Introduction
Myasthenia Gravis is an autoimmune disease that causes weakness in skeletal muscles. Skeletal muscles facilitate movement and are the largest muscle fibers in the human body. This condition causes muscles under voluntary control to feel weak and quickly tired. While both men and women can get affected by myasthenia gravis, women are 3 times more likely to develop MG before the age of 40.
Causes
Myasthenia Gravis occurs when your body’s immune system mistakenly attacks itself. MG causes the immune system to make antibodies that block/destroy muscle receptor sites for a neurotransmitter called acetylcholine. When there is a bare minimum of receptor sites, muscles receive fever nerve signals, which causes weakness. Additionally, some antibodies can have a protein muscle-specific receptor tyrosine kinase (MuSk). MuSk aids in forming the nerve-muscle junctions. Antibodies that oppose this protein can lead to myasthenia gravis.
Symptoms
Droopy eyelids
Muscle weakness in the arms, legs, neck, hands, and fingers
Chewing and Swallowing problems
Slurred speech
Difficulty making facial expressions
Double vision
Complications
People diagnosed with myasthenia gravis are usually very weak and feel fatigued. This can cause stress as well as depression. Additionally, 1 in people experience a serious complication called myasthenic crisis. It is a condition that causes the muscles that control breathing to become too weak to function, leading to respiratory failure. Furthermore, some people with MG have tumors in their thyroid gland. However, most thyroid tumors aren’t cancerous.
Diagnosis
To diagnose myasthenia gravis, healthcare professionals perform a physical examination; doctors assess muscle strength and check for signs of muscle fatigue, particularly in the eyes and face. If there are abnormal signs in the physical examination, blood tests are conducted to detect the presence of specific antibodies such as anti-acetylcholine receptor (AChR) or anti-MuSK antibodies. After this, an EMG will be used to assess the electrical activity of muscles and nerves. Additionally, imaging tests like an MRI or CT scan are utilized to check for thymus gland tumors which are associated with myasthenia gravis.
Treatment
Currently, there is no cure for myasthenia gravis, but treatments such as medications, and ACHE inhibitors can alleviate the condition. Acetylcholinesterase inhibitors like pyridostigmine can increase the levels of acetylcholine at the neuromuscular junction which improves muscle contraction. Immunosuppressive drugs such as corticosteroids can be used to reduce the immune system’s attack on the body’s tissues. In severe cases of MG, intravenous immunoglobulin (IVIg) therapy or plasmapheresis is utilized to remove harmful antibodies from the blood plasma and replace them with a plasma solution.
References
https://www.mayoclinic.org/diseases-conditions/myasthenia-gravis/symptoms-causes/syc-20352036
https://my.clevelandclinic.org/health/diseases/17252-myasthenia-gravis-mg