RESUMO
@#To summarize characteristics of the clinical manifestation，pathology and lower limb muscle magnetic resonance imaging in 11 patients diagnosed as myotonic dystrophy 1.Methods Eleven patients with myotonic myopathy 1，who were admitted to Nanjing Drum Tower Hopsital from January 2012 to October 2020，were chosen in our study. All patients accepted clinical examination，skeletal muscle biopsy，and 5 of them received lower limb muscle magnetic resonance imaging （MRI）. Clinical data were collected for retrospective analysis.Results All 11 patients were observed muscle myotonia，weakness or amyotrophy to some extent and the latter two symptoms were more serious in distal limb than in proximal. Under the light microscopy，type I filber atrophy in ten cases，nucleus moving inward，nucleus gathering and sarcoplasmic masses in some cases were found.That fatty infiltration appears asymmetrical distribution and more serious in distal limb compared with the proximal limb in five cases was observed by MRI. Among lower limbs，vastus medialis，vastus lateralis，vastus intermedius，tibialis anterior，gastrocnemius，soleus muscles were the most severely affected.Conclusion Muscle magnetic resonance imaging examination is a trustworthy method for definite diagnosis of myotonic myopathies.