Neuronal basis for pain-like and anxiety-like behaviors in the central nucleus of the amygdala
In this study, we found about 70% of phosphorylated ERK–positive neurons colocalized with PKCδ+ neurons in the formalin-induced pain model in mice. Optogenetic activation of PKCδ+ neurons was sufficient to induce mechanical hyperalgesia without changing anxiety-like behavior in naïve mice. Conversely, chemogenetic inhibition of PKCδ+ neurons significantly reduced the mechanical hyperalgesia in the pain model. By contrast, optogenetic inhibition of SOM+ neurons induced mechanical hyperalgesia in naïve mice and increased phosphorylated ERK–positive neurons mainly in PKCδ+ neurons. Optogenetic activation of SOM+ neu...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Reliability and clinical utility of the chronic pain classification in the 11th Revision of the International Classification of Diseases from a global perspective: results from India, Cuba, and New Zealand
Chronic pain affects 1 in 5 persons and contributes substantially to the global burden of disease. The 11th Revision of the International Classification of Diseases (ICD-11) includes a comprehensive classification of chronic pain. The aim of this ecological implementation field study was to evaluate the classification's interrater reliability and clinical utility in countries with different income levels. The study was conducted in 4 pain clinics in Cuba, India, and New Zealand. Twenty-one clinicians used the ICD-11 to diagnose and code n = 353 patients with chronic pain. Of these, 111 were assessed by 2 clinicians, and Fl...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Diversity of inhibitory and excitatory parvalbumin interneuron circuits in the dorsal horn
Parvalbumin-expressing interneurons (PVINs) in the spinal dorsal horn are found primarily in laminae II inner and III. Inhibitory PVINs play an important role in segregating innocuous tactile input from pain-processing circuits through presynaptic inhibition of myelinated low-threshold mechanoreceptors and postsynaptic inhibition of distinct spinal circuits. By comparison, relatively little is known of the role of excitatory PVINs (ePVINs) in sensory processing. Here, we use neuroanatomical and optogenetic approaches to show that ePVINs comprise a larger proportion of the PVIN population than previously reported and that b...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Beyond pain, distress, and disability: the importance of social outcomes in pain management research and practice
No abstract available (Source: Pain)
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Perspective Source Type: research
Impact of rescue medication in placebo-controlled trials of pharmacotherapy for neuropathic pain and low back pain
This study assessed proportional RM consumption in the placebo and active groups according to results of 42 randomized controlled trials of neuropathic pain (NeP), and 29 trials of low back pain, which were included in 2 systematic reviews and meta-analyses. Trial results were assessed based on effect size, statistical significance, and whether the drug was recommended as first-line treatment by the systematic reviews. In trials indicating effect of the investigational drug, RM consumption was generally higher in the placebo groups than in the active groups. In trials reporting a small or a medium effect size of the invest...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Comprehensive Review Source Type: research
Impact of chronic pain on driving behaviour: a systematic review
Driving is a complex task that requires both the ability to rapidly identify potential hazards and respond appropriately to driving situations to avoid crashing. A great deal of research has sought to increase road safety by focusing on risky behaviours, very few of which have explored the effects of chronic pain (CP) on driving behaviour. This systematic review aimed to assess driving behaviour and motor vehicle crash risk in drivers with CP. Four databases (Embase, PubMed, Scopus, and PsycINFO) were searched using relevant search terms. From 8543 studies, 22 studies met the eligibility criteria for inclusion in this revi...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research
Predictive value of quantitative sensory testing for acute and chronic postsurgical pain after total joint arthroplasty: a systematic review
Quantitative sensory testing (QST) can be useful to identify high-risk patients for the development of chronic postsurgical pain. This systematic review aims to assess if presurgical sensory sensitivity measured using QST is associated with acute and chronic postsurgical pain after total joint arthroplasty. A systematic search was performed in September 2020 in PubMed, EMBASE, Web of Science, and Scopus, using terms related to total joint arthroplasty and QST. Prospective studies were included if they reported an association between presurgical QST and postsurgical pain in adults with osteoarthritis undergoing primary unil...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research
Mitochondrial calcium uniporter deletion prevents painful diabetic neuropathy by restoring mitochondrial morphology and dynamics
Painful diabetic neuropathy (PDN) is an intractable complication affecting 25% of diabetic patients. Painful diabetic neuropathy is characterized by neuropathic pain accompanied by dorsal root ganglion (DRG) nociceptor hyperexcitability, resulting in calcium overload, axonal degeneration, and loss of cutaneous innervation. The molecular pathways underlying these effects are unknown. Using high-throughput and deep-proteome profiling, we found that mitochondrial fission proteins were elevated in DRG neurons from mice with PDN induced by a high-fat diet (HFD). In vivo calcium imaging revealed increased calcium signaling in DR...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Can placebo and nocebo effects generalize within pain modalities and across somatosensory sensations?
