Back to Search
Start Over
Effects of cold stimulation on secondary hyperalgesia (HA) induced by capsaicin in healthy volunteers.
- Source :
- Experimental Brain Research; Mar2006, Vol. 170 Issue 1, p22-29, 8p, 5 Graphs
- Publication Year :
- 2006
-
Abstract
- Little is known about the sensory characteristics and underlying mechanisms behind secondary hyperalgesia (HA) (2° HA). The aim of the present study was to investigate the relationships between two different noxious stimuli, mechanical and cold on capsaicin-induced 2° HA. Fourteen healthy volunteers were exposed to three different cold stimuli (20, 10, 0°C) 30 s each, on both forearms. The cold stimuli were applied before (baseline) and 8 min after intradermal administration of 50-μg capsaicin to the forearm, distally to the injection site in the inspected area of 2° HA. Pain intensities were assessed immediately after each cold stimulus by means of a visual analogue scale (cold-VAS). Additionally, areas of mechanical HA (cm<superscript>2</superscript>) were assessed distally and proximally to the injection site at three different time points: 5, 8 (right after the second series of cold stimuli), and 30 min after the injection. No significant differences in cold-VAS were found between pre- and post-capsaicin injection at the tested forearm ( P= 0.334), whereas significant reduction from pre- to post-injection was found in cold-VAS in the control forearm ( P= 0.024). Further, 8 min after the injection, the cold stimulation led to an expansion of 2° HA area (from 5.1±1.38 to 11.4±1.72 cm<superscript>2</superscript>) to punctuate stimuli distally but not proximally to the injection site ( P<0.05). It is concluded that there is no HA to cold stimuli within the area of mechanical 2° HA. However, cooling acts as a conditioning stimulus and expands the area of capsaicin-induced punctuate HA. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00144819
- Volume :
- 170
- Issue :
- 1
- Database :
- Complementary Index
- Journal :
- Experimental Brain Research
- Publication Type :
- Academic Journal
- Accession number :
- 20004839
- Full Text :
- https://doi.org/10.1007/s00221-005-0185-9