• Annals of Clinical Neurophysiology
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• v.3 no.1
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• pp.1-8
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• 2001

The distal myopathies(DM) are clinically defined as inherited or sporadic primary muscle disorders characterized by progressive muscular weakness and atrophy beginning in the hands or feet and pathologically by myopathic changes in skeletal muscles. The pathologic changes are somewhat similar to those seen in chronic muscular dystrophy, but necrotic and regenerative processes are less prominent and creatine kinase levels are either normal or only mildly elevated. The most representative diseases are dominantly inherited Welander distal myopathy and tibial muscular dystrophy, and the recessively inherited distal myopathy with rimmed vacuoles and distal muscular dystrophy(Miyoshi myopathy). At present, further study is necessary to determine why rimmed vacuoles are so common in the DM, and what role they play in the pathogenesis of muscle fiber atrophy and loss, predominantly in the distal portions of the extremities.

• Annals of Clinical Neurophysiology
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• v.18 no.1
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• pp.31-33
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• 2016

• Annals of Clinical Neurophysiology
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• v.21 no.2
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• pp.79-86
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• 2019

Background: Magnetic resonance (MR) images are useful for diagnosing myopathy. The purpose of this study was to determine the usefulness of lower-limb MR images in Korean patients with distal myopathy. Methods: We reviewed medical records in the myopathy database from January 2002 to October 2016. We selected 21 patients from 91 unrelated families with distal myopathy: four with GNE myopathy, 11 with dysferlinopathy, and six with ADSSL1 myopathy. Results: Ten (48%) of the 21 patients were men. The ages of the participants at symptom onset and imaging were $19.2{\pm}9.5$ and $30.4{\pm}9.0$ years (mean${\pm}$standard deviation), respectively. Their grade on the modified Gardner-Medwin and Walton grade was $3.3{\pm}1.7$. The strength grade of the knee extensors was not correlated with the Mercuri scale for the quadriceps (r = -0.247, p = 0.115). However, the Medical Research Council grades of the knee flexors, ankle dorsiflexors, and ankle plantar flexors were significantly correlated with the Mercuri scale ratings of the knee flexors (r = -0.497, p = 0.001), tibialis anterior (r = -0.727, p < 0.001), and ankle plantar flexors (r = -0.620, p < 0.001), respectively. T1-weighted MR images showed characteristic fatty replacement patterns that were consistent with the causative genes. Unsupervised hierarchical clustering of the Mercuri scale showed that the main factors contributing to the dichotomy were the causative gene and the clinical severity. Conclusions: This study is the first to reveal the usefulness of lower-limb MR images in the differential diagnosis of distal myopathy in Korea.