Insensitivity to pain: electrophysiological study of the nociceptive reflex. Influence of naloxone
Dehen, H.; Willer, J.C.; Prier, S.; Boureau, F.; Gonce, M.; Cambier, J.
Revue Neurologique (Paris) 134(4): 255-262
1978
ISSN/ISBN: 0035-3787 PMID: 82987 Document Number: 135843
Electrophysiological studies of the nociceptive reflex (R3) were carried out in eight normal subjects, and one patient with congenital insensitivity to pain, in order to compare the effects of naloxone and a placebo. No significant variation in the reflex threshold was seen in the normal subjects. Two electrophysiological abnormalities were observed in the patient: a 350 per cent spontaneous elevation in the R3 threshold compared to the control group; a rapid and large drop (67 per cent) in the threshold lasting for about ten minutes after the injection of Naloxone. These results suggest that in this particular case the insensitivity to pain could be related to the permanent hyperactivity of a morphine-like inhibitory system.