Li Mao, Wang Zhan-jun, Cui Fang, Yang Fei, Chen Zhao-hui, Ling Li, Huang Xu-sheng
Department of Neurology, Chinese PLA General Hospital, Beijing, China.
Zhonghua Yi Xue Za Zhi. 2013 Jan 29;93(5):345-7.
To explore the electromyography (EMG) and nerve conduction (NC) features of patients with myotonic dystrophy type 1 (DM1).
Routine PCR and triplet primed-PCR (TP-PCR) were performed for 33 clinically diagnosed DM1 cases at our clinic from June 2009 to June 2012. The EMG and NC results of 30 patients with a genetic diagnosis of DM1 were collected and analyzed.
Myotonic discharges were found in all patients and EMG revealed myogenic changes in 29 patients. Among all 123 muscles examined, the incidence of myotonic discharges was, a little higher than that of myogenic changes (91.87% vs 90.24%). The rate of myotonic discharges in distal muscles was higher than that of myotonic discharges in proximal muscles (100% vs 83.61%). And the difference was statistically significant. No difference existed in myogenic changes between distal and proximal muscles.(87.10% vs 93.44%) Nerve conduction was all normal.
Myotonic discharges and myogenic changes are important EMG features in DM1. In early stage of DM1, myotonic discharges may be the isolated EMG abnormality. Myotonic discharges are predominantly detected in distal muscles. The involved regions detected by EMG are wider than those of clinical findings. EMG is an important screening tool for subclinical or early atypical DM1 patients.
探讨1型强直性肌营养不良（DM1）患者的肌电图（EMG）和神经传导（NC）特征。
对2009年6月至2012年6月在我院门诊临床诊断为DM1的33例患者进行常规PCR和三联体引物PCR（TP-PCR）检测。收集并分析30例基因诊断为DM1患者的EMG和NC结果。
所有患者均发现肌强直放电，29例患者EMG显示肌源性改变。在所有检测的123块肌肉中，肌强直放电的发生率略高于肌源性改变（91.87%对90.24%）。远端肌肉的肌强直放电率高于近端肌肉（100%对83.61%），差异有统计学意义。远端和近端肌肉的肌源性改变无差异（87.10%对93.44%）。神经传导均正常。
肌强直放电和肌源性改变是DM1重要的EMG特征。在DM1早期，肌强直放电可能是孤立的EMG异常。肌强直放电主要在远端肌肉检测到。EMG检测到的受累区域比临床表现的更广泛。EMG是亚临床或早期非典型DM1患者的重要筛查工具。
