Spatial discrimination thresholds for pain and touch in human hairy skin
Spatial discrimination thresholds for pain and touch in human hairy skin
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DOI：
10.1016/s0304-3959(00)00484-x
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发表时间：
2001-05-01
期刊：
影响因子：
7.4
通讯作者：
Treede, RD
中科院分区：
文献类型：
--
作者：
Schlereth, T;Magerl, W;Treede, RD
传统的疼痛定位不良的概念受到了最近研究的挑战，在这些研究中，受试者能够以10-20 mm的精度指向皮肤上的刺激点。然而，指向运动本身具有约15 mm的误差。为了确定独立于运动表现的伤害感受系统的感觉表现的极限，在12名健康受试者中，以两种选择的强制选择范例测试了热痛（540 mJ点状激光刺激，5 mm直径）、机械痛（256 mN点状探针，200 μ m直径）和触摸（16 mN vonFrey探针，1.1 mm直径）的点定位。以随机顺序将刺激施加到手背上的两条平行线（4-32 mm距离）。正确定位的累积分布函数对于所有测试刺激都具有类似的S形。表示对数正态分布。疼痛性发热的75%正确定位阈值为8.6 mm（3.1 +/- 0.1 log（2）单位），与非疼痛性触摸的阈值（9.0 mm，3.2 +/- 0.2 log（2）单位）无显著差异。机械引起的疼痛（5.1 mm，2.4 +/- 0.2 log（2）单位）的定位比热痛和触摸明显更准确，这可能是由于同时激活的两种不同感觉通道（触觉通道和伤害性通道）的协同作用。对于所有三种刺激，辨别力在桡尺方向上明显优于近远方向，这可能与椭圆形的接受保持形状有关。触摸的顺序空间辨别力明显优于用光栅定向任务测试的同时空间辨别力（18.9 mm），但两者都比指尖差一个数量级（1.3 mm，0.4 +/- 0.1 log（2）单位）。总之。由辐射热脉冲引起的疼痛和由vonFrey探针引起的触摸在手背上以相似的精度定位。这些发现表明，在指尖或嘴唇的触觉中心凹外，伤害性和触觉系统的空间辨别能力大致相等。(C)2001年国际疼痛研究协会。由Elsevier Science B. V.出版，版权所有。
The traditional concept that pain is poorly localized has been challenged by recent studies, where subjects were able to point to the stimulated spot on the skin with an accuracy of 10-20 mm. Pointing movements themselves, however, have errors of about 15 mm. To determine the limits of sensory performance of the nociceptive system independent of motor performance, point localization of heat pain (540 mJ punctate laser stimuli, 5 mm diameter), mechanical pain (256 mN punctate probe, 200 mum diameter), and touch (16 mN von Frey probe, 1.1 mm diameter) were tested in a two-alternative forced-choice paradigm in 12 healthy subjects. Stimuli were applied in randomized order to two parallel lines on the back of the hand (4-32 mm distance). The cumulative distribution functions for correct localization were of similar sigmoid shape for all test stimuli. indicating logarithmic normal distributions. The 75% correct localization threshold for painful heat was 8.6 mm (3.1 +/- 0.1 log(2) units) and did not differ significantly from that of non-painful touch (9.0 mm, 3.2 +/- 0.2 log(2) units). Localization of mechanically-induced pain (5.1 mm. 2.4 +/- 0.2 log(2) units) was significantly more accurate than both heat pain and touch, possibly due to a synergism of two different sensory channels, the tactile channel and the nociceptive channel, which were activated simultaneously. For all three stimuli, discrimination was significantly better in radial-ulnar compared to proximal-distal direction, which might be related to oval receptive held shapes. Sequential spatial discrimination for touch was significantly better than simultaneous spatial discrimination tested with a grating orientation task (18.9 mm), but both were one order of magnitude worse than at the finger tip ( 1.3 mm, 0.4 +/- 0.1 log(2) units). In conclusion. pain evoked by radiant heat pulses and touch evoked by von Frey probes were localized with similar precision on the back of the hand. These findings indicate that outside the tactile fovea at finger tips or lips the spatial discrimination capacities of the nociceptive and tactile systems are about equal. (C) 2001 International Association for the Study of Pain. Published by Elsevier Science B.V. All rights reserved.