Xu Ying-sheng, Zheng Ju-yang, Zhang Shuo, Zhang Jun, Kang De-xuan, Fan Dong-sheng
Department of Neurology, Beijing University Third Hospital, Beijing 100083, China.
Zhonghua Yi Xue Za Zhi. 2007 Jan 30;87(5):321-4.
To establish a method to evoke cerebral potentials by stimulating nociceptive fibers, estimate the conduction velocities of nerve fibers mediating these responses, and assess the value of the potentials in carpal tunnel syndrome.
One hundred patients with carpal tunnel syndrome and 20 sex-, and aged-matched healthy persons underwent stimulation of contact heat delivered via a circular thermode to excite selectively nociceptors with a rapid rising time at 70 degrees C/s to elicit pain and contact heat evoked potential (CHEP). Thermal stimuli were sent at two intensity levels (49.5 degrees C and 54.5 degrees C) to three body sites: thenar eminence, dorsum of hand, and proximal volar forearm The CHEPs were recorded from Cz and Pz. The relation between the stimulus intensity and pain rating was observed, and the main components of the evoked potential were recorded. The nerve conduction velocity was calculated from the latency difference of the CHEP and center to center distance of distal and proximal stimulus arrays.
The pain intensity ratings were 3.2 +/- 0.3 and 4.4 +/- 0.5 when the thenar eminence was stimulated at the temperature of 49.5 degrees C and 54.5 degrees C respectively; and the ratings were 6.3 +/- 0.8 and 7.2 +/- 0.5 on the dorsum of hand and proximal volar forearm at the temperature of 54.5 degrees C respectively. Three components, Cz/N550, Cz/P750, and Pz/P1000, were found in the evoked potentials. The latency of the CHEP was significantly correlated with the arm length, and not significantly correlated with sex, age, and side difference of the arm. The conduction velocities of the Adelta and C fibers of the carpal tunnel syndrome patients were 12.0 m/s +/- 5.6 m/s and 0.6 m/s +/- 0.1 m/s respectively, both lowered, being 93.8% and 99.5% of those of the healthy persons (12.9 m/s +/- 7.5 m/s and 1.7 m/s +/- 0.4m/s respectively).
Elicited reliably, CHEP is mediated by Adelta and C fibers. The conduction velocity of C fibers in the patients with carpal tunnel syndrome is decreased.
建立一种通过刺激伤害性纤维诱发脑电位的方法，估计介导这些反应的神经纤维的传导速度，并评估这些电位在腕管综合征中的价值。
100例腕管综合征患者和20例年龄、性别匹配的健康人接受通过圆形热电极传递的接触热刺激，以70℃/s的快速上升时间选择性地激发伤害感受器，引发疼痛和接触热诱发电位（CHEP）。热刺激以两种强度水平（49.5℃和54.5℃）发送到三个身体部位：鱼际、手背和掌侧前臂近端。CHEP从Cz和Pz记录。观察刺激强度与疼痛评分之间的关系，并记录诱发电位的主要成分。根据CHEP的潜伏期差异和远端与近端刺激阵列的中心距计算神经传导速度。
当鱼际在49.5℃和54.5℃温度下受到刺激时，疼痛强度评分分别为3.2±0.3和4.4±0.5；在54.5℃温度下，手背和掌侧前臂近端的评分分别为6.3±0.8和7.2±0.5。在诱发电位中发现了三个成分，即Cz/N550、Cz/P750和Pz/P1000。CHEP的潜伏期与手臂长度显著相关，与性别、年龄和手臂的左右差异无显著相关性。腕管综合征患者的Aδ纤维和C纤维传导速度分别为12.0m/s±5.6m/s和0.6m/s±0.1m/s，均降低，分别为健康人（分别为12.9m/s±7.5m/s和1.7m/s±0.4m/s）的93.8%和99.5%。
CHEP诱发可靠，由Aδ纤维和C纤维介导。腕管综合征患者C纤维的传导速度降低。
