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Cisplatin is a potent chemotherapeutic drug that is widely used in the treatment of various solid cancers. However, its clinical effectiveness is strongly limited by frequent severe adverse effects, in particular nephrotoxicity and chemotherapy-induced peripheral neuropathy. Thus, there is an urgent medical need to identify novel strategies that limit cisplatin-induced toxicity. In the present study, we show that the FDA-approved adenosine A2A receptor antagonist istradefylline (KW6002) protected from cisplatin-induced nephrotoxicity and neuropathic pain in mice with or without tumors. Moreover, we also demonstrate that the antitumoral properties of cisplatin were not altered by istradefylline in tumor-bearing mice and could even be potentiated. Altogether, our results support the use of istradefylline as a valuable preventive approach for the clinical management of patients undergoing cisplatin treatment.
Learn More >Pain relief by vibrotactile touch is a common human experience. Previous neurophysiological investigations of its underlying mechanism in animals focused on spinal circuits, while human studies suggested the involvement of supraspinal pathways. Here, we examine the role of primary somatosensory cortex (S1) in touch-induced mechanical and heat analgesia. We found that, in mice, vibrotactile reafferent signals from self-generated whisking significantly reduce facial nociception, which is abolished by specifically blocking touch transmission from thalamus to the barrel cortex (S1B). Using a signal separation algorithm that can decompose calcium signals into sensory-evoked, whisking, or face-wiping responses, we found that the presence of whisking altered nociceptive signal processing in S1B neurons. Analysis of S1B population dynamics revealed that whisking pushes the transition of the neural state induced by noxious stimuli toward the outcome of non-nocifensive actions. Thus, S1B integrates facial tactile and noxious signals to enable touch-mediated analgesia.
Learn More >Specialized pro-resolving mediators (SPMs) have demonstrated potent analgesic actions in animal models of pathological pain. The actions of SPMs in acute and chronic itch are currently unknown. Recently, n-3 docosapentaenoic acid (DPA) was found to be a substrate for the biosynthesis of several novel families of SPMs; 3-oxa-PD1n-3 DPA (3-oxa-PD1) is an oxidation-resistant metabolic stable analogue of the n-3 DPA-derived protectin D1 (PD1). Herein, we demonstrate that 3-oxa-PD1 effectively reduces both acute and chronic itch in mouse models. Intrathecal injection of 3-oxa-PD1 (100 ng) reduced acute itch induced by either histamine, chloroquine, or morphine. Furthermore, intrathecal 3-oxa-PD1 effectively reduced chronic itch, induced by cutaneous T cell lymphoma (CTCL), allergic contact dermatitis with dinitrofluorobenzene, and psoriasis by imiquimod. Intratumoral injection of 3-oxa-PD1 also suppressed CTCL-induced chronic itch. Strikingly, this anti-pruritic effect lasted for several weeks after 1-week of intrathecal 3-oxa-PD1 treatment. Whole-cell recordings revealed significant increase in excitatory postsynaptic currents in spinal dorsal horn (SDH) neurons of CTCL mice, but this increase was blocked by 3-oxa-PD1. 3-oxa-PD1 further increased inhibitory postsynaptic currents in SDH neurons of CTCL mice. CTCL increased the spinal levels of lipocalin-2 (LCN2), an itch mediator produced by astrocytes. 3-oxa-PD1 suppressed LCN2 production in CTCL mice and LCN2 secretion in astrocytes. Finally, CTCL-induced anxiety was alleviated by intrathecal 3-oxa-PD1. Our findings suggest that 3-oxa-PD1 potently inhibits acute and chronic itch via regulation of excitatory/inhibitory synaptic transmission and astroglial LCN2 production. Therefore, stable SPM analogs such as 3-oxa-PD1 could be useful to treat pruritus associated with different skin injuries.
Learn More >Treatment with opioids not only inhibits nociceptive transmission but also elicits a rebound and persistent increase in primary afferent input to the spinal cord. Opioid-elicited long-term potentiation (LTP) from TRPV1-expressing primary afferents plays a major role in opioid-induced hyperalgesia and analgesic tolerance. Here, we determined whether opioid-elicited LTP involves vesicular glutamate transporter-2 (VGluT2) or vesicular GABA transporter (VGAT) neurons in the spinal dorsal horn of male and female mice and identified underlying signaling mechanisms. Spinal cord slice recordings revealed that µ-opioid receptor (MOR) stimulation with DAMGO initially inhibited dorsal root-evoked EPSCs in 87% VGluT2 neurons and subsequently induced LTP in 49% of these neurons. Repeated morphine treatment increased the prevalence of VGluT2 neurons displaying LTP with a short onset latency. In contrast, DAMGO inhibited EPSCs in 46% VGAT neurons but did not elicit LTP in any VGAT neurons even in morphine-treated mice. Spinal superficial laminae were densely innervated by MOR-containing nerve terminals and were occupied by mostly VGluT2 neurons and few VGAT neurons. Furthermore, conditional knockout in dorsal root ganglion neurons diminished DAMGO-elicited LTP in lamina II neurons and attenuated hyperalgesia and analgesic tolerance induced by repeated treatment with morphine. In addition, DAMGO-elicited LTP in VGluT2 neurons was abolished by protein kinase C inhibition, gabapentin, knockout, or disrupting the α2δ-1-NMDA receptor interaction with an α2δ-1 C terminus peptide. Thus, brief MOR stimulation distinctively potentiates nociceptive primary afferent input to excitatory dorsal horn neurons via α2δ-1-coupled presynaptic NMDA receptors, thereby causing hyperalgesia and reducing opioids' analgesic actions.Opioid drugs are potent analgesics for treating severe pain and are commonly used during general anesthesia. However, opioid use often induces pain hypersensitivity, rapid loss of analgesic efficacy, and dose escalation, which can cause dependence, addiction, and even overdose fatality. This study demonstrates for the first time that brief opioid exposure preferentially augments primary sensory input to genetically identified glutamatergic excitatory, but not GABAergic/glycinergic inhibitory, neurons in nociceptive dorsal horn circuits. This opioid-elicited synaptic plasticity is cell type-specific and mediated by protein kinase C- and α2δ-1-dependent activation of NMDA receptors at primary sensory nerve terminals. These findings elucidate how intraoperative use of opioids aggravates postoperative pain and increases opioid consumption and suggest new strategies to improve opioid analgesic efficacy.
Learn More >Chronic pain involves sensitization of nociceptors and synaptic transmission of painful signals in nociceptive circuits in the dorsal horn of the spinal cord. We investigated the contribution of clathrin-dependent endocytosis to sensitization of nociceptors by G protein-coupled receptors (GPCRs) and to synaptic transmission in spinal nociceptive circuits. We determined whether therapeutic targeting of endocytosis could ameliorate pain. mRNA encoding dynamin (Dnm) 1-3 and adaptor-associated protein kinase 1 (AAK1), which mediate clathrin-dependent endocytosis, were localized to primary sensory neurons of dorsal root ganglia of mouse and human and to spinal neurons in the dorsal horn of the mouse spinal cord by RNAScope®. When injected intrathecally to mice, Dnm and AAK1 siRNA or shRNA knocked-down Dnm and AAK1 mRNA in dorsal root ganglia neurons, reversed mechanical and thermal allodynia and hyperalgesia, and normalized non-evoked behavior in preclinical models of inflammatory and neuropathic pain. Intrathecally administered inhibiters of clathrin, Dnm and AAK1 also reversed allodynia and hyperalgesia. Disruption of clathrin, Dnm and AAK1 did not affect normal motor functions of behaviors. Patch clamp recordings of dorsal horn neurons revealed that Dnm1 and AAK1 disruption inhibited synaptic transmission between primary sensory neurons and neurons in lamina I/II of the spinal cord dorsal horn by suppressing release of synaptic vesicles from presynaptic primary afferent neurons. Patch clamp recordings from dorsal root ganglion nociceptors indicated that Dnm siRNA prevented sustained GPCR-mediated sensitization of nociceptors. By disrupting synaptic transmission in the spinal cord and blunting sensitization of nociceptors, endocytosis inhibitors offer a therapeutic approach for pain treatment.
