Myasthenia Gravis - MG

Myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction characterized by weakness of voluntary muscles, including the ocular, facial, oropharyngeal, limb, and respiratory muscles. MG can be broadly characterized as either ocular MG (a form of the disease that is limited to the eyelid and extraocular muscles) or generalized MG (MG that commonly involves ocular weakness as well as a variable combination of weakness in the bulbar, limb, and respiratory muscles). Clinical and serologic testing can be used to diagnose MG, but diagnostic sensitivity varies depending on whether the patient has ocular or generalized MG.  Demonstration of acetylcholine receptor (AChR) binding antibodies, which are present in the majority of patients with generalized disease, provides laboratory confirmation of MG. If AChR testing is negative, muscle-specific tyrosine kinase (MuSK) antibody testing should be performed. Because thymic abnormalities are not uncommon in individuals with MG, imaging and neurophysiologic studies may also be part of the initial evaluation.  

Tabs Content
Content Review: 
April 2019

Last Update: August 2019