Activation of cannabinoid receptors by the pentacyclic triterpene α,β-amyrin inhibits inflammatory and neuropathic persistent pain in mice: erratum
No abstract available (Source: Pain)
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Erratum Source Type: research

Kappa opioid receptor blockade in the nucleus accumbens shell prevents sex-dependent alcohol deprivation effect induced by inflammatory pain
Pain-induced negative affect reduces life quality of patients by increasing psychiatric comorbidities, including alcohol use disorders (AUDs). Indeed, clinical data suggest pain as a risk factor to suffer AUDs, predicting relapse drinking in abstinent patients. Here, we analyse the impact of pain on alcohol relapse and the role of kappa opioid receptor (KOR) activation in mediating these pain-induced effects because KORs play an important role in pain-driven negative affect and AUD. Female and male Sprague-Dawley rats underwent 2 alcohol intermittent access periods separated by a forced abstinence period. The complete Freu...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Impact of changes in opioid funding and clinical policies on rapid tapering of opioids in Ontario, Canada
Reports have emerged of abrupt tapering among recipients of long-term prescription opioids to conform new prescribing guidelines. We conducted a population-based, repeated cross-sectional time-series study among very high-dose (≥200 MME) opioid recipients in Ontario, Canada, to examine changes in the monthly prevalence of rapid tapering from 2014 to 2018, defined as recipients experiencing either a ≥50% reduction in daily doses or abrupt discontinuation sustained for 30 days. Interventional autoregressive integrated moving average models were used to test for significant changes following key guidelines and drug poli...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Pain is common after sexual assault and posttraumatic arousal/reactivity symptoms mediate the development of new or worsening persistent pain
Clinically significant new or worsening pain (CSNWP) is a common, yet often overlooked, sequelae of sexual assault. Little is known regarding factors influencing the development of CSNWP in sexual assault survivors. The current study used data from a recently completed prospective study to evaluate whether posttraumatic alterations in arousal and reactivity in the early aftermath of sexual assault influence the transition from acute to clinically significant new or worsening persistent pain. Women ≥ 18 years of age (n = 706) presenting for emergency care after sexual assault to 13 emergency care sites were enrolled in t...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Sympathectomy decreases pain behaviors and nerve regeneration by downregulating monocyte chemokine CCL2 in dorsal root ganglia in the rat tibial nerve crush model
In this study, we examined the effect of a localized “microsympathectomy,” ie, cutting the gray rami containing sympathetic postganglionic axons where they enter the L4 and L5 spinal nerves, which is more analogous to clinically used sympathetic blockade compared with chemical or surgical sympathectomy. We also examined manipulations of CCL2 (monocyte chemoattractant protein 1), a key player in both regeneration and pain. We used rat tibial nerve crush as a neuropathic pain model in which peripheral nerve regeneration can occur successfully. CCL2 in the sensory ganglia was increased by tibial nerve crush and re...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