Learn More >Endometriosis affects approximately 190 million women and people assigned female at birth worldwide. It is a chronic, inflammatory, gynecologic disease marked by the presence of endometrial-like tissue outside the uterus, which in many patients is associated with debilitating painful symptoms. Patients with endometriosis are also at greater risk of infertility, emergence of fatigue, multisite pain, and other comorbidities. Thus, endometriosis is best understood as a condition with variable presentation and effects at multiple life stages. A long diagnostic delay after symptom onset is common, and persistence and recurrence of symptoms despite treatment is common. This review discusses the potential genetic, hormonal, and immunologic factors that lead to endometriosis, with a focus on current diagnostic and management strategies for gynecologists, general practitioners, and clinicians specializing in conditions for which patients with endometriosis are at higher risk. It examines evidence supporting the different surgical, pharmacologic, and non-pharmacologic approaches to treating patients with endometriosis and presents an easy to adopt step-by-step management strategy. As endometriosis is a multisystem disease, patients with the condition should ideally be offered a personalized, multimodal, interdisciplinary treatment approach. A priority for future discovery is determining clinically informative sub-classifications of endometriosis that predict prognosis and enhance treatment prioritization.
Learn More >The trigeminal sensory innervation of the cranial meninges is thought to serve a nociceptive function and mediate headache pain. However, the activity of meningeal afferents under natural conditions in awake animals remains unexplored. Here, we used two- and three-dimensional two-photon calcium imaging to track the activity of meningeal afferent fibers in awake mice. Surprisingly, a large subset of afferents was activated during non-noxious conditions such as locomotion. We estimated locomotion-related meningeal deformations and found afferents with distinct dynamics and tuning to various levels of meningeal expansion, compression, shearing, and Z-axis motion. Further, these mechanosensitive afferents were often tuned to distinct directions of meningeal expansion or compression. Thus, in addition to their role in headache-related pain, meningeal sensory neurons track the dynamic mechanical state of the meninges under natural conditions.
Learn More >Medication management and cognitive behavioral therapy (CBT) are commonly used treatments for chronic low back pain (CLBP). However, little evidence is available comparing the effectiveness of these approaches.
Learn More >Chronic pain disorders are often associated with negative emotions, including anxiety and depression. The central nucleus of the amygdala (CeA) has emerged as an integrative hub for nociceptive and affective components during central pain development. Prior adverse injuries are precipitating factors thought to transform nociceptors into a primed state for chronic pain. However, the cellular basis underlying the primed state and the subsequent development of chronic pain remains unknown. Here, we investigated the cellular and synaptic alterations of the CeA in a mouse model of chronic muscle pain. In these mice, local infusion of pregabalin, a clinically approved drug for fibromyalgia and other chronic pain disorders, into the CeA or chemogenetic inactivation of the somatostatin-expressing CeA (CeA-SST) neurons during the priming phase prevented the chronification of pain. Further, electrophysiological recording revealed that the CeA-SST neurons had increased excitatory synaptic drive and enhanced neuronal excitability in the chronic pain states. Finally, either chemogenetic inactivation of the CeA-SST neurons or pharmacological suppression of the nociceptive afferents from the brainstem to the CeA-SST neurons alleviated chronic pain and anxio-depressive symptoms. These data raise the possibility of targeting treatments to CeA-SST neurons to prevent central pain sensitization.
Learn More >This study investigated the tolerability and preliminary efficacy of duloxetine as an alternative nonopioid therapeutic option for the prevention of persistent musculoskeletal pain (MSP) among adults presenting to the emergency department with acute MSP after trauma or injury. In this randomized, double-blind, placebo-controlled study, eligible participants (n = 78) were randomized to 2 weeks of a daily dose of one of the following: placebo (n = 27), 30 mg duloxetine (n = 24), or 60 mg duloxetine (n = 27). Tolerability, the primary outcome, was measured by dropout rate and adverse effects. Secondary outcomes assessed drug efficacy as measured by (1) the proportion of participants with moderate to severe pain (numerical rating scale ≥ 4) at 6 weeks (pain persistence); and (2) average pain by group over the six-week study period. We also explored treatment effects by type of trauma (motor vehicle collision [MVC] vs non-MVC). In both intervention groups, duloxetine was well tolerated and there were no serious adverse events. There was a statistically significant difference in pain over time for the 60 mg vs placebo group (P = 0.03) but not for the 30 mg vs placebo group (P = 0.51). In both types of analyses, the size of the effect of duloxetine was larger in MVC vs non-MVC injury. Consistent with the role of stress systems in the development of chronic pain after traumatic stress, our data indicate duloxetine may be a treatment option for reducing the transition from acute to persistent MSP. Larger randomized controlled trials are needed to confirm these promising results.
Learn More >Chronic pain is a highly prevalent health problem especially in rural regions. There is a dearth of comprehensive pain management programs particularly in rural areas.
Learn More >To identify predictors of acute treatment optimization with prescription drugs among people with episodic migraine.
Learn More >Peripherally active tetrapeptides as selective κ opioid receptor (KOR) agonists have been prepared in good overall yields and high purity following solid-phase peptide synthesis via Fmoc protection strategy. Structural modifications at the first and second position of the FF(d-Nle)R-NH () were contemplated with aromatic side chains containing d-amino acids, such as (d)-F-Phe, (d)-F-Phe, (d)-F-Phe, which led to highly selective and efficacious KOR agonists endowed with strong antinociceptive activity following intravenous (i.v.) and subcutaneous (s.c.) administration in the tail flick and formalin tests. These results suggest potential clinical applications in the treatment of neuropathic and inflammatory pain.
Learn More >The amygdala is a critical brain site for regulation of emotion-associated behaviors such as pain and anxiety. Recent studies suggest that differential cell types and synaptic circuits within the amygdala complex mediate interacting and opposing effects on emotion and pain. However, the underlying cellular and circuit mechanisms are poorly understood at present. Here we used optogenetics combined with electrophysiological analysis of synaptic inputs to investigate pain-induced synaptic plasticity within the amygdala circuits in rats. We found that 50% of the cell population in the lateral division of the central nucleus of the amygdala (CeAl) received glutamate inputs from both basolateral amygdala (BLA) and from the parabrachial nucleus (PBN), and 39% of the remaining CeAl cells received glutamate inputs only from PBN. Inflammatory pain lasting 3 days, which induced anxiety, produced sensitization in synaptic activities of the BLA-CeAl-medial division of CeA (CeAm) pathway primarily through a postsynaptic mechanism. Moreover, in CeAl cells receiving only PBN inputs, pain significantly augmented the synaptic strength of the PBN inputs. In contrast, in CeAl cells receiving both BLA and PBN inputs, pain selectively increased the synaptic strength of BLA inputs, but not the PBN inputs. Electrophysiological analysis of synaptic currents showed that the increased synaptic strength in both cases involved a postsynaptic mechanism. These findings reveal two main populations of CeAl cells that have differential profiles of synaptic inputs and show distinct plasticity in their inputs in response to anxiety-associated pain, suggesting that the specific input plasticity in the two populations of CeAl cells may encode a different role in amygdala regulation of pain and emotion.
Learn More >Identification of long-term post-COVID-19 symptoms among hospitalized and nonhospitalized patients is needed.
Learn More >Itch (pruritus) is a sensation that drives a desire to scratch, a behavior observed in many animals. Although generally short-lasting and not causing harm, there are several pathological conditions where chronic itch is a hallmark symptom and in which prolonged scratching can induce damage. Finding medications to counteract the sensation of chronic itch has proven difficult due to the molecular complexity that involves a multitude of triggers, receptors and signaling pathways between skin, immune and nerve cells. While much has been learned about pruritus from animal models, they have limitations that corroborate the necessity for a transition to more human disease-like models. Also, reducing animal use should be encouraged in research. However, conducting human experiments can also be ethically challenging. Thus, there is a clear need for surrogate models to be used in pre-clinical investigation of the mechanisms of itch. Most models used for itch research focus on the use of known pruritogens. For this, sensory neurons and different types of skin and/or immune cells are stimulated in 2D or 3D co-culture, and factors such as neurotransmitter or cytokine release can be measured. There are however limitations of such simplistic models. For example, not all naturally occurring cell types are present and there is also no connection to the itch-sensing organ, the central nervous system (CNS). Nevertheless, models offer a chance to investigate otherwise inaccessible specific cell-cell interactions and molecular pathways. In recent years, stem cell-based approaches and human primary cells have emerged as viable alternatives to standard cell lines or animal tissue. As models have increased in their complexity, further opportunities for more elaborated means of investigating itch have been developed. In this review, we introduce the latest concepts of itch and discuss the advantages and limitations of current models, which provide valuable contributions to pruritus research and might help to meet the unmet clinical need for more refined anti-pruritic substances.
