Autoimmune diseases are those where the body’s own immune system starts attacking cells and organs within the body. One such disease that affects the neuromuscular system is myasthenia gravis.
What is myasthenia gravis?
Myasthenia gravis is a condition that causes muscle weakness and extreme fatigueness. This disease is characterized by weakening of the voluntary muscles. These muscles include the eye muscles that control the eye and eyelid movement; facial muscles that help chew, talk, swallow and provide facial expressions; muscles that help in breathing; muscles that help in moving the neck and the limbs, etc. The disease can affect any person in any age group. The prognosis of the disease is now better with the availability of newer treatment methods. Thus, giving people suffering from myasthenia gravis a chance to live near normal lives.
What are the symptoms of myasthenia gravis?
When one starts using a certain muscle repeteadly, it leads to flaring up of the myasthenia gravis symptoms. With rest, the symptoms tend to subside.
The common symptoms of myasthenia gravis are as follows:
- The first muscles to be affected by the disease are generally the muscles of the eye. This causes drooping of one or both eyelids and double vision.
- Next, are the muscles of the face that leads to limitations of facial expressions. One may have difficulty smiling and expressing other emotions on their face.
- The throat muscles are also affected and cause problems with speech (often nasal), chewing as well as swallowing.
- As the disease progresses, it will affect muscles in the neck, arms and legs. Thus, some may find it difficult to hold their head straight due to weakened neck muscles. Some may find holding or grabbing on to things difficult due to weak arm muscles. Loss of balance, uncoordinated gait or waddling when walking is a sign of weak leg muscles.
- Breathing may be affected leading to shortness of breath.
- A condition called as myasthenic crisis may strike some patients. In this, the respiratory muscles are affected leading to their sudden paralysis. The person finds breathing extremely difficult and should be immediately put on assisted ventilation to prevent death.
What causes myasthenia gravis?
The immune system of the body starts blocking the acetylcholine receptors present at the neuromuscular junction. The antibodies that attack acetylcholine are thought to be produced by the thymus gland. The attack by the antibodies destroys the cells and prevents the muscles from communicating with each other leading to muscle weakness. The reason why the immune system starts attacking the muscle cells is unknown.
How is myasthenia gravis diagnosed?
There are many symptoms of myasthenia gravis that are similar to other conditions. Also, many times the symptoms are so mild, that it becomes difficult to diagnose myasthenia gravis. In this case, a complete medical history of the patient along with neurological examination is carried out. Different tests are ordered to draw conclusion whether the patient is suffering from myasthenia gravis.
Some of the tests include:
- Electromyography (EMG)
- Tensilon test
- CT Scan
- Ice test
- Edrophonium test
- Magnetic resonance imaging (MRI)
- Pulmonary function test
- Blood tests to check antibodies against acetylcholine receptors, etc.
Treatment for myasthenia gravis
Management of myasthenia gravis is carried out with the help of medication and surgery.
The medications that help provide relief to the symptoms include:
- Acetylcholinesterase inhibitors that help in improving the weak muscle functions
- Immunosuppressive drugs that help control the immune system from attacking the muscle cells.
Surgical treatment includes thymectomy, that is, surgical removal of the thymus gland. In some patients, plasmapheresis is considered as an option to filter out the antibodies attacking and destroying acetylcholine.
Prognosis of myasthenia gravis
The prognosis for myasthenia gravis is good. With proper treatment, many patients show improved muscle strength. Most patients undergo a temporary remission phase. A few may even have a permanent remission, especially after thymectomy. However, one should keep in mind there is no cure for myasthenia gravis.
The symptoms may vary throughout life, but following proper treatment will help one live a near normal life.
Written by: healthplus24.com team
Date last updated: december 29, 2014