Differential Effects of Thermal Stimuli in Eliciting Temporal Contrast Enhancement: A Psychophysical Study

Luisa Luebke; Janne von Selle; Wacław M Adamczyk; Moritz J Knorr; Gabriela F Carvalho; Philip Gouverneur; Kerstin Luedtke; Tibor M Szikszay

doi:10.1016/j.jpain.2023.08.005

Differential Effects of Thermal Stimuli in Eliciting Temporal Contrast Enhancement: A Psychophysical Study

J Pain. 2024 Jan;25(1):228-237. doi: 10.1016/j.jpain.2023.08.005. Epub 2023 Aug 15.

Authors

Luisa Luebke¹, Janne von Selle², Wacław M Adamczyk³, Moritz J Knorr², Gabriela F Carvalho⁴, Philip Gouverneur⁵, Kerstin Luedtke¹, Tibor M Szikszay¹

Affiliations

¹ Institute of Health Sciences, Department of Physiotherapy, Pain and Exercise Research Luebeck (P.E.R.L.), University of Luebeck, Lübeck, Schleswig-Holstein, Germany; Center of Brain, Behavior and Metabolism (CBBM), University of Luebeck, Lübeck, Schleswig-Holstein, Germany.
² Institute of Health Sciences, Department of Physiotherapy, Pain and Exercise Research Luebeck (P.E.R.L.), University of Luebeck, Lübeck, Schleswig-Holstein, Germany.
³ Laboratory of Pain Research, Institute of Physiotherapy and Health Sciences, The Jerzy Kukuczka Academy of Physical Education, Katowice, Schlesien, Poland; Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.
⁴ Department of Physiotherapy, Faculty of Health, Safety and Society, Furtwangen University, Furtwangen, Germany.
⁵ Institute of Medical Informatics, University of Luebeck, Lübeck, Schleswig-Holstein, Germany.

PMID: 37591481
DOI: 10.1016/j.jpain.2023.08.005

Abstract

Offset analgesia (OA) is observed when pain relief is disproportional to the reduction of noxious input and is based on temporal contrast enhancement (TCE). This phenomenon is believed to reflect the function of the inhibitory pain modulatory system. However, the mechanisms contributing to this phenomenon remain poorly understood, with previous research focusing primarily on painful stimuli and not generalizing to nonpainful stimuli. Therefore, the aim of this study was to investigate whether TCE can be induced by noxious as well as innocuous heat and cold stimuli. Asymptomatic subjects (n = 50) were recruited to participate in 2 consecutive experiments. In the first pilot study (n = 17), the parameters of noxious and innocuous heat and cold stimuli were investigated in order to implement them in the main study. In the second (main) experiment, subjects (n = 33) participated in TCE paradigms consisting of 4 different modalities, including noxious heat (NH), innocuous heat (IH), noxious cold (NC), and innocuous cold (IC). The intensity of the sensations of each thermal modality was assessed using an electronic visual analog scale. TCE was confirmed for NH (P < .001), NC (P = .034), and IC (P = .002). Conversely, TCE could not be shown for IH (P = 1.00). No significant correlation between TCE modalities was found (r < .3, P > .05). The results suggest that TCE can be induced by both painful and nonpainful thermal stimulation but not by innocuous warm temperature. The exact underlying mechanisms need to be clarified. However, among other potential mechanisms, this may be explained by a thermo-specific activation of C-fiber afferents by IH and of A-fiber afferents by IC, suggesting the involvement of A-fibers rather than C-fibers in TCE. More research is needed to confirm a peripheral influence. PERSPECTIVE: This psychophysical study presents the observation of temporal contrast enhancement during NH, NC, and innocuous cold stimuli but not during stimulation with innocuous warm temperatures in healthy volunteers. A better understanding of endogenous pain modulation mechanisms might be helpful in explaining the underlying aspects of pain disorders.

Keywords: Offset analgesia; endogenous pain inhibition; healthy; pain; thermal stimulation.

MeSH terms

Cold Temperature*
Hot Temperature
Humans
Pain*
Pilot Projects
Temperature