Learn More >Bone cancer pain (BCP) is one of the most common types of pain in cancer patients which compromises the patient's functional status, quality of life, and survival. Central hyperalgesia has increasingly been identified as a crucial factor of BCP, especially in the medial prefrontal cortex (mPFC) which is the main cortical area involved in the process of pain and consequent negative emotion. To explore the genetic changes in the mPFC during BCP occurrence and find possible targets for prediction, we performed transcriptome sequencing of mPFC in the BCP rat model and found a total of 147 differentially expressed mRNAs (DEmRNAs). A protein-protein interaction (PPI) network revealed that the DEmRNAs mainly participate in the inflammatory response. Meanwhile, microglia and astrocytes were activated in the mPFC of BCP rats, further confirming the presence of neuroinflammation. In addition, Gene Ontology (GO) analysis showed that DEmRNAs in the mPFC are mainly involved in antigen processing, presentation of peptide antigen, and immune response, occurring in the MHC protein complex. Besides, the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed that DEmRNAs are mainly enriched in the pathways of phagosome, staphylococcus aureus infection, and antigen processing, in which MHCII participate. Furthermore, immunostaining showed that MHCII is mainly located in the microglia. Microglia are believed to be involved in antigen processing, a key cause of BCP. , minocycline (MC) treatment inhibits the activation of microglia and reduces the expression of MHCII and proinflammatory cytokines, thereby alleviating BCP and pain-related anxiety. Taken together, our study identified differentially expressed genes in the BCP process and demonstrated that the activation of microglia participates in the inflammatory response and antigen process, which may contribute to BCP.
Learn More >We hypothesized that unilateral leg pain following surgical treatment of lumbar disc herniation (LDH) is associated with an increase in the glucose metabolism of the contralateral thalamus.
Learn More >Preclinical pain research has applied state-of-the-art methods over the past 40 years to describe, characterize, and image molecules, cells, and circuits in rodents to understand the pathophysiology of chronic pain. Despite generating a plethora of novel analgesic targets, pharmaceuticals for chronic pain treatment remain largely limited to the same 6 drug classes as present 40 years ago. It is possible that 40 years of effort has brought us to the verge of a paradigm shift and an explosion of novel analgesic drug classes with remarkable safety, efficacy, and tolerability. We think it more likely that advances will not occur until we follow the description of exciting discoveries with hypothesis testing using clinically relevant preclinical animal models and ethologically relevant outcome measures, which better reflect the clinical characteristics of chronic pain syndromes. Furthermore, to be valuable, experiments using such models must be conducted to the highest levels of internal validity, rigor, and reproducibility. Efforts by funders, most recently the Helping End Addiction Long-Term by the National Institutes of Health, aim to address some of these challenges and enhance communication and collaboration between preclinical and clinical investigators. However, the greater problem is a culture that emphasizes novelty and number of publications over scientific rigor and robust replication leading to a high likelihood of false-positive results. A path forward is provided by the evolution of clinical research beginning 50 years ago that resulted in methods to reduce bias and enhance transparency and ethics of reporting, moving from case reports to randomized controlled trials to innovative study designs with a focus on rigor, generalizability, and reproducibility. We argue that culture changed in clinical science in part because powerful forces outside the peer review system, especially from federal regulators that approve new drugs and human studies committees that addressed ethical failures of earlier research, mandated change in studies within their purview. Whether an external force will affect change in peclinical pain research is unclear.
Learn More >While factors contributing to between-subjects differences in pain have been studied extensively, factors contributing to the within-subjects variability of pain reports are yet unexplored. The aim of this investigation was to assess possible associations between short-term memory and the within-subjects variability of pain reports in healthy and chronic pain patients. Healthy participants were recruited at the University of Haifa, Israel, and Fibromyalgia patients were recruited at a rheumatology department in a central hospital in Lisbon, Portugal. Following consent, both cohorts underwent the same procedures, including the digit-span test, assessing short-term memory, and the FAST procedure, assessing within-subject variability of pain intensity reports in response to experimental pain. One-hundred twenty-one healthy volunteers and 29 Fibromyalgia patients completed the study. While a significant correlation was found between the within-subjects variability and the total score of the short-term memory task (Spearman's r = 0.394, P = 0.046) in the Fibromyalgia group, a marginal correlation emerged in the healthy cohort (r = 0.174, P = 0.056). A possible interpretation of these results is that in the patients' group, at least some of the within-subjects variability of pain intensity reports might be due to error measurement derived by poorer short-term memory, rather than true fluctuations in perception.
Learn More >Morphine and other opioids are used to manage cancer-related pain; however, the role of these drugs in cancer progression remains controversial. Emerging evidence indicates that morphine can activate Toll-like receptor 4 (TLR4) and its signaling pathways, by the way the activation and expression of TLR4 can promote melanoma. In this study, we investigated the effects of morphine on the expression of TLR4 and promotion of melanoma in mice.
Learn More >The research was designed to assess the consequences of aqueous leaf extract (AILE) neuropathic pain in Wister rats and the role of the ATP-dependent potassium channel (K) as an underlying mechanism.
Learn More >Chronic pain is undertreated in people with Alzheimer's disease (AD) and better understanding of the underlying mechanisms of chronic pain in this neurodegenerative disease is essential. Neuropathic pain and AD share a significant involvement of the peripheral immune system. Therefore, we examined the development of nerve injury-induced allodynia in TASTPM (APPsweXPS1.M146V) mice and assessed monocytes/macrophages at injury site. TASTPM developed partial allodynia compared to WT at days 7, 14 and 21 days after injury, and showed complete allodynia only after treatment with naloxone methiodide, a peripheralized opioid receptor antagonist. Since macrophages are one of the sources of endogenous opioids in the periphery, we examined macrophage infiltration at injury site and observed that CD206/MHCII cells were more numerous in TASTPM than WT. Accordingly, circulating TASTPM Ly6C (classical) monocytes, which are pro-inflammatory and infiltrate at the site of injury, were less abundant than in WT. In experiments, TASTPM bone marrow-derived macrophages showed efficient phagocytosis of myelin extracts containing amyloid precursor protein, acquired CD206/MHCII phenotype, upregulated mRNA expression of proenkephalin () and accumulated enkephalins in culture media. These data suggest that in TASTPM nerve-injured mice, infiltrating macrophages which derive from circulating monocytes and may contain amyloid fragments, acquire M2-like phenotype after myelin engulfment, and release enkephalins which are likely to inhibit nociceptive neuron activity via activation of opioid receptors.
Learn More >Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) are structurally related neuropeptides that are widely expressed in vertebrate tissues. The two neuropeptides are pleiotropic and have been associated with migraine pathology. Three PACAP and VIP receptors have been described: PAC1, VPAC1, and VPAC2. The localization of these receptors in relation to VIP and PACAP in migraine-relevant structures has not previously been shown in mice. In the present study, we used fluorescence immunohistochemistry, well-characterized antibodies, confocal microscopy, and three-dimensional reconstruction to visualize the distribution of PACAP, VIP, and their receptors in the basal blood vessels (circle of Willis), trigeminal ganglion, and brain stem spinal trigeminal nucleus (SP5) of the mouse CNS. We demonstrated a dense network of circularly oriented VIP fibers on the basal blood vessels. PACAP nerve fibers were fewer in numbers compared to VIP fibers and ran along the long axis of the blood vessels, colocalized with calcitonin gene-related peptide (CGRP). The nerve fibers expressing CGRP are believed to be sensorial, with neuronal somas localized in the trigeminal ganglion and PACAP was found in a subpopulation of these CGRP-neurons. Immunostaining of the receptors revealed that only the VPAC1 receptor was present in the basal blood vessels, localized on the surface cell membrane of vascular smooth muscle cells and innervated by VIP fibers. No staining was seen for the PAC1, VPAC1, or VPAC2 receptor in the trigeminal ganglion. However, distinct PAC1 immunoreactivity was found in neurons innervated by PACAP nerve terminals located in the spinal trigeminal nucleus. These findings indicate that the effect of VIP is mediated via the VPAC1 receptor in the basal arteries. The role of PACAP in cerebral arteries is less clear. The localization of PACAP in a subpopulation of CGRP-expressing neurons in the trigeminal ganglion points toward a primary sensory function although a dendritic release cannot be excluded which could stimulate the VPAC1 receptor or the PAC1 and VPAC2 receptors on immune cells in the meninges, initiating neurogenic inflammation relevant for migraine pathology.
Learn More >Orofacial pain, in particular, chronic orofacial pain remains a great challenge in clinical practice. To better understand the underlying mechanism of disease, it is essential to apply a feasible and stable preclinical measurement of facial pain. Here, we introduced a novel electrical noxious stimulator in freely behavioral rodents and examined its validation in both naïve and chronic orofacial pain animals.
