The journal of pain : official journal of the American Pain Society
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Randomized Controlled Trial
Primary sensorimotor cortex is modified by a 6 week graded motor imagery training in chronic CRPS patients: a randomized trial.
Complex regional pain syndrome (CRPS) is a neuropathic pain condition that is difficult to treat. For behavioral interventions, graded motor imagery (GMI) showed relevant effects, but underlying neural substrates in patient groups have not been investigated yet. A previous study investigating differences in the representation of a left/right hand judgment task demonstrated less recruitment of subcortical structures, such as the putamen, in CRPS patients than in healthy controls. ⋯ The design used here is reliable for investigating the functional representation of the hand judgment task in an intervention study. PERSPECTIVE: Twenty chronic CRPS patients underwent a 6 week GMI intervention in a randomized wait-list crossover design. functional MRI was tested pre and post for the hand lateralization task which improved over GMI but not over WAITING. Performance gain was positively related to right parietal functional MRI activation.
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The protease activated receptor (PAR) family is a group of G-protein coupled receptors (GPCRs) activated by proteolytic cleavage of the extracellular domain. PARs are expressed in a variety of cell types with crucial roles in homeostasis, immune responses, inflammation, and pain. PAR3 is the least researched of the four PARs, with little known about its expression and function. ⋯ Our findings suggest a complex role of PAR3 in the physiology and plasticity of nociceptors. PERSPECTIVE: We evaluated the role of PAR3, a G-protein coupled receptor, in nociception by developing a selective peptide agonist. Our findings suggest that PAR3 contributes to nociception in various contexts and plays a role in modulating the activity of other PARs.
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Opioid usage for pain therapy is limited by its undesirable clinical effects, including paradoxical hyperalgesia, also known as opioid-induced hyperalgesia (OIH). However, the mechanisms associated with the development and maintenance of OIH remain unclear. Here, we investigated the effect of serotonin inhibition by the 5-HT3 receptor antagonist, ondansetron (OND), as well as serotonin deprivation via its synthesis inhibitor para-chlorophenylalanine, on mouse OIH models, with particular focus on astrocyte activation. ⋯ Our findings further suggest that serotonergic regulation in the spinal dorsal horn may be a therapeutic target of OIH. PERSPECTIVE: The current study revealed that the descending serotonergic pain-facilitatory system in the spinal dorsal horn is crucial in OIH, and that activation of astrocytes is a secondary phenotype of OIH. Our study offers new therapeutic targets for OIH and may help reduce inappropriate opioid use.
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Review Meta Analysis
A Systematic Review and Meta-Analysis of the Association between Perceived Injustice and Depression.
Perceived injustice is increasingly recognized as a risk factor for problematic recovery, with a growing body of evidence documenting its association with heightened pain, disability, medication use, anger and post-traumatic stress. The aim of this paper was to systematically review and critically appraise the association between perceived injustice and depressive symptomatology across a wide range of medical and mental health populations, including acute and chronic pain samples. A search of published, English language studies in the PubMed, EMBASE, CINAHL, and PsycINFO databases from 1990 to June 2020 was performed. ⋯ PROSPERO: CRD42019143465. PERSPECTIVE: This review demonstrates that in acute injury and chronic pain samples, perceived injustice is associated with depression. These findings could help clinicians in the field of pain and rehabilitation identify who may be at greater risk for a problematic recovery trajectory.
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Randomized Controlled Trial
Optimization of Spinal Manipulative Therapy Protocols: A Factorial Randomized Trial Within a Multiphase Optimization Framework.
Spinal manipulative therapy (SMT) is a common nonpharmacological treatment for low back pain (LBP). Although generally supported by systematic reviews and practice guidelines, clinical trials evaluating SMT have been characterized by small effect sizes. This study adopts a Multiphase Optimization Strategy framework to examine individual components of an SMT delivery protocol using a single-blind trial with the goal of identifying and optimizing a multicomponent SMT protocol. ⋯ PERSPECTIVE: Optimizing the effects of nonpharmacological treatments such as SMT for LBP is challenging due to uncertainty regarding mechanisms and the complexity of multicomponent protocols. This factorial randomized trial examined SMT protocols provided with differing co-interventions with mechanistic and patient-centered outcomes. Patient-centered outcomes were optimized by inclusion of lumbar multifidus strengthening exercises.