Cardiac vagal tone as a reliable index of pain chronicity and severity
No abstract available (Source: Pain)
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Correspondence Source Type: research

High levels of cerebrospinal fluid chemokines point to the presence of neuroinflammation in peripheral neuropathic pain: a cross-sectional study of 2 cohorts of patients compared with healthy controls
Abstract Animal models suggest that chemokines are important mediators in the pathophysiology of neuropathic pain. Indeed, these substances have been called “gliotransmitters,” a term that illustrates the close interplay between glial cells and neurons in the context of neuroinflammation and pain. However, evidence in humans is scarce. The aim of the study was to determine a comprehensive cerebrospinal fluid (CSF) inflammatory profile of patients with neuropathic pain. Our hypothesis was that we would thereby find indications of a postulated on-going process of central neuroinflammation. Samples of CSF were c...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Photosensitization of TRPA1 and TRPV1 by 7-dehydrocholesterol: implications for the Smith–Lemli–Opitz syndrome
Abstract Loss-of-function mutations in the enzyme 7-dehydrocholesterol reductase are responsible for the Smith–Lemli–Opitz syndrome, in which 7-dehydrocholesterol (7-DHC) levels are markedly increased in the plasma and tissues of patients. This increase in 7-DHC is probably associated with the painful and itchy photosensitivity reported by the majority of patients with Smith–Lemli–Opitz syndrome. To identify the molecular targets involved in the activation and photosensitization of primary afferents by 7-DHC, we focused on TRPA1 and TRPV1, two ion channels expressed in nociceptive nerve endings an...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

