Department of Neurology, University of Münster, Albert-Schweitzer-Straße 33, 48149 Münster, Germany; Department of Neurology, University of München, Marchioninistraße 15, 81377 München, Germany.
Clin Neurophysiol. 2013 Nov;124(11):2242-7. doi: 10.1016/j.clinph.2013.05.003. Epub 2013 Jun 5.
Contact heat evoked potentials (CHEPs) mediated by primary afferent Aδ-fibers can be recorded at the vertex. CHEPs are reduced in small fibre neuropathy and considered as a noninvasive measure of small fibre function. As long-term stability of CHEPs has not been examined, it is presently not clear if CHEPs may also be useful for following the course of small fibre neuropathy.
Here, we analyzed CHEPs from 60 healthy subjects recorded at two occasions separated by 6 months.
There was a systematic shift towards larger amplitudes (from 40.2 ± 13.8 μV to 53.3 ± 17.5 μV, p<0.001) and towards shorter latencies (from 425.0 ± 28.8 ms to 387.2 ± 30.3 ms, p<0.001) after six months, while CHEP areas were more constant over time.
The present results show that systematic changes of CHEP amplitudes and latencies may occur over time. Possible reasons include seasonal differences in skin conductivity for heat and psychological effects.
CHEP areas seem to be more stable over time than amplitudes or latencies, however, it remains to be determined if CHEP areas differentiate between subjects with lesions of the nociceptive system and healthy controls as reliably as CHEP amplitudes.
初级传入 Aδ 纤维介导的接触热诱发电位（CHEPs）可在顶点记录。CHEPs 在小纤维神经病中减少，被认为是小纤维功能的非侵入性测量。由于 CHEPs 的长期稳定性尚未检查，目前尚不清楚 CHEPs 是否也可用于跟踪小纤维神经病的病程。
在这里，我们分析了 60 名健康受试者在两次相隔 6 个月的情况下记录的 CHEPs。
在 6 个月后，有一个系统的变化，即幅度增大（从 40.2 ± 13.8 μV 变为 53.3 ± 17.5 μV，p<0.001）和潜伏期缩短（从 425.0 ± 28.8 ms 变为 387.2 ± 30.3 ms，p<0.001），而 CHEP 面积随时间更稳定。
目前的结果表明，CHEP 的幅度和潜伏期可能会随时间发生系统性变化。可能的原因包括皮肤对热的电导率的季节性差异和心理影响。
CHEP 面积似乎比幅度或潜伏期更稳定，但仍有待确定 CHEP 面积是否像 CHEP 幅度一样可靠地区分疼痛系统损伤的受试者和健康对照者。
