Pain

Little is known about the effectiveness of placebo interventions in patients with non-specific low back pain (LBP). This systematic review assessed the magnitude of the effects of placebo interventions as compared to no intervention in randomized controlled trials(RCTs) including patients with LBP. Embase, Medline(Ovid) and Cochrane CENTRAL databases were searched from inception to December 5th, 2019. RCTs comparing placebo intervention versus no intervention in adult patients with non-specific LBP were included...

Lamina I of the dorsal horn, together with its main output pathway, lamina I projection neurons, have long been implicated in the processing of nociceptive stimuli, as well as the development of chronic pain conditions. However, the study of lamina I projection neurons is hampered by technical challenges, including the low throughput and selection biases of traditional electrophysiological techniques. Here we report on a technique which employs anatomical labelling strategies and in vivo imaging to simultaneously study a network of lamina I projection neurons in response to electrical and natural stimuli...

Deprescribing opioids has been identified as an intervention to mitigate opioid harm, however, it is often challenging to implement interventions and communicate deprescribing decisions to consumers. The development of opioid deprescribing guidelines may provide guidance and support on when and how to reduce or cease opioids in routine care. This study aimed to explore the perspectives of opioid consumers on opioid deprescribing and determine factors to be considered in the development of opioid deprescribing guidelines...

Tricyclic antidepressants that inhibit serotonin and noradrenaline reuptake, such as amitriptyline, are among the first-line treatments for neuropathic pain, which is caused by a lesion or disease affecting the somatosensory nervous system. These treatments are, however, partially efficient to alleviate neuropathic pain symptoms and better treatments are still highly required. Interactions between neurons and glial cells participate in neuropathic pain processes, and, importantly, connexins - transmembrane proteins involved in cell-cell communication - contribute to these interactions...

No abstract text is available yet for this article.

During the past few years, the research of chronic neuropathic pain has focused on neuroinflammation within the central nervous system and its impact on pain chronicity. As part of the ERA-Net NEURON consortium we aimed to identify immune cell patterns in cerebrospinal fluid (CSF) of patients with herpes zoster neuralgia (HZ) and polyneuropathy (PNP), which may contribute to pain chronicity in these neuropathic pain conditions.CSF of 41 patients (10 HZ, 31 PNP) was analyzed by flow cytometry identifying lymphocyte subsets: CD4+- (T-helper-cells), CD8+- (cytotoxic T-cells), CD19+- (B-cells), and CD56+- (natural killer; NK) cells...

Compared to racism and sexism, classism in pain assessment and management practices (PAMP) has been less investigated and its mediating mechanisms are still unknown. Drawing upon a social psychological model of dehumanization, this research aimed to test: (1) the effect of patient socioeconomic status (SES; a proxy of social class) on PAMP and (2) whether patient dehumanization and perceived life hardship mediated these effects. Two online experimental studies were conducted, in which patient SES was manipulated (Low vs...

No abstract text is available yet for this article.

The German Research Network on Neuropathic Pain (DFNS) quantitative sensory testing (QST) method for sensory phenotyping is used to stratify patients by mechanism associated sensory phenotype, theorised to be predictive of intervention efficacy. We hypothesised that change in pain and sensory dysfunction would relate to change in sensory phenotype. We investigated the responsiveness of sensory phenotype to surgery in patients with an entrapment neuropathy.With ethical approval and consent, this observational study recruited patients with neurophysiologically confirmed carpal tunnel syndrome...

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No abstract text is available yet for this article.

This narrative review represents an output from the International Association for the Study of Pain's global task force on the use of cannabis, cannabinoids, and cannabis-based medicines (CBM) for pain management, informed by our companion systematic review and meta-analysis of preclinical studies in this area. Our aims in this review are: 1) to describe the value of studying cannabinoids and endogenous cannabinoid (endocannabinoid) system modulators in preclinical/animal models of pain; 2) to discuss both pain-related efficacy and additional pain-relevant effects (adverse and beneficial) of cannabinoids and endocannabinoid system modulators as they pertain to animal models of pathological or injury-related persistent pain; and 3) to identify important directions for future research...

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We report a systematic review and meta-analysis of studies which assessed the antinociceptive efficacy of cannabinoids, cannabis-based medicines, and endocannabinoid system modulators on pain-associated behavioural outcomes in animal models of pathological or injury-related persistent pain. In April 2019, we systematically searched 3 online databases and used crowd science and machine learning to identify studies for inclusion. We calculated a standardised mean difference (SMD) effect size for each comparison and performed a random effects meta-analysis...

Damage to thinly-myelinated and unmyelinated nerve fibers causes small fiber pathology, which is increasingly found in pain syndromes such as small fiber neuropathy (SFN) and fibromyalgia syndrome (FMS). The peripheral nerve endings of the small nerve fibers terminate within the epidermis, where they are surrounded by keratinocytes that may act as primary nociceptive transducers.We performed RNA sequencing of keratinocytes obtained from patients with SFN, FMS, and healthy controls. We found 141 deregulated protein coding genes between SFN patients and healthy controls and no differentially expressed genes between FMS patients and healthy controls...

The analgesic efficacy and safety of two Phase 2b studies of EMA401 (a highly selective angiotensin II type 2 receptor antagonist), in patients with postherpetic neuralgia (PHN; EMPHENE) and painful diabetic neuropathy (EMPADINE) were reported. These were multicentre, randomised, double-blind treatment studies conducted in participants with PHN or type I/II diabetes mellitus with painful distal symmetrical sensorimotor neuropathy. Participants were randomised 1:1:1 to either placebo, EMA401 25 mg, or 100 mg twice daily (b...

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Appropriate outcome measures and high-quality intervention trials are critical to advancing care for children with chronic pain. Our aim was to update a core outcome set for pediatric chronic pain interventions. The first phase involved collecting providers', patients', and parents' perspectives about treatment of pediatric chronic pain to understand clinically meaningful outcomes to be routinely measured. The second phase was to reach consensus of mandatory and optional outcome domains following the OMERACT framework...

Migraine is highly prevalent and is the sixth leading cause worldwide for years lost to disability. Therapeutic options specifically targeting migraine are limited, and delta opioid receptor (DOP) agonists were recently identified as a promising pharmacotherapy. The mechanisms by which DOPs regulate migraine are currently unclear. Calcitonin gene- related peptide (CGRP) has been identified as an endogenous migraine trigger and plays a critical role in migraine initiation and susceptibility. The aim of this study was to determine the behavioral effects of DOP agonists on the development of chronic migraine-associated pain, and to investigate DOP co-expression with CGRP and CGRP receptor in the trigeminal system...

It is commonly believed that blinding to treatment assignment is necessary for placebos to have an effect. However, placebos administered without concealment (i.e., open-label placebos [OLP]) have recently been shown to be effective in some conditions. This study had two objectives: first, to determine whether OLP treatment is superior to no-pill control (NPC) in irritable bowel syndrome (IBS); and second, to compare the efficacy of OLP against double-blind placebo (DBP). In a six-week, three-arm, randomized clinical trial, participants were randomized in equal proportions to three arms: OLP, DBP or NPC...