强直性肌营养不良1型患者的电生理特点

Electrophysiological features of patients with myotonic dystrophy type 1

目的探讨强直性肌营养不良1型（DM1）患者的肌电图及神经传导特点。方法初步选取解放军总医院神经内科门诊2009年6月至2012年6月临床拟诊为DMl的患者33例，采用常规PCR与三重引物PCR（TP-PCR）相结合的方法行基因诊断，回顾分析30例确诊为DM1患者的肌电图及神经传导资料。结果30例（100％）均有肌强直放电，29例（96．67％）有肌源性损害。所检123块肌肉中，113块（91．87％）有肌强直放电，111块（90．24％）有肌源性损害，肢体远端肌肉肌强直放电发生率（100％）高于近端肌肉（83．61％）（P〈0．05），远端肌肉肌源性损害发生率（87．10％）与近端肌肉（93．44％）差异无统计学意义。所有患者神经传导检测均正常。结论强直性肌营养不良1型患者肌电图以肌强直放电合并肌源性损害为主要特点，病程早期可仅有肌强直放电。肌强直放电主要分布于肢体远端肌肉。肌电图检出肌强直放电和肌源性损害的范围较临床表现更广泛，对于亚临床或病程较短的不典型患者，可作为重要的初筛工具。

Objective To explore the electromyography （EMG） and nerve conduction （NC） features of patients with myotonic dystrophy type 1 （ DM1 ）. Methods 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. Results 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. Conclusions 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.