Myasthenia Gravis – An Updated Review

Myasthenia gravis (MG) is an autoimmune neuromuscular junction (NMJ) disorder characterized by fatigable weakness in skeletal and ocular muscles. The etiology is the presence of autoimmune antibodies against postsynaptic acetylcholine receptors (AChR) or other muscle-specific proteins. The result is muscle end plate dysfunction and weakness. While symptoms may be limited to ocular muscles (ocular MG/OMG), systemic generalization of symptoms (generalized MG/gMG) can frequently occur. Diagnosis relies on a history of fluctuating weakness, diurnal variation in muscle strength, physical examination signs of fluctuating muscle weakness, supported by serology and electrophysiologic studies. In its most severe form, called myasthenic crisis, weakness can involve respiratory muscles, and can cause life-threatening hypoxemia needing critical care monitoring and invasive ventilation. Management of MG is multimodal and may need a combination of acetyl cholinesterase inhibitors, immunomodulators such as steroids, and steroid-sparing agents, intravenous agents, such as intravenous immunoglobulin, or plasma exchange, rarely needing surgical options such as thymectomy. Recent advances have added novel therapeutics as viable treatment options.