Myasthenia Gravis

Myasthenia Gravis (MG) is an autoimmune neuromuscular disorder characterized by weakness and rapid fatigue of voluntary muscles. It is caused by a defect in the transmission of nerve impulses to muscles due to a malfunction in the immune system. Normally, the neurotransmitter acetylcholine binds to receptors on the muscle cells to stimulate contraction. In MG, antibodies mistakenly attack and destroy these acetylcholine receptors at the neuromuscular junction, diminishing the muscle's ability to contract.

The hallmark of MG is muscle weakness that increases during periods of activity and improves after rest. The disease can affect any voluntary muscle but commonly targets those that control eye movements, facial expression, chewing, swallowing, and speaking. In some cases, it may also affect limb muscles and those involved in breathing. Severity can vary widely; while some patients experience only ocular problems (ocular myasthenia), others may have widespread muscle weakness (generalized myasthenia gravis). Symptoms can fluctuate and are often aggravated by fatigue, illness, and stress. Diagnosis is typically made through a combination of clinical evaluation, blood tests for specific antibodies, electromyography, and imaging studies. Treatment aims to improve muscle function and may include medications, thymectomy (surgical removal of the thymus gland), and plasmapheresis or intravenous immunoglobulin for acute exacerbations.