Learn More >This prospective observational study included 80 adults (>18 years) patients admitted to the intensive care unit who were unconscious (Glasgow Coma Scale [GCS] score < 9 with a motor response < 5) and receiving mechanical ventilation. A tetanic stimulation was used to assess nociception; automated pupillometry (Algiscan, ID-MED, France) was used to compute the pupillary pain index score (PPI), with a PPI > 4 considered as nociception. Concomitantly, the number of skin conductance fluctuations (NSCF) per second, measured using a Skin Conductance Algesimeter (SCA, MEDSTORM Innovation AS, Norway; > 0.27 fluctuations/sec indicating nociception), and the instantaneous Analgesia Nociception Index (iANI, MDoloris Medical Systems, France; < 50 indicating nociception) were collected. Tetanic stimulation resulted in a median pupillary dilation of 16 [6-25] % and a PPI of 5 [2-7]. According to the PPI assessment, 44 patients (55%) had nociception, whereas 23 (29%) and 18 (23%) showed nociception according to the algesimeter and iANI assessment, respectively. No significant changes in measured physiologic variables were observed after the tetanic stimulation. There were no correlations between PPI, post-stimulation iANI, and SCA-derived variables. There were no differences in PPI, iANI, and SCA variables in patients with low and normal baseline EEG power at baseline. PERSPECTIVES: Detection of nociception varies across different devices in unconscious critically ill patients. Further studies are required to understand which method to implement for analgesic administration in this patient population.
Learn More >Recurrent acute pancreatitis and chronic pancreatitis represent high morbidity diseases, which are frequently associated with chronic abdominal pain, pancreatic insufficiencies, and reduced quality of life. Currently, there are no therapies to reverse or delay disease progression, and clinical trials are needed to investigate potential interventions that would address this important gap. This conference report provides details regarding information shared during a National Institute of Diabetes and Digestive and Kidney Diseases-sponsored workshop on Clinical Trials in Pancreatitis that sought to clearly delineate the current gaps and opportunities related to the design and conduct of patient-focused trials in recurrent acute pancreatitis and chronic pancreatitis. Key stakeholders including representatives from patient advocacy organizations, physician investigators (including clinical trialists), the US Food and Drug Administration, and the National Institutes of Health convened to discuss challenges and opportunities with particular emphasis on lessons learned from trials in participants with other painful conditions, as well as the value of incorporating the patient perspective throughout all stages of trials.
Learn More >Migraine is a common neurological disorder characterized by repeated headaches of varying intensity. The prevalence and severity of migraine headaches disproportionally affects women, particularly during the postpartum period. Moreover, migraines during pregnancy have been associated with adverse maternal outcomes, including preeclampsia and postpartum stroke. However, due to the lack of a validated instrument for uniform case ascertainment on postpartum migraine headache, there is uncertainty in the reported prevalence in the literature.
Learn More >Pain is an experience of a subjective nature, interpreted in a personal way and according to an extensive palette of factors unique to each individual. Orofacial pain can be acute or chronic and it is usually the main reason for the patient to seek dental care. Pain perception varies widely among individuals. This variability is considered a mosaic of factors, which include biopsychosocial factors and genetic factors. Understanding these differences can be extremely beneficial for pain management in a personalized and more efficient way. We performed association studies to investigate phenotypes associated with genetic markers in pain-related genes in two groups of patients who received more or less anesthesia during dental treatment. The study group was comprised of 1289 individuals participating in the Dental Registry and DNA Repository Project (DRDR) of the University of Pittsburgh, with 900 participants in the group that received the most anesthesia and 389 constituting the comparison group that received less anesthesia. We tested 58 phenotypes and genotypic data of seven SNPs in genes that are associated with pain perception, pain modulation and response to drugs used in pain treatment: COMT (rs4818 and rs6269), GCH1 (rs3783641), DRD2 (rs6276), OPRM1 (rs1799971), SCN9A (rs6746030) and SCN10A (rs6795970). The analysis revealed a protective effect of rs1799971 on asthma in the total sample. rs3783641 was associated with salivary secretion disorders in females who received more anesthesia. rs1799971 was also associated with periodontitis in Whites who received less anesthesia. rs4818 was associated with disease and other tongue conditions in the group composed of Blacks who received less anesthesia. In conclusion, our study implicated variants in pain-related genes in asthma and oral phenotypes.
Learn More >Excessive pain during medical procedures is a worldwide medical problem. Most scald burns occur in children under 6, who are often undermedicated. Adjunctive Virtual Reality (VR) distraction has been shown to reduce pain in children aged 6-17, but little is known about VR analgesia in young children. This study tests whether desktop VR (VR Animal Rescue World) can reduce the just noticeable pressure pain of children aged 2-10.
Learn More >People who experience persistent pain often require help from a family member, partner, or friend. These caregivers frequently have pain but are often not included in interventions. Caregivers and care receivers who both experience pain are more likely to be socially isolated, and experience communication conflict and decreased quality of life. Interventions should target caregiving dyads to help them manage their pain together. However, there are few intervention manuals or research protocols developed to support the dyad.
Learn More >There is currently no agreed minimum dataset to inform specialist chronic pain service provision. We aimed to develop a Core Minimum Dataset (CMD) for pain services in Scotland and perform preliminary analysis to evaluate its psychometric properties in adults with chronic pain.
Learn More >Recent data indicated a high incidence of inappropriate management of neuromuscular block, with a high rate of residual paralysis and relaxant-associated postoperative complications. These data are alarming in that the available neuromuscular monitoring, as well as myorelaxants and their antagonists basically allow well tolerated management of neuromuscular blockade. In this first European Society of Anaesthesiology and Intensive Care (ESAIC) guideline on peri-operative management of neuromuscular block, we aim to present aggregated and evidence-based recommendations to assist clinicians provide best medical care and ensure patient safety. We identified three main clinical questions: Are myorelaxants necessary to facilitate tracheal intubation in adults? Does the intensity of neuromuscular blockade influence a patient's outcome in abdominal surgery? What are the strategies for the diagnosis and treatment of residual paralysis? On the basis of this, PICO (patient, intervention, comparator, outcome) questions were derived that guided a structured literature search. A stepwise approach was used to reduce the number of trials of the initial research (n = 24 000) to the finally relevant clinical studies (n = 88). GRADE methodology (Grading of Recommendations, Assessment, Development and Evaluation) was used for formulating the recommendations based on the findings of the included studies in conjunction with their methodological quality. A two-step Delphi process was used to determine the agreement of the panel members with the recommendations: R1 We recommend using a muscle relaxant to facilitate tracheal intubation (1A). R2 We recommend the use of muscle relaxants to reduce pharyngeal and/or laryngeal injury following endotracheal intubation (1C). R3 We recommend the use of a fast-acting muscle relaxant for rapid sequence induction intubation (RSII) such as succinylcholine 1 mg kg-1 or rocuronium 0.9 to 1.2 mg kg-1 (1B). R4 We recommend deepening neuromuscular blockade if surgical conditions need to be improved (1B). R5 There is insufficient evidence to recommend deep neuromuscular blockade in general to reduce postoperative pain or decrease the incidence of peri-operative complications. (2C). R6 We recommend the use of ulnar nerve stimulation and quantitative neuromuscular monitoring at the adductor pollicis muscle to exclude residual paralysis (1B). R7 We recommend using sugammadex to antagonise deep, moderate and shallow neuromuscular blockade induced by aminosteroidal agents (rocuronium, vecuronium) (1A). R8 We recommend advanced spontaneous recovery (i.e. TOF ratio >0.2) before starting neostigmine-based reversal and to continue quantitative monitoring of neuromuscular blockade until a TOF ratio of more than 0.9 has been attained. (1C).
Learn More >Due to the inherent subjectivity of pain, it is difficult to make accurate judgments of pain in others. Research has found discrepancies between the ways in which perceived "objective" (e.g., medical evidence of injury) and "subjective" information (e.g., self-report) influence judgments of pain. This study aims to explore which potential cues (depictions of sensory input, brain activation, self-reported pain, and facial expressions) participants are most influenced by when evaluating pain in others.
Learn More >The pathogenesis of neuropathic pain (NP) has not been fully elucidated. Gene changes in dorsal root ganglia (DRG) may contribute to the development of NP. Circular RNAs (circRNAs) are a class of endogenous noncoding RNAs that form covalently closed loop structures and are crucial for genetic and epigenetic regulation. However, little is known about circRNA changes in DRG neurons after peripheral nerve injury.
Learn More >At this centenary of the British Journal of Anaesthesia (BJA) in 2023, six of its 12 editors/editors-in-chief detail developments over the decades that have led to the BJA becoming a high-impact international scientific journal. As a charity, the BJA supports academic research and training in anaesthesia, critical care, and pain medicine including funding of research grants and postgraduate education. Building on this foundation, the BJA continues to innovate as it aims to become fully electronic, expand into open access publishing, and increase the diversity of its editorial board.
