Articles: chronic-pain.
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Alexithymia, or a lack of emotional awareness, is prevalent in some chronic pain conditions and has been linked to poor recognition of others' emotions. Recognising others' emotions from their facial expression involves both emotional and motor processing, but the possible contribution of motor disruption has not been considered. It is possible that poor performance on emotional recognition tasks could reflect problems with emotional processing, motor processing or both. ⋯ Participants who were more accurate at one task were also more accurate at the other, regardless of group (P < 0·001, r(2) = 0·523). Participants with chronic facial pain were worse than controls at both the FEEL emotion recognition task and the left/right facial expression task and performance covaried within participants. We propose that disrupted motor processing may underpin or at least contribute to the difficulty that facial pain patients have in emotion recognition and that further research that tests this proposal is warranted.
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Chronic pain is a major characteristic feature of sickle cell disease (SCD). The refractory nature of pain and the development of chronic pain syndromes in many patients with SCD suggest that central neural mechanisms contribute to pain in this disease. We used HbSS-BERK sickle mice, which show chronic features of pain similar to those observed in SCD, and determined whether sensitization of nociceptive neurons in the spinal cord contributes to pain and hyperalgesia in SCD. ⋯ Compared with control HbAA-BERK mice, nociceptive dorsal horn neurons in sickle mice exhibited enhanced excitability as evidenced by enlarged receptive fields, increased rate of spontaneous activity, lower mechanical thresholds, enhanced responses to mechanical stimuli, and prolonged afterdischarges following mechanical stimulation. These changes were accompanied by increased phosphorylation of mitogen-activated protein kinases (MAPKs) in the spinal cord that are known to contribute to neuronal hyperexcitability, including c-Jun N-terminal kinase (JNK), p44/p42 extracellular signaling-regulated kinase (ERK), and p38. These findings demonstrate that central sensitization contributes to pain in SCD.
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Pain drawings have frequently been used for documentation of pain and a convenient diagnosis tool. Pain drawings were found to be associated with psychological states in chronic patients with low back pain. Few researchers have investigated pain drawings except in low back pain. The aim of this study was to investigate the pain, pain drawings, psychological characteristics, and pain interference in the head, neck-shoulder (NS), and low-back/lower-limb (LB-LL) regions among patients with chronic pain. ⋯ Our results suggest that the characteristics of patients with nonorganic drawings differ according to body regions.
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Opioids are well known for their robust analgesic effects. Chronic activation of mu opioid receptors (MOPs) is, however, accompanied by various unwanted effects such as analgesic tolerance. Among other mechanisms, interactions between MOPs and delta opioid receptors (DOPs) are thought to play an important role in morphine-induced behavioral adaptations. ⋯ As opposed to NTI, 7-benzylidenenaltrexone and naltriben were reported to be selective DOP subtype 1 and DOP subtype 2 antagonists, respectively. Interestingly, naltriben but not 7-benzylidenenaltrexone was able to attenuate the development of morphine analgesic tolerance in inflamed rats. Altogether, our results suggest that targeting of DOP subtype 2 with antagonists provides a valuable strategy to attenuate the analgesic tolerance that develops after repeated morphine administration in the setting of chronic inflammatory pain.
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Although sleep disorder is one of the most serious comorbidities of refractory chronic pain, it is usually assessed only from the patients' subjective point of view. Therefore, we aimed to objectively evaluate the sleep efficiency of patients with chronic pain. ⋯ With the use of an actigraph, improvements in sleep of patients with chronic pain undergoing SCS were demonstrated. One case showing improvement in sleep despite pain palliation may suggest that SCS might have independently affected the sleep system, although further studies are necessary.