There is No cure for myasthenia gravis. The treatment may help with symptoms. These symptoms may include weakness of one arm or leg muscles, double vision, drooping eyelids, and problems with speech, chewing, swallowing, and breathing.

This disease can affect people of any age, but is most common in women under the age of 40 and in men older than 60 years.

Symptoms

Muscle weakness caused by myasthenia gravis gets worse when the affected muscle is used. Because the symptoms tend to improve with rest, the muscle weakness can come and go. However, the symptoms tend to progress over time. Tend to reach their worst within a couple of years after the disease begins.

Myasthenia gravis may affect any of the muscles you can control. Certain muscle groups are more commonly affected than others.

The muscles of the eyes

In more than half of the people who suffer from myasthenia gravis, their first symptoms affect the eyes. The symptoms include:

  • Drooping of one or both eyelids, called ptosis.
  • Double vision, called diplopia, which can be horizontal or vertical, and improves or resolves when one eye is closed.

The face and the muscles of the throat

In approximately 15% of people with myasthenia gravis, the first symptoms include the face and the muscles of the throat. These symptoms can be:

  • Make it difficult to speak. Your voice can sound smooth or nose, according to which the muscles are affected.
  • Cause problems with swallowing. You can drown easily, making it difficult to eat, drink or take pills. Sometimes, the liquid that you are trying to swallow out of her nose.
  • Affect chewing. The muscles used for chewing may tire half way through a meal. This is especially true if you have been eating something that is difficult to chew, such as steak.
  • Change the facial expressions. For example, your smile may seem like a growl.

The neck and the muscles of the extremities

Myasthenia gravis can also cause weakness in the neck, arms and legs. Weakness in the legs can affect the way you walk. Weak muscles of the neck make it difficult to maintain the head.

When to see a doctor

Talk with your health care provider if you have problems:

  • Breathing.
  • To see.
  • Swallowing.
  • The chewing.
  • Walk.
  • The use of her arms or hands.
  • Holding her head up.

Causes

Antibodies

His nerves communicate with the muscles by the release of chemical substances, called neurotransmitters, that fit in the places in muscle cells, the so-called receptor sites in the nerve-muscle junction.

In myasthenia gravis, the immune system produces antibodies that block or destroy many of their muscles' receptor sites of a neurotransmitter called acetylcholine (as-uh-teel-KOH-leen). With fewer receptor sites available, the muscles receive fewer nerve signals. This causes weakness.

The antibodies can also block a protein called muscle-specific receptor tyrosine kinase (TIE-roh-seen KIE-votes against), sometimes referred to as the Musk. This protein helps to form the nerve-muscle junction. Antibodies against this protein can lead to myasthenia gravis.

Antibodies to another protein, called lipoprotein-related protein 4 (LRP4), may play a role in this condition. Research studies have found other antibodies and the number of antibody involved is likely to grow with time.

Some people have myasthenia gravis that is not caused by antibodies blocking of acetylcholine, Musk or LRP4 . This type of myasthenia gravis is called seronegative myasthenia gravis, also known as antibody-negative myasthenia gravis. In general, researchers believe that this type of myasthenia gravis still comes from a problem with autoimmunity, but the antibodies involved may not be found yet.

The thymus gland

The thymus gland is a part of your immune system. This gland is located in the upper part of the chest, under the breastbone. The researchers believe that the thymus gland makes or helps to produce antibodies that block acetylcholine.

The thymus gland is large in infants and small in healthy adults. In some adults with myasthenia gravis, however, the thymus gland is larger than usual. Some people with myasthenia gravis also have tumors of the thymus gland, called thymomas. Generally, thymomas are not cancerous, also known as malignant. But thymomas may become cancerous.

Other causes

Rarely, mothers with myasthenia gravis have children who are born with myasthenia gravis. This is called neonatal myasthenia gravis. If treated right away, the children usually recover within two months after birth.

Some children are born with a rare inherited form of myasthenia gravis, the so-called congenital myasthenic syndrome.

Factors that may cause myasthenia gravis worse include:

  • Fatigue.
  • Disease or infection.
  • Surgery.
  • Stress.
  • Some medications such as beta blockers, quinidine gluconate, quinidine sulfate, quinine (Qualaquin), phenytoin (Dilantin), certain anesthetics, and some antibiotics.
  • Pregnancy.
  • The menstrual periods.

Complications

The complications of myasthenia gravis are treatable, but some can be deadly.

Myasthenic Crisis

Myasthenic Crisis is a life-threatening condition. This occurs when the muscles that control breathing become too weak to work. Emergency treatment and the mechanical assistance to breathe are required. Drugs and therapies that filter the blood to help people to breathe on their own.

Tumors of the thymus gland

Some people with myasthenia gravis have a tumor in the thymus gland. The thymus is a gland that is located below the sternum, which is part of the immune system. The majority of these tumors, called thymomas, are not cancerous.

