JMIR Publications

ABSTRACT

Background:

Virtual reality hypnosis (VRH) is a promising tool to reduce pain. However, VRH benefits on pain perception and on the physiological expression of pain still require further investigation.

Objective:

In this study, we characterized the effects of VRH on heat pain threshold in adult healthy volunteers and simultaneously monitored several physiological and autonomic functions.

Methods:

60 healthy volunteers were prospectively included to receive nociceptive stimulations. The first series of thermal stimuli consisted of 20 stimulations at 60°C (duration: 500 ms) to trigger contact heat evoked potentials (CHEPs). The second series of thermal stimuli consisted of temperature ramps (1°C/sec) to determine the thermal pain thresholds of the participants. Electrocardiogram, electrodermal conduction, respiration rate as well as the analgesia nociception index were also recorded throughout the experiment.

Results:

Data from 58 participants were analysed. There was a significant increase in pain threshold in VRH compared to NoVRH (p<0.001, Wilcoxon matched-pairs signed ranks). No significant effect of VRH on CHEPs and heart rate parameters was observed. Compared to control, VRH subjects display a clear reduction in their autonomic sympathetic tone as seen by the low number of non-specific skin conductance peak responses (p = 0.0007, 2-way ANOVA) and the analgesia nociception index increase (p = 0.0005; paired t-test).

Conclusions:

The results obtained in this study support the idea that VRH administration to healthy volunteers is effective at increasing heat pain thresholds and impacts autonomic functions. As a non-pharmacological intervention, VRH has beneficial action on acute experimental heat pain. This beneficial action will now need to be evaluated for the treatment of other types of pain including chronic pain.