From acute to long-term alterations in pain processing and modulation after spinal cord injury: mechanisms related to chronification of central neuropathic pain
A severe and debilitating consequence of a spinal cord injury (SCI) is central neuropathic pain (CNP). Our aim was to investigate the processes leading to CNP emergence and chronification by analyzing causal relationship over time between spinothalamic function, pain excitability, and pain inhibition after SCI. This longitudinal follow-up study included 53 patients with acute SCI and 20 healthy controls. Spinothalamic, pain excitability, and intrasegmental and extrasegmental pain inhibition indices were repeatedly evaluated at 1.5, 3, and 6 months post-SCI. Between- and within-group analyses were conducted among those pati...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Opioid prescribing in the U.S. Military Health System, 2014 to 2018: fewer prescriptions, fewer pills, and shorter treatment duration
Prescription opioids remain an important driver of the opioid crisis in the United States. The purpose of this study was to examine recent changes in opioid prescribing patterns in the Military Health System (MHS) which is a nationwide health system service active duty military personnel and civilian beneficiaries. All patients prescribed opioid analgesics by MHS providers and filled at MHS pharmacies between 2014 and 2018 were identified. Prescriptions were converted to oral morphine equivalents (OMEs) and categorized based on prescribing specialty and formulation. Total opioid prescription counts and opioid prescription ...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Olorinab (APD371), a peripherally acting, highly selective, full agonist of the cannabinoid receptor 2, reduces colitis-induced acute and chronic visceral hypersensitivity in rodents
Abdominal pain is a key symptom of inflammatory bowel disease and irritable bowel syndrome, for which there are inadequate therapeutic options. We tested whether olorinab—a highly selective, full agonist of the cannabinoid receptor 2 (CB2)—reduced visceral hypersensitivity in models of colitis and chronic visceral hypersensitivity (CVH). In rodents, colitis was induced by intrarectal administration of nitrobenzene sulfonic acid derivatives. Control or colitis animals were administered vehicle or olorinab (3 or 30 mg/kg) twice daily by oral gavage for 5 days, starting 1 day before colitis induction. Chronic visc...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Pain response to cannabidiol in induced acute nociceptive pain, allodynia, and hyperalgesia by using a model mimicking acute pain in healthy adults in a randomized trial (CANAB I)
This study assessed the effect of CBD on acute pain, hyperalgesia, and allodynia compared with placebo. Twenty healthy volunteers were included in this randomized, placebo-controlled, double-blinded, crossover study assessing pain intensities (using numeric rating scale), secondary hyperalgesia (von Frey filament), and allodynia (dry cotton swab) in a well-established acute pain model with intradermal electrical stimulation. The authors compared the effect of 800-mg orally administered CBD on pain compared with placebo. They further examined the effect on hyperalgesia and allodynia. Cannabidiol whole blood levels were also...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Central amygdala inflammation drives pain hypersensitivity and attenuates morphine analgesia in experimental autoimmune encephalomyelitis
Chronic pain is a highly prevalent symptom associated with the autoimmune disorder multiple sclerosis (MS). The central nucleus of the amygdala plays a critical role in pain processing and modulation. Neuropathic pain alters nociceptive signaling in the central amygdala, contributing to pain chronicity and opioid tolerance. Here, we demonstrate that activated microglia within the central amygdala disrupt nociceptive sensory processing and contribute to pain hypersensitivity in experimental autoimmune encephalomyelitis (EAE), the most frequently used animal model of MS. Male and female mice with EAE exhibited differences in...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Reciprocal interaction between depression and pain: results from a comprehensive bidirectional Mendelian randomization study and functional annotation analysis
To understand a putative causal link for depression and pain, we retrieved summary statistics from genome-wide association studies conducted for pain at 7 different body sites (N = 151,922-226,683) and major depression disorder (MDD, Ncase/control = 246,363/561,190). We conducted a bidirectional Mendelian randomization analysis using distinct genome-wide association studies-identified single nucleotide polymorphisms for each trait as instrumental variables and performed several sensitivity analyses to verify Mendelian randomization assumptions. We also conducted functional annotation analysis using 396 tissue-specific anno...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Relationship between gait complexity and pain attention in chronic low back pain
Clinical models of chronic low back pain (cLBP) highlight the role of excessive attention to pain and kinesiophobia on the origin of disability. At the motor control level, various mechanisms are involved in the impairments observed in patients with cLBP. We aimed to assess the role of maladaptative attentional behaviors by using a complex systems approach and a visual display as a distraction during walking. Sixteen patients with cLBP with no previous surgery or significant leg pain and 16 healthy matched controls were included. Patients walked on a treadmill at preferred walking speed with and without distraction. Stride...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Association of endocannabinoids with pain in endometriosis
Endocannabinoid (eCB) levels fluctuate in inflammatory conditions and as such may take part in endometriosis-associated pain or even in endometriosis pathogenesis. In this case–control (23 cases and 19 controls) study, targeted lipids were measured in the serum and peritoneal fluid collected during laparoscopy. Endometriosis was confirmed histologically. Dysmenorrhea, abdominal pain, and dyspareunia were assessed using the Numeric Rating Scale for pain. Steroids, eCBs, and related lipids were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Tumor necrosis factor alpha, IL-8, PAPP-A, PP14, RANT...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Beta 2-adrenergic receptor mediates noradrenergic action to induce cyclic adenosine monophosphate response element-binding protein phosphorylation in satellite glial cells of dorsal root ganglia to regulate visceral hypersensitivity
This study combined in vitro and in vivo approaches to identify the cell types of DRG that received NE action and examined cell type–specific expression of adrenergic receptors (ARs) in DRG. Using DRG explants, we identified that NE acted on satellite glial cells (SGCs) to induce the phosphorylation of cAMP response element-binding protein (CREB). Using primarily cultured SGCs, we identified that beta (β)2-adrenergic receptor but not alpha (α)adrenergic receptor nor other βAR isoforms mediated NE-induced CREB phosphorylation and CRE-promoted luciferase transcriptional activity. Using fluorescence in s...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Achieving reliable pain change scores for individuals in the postoperative phase: carefully choose sampling density, test length, and administration mode
In this study, we investigate the ability of 2 instruments from the Patient-Reported Outcomes Measurement Information System, pain interference (6 items) and pain behavior (7 items), to reliably detect individual changes in pain during the postsurgical period of a hernia repair in 98 patients who answered daily diaries over almost 3 weeks after surgery. To identify the most efficient strategy for obtaining sufficiently reliable estimates of change (reliability>0.9), the number of measurement occasions over the study period (sampling density), the number of items (test length), and the mode of administration (ie, static ...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Presurgical distress about bodily sensations predicts chronic postsurgical pain intensity and disability 6 months after cardiothoracic surgery
Chronic postsurgical pain (CPSP) and disability after cardiothoracic surgery are highly prevalent and difficult to treat. Researchers have explored a variety of presurgical risk factors for CPSP and disability after cardiothoracic surgery, including one study that examined distress from bodily sensations. The current prospective, longitudinal study sought to extend previous research by investigating presurgical distress about bodily sensations as a risk factor for CPSP and disability after cardiothoracic surgery while controlling for several other potential psychosocial predictors. Participants included 543 adults undergoi...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Antagonism of the mu-delta opioid receptor heterodimer enhances opioid antinociception by activating Src and calcium/calmodulin-dependent protein kinase II signaling
The opioid receptors are important regulators of pain, reward, and addiction. Limited evidence suggests the mu and delta opioid receptors form a heterodimer (MDOR), which may act as a negative feedback brake on opioid-induced analgesia. However, evidence for the MDOR in vivo is indirect and limited, and there are few selective tools available. We recently published the first MDOR-selective antagonist, D24M, allowing us to test the role of the MDOR in mice. We thus cotreated CD-1 mice with D24M and opioids in tail flick, paw incision, and chemotherapy-induced peripheral neuropathy pain models. D24M treatment enhanced oxymor...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

