Quantification of heat threshold and tolerance to evaluate small fiber neuropathy- an indigenously developed thermal model of pain

Abstract

Introduction: A wide variety of diseases alter the perceptions of different sensations, often evaluated in a subjective manner. Assessment of temperature perception and tolerance is a useful screening tool to evaluate the Degenerative and neuropathic changes of an individual. Therefore the current study was intended to design and develop an inexpensive device to quantify the heat threshold and tolerance in healthy participants. Materials and methods: The study was carried out in 30 apparent healthy participants for heat threshold, and tolerance was recorded on both hands' thenar and dorsal sites on two occasions. The minimum temperature when the subject was perceived is threshold and maximum until the subject withstood tolerance. The data was collected using the electronically controlled device for these two extremes. The entire study was carried out at a controlled room temperature precisely. Results: The heat threshold was 39.84 ± 2.33 °C, and the tolerance was perceived at 46.84 ± 3.36 °C. There were no intraindividual differences (p > 0.05) in the heat threshold measured on two different periods as well as between the two hands (p > 0.05). As expected, there were significantly higher threshold values on the palm's thenar aspect than dorsum (p < 0.05). The tolerance was significantly higher in the thenar aspect than the dorsum of both hands. (p < 0.01, p-0.03). There were no significant inter-hand differences of both surfaces of the hand. Conclusion: Our study showed that the results of threshold and tolerance using the indigenously built device were consistent and reproducible proves the robustness of the methodology. It is a cost-effective and user-friendly device that provides quantitative results of temperature extremes.

Keywords

• Minimum heat threshold
• Maximum heat tolerance
• Small fiber neuropathy
• Thermal model of pain