Is myasthenia gravis caused by herpes?

Myasthenia gravis is not caused by herpes. Myasthenia gravis is a neuromuscular disease caused by a defect in the transmission of nerve impulses to the muscles. The most common cause of myasthenia gravis is an autoimmune reaction in which the body produces antibodies that block or destroy the receptors for acetylcholine, a neurotransmitter that is essential for muscle contraction. Other causes include certain medications, infections, and thymoma, a tumor of the thymus gland. Herpes is a group of viral infections that can cause a variety of symptoms, depending on the type of herpes virus.