The right answer is A.myasthenia gravis
Myasthenia gravis is an autoimmune disease affecting mainly young women and the elderly and whose incidence tends to increase. It affects neuromuscular junctions. A fluctuating oculo-facio-bulbar paresis of variable severity is frequent. Remissions and exacerbations are typical. The disease is caused by autoantibodies to acetylcholine receptors or, more rarely, to a specific muscle kinase.
Complementary examinations aim to confirm the diagnosis and to look for associated pathologies (1/10 to a thymoma or an associated autoimmune disease).
