Comparative efficacy of repetitive nerve stimulation, exercise, and cold in differentiating myotonic disorders
Comparative efficacy of repetitive nerve stimulation, exercise, and cold in differentiating myotonic disorders
复制标题
DOI：
10.1002/mus.20856
复制
发表时间：
2007-11-01
期刊：
影响因子：
3.4
通讯作者：
Kuntzer, Thierry
中科院分区：
文献类型：
--
作者：
Michel, Patrik;Sternberg, Damien;Kuntzer, Thierry
复合肌动作电位（CMAP）对刺激试验的递减反应在基因证实的肌强直性疾病中没有特征。因此，我们研究了10例隐性先天性肌强直（rMC）患者、2例先天性肌副强直（PMC）患者、9例1型肌强直营养不良（DM1）患者、4例DM2患者和14名健康人的减量反应与突变类型的关系。cmap在休息时、短时间运动试验（SET）后以及短时间、5 hz和10 hz的重复神经刺激（RNS）训练（32℃和20℃）时测量，其下降程度与临床肌强直的严重程度无关。对照组和PMC患者在加热时有相似的反应，但在冷却时PMC患者的CMAPs持续下降。在rMC患者中，减少的反应与CLCN1基因突变的类型有关，因为在T268M， R894X, IVS17+ 1g b> T， K248X和2149 del G中会出现减少，但与IVS1 + 3a b> T， F167L或显性A313T突变无关。在DM1患者中，减量与CTG重复数之间没有关系。因此，肌强直肌膜部分不兴奋的程度取决于突变类型，而不是临床肌强直的程度。10 Hz的RNS比SET更敏感地显示rMC患者在温暖时的异常；寒冷时差异不太明显，这对诊断PMC很有用。因此，刺激试验在肌强直中是有用的，以证明肌肉的不兴奋性，这取决于氯或钠通道病。
The decremental response of the compound muscle action potential (CMAP) to provocative tests is not characterized in genetically verified myotonic disorders. We therefore studied the relationship between decremental responses and mutation type in 10 patients with recessive myotonia congenita (rMC), two with paramyotonia congenita (PMC), nine with myotonic dystrophy type 1 (DM1), four with DM2, and 14 healthy people. CMAPs were measured at rest, just after a short exercise test (SET), and during short, 5- and 10-Hz, repetitive nerve stimulation (RNS) trains at 32 degrees C and at 20 degrees C. The degree of decrement was not related to the severity of clinical myotonia. Controls and PMC patients had similar responses when warm, but with cooling PMC patients had a persistent decrement of CMAPs. In the rMC patients the decremental responses were related to the type of mutation of the CLCN1 gene, as a decrement was encountered in the T268M, R894X, IVS17+1 G > T, K248X, and 2149 del G, but not with the IVS1 + 3 A > T, F167L, or dominant A313T mutations. In DM1 patients there was no relationship between decrement and CTG repeats. The degree of partial inexcitability in myotonic muscle membrane therefore depends on the mutation type rather than degree of clinical myotonia. RNS at 10 Hz is more sensitive than SET for demonstrating abnormalities in rMC patients when warm; differences are less marked when cold, which is useful to diagnose PMC. Provocative tests are therefore useful in myotonias to demonstrate muscle inexcitability, which depends on the chloride or sodium channelopathy.