Abstract：
BACKGROUND: In this study we evaluated the role of an electrodiagnostic provocative test (long exercise test) in McArdle disease.
METHODS: Twenty-five McArdle patients and 2 control groups underwent an electrodiagnostic protocol with long exercise test (LET), consisting of recording the compound muscle action potential (CMAP) before and after 5 minutes of isometric contraction.
RESULTS: The LET disclosed a postexercise decrease in CMAP amplitude in 23 of 25 McArdle patients. The immediate and long-lasting decrease differentiated McArdle patients from controls. Patients with a normal LET demonstrated milder symptoms and/or residual myophosphorylase activity.
CONCLUSIONS: The LET is a sensitive, safe, and noninvasive provocative test that may guide clinicians toward molecular analysis of the myophosphorylase gene. The abnormalities observed on LET point toward complex biochemical mechanisms determined by the absence of myophosphorylase, beyond simple glycolytic blockade (ionic pump dysfunction, sarcolemmal inexcitability). The normal LET in patients with milder symptoms indicates a relationship of the LET with clinical severity, thus identifying it as a potential outcome measure. Muscle Nerve, 2018.
METHODS: Twenty-five McArdle patients and 2 control groups underwent an electrodiagnostic protocol with long exercise test (LET), consisting of recording the compound muscle action potential (CMAP) before and after 5 minutes of isometric contraction.
RESULTS: The LET disclosed a postexercise decrease in CMAP amplitude in 23 of 25 McArdle patients. The immediate and long-lasting decrease differentiated McArdle patients from controls. Patients with a normal LET demonstrated milder symptoms and/or residual myophosphorylase activity.
CONCLUSIONS: The LET is a sensitive, safe, and noninvasive provocative test that may guide clinicians toward molecular analysis of the myophosphorylase gene. The abnormalities observed on LET point toward complex biochemical mechanisms determined by the absence of myophosphorylase, beyond simple glycolytic blockade (ionic pump dysfunction, sarcolemmal inexcitability). The normal LET in patients with milder symptoms indicates a relationship of the LET with clinical severity, thus identifying it as a potential outcome measure. Muscle Nerve, 2018.
摘要：
背景：在这项研究中，我们评估了电诊断激发测试（长时间运动测试）在McArdle病中的作用。
方法：25名McArdle患者和2名对照组接受了长时间运动测试（LET）的电诊断方案，包括在等距收缩之前和之后5分钟记录复合肌肉动作电位(CMAP)。
结果：LET揭示了25例McArdle患者中有23例运动后CMAP振幅降低。立即和持久的减少将McArdle患者与对照组区分开。LET正常的患者表现出轻度症状和/或残留的肌磷酸化酶活性。
结论：LET是一种敏感的，安全,和非侵入性挑衅性测试，可以指导临床医生对肌磷酸化酶基因的分子分析。在LET上观察到的异常指向由缺乏肌磷酸化酶决定的复杂生化机制，除了简单的糖酵解阻滞(离子泵功能障碍，肌膜不可激发)。症状较轻的患者的正常LET表明LET与临床严重程度的关系，从而将其确定为潜在的结果度量。肌肉神经，2018.
方法：25名McArdle患者和2名对照组接受了长时间运动测试（LET）的电诊断方案，包括在等距收缩之前和之后5分钟记录复合肌肉动作电位(CMAP)。
结果：LET揭示了25例McArdle患者中有23例运动后CMAP振幅降低。立即和持久的减少将McArdle患者与对照组区分开。LET正常的患者表现出轻度症状和/或残留的肌磷酸化酶活性。
结论：LET是一种敏感的，安全,和非侵入性挑衅性测试，可以指导临床医生对肌磷酸化酶基因的分子分析。在LET上观察到的异常指向由缺乏肌磷酸化酶决定的复杂生化机制，除了简单的糖酵解阻滞(离子泵功能障碍，肌膜不可激发)。症状较轻的患者的正常LET表明LET与临床严重程度的关系，从而将其确定为潜在的结果度量。肌肉神经，2018.
