Wasner Gunnar L, Brock James A
Department of Neurology, Division of Neurological Pain Research and Therapy, University Clinic of Schleswig-Holstein, Campus Kiel, Schittenhelmstrasse 10, 24105 Kiel, Germany.
Clin Neurophysiol. 2008 Oct;119(10):2389-95. doi: 10.1016/j.clinph.2008.07.223. Epub 2008 Sep 7.
Measurement of thermal pain thresholds is an essential part of quantitative sensory testing (QST). However, databases of QST show limitations due to large inter-individual variations including unreasonably low thresholds for thermal pain, lack of data on intra-individual variations over time and on the subjects' perception at threshold. This study sought to reduce inter-individual variations, investigated the reproducibility of measurements of thermal pain thresholds and included evaluation of thermally induced perceptions.
Thermal pain thresholds were investigated in 20 healthy subjects over three weeks using two protocols, one of which differed in making the subjects familiar with the likely range of applied temperatures beforehand. Both protocols included subjective ratings of pain and temperature perception at the pain thresholds.
Data obtain using both protocols showed large inter-individual variations, but small intra-individual variations of pain thresholds over time as well as good feasibility and reproducibility of subjects' ratings at threshold.
Previous experience of test stimuli has no influence on the variability of thermal pain thresholds. However, measurement of thermal pain thresholds showed good reproducibility over time. Evaluation of perception at thresholds provided further reproducible data.
Further approaches are needed to reduce variability of thermal pain thresholds; however, good reproducibility of thermal pain thresholds and thermally induced perceptions warrants consideration of their use in larger longitudinal studies.
热痛阈值的测量是定量感觉测试（QST）的重要组成部分。然而，QST数据库存在局限性，因为个体间差异很大，包括热痛阈值低得不合理、缺乏个体随时间的变化数据以及受试者在阈值时的感知数据。本研究旨在减少个体间差异，研究热痛阈值测量的可重复性，并包括对热诱导感知的评估。
使用两种方案对20名健康受试者进行了为期三周的热痛阈值研究，其中一种方案的不同之处在于事先让受试者熟悉可能的应用温度范围。两种方案都包括对疼痛阈值时的疼痛和温度感知进行主观评分。
使用两种方案获得的数据显示个体间差异很大，但疼痛阈值随时间的个体内差异很小，并且受试者在阈值时的评分具有良好的可行性和可重复性。
测试刺激的既往经验对热痛阈值的变异性没有影响。然而，热痛阈值的测量随时间显示出良好的可重复性。对阈值时感知的评估提供了进一步的可重复数据。
需要进一步的方法来降低热痛阈值的变异性；然而，热痛阈值和热诱导感知的良好可重复性值得考虑在更大规模的纵向研究中使用它们。