When experience is not enough: learning-based cognitive pain modulation with or without instructions
The effects of expectations on pain perception are often studied using large differences in pain probabilities between experimental conditions, although they may be far more subtle in clinical contexts and, therefore, more difficult to detect. The current study aimed to investigate at which point subtle differences in pain probabilities can be detected and lead to differentiable expectations and perceptions. Furthermore, we investigated whether instructions can aid learning from experience and enhance subsequent pain modulatory effects. During a predictive learning task, participants were presented with 5 different cues, f...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Central pain modulatory mechanisms of attentional analgesia are preserved in fibromyalgia
Fibromyalgia is a prevalent pain condition that is associated with cognitive impairments including in attention, memory, and executive processing. It has been proposed that fibromyalgia may be caused by altered central pain processing characterised by a loss of endogenous pain modulation. We tested whether attentional analgesia, where cognitive engagement diminishes pain percept, was attenuated in patients with fibromyalgia (n = 20) compared with matched healthy controls (n = 20). An individually calibrated, attentional analgesia paradigm with a 2 × 2 factorial design was used with brain and brainstem-focussed functi...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Effects of combined chemotherapy and anti-programmed cell death protein 1 treatment on peripheral neuropathy and neuroinflammation in mice
In this study, we show that C57BL/6 mice treated with the chemotherapeutic drug paclitaxel or cotherapy (paclitaxel and anti–PD-1), but not with anti–PD-1 alone, exhibited increased mechanical sensitivity of the hind paw. Both chemotherapy and immunotherapy caused a reduction in neurite outgrowth of dorsal root ganglion (DRG) explants derived from treated mice, whereas only paclitaxel reduced the neurite outgrowth after direct in vitro treatment. Mice treated with anti–PD-1 or cotherapy exhibited distinct T-cell changes in the lymph nodes and increased T-cell infiltration into the DRG. Mice treated with p...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Noninvasive bladder testing of adolescent females to assess visceral hypersensitivity
Excess pain after visceral provocation has been suggested as a marker for chronic pelvic pain risk in women. However, few noninvasive tests have been validated that could be performed readily on youth in early risk windows. Therefore, we evaluated the validity and reliability of a noninvasive bladder pain test in 124 healthy premenarchal females (median age 11, [interquartile range 11-12]), as previously studied in adult women. We explored whether psychosocial, sensory factors, and quantitative sensory test results were associated with provoked bladder pain and assessed the relation of bladder pain with abdominal pain hist...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Efficacy and safety of single-dose DFN-15 for treatment of acute postsurgical dental pain: a randomized, double-blind, placebo-controlled study
The analgesic efficacy and safety of DFN-15, a new oral liquid formulation of celecoxib with more rapid absorption than the capsule, were evaluated in the treatment of acute pain in adult patients after dental surgery. In this randomized, double-blind, placebo-controlled, dose-ranging study, 120 otherwise healthy adults who underwent the extraction of bilateral impacted mandibular third molar teeth and experienced moderate to severe pain postsurgery were randomly assigned, in a 1:1:1:1 ratio, to receive one dose of either placebo or DFN-15 at 3 doses: 62.5, 125, and 250 mg. Participants were evaluated at prespecified time ...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Patient outcomes after opioid dose reduction among patients with chronic opioid therapy
We examined whether rapid dose reduction after high-dose chronic opioid therapy (COT) associates with suicide, overdose, or other opioid-related adverse events. This retrospective cohort study included Oregon Medicaid recipients with high-dose COT. Claims were linked with prescription data from the prescription drug monitoring program and death data from vital statistics, 2014 to 2017. Participants were placed into 4 mutually exclusive dose trajectory groups after the high-dose COT period, and Cox proportional hazard models were used to examine the effect of dose changes on patient outcomes in the following year. Of the 14...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Clinical and economic burden of prescribing tramadol and other opioids for patients with osteoarthritis in a commercially insured population in the United States
In 2019, the American College of Rheumatology conditionally recommended tramadol and conditionally recommended against nontramadol opioids for patients with hip and knee osteoarthritis. Although tramadol is known to be less prone to opioid use disorders, little is known about the differing magnitude of negative clinical outcomes, health care resource utilization, and costs of tramadol relative to nontramadol opioids. Administrative claims records for commercially insured patients with osteoarthritis who were prescribed opioids were used to compare clinical and cost outcomes during a 3-year follow-up period by conducting a ...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Membrane potential instabilities in sensory neurons: mechanisms and pathophysiological relevance
Peripheral sensory neurons transduce physicochemical stimuli affecting somatic tissues into the firing of action potentials that are conveyed to the central nervous system. This results in conscious perception, adaptation, and survival, but alterations of the firing patterns can result in pain and hypersensitivity conditions. Thus, understanding the molecular mechanisms underlying action potential firing in peripheral sensory neurons is essential in sensory biology and pathophysiology. Over the past 30 years, it has been consistently reported that these cells can display membrane potential instabilities (MPIs), in the form...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Narrative Review Source Type: research

