Section of Neurology, Taichung Veterans General Hospital, Taichung, China.
J Clin Neurophysiol. 2009 Oct;26(5):366-71. doi: 10.1097/WNP.0b013e3181baaafe.
Transcarpal conduction techniques are commonly used to be supplementary techniques to distal sensory and motor latencies (DSL and DML) in the electrodiagnosis of carpal tunnel syndrome (CTS). However, which transcarpal conduction techniques, or combination of techniques, are the most sensitive for the electrodiagnosis of CTS is unknown. To determine which transcarpal conduction technique is the most sensitive for the electrodiagnosis of CTS, we prospectively conduct this study. Study subjects were 100 patients with CTS and 50 controls. In addition to DSL and DML determinations, all subjects were evaluated using four transcarpal conduction techniques. These were (1) median wrist-palm sensory conduction time (W-Psen CT); (2) median wrist-palm mixed nerve conduction time (W-Pmix CT); (3) the difference of conduction time across wrist between median and ulnar nerves (W-Pmix M-U CT); and (4) median wrist-palm motor conduction velocity (W-Pmot CV). The sensitivities and specificities of these tests were compared. Ninety patients had one or more electrophysiologic abnormalities. The DSL and DML diagnostic sensitivities were 74% and 72%, respectively. Better sensitivities were obtained with W-Psen CT (82%), W-Pmot CV (81%), W-Pmix CT (78%), and W-Pmix M-U CT (79%). Compared between four transcarpal conduction techniques, there was no significant difference in sensitivity. Of 26 patients with CTS with normal DSL, additional electrophysiologic abnormalities were revealed with W-Psen CT (30.7%), W-Pmot CV (53.8%), W-Pmix CT (30.7%), or W-Pmix M-U CT (38.5%). When W-Pmot CV was compared with W-Psen CT and W-Pmot CV versus W-Pmix CT, calculated probabilities (P = 0.07) showed a clear trend toward statistical significance. Furthermore, of 20 patients with normal DSL and DML, five patients had abnormality for W-Psen CT, eight for W-Pmot CV, four for W-Pmix CT, and six for W-Pmix M-U CT. On the basis of the results, we concluded that the most simple and reliable transcarpal conduction for electrodiagnosis of CTS was W-Psen CT. The most sensitive technique was W-Pmot CV in subjects with normal DSL or with normal DSL and DML. Evaluation of transcarpal motor conduction affords a useful supplementary technique to W-Psen CT.
腕管正中神经感觉传导潜伏期（W-Psen CT）、正中神经腕部-手掌混合神经传导潜伏期（W-Pmix CT）、正中神经与尺神经腕部传导潜伏期差值（W-Pmix M-U CT）、正中神经腕部-手掌运动传导速度（W-Pmot CV）这 4 种腕管正中神经传导技术，在对腕管综合征（CTS）进行电诊断时，哪一种或哪几种技术最敏感尚不明确。为了确定哪一种腕管正中神经传导技术对 CTS 的电诊断最敏感，我们进行了这项前瞻性研究。研究对象为 100 例 CTS 患者和 50 例对照组。除了测定 DSL 和 DML 之外，所有受试者均接受了 4 种腕管正中神经传导技术评估。这 4 种技术分别为：（1）正中神经腕部-手掌感觉传导潜伏期（W-Psen CT）；（2）正中神经腕部-手掌混合神经传导潜伏期（W-Pmix CT）；（3）正中神经与尺神经腕部传导潜伏期差值（W-Pmix M-U CT）；（4）正中神经腕部-手掌运动传导速度（W-Pmot CV）。比较了这些测试的敏感性和特异性。90 例患者存在 1 种或多种电生理异常。DSL 和 DML 的诊断敏感性分别为 74%和 72%。W-Psen CT（82%）、W-Pmot CV（81%）、W-Pmix CT（78%）和 W-Pmix M-U CT（79%）的敏感性更好。与 4 种腕管正中神经传导技术相比，W-Psen CT 的敏感性无显著差异。26 例 CTS 患者 DSL 正常，通过 W-Psen CT（30.7%）、W-Pmot CV（53.8%）、W-Pmix CT（30.7%）或 W-Pmix M-U CT（38.5%）发现了其他电生理异常。当比较 W-Pmot CV 与 W-Psen CT 及 W-Pmot CV 与 W-Pmix CT 时，计算概率（P = 0.07）显示出统计学意义的明显趋势。此外，在 20 例 DSL 和 DML 正常的患者中，5 例患者 W-Psen CT 异常，8 例患者 W-Pmot CV 异常，4 例患者 W-Pmix CT 异常，6 例患者 W-Pmix M-U CT 异常。基于这些结果，我们得出结论，对 CTS 电诊断而言，最简单、最可靠的腕管正中神经传导技术是 W-Psen CT。在 DSL 正常或 DSL 和 DML 正常的患者中，最敏感的技术是 W-Pmot CV。正中神经腕部运动传导评估是 W-Psen CT 的有用补充技术。
