Chen I-An, Hung Steven Wu, Chen Yu-Hsien, Lim Siew-Na, Tsai Yu-Tai, Hsiao Cheng-Lun, Hsieh Hsiang-Yao, Wu Tony
Epilepsy Section, Department of Neurology, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taipei, Taiwan.
Acta Neurol Taiwan. 2006 Sep;15(3):184-91.
Laser-evoked potentials are widely used to investigate nociceptive pathways. The newly developed contact heat stimulator for evoking brain response has the advantages of obtaining reliable scalp potentials and absence of cutaneous lesions. This study aimed to identify the most appropriate stimulation site with consistent cortical responses, and to correlate several parameters of the contact heat evoked potentials (CHEPs) with age, gender, and body height in normal subjects. CHEPs were recorded at Cz with a contact heat stimulator (Medoc, Israel) in 35 normal controls. The subjects were asked to keep eyes open and remain alert. The baseline temperature was 32 degrees C, and stimulation peak heat intensity of 51 degrees C was applied to five body sites: bilateral forearm, right dorsum hand, right peroneal area, and right dorsum foot. Reproducible CHEPs were recorded more frequently when stimulated at volar forearm (62.5%) than at the lower limbs (around 40%). The first negative peak latency (N1) was 370.1 +/- 20.3 ms, first positive peak latency (P1) was 502.4 +/- 33.0 ms, and peak to peak amplitude was 10.2 +/- 4.9 microV with stimulation of the forearm. Perceived pain intensity was not correlated with the presence or amplitude of CHEPs. No gender or inter-side differences were observed for N1 latency and N1-P1 amplitude. Also, no correlation was noted between N1 and age or body height. These results support future clinical access of CHEPs as a diagnostic tool.
激光诱发电位被广泛用于研究伤害性感受通路。新开发的用于诱发脑反应的接触热刺激器具有获得可靠头皮电位且无皮肤损伤的优点。本研究旨在确定能产生一致皮层反应的最合适刺激部位，并将接触热诱发电位（CHEPs）的几个参数与正常受试者的年龄、性别和身高进行关联。在35名正常对照者中，使用接触热刺激器（以色列Medoc公司）在头顶中央（Cz）记录CHEPs。受试者被要求睁眼并保持警觉。基线温度为32摄氏度，将51摄氏度的刺激峰值热强度施加于五个身体部位：双侧前臂、右手背、右腓骨区域和右脚背。在前臂掌侧进行刺激时，比在下肢进行刺激时更频繁地记录到可重复的CHEPs（62.5% 比 40%左右）。刺激前臂时，第一个负向峰值潜伏期（N1）为370.1±20.3毫秒，第一个正向峰值潜伏期（P1）为502.4±33.0毫秒，峰峰值幅度为10.2±4.9微伏。感觉到的疼痛强度与CHEPs的出现或幅度无关。未观察到N1潜伏期和N1 - P1幅度存在性别差异或双侧差异。此外，未发现N1与年龄或身高之间存在相关性。这些结果支持CHEPs未来作为一种诊断工具在临床中的应用。
