14/11/2022
What to know about myasthenia gravis?
Myasthenia gravis is a relatively rare neuromuscular disease in which the voluntary muscles easily become tired and weak because there is a problem with how the nerves stimulate the contraction of muscles. It is an autoimmune disorder.
“Myasthenia gravis” literally means “grave muscle weakness,” but many cases are mild, and life expectancy is normal.
The muscles around the eyes tend to be affected first, causing the eyelids to droop. Patients may experience double vision, weakness in the arms and legs, and difficulties chewing, swallowing, speaking, and breathing. Involuntary muscles, such as the heart muscles, are not affected.
Symptoms often worsen with physical activity and improve after resting or a good night’s sleep. There is no cure, but treatment can relieve and even remove symptoms.
The condition affects 14 to 20 people in every 100,000 in the United States, or between 36,000 and 60,000 people. It can happen at any age, but it is more likely to affect women before the age of 40 years, and men after the age of 60 years.
Treatment
With myasthenia gravis, the limbs can weaken.
There is no cure for myasthenia gravis, but treatment with immunosuppressants or cholinesterase inhibitors can help control symptoms.
Many patients find that with treatment, and adequate sleep and rest, they can carry on with their normal routine.
Medications include:
Cholinesterase inhibitors: These improve communication between nerves and muscles, and are effective in patients with mild symptoms of MG.
Steroids, such as prednisolone, or immunosuppressants, such as azathioprine, may alter the body’s immune system so that it produces fewer of the antibodies that cause MG.
It usually takes about 4 weeks for steroids to take effect. Azathioprine may take from 3 to 6 months, but it brings about a significant reduction or complete removal of symptoms.
In the case of a tumor, the thymus gland may be surgically removed in a thymectomy.
For patients with severe or life-threatening symptoms, plasmapheresis and immunoglobulin therapy can be administered in the hospital.
Plasmapheresis involves depleting the body of blood plasma without depleting the body of its blood cells, in order to remove the unwanted antibodies.
Intravenous immunoglobulin therapy involves injecting the patient with normal antibodies that change the way the immune system acts.
These treatments are effective, and they work quickly, but the benefits last only a few weeks, so this is a short-term treatment.
