Managing Myasthenia Gravis

You have droopy eyelids. You also experience double vision. You have trouble climbing the stairs. You could have myasthenia gravis.

Myasthenia gravis (MG) is an autoimmune disease, meaning the body’s immune system attacks its own parts. According to the Cleveland Clinic, MG affects the communication between nerves and muscles (the neuromuscular junction).

Those with MG lose the ability to control muscles voluntarily. They experience muscle weakness and fatigue of various severity. They may not be able to move muscles in the eyes, face, neck and limbs. MG is a lifelong neuromuscular disease. There is no cure for MG but some patients achieve remission and treatments are useful.

It most commonly impacts young adult females (under 40) and older males (over 60) but it can occur at any age, including childhood but it is very rare.

Certain factors may increase risk such as:

§  History of other autoimmune diseases, such as rheumatoid arthritis and lupus.

§  Infections.

§  Medications for heart arrhythmias, cancer and malaria.

§  Surgical procedures.

§  Thyroid disease.

Autoimmune MG is considered the most common form of this disease. Autoimmune MG may be:

§  Ocular (your eyelids droop and it is difficult to keep them open and you have double vision). Eye weakness is often the first sign of MG.

§  Generalized (muscle weakness affects the eye and other body parts such as the face, neck, arms, legs, and throat). You may find it difficult to swallow and speak, stand up from a seated position, walk long distances, lift your arms over your head and climb stairs.

MG isn’t inherited. In fact, it is rare for more than one family member to receive a diagnosis of autoimmune MG. On the other hand, the nonautoimmune form of MG can affect more than one family member.

A pregnant woman cannot pass MG on to her infant. About one in 10 babies develop a temporary condition known as neonatal myasthenia where these infants will have weak cries or sucking reflexes at birth. These symptoms go away in a couple of weeks. This condition doesn’t increase a child’s chances of developing MG in the future.

MG is an autoimmune disease where the immune system attacks itself. In a healthy immune system, nerves and muscles work together like this:

1.     Nerves send signals to muscles across a synapse (connection) called the neuromuscular junction. In order to communicate, nerves release a molecule known as acetylcholine.

2.     Muscles have sites called acetylcholine receptors. The acetylcholine binds to the receptors in the muscle tissue.

3.     When the acetylcholine binds to the receptor, it causes the muscle fiber to contract.

Nerves signal muscles to work effortlessly in a healthy person.

But people with MG have antibodies that destroy the receptor sites, which blocks nerve-muscle communication.

Many people with MG have thymus gland conditions that bring about MG. The thymus is a small organ in the upper chest that is a part of the lymphatic system. It makes white blood cells that fight infections.

Symptoms of MG often come on suddenly. The disease causes your muscles to get weaker when you’re active. Muscle strength returns when you rest. Most people feel strongest at the start of the day and weakest towards the end of the day. Symptoms of MG are double vision; drooping eyelids (ptosis); difficulty speaking, chewing and swallowing; difficulty moving their neck up or holding up their head; limb weakness; and trouble walking.

Though rare, MG may affect muscles in your respiratory system. You may have shortness of breath or more serious breathing problems.

To diagnose MG, your provider will perform a physical exam as well as other exams including:

§  Ice pack test. If you have drooping eyelids, your provider may place ice packs over your eyes or have you rest with your eyes shut in a dark room for a couple of minutes. If the drooping improves after the ice application or rest, you may have MG.

§  Antibody tests. About 85 percent of people with MG have unusually high levels of acetylcholine receptor antibodies in their blood. Approximately 6 percent of patients have muscle-specific kinase antibodies. Antibodies may not be detected in less than 10 percent of MG patients.

§  Imaging scans. An MRI or CT scan can check for thymus gland problems like tumors.

§  Electromyogram (EMG). An EMG measures the electrical activity of muscles and nerves and picks up on communication problems between the nerves and muscles.

Up to one in five people with MG experience a myasthenic crisis or a severe respiratory muscle weakness. They may require a respirator or other treatments to help them breathe. This is a serious medical emergency. Weak muscles, infections, fevers and reactions to medications can cause a crisis.

MG is a highly treatable condition and most patients live normally with treatment. Treatments may include medications like corticosteroids; monoclonal antibodies; IV immunoglobulin; plasma exchange and surgery like a thymectomy to remove the thymus gland.

If you have MG, there are certain steps you can take to head off fatigue and muscle weakness such as avoid going outside in the middle of a hot day; exercise regularly to strengthen muscles and have more energy; eat plenty of protein and carbohydrates for energy; do your most exhausting activity earlier in the day; and take naps throughout the day.

With proper treatment, patients with MG can lead full and active lives. Contact your health provider if you suspect that you have MG.