Context and Definition
Myasthenia gravis (MG) is a complex disease with many different signs and symptoms, which may be obvious or subtle.
It can cause a life-threatening true neurological emergency characterised by impending respiratory failure. The emergency physician (EP) should be able to promptly recognize, appropriately investigate and initiate treatment when faced with such a crisis
Definition
The name myasthenia gravis, which is Greek in origin, means ‘grave muscle weakness’.
MG is the most common neuromuscular junction (NMJ) disorder. It is an autoimmune disease caused by antibodies to the acetylcholine receptor on the postsynaptic membrane at the NMJ.
MG is characterised by weakness and fatigability of the voluntary muscles.
The annual incidence of MG ranges from approximately 7 to 23 new cases per million.
All ethnic groups and all ages may be affected.
It has a bimodal peak of incidence with the first peak in the third decade and the second peak in the sixth decade (‘young women and old men’).
It is probably under diagnosed in the elderly population.