MicroRNA–mediated downregulation of potassium-chloride-cotransporter and vesicular γ-aminobutyric acid transporter expression in spinal cord contributes to neonatal cystitis–induced visceral pain in rats
Abstract Loss of GABAergic inhibition in pain pathways has been considered to be a key component in the development of chronic pain. In the present study, we intended to examine whether miR-92b–mediated posttranscriptional dysregulation of spinal potassium chloride cotransporter (KCC2) and vesicular γ-aminobutyric acid transporter (VGAT) plays a major role in the development and maintenance of long-term visceral hyperalgesia in neonatal zymosan–treated rats. Neonatal cystitis was induced by transurethral zymosan administration from postnatal (P) days 14 to 16 (protocol 1). Two other zymosan protocols we...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Cannabis constituent synergy in a mouse neuropathic pain model
We examined the basis for this phytocannabinoid interaction in a mouse chronic constriction injury (CCI) model of neuropathic pain. Acute systemic administration of THC dose-dependently reduced CCI-induced mechanical and cold allodynia, but also produced motor incoordination, catalepsy, and sedation. Cannabidiol produced a lesser dose-dependent reduction in allodynia, but did not produce the cannabinoid side effects. When co-administered in a fixed ratio, THC and CBD produced a biphasic dose-dependent reduction in allodynia. At low doses, the THC:CBD combination displayed a 200-fold increase in anti-allodynic potency, but ...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Attenuation of early phase inflammation by cannabidiol prevents pain and nerve damage in rat osteoarthritis
Abstract Osteoarthritis (OA) is a multifactorial joint disease, which includes joint degeneration, intermittent inflammation, and peripheral neuropathy. Cannabidiol (CBD) is a noneuphoria producing constituent of cannabis that has the potential to relieve pain. The aim of this study was to determine whether CBD is anti-nociceptive in OA, and whether inhibition of inflammation by CBD could prevent the development of OA pain and joint neuropathy. Osteoarthritis was induced in male Wistar rats (150-175 g) by intra-articular injection of sodium monoiodoacetate (MIA; 3 mg). On day 14 (end-stage OA), joint afferent mechanosens...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Bivalent ligand that activates mu opioid receptor and antagonizes mGluR5 receptor reduces neuropathic pain in mice
This study assessed whether intrathecal MMG22 also is effective in reducing pain of neuropathic origin. Furthermore, we theorized that MMG22 should reduce hyperalgesia in nerve-injured mice in a manner consistent with a synergistic interaction between MOR and mGluR5. Several weeks after spared nerve injury, tactile hypersensitivity was reversed in mice by the intrathecal injection of MMG22 (0.01-10 nmol) but also by its shorter spacer analog, MMG10, with similar potency. The potencies of the bivalent ligands were 10- to 14-fold higher than those of the compounds upon which the bivalent structure was based, the MOR agonist ...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Opioid prescription levels and postoperative outcomes in orthopedic surgery
Abstract Given the basic need for opioids in the perioperative setting, we investigated associations between opioid prescription levels and postoperative outcomes using population-based data of orthopedic surgery patients. We hypothesized that increased opioid amounts would be associated with higher risk for postoperative complications. Data were extracted from the national Premier Perspective database (2006-2013); N = 1,035,578 lower joint arthroplasties and N = 220,953 spine fusions. Multilevel multivariable logistic regression models measured associations between opioid dose prescription and postoperative outcomes, st...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Passive transfer autoimmunity in a mouse model of complex regional pain syndrome
Abstract It has been proposed that complex regional pain syndrome (CRPS) is a posttraumatic autoimmune disease, and we previously observed that B cells are required for the full expression of CRPS-like changes in a mouse tibia fracture CRPS model. The current study used the mouse model to evaluate the progression of postfracture CRPS-like changes in wild-type (WT) and muMT fracture mice lacking B cells and antibodies. The pronociceptive effects of injecting WT fracture mouse serum antibodies into muMT fracture mice were also evaluated. Postfracture pain behaviors transitioned from being initially dependent on both innate...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Tumor necrosis factor alpha secreted from oral squamous cell carcinoma contributes to cancer pain and associated inflammation
In this study, we used 2 oral cancer mouse models: a cell line supernatant injection model and the 4-nitroquinoline-1-oxide (4NQO) chemical carcinogenesis model. We used the 2 models to study changes in immune cell infiltrate and orofacial nociception associated with oral squamous cell carcinoma (oSCC). Oral cancer cell line supernatant inoculation and 4NQO-induced oSCC resulted in functional allodynia and neuronal sensitization of trigeminal tongue afferent neurons. Although the infiltration of immune cells is a prominent component of both oral cancer models, our use of immune-deficient mice demonstrated that oral cancer&...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Multiple sites and actions of gabapentin-induced relief of ongoing experimental neuropathic pain
Abstract Gabapentin (GBP) is a first-line therapy for neuropathic pain, but its mechanisms and sites of action remain uncertain. We investigated GBP-induced modulation of neuropathic pain following spinal nerve ligation (SNL) in rats. Intravenous or intrathecal GBP reversed evoked mechanical hypersensitivity and produced conditioned place preference (CPP) and dopamine (DA) release in the nucleus accumbens (NAc) selectively in SNL rats. Spinal GBP also significantly inhibited dorsal horn wide-dynamic-range neuronal responses to a range of evoked stimuli in SNL rats. By contrast, GBP microinjected bilaterally into the rost...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Monomethyl fumarate inhibits pain behaviors and amygdala activity in a rat arthritis model
Abstract Neuroplasticity in the amygdala, a brain center for emotions, leads to increased neuronal activity and output that can generate emotional-affective behaviors and modulate nocifensive responses. Mechanisms of increased activity in the amygdala output region (central nucleus, CeA) include increased reactive oxygen species, and so we explored beneficial effects of monomethyl fumarate (MMF), which can have neuroprotective effects through the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) antioxidant response pathway. Systemic (intraperitoneal) MMF dose-dependently inhibited vocalizations and mechanosensitivity (...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Cerebral white matter structure is disrupted in Gulf War Veterans with chronic musculoskeletal pain
Abstract Chronic musculoskeletal pain (CMP) affects ∼25% of the 700,000 Veterans deployed during the Persian Gulf War (1990-1991). The cause of their pain is unknown, and there are no efficacious treatments. A small body of literature suggests that brain abnormalities exist in Gulf War Veterans (GVs), yet relationships between brain abnormalities and disease symptoms remain largely unexplored. Our purpose was to compare white matter (WM) integrity between GVCMP and matched, healthy Veteran controls (GVCO) and investigate relationships between cerebral WM integrity and symptoms. Thirty GVCMP and 31 controls completed ...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Emotional awareness and expression therapy, cognitive behavioral therapy, and education for fibromyalgia: a cluster-randomized controlled trial
Abstract Patients with fibromyalgia (FM) experience increased lifetime levels of psychosocial adversity, trauma, and emotional conflict. To address these risk factors, we developed emotion awareness and expression therapy (EAET) and tested its benefits against an active control condition, FM education, and the field's gold standard intervention for FM, cognitive behavioral therapy (CBT) for symptom management. Adults with FM (N = 230) formed 40 treatment groups, which were randomized to EAET, CBT, or education and given 8, 90-minute sessions. Patient-reported outcomes were assessed at baseline, posttreatment, and 6-month...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Sensory phenotype and risk factors for painful diabetic neuropathy: a cross-sectional observational study
Abstract Different sensory profiles in diabetic distal symmetrical sensory-motor polyneuropathy (DSPN) may be associated with pain and the responsiveness to analgesia. We aimed to characterize sensory phenotypes of patients with painful and painless diabetic neuropathy and to assess demographic, clinical, metabolic, and electrophysiological parameters related to the presence of neuropathic pain in a large cohort of well-defined DSPN subjects. This observational cross-sectional multi-center cohort study (performed as part of the ncRNAPain EU consortium) of 232 subjects with nonpainful (n = 74) and painful (n = 158) DSPN a...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Distinct behavioral responses evoked by selective optogenetic stimulation of the major TRPV1+ and MrgD+ subsets of C-fibers
Abstract Primary C-fiber nociceptors are broadly divided into peptidergic and nonpeptidergic afferents. TRPV1 is a thermosensitive cation channel mainly localized in peptidergic nociceptors, whereas MrgD is a sensory G protein–coupled receptor expressed in most nonpeptidergic nociceptive afferents. TRPV1+ and MrgD+ fibers have been reported to be primarily involved in thermal and mechanical nociception, respectively. Yet, their functional assessment in somatosensory transmission relied on ablation strategies that do not account for compensatory mechanisms. To achieve selective activation of these 2 major subsets of...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Is the rationale more important than deception? A randomized controlled trial of open-label placebo analgesia
Abstract Research on open-label placebos questions whether deception is a necessary characteristic of placebo effects. Yet, comparisons between open-label and deceptive placebos (DPs) are lacking. We therefore assessed effects of open-label placebos and DPs in comparison with no treatment (NT) with a standardized experimental heat pain paradigm in a randomized controlled trial in healthy participants. Participants (N = 160) were randomly assigned to NT, open-label placebo without rationale (OPR-), open-label placebo with rationale (OPR+), and DP. We conducted baseline and posttreatment measurements of heat pain threshold...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

