How does thymectomy treat myastenia gravis?

Great question: There are many theories. It seems that although the thymus should involute, in patients with mg, it plays a role in production of antibodies that effect the interaction between acetylcholine and the motor endplates.

Removing a source: In select patients, a thymectomy may lead to a significant reduction in symptoms by removing the organ responsible for producing antibodies responsible for initiating symptoms. This works better in patients who have had some response to medical therapy, and who have an enlarged thymus gland, but this is not absolute. Before choosing this option, you should discuss this with your treating doctor.