Abstract (Source: Pain)
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Distinct aberrations in cerebral pain processing differentiating patients with fibromyalgia from patients with rheumatoid arthritis
The current study used functional magnetic resonance imaging to directly compare disease-relevant cerebral pain processing in well-characterized patient cohorts of fibromyalgia (FM, nociplastic pain) and rheumatoid arthritis (RA, nociceptive pain). Secondary aims were to identify pain-related cerebral alterations related to the severity of clinical symptoms such as pain intensity, depression, and anxiety. Twenty-six patients with FM (without RA-comorbidity) and 31 patients with RA (without FM-comorbidity) underwent functional magnetic resonance imaging while stimulated with subjectively calibrated painful pressures corresp...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Systemic inflammatory markers in neuropathic pain, nerve injury, and recovery
In conclusion, we demonstrate specific dysregulation of systemic cytokine expression in both the active and resolution phases of nerve injury and neuropathic pain. IL-9 represents an interesting candidate associated with resolution of nerve injury and neuropathic pain. (Source: Pain)
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Muscle function, quality, and relative mass are associated with knee pain trajectory over 10.7 years
This study aimed to examine the association of lean mass, muscle strength, and quality with 10.7-year pain trajectory. Nine hundred forty-seven participants from a population-based cohort study were analysed. Dual-energy X-ray absorptiometry was used to assess lean and fat mass. Leg strength, knee extensor strength, and lower-limb muscle quality were measured/calculated. Knee pain was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index pain questionnaire. Radiographic knee osteoarthritis was assessed by X-ray. Three distinct pain trajectories were identified: “Minimal pain” (53%), “Mild pai...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Microglial ablation does not affect opioid-induced hyperalgesia in rodents
Opioids are the frontline analgesics in pain management. However, chronic use of opioid analgesics causes paradoxical pain that contributes to the decrease of their efficacy in pain control and the escalation of dose in long-term management of pain. The underling pathogenic mechanism is not well understood. Microglia have been commonly believed to play a critical role in the expression of opioid-induced hyperalgesia in animal models. We performed microglial ablation experiments using either genetic (CD11b-diphtheria toxin receptor transgenic mouse) or pharmacological (colony-stimulating factor-1 receptor inhibitor PLX5622)...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Oral squamous cell carcinoma–released brain-derived neurotrophic factor contributes to oral cancer pain by peripheral tropomyosin receptor kinase B activation
Oral cancer pain is debilitating and understanding mechanisms for it is critical to develop novel treatment strategies treatment strategies. Brain-derived neurotrophic factor (BDNF) signaling is elevated in oral tumor biopsies and is involved with tumor progression. Whether BDNF signaling in oral tumors contributes to cancer-induced pain is not known. The current study evaluates a novel peripheral role of BDNF-tropomyosin receptor kinase B (TrkB) signaling in oral cancer pain. Using human oral squamous cell carcinoma (OSCC) cells and an orthotopic mouse tongue cancer pain model, we found that BDNF levels were upregulated i...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
Whiplash injuries associated with experienced pain and disability can be visualized with [11C]-D-deprenyl positron emission tomography and computed tomography
Knowledge of etiological mechanisms underlying whiplash-associated disorders is incomplete. Localisation and quantification of peripheral musculoskeletal injury and inflammation in whiplash-associated disorders would facilitate diagnosis, strengthen patients' subjective pain reports, and aid clinical decisions, all of which could lead to improved treatment. In this longitudinal observational study, we evaluated combined [11C]-D-deprenyl positron emission tomography and computed tomography after acute whiplash injury and at 6-month follow-up. Sixteen adult patients (mean age 33 years) with whiplash injury grade II were recr...
Source: Pain - February 14, 2022 Category: Anesthesiology Tags: Research Paper Source Type: research
