Myasthenia Gravis
Myasthenia gravis is a neuromuscular disease that results in fluctuating muscle weakness and fatigue. The initial symptom of myasthenia gravis is that of a painless weakness in specific muscles. This weakness becomes progressively worse during physical activity, yet improves after resting. Myasthenia gravis is caused by variations in specific genes, which result in transmission defects in nerve impulses in the muscles.
Often, myasthenia gravis begins as eye weakness before progressing to a more severe, generalized bodily weakness. About two-thirds of patients with myasthenia gravis initially present with eye weakness, possibly drooping eyelids or double vision. These symptoms progress when reading, driving, or watching television, and wearing sunglasses may help initially.
Diagnosis of myasthenia gravis can be difficult. It remains quite rare, with between 3 and 30 people per million diagnosed annually. Once a person is diagnosed, there is a five-stage classification of a person's neurological status. This scale ranges from the mild, eye weakness, to the severe, in which intubation is required in order to maintain the person's airway. Suspected diagnosis is followed by a blood test.
Management of myasthenia gravis consists of medication and possibly surgery. The most common medications include the following:
- Acetylcholinesterase inhibitors, which improve muscle function
- Immunosuppressant drugs, which combat the autoimmune impairment