CRISPR/Cas9 editing of Nf1 gene identifies CRMP2 as a therapeutic target in neurofibromatosis type 1-related pain that is reversed by (S)-Lacosamide
Abstract Neurofibromatosis type 1 (NF1) is a rare autosomal dominant disease linked to mutations of the Nf1 gene. Patients with NF1 commonly experience severe pain. Studies on mice with Nf1 haploinsufficiency have been instructive in identifying sensitization of ion channels as a possible cause underlying the heightened pain suffered by patients with NF1. However, behavioral assessments of Nf1+/− mice have led to uncertain conclusions about the potential causal role of Nf1 in pain. We used the clustered regularly interspaced short palindromic repeats (CRISPR)-associated 9 (CRISPR/Cas9) genome editing system to crea...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Discovery of endogenous opioid systems: what it has meant for the clinician's understanding of pain and its treatment
Abstract Before the discovery of the endogenous opioid system in the 1970s, opioids were understood only through the lens of opioid drug effects. Opium produced sleep, pain relief, and addiction. Once a variety of opioids had been extracted from opium, and still others synthesized chemically, it became clear that there must be endogenous receptors to explain differential drug effects. So, the search was on to identify the receptors, and subsequently their endogenous ligands. Even then, the consequential ways in which the endogenous opioid system influences the way we respond to the environment and survive took time to un...
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Pain Classics Source Type: research

Peripheral afferents and spinal inhibitory system in dynamic and static mechanical allodynia
No abstract available (Source: Pain)
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Topical Review Source Type: research

Hijacking the endogenous opioid system to treat pain: who thought it would be so complicated?
No abstract available (Source: Pain)
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Commentaries Source Type: research

Shedding light on the contribution of different c-fibre nociceptors to nocifensive behavior
No abstract available (Source: Pain)
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Commentaries Source Type: research

Hypoalgesic placebo effects can occur with transparent disclosures
No abstract available (Source: Pain)
Source: Pain - November 21, 2017 Category: Anesthesiology Tags: Commentaries Source Type: research

Reply
No abstract available (Source: Pain)
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Correspondence Source Type: research

Problematic use of prescribed opioids for chronic noncancer pain—no scarcity of data outside the United States
No abstract available (Source: Pain)
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Correspondence Source Type: research