Other disorders of the

People with myasthenia gravis are more likely to have the following conditions:

  • Hypothyroidism, or an overactive thyroid. The thyroid gland in the neck and secretes hormones that regulate the metabolism. If the thyroid is underactive, you may have problems to cope with the cold, weight gain and other problems. An overactive thyroid can cause problems to deal with the heat, weight loss, and other problems.
  • Autoimmune conditions. Persons with myasthenia gravis may be more likely to have autoimmune diseases, such as rheumatoid arthritis or lupus.

Diagnosis

Your health care provider will review your symptoms and medical history and perform a physical exam. Your doctor may use several tests, including:

Neurological examination

Your healthcare provider may check your neurological health through the test:

  • Reflections.
  • The muscle strength.
  • The muscle tone.
  • The senses of touch and sight.
  • Coordination.
  • Balance.

Tests to help confirm a diagnosis of myasthenia gravis may include:

Ice pack test

If you have droopy eyelids, your provider may put a bag full of ice on the eyelid. After two minutes, the doctor pulls out of the bag and examines her heavy eyelids for improvement.

The analysis of blood

A blood test can show nontypical antibodies that disrupt the receptor sites where the nerves signal the muscles to move.

Repetitive nerve stimulation

In this study of nerve conduction, suppliers, connect the electrodes to the skin over the muscles to be tested. Small pulses of electricity run through the electrodes. These pulses to measure if the nerve can send a signal to the muscle.

During this test, the nerve is tested several times to see if their ability to send signals worsens with fatigue. The results of this trial will help to inform a diagnosis of myasthenia gravis.

Single-fiber electromyography (EMG)

This test measures the electrical activity that travels between the brain and the muscle. It consists in the introduction of a fine wire electrode through the skin and into the muscle of the test of a single muscle fiber.

Images

Your healthcare provider may order a ct scan or an mri to check if there is a tumor or any other problem with your thymus.

Pulmonary function tests

These tests measure if your condition is affecting your breathing.

Treatment

Various treatments, alone or together, can help with the symptoms of myasthenia gravis. Your treatment will depend on your age, the severity of your disease is and how fast it is progressing.

Drugs

  • Cholinesterase inhibitors.Medications such as pyridostigmine (Mestinon, Regonal) to improve the communication between the nerves and the muscles. These medications are not a cure, but it can enhance the muscle contraction and muscle strength in some people. Possible side effects include gastrointestinal upset, diarrhea, nausea, and excessive salivation, and sweating.
  • Corticosteroids. Corticosteroids such as prednisone (Rays) to block the immune system, so that it is less able to produce antibodies. The use of corticosteroids for a long period of time, however, it can cause serious side effects. These include thinning of bones, weight gain, diabetes, and increased risk of infections.
  • The inmunosupresores.Su a professional doctor may also prescribe other medications that change your immune system. These medications may include azathioprine (Azasan, Imuran), mycophenolate mofetil (Cellcept), cyclosporine (Sandimmune, Gengraf, others), methotrexate (Trexall), or tacrolimus (Astagraf XL, Prograf, other). These medications, which can take months to work, it could be used with corticosteroids. Side effects of immunosuppressive drugs, such as an increased risk of infection, and liver or kidney damage, can be serious.

Cholinesterase inhibitors. Medications such as pyridostigmine (Mestinon, Regonal) to improve the communication between the nerves and the muscles. These medications are not a cure, but it can enhance the muscle contraction and muscle strength in some people.

Possible side effects include gastrointestinal upset, diarrhea, nausea, and excessive salivation, and sweating.

The immunosuppressants. Your healthcare provider may also prescribe other medications that change your immune system. These medications may include azathioprine (Azasan, Imuran), mycophenolate mofetil (Cellcept), cyclosporine (Sandimmune, Gengraf, others), methotrexate (Trexall), or tacrolimus (Astagraf XL, Prograf, other). These medications, which can take months to work, it could be used with corticosteroids.

Side effects of immunosuppressive drugs, such as an increased risk of infection, and liver or kidney damage, can be serious.

Iv therapy

The following therapies are usually used for a short period of time to treat the symptoms suddenly get worse or before a surgery or other treatments.

  • Plasmapheresis (plaz-muh-fuh-REE-sis).This procedure uses a filtering process that is as dialysis. Your blood through a machine that removes antibodies that block the transmission of signals from the nerves to the muscles. However, the good effects of this procedure is usually only last a couple of weeks. Have several procedures that can lead to problems to find the veins for the treatment. The risks of plasmapheresis include a drop in blood pressure, bleeding problems, heart rhythm problems, or muscle cramps. Some people have an allergic reaction to the solutions used to replace plasma.
  • Intravenous immunoglobulin (Ivig).This therapy provides your body with the typical antibodies, which alters the immune response. The benefits are usually seen in less than a week and can last for 3 to 6 weeks.
  • Monoclonal Antibody. Rituximab (Rituxan), and eculizumab (Soliris) are drugs that are administered intravenously to myasthenia gravis. These medications are usually used when other treatments do not work. They can have serious side effects.

