Myasthenia gravis (MG) is an autoimmune disorder affecting the neuromuscular junction. Your immune system mistakenly attacks the receptors that allow muscle cells to receive signals from your nerves. This disruption causes muscle weakness and fatigue.
Understanding the Neuromuscular Junction
The neuromuscular junction is where nerve cells communicate with muscle cells. Acetylcholine, a neurotransmitter, carries the signal across this junction. In MG, antibodies block or destroy acetylcholine receptors, reducing the signal strength.
- Reduced acetylcholine receptor function leads to less effective muscle contraction. This weakness worsens with exertion and improves with rest. Symptoms are highly variable, ranging from mild to severely debilitating.
Common Symptoms and Diagnostic Considerations
MG symptoms vary greatly depending on which muscles are affected. Common symptoms include:
- Drooping eyelids (ptosis) Double vision (diplopia) Difficulty swallowing (dysphagia) Weakness in the limbs Difficulty breathing
Diagnosis involves a physical exam, blood tests to detect acetylcholine receptor antibodies, and electromyography (EMG) to assess muscle electrical activity. A Tensilon test, involving a short-acting acetylcholinesterase inhibitor, may also be used.
Treatment Approaches
Treatment goals focus on improving muscle strength and managing symptoms. Options include:
Medications: Cholinesterase inhibitors (like pyridostigmine) increase acetylcholine levels. Immunosuppressants (like corticosteroids, azathioprine, or mycophenolate mofetil) suppress the immune system’s attack. Thymectomy: Surgical removal of the thymus gland, which plays a role in the immune response in some MG cases, can be beneficial. Plasmapheresis: A procedure to remove harmful antibodies from the blood. This is often used for acute exacerbations. Intravenous immunoglobulin (IVIG): Infusion of antibodies to suppress the immune response.
Treatment plans are personalized based on symptom severity and individual response. Regular monitoring is crucial for managing the condition effectively.