Pain and itch outcome trajectories differ among European American and African American survivors of major thermal burn injury
Abstract AbstractMore than half of individuals experiencing major thermal burn injury (MThBI) receive an autologous skin graft (autograft), in which skin is removed from a healthy “donor” site and transplanted to the burn site. Persistent pain and itch at the graft site are major causes of suffering and disability in MThBI survivors. African Americans have a higher risk of MThBI, and in other clinical settings African Americans experience a greater burden of pain and itch relative to European Americans. However, to our knowledge, ethnic differences in skin graft site pain and itch outcomes after MThBI have not ...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Bleeding out the quality-adjusted life years: evaluating the burden of primary dysmenorrhea using time trade-off and willingness-to-pay methods
Abstract AbstractPrimary dysmenorrhea (PD), or painful menstruation in the absence of identified uterine pathology, affects 5 to 9 in every 10 reproductive-aged women. Despite its high prevalence, just a few studies with very small patient numbers have focused on health-related quality of life impairment in PD. We aimed to assess health-related quality of life values for a severe and a mild hypothetical PD health state using 10-year time trade-off and willingness-to-pay methods. In 2015, a nationwide convenience sample of women, aged between 18 and 40 years, was recruited using an Internet-based cross-sectional survey in H...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Therapeutic potential for leukocyte elastase in chronic pain states harboring a neuropathic component
Abstract AbstractNeuropathic pain is an integral component of several chronic pain conditions and poses a major health problem worldwide. Despite emerging understanding of mechanisms behind neuropathic pain, the available treatment options are still limited in efficacy or associated with side effects, therefore making it necessary to find viable alternatives. In a genetic screen, we recently identified SerpinA3N, a serine protease inhibitor secreted in response to nerve damage by the dorsal root ganglion neurons and we showed that SerpinA3N acts against induction of neuropathic pain by inhibiting the T-cell- and neutrophil...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

