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Updated: Nov 12, 2025
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Immunolabelling Myofiber Degeneration in Muscle Biopsies
Published on: December 5, 2019
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[Myasthenia gravis and muscle atrophy]
1Moscow Myasthenic Center of the City Clinical Hospital No. 51, Moscow, Russia.
Zhurnal Nevrologii I Psikhiatrii Imeni S.S. Korsakova
|March 17, 2021
Summary
Muscle atrophy is rare in myasthenia gravis, even in AChR-positive cases. This study suggests that observed muscle atrophy in these patients may stem from co-occurring neuromuscular diseases, not myasthenia gravis itself.
Area of Science:
- Neurology
- Clinical Medicine
Background:
- Muscle atrophy is an infrequent manifestation in myasthenia gravis (MG).
- While reported in MUSK-positive MG, its association with acetylcholine receptor (AChR)-positive MG is less understood.
Purpose of the Study:
- To investigate the occurrence and characteristics of muscle atrophy in patients with AChR-positive myasthenia gravis.
- To differentiate the cause of muscle atrophy in these patients.
Main Methods:
- Case series analysis of eight patients with AChR-positive myasthenia gravis and muscle atrophy.
- Clinical examination, quantitative electromyography, repetitive nerve stimulation, and MRI of the cervical spine.
- Exclusion of other neuromuscular diseases, neuropathies, and amyotrophic lateral sclerosis.
Main Results:
- Symmetrical forearm atrophy (six cases) and scapular winging (two cases) were observed.
- Atrophy onset occurred 3-18 years post-MG diagnosis, stabilizing after progression.
- Patients exhibited normal creatine phosphokinase (CPK) levels, no pain, sensory loss, or significant MRI abnormalities.
Conclusions:
- Muscle atrophy in these AChR-positive myasthenia gravis patients is unlikely a direct symptom of MG.
- The findings suggest an alternative underlying neuromuscular condition is responsible for the observed atrophy.
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