Neuromuscular Disorders

Myasthenia Gravis

Myasthenia gravis is a rare autoimmune disorder that causes muscle weakness due to a problem at the neuromuscular junction. It is a chronic illness in which the body's immune system produces antibodies against the chemicals (neurotransmitters such as acetylcholine) which initiate nerve impulses. Normally, they would trigger muscle contraction; however, in myasthenia gravis patients, it leads to skeletal muscle weakness and fatigue, which is worsened with physical exertion. Although myasthenia gravis can affect any muscle, the most affected group of muscles remains those innervated by cranial nerves (nerves that emerge from brain and innervate parts of face, lips, tongue, neck, and throat). Other symptoms include weakness and difficulty in controlling muscles of eyes, mouth, arms, hands, legs, and fingers.

These early symptoms of muscle weakness may get better with proper rest; nevertheless, if they continue to occur, it may give rise to serious paralysis due to loss of muscle function. Weakness in respiratory muscles can lead to life-threatening breathing problems. Stress, changes in temperature, and infections can add on to pain in some cases. Currently, there is no cure for myasthenia gravis, but providing care with appropriate treatment can help alleviate the painful symptoms. Doctors usually treat myasthenia gravis by prescribing anticholinestrase drugs, corticosteroids, or immune-suppressing drugs that reduce inflammation and inhibit the immune response. Alternatively, a physician may offer surgery to remove the thymus gland, as the thymus gland is part of an immune system that is thought to be linked with the sickness caused by myasthenia gravis. Women younger than 40 years are most susceptible to develop this disorder, but in general, myasthenia gravis can occur [Page 1233]at any age, particularly when derived from a tumor. About 20 percent of mothers suffering from myasthenia gravis are at risk of transmitting the disease to their newborns.