The role of spatial frequency information in the decoding of facial expressions of pain: a novel hybrid task
In this study, we investigated whether perpetual preference differences exist for low-SF and high-SF pain information. A novel hybrid expression paradigm was used in which 2 different expressions, one containing low-SF information and the other high-SF information, were combined in a facial hybrid. Participants are instructed to identify the core expression contained within the hybrid, allowing for the measurement of SF information preference. Three experiments were conducted (46 participants in each) that varied the expressions within the hybrid faces: respectively pain-neutral, pain-fear, and pain-happiness. In order to ...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Age-dependent plasticity in endocannabinoid modulation of pain processing through postnatal development
Abstract AbstractSignificant age- and experience-dependent remodelling of spinal and supraspinal neural networks occur, resulting in altered pain responses in early life. In adults, endogenous opioid peptide and endocannabinoid (ECs) pain control systems exist which modify pain responses, but the role they play in acute responses to pain and postnatal neurodevelopment is unknown. Here, we have studied the changing role of the ECs in the brainstem nuclei essential for the control of nociception from birth to adulthood in both rats and humans. Using in vivo electrophysiology, we show that substantial functional changes occur...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Dissecting the role of the CRMP2–neurofibromin complex on pain behaviors
Abstract AbstractNeurofibromatosis type 1 (NF1), a genetic disorder linked to inactivating mutations or a homozygous deletion of the Nf1 gene, is characterized by tumorigenesis, cognitive dysfunction, seizures, migraine, and pain. Omic studies on human NF1 tissues identified an increase in the expression of collapsin response mediator protein 2 (CRMP2), a cytosolic protein reported to regulate the trafficking and activity of presynaptic N-type voltage-gated calcium (Cav2.2) channels. Because neurofibromin, the protein product of the Nf1 gene, binds to and inhibits CRMP2, the neurofibromin–CRMP2 signaling cascade will...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Role of neurturin in spontaneous itch and increased nonpeptidergic intraepidermal fiber density in a mouse model of psoriasis
Abstract AbstractPsoriasis is often accompanied by itch, but the mechanisms behind this symptom remain elusive. Dynamic changes in epidermal innervation have been observed under chronic itch conditions. Therefore, we investigated whether epidermal innervation is altered in the imiquimod-induced psoriasis mouse model, whether blockade of neurotrophic growth factor signaling can reduce these changes, and whether this system can impact psoriatic itch. Over the 7-day time course of imiquimod treatment, the density of epidermal nonpeptidergic nerves significantly increased, whereas the density of peptidergic nerves significantl...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Psychological interventions that target sleep reduce pain catastrophizing in knee osteoarthritis
This study examined if interventions targeting sleep found to be effective in improving sleep in KOA also reduce pain catastrophizing measured as a trait through the pain catastrophizing scale and measured as a daytime and nocturnal state through daily diaries. Secondary analyses were conducted on data collected as part of a randomized controlled trial assessing the effectiveness of cognitive behavioral therapy for insomnia in patients with KOA at 5 different time points: pretreatment, midtreatment and posttreatment and at 3- and 6-month follow-up. One hundred patients diagnosed with KOA and insomnia were randomized to rec...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Nervous system delivery of antilysophosphatidic acid antibody by nasal application attenuates mechanical allodynia after traumatic brain injury in rats
Abstract AbstractLysophosphatidic acid (LPA) is a bioactive lipid that impacts neurological outcomes after neurotrauma by inhibiting neuroregeneration, promoting inflammation, and contributing to behavioral deficits. Blocking LPA signaling with a novel anti-LPA monoclonal antibody (mAb) is neuroprotective after traumatic brain injury (TBI) if given to injured animals whose blood–brain barrier (BBB) has been compromised. It is hypothesized that the anti-LPA mAb could improve chronic pain initiated by TBI. However, poor brain penetration after systemic application of the antibody makes access to the central nervous sys...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Bulleyaconitine A preferably reduces tetrodotoxin-sensitive sodium current in uninjured dorsal root ganglion neurons of neuropathic rats probably via inhibition of protein kinase C
Abstract AbstractOral Bulleyaconitine A (BLA) is effective for treating neuropathic pain in human patients, but the underlying mechanism is poorly understood. Here, we tested whether BLA blocked voltage-gated sodium channels (VGSCs) in dorsal root ganglion (DRG) neurons. Compelling evidence shows that voltage-gated sodium channels are upregulated in uninjured DRG neurons but downregulated in injured ones following peripheral nerve injury. We found that BLA preferably inhibited Na+ currents in uninjured DRG neurons in neuropathic rats. Compared to sham rats, IC50 values for resting and inactivated Na+ currents were 113 and ...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Cyclin-dependent kinase 5 modulates the P2X2a receptor channel gating through phosphorylation of C-terminal threonine 372
Abstract AbstractThe purinergic P2X2 receptor (P2X2R) is an adenosine triphosphate–gated ion channel widely expressed in the nervous system. Here, we identified a putative cyclin-dependent kinase 5 (Cdk5) phosphorylation site in the full-size variant P2X2aR (372TPKH375), which is absent in the splice variant P2X2bR. We therefore investigated the effects of Cdk5 and its neuronal activator, p35, on P2X2aR function. We found an interaction between P2X2aR and Cdk5/p35 by co-immunofluorescence and co-immunoprecipitation in HEK293 cells. We also found that threonine phosphorylation was significantly increased in HEK293 cel...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Day-to-day experience in resolution of pain after surgery
Abstract AbstractWe know little about the individual pain experience of patients recovering from surgery in the first weeks after hospital discharge. Here, we examine individual differences in the day-to-day experience after 2 major surgeries: lower limb total major joint arthroplasty (TJA) and cesarean delivery (CD). Fifty-five TJA patients and 157 CD patients were recruited to complete questionnaires and record their daily pain experiences after surgery. After hospital discharge, patients recorded their pain intensity once daily for 60 days (CD) or twice daily for 2 weeks, once daily for 2 weeks, weekly for 8 weeks, and ...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Reactive oxygen species affect spinal cell type-specific synaptic plasticity in a model of neuropathic pain
This study examined the roles of 2 biologically important ROS––superoxide [·O2] and hydroxyl radicals [·OH]––in neuropathic mechanical hyperalgesia and cell type-specific spinal synaptic plasticity. The [·O2] donor induced stronger mechanical hyperalgesia than the [·OH] donor in naive mice. The [·O2] scavenger showed greater antihyperalgesic effect than [·OH] scavengers in the spinal nerve ligation (SNL) mouse model of neuropathic pain. In addition, the [·O2] donor induced both STTn-LTP and GABAn-LTD, but the [·OH] donor induced only GABAn-LTD....
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Autonomic responses to tonic pain are more closely related to stimulus intensity than to pain intensity
Abstract AbstractPain serves the protection of the body by translating noxious stimulus information into a subjective percept and protective responses. Such protective responses rely on autonomic responses that allocate energy resources to protective functions. However, the precise relationship between objective stimulus intensity, subjective pain intensity, autonomic responses, and brain activity is not fully clear yet. Here, we addressed this question by continuously recording pain ratings, skin conductance, heart rate, and electroencephalography during tonic noxious heat stimulation of the hand in 39 healthy human subje...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Peripheral oxytocin receptors inhibit the nociceptive input signal to spinal dorsal horn wide-dynamic-range neurons
This study shows that OTRs are expressed in the terminal nerve endings and are able to inhibit nociceptive neuronal firing. Indeed, local peripheral OT blocked the first sensorial activity of Aδ and C fibers recorded in the spinal cord neurons. Furthermore, using the formalin behavioral nociceptive test, we demonstrated that only ipsilateral OTR activation inhibits pain behavior. Our data are reinforced by the fact that the OTR protein is expressed in the sciatic nerve. Consistent with this, immunofluorescence of primary afferent fibers suggest that OTRs could be located in nociceptive-specific terminals of the skin....
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Fully implantable, battery-free wireless optoelectronic devices for spinal optogenetics
Abstract AbstractThe advent of optogenetic tools has allowed unprecedented insights into the organization of neuronal networks. Although recently developed technologies have enabled implementation of optogenetics for studies of brain function in freely moving, untethered animals, wireless powering and device durability pose challenges in studies of spinal cord circuits where dynamic, multidimensional motions against hard and soft surrounding tissues can lead to device degradation. We demonstrate here a fully implantable optoelectronic device powered by near-field wireless communication technology, with a thin and flexible ...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Research Paper Source Type: research