Role of population-based cohorts in understanding the emergence and progression of musculoskeletal pain
No abstract available (Source: Pain)
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Perspective Source Type: research

Evaluating the stability of opioid efficacy over 12 months in patients with chronic noncancer pain who initially demonstrate benefit from extended release oxycodone or hydrocodone: harmonization of Food and Drug Administration patient-level drug safety study data
Abstract: Opioids relieve acute pain, but there is little evidence to support the stability of the benefit over long-term treatment of chronic noncancer pain. Previous systematic reviews consider only group level published data which did not provide adequate detail. Our goal was to use patient-level data to explore the stability of pain, opioid dose, and either physical function or pain interference in patients treated for 12 months with abuse deterrent formulations of oxycodone and hydrocodone. All available studies in the Food and Drug Administration Document Archiving, Reporting, and Regulatory Tracking System were ...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

Pragmatic trials of pain therapies: a systematic review of methods
Pragmatic randomised clinical trials aim to directly inform clinical or health policy decision making. Here, we systematically review methods and design of pragmatic trials of pain therapies to examine methods, identify common challenges, and areas for improvement. Seven databases were searched for pragmatic randomised controlled clinical trials that assessed pain treatment in a clinical population of adults reporting pain. All screening steps and data extractions were performed twice. Data were synthesised descriptively, and correlation analyses between prespecified trial features and PRECIS-2 (PRagmatic–Explanatory...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

Risk factors for persistent pain after breast and thoracic surgeries: a systematic literature review and meta-analysis
The objective of this work was to systematically review and meta-analyze the literature on risk factors of PPSP after breast and thoracic surgeries. A systematic literature search using Ovid Medline, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature, Embase, PsycINFO, and Scopus databases was conducted. Study screening with inclusion and exclusion criteria, data extraction, and risk of bias assessment was performed independently by 2 authors. The data for each surgical group were analyzed separately and meta-analyzed where possible. The literature search yielded 5584 a...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

