Structural changes and contractility in muscle assessed by magnetic resonance imaging in individuals with ryanodine receptor 1-related rhabdomyolysis or myalgia.
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引用次数: 0
Abstract
Introduction/aims: Ryanodine receptor 1 (RYR1)-related myopathies associated with variants in the RYR1 gene present with a wide range of symptoms and severity. Two of the milder phenotypes associated with dominant pathogenic variants in RYR1 are rhabdomyolysis and myalgia. Only a few studies have investigated the muscle function and structure of individuals with RYR1-related rhabdomyolysis/myalgia objectively, showing inconsistent results. This study aimed to describe structural changes and contractility of muscles in individuals with RYR1-related rhabdomyolysis/myalgia.
Methods: We investigated 15 individuals with dominant variants in the RYR1-gene and compared them with 15 age-, sex-, and body mass index (BMI)-matched controls using MRI, stationary isokinetic dynamometry, and comprehensive clinical evaluation.
Results: No significant differences were found between individuals with RYR1-related rhabdomyolysis/myalgia and healthy controls in peak torque, fat fraction, cross-sectional area, contractile cross-sectional area, or contractility (p > .05) in muscles of the lower back (MRI data only), thigh, or calf. On clinical examination, three individuals exhibited weakness in hip or back extension on the Medical Research Council (MRC) test and eight had muscle hypertrophy. Individuals with weakness were not hypertrophic.
Discussion: Most individuals with RYR1-related rhabdomyolysis/myalgia have close to normal strength, and normal fat fraction and contractility of muscles, and therefore constitute a mild phenotype of RYR1-related myopathies.
期刊介绍:
Muscle & Nerve is an international and interdisciplinary publication of original contributions, in both health and disease, concerning studies of the muscle, the neuromuscular junction, the peripheral motor, sensory and autonomic neurons, and the central nervous system where the behavior of the peripheral nervous system is clarified. Appearing monthly, Muscle & Nerve publishes clinical studies and clinically relevant research reports in the fields of anatomy, biochemistry, cell biology, electrophysiology and electrodiagnosis, epidemiology, genetics, immunology, pathology, pharmacology, physiology, toxicology, and virology. The Journal welcomes articles and reports on basic clinical electrophysiology and electrodiagnosis. We expedite some papers dealing with timely topics to keep up with the fast-moving pace of science, based on the referees'' recommendation.