The journal of pain : official journal of the American Pain Society
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Initial content validation and roadmap for a new patient-reported outcome measure of pain intensity.
Measures of pain intensity (eg, numeric rating scales [NRS]) are widely used in clinical research and practice. While these measures have evidence for validity and reliability, poor standardization of instructions, and response options limits precision of pain assessment, allows for inconsistency in interpretation, and presents a challenge for comparison and aggregation of study results. Despite these pitfalls, the 0 to 10 NRS remains the most commonly used primary outcome measure in clinical trials of pain treatments and is the core measure recommended by regulatory agencies. ⋯ This article summarizes interview findings, describes how patient input and FDA feedback informed preliminary candidate measures, and provides an overview of the FDA qualification process. PERSPECTIVE: Concept elicitation interviews informed the development of content-valid candidate measures of acute and chronic pain intensity for planned use in clinical trials of pain treatments, and comprise the initial stage in FDA clinical outcome assessment qualification. Measures will subsequently be evaluated through cognitive interviews and a series of psychometric studies.
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Chronic triptan exposure in rodents recapitulates medication overuse headache (MOH), causing cephalic pain sensitization and trigeminal ganglion overexpression of pronociceptive proteins including CGRP. Because of these transcriptional derangements, as well as the emerging role of epigenetics in chronic pain, in the present study, we evaluated the effects of the histone deacetylase inhibitors (HDACis) panobinostat and givinostat, in rats chronically exposed to eletriptan for 1 month. Both panobinostat and givinostat counteracted overexpression of genes coding for CGRP and its receptor subunit RAMP1, having no effects on CLR and RCP receptor subunits in the trigeminal ganglion (TG) of eletriptan-exposed rats. ⋯ The drugs, however, increased luciferase expression driven by CGRP promoter in cultured cells. Our findings provide evidence for a key role of HDACs and epigenetics in MOH pathogenesis, highlighting the therapeutic potential of HDAC inhibition in the prevention of migraine chronification. PERSPECTIVE: The present study highlights a key epigenetic role of HDAC in the rodent model of medication overuse headache, furthering our understanding of the molecular mechanisms responsible for pronociceptive sensitization during headache chronification.
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To calibrate or not to calibrate? This question is raised by almost everyone designing an experimental pain study with supra-threshold stimulation. The dilemma is whether to individualize stimulus intensity to the pain threshold / supra-threshold pain level of each participant or whether to provide the noxious stimulus at a fixed intensity so that everyone receives the identical input. Each approach has unique pros and cons which need to be considered to i) accurately design an experiment, ii) enhance statistical inference in the given data and, iii) reduce bias and the influence of confounding factors in the individual study e.g., body composition, differences in energy absorption and previous experience. ⋯ PERSPECTIVE: To calibrate pain or not? This dilemma is related to almost every experimental pain research. The decision is a trade-off between statistical power and greater control of stimulus encoding. The article decomposes both approaches and presents the pros and cons of either approach supported by data and simulation experiment.
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Black communities are disproportionally affected by Chronic Musculoskeletal Pain (CMP), but little is known about the psychological predictors of CMP outcomes and their contextual determinants among Black individuals. To address this gap, we conducted a narrative review of extant literature to (1) report the major conceptual models mentioned in prior work explaining the link between contextual determinants and psychological responses to pain among Black individuals with CMP; and (2) describe psychological factors related to CMP outcomes in this population that are highlighted in the literature. ⋯ PERSPECTIVE: This narrative review illustrates conceptual models explaining the link between contextual determinants and psychological responses to pain among Black individuals with chronic musculoskeletal pain. We discuss 3 relevant conceptual models - socioecological, cumulative stress, biopsychosocial -, and 4 psychological factors: disproportionate burden of mental health, distinct coping strategies, perceived injustice/discrimination, preferences/expectations.
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Somatic symptom disturbance is among the strongest predictors of painful temporomandibular disorder (TMD). Related psychological constructs, such as anxiety and depression, respond therapeutically to omega-3 polyunsaturated fatty acids (PUFAs) in clinical trials. This cross-sectional study investigated associations between the omega-6/omega-3 PUFA ratio and somatic symptom disturbance and depressive symptoms in a community-based sample of 501 adults and determined whether these associations differed between adults with and without TMD or irritable bowel syndrome (IBS). ⋯ PERSPECTIVE: In people with TMD or IBS, a high n-6/n-3 PUFA ratio was positively associated with somatic symptom disturbance and depressive symptoms. Both measures of psychological distress were elevated in people with painful TMD and IBS. Future randomized clinical trials will determine whether lowering the n-6/n-3 ratio is therapeutic for pain.