Learn More >Appropriate analgesia is a crucial part of rodent postoperative and postprocedural pain. Providing appropriate analgesia is an ethical obligation, a regulatory requirement, and an essential element of obtaining quality scientific results and conducting reproducible data. Meeting these requirements is facilitated by practical, efficient and safe delivery methods for providing analgesia. Over the last decade, long-acting analgesics have gained widespread use in research animal medicine to avoid or treat postoperative or postprocedural pain while minimizing handling-related time and stress. Long-acting formulations of analgesics suitable for rodents are available for opioids, NSAIDs, and local anesthetics. The goal of this review is to summarize the currently available long-acting formulations of analgesics for rodents and to provide recommendations to veterinarians and researchers regarding their use.
Learn More >To describe the clinical course and prognosis of pediatric idiopathic intracranial hypertension (IIH) and examine the preferred management setting. IIH is characterized by increased intracranial pressure and is often associated with headaches and visual complaints. IIH is a preventable cause of vision loss in children. Hence, a rapid diagnosis followed by prompt treatment and follow-up is essential. However, standardization of the management of IIH in the pediatric population is not well established. Computerized medical charts of all 82 pediatric (< 18 years) patients diagnosed with IIH between 2007 and 2018 in the metropolitan area of Jerusalem were reviewed. Comparison was made between children followed in a multidisciplinary clinic in tertiary centers and those followed elsewhere. Detailed demographic and clinical data, as well as data regarding the follow-up setting and clinical course of the disease, were collected and analyzed. Recurrent IIH-related hospital returns were selected as a measurable marker for the uncontrolled disease. Recurrent IIH-related hospital return rate was significantly lower and occurred later among children followed by multidisciplinary teams compared to individual experts. Follow-up in multidisciplinary clinics improve the quality of life, and financial burden and may prevent permanent visual impairment in children with IIH.
Learn More >Assessing family supportive responses to pain behaviors is paramount, as these may help or hinder chronic pain (CP) adjustment. Current self-report measures of pain-specific family supportive dynamics are scarce, covering a limited range of responses. To address this gap, this paper aimed at the psychometric validation of a (revised) novel measure – the Informal Social Support for Autonomy and Dependence in Pain Inventory (ISSADI-PAIN). Three-hundred and three adults participated in this study (53.3% women; M=49.31), 53.5% with current CP, 20.1% with acute pain (AP) in the previous week and 26.4% with no current pain. All participants completed the revised ISSADI-PAIN. Participants reporting AP/CP in the previous week also filled out measures of pain coping/outcomes. Exploratory and confirmatory factor analyzes supported a 3-factor structure: Perceived Promotion of Dependence (PPD; 5 items; α=.82), Perceived Promotion of Autonomy-Emotional (PPA-Emot; 3 items; α=.78), PPA-instrumental (PPA-Inst; 3 items; α=.82). Higher PPD was associated with higher AP disability and less wellness-focused coping; higher PPA-Emot was associated with more wellness-focused CP coping; PPA-Inst was associated with better/worse AP/CP outcomes and more frequent use of wellness-focused CP coping. Men with AP reported more PPD than women. The revised ISSADI-PAIN is an innovative, valid, and reliable measure of relevant functions of pain-related social support, which may influence pain persistence and adaptation. Perspective: This article presents a novel self-report measure (ISSADI-PAIN) that assesses family support for functional autonomy and dependence in pain contexts. This measure may contribute to further research on the complexities of family supportive dynamics surrounding individuals with AP/CP, clarifying their role on pain persistence and adaptation processes.
Learn More >Osteoarthritis is a common and severe, multifactorial disease with a well-established genetic component. However, little is known about how genetics affect disease progression, and thereby the need for joint placement. Therefore, we aimed to investigate whether the genetic associations of knee and hip osteoarthritis differ between patients treated with joint replacement and patients without joint replacement.
Learn More >Endometriosis, a benign gynecologic and chronic inflammatory disease, is defined by the presence of endometrial tissue outside the uterus characterized mainly by pelvic pain and infertility. Because endometriosis affects approximately 10% of females, it represents a significant socioeconomic burden worldwide having tremendous impact on daily quality of life. Accurate and prompt diagnosis is crucial for the management of this debilitating disorder. Unfortunately, diagnosis is typically delayed to lack of specific symptoms and readily accessible biomarkers. Although histopathologic examination remains the current gold standard, this approach is highly invasive and not applicable for early screening. Recent work has focused on the identification of reliable biomarkers including immunologic, ie, immune cells, antibodies and cytokines, as well as genetic and biochemical markers, ie, microRNAs, lncRNAs, circulating and mitochondrial nucleic acids, along with some hormones, glycoproteins and signaling molecules. Confirmatory research studies are, however, needed to more fully establish these markers in the diagnosis, progression and staging of these endometrial lesions.
Learn More >Amputees commonly feel an intermittent tingling, piercing, or burning sensation in the region of the missing portion of the amputated limb, a phenomenon known as phantom limb pain. Current treatment modalities include medications, mirror therapy, transcutaneous electrical nerve stimulation, and more recently neuromodulation through spinal cord stimulation and dorsal root ganglion (DRG) stimulation.
Learn More >First-line medications for the treatment of painful diabetic neuropathy (PDN) are associated with a substantial rate of discontinuation due to adverse effects or insufficient efficacy. Neuromodulation techniques have been used for PDN, but a comprehensive review of the literature that incorporates several distinct device categories has yet to be undertaken.
Learn More >The Avoidance-Endurance Model distinguishes between subgroups of low back pain (LBP) patients with three maladaptive styles of coping with pain: fear-avoidance (FAR), distress-endurance (DER), eustress-endurance (EER), and one adaptive coping style (AR). This study aimed to compare the quantity of patients' perceived psychosocial stressors and coping resources across these subgroups.
Learn More >The sympathetic nervous system (SNS) is suggested to be involved in some forms of pain, but the mechanisms of which are incompletely known. Moreover, there is a lack of information on the regulatory role of the SNS on macrophages in sensory ganglion, which plays an important role in pain development. The present study aims to investigate the effects of the SNS on orofacial inflammatory pain and examine, if any, how the SNS influences trigeminal ganglion (TG) macrophage responses.
Learn More >Persistent pain (PP) and long-term conditions are all associated with psychological well-being. Less is known about their associations with reduced psychological well-being when co-occurring. We investigated how PP and long-term physical and mental conditions relate to psychological well-being when occurring together.
Learn More >Treatment effect of current pharmacotherapies for migraine is unsatisfying. Discovering new anti-migraine natural products and nutraceuticals from large collections of Chinese medicine classical literature may assist to address this gap. We conducted a comprehensive search in the (version 5.0) to obtain migraine-related citations, then screened and scored these citations to identify clinical management of migraine using oral herbal medicine in history. Information of formulae, herbs and symptoms were further extracted. After standardisation, these data were analysed using frequency analysis and the Apriori algorithm. Anti-migraine effects and mechanisms of actions of the main herbs and formula were summarised. Among 614 eligible citations, the most frequently used formula was (CXCTS), and the most frequently used herb was . Dietary medicinal herbs including , , , and were identified. Strong associations were constructed among the herb ingredients of CXCTS formula. Symptoms of chronic duration and unilateral headache were closely related with herbs of , , , and . Symptoms of vomiting and nausea were specifically related to herbs of and . The herb ingredients of CXCTS which presented anti-migraine effects with reliable evidence of anti-migraine actions can be selected as potential drug discovery candidates, while dietary medicinal herbs including , , , , , and can be further explored as nutraceuticals for migraine.
Learn More >Spinal cord injury (SCI) is a severe disease with motor and sensory function being destroyed, which leads to a poor prognosis and a serious financial burden. It is urgent to figure out the molecular and pathological mechanisms of SCI to develop feasible therapeutic strategies. This article aims to review documents focused on gene expression in SCI and summarize research hotspots and the development process in this field.
Learn More >Veratramine may have a potential therapeutic effect for diabetic peripheral neuropathy (DPN).
Learn More >The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) are used worldwide in adults. Until now, no adaptation for use in children has been proposed.
