Myasthenia gravis involves episodic muscle weakness and easy fatigability caused by autoantibody- and cell-mediated destruction of acetylcholine receptors. It is more common among young women but may occur in men or women at any age. About 10% of patients with myasthenia gravis also have a thymoma; about half of the thymomas are malignant. Symptoms worsen with muscle activity and lessen with rest. Diagnosis is by measurement of serum acetylcholine receptor (AChR) antibody levels, electromyography, and sometimes IV edrophonium challenge, which briefly lessens the weakness. Treatment includes anticholinesterase drugs, immunosuppressants, corticosteroids, plasma exchange, IV immune globulin, and possibly thymectomy.
See See myasthenia gravis for more details in The Manuals.
References:
Oger J, Frykman H:An update on laboratory diagnosis in myasthenia gravis. Clin Chim Acta444:126–131, 2015. doi: 10.1016/j.cca.2015.01.042.
Berrih-Aknin S, Frenkian-Cuvelier M, Eymard B: Diagnostic and clinical classification of autoimmune myasthenia gravis. J Autoimmun 48–49:143–148, 2014. doi: 10.1016/j.jaut.2014.01.003.