Institute of Cognitive and Clinical Neuroscience, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany.
Biopsychology and Cognitive Neuroscience, Faculty of Psychology and Sports Science, Bielefeld University, Bielefeld, Germany.
Eur J Pain. 2022 Jan;26(1):114-132. doi: 10.1002/ejp.1842. Epub 2021 Aug 8.
The mechanisms underlying chronic phantom limb pain (PLP) are complex and insufficiently understood. Altered sensory thresholds are often associated with chronic pain but quantitative sensory testing (QST) in PLP has so far been inconclusive due to large methodological variation between studies and small sample sizes.
In this study, we applied QST in 37 unilateral upper-limb amputees (23 with and 14 without PLP) and 19 healthy controls. We assessed heat pain (HPT), pressure pain, warmth detection and two-point discrimination thresholds at the residual limb, a homologous point and the thenar of the intact limb as well as both corners of the mouth.
We did not find significant differences in any of the thresholds between the groups. However, PLP intensity was negatively associated with HPT at all measured body sites except for the residual limb, indicating lower pain thresholds with higher PLP levels. Correlations between HPT and PLP were strongest in the contralateral face (r = -0.65, p < 0.001). Facial HPT were specifically associated with PLP, independent of residual limb pain (RLP) and various other covariates. HPT at the residual limb, however, were significantly associated with RLP, but not with PLP.
We conclude that the association between PLP and, especially facial, HPT could be related to central mechanisms.
Phantom limb pain (PLP) is still poorly understood. We show that PLP intensity is associated with lower heat pain thresholds, especially in the face. This finding could be related to central nervous changes in PLP.
慢性幻肢痛（PLP）的发病机制复杂，目前尚不完全清楚。感觉阈值的改变通常与慢性疼痛有关，但由于研究之间方法学差异较大和样本量较小，PLP 的定量感觉测试（QST）结果尚无定论。
本研究对 37 例单侧上肢截肢者（23 例有 PLP，14 例无 PLP）和 19 例健康对照者进行了 QST。我们评估了残肢、同源点和完整手的大鱼际处以及口腔两侧的热痛（HPT）、压痛、温觉检测和两点辨别觉阈值。
我们未发现组间任何阈值存在显著差异。然而，除残肢外，PLP 强度与所有测量部位的 HPT 呈负相关，表明 PLP 水平越高，疼痛阈值越低。HPT 与 PLP 之间的相关性在对侧面部最强（r=-0.65，p<0.001）。面部 HPT 与 PLP 相关，与残肢痛（RLP）和其他各种混杂因素无关。然而，残肢的 HPT 与 RLP 显著相关，但与 PLP 无关。
我们的结论是，PLP 与尤其是面部 HPT 之间的关联可能与中枢机制有关。
幻肢痛（PLP）仍知之甚少。我们发现 PLP 强度与较低的热痛阈值相关，尤其是在面部。这一发现可能与 PLP 中枢神经变化有关。
