■慢性疼痛与触觉敏锐度差有关,通常用两点判别(TPD)测试测量。尽管在慢性疼痛情况下触觉敏锐度差已得到证实,在急性疼痛中已知较少。
■最近在实验诱发的颈部和背部疼痛中相互矛盾的发现使我们对实验诱发的肢体疼痛进行了TPD研究。我们假设在实验性上肢疼痛期间改变了TPD,但是我们没有推测变化的方向。
■30名健康受试者将其优势手浸入7°C的循环冷水浴中(冷加压试验[CPT])。在基线(CPT前)测量两点判别,疼痛期间(CPT期间),在3个不同的地点从水中撤出(CPT后):(1)优势前臂,(2)优势臂和(3)对侧前臂。
■重复测量方差分析显示时间对TPD的显着主要影响(F(2,56)=4.45,P=0.02,ηp2=0.14);在所有3个站点中,TPD值下降(即,触觉敏锐度改善)疼痛期间。有趣的是,对侧前臂遵循与显性相似的模式(即,疼痛)前臂,而且是唯一与疼痛相关的部位,尽管在一个有趣的方向(r=0.57,P=0.001),ie,疼痛越大,触觉敏锐度越差。
■在实验诱发的肢体疼痛期间触觉敏锐度的改善可能反映了保护性反应。对侧肢体中相应部位的变化可能反映出保护性脊柱串扰。这样的回应,以及触觉敏锐度和疼痛之间有趣的关系,需要进一步调查。
UNASSIGNED: Chronic pain is associated with poor tactile acuity, commonly measured with the 2-point discrimination (
TPD) test. Although poor tactile acuity across chronic pain conditions is well established, less is known in acute pain.
UNASSIGNED: Recent conflicting findings in experimentally induced neck and back pain led us to conduct a
TPD investigation in experimentally induced limb pain. We hypothesised altered
TPD during experimental upper limb pain, but we did not speculate on the direction of the change.
UNASSIGNED: Thirty healthy subjects immersed their dominant hand in a circulating cold-water bath at 7°C (cold pressor test [CPT]). Two-point discrimination was measured at baseline (pre-CPT), during pain (during-CPT), and after withdrawal from the water (post-CPT) in 3 different sites: (1) the dominant forearm, (2) dominant arm and (3) contralateral forearm.
UNASSIGNED: Repeated-measures analysis of variance revealed a significant main effect of time (F(2,56) = 4.45, P = 0.02, ηp2 = 0.14) on
TPD; in all 3 sites,
TPD values decreased (ie, tactile acuity improved) during pain. Interestingly, the contralateral forearm followed a similar pattern to the dominant (ie, painful) forearm, and furthermore was the only site that exhibited any correlation with pain, albeit in an intriguing direction (r = 0.57, P = 0.001), ie, the greater the pain the worse the tactile acuity.
UNASSIGNED: The improvements in tactile acuity during experimentally induced limb pain may reflect a protective response. The changes in the corresponding site in the contralateral limb may reflect a protective spinal cross talk. Such a response, together with the interesting relationship between tactile acuity and pain, warrant further inquiry.