Expired CME Article

Myasthenia Gravis Crisis

Authors: Eric M. Bershad, MD, Eliahu S. Feen, MD, Jose I. Suarez, MD

Abstract

Myasthenia gravis (MG) is an autoimmune disorder resulting from the production of antibodies against acetylcholine receptors leading to the destruction of the postsynaptic membrane at the neuromuscular junction. In the US there are about 18,000 people with MG. Myasthenia gravis crisis (MGC) is defined as any MG exacerbation necessitating mechanical ventilation. Most patients presenting with MGC have an identifiable risk factor. The diagnosis of MGC should be suspected in all patients with respiratory failure, particularly those with unclear etiology. Acute management of MGC requires supportive general and ventilatory therapy and institution of measures to improve the neuromuscular blockade. The latter includes plasma exchange or IV immunoglobulin, and removal of the offending trigger. The outcome of patients with MGC has improved significantly and the current mortality rate is about 4 to 8%.


Key Points


* Myasthenia gravis crisis (MGC) is defined as any myasthenia gravis (MG) exacerbation necessitating mechanical ventilation.


* About 15–20% of patients with myasthenia gravis will experience MGC, typically within the first 2 years of MG diagnosis.


* Most patients with myasthenia gravis crisis have an identifiable precipitating event; however in 30–40% of patients, no triggering factor is found.


* Plasma exchange or intravenous immunoglobulins are indicated to help facilitate recovery of neuromuscular blockade.


* The overall outcome for patients with myasthenia gravis crisis is excellent if therapeutic and supportive measures are instituted promptly.

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