Abstract: Objective  To study the clinical characteristics, electromyogram, muscle pathology and diagnostic methods of myotonic dystrophy (DM).Methods  This paper summarized the clinical characteristics, electromyogram and muscle pathology of 5 patients who were clinically diagnosed with myotonic dystrophy in hospital from 2008 to 2011.Results  Electromyogram and muscle pathology were performed in all 5 patients. Myogenic lesions and tonic potential were found in the electromyogram of 5 patients. The pathological findings of muscle pathology in 5 patients were consistent with the pathological manifestations of tonic muscle dystrophy. Conclusion  DM patients can be diagnosed according to their clinical characteristics, electromyogram examination and muscle pathology.

Key words: myotonic dystrophy, electromyogram；pathology