Myasthenia gravis is a chronic neuromuscular disease that affects women less than 40 and then older than 60 in varying degrees. The condition affects the voluntary muscles of the body which means those muscles that are under control of the individual. The name, myasthenia gravis, literally means grave muscle weakness. But, unlike the implication, the condition is not grave.
The hallmark symptom is muscle weakness which increases during periods of activity and improves after periods of rest. There are specific muscles which appeared to be more affected by the disease such as those that control the eye and eyelid movement, facial expressions, chewing, talking and swallowing. The muscles that control breathing, neck, and limb movement may also be affected.
At this time researchers believe that there is a relationship between the thymus gland and myasthenia gravis but that relationship is not yet fully understood. The thymus glands plays an important role in the development of the immune system. Some individuals may develop thymomas or tumors of the thymus gland which are generally benign but appear to trigger the condition of myasthenia gravis.
Although there is no known cure for myasthenia gravis there are treatments that can prolong periods of remission. Individuals will find that lifestyle adjustments can also help them continue many of their previous activities. Activities should be planned to allow rest during the day and those individuals who suffer from double vision may find that an eyepatch is helpful. Changes in lifestyle should include stress reduction techniques and decreasing excessive heat exposure because they also worsens symptoms.
Individuals who suffer from myasthenia gravis can also benefit from certain medications that can improve the communication between the nerve and muscle. Drugs such as pyridostigmine will enhance the communication between nerves and muscles but do not cure the underlying problem. These drugs prevent the destruction of certain biochemicals which increases the accumulation of them at the neuromuscular junctions and improves the ability of the muscles to contract.
Patients who use these drugs may suffer from excessive salivation, involuntary muscle twitching, abdominal pain, nausea or diarrhea. There are medications which a physician may prescribe in order to decrease the gastrointestinal side effects for patients.
There are times when physicians will order corticosteroids such as prednisone to suppress the immune system and the nerve bodies at the neuromuscular junction. These improve symptoms within a few weeks but only if the anti-cholinesterase medications are working well. Once improvement stabilizes the dose will slowly be decreased because side effects such as gastric ulcers, osteoporosis, high blood sugar, weight gain and increased risk for infection may outweigh the benefits of using this medication.
When other treatments do not improve the patient\’s symptoms there are options available such as surgical removal of the thymus gland that can results in permanent remission or the need for less medications. People with eye problems can try using lens prisms to improve vision or surgery is an option to strengthen the eye muscles.
Another option for treatment is plasmapheresis which is a technique where blood plasma containing the antibodies against the body are removed and replaced with fluids. This can reduce symptoms for up to four to six weeks and may be used to optimize conditions before individual undergoes surgery. Risks include low blood pressure, dizziness, blurred vision and formation of blood clots.
Despite muscle weakness and the long-term effects of myasthenia gravis the prognosis is usually good. This symptoms will usually progress to their maximum severity within the first three years. After three years symptoms usually stabilize or improve. Individuals over the age of 40 with a short history of severe disease or those who have developed a tumor on their thymus gland will have a worse prognosis.
Because early treatment is important in the prognosis of myasthenia gravis individuals who feel they have symptoms are best served by seeking the advice and diagnosis of their physician so they may begin treatment.
RESOURCES
National Institute of Neurological Disorders and stroke: Myasthenia Gravis Fact Sheet
MayoClinic: Myasthenia Gravis
Myasthenia Gravis Foundation of america: Treatment for MG
The Dana Foundation: Myasthenia Gravis
American Academy of Neurology: Myasthenia Gravis