Plasmapheresis (plaz-muh-fuh-REE-sis). This procedure uses a filtering process that is as dialysis. Your blood through a machine that removes antibodies that block the transmission of signals from the nerves to the muscles. However, the good effects of this procedure is usually only last a couple of weeks. Have several procedures that can lead to problems to find the veins for the treatment.

The risks of plasmapheresis include a drop in blood pressure, bleeding problems, heart rhythm problems, or muscle cramps. Some people have an allergic reaction to the solutions used to replace plasma.

Intravenous immunoglobulin (Ivig). This therapy provides your body with the typical antibodies, which alters the immune response. The benefits are usually seen in less than a week and can last for 3 to 6 weeks.

The side effects are generally mild, may include chills, dizziness, headache, and fluid retention.

Surgery

Some people with myasthenia gravis have a tumor in the thymus gland. If you have a tumor, called a thymoma, you're going to need a surgery to remove the thymus gland, called the thymectomy.

Even if you don't have a tumor in the thymus gland, removal of the gland may improve your symptoms. However, the benefits of this surgery can take years to develop.

Thymectomy can be performed as an open surgery or as minimally invasive surgery. In open surgery, the surgeon divides the central breastbone, called the breastbone (sternum) to open the chest and remove the thymus gland.

Minimally invasive surgery surgery to remove the thymus gland uses smaller cuts, called incisions. It might also involve:

  • Video-assisted thymectomy. In one form of this surgery, surgeons make a small opening in the neck or a pair of small openings in the side of the chest. Then, use a long, thin camera, it is called a video endoscope, and small instruments to see and remove the thymus gland.
  • Robot-assisted thymectomy. In this form of thymectomy, surgeons make several small incisions in the side of the chest. They used a robotic system to remove the thymus gland. This system includes a camera arm and mechanical arms.

These procedures may result in less blood loss, less pain, lower mortality rates and hospital length of stay compared with open surgery.

Lifestyle and home remedies

To help you make the most of your energy and cope with the symptoms of myasthenia gravis:

  • Adjust your routine to eat. Try to eat when you have good muscle strength. Take your time to chew your food, and take a rest between bites of food. You might find that it's easier to eat small meals several times a day. Also, try to eat mostly soft foods and avoid foods that require more chewing, such as raw fruits or vegetables.
  • The use of safety precautions at home. Install grab bars or handrails in places where you need the support, such as next to the bath or in the following steps. Keep the floors clean, and move rugs. The outside of your house, maintain the roads, sidewalks and driveways cleared of leaves, the snow and other debris that could cause you to trip.
  • The use of appliances and power tools. To save your energy, try using an electric toothbrush, electric can openers, and other electrical appliances tools to perform the tasks.
  • To wear an eye patch. If you have double vision, an eye patch can help. Try using one for writing, reading or watching tv. Change the eye patch to the other eye on a regular basis to help reduce the visual fatigue.
  • Plan. If you have chores, go shopping or errands to do, the plan of activity for when you have more energy.

Coping and support

Deal with myasthenia gravis may be difficult for you and your loved ones. Stress may make your condition worse, so find ways to relax. Ask for help when you need it.

Learn all you can about your condition, and have their loved ones to learn about it. Everyone could benefit from a support group, where you can meet people who understand what you and your family members are going through.

Preparing for your appointment

It is likely that you first consult your primary care provider, who then consult a doctor trained in nervous system conditions, call a neurologist for further evaluation.

Here is the information to help you prepare for your appointment.

What you can do

Bring a friend or a family member to help you understand the information you're given. Make a list of:

  • Your symptoms and when they began.
  • All medications, vitamins or supplements that you take, including over-dose.
  • Questions to ask your provider.

For myasthenia gravis, questions to ask your provider include:

  • What is likely causing my symptoms?
  • What tests do I need?
  • What course of action do you recommend?
  • What are the alternatives to the approach that you're suggesting?
  • I have other health conditions. How can I best manage them together?
  • There are restrictions that must be followed?
  • Are there brochures or other printed material I can have? What sites do you recommend?

Do not hesitate to ask other questions.

What to expect from your doctor

Be prepared to answer questions to your provider is likely to ask, such as:

  • The symptoms been continuous or occasional?
  • How severe are the symptoms?
  • What, if anything, seems to improve your symptoms?
  • What, if anything, appears to worsen your symptoms?
Symptoms and treatment of Myasthenia gravis