Sonoo M, Tsaiweichao-Shozawa Y, Oshimi-Sekiguchi M, Hatanaka Y, Shimizu T
Department of Neurology, Teikyo University School of Medicine, Itabashi-ku, Tokyo 173-8605, Japan.
Clin Neurophysiol. 2006 Mar;117(3):604-9. doi: 10.1016/j.clinph.2005.11.004. Epub 2006 Jan 3.
To investigate the occurrence of the spread of the radial sensory nerve action potential (SNAP) among patients with carpal tunnel syndrome (CTS) during standard median orthodromic sensory conduction study (SCS) using index finger stimulation.
We prospectively examined 74 hands in 56 CTS patients. We stimulated the index finger using ring electrodes. SNAPs were recorded at wrist over median and radial nerves.
A spread of radial SNAP was clearly identified over the median nerve despite its small amplitude, in 72/74 hands during stimulation of the base of the index finger. In hands with delayed median SNAP, two peaks were observed; however in hands with absence of genuine median SNAP, only one peak of the spread was noticed. The proximal interphalangeal joint (PIP) stimulation still elicited an identifiable spread in 47/74 hands.
This spread phenomenon is a previously undescribed pitfall during the standard median orthodromic SCS, frequently occurring in CTS patients.
In severe CTS cases, one may make wrong conclusion of normal median sensory latency if unaware of this pitfall.
研究在使用食指刺激进行标准正中神经顺向感觉传导研究（SCS）时，腕管综合征（CTS）患者中桡神经感觉神经动作电位（SNAP）的扩散情况。
我们对56例CTS患者的74只手进行了前瞻性检查。我们使用环形电极刺激食指。在腕部的正中神经和桡神经处记录SNAP。
在刺激食指根部时，74只手中有72只手尽管桡神经SNAP幅度较小，但在正中神经上仍清楚地识别出了桡神经SNAP的扩散。在正中神经SNAP延迟的手中，观察到两个峰值；然而，在没有真正正中神经SNAP的手中，仅注意到扩散的一个峰值。近端指间关节（PIP）刺激在74只手中的47只手仍能引起可识别的扩散。
这种扩散现象是标准正中神经顺向SCS过程中一种先前未描述的陷阱，在CTS患者中经常出现。
在严重的CTS病例中，如果未意识到这种陷阱，可能会对正中神经感觉潜伏期正常做出错误结论。
