Luo Y M, Polkey M I, Johnson L C, Lyall R A, Harris M L, Green M, Moxham J
King's College, London SE5 9PJ, United Kingdom.
J Appl Physiol (1985). 1998 Dec;85(6):2089-99. doi: 10.1152/jappl.1998.85.6.2089.
The purpose of the study was to compare electrical stimulation (ES) and cervical magnetic stimulation (CMS) of the phrenic nerves for the measurement of the diaphragm compound muscle action potential (CMAP) and phrenic nerve conduction time. A specially designed esophageal catheter with three pairs of electrodes was used, with control of electrode positioning in 10 normal subjects. Pair A and pair B were close to the diaphragm (pair A lower than pair B); pair C was positioned 10 cm above the diaphragm to detect the electromyogram from extradiaphragmatic muscles. Electromyograms were also recorded from upper and lower chest wall surface electrodes. The shape of the CMAP measured with CMS (CMS-CMAP) usually differed from that of the CMAP measured with ES (ES-CMAP). Moreover, the latency of the CMS-CMAP from pair B (5.3 +/- 0.4 ms) was significantly shorter than that from pair A (7.1 +/- 0.7 ms). The amplitude of the CMS-CMAP (1.00 +/- 0.15 mV) was much higher than that of ES-CMAP (0.26 +/- 0.15 mV) when recorded from pair C. Good-quality CMS-CMAPs could be recorded in some subjects from an electrode positioned very low in the esophagus. The differences between ES-CMAP and CMS-CMAP recorded either from esophageal or chest wall electrodes make CMS unreliable for the measurement of phrenic nerve conduction time.
本研究的目的是比较膈神经的电刺激（ES）和颈磁刺激（CMS）在测量膈肌复合肌肉动作电位（CMAP）和膈神经传导时间方面的效果。使用了一种专门设计的带有三对电极的食管导管，并在10名正常受试者中控制电极定位。A组和B组电极靠近膈肌（A组低于B组）；C组电极位于膈肌上方10 cm处，用于检测膈肌外肌肉的肌电图。还从胸壁上下表面电极记录肌电图。用CMS测量的CMAP（CMS-CMAP）的形状通常与用ES测量的CMAP（ES-CMAP）不同。此外，B组CMS-CMAP的潜伏期（5.3±0.4 ms）明显短于A组（7.1±0.7 ms）。从C组记录时，CMS-CMAP的波幅（1.00±0.15 mV）远高于ES-CMAP（0.26±0.15 mV）。在一些受试者中，从食管中位置很低的电极可以记录到高质量的CMS-CMAP。从食管或胸壁电极记录的ES-CMAP和CMS-CMAP之间的差异使得CMS在测量膈神经传导时间方面不可靠。