Learn More >Dental pulpitis often induces severe pain, and the molecular immune response is remarkable in both peripheral and central nervous system. Accumulating evidence indicates that activated microglia in the medullary dorsal horn (MDH) contribute to dental pulpitis induced pain. The P2X7 receptor plays an important role in driving pain and inflammatory processes, and its downstream target hypoxia-induced factor-1α (HIF-1α) has a crucial role in maintaining inflammation. However, the relationship between P2X7 and HIF-1α in dental inflammatory pain remains unclear. This study demonstrated that the degree of inflammation in the dental pulp tissue became more severe in a time-dependent manner by establishing a rat dental pulpitis model pulp exposure. Meanwhile, the expression of P2X7, HIF-1α, IL-1β, and IL-18 in the MDH increased most on the seventh day when the pain threshold was the lowest in the dental pulpitis model. Furthermore, lipopolysaccharides (LPS) increased P2X7-mediated HIF-1α expression in microglia. Notably, the suppression of P2X7 caused less IL-1β and IL-18 release and lower HIF-1α expression, and P2X7 antagonist Brilliant Blue G (BBG) could alleviate pain behaviors of the dental pulpitis rats. In conclusion, our results provide further evidence that P2X7 is a key molecule, which regulates HIF-1α expression and inflammation in dental pulpitis-induced pain.
Learn More >Opioid-reduced anesthesia may accelerate postoperative rehabilitation by reducing opioid-related side effects. The objective was to investigate the feasibility of opioid-reduced general anesthesia based on esketamine and to observe postoperative nausea and vomiting (PONV), postoperative pain, hemodynamics and other adverse reactions in gynecological day surgery compared with the traditional opioid-based anesthesia program.
Learn More >To contextualize migraine as the most common primary headache disorder in relation to other chronic primary pain and non-pain functional somatic and mental conditions.
Learn More >This study aimed to investigate how opioids affect phagocytosis and microglial nitrite and nitric oxide synthase (iNOS) production during inflammation.
Learn More >Painful diabetic polyneuropathy is one of the most common disabling problems worldwide. We aimed to determine if a perineural injection of hypertonic saline compared with foot acupoints decreased the neuropathic pain score in patients with diabetes. Patients were assigned to receive either perineural or acupoints injection of hypertonic saline 5% in their feet for three weekly sessions. Douleur Neuropathique 4 (DN4) questionnaire for neuropathic pain was assessed. Both groups observed a significant reduction of the DN4 score throughout 8 weeks of follow-up. Both perineural and acupoints hypertonic saline injections of the foot could improve neuropathic pain in patients with diabetes.
Learn More >to assess evidence available in the literature about the use of sedation and analgesia for intratracheal intubation of newborns.
Learn More >Spinal cord stimulation (SCS) technology has been recently approved by the US Food and Drug Administration (FDA) for painful diabetic neuropathy (PDN). The treatment involves surgical implantation of electrodes and a power source that delivers electrical current to the spinal cord. This treatment decreases the perception of pain in many chronic pain conditions, such as PDN. The number of patients with PDN treated with SCS and the amount of data describing their outcomes is expected to increase given four factors: (1) the large number of patients with this diagnosis, (2) the poor results that have been obtained for pain relief with pharmacotherapy and noninvasive non-pharmacotherapy, (3) the results to date with investigational SCS technology, and (4) the recent FDA approval of systems that deliver this treatment. Whereas traditional SCS replaces pain with paresthesias, a new form of SCS, called high-frequency 10-kHz SCS, first used for pain in 2015, can relieve PDN pain without causing paresthesias, although not all patients experience pain relief by SCS. This article describes (1) an overview of SCS technology, (2) the use of SCS for diseases other than diabetes, (3) the use of SCS for PDN, (4) a comparison of high-frequency 10-kHz and traditional SCS for PDN, (5) other SCS technology for PDN, (6) deployment of SCS systems, (7) barriers to the use of SCS for PDN, (8) risks of SCS technology, (9) current recommendations for using SCS for PDN, and (10) future developments in SCS.
Learn More >Mounting evidence suggests that individuals who engage in nonsuicidal self-injury (NSSI) have lower pain sensitivity (e.g., pain thresholds and tolerances) than individuals without a history of NSSI. However, research has been largely cross-sectional, so it is unclear whether low pain sensitivity may increase risk for NSSI, or whether NSSI diminishes pain sensitivity over time. In the present study, the relations among NSSI frequency, versatility (number of NSSI methods), pain threshold, and pain tolerance were examined using a longitudinal research design. Participants included 156 undergraduate students at a large university (87% female; Mage = 19.79) with a recent history of NSSI. Participants reported on their NSSI engagement and completed a cold pressor task in a baseline session, as well as at one year follow-up. Eight regression models were run to examine the nature of the association between the two pain measures (i.e., pain threshold and tolerance) and the two NSSI measures (i.e., frequency and versatility). Pain tolerance and pain threshold predicted NSSI versatility over time, but NSSI frequency and versatility did not predict pain threshold or tolerance over time. Results suggest that low pain sensitivity may be a risk factor for severe NSSI engagement.
Learn More >HER-MES was the first head-to-head, phase 4 trial to assess the tolerability and effectiveness of erenumab against standard of care treatment (topiramate). This post hoc analysis compared the efficacy of erenumab with topiramate in patients who completed the trial on study medication.
Learn More >Pitavastatin is a competitive HMG-CoA reductase inhibitor for lowering of cholesterol level and low density lipoprotein cholesterol. This study was designed to evaluate the effect of pitavastatin in neuropathic pain induced by partial sciatic nerve ligation along with neuronal changes in Wister rats.
Learn More >Migraine is a worldwide disabling chronic brain disorder, some studies suggest acupuncture-related therapy plays an important role in raising efficiency rates and reducing migraine attacks. However, clinical trials comparing the efficacy of different interventions for migraine are limited and controversial. This network meta-analysis (NMA) was performed to review all randomized controlled trials (RCTs) comparing the effects of acupuncture-related therapy for migraine.
Learn More >Prescribing opioids upon discharge after surgery is common practice; however, there are many inherent risks including dependency, diversion, and medical complications. Our prospective pre- and post-intervention study investigates the effect of a standardized analgesic prescription on the quantity of opioids prescribed and patients' level of pain and satisfaction with pain control in the early post-operative period.
Learn More >Dorsal root ganglion stimulation (DRGS) is a neurostimulation therapy used to manage chronic pain that does not respond to conventional therapies. Unfortunately, not all patients receive sufficient pain relief from DRGS, leaving them with few other treatment options. Presently, our understanding of the mechanisms of action of DRGS is incomplete, preventing us from determining why some patients do not receive analgesia from the therapy. One hypothesis suggests that DRGS augments the filtering of action potentials (APs) at the T-junction of nociceptive C-neurons. To test this hypothesis, we utilized a computational modeling approach in which we developed a population of one thousand biophysically distinct C-neuron models which each produced electrophysiological characteristics (e.g., AP height, AP duration) reported in previous experimental studies. We used this population of model C-neurons to study how morphological and electrophysiological characteristics affected the propagation of APs through the T-junction. We found that trains of APs can propagate through the T-junction in the orthodromic direction at a higher frequency than in the antidromic direction due to the decrease in axonal diameter from the peripheral to spinal axon. Including slow outward conductances in the axonal compartments near the T-junction reduced following frequencies to ranges measured experimentally. We next used the population of C-neuron models to investigate how DRGS affected the orthodromic propagation of APs through the T-junction. Our data suggest that suprathreshold DRGS augmented the filtering of APs at the T-junction of some model C-neurons while increasing the activity of other model C-neurons. However, the stimulus pulse amplitudes required to induce activity in C-neurons (i.e., several mA) fell outside the range of stimulation pulse amplitudes used clinically (i.e., typically ≤1 mA). Furthermore, our data suggest that somatic GABA currents activated directly or indirectly by the DRGS pulse may produce diverse effects on orthodromic AP propagation in C-neurons. These data suggest DRGS may produce differential effects across a population of C-neurons and indicate that understanding how inherent biological variability affects a neuron's response to therapeutic electrical stimulation may be helpful in understanding its mechanisms of action.
Learn More >Older adults with chronic neck pain (CNP) demonstrate impaired postural control. The Balance Evaluation Systems Test (BESTest) is used to assess systems underlying postural control impairments, but its use in CNP has not been reported. This study assessed whether the BESTest can identify postural control impairments in CNP as well as the level of BESTest item difficulty by Rasch analysis.
Learn More >Diabetic neuropathic pain (DNP) is a common, complex, and severe complication of diabetes. It can lead to increased mortality, lower-limb amputations, and distressing neuropathic symptoms. Available therapies for DNP are broad-spectrum analgesics, related to various side effects. Transient receptor potential vanilloid-1 (TRPV1) is widely expressed within the peripheral and central nervous systems and plays an essential role in pain perception and regulation. Both TRPV1 agonists and antagonists could reduce the sensitivity to nociception. Some exhibit blood glucose homeostasis regulates function by influencing insulin secretion and receptor sensitivity. Since TRPV1 has exhibited the unique advantages of simultaneously managing blood sugar and pain, developing new TRPV1 channel modulators for diabetes-related pain syndrome is a promising alternative to conventional therapy. In this review, the role of TRPV1 in the pathogenesis of DNP has been described and challenges of TRPV1 modulators have been explored to be a new therapy for DNP.
