Sex Hormones and Pain: The Evidence From Functional Imaging

Abstract

There is a substantial body of epidemiological and clinical evidence suggesting that the sex hormones, particularly estradiol and progesterone, play a role in pain. Behavioral studies have not been useful in understanding the relationship between sex hormones and pain perception, and certainly have not helped to elucidate the mechanisms by which such effects may be mediated. This review aims to address the additional insights functional imaging has given us into the role of sex hormones in pain. Functional imaging techniques and experimental designs are discussed before the literature investigating specific questions relating to hormones and pain is reviewed. Finally, we conclude by considering how results of studies imaging the influence of sex hormones in related areas such as emotion and cognition also may inform our understanding of this complex area.

Amygdala activity contributes to the dissociative effect of cannabis on pain perception

“…Women were excluded as the experimental drug study lasts about 4–6 weeks, and there is clear evidence for the potentially confounding effects of menstruation-related hormone fluctuations on pain in that month-long test period [59]. All subjects gave written informed consent and were familiarised with experimental procedures.…”

Biological and psychological predictors of visceral pain sensitivity in healthy premenopausal women

“…In order to homogenize our sample, only female subjects on hormonal contraceptives were studied to reduce potential confounding by menstrual cycle phase given previously described effects of ovarian hormones on pain and IBS (Vincent and Tracey, ; Craft, ; Heitkemper and Chang, ). Information about the type of hormonal contraceptive (i.e., biphasic or triphasic) was however not recorded for all participants.…”

Sex‐based differences in brain alterations across chronic pain conditions

“…An additional area in which a lack of research may be creating a barrier to progress concerns sex hormones. Sex hormones are well known to influence pain perception, with estradiol having both pronociceptive and antinociceptive actions, whereas testosterone appears to be mainly antinociceptive in both males and females (Aloisi and Bonifazi, 2006;Craft, 2007;Vincent and Tracey, 2010). Although the importance of studying sex hormone-related effects is most obvious in menstrual pain-related syndromes, many other chronic pain patients demonstrate cycle-related or menopause-related changes in symptom severity (Heitkemper and Chang, 2009;Martin, 2009).…”