Short-term impact of combining pain neuroscience education with exercise for chronic musculoskeletal pain: a systematic review and meta-analysis
Exercise and pain neuroscience education (PNE) have both been used as standalone treatments for chronic musculoskeletal pain. The evidence supporting PNE as an adjunct to exercise therapy is growing but remains unclear. The aim of this systematic review and meta-analysis was to evaluate the effect of combining PNE and exercise for patients with chronic musculoskeletal pain, when compared with exercise alone. A systematic search of electronic databases was conducted from inception to November 6, 2020. A quality effects model was used to meta-analyze outcomes where possible. Five high-quality randomized controlled studies (n...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

Efficacy and safety of pharmacological, physical, and psychological interventions for the management of chronic pain in children: a WHO systematic review and meta-analysis
Chronic pain in childhood is an international public health problem. We conducted a systematic review and meta-analysis to provide a summary of the published evidence of pharmacological, physical, and psychological therapies for children with chronic pain conditions. We searched CENTRAL, MEDLINE, EMBASE, and PsycINFO from inception to April 2020; clinical trial registries; and other sources for randomised controlled trials or comparative observational trials. We extracted critical outcomes of pain intensity, quality of life, physical functioning, role functioning, emotional functioning, sleep, and adverse events. We assess...
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

Prescribing and deprescribing opioids
No abstract available (Source: Pain)
Source: Pain - December 27, 2021 Category: Anesthesiology Tags: Commentary Source Type: research

Alternate mechanisms of SARS-CoV-2–induced analgesia and additional pathological significance of SARS-CoV-2 spike protein interaction with vascular endothelial growth factor-A/neuropilin-1 receptor signaling
No abstract available (Source: Pain)
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Correspondence Source Type: research