Learn More >This study observed the cutaneous analgesic effect of adrenergic agonists when combined with lidocaine. We aimed at the usefulness of 4 adrenergic agonists and epinephrine as analgesics or as tools to prolong the effect of local anesthetics using a model of cutaneous trunci muscle reflex (pinprick pain) in rats. We showed that subcutaneous 4 adrenergic agonists and epinephrine, as well as the local anesthetic bupivacaine and lidocaine, developed a concentration-dependent cutaneous analgesia. The rank order of the efficacy of different compounds (ED ; median effective dose) was epinephrine [0.013 (0.012 – 0.014) μmol] > oxymetazoline [0.25 (0.22 – 0.28) μmol] > naphazoline [0.42 (0.34 – 0.53) μmol] = bupivacaine [0.43 (0.37 – 0.50) μmol] > xylometazoline [1.34 (1.25 – 1.45) μmol] > lidocaine [5.86 (5.11 – 6.72) μmol] > tetrahydrozoline [6.76 (6.21 – 7.36) μmol]. The duration of full recovery caused by tetrahydrozoline, oxymetazoline, or xylometazoline was greater (P<0.01) than that induced via epinephrine, bupivacaine, lidocaine, or naphazoline at equianesthetic doses (ED , ED , and ED ). Co-administration of lidocaine (ED ) with 4 adrenergic agonists or epinephrine enhanced the cutaneous analgesic effect. We observed that 4 adrenergic agonists and epinephrine induce analgesia by themselves, and such an effect has a longer duration than local anesthetics. Co-administration of lidocaine with the adrenergic agonist enhances the analgesic effect, and the cutaneous analgesic effect of lidocaine plus naphazoline (or oxymetazoline) is greater than that of lidocaine plus epinephrine.
Learn More >The endocannabinoid 2-Arachidonyl glycerol (2-AG) exerts dose-related anti-nociceptive effects, which are potentiated by the related but inactive 2-palmitoyl glycerol (2-PG) and 2-linoleoyl glycerol (2-LG). This potentiation of analgesia and other in vivo measures was described as the "entourage effect". We investigated this effect on TRPV1 signalling in cultured dorsal root ganglion (DRG) nociceptors.
Learn More >Knee osteoarthritis (KOA) is a degenerative disease with inflammation, becoming persistent as it progresses, resulting in reduced quality of life. Exercise is the recommended treatment for KOA; however, the extent of pain reduction with exercise is heterogeneous and the prognostic implications of baseline factors in patients undergoing exercise are still unknown. This study examined the association between the response to exercise therapy and clinical outcomes, radiologic severity, and pain sensitization, and investigated the optimal predictive value for the effectiveness of exercise.
Learn More >Glial cells are involved in the analgesic effect of electroacupuncture (EA) in rats with chronic neurological pain. The objective of this study was to observe the role of neuronal-glial interaction and glutamate (Glu) transporters in EA-induced acute neck pain relief in rats.
Learn More >Migraine is a common neurologic disorder with clinical phenotypes encompassing a variety of symptoms which all contribute to the burden felt by patients. In addition to negative impacts on a patient's quality of life, migraine has both direct medical costs and indirect costs related to missed work and decreased productivity that affect individuals as well as society at large. Unfortunately, migraine diagnoses are often missed, and many patients do not receive appropriate treatment. Primary care providers are in a key position to provide timely diagnosis and effectively manage migraine for many patients. This review aims to be a guide for improving migraine management in the primary care setting by providing strategies to overcome common challenges in migraine diagnosis; summarizing current knowledge on the mechanism of action, efficacy, and safety of calcitonin gene-related peptide (CGRP) pathway-targeting therapies; and reviewing approaches to incorporate traditional and emerging treatment options into a patient-centric migraine management strategy.
Learn More >Extensive research has demonstrated that music and touch can separately attenuate perceived pain intensity. However, little research has investigated how auditory and tactile stimulation can synergistically enhance pain attenuation by music. In the current study, we investigated whether tactile stimulation can enhance music-induced analgesia for noxious force stimulation on the fingertip.
Learn More >Cognitive Behaviour Therapy (CBT)-based programmes for chronic pain are often conducted in groups, most likely for time and cost efficiencies. However, there has been very little investigation of the role that the group itself, and particularly the processes occurring within the group, may play in individual outcomes. The objective of this study was to explore whether social group processes were relevant to key treatment outcomes of group CBT for chronic pain.
Learn More >According to a recent survey of patients with the autoimmune disease primary Sjögren's syndrome (pSS), dry eye symptoms are present in 95-98% of pSS patients. As one of the most disabling symptoms mentioned by pSS patients, dry eyes have demonstrable effects on quality of their life, leading to eye dryness, itching, and pain, with some patients describing as a recurrent sensation of sand or gravel in the eyes. The symptoms are matched only in prevalence by dry mouth and chronic fatigue. In contrast to the prevalence of dry eye symptoms in pSS and their burden on pSS patients, our comprehension of dry eye disease development is minimal; specifically how function of the tear-fluid producing gland the lacrimal gland (LG), manifests. The comparison becomes stronger again when we consider what we know about dysfunction of the salivary gland (SG) in pSS, for example the appreciation of the transcriptome of 'innately activated' B cells invading the SG, their complicity in formation of lymphoepithelial lesions, and the ability of the SG epithelium to actively contribute to the inflammatory milieu. The exploration of ultrasound imaging as an additional modality to garner information about SG dysfunction in pSS has opened many doors for non-invasive, repeatable imaging in pSS. Here we summarise SG histology and ultrasound phenotype briefly and then juxtapose this with available studies examining LG pathology and ultrasound, and our understanding of LG dysfunction in pSS.
Learn More >Electroencephalographic (EEG) alterations have been demonstrated in acute, chronic, and experimentally induced musculoskeletal (MSK) pain conditions. However, there is no cumulative evidence on the associated EEG characteristics differentiating acute, chronic, and experimentally induced musculoskeletal pain states, especially compared to healthy controls. The present systematic review was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines (PRISMA) to review and summarize available evidence for cortical brain activity and connectivity alterations in acute, chronic, and experimentally induced MSK pain states. Five electronic databases were systematically searched from their inception to 2022. A total of 3471 articles were screened, and 26 full articles (five studies on chronic pain and 21 studies on experimentally induced pain) were included for the final synthesis. Using the Downs and Black risk of assessment tool, 92% of the studies were assessed as low to moderate quality. The review identified a 'very low' level of evidence for the changes in EEG and subjective outcome measures for both chronic and experimentally induced MSK pain based on the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria. Overall, the findings of this review indicate a trend toward decreased alpha and beta EEG power in evoked chronic clinical pain conditions and increased theta and alpha power in resting-state EEG recorded from chronic MSK pain conditions. EEG characteristics are unclear under experimentally induced pain conditions.
Learn More >Gastrointestinal immune-related adverse events are frequently caused by immune checkpoint inhibitors (ICIs) and often require interruption of cancer treatment. Compared with ICI colitis and enteritis, limited information exists about ICI gastritis. This study characterized clinical features and treatment outcomes of ICI gastritis.
Learn More >The 28-joint disease activity score (DAS28) is a widely used measure to assess disease activity in rheumatoid arthritis (RA). The DAS28-P index, a derived proportion of the patient-reported components (joint tenderness and patient global assessment) within the DAS28, has been utilized as a discriminatory measure of non-inflammatory pain mechanisms in RA. This study aimed to evaluate the use of the DAS28-P index as a predictor of treatment response in early RA.
Learn More >Pain affects everyone hence one can argue that it is in each individual's interest to understand pain in order to hold correct and adaptive beliefs and attitudes about pain. In addition, chronic pain is reaching pandemic proportions and it is now well known that people living with chronic pain have a reduced life expectancy. To address and to prevent the growth of this public health disaster, we must start looking beyond adulthood. How children view pain has an impact on their behavioral coping responses which in turn predict persistent pain early in the lifespan. In addition, children who suffer from chronic pain and who are not (properly) treated for it before adolescence have an increased risk of having chronic pain during their adult life. Explaining pain to children and youth may have a tremendous impact not only on the individual child suffering from chronic pain but also on society, since the key to stop the pain pandemic may well lie in the first two decades of life. In order to facilitate the acquisition of adaptive behavioral coping responses, pain education aims to shift people's view on pain from being an apparent threat towards being a compelling perceptual experience generated by the brain that will only arise whenever the conceivable proof of danger to the body is greater than the conceivable proof of safety to the body. Nowadays a lot of pain education material is available for adults, but it is not adapted to children's developmental stage and therefore little or not suitable for them. An overview of the state-of-the-art pain education material for children and youth is provided here, along with its current and future areas of application as well as challenges to its development and delivery. Research on pediatric pain education is still in its infancy and many questions remain to be answered within this emerging field of investigation.
