A preliminary report on pain thresholds in bulimia nervosa during a bulimic episode

Subjects with bulimia nervosa (BN) have been shown to exhibit abnormal sati ety responses, Short-term satiety is largely mediated by afferent vagal act ivity. Activation of afferent vagal fibers has also been found to stimulate a descending pain inhibitory pathway that leads to elevation in somatosens ory pain thresholds. Therefore, the study of pain thresholds in BN subjects may lead to a better understanding of afferent vagal function in this diso rder. In this preliminary study pressure pain thresholds were assessed in n ine subjects with BN on 3 consecutive days during a binge-eating and vomiti ng (B/V) episode, during a normal meal, and after an overnight fast. A sign ificant time versus condition effect was found with a significant change in the pain threshold in BN subjects under the B/V condition only. These data are consistent with the hypothesis that vagal afferent activation by a B/V episode also activates the descending pain inhibitory pathway. Copyrights (C) 1999 by W.B. Saunders Company.