Electromyography Laboratory, Department of Neurology, Veterans Administration Medical Center, University of Tennessee, Memphis, TN, United States.
Handb Clin Neurol. 2023;195:251-270. doi: 10.1016/B978-0-323-98818-6.00019-4.
The electrodiagnostic (EDX) study is an extension of the clinical examination, which means that the clinical features dictate the initial nerve conduction studies (NCS) performed. However, once the EDX study is started, it continues in an independent manner, meaning that the initial NCS findings dictate the subsequent studies performed. Because competent EDX study performance requires considerable knowledge (and special training), it is not possible to convey all of the basic and advanced concepts in a single chapter. Nonetheless, the most important concepts are easily conveyed by a discussion limited to EDX-pertinent anatomical, physiological, pathological, pathophysiological, and basic electrical concepts. The focus of this chapter will be on the standard NCS and needle EMG measurements made during EDX studies and their significance with regard to lesion localization and characterization. Because the most challenging portion of EDX study is motor unit action potential analysis, this topic is more extensively reviewed. The utility of the sensory NCS for identifying focal axon loss, the utility of the motor NCS for screening long nerve segments for focal demyelination and for determining lesion severity, and the utility of the needle EMG for confirming the NCS findings, better defining lesion localization, and identifying the temporal features (e.g., chronicity) and rate of progression of the lesion are also reviewed.
电诊断 (EDX) 研究是临床检查的延伸，这意味着临床特征决定了最初进行的神经传导研究 (NCS)。然而，一旦开始进行 EDX 研究，它就会以独立的方式继续进行，这意味着最初的 NCS 发现决定了随后进行的研究。由于进行合格的 EDX 研究需要相当多的知识（和特殊培训），因此不可能在一章中传达所有基本和高级概念。尽管如此，通过仅限于 EDX 相关的解剖学、生理学、病理学、病理生理学和基本电概念的讨论，仍然可以很容易地传达最重要的概念。本章的重点将是 EDX 研究期间进行的标准 NCS 和针极肌电图测量及其与病变定位和特征描述的关系。由于 EDX 研究中最具挑战性的部分是运动单位动作电位分析，因此这个主题将进行更广泛的回顾。感觉 NCS 用于识别局灶性轴索损失的效用、运动 NCS 用于筛选长神经节段的局灶性脱髓鞘和确定病变严重程度的效用，以及针极肌电图用于确认 NCS 发现、更好地定义病变定位和识别病变的时间特征（例如，慢性）和进展速度的效用也将进行回顾。
