Stress and thermoregulation: Different sympathetic responses and different effects on experimental pain

Abstract

Stress and thermoregulation both activate the sympathetic nervous system (SNS) but might differently affect pain. Studies investigating possible interactions in patients are problematic because of the high prevalence of SNS disturbances in patients. We therefore analyzed the influence of these different sympathetic challenges on experimentally-induced pain in healthy subjects. SNS was activated in two different ways: by mental stress (Stroop task, mental arithmetic task), and by thermoregulatory stimulation using a water-perfused thermal suit (7 degrees C, 32 degrees C, or 50 degrees C). Attentional effects of the mental stress tasks were controlled by using easy control tasks. Both, stress and thermoregulatory stimuli, robustly activated SNS parameters. However, the patterns of activation were different. While stress co-activated heart rate, blood pressure, peripheral vasoconstriction and sweating, thermal stimulation either increased blood pressure (cold) or heart rate and sweating (warm). Only stress was able to induce a significant reduction of pain. The control tasks neither activated the SNS nor altered pain perception. Our results suggest that (1) different patterns of sympathetic activation can be recorded after stress and thermoregulatory challenges and (2) that only stress is able to interfere with sensation of experimental pain. Whether SNS activation is causally responsible for analgesia needs to be further investigated.

Brain temperature in volunteers subjected to intranasal cooling

“…Both cooling and stress associated with the procedure can induce peripheral vasoconstriction [29,30]. A mean forearm-finger temperature difference higher than 0°C is a sign of thermoregulatory peripheral vasoconstriction [31].…”

Analysis of Interdependencies Between Students’ Emotions, Learning Productivity, Academic Achievements and Physiological Parameters / Studentų Emocijų, Mokymosi Produktyvumo, Akademinių Pasiekimų Ir Fiziologinių Parametrų Ryšių Analizė

“…The research of Kamei et al (1998) also indicates that the sweat rate significantly increased during mental arithmetic. Fechir et al (2009) argue that the effect of "stress" on emotional sweating revealed that difficult mental arithmetic induced stronger emotional sweating than the easy task. Emotional sweating increased during mental arithmetic tasks.…”

“…Kobayashi et al (2003), Kamei et al (1998) analysed the interdependences linking arithmetic calculations with human palm humidity and sweating, while Fechir et al (2009) analysed the interdependencies linking mental stress to sweat rate. The said authors point out that arithmetic calculations and the intensity of mental stress cause an increase of human palm humidity and sweating.…”

“…Kobayashi et al (2003), Kamei et al (1998), and Fechir et al (2009) analysed changing skin humidity parameters caused by changing intensity of mental activity. Fechir et al (2009), Harrís et al (2000, Vuksanovic and Gal (2007), Murata et al (1999), Sloan et al (1991), Tumer et al (1987), Szabo et al (1994), Tañida et al (2004), Furedy et al (1996) examine the interdependence between the heart rate and the mental stress (arithmetic stress). Fechir et al (2009), Harrís et al (2000, Sloan et al (1991) investigated the changes in blood pressure caused by changing intensity of mental activity.…”

Natural Wool Fabrics in Physiotherapy

“…Longterm emotional stress may act as an additional factor activating the sympathetic nervous system; it often underlies psychosomatic syndromes including locomotor organ disorders. Dry or moist heat application provides therapeutic benefits (Fechir et al, 2009). …”