Pain
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Sex differences in chronic pain are reported to emerge during adolescence, although it is unclear if this includes responses to treatment. We conducted a meta-analysis to examine whether sex differences were present on outcome variables at pre-treatment, and whether the efficacy of psychological therapies for pediatric chronic pain differs between boys and girls at post-treatment and follow-up time points. Searches were conducted, extending two existing Cochrane reviews of randomized-controlled trials examining the efficacy of psychological therapies for chronic and recurrent pain in children and adolescents. ⋯ Treatment gains were consistent across the sexes. One exception was for post-treatment disability in children with non-headache pain conditions; girls exhibited a significant effect of treatment relative to control condition (SMD= -0.50[-0.80,-0.20], p < .01), but no such effect was observed for boys (SMD= -0.08[-0.44,0.28], p = .66). Future research should examine whether mechanisms of treatment efficacy differ between boys and girls, and consider the impact of pre-treatment sex differences on response to treatment.
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Withdrawal pain can be a barrier to opioid cessation. Yet, little is known about old injury site pain in this context. We conducted an exploratory mixed-methods descriptive case series using a web-based survey and in-person interviews with adults recruited from pain and addiction treatment and research settings. ⋯ Fifteen surveyed participants (44%) reported returning to opioid use because of WISP in the past. Participants developed theories about the etiology of WISP, including that the pain is the brain's way of communicating a desire for opioids. This research represents the first known documentation that previously healed, and pain-free injury sites can temporarily become painful again during opioid withdrawal, an experience which may be a barrier to opioid cessation, and a contributor to opioid reinitiation.
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Cannabinoids may hold potential for the management of rheumatic pain. Arthritis, often self-reported, is commonly cited as the reason for the use of medicinal herbal cannabis (marijuana). We have examined the prevalence of marijuana use among 1000 consecutive rheumatology patients with a rheumatologist-confirmed diagnosis and compared in an exploratory manner the clinical characteristics of medicinal users and nonusers. ⋯ Therefore, less than 3% of rheumatology patients reported current use of medicinal marijuana. This low rate of use in patients with a rheumatologist-confirmed diagnosis is in stark contrast to the high rates of severe arthritis frequently reported by medicinal marijuana users, especially in Canada. Familiarity with marijuana as a recreational product may explain use for some as disease status was similar for both groups.
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The increasing availability of "big data" enables novel research approaches to chronic pain while also requiring novel techniques for data mining and knowledge discovery. We used machine learning to combine the knowledge about n = 535 genes identified empirically as relevant to pain with the knowledge about the functions of thousands of genes. Starting from an accepted description of chronic pain as displaying systemic features described by the terms "learning" and "neuronal plasticity," a functional genomics analysis proposed that among the functions of the 535 "pain genes," the biological processes "learning or memory" (P = 8.6 × 10) and "nervous system development" (P = 2.4 × 10) are statistically significantly overrepresented as compared with the annotations to these processes expected by chance. ⋯ Published empirical evidence supporting their involvement in chronic pain was identified for almost all these genes, including 1 gene identified in March 2016 as being involved in pain. By contrast, such evidence was virtually absent in a randomly selected set of 34 other human genes. Hence, the present computational functional genomics-based method can be used for candidate gene selection, providing an alternative to established methods.