Hypnosis increases heat detection and heat pain thresholds in healthy volunteers.
OBJECTIVE
Hypnosis has been reported to induce analgesia and to facilitate anesthesia. To date, hypnotic-induced analgesia has had little explanation and it has even been questioned. The current study was thus designed to investigate the effect of hypnotic suggestion on thermal-detection thresholds, heat pain, and heat-pain tolerance thresholds.


METHODS
In 15 healthy volunteers, enrolled in a randomized cross-over study, thermal thresholds were investigated in 2 sequences of measurements, under waking and hypnotic states, using a thermal stimulator.


RESULTS
Heat detection and heat-pain thresholds were increased under hypnosis (from 34.3 +/-.9 degrees C to 36.0 +/- 2.9 degrees C and 45.0 +/- 3.7 degrees C to 46.7 +/- 2.7 degrees C, respectively, P <.05), whereas heat-pain tolerance and cold-detection thresholds were not statistically changed.


CONCLUSIONS
These results indicate that hypnosis may partly impair the detection of A delta and C fibers stimulation, potentially explaining its analgesic effect.
Langlade
Agnès
A
Anesthetic Department and Pain Clinic, Tenon Hospital, Assistance Publique Hôpitaux de Paris, Paris, France.
Jussiau
Claire
C
Lamonerie
Laurent
L
Marret
Emmanuel
E
Bonnet
Francis
F
D000328:Adult; D003080:Cold Temperature; D018592:Cross-Over Studies; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006991:Hypnosis, Anesthetic; D008297:Male; D008875:Middle Aged; D017288:Pain Threshold; D012016:Reference Values; D012684:Sensory Thresholds