Rinsho Shinkeigaku (Clinical Neurology)

Brief Clinical Note

Rippling muscle disease with myasthenia gravis

Naohiro Fujita, M.D.1), Teruyuki Ishikura, M.D., Ph.D.1) Nozomi Nagashima, M.D.1), Akira Nishikawa, M.D.1), Hisae Sumi-Akamaru, M.D., Ph.D.1) and Takashi Naka, M.D., Ph.D.1)

1) Department of Neurology, Higashiosaka City Medical Center

In February 2020, a 51-year-old woman experienced leg myalgia and noticed calf muscle movements that resembled a rippling wave while crouching down. In June 2020, she complained of bilateral arm myalgia. In August 2020, she developed left ptosis, had difficulty raising her bilateral arms, and developed diplopia and was admitted to our hospital. Anti-acetylcholine receptor antibodies turned out to be positive. We made a diagnosis of myasthenia gravis and acquired rippling muscle disease (RMD). Her myasthenia gravis symptoms and myalgia decreased with oral prednisolone. Contrast-enhanced computed tomography revealed thymoma. She underwent extended thymectomy and was discharged from the hospital. Her myalgia worsened, but it was responsive to methylprednisolone pulse therapy. CAV3 gene mutations are recognized as causes of congenial RMD whereas acquired RMD is associated with myasthenia gravis. Acquired RMD is rarely reported in Japan, but should be kept in mind as a condition treatable with immunotherapy.
Supplemental video
Fig. 1 Rippling of the gastrocnemius.
The arrow indicates rippling muscle contractions in the gastrocnemius while the patient is crouching down.
Please watch the supplementary movie.
Full Text of this Article in Japanese PDF (929K)

(CLINICA NEUROL, 62: 563−566, 2022)
key words: rippling, RMD (rippling muscle disease), myasthenia gravis

(Received: 19-Jan-22)