Pain
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Clinical Trial
The influence of communication goals and physical demands on different dimensions of pain behavior.
The purpose of the present research was to examine the influence of communication goals and physical demands on the expression of communicative (e.g., facial grimaces) and protective (e.g., guarding) pain behaviors. Participants with musculoskeletal conditions (N=50) were asked to lift a series of weights under two communication goal conditions. In one condition, participants were asked to estimate the weight of the object they lifted. ⋯ The results of this study support the functional distinctiveness of different forms of pain behavior. Findings are discussed in terms of evolutionary and learning theory models of pain behavior. Clinical implications of the findings are addressed.
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Although evidence reveals that self-efficacy is associated with disability in people with pain, there is less known about this relationship in primary care settings and no published information in general population samples. This study aimed to assess the relationship between pain, self-efficacy, health-related quality of life, psychological distress and disability in a general population sample. A randomly selected sample from electoral registers of the lower North Island of New Zealand was mailed a survey questionnaire. ⋯ This interaction was not observed for health self-efficacy. General self-efficacy was more strongly related to psychological distress and this association was not influenced by pain status. Health-related quality of life was associated with health self-efficacy but not general self-efficacy.
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Clonidine is approved for spinal administration against neuropathic pain, and reverses both spontaneous and elicited pain in humans following spinal administration. Rodent studies that seek to model pharmacology in pain states have historically relied on reflexive withdrawal from noxious stimuli as the primary endpoint. Drug self-administration studies have face validity in the drug abuse field for modeling drug abuse in humans, however, this methodology has not been applied to address issues related to drug seeking behaviors that may be relevant for other human populations, such as patients with neuropathic pain. ⋯ Substitution of clonidine with saline or with clonidine and the alpha2-adrenoceptor antagonist idazoxan resulted in extinction of responding in SNL animals. Food reinforcement was initially decreased in SNL rats self-administering clonidine compared to normal animals, however, tolerance developed to this effect of clonidine in SNL rats after 5 days. These data demonstrate that drug self-administration can be applied to questions other than drug abuse, and provides an additional measure for development of novel therapeutic strategies for chronic pain treatment.
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Surgical procedures associated with tissue injury are often followed by increased sensitivity to innocuous and noxious stimuli in the vicinity of the surgical wound. The aim of this study was to evaluate the role of transient receptor potential vanilloid 1 receptor (TRPV1) containing nociceptors in this process, by their functional inactivation using a high-concentration intradermal injection of capsaicin in a rat plantar incision model. Paw withdrawal responses to mechanical stimuli (von Frey filaments 10-367mN) and to radiant heat applied on plantar skin were tested in animals treated with capsaicin or the vehicle 6 days and 24h before or 2h after the incision was made. ⋯ Capsaicin application 6 days before the incision induced thermal hypoalgesia before the incision but did not prevent completely the thermal hyperalgesia after the incision, while there was also a reduction of mechanical hypersensitivity. Application of the capsaicin injection after the incision showed its first effect at 2h after the injection and at 24h the effect was comparable with the 6 days pretreatment. Our results show an important role of TRPV1-containing nociceptors in the development of post-surgical hypersensitivity and suggest that local, high-concentration capsaicin treatment could be used to reduce it.