Pain
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Clinical Trial
Investigating the relationship between pain and discomfort and quality of life, using the WHOQOL.
The aim of this study was to examine the impact of pain on quality of life and its components in a representative sample of 320 well people, and patients selected from all major categories of illness. Quality of life was assessed using a new, multidimensional, multilingual, generic profile designed for cross-cultural use in health care, i.e. the WHOQOL. Within the WHOQOL, pain and discomfort is one of 29 areas or facets of quality of life, grouped into six domains. ⋯ Intense affective pain is particularly detrimental to a good quality of life. The psychometric properties of the pain and discomfort facet of the WHOQOL and WHOQOL-100 were assessed. Internal consistency (reliability), discriminant and criterion/concurrent validity were found to be good to excellent, justifying the use of this instrument with a range of chronic and acute pain patients.
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The aim of the study was to examine the presence of hyperalgesia to heat stimuli within the zone of secondary hyperalgesia to punctate mechanical stimuli. A burn was produced on the medial part of the non-dominant crus in 15 healthy volunteers with a 50 x 25 mm thermode (47 degrees C, 7 min), and assessments were made 70 min and 40 min before, and 0, 1, and 2 h after the burn injury. Hyperalgesia to mechanical and heat stimuli were examined by von Frey hairs and contact thermodes (3.75 and 12.5 cm2), and pain responses were rated with a visual analog scale (0-100). ⋯ Further, the heat pain response was more intense in the zone of primary hyperalgesia than in the zone of secondary hyperalgesia (P = 0.004), in contrast to the mechanical pain response, which was not significantly different between the two zones of hyperalgesia. In conclusion, secondary hyperalgesia in man is not restricted to mechanical stimuli, as significant hyperalgesia to heat developed within the zone of secondary hyperalgesia to punctate mechanical stimuli. The data, combined with other evidence, suggest differences in the mechanisms accounting for primary hyperalgesia to heat and mechanical stimuli, whereas secondary hyperalgesia to heat and mechanical stimuli may be explained by a common central mechanism.
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Comparative Study
Anti-hyperalgesic and anti-allodynic effects of intrathecal nociceptin/orphanin FQ in rats after spinal cord injury, peripheral nerve injury and inflammation.
We examined the effects of intrathecal nociceptin, the endogenous ligand for the orphan opioid receptor-like receptor, on abnormal pain-related behaviors in rats after carrageenan-induced inflammation and photochemically-induced peripheral nerve or spinal cord ischemic injury. Intrathecal nociceptin dose-dependently alleviated mechanical and cold allodynia-like behavior in the two models of neuropathic pain. The heat hyperalgesia associated with peripheral inflammation was also significantly reduced, although the efficacy of the antihyperalgesic effect of nociceptin in the inflammation model was decreased. ⋯ However, the antinociceptive effect of nociceptin was significantly reduced in rats with peripheral nerve injury. These results indicated that spinally administered nociceptin has anti-allodynic and anti-hyperalgesic effects in animal models of tonic or chronic pain of different origins. Peripheral inflammation and nerve injury may induce spinal plasticity which leads to altered potency and efficacy of nociceptin.