Concurrence of myasthenia gravis and chorée fibrillaire de Morvan.

A case of myasthenia gravis associated with a syndrome resembling "chorée fibrillaire de Morvan" is described. This association has not been previously noted in the literature. It is postulated that this syndrome, when associated with myasthenia gravis, suggests an autoimmune pathogenesis, but prednisolone and plasmapheresis did not alter the symptoms. This case illustrates the fact that a separate entity should be considered when the clinical picture is not compatible with the underlying diagnosis.