Pain
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Our previous work indicates that the intrathecal administration of neuropeptide Y (NPY) acts at its cognate receptors to reduce behavioral signs of nociception in several models of inflammatory pain, including the formalin test. The present study extends these findings to a rat model of peripheral neuropathic pain, and then evaluates the hypothesis that NPY inhibits inflammation- and nerve injury-induced activation of spinal nociceptive transmission. Here we show that NPY dose-dependently reduced behavioral signs of mechanical and cold hypersensitivity in the spared nerve injury (SNI) model. ⋯ We found that intrathecal NPY reduced both formalin- and SNI-induced Fos expression. NPY inhibition of SNI-induced Fos expression was localized to the sural (uninjured) innervation territory, and could be blocked by intrathecal BIBO3304 and BIIE0246. We conclude that NPY acts at spinal Y1 and Y2 receptors to reduce spinal neuron activity and behavioral signs of inflammatory or neuropathic pain.
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Randomized Controlled Trial Comparative Study
Effectiveness of leech therapy in women with symptomatic arthrosis of the first carpometacarpal joint: a randomized controlled trial.
Leech therapy has been shown to be effective for symptomatic treatment of osteoarthritis of the knee. We aimed to investigate the effectiveness of leech therapy in another type of osteoarthritis, osteoarthritis of the first carpometacarpal joint (thumb saddle joint). Thirty-two women with symptomatic painful osteoarthritis of the first carpometacarpal joint and who scored>40 mm on a 100mm VAS pain scale were randomized to a single treatment with 2-3 locally applied leeches (leech group) or a 30-day course with topical diclofenac twice a day. ⋯ Results were not affected by outcome expectation or consumption of analgetics. A single course of leech therapy is effective in relieving pain, improving disability and QoL for at least 2 months. The potential of leech therapy for treatment of arthritic pain and underlying mechanisms should be further investigated.
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This two-phase study was conducted to identify relevant domains of patient-reported outcomes from the perspective of people who experience chronic pain. In Phase 1, focus groups were conducted to generate a pool of patient outcome-related domains and their components. The results of the focus groups identified 19 aspects of their lives that were significantly impacted by the presence of their symptoms and for which improvements were important criteria they would use in evaluating the effectiveness of any treatment. ⋯ Chronic pain clearly impacts health-related quality of life. The results of the two phases of the study indicate that people with chronic pain consider functioning and well-being as important areas affected by the presence of symptoms and as appropriate targets of treatment. These multiple outcomes should be considered when evaluating the efficacy and effectiveness of chronic pain treatments.
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Idiopathic chronic pain conditions with a mismatch between anatomical abnormalities and symptoms can be categorized as somatoform pain disorder according to the DSM-IV criteria. A dysfunction of pain processing circuits has been suggested as one underlying pathophysiological factor. There is accumulating evidence for a crucial role of affect regulating brain structures such as the medial frontal cortex in this context. ⋯ The average ratings for experimentally induced pain were not significantly different between controls and patients concerning pain intensity and pain unpleasantness. Comparing patients with controls a pain related hypoactive state of the ventromedial prefrontal/orbitofrontal cortex (BA 10/11) and a hyperactive state of the parahippocampal gyrus, amygdala and anterior insula were found in the patient group. Our findings of an altered cerebral processing of experimentally induced pain in patients with somatoform pain disorder support the hypothesis of dysfunctional pain processing, especially in affect regulating regions.