Pharmacological dissection of the paradoxical pain induced by a thermal grill. - Archive ouverte HAL Access content directly
Journal Articles PAIN Year : 2008

Pharmacological dissection of the paradoxical pain induced by a thermal grill.

(1) , (1) , (1) , (1)
1

Abstract

We investigated the role of the glutamatergic and endogenous opioidergic systems in the paradoxical pain evoked by the simultaneous application of innocuous warm and cold stimuli to the skin with a "thermal grill". Two parallel randomized, double-blind, cross-over studies, including two groups of 12 healthy volunteers, were carried out to compare the effects of i.v. ketamine or naloxone to those of placebo, on the sensations produced by a thermode (i.e. thermal grill) composed of six bars applied on the palmar surface of the right hand. The temperature of alternate (even- and odd-numbered) bars could be controlled independently by Peltier elements to produce various patterns of the grill. During each experimental session we measured the effects of ketamine, naloxone or placebo on the intensity of: (i) paradoxical pain; (ii) "normal" thermal (heat and cold) pain; and (iii) non-painful thermal (warm and cool) sensations. Ketamine administration resulted in a significant reduction of paradoxical pain intensity but did not alter normal pain or non-painful thermal sensations. By contrast, naloxone had no effect on paradoxical pain, normal pain or non-painful thermal sensations. This study demonstrates for the first time that the "thermal grill illusion of pain" can be modulated pharmacologically. This paradoxical pain, which involves the glutamatergic systems, acting through the NMDA receptors, but not the tonic endogenous opioids systems, might share some mechanisms with pathological pain.
Fichier principal
Vignette du fichier
Thermal_pharmakern_HAL.pdf (110.15 Ko) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

inserm-00313770 , version 1 (27-08-2008)

Identifiers

Cite

Delphine Kern, Emilie Pelle-Lancien, Virginie Luce, Didier Bouhassira. Pharmacological dissection of the paradoxical pain induced by a thermal grill.. PAIN, 2008, 135 (3), pp.291-9. ⟨10.1016/j.pain.2007.12.001⟩. ⟨inserm-00313770⟩

Collections

INSERM UVSQ
249 View
544 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More