The journal of pain : official journal of the American Pain Society
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Although pain is a commonly experienced and observed affective state, it is frequently misinterpreted, which leads to inadequate caregiving. Studies show the ability at estimating pain in others (estimation bias) and detecting its subtle variations (sensitivity) could emerge from independent mechanisms. While estimation bias is modulated by variables such as empathy level, pain catastrophizing tendency, and overexposure to pain, sensitivity remains unimpacted. ⋯ Together, these results provide evidence for a perceptual contribution in pain inferencing that is independent of other psychosocial variables and its link to observers' expectations. PERSPECTIVE: This article reinforces the contribution of perceptual mechanisms in pain assessment. Moreover, strategies aimed to improve the reliability of individuals' expectations regarding the appearance of facial expressions of pain could potentially be developed, and contribute to decrease inaccuracies found in pain assessment and the confusion between pain and other affective states.
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We conducted a meta-epidemiological study on all non-specific low back pain (NSLBP) trial registrations on the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov. We aimed to 1) assess the uptake of the core outcome set (COS) for NSLBP in clinical trials; 2) assess the uptake of the core outcome measurement set for NSLBP in clinical trials; and 3) determine whether specific study characteristics are associated with the COS uptake. After applying the relevant filters for the condition, study type, and phase of the trial, 240 registry entries were included in this study. ⋯ We evaluated whether trial registrations are using this set of outcomes when testing interventions for low back pain. Full uptake was found only in 21% of the sample, and this is not increasing over time. Researchers should use the COS to ensure that trials measure relevant outcomes consistently.
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Lateral epicondylalgia (LE), commonly referred to as tennis elbow, is a musculoskeletal condition characterized by pain and sensorimotor dysfunction. In some individuals with chronic unilateral LE, sensorimotor symptoms develop on the unaffected side despite no evidence of tissue damage. Altered interhemispheric inhibition (IHI) is one mechanism that could underpin this phenomenon. ⋯ Further studies are required to determine the mechanisms that underpin the development of bilateral sensorimotor symptoms in unilateral LE. PERSPECTIVE: IHI is unaltered from the affected M1 (corresponding to the painful muscle) to unaffected M1 in individuals with LE compared to healthy controls. The absence of bilateral sensorimotor dysfunction and low pain severity in this cohort of individuals with LE may explain this finding.
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The 3-item pain intensity (P), interference with the enjoyment of life (E), and interference with general activity (G), or PEG, has become one of the most widely used measures of pain severity and interference. The minimally important differences (MID) and responsiveness of the PEG are essential metrics for solidifying its role in research and clinical care. The current study aims to establish the MID and responsiveness of the PEG by synthesizing data from 1,710 participants across 6 controlled trials. ⋯ Our synthesis indicates that 1 point is a reasonable MID estimate on these 0- to 10-point pain scales, with 2 points being an upper bound. PERSPECTIVE: This article synthesizes data from 6 clinical trials to establish the minimally important difference (MID) and responsiveness of the 3-item PEG pain scale. The PEG demonstrated good responsiveness, and 1 to 2 points proved to be reasonable estimates for the lower and upper bounds of the MID.
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Offset analgesia (OA) is observed when pain relief is disproportional to the reduction of noxious input and is based on temporal contrast enhancement (TCE). This phenomenon is believed to reflect the function of the inhibitory pain modulatory system. However, the mechanisms contributing to this phenomenon remain poorly understood, with previous research focusing primarily on painful stimuli and not generalizing to nonpainful stimuli. ⋯ More research is needed to confirm a peripheral influence. PERSPECTIVE: This psychophysical study presents the observation of temporal contrast enhancement during NH, NC, and innocuous cold stimuli but not during stimulation with innocuous warm temperatures in healthy volunteers. A better understanding of endogenous pain modulation mechanisms might be helpful in explaining the underlying aspects of pain disorders.