European journal of pain : EJP
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Comparative Study
Coping strategies and beliefs about pain in veterans with comorbid chronic pain and significant levels of posttraumatic stress disorder symptoms.
The purpose of this study was to assess differences in beliefs about pain and coping strategies employed in veterans with comorbid chronic pain and posttraumatic stress disorder (PTSD), compared to veterans with chronic pain alone. It was hypothesized that veterans with comorbid chronic pain and significant levels of PTSD symptomatology would report higher levels of maladaptive coping strategies and beliefs about pain when compared to veterans with pain alone. ⋯ The results of this study suggest potential explanations for the previously observed negative effect of PTSD on chronic pain. Moreover, the results suggest specific targets for intervention with patients who have comorbid pain and PTSD.
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Sustained isometric muscle contraction (fatiguing contraction) recruits segmental and/or extrasegmental descending inhibition in healthy subjects but not in fibromyalgia (FM). We hypothesized that fatiguing contraction may shift descending pain modulation from inhibition towards facilitation and that the effect of descending pain modulation be dependent on peripheral muscle pain sensitivity. ⋯ Descending pain modulation shifts from descending inhibition towards descending facilitation following muscle nociception in FM. Peripheral mechanical hyperalgesia and descending facilitation counterbalance the effect of descending inhibition in FM.
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Pain has both sensory-discriminative and emotional-affective dimensions. Previous studies demonstrate that electroacupuncture (EA) alleviates the sensory dimension but do not address the affective. An inflammatory pain rat model, produced by a complete Freund adjuvant (CFA) injection into the hind paw, was combined with a conditioned place avoidance (CPA) test to determine whether EA inhibits spontaneous pain-induced affective response and, if so, to study the possibility that rostral anterior cingulate cortex (rACC) opioids underlie this effect. ⋯ EA treatment did not produce reward or aversive effect. Intra-rACC administration of D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr amide (CTOP), a selective mu opioid receptor antagonist, but not norbinaltorphimine (nor-BNI), a selective kappa opioid receptor antagonist, blocked EA inhibition of the affective dimension. These data demonstrate that EA activates opioid receptors in the rACC to inhibit pain-induced affective responses and that EA may be an effective therapy for both the sensory-discriminative and the affective dimensions of pain.
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Multicenter Study Comparative Study Clinical Trial
Evaluation of the comparative analgesic effectiveness of transdermal and oral opioids in cancer patients: a propensity score analysis.
Transdermal delivery systems containing fentanyl or buprenorphine, despite the relatively lack of comparative studies, have reached an impressive share of the market in several countries. In the context of a wider observational study, we applied the propensity score to test the comparative effectiveness of the two routes of administration (oral vs. transdermal). ⋯ The application of the propensity score has helped understand better the actual effectiveness of transdermal delivery systems that are at least equivalent to the oral opioids, and even more effective for pain intensity reduction.
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Recent studies demonstrated that patients with carpal tunnel syndrome (CTS) have signs of thermal and mechanical hyperalgesia in extra-median territories suggesting an involvement of central pain mechanisms. As previous studies included patients with shoulder/arm symptoms or neck pain, a potential influence of these coexisting disorders cannot be excluded. This study therefore evaluated whether widespread sensory changes (hypoesthesia or hyperalgesia) are present in patients with unilateral CTS in the absence of coexisting disorders. ⋯ This was especially apparent for heat pain ratings which were elevated not only in the affected hand but also in the neck and tibialis anterior muscle. In conclusion, CTS alone in the absence of coexisting neck and arm pain does not account for sensory changes outside the affected hand as determined by traditional QST threshold testing. Elevated pain ratings may however be an early indication of central pain mechanisms.