Pain
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Spinal cord injury (SCI) results in deafferentation and the onset of neuropathic pain in a substantial proportion of people. Based on evidence suggesting motor cortex activation results in attenuation of neuropathic pain, we sought to determine whether neuropathic SCI pain could be modified by imagined movements of the foot. Fifteen subjects with a complete thoracic SCI (7 with below-level neuropathic pain and 8 without pain) were instructed in the use of movement imagery. ⋯ Two subjects without a history of pain or non-painful phantom sensations had onset of dysesthesia while performing imagined movements. This study reports exacerbation of pain in response to imagined movements and it contrasts with reports of pain reduction in people with peripheral neuropathic pain. The potential mechanisms underlying this sensory enhancement with movement imagery are discussed.
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This study examined within- and across-session consistency of visual analog scale (VAS) pain intensity and unpleasantness ratings of contact heat stimuli in 64 subjects (32 male). Subjects participated in four sessions over 14 days, with three stimulus series per session. Two levels of painful heat (pain-lo: rated 40, and pain-hi: rated 70 on a 0-100 VAS) were delivered in randomized order during each series, with temperatures selected on an individual subject basis to equalize pain perception across subjects. ⋯ Across- and within-session CVs were significantly negatively correlated with individual ratings of the stimuli, but were not correlated with demographic or psychosocial factors. Furthermore, sex did not impact consistency of ratings, demonstrating that neither sex is more variable in ratings than the other over time. Taken together, these findings suggest that VAS ratings of painful contact heat are relatively stable over time but the variability of these ratings is significantly impacted by the perceived intensity of the stimulus.
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The aims of this study were to replicate and extend previous observations on the relationship between enmeshment of the self and pain and measures of adjustment [Morley et al., Possible selves in chronic pain: self-pain enmeshment, adjustment and acceptance, Pain 2005;115:84-94], and to test the hypothesis that individual variation in motivational preferences interacts with enmeshment. 82 chronic pain patients completed standardized self-report measures of depression, anxiety, acceptance and the possible selves interview which generated measures of their hoped-for (own and other perspectives) and feared-for selves. They made judgments about the conditionality of each self on the continuing presence of pain as a measure of self-pain enmeshment. A series of hierarchical regression analyses, that adjusted for demographics, pain characteristics and disability, confirmed the relationship between self enmeshment and depression and acceptance. When anxiety was considered, there was no main effect for any of the self aspects but there were specific interactions between the hoped-for (own) and (other) selves and two motivational preferences--autonomy and sociotropy.
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The aim of the present study is to get an insight into the pain report of children over two sequential dental visits. Furthermore, it was studied whether age, previous dental experience, level of dental anxiety and injection site were of influence on the self-reported pain of children during the first and second treatment session. One hundred and forty-seven children (4-11 years old) were included in the study. ⋯ For the older children, the children having previous dental experience gave the highest pain ratings on the first treatment session. Furthermore, for both young and older children the amount of pain reported for the second injection was best predicted by the amount of pain reported for the first injection, whereby higher scores the first time predict higher scores the second time. In conclusion, the memory of previous experience with dentistry and earlier treatment sessions seems of great influence on the behaviour and the experience of children during subsequent treatment sessions.
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This study investigated the effect of haeme oxygenase-1 (HO-1) in nociception induced by formalin injection in the mice hind paw. Intraperitoneal (i.p.) administration of cobalt protoporphyrin (CoPP, an HO-1 inducer, 5mg/kg) 24h before the test, inhibited the nociceptive response during the second phase, but not during the first phase of the formalin test. The effect of CoPP was prevented by treatment with tin protoporphyrin (SnPP, an inhibitor of HO-1 activity) administered either by i.p. (25mg/kg, 30 min before the test) or intraplantar (400 nmol/paw, 5 min before the test) routes. ⋯ In conclusion, Nrf2-mediated HO-1 expression induced an antinociceptive effect at peripheral sites. These results suggest that HO-1 modulates the inflammatory pain pathways. Hence, the development of drugs that could raise peripheral HO-1 could be relevant in inflammatory pain treatment.