Diagnosis and evaluation of myasthenia gravis

The diagnosis of MG is made in patients with clinical evidence of neuromuscular weakness and confirmatory serologic or electrodiagnostic testing. Patients who are diagnosed with MG should also be evaluated for thymic abnormalities and associated autoimmune thyroid disease.

AChR: acetylcholine receptor; CT: computed tomography; EMG: electromyography; LRP4: low-density lipoprotein receptor-related protein 4; MG: myasthenia gravis; MRI: magnetic resonance imaging; MuSK: muscle-specific tyrosine kinase; NCS: nerve conduction study; RNS: repetitive nerve stimulation; SFEMG: single fiber electromyography.

* The detection of low-titer positive results is of uncertain significance; additional confirmatory testing is warranted.

¶ Refer to UpToDate topic for additional details on the differential diagnosis of MG.

Δ SFEMG is performed by experienced electromyographers when the diagnosis is uncertain after NCS with RNS and standard EMG testing. Refer to UpToDate topic for additional details on the diagnosis of MG.

◊ Patients with MuSK-positive MG do not typically require mediastinal imaging because thymomas and other thymic abnormalities are not associated with MuSK autoantibodies.

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خرید پکیج

Diagnosis and evaluation of myasthenia gravis