Acquired rippling muscle disease with myasthenia gravis.

Rippling muscle disease (RMD) is a rare disorder that occurs in both familial and sporadic forms. Seven patients have previously been reported with myasthenia gravis and sporadic RMD. There have been conflicting reports of the electrophysiological characteristics of rippling muscles in this acquired form. Another such patient is reported, and the clinical, electrophysiological, and laboratory features of this disorder are described. In addition, this patient had alopecia areata and recurrent metastatic thymoma, years after resection of a benign thymoma. This report emphasizes the clinical manifestations of RMD in association with myasthenia gravis (RMD-MG), and its distinctive features, in this and previously reported patients.