The journal of pain : official journal of the American Pain Society
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Females are disproportionately affected by irritable bowel syndrome (IBS) with menstrual cycle-dependent fluctuations in abdominal pain suggesting a role for ovarian hormones. IBS patients also exhibit greater activation of brain areas involved in pain affect such as the amygdala, yet the role of supraspinal processes in the effects of ovarian hormones on visceral pain is largely unexplored. The goal of the current study was to determine whether sex steroids act at the level of the amygdala to alter colonic pain sensitivity. Ovariectomized rats received implants on the amygdala of progesterone, estradiol, progesterone combined with estradiol, or cholesterol as a control to examine the involvement of the amygdala in ovarian hormone-mediated changes in visceral sensitivity. Visceral sensitivity was quantified as the number of abdominal contractions, a visceromotor response (VMR), in response to graded pressures of colorectal distension (CRD). Somatic sensitivity was also assessed by measuring the mechanical force required to elicit hindpaw withdrawal. Elevated levels of progesterone and/or estradiol on the amygdala heightened the responsiveness to CRD; in contrast, neither estradiol nor progesterone altered somatic sensation. Furthermore, administration of progesterone or estradiol to areas adjacent to the amygdala did not affect visceral sensitivity. Future studies will address the specific steroid receptors mediating the effects of progesterone and estradiol. ⋯ To our knowledge, this study represents the first description of a specific brain site mediating the effects of ovarian steroids on visceral sensitivity. These data also suggest that an amygdala-dependent mechanism may be responsible, at least in part, for the exacerbation of visceral symptomatology in females.
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The prevalence of pain and pain undertreatment in older persons, along with the many potential detrimental consequences of undertreated pain, pose a substantial burden to the individual, their family, and society. An accurate pain assessment is the foundation for treating pain; yet, thorough pain assessments and regular reassessments are too often neglected. Older adults typically present with multiple pain etiologies, making it all the more imperative that a comprehensive assessment is conducted. ⋯ Following an unsuccessful attempt at self-report from a nonverbal older adult, the potential causes of pain should be explored. Direct observation can then be used to identify behaviors suggestive of pain, and the patient's response to an analgesic trial can be observed. A pain behavior tool can also provide useful information suggesting the presence of pain.
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Evidence of support for sensory changes during minor depression and sadness is scarce and the neural mechanisms are unclear. We assessed central pain processing engaged in nociceptive C-fiber polymodal activity by examining the perception of a non-noxious unpleasant burning sensation induced by a thermal grill illusion, in 26 nonpatients with minor depression (19 females) and 28 healthy subjects (18 females), between 19 and 61 years old and pain free at the study. Controls were also subjected to induction of transient moods. Subjects with depression reported increased pain perception; this increase was more pronounced for the affective dimension of pain (unpleasantness) than for its sensory dimension (intensity). The perception of pain unpleasantness, pain intensity, and overall pain showed positive and linear correlations with depression levels measured by Zung's and Beck's scales. In controls, sad mood induction only increased the scores assigned to negative mood-describing adjectives; the perception of pain intensity, unpleasantness, and overall pain were significantly increased following sad, but not neutral or elevated, mood inductions. Yet, pain intensity and unpleasantness were correlated linearly and reciprocally to positive, instead of negative, mood-describing adjective scores. Thus, there is a central thermal hyperalgesia in subjects with minor depression and sadness. ⋯ There is a central thermal hyperalgesia in subjects with minor depression, probably associated with an enhanced central processing of nociceptive C-fiber polymodal activity at anterior cingulate cortex, that is predominately expressed as an increased unpleasantness and that could be in part counteracted by behavioral therapies leading to mood elevation.
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Acupuncture is a widely used symptomatic treatment for carpal tunnel syndrome (CTS). The objective of this systematic review was to evaluate the evidence of the effectiveness of acupuncture and acupuncture-like treatments for CTS. Systematic searches were conducted on 11 electronic databases without language restrictions. All randomized controlled trials (RCTs) of acupuncture as a treatment of CTS were included. Methodological quality was assessed using the Cochrane risk of bias tool. Six RCTs met our inclusion criteria. Their methodological quality was generally low. Two RCTs compared the effectiveness of acupuncture with a sham control. The others used active controls. A meta-analysis of acupuncture versus steroid block therapy favored acupuncture (2 studies, n = 144; risk ratio, 1.28; 95% CI, 1.08 to 1.52; P = .005; heterogeneity, I(2) = 10%) in terms of responder rate. Our systematic review and meta-analysis demonstrate that the evidence for acupuncture as a symptomatic therapy of CTS is encouraging but not convincing. The total number of included RCTs and their methodological quality were low. Further rigorous studies are required to establish whether acupuncture has therapeutic value for this indication. ⋯ This systematic review of RCTs focused on clinical trials testing the effectiveness of acupuncture for CTS. The existing evidence is not convincing enough to suggest that acupuncture is an effective therapy for CTS. Further RCTs should overcome the limitation of previous studies.