Department of Neurology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Clin Neurophysiol. 2010 May;121(5):712-3. doi: 10.1016/j.clinph.2009.12.019. Epub 2010 Jan 13.
Position of recording electrodes for the antidromic sensory-nerve conduction study (SCS) of the medial antebrachial cutaneous (MABC) nerve is conventionally determined according to the anatomical landmarks. However, the variation of its nerve course may interfere with accurate placement. In this study, we aimed to test how the systematic two-step examination, an orthodromic-antidromic series, affects the results.
Subjects were 40 arms from 20 control subjects. For the two-step method, we first searched for the minimal threshold point over the forearm using the orthodromic technique. The recording electrode for the antidromic SCS was placed over the optimal point determined in this way.
The SNAP amplitude by our two-step method was 1.39 times (range 0.99-3.94) of that by the conventional method. Four out of 20 subjects showed greater than 50% (up to 83%) interside difference of the SNAP amplitude by the conventional methods, whereas the maximal interside difference was 38% by the two-step method.
Careful adjustment of the recording position using the two-step method would contribute to an accurate evaluation of the MABC nerve.
To determine the recording position solely based on anatomical landmarks may cause erroneously abnormal interside difference for this nerve.
顺行感觉神经传导研究（SCS）中记录正中前臂皮神经（MABC）电极的位置通常根据解剖学标志来确定。然而，其神经路径的变化可能会干扰准确的定位。在这项研究中，我们旨在测试系统的两步检查，即顺行-逆行系列，如何影响结果。
受试者为 20 名对照受试者的 40 只手臂。对于两步法，我们首先使用顺行技术在前臂上寻找最小阈值点。将记录电极置于以这种方式确定的最佳点上进行逆行 SCS。
我们的两步法的 SNAP 幅度是传统方法的 1.39 倍（范围 0.99-3.94）。在 20 名受试者中，有 4 名受试者的 SNAP 幅度的传统方法两侧差异大于 50%（高达 83%），而两步法的最大两侧差异为 38%。
使用两步法仔细调整记录位置将有助于对 MABC 神经进行准确评估。
仅根据解剖学标志来确定记录位置可能会导致该神经的错误异常两侧差异。
