DISEASES
description
Myasthenia gravis (MG) is a neuromuscular disorder that causes weakness in the skeletal muscles which are the muscles your body uses for movement. It occurs when communication between nerve cells and muscles becomes impaired. This impairment prevents crucial muscle contractions from occurring, resulting in muscle weakness. Weakness associated with MG typically gets worse with more activity and improves with rest. Symptoms of MG can include trouble talking, problems walking upstairs or lifting objects, facial paralysis, difficulty breathing, difficulty swallowing or chewing, drooping of eyelids and double vision. Some people with MG have tumor of the thymus gland (thymoma).
The main test for MG is a blood test to detect the presence of an autoantibody that binds to the acetylcholine receptor (AchR) thus stopping signals being sent between the nerves and muscles. About 75 percent of patients with MG show an elevated amount of AchR antibodies in the blood. In one-third of MG patients with generalized weakness and without elevated acetylcholine receptor antibodies, muscle-specific tyrosine kinase (MuSK) antibody is increased, which can help with the diagnosis.
Symptoms
- Weakness of the eye muscles (called ocular myasthenia)
- Drooping of one or both eyelids (ptosis)
- Blurred or double vision (diplopia)
- A change in facial expression
- Difficulty swallowing
- Shortness of breath
- Impaired speech (dysarthria)
- Weakness in the arms, hands, fingers, legs, and neck