Gender Differences in Heat Pain and Temporal Summation Threshold in Normal Volunteers

Lee, Joon Ho; Yoo, Jae Hwa; Cho, Sung Hwan; Kim, Yong Ik

Abstract

BACKGROUND
Females generally have a lower pain and temporal summation threshold than men. However, the results of studies designed to evaluate gender differences in the thresholds of heat pain and the temporal summation have been inconsistent. Newly developed device, CHEPS (Contact Heat Evoked Potential Stimulation) model of PATHWAY, have superiority on its fast rise and return time in temperature. Therefore we investigated gender differences in heat pain and temporal summation threshold. METHODS: Forty healthy volunteers (20 males and 20 females) were enrolled in this study. A thermode was applied to the volar side of each volunteer's left forearm and heat pain and the temporal summation threshold was then measured. The heat pain threshold was estimated using the staircase method by starting from 36degrees C and then increasing the temperature in 0.5degrees C increments. The temporal summation threshold was estimated by applying five successive stimulation of the same temperature starting at 2degrees C lower than the heat pain threshold and then increasing the temperature in 0.5degrees C increments. RESULTS: The mean heat pain thresholds was found to be 41.63 +/- 1.63degrees C for males and 41.60 +/- 1.84degrees C for females and the temporal summation thresholds were found to be 40.83 +/- 1.64degrees C for males and 40.77 +/- 1.93degrees C for females. The differences between males and females were not statistically significant. CONCLUSIONS: The result of this study suggested that there are no gender differences in heat pain and temporal summation threshold.