Defining chronic pain in epidemiological studies: a systematic review and meta-analysis
The objective was to document the operational definitions applied in epidemiological studies of chronic pain and to examine whether pain definitions and other methodological factors are systematically related to prevalence estimates. MEDLINE, EMBASE, and PsychINFO were searched for original research reports with study samples of at least 1000 individuals, excluding studies of less than 5 out of 15 selected body regions and studies solely concerned with specific pain conditions. Meta-analyses and meta-regressions were applied with random effects models; covariates were geography, sampling year, survey method, sampling frame...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

The prevalence of neuropathic pain is high after treatment for breast cancer: a systematic review
Abstract AbstractPain is common, but often poorly managed after breast cancer treatment. Screening questionnaires and the Neuropathic Pain Special Interest Group (NeuPSIG) criteria are 2 clinical approaches used to determine whether pain has neuropathic components, which may enable better pain management. The aims of this review were (1) to synthesise data from the literature on neuropathic pain prevalence in women after breast cancer treatment; (2) to investigate whether the prevalence of neuropathic pain differed between studies using screening questionnaires and the NeuPSIG criteria. We searched for studies that adminis...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

Observe to get pain relief: current evidence and potential mechanisms of socially learned pain modulation
No abstract available (Source: Pain)
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Topical Review Source Type: research

Beyond solicitousness: a comprehensive review on informal pain-related social support
Abstract AbstractAdults with chronic pain cite social support (SS) as an important resource. Research has mostly focused on general SS or pain-specific solicitousness, resulting in a limited understanding of the role of SS in pain experiences. Drawing on SS theoretical models, this review aimed to understand how pain-related SS has been conceptualized and measured and how its relationship with pain experiences has been investigated. Arksey and O'Malley scoping review framework guided the study. A database search (2000-2015) was conducted in PsycINFO, CINAHL, MEDLINE, and EMBASE using a combination of subject headings/keywo...
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Comprehensive Review Source Type: research

Pain-autonomic relationships: implications for experimental design and the search for an “objective marker” for pain
No abstract available (Source: Pain)
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Commentaries Source Type: research

Oxytocin: pain relief in skin
No abstract available (Source: Pain)
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Commentaries Source Type: research

A new optogenetic device for spinal cord control of pain
No abstract available (Source: Pain)
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Commentaries Source Type: research

In memoriam: Professor Stephen J. Morley (1950–2017)
No abstract available (Source: Pain)
Source: Pain - October 26, 2017 Category: Anesthesiology Tags: Obituary Source Type: research

Racial and ethnic differences in experimental pain sensitivity: systematic review and meta-analysis: Erratum.
No abstract available (Source: Pain)
Source: Pain - September 30, 2017 Category: Anesthesiology Tags: Erratum Source Type: research