Abstract Details

Title Rippling Muscle as an Isolated Symptom of Antibody Positive Myasthenia Gravis: Case Report

Topic Neuromuscular and Clinical Neurophysiology (EMG)

Presentation(s) P2 - Poster Session 2 (11:45 AM-12:45 PM)

Poster/Presentation
Number 9-002

Objective To describe a case of isolated muscle rippling as the sole manifestation of antibody-positive myasthenia gravis (MG) confirmed by single-fiber electromyography (SFEMG).

Background

Rippling muscle disease can be hereditary or immune-mediated, with the latter associated with myasthenia gravis. Muscle rippling without muscle weakness or fatigue has not been well characterized in the literature.

Immune mediated muscle rippling disease (iRMD) with myasthenia gravis (MG) was first reported in the 1990s by Drs. Ansevin and Agamanolis. Since the initial description, more publications have described an association between iRMD and MG with or without thymoma or positive serum acetylcholine receptor (AChR) antibodies. Cases have been published describing alleviation of muscle rippling correlating with remission of myasthenic symptoms with proper immunotherapy. To our knowledge, isolated muscle rippling as the initial and sole manifestation of MG has not previously been reported.

Design/Methods Clinical, serologic, and electrodiagnostic evaluations were performed in a patient presenting with isolated muscle rippling. SFEMG was used to assess neuromuscular transmission. A literature review was conducted to examine proposed mechanisms linking immune-mediated RMD and MG.

Results A 59-year-old male presented with 6 months of odd sensations, spontaneous movements of muscles, and elevated serum creatinine kinase. These movements were described as waves across his thighs and calves with activation and subsequent relaxation. He denied any weakness, eyelid drooping, double vision, or speech changes. Genetic testing, including the CAV3 gene, was negative. He was found to have positive AChR antibodies. He also had an EMG capturing these muscle movements, that were shown to be electrodiagnostically silent. Subsequent single-fiber EMG showed mildly abnormal jitter consistent with MG. Chest CT did not reveal evidence of a mediastinal mass.

Conclusions Muscle rippling is a rarely associated finding in myasthenia gravis. In isolation, it should be considered as an early presenting sign of MG, prompting workup including AChR antibody testing and EMG.

Authors/Disclosures
Colin Fry, MD PRESENTER	Dr. Fry has nothing to disclose.
Rabia Malik, MD (Rush University Medical Center)	Dr. Malik has nothing to disclose.

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