Myasthenia Gravis

Myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction caused by autoantibodies against acetylcholine receptors (AChR) or muscle-specific kinase (MuSK). These antibodies bind to and destroy receptors, reducing the efficiency of neuromuscular transmission. The result is muscle weakness that worsens with exertion and improves with rest. Symptoms are highly variable, ranging from isolated ocular symptoms (eyelid drooping, diplopia) to generalized weakness affecting proximal limb muscles, bulbar muscles (affecting speech and swallowing), and respiratory muscles. Approximately 15-20% of patients develop myasthenic crisis, a life-threatening condition involving respiratory muscle paralysis. Diagnosis involves clinical assessment, antibody testing (anti-AChR or anti-MuSK), electromyography, and response to edrophonium or neostigmine. Treatment options include acetylcholinesterase inhibitors, immunosuppressive medications, and newer biologic therapies targeting B cells and complement.