Perceptual and Motor Skills, 1992, 74, 737-738.

O Perceptual and Motor Skills 1992

INCREASE IN CUTANEOUS TEMPERATURE INDUCED BY HYPNOTIC SUGGESTION OF PAIN l? H ~ E K B. , JAKOUBEK, K. ~ H O S AND , T. RADIL Czechoslovak Academy of Sciences Institute of Physiology, Prague Summary.-Eight patients with atopic eczema and six healthy subjects were given hypnotic suggestion to feel pain in the upper part of the back and in one case on the palm. An average local increase in skin temperature of 0.6O C (detected by thermovision) occurred under this condition. For some patients cutaneous pain threshold was increased before the experiment by means of repetitive hypnotic suggestion of analgesia. These subjects reported feeling no pain subjectively, but the local change in slun temperature was equal in both cases. The results suggest a central mechanism induced by measuring changes in pain threshold in the skin, which changes are independent of local changes in blood flow. A gradual and long-lasting increase in cutaneous pain threshold was observed in patients with atopic eczema (with strong itching and pain) and in healthy subjects after repeated hypnotic suggestions (HBjek, Jakoubek, & Radil, 1990). The findings suggested that the changes in cutaneous pain threshold induced by hypnosis occur in the central nervous system. In the present experiments the question of interest was whether local changes accompanying pain Ln the skin are a f e r e n c (i.e., less prominent) during long-lasting analgesia induced by specific suggestions made during repetitive hypnotic sessions. E~ghcpatients with atopic eczema were on the average 26.4 yr. old and the average duration of their disease was 20.4 yr. Six healthy subjects (whose average age was 18.6 yr) also participated in the experiment. Local pain in the middle of the upper part of the back, and in one subject for comparative purposes in the region of the right palm, was induced during a single hypnotic session by specific suggestion which emphasized a subjective feeling of local pain lasting for 6 minutes. In four of the eczema patients long-lasting cutaneous analgesia was induced before this experiment by a different suggestion which stressed the impossibility of conducting pain from the skin to the brain and which was repeated in ten consecutive hypnotic sessions (Hijek, Jakoubek, & Radil, 1991). Hypnability (measured on the Stanford scale) was estimated before the experiment, average values for the patients with atopic eczema and healthy subjects being 8.2 and 7.6 points, respectively. The spatial thermal reaction of the skin surface after the suggestion of pain was monitored by means of thermovision (AGA thermovision System 680). Consecutive recordings were taken at 20-sec. intervals before and after finishing the hypnotic suggestion of pain. I n both the eczema patients with normal skin sensitivity and healthy individuals the subjective feeling of pain was accompanied by a gradual increase in skin temperature (M = 0.6' C) spreading over the area in question (Fig. I), apparently caused by changes in blood flow. The changes observed on the palm were similar to those for the back. T e h c a l conditions of the experiment allowed measurement of neither temporal and spatial aspects of the spreading of the thermal wave nor differences among various skin areas. In the four eczema patients with long-lasting cutaneous analgesia treated equally, the thermal reaction of the skin was similar to that described above although no subjective feeling of 'Address requests for reprints tp Tomij: Radil, Czechoslovak Academy of Sciences, Institute of Physiology, 142 20 Praha 4-KRC, Vfdehski 1083, Czechoslovakia.

P. HAJEK, ET AL.

B

Temperature OC

136.8 36.6 36.4

FIG 1 Increase of cutaneous temperature spreading over the back as induced by an hypnotic suggestion of pain in the corresponding area A (before hypnosis), B (first minute of hypnotrc p a n suggestion), C (third minute of hypnotic pain suggestion, and D (sixth minute of hypnoclc pa^ suggestion. Lntervals between measurements during hypnosis were 20 sec. pain was reported. These subjects reported feeling only that their skin was getting warmer at the spec~fiedplace. From these results, it follows that the mechanisms affected by the hypnotic suggest~onsdetermining changes in the perception of pain are central and independent of local changes in blood-flow.

REFERENCES HAJEK,

P., JAKOULIEK, B.,

& ~ I L T., (1990) Graduate increase in cutaneous threshold induced

HAJEK,

and Motor SkilCr, 70, 549-550. P., JAKOUBEK, B., & RADIL,T. (1991)

by repeated hypnosis of healthy individuals and patients with atopic eczema. Perceptual Hypnotic skin analgesy in healthy individuals and patients with atopic eczema. Homeostnsis, 33, 156-157.

Accepted April 2, 1992,

Increase in cutaneous temperature induced by hypnotic suggestion of pain.

Eight patients with atopic eczema and six healthy subjects were given hypnotic suggestion to feel pain in the upper part of the back and in one case o...
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