Neuromuscular transmission abnormalities in myotonic dystrophy type 1: A neurophysiological study

Objectives: Weakness and fatigue are frequent symptoms in myotonic dystrophy type 1 (DM1), mainly as a result of muscle impairment. However, neuromuscular junction (NMJ) abnormalities could play an additional role in determining these manifestations. We aimed to document the possible NMJ involvement in DM1.Patients and methods: In order to substantiate this hypothesis we performed low rate repetitive nerve stimulation (RNS) and single fiber electromyography (SFEMG), in 14 DM1 subjects.Results: RNS resulted abnormal in four patients while SFEMG revealed a pathological jitter in ten. A significative correlation was found between jitter values and decrementing response (p < 0.000311; r= 0.822).Conclusion: These results suggest a possible involvement of NMJ in DM1. (C) 2016 Elsevier B.V. All rights reserved