Internet-delivered cognitive behavioral therapy for youth with functional abdominal pain: a randomized clinical trial testing differential efficacy by patient subgroup
Inconsistent results of psychological treatments for pediatric functional abdominal pain (FAP) may be due to heterogeneity of patients' pain-related psychological characteristics. This randomized controlled trial tested whether statistically derived patient subgroups (high pain dysfunctional [HPD], high pain adaptive [HPA], and low pain adaptive [LPA]) moderated response to cognitive behavior therapy (CBT) for adolescents with FAP and their parents (n = 278 dyads; patients were 66% female, mean [SD] age was 14.62 [1.88] years, and parents were 95% female). Randomization to Internet-delivered CBT vs Internet-delivered pain ...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Investigating the specificity of the neurologic pain signature against breathlessness and finger opposition
Brain biomarkers of pain, including pain-predictive “signatures” based on brain activity, can provide measures of neurophysiological processes and potential targets for interventions. A central issue relates to the specificity of such measures, and understanding their current limits will both advance their development and explore potentially generalizable properties of pain to other states. Here, we used 2 data sets to test the neurologic pain signature (NPS), an established pain neuromarker. In study 1, brain activity was measured using high-field functional magnetic resonance imaging (7T fMRI, N = 40) during ...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Dorsal root ganglion stimulation of injured sensory neurons in rats rapidly eliminates their spontaneous activity and relieves spontaneous pain
Dorsal root ganglion field stimulation (GFS) relieves evoked and spontaneous neuropathic pain by use-dependent blockade of impulse trains through the sensory neuron T-junction, which becomes complete within less than 1 minute for C-type units, also with partial blockade of Aδ units. We used this tool in the spinal nerve ligation (SNL) rat model to selectively block sensory neuron spontaneous activity (SA) of axotomized neurons at the fifth lumbar (L5) level vs blockade of units at the L4 level that remain uninjured but exposed to inflammation. In vivo dorsal root single-unit recordings after SNL showed increased SA i...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Peritraumatic 17β-estradiol levels influence chronic posttraumatic pain outcomes
In conclusion, peritraumatic circulating E2 levels predict CPTP vulnerability in women trauma survivors. In addition, these data suggest that peritraumatic administration of E2 might improve CPTP outcomes for women; further research is needed to test this possibility. (Source: Pain)
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Dynamics of brain function in patients with chronic pain assessed by microstate analysis of resting-state electroencephalography
Chronic pain is a highly prevalent and severely disabling disease that is associated with substantial changes of brain function. Such changes have mostly been observed when analyzing static measures of resting-state brain activity. However, brain activity varies over time, and it is increasingly recognized that the temporal dynamics of brain activity provide behaviorally relevant information in different neuropsychiatric disorders. Here, we therefore investigated whether the temporal dynamics of brain function are altered in chronic pain. To this end, we applied microstate analysis to eyes-open and eyes-closed resting-stat...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Responsiveness of quantitative sensory testing-derived sensory phenotype to disease-modifying intervention in patients with entrapment neuropathy: a longitudinal study
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. Symptom and pain severity para...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Activation of the dorsal, but not the ventral, hippocampus relieves neuropathic pain in rodents
Accumulating evidence suggests hippocampal impairment under the chronic pain phenotype. However, it is unknown whether neuropathic behaviors are related to dysfunction of the hippocampal circuitry. Here, we enhanced hippocampal activity by pharmacological, optogenetic, and chemogenetic techniques to determine hippocampal influence on neuropathic pain behaviors. We found that excitation of the dorsal (DH), but not the ventral (VH) hippocampus induces analgesia in 2 rodent models of neuropathic pain (SNI and SNL) and in rats and mice. Optogenetic and pharmacological manipulations of DH neurons demonstrated that DH-induced an...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Classism in pain assessment and management: the mediating role of female patient dehumanization and perceived life hardship
Compared with racism and sexism, classism in pain assessment and management practices (PAMPs) has been less investigated, and its mediating mechanisms are still unknown. Drawing on 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 PAMPs 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 high) within-subjects. One-hundred sixty-two female medical students (study 1) and 105 female nurses (...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Action of mefloquine/amitriptyline THN101 combination on neuropathic mechanical hypersensitivity in mice
In this study, we further investigated this improvement of amitriptyline action by mefloquine, using the cuff model of neuropathic pain in mice. We first observed that oral mefloquine co-treatment prolonged the effect of amitriptyline on mechanical hypersensitivity by 12 hours after administration. In addition, we showed that this potentiation was not due to pharmacokinetic interactions between the 2 drugs. Besides, lesional and pharmacological approaches showed that the prolonged effect was induced through noradrenergic descending pathways and the recruitment of α2 adrenoceptors. Another connexin blocker, carbenoxol...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Myalgia as a symptom at hospital admission by severe acute respiratory syndrome coronavirus 2 infection is associated with persistent musculoskeletal pain as long-term post-COVID sequelae: a case-control study
In conclusion, myalgia at the acute phase was associated with musculoskeletal pain as long-term post-COVID sequelae. In addition, half of the patients with preexisting pain conditions experienced a persistent exacerbation of their previous syndromes. (Source: Pain)
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Endogenous opioids contribute to the feeling of pain relief in humans
This study provides evidence that endogenous opioids play a role in mediating the pleasant feeling of pain relief in humans. Clinically, the rewarding nature of pain relief and its underlying mechanisms require consideration because of their potential reinforcing effects on behaviors that might be beneficial short-term but maladaptive long-term. (Source: Pain)
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Shedding light on pain for the clinic: a comprehensive review of using functional near-infrared spectroscopy to monitor its process in the brain
Pain is a complex experience that involves sensation, emotion, and cognition. The subjectivity of the traditional pain measurement tools has expedited the interest in developing neuroimaging techniques to monitor pain objectively. Among noninvasive neuroimaging techniques, functional near-infrared spectroscopy (fNIRS) has balanced spatial and temporal resolution; yet, it is portable, quiet, and cost-effective. These features enable fNIRS to image the cortical mechanisms of pain in a clinical environment. In this article, we evaluated pain neuroimaging studies that used the fNIRS technique in the past decade. Starting from ...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Comprehensive Review Source Type: research

Effectiveness of placebo interventions for patients with nonspecific low back pain: a systematic review and meta-analysis
Little is known about the effectiveness of placebo interventions in patients with nonspecific 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 5, 2019. Randomized controlled trials comparing placebo intervention vs no intervention in adult patients with nonspecific LBP were included. Pain intensity, physical functioning, and health-related quality of life measured at short-t...
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

Do endogenous opioids mediate or fine-tune human pain relief?
No abstract available (Source: Pain)
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Commentary Source Type: research

Basic and applied psychology in PAIN: where we have been and where we are headed
No abstract available (Source: Pain)
Source: Pain - November 29, 2021 Category: Anesthesiology Tags: Editorial Source Type: research

Reply to Bordeleau et al.
No abstract available (Source: Pain)
Source: Pain - October 18, 2021 Category: Anesthesiology Tags: Correspondence Source Type: research

Realigning the role of quantitative sensory testing in sensory profiling of patients with and without neuropathic pain
No abstract available (Source: Pain)
Source: Pain - October 18, 2021 Category: Anesthesiology Tags: Correspondence Source Type: research