Department of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo 1738605, Japan.
Muscle Nerve. 2011 May;43(5):671-8. doi: 10.1002/mus.21931.
The compound muscle action potential (CMAP) following ulnar nerve stimulation receives a considerable contribution from far-field potentials (FFPs), although their origin is not entirely clear. We investigated this issue using voluntary contractions.
In 7 control subjects, we placed multiple recording electrodes over the motor points of ulnar-innervated muscles. We asked the subjects to perform a weak movement corresponding to the action of each muscle, and identified the single motor unit potentials (MUPs) from that muscle. We summed the MUPs from each individual muscle and reconstructed the CMAPs.
The reconstructed CMAPs coincided well with the actual ones. The N1, P1, and early N2 components of the FFPs were generated primarily by palmar, but also by dorsal, interosseous muscles. The abductor digiti minimi muscle usually generated positive-negative biphasic FFPs, and the negative FFP generated the late N2 component.
These results should prompt a revision of the theory of FFP generation.
尺神经刺激后的复合肌肉动作电位（CMAP）会受到远场电位（FFP）的很大影响，尽管其起源尚不完全清楚。我们使用随意收缩对此问题进行了研究。
在 7 名对照受试者中，我们在尺神经支配肌肉的运动点上放置了多个记录电极。我们要求受试者进行与每个肌肉相应的微弱运动，并识别出来自该肌肉的单个运动单位电位（MUP）。我们对每个单独肌肉的 MUP 进行了求和，并重建了 CMAP。
重建的 CMAP 与实际的 CMAP 吻合得很好。FFP 的 N1、P1 和早期 N2 成分主要由掌侧肌产生，但也由背侧和骨间肌产生。小指展肌通常产生正负双相的 FFP，而负 FFP 产生晚期 N2 成分。
这些结果应该促使对 FFP 产生理论进行修正。
