Myasthenia Gravis Disease
What is Myasthenia Gravis Disease?
Myasthenia Gravis is an uncommon, chronic autoimmune disease. It is characterized by fluctuating levels of muscle weakness. MG affects only a small number of people, about 15 per 100,000 individuals. While Myasthenia Gravis is a rare condition, it can be a very serious condition.
What Causes Myasthenia Gravis Disease?
Myasthenia Gravis occurs when the body's immune system over-actively produces antibodies against a particular target in the person's own body. Antibodies are normally made by a person's immune system in response to a virus or other foreign body. In the case of Myasthenia Gravis, however, antibodies attack a normal component of a person's body.
What are the Risk Factors for Developing Myasthenia Gravis Disease?
A family history of autoimmune diseases, such as diabetes or thyroid disease, puts a person at an increased risk of developing Myasthenia Gravis. The disease can develop at any age and affects all races.
What are the Symptoms of Myasthenia Gravis Disease?
Symptoms of Myasthenia Gravis may include:
•Fatigable muscle weakness
•Difficulty with speech, smiling, chewing and swallowing
•Difficulty holding head upright
•Difficulty walking upstairs or holding arms up
•Shortness of breath while exercising or lying down
Some patients only experience symptoms affecting their eye muscles. This is called ocular Myasthenia Gravis. Two thirds of all Myasthenia Gravis patients initially present with affected eye muscles. Other patients may experience fatigable muscle weakness in other areas of the body. Fatigable muscle weakness is characterized by weakness of voluntary muscles that becomes worse with repeated use of the muscle. The weakness is not usually accompanied by any pain.
Symptoms of Myasthenia Gravis can fluctuate a great deal. They are usually worse towards the latter part of the day, during hot weather, during or after a recent infection, or, for women, just before a period.
How is Myasthenia Gravis Disease Diagnosed?
Myasthenia Gravis is diagnosed using the following methods:
•Chest CT scan
•Tensilon test: This involves the injection of Edrophonium and, in many patients, results in the short-lived improvement of symptoms.
How is Myasthenia Gravis Disease Treated?
There are several treatment options for Myasthenia Gravis. They include:
•Anticholinesterase Medication: Pyridosigmine (Mestinon) is the most common anticholinesterase. Benefits usually occur within an hour but only last three to four hours so medication must be taken at regular intervals throughout the day for maximum benefits.
•Thymectomy: This is the surgical removal of the thymus. One in four people are cured by thymectomey, one in two show a significant improvement and one in four do not show any improvement.
•Steroids: Steroid treatment can be very effective but there may be several side effects including: osteoporosis.
•Steroid-sparing agents: These may be used as an alternative to steroid treatment to reduce the risk of unwanted side-effects.
What is the Prognosis for Patients with Myasthenia Gravis Disease?
The use of steroids and steroid-sparing agents as a treatment for Myasthenia Gravis has significantly improved the prognosis for patients. Adequate doses of these medications usually result in a patient's total lack of symptoms. Most patients, however, must continue to take the medication indefinitely as symptoms almost always return if medication is discontinued.