Pain
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The ethics of placebo research have been of paramount concern since the discovery of the phenomenon. To address these ethical concerns, Miller and colleagues (PLoS Med 2005 Sep;2(9):e262, 0853-0859) propose an alternate approach to placebo research, called "authorized deception", in which participants are alerted of the use of deception in the research prior to study enrollment and thus knowingly permit its use if they decide to participate. The present study sought to investigate the authorized deception methodology in experimentally induced placebo analgesia. ⋯ The majority of participants who received this form of consent preferred it to the traditional approach in which the participants are not alerted to the presence of deception. These findings suggest that the use of authorized deception is a viable and ethically preferable alternative consent process for laboratory-based studies on placebo analgesia. Further studies are needed to examine the effect of authorized deception in clinical trials and other placebo research within a clinical setting.
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In the present study, intraplantar carrageenan induced increased mechanical allodynia, phosphorylation of PKB/Akt and GluR1 ser 845 (PKA site) as well as GluR1, but not GluR2 movement into neuronal membranes. This change in membrane GluR1/GluR2 ratio is indicative of Ca(2+) permeable AMPA receptor insertion. Pain behavior was reduced and biochemical changes blocked by spinal pretreatment, but not post-treatment, with a tumor necrosis factor (TNF) antagonist, Etanercept (100microg). ⋯ Akt and GluR1 phosphorylation, AMPA receptor trafficking and mechanical allodynia were all TNF dependent. Whether phosphorylation of Akt and of GluR1 are in series or in parallel or upstream of pain behavior remains to be determined. Certainly, TNF-mediated GluR1 trafficking appears to play a major role in inflammatory pain and TNF-mediated effects such as these could represent a path by which glia contribute to neuronal sensitization (spinal LTP) and pathological pain.
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Randomized Controlled Trial Multicenter Study
Contributions of change in clinical status parameters to Patient Global Impression of Change (PGIC) scores among persons with fibromyalgia treated with milnacipran.
Clinical trials on the treatment of pain syndromes have adopted Patient Global Impression of Change (PGIC) as a primary outcome. However, little is known about how change in clinical status influences these ratings. The present study examined relationships between changes in pain, depressed mood, physical functioning, vitality, sleep disturbance, cognitive complaints, and PGIC ratings among 1260 participants with fibromyalgia (FM) who completed one of two trials examining the safety and efficacy of milnacipran. ⋯ Among responders, improvements in pain were significantly associated with better PGIC ratings, along with improvements in vitality, sleep, physical function, and cognitive complaints. These findings underscore the complexity of global ratings in FM patients, and suggest the association between clinical status and PGIC ratings varies as a function of perceived treatment response. Several domains were associated with PGIC ratings, highlighting the need to assess multiple outcomes in clinical trials of treatments for FM.
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Although the verbal numeric scale (VNS) is used frequently at patients' bedsides, it has never been formally validated in children with acute pain. In order to validate this scale, a prospective cohort study was performed in children between 8 and 17years presenting to a pediatric emergency department (ED) with acute pain. Pain was graded using the VNS, the visual analogue scale (VAS), and the verbal rating scale (VRS). ⋯ The VNS minimal clinically significant difference was 1. The VNS had good test-retest reliability with 95% limits of agreement of -0.9 and 1.2. In conclusion, the VNS provides a valid and reliable scale to evaluate acute pain in children aged 8-17years but is not interchangeable with the VAS.