What is myasthenia gravis?
Myasthenia gravis is a chronic autoimmune, neuromuscular disease that causes weakness in the skeletal muscles that worsens after periods of activity and improves after periods of rest. These muscles are responsible for functions involving breathing and moving parts of the body, including the arms and legs.
The name myasthenia gravis, which is Latin and Greek in origin, means “grave, or serious, muscle weakness.” There is no known cure, but with current therapies, most cases of myasthenia gravis are not as “grave” as the name implies. Available treatments can control symptoms and often allow people to have a relatively high quality of life. Most individuals with the condition have a normal life expectancy.
What are the symptoms of myasthenia gravis?
The hallmark of myasthenia gravis is muscle weakness that worsens after periods of activity and improves after periods of rest. Certain muscles such as those that control eye and eyelid movement, facial expression, chewing, talking, and swallowing are often (but not always) involved in the disorder.
The onset of the disorder may be sudden, and symptoms often are not immediately recognized as myasthenia gravis. The degree of muscle weakness involved in myasthenia gravis varies greatly among individuals.
People with myasthenia gravis may experience the following 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.
Sometimes the severe weakness of myasthenia gravis may cause respiratory failure, which requires immediate emergency medical care.