Learn More >Oxygen is one of the most commonly used drugs by anesthesiologists. The World Health Organization (WHO) gave recommendations regarding perioperative oxygen administration, but the practice of oxygen use in anesthesia, critical emergency, and intensive care medicine remains unclear.
Learn More >Chronic pain is challenging to treat due to the limited therapeutic options and adverse side-effects of therapies. Astrocytes are the most abundant glial cells in the central nervous system and play important roles in different pathological conditions, including chronic pain. Astrocytes regulate nociceptive synaptic transmission and network function via neuron-glia and glia-glia interactions to exaggerate pain signals under chronic pain conditions. It is also becoming clear that astrocytes play active roles in brain regions important for the emotional and memory-related aspects of chronic pain. Therefore, this review presents our current understanding of the roles of astrocytes in chronic pain, how they regulate nociceptive responses, and their cellular and molecular mechanisms of action.
Learn More >Previous research suggests that individuals with post-traumatic stress disorder (PTSD) have higher risk of chronic pain symptoms. It remains unknown whether risk of chronic pain symptoms occurs in the offspring of parents with PTSD. This study aimed to explore the risk of chronic pain conditions and depression in the offspring of parents with PTSD.
Learn More >The perioperative period is a data-rich environment with potential for innovation through digital health tools and predictive analytics to optimize patients' health with targeted prehabilitation. Although some risk factors for postoperative pain following pediatric surgery are already known, the systematic use of preoperative information to guide personalized interventions is not yet widespread in clinical practice.
Learn More >Trigeminal neuralgia is a sudden, unilateral, stabbing pain in the distribution of one or more branches of the fifth cranial nerve, with an overall prevalence ranging between 0.03 and 0.3%. While conservative treatments may offer temporary relief, many patients experience chronic headaches associated with their neuralgia. Invasive treatments are available for patients with intractable neuralgia; however, they may cause permanent tissue damage and often do not provide relief. This article examines pulsed radiofrequency (PRF) ablation (RFA) of the trigeminal nerve as a minimally invasive procedure that offers a promising alternative to invasive procedures for relief of trigeminal neuralgia while minimizing tissue damage.
Learn More >Transient receptor potential vanilloid type 4 (TRPV4) channels are Ca-permeable non-selective cation channels which mediate a wide range of physiological functions and are activated and modulated by a diverse array of stimuli. One of this ion channel's least discussed functions is in relation to the generation and maintenance of certain pain sensations. However, in the two decades which have elapsed since the identification of this ion channel, considerable data has emerged concerning its function in mediating pain sensations. TRPV4 is a mediator of mechanical hyperalgesia in the various contexts in which a mechanical stimulus, comprising trauma (at the macro-level) or discrete extracellular pressure or stress (at the micro-level), results in pain. TRPV4 is also recognised as constituting an essential component in mediating inflammatory pain. It also plays a role in relation to many forms of neuropathic-type pain, where it functions in mediating mechanical allodynia and hyperalgesia.Here, we review the role of TRPV4 in mediating pain sensations.
Learn More >Osteoarthritis is common in the aging dog and is associated with chronic pain and impaired mobility. The main objective of this study was to determine whether low-level laser therapy (LLLT) would increase physical activity in dogs with osteoarthritis.
Learn More >Complex Regional Pain Syndrome (CRPS) is a chronic debilitating neuropathic pain condition characterized by autonomic and inflammatory features that typically occurs after a traumatic event. Spinal cord stimulation (SCS) has been shown to be effective in the treatment of chronic CRPS refractory to conventional treatment modalities. The collective evidence of novel parameters of SCS for treating CRPS has not been characterized extensively.
Learn More >We examined long-term health outcomes associated with new persistent opioid use after surgery and hypothesized that patients with new persistent opioid use would have poorer overall health outcomes compared to those who did not develop new persistent opioid use after surgery.
Learn More >Approximately 60% of female migraineurs experience menstrual migraine (MM). Whether MM is a distinct clinical entity with more severe migraine attacks and a worse prognosis than nonmenstrual migraine (nMM) is still under debate. We conducted a systematic review and meta-analysis to investigate clinical differences between MM and nMM patients.
Learn More >Virtual reality (VR) is emerging as a new technology in the healthcare sector. It has been shown to enhance the patient's experience and satisfaction in various settings. This review aims to give a brief description of the use of VR and establish validity of its applications to improve the patient's pathway through surgery.
Learn More >Migraine is a worldwide epidemic neurological disorder that has a significant influence on the quality of life. Migraine attacks are considered to be related to a calcitonin gene-related peptide (CGRP) signaling molecule, and anti-CGRP medications are used to abort and prevent migraine attacks. Erenumab, a monoclonal antibody that targets the CGRP receptor, is the first migraine preventive medication approved by the US Food and Drug Administration. In the present study, we evaluate the efficacy and safety of erenumab.
Learn More >Persistent low back pain (PLBP) is the biggest global cause of disability. Persons with PLBP experience biographic disruption and existential crisis. Guidelines recommend a biopsychosocial approach to management, with the emphasis on coping strategies.
Learn More >Postoperative pain after video-assisted thoracoscopic surgery (VATS) is common in lung cancer patients, and it is unclear whether cancer itself participates in pain regulation. Programmed cell death ligand-1 (PD-L1) expressed by tumors may be analgesic. Our study aimed to detect the association between PD-L1 and acute postoperative pain.
Learn More >Improving movement control might be a promising treatment goal during chronic non-specific low back pain (CLBP) rehabilitation. The objective of the study is to evaluate the effect of a single bout of game-based real-time feedback intervention on trunk movement in patients with CLBP.
Learn More >Osteoarthritis (OA) is a prevalent articular disease mainly characterized by extracellular matrix degradation, apoptosis, and inflammation, which lead to cartilage destruction and abnormal bone metabolism. With undesirable side effects, current limited symptomatic treatments are aimed at relieving pain and improving joint mobility in patients with OA. Intra-articular (IA) hyaluronic acid (HA) injection, as a nonsurgical therapy, is commonly used in the clinical management of knee OA, but the efficacy of this therapeutic option remains controversial. Ebselen has tremendous pharmacological importance for some diseases due to its antioxidant, antiapoptotic, and anti-inflammatory features. However, there is no research examining the therapeutic effect of Ebselen in OA using the rat OA model. Therefore, we aimed to investigate the therapeutic effect of Ebselen on cartilage degeneration and its role in bone morphogenetic protein 2 (BMP2) and nuclear factor kappa B (NF-κB) signaling in the molecular pathogenesis of OA. We induced a knee OA model in rats with an IA injection of monosodium-iodoacetate (MIA). After the treatment of Ebselen, we evaluated its chondroprotective effects by morphological, histopathological, and immunohistochemical methods and an enzyme-linked immunosorbent assay. We report for the first time that Ebselen treatment alleviated articular cartilage degeneration in the rat knee OA model and reduced MIA-induced BMP2 and NF-κB expressions. In addition, our results unveiled that Ebselen decreased IL-β and IL-6 levels but did not affect COMP levels in the rat serum. Ebselen could be a promising therapeutic drug for the prevention and treatment of OA by alleviating cartilage degeneration and regulating BMP2 and NF-κB expressions.
Learn More >Patients and healthcare practitioners are increasingly interested in using cannabis and cannabinoids to address unmet clinical needs. Although we have clinical evidence on the medical use of cannabinoids, a significant portion of the data is not based on randomized clinical trials, which are considered the gold standard in clinical research. We have reviewed the registered clinical trials on cannabis and cannabinoids for therapeutic or drug development purposes to underline the past and current attempts to generate robust clinical evidence and identify existing knowledge gaps.
Learn More >Lumbar disc herniation (LDH) is a global issue associated with potentially debilitating long-term consequences, including chronic low back pain (LBP). Short-term outcomes (< 2 years) of LDH patients have been extensively studied and demonstrate improvements in back and leg pain for both operative and conservative management. However, these improvements may not be sustained long-term (>2 years); LDH patients may develop recurrent disc herniations, progressive degenerative disc disease, and LBP regardless of management strategy. Therefore, our objective is to determine the prevalence of chronic LBP after LDH, understand the relationship between LDH and chronic LBP, and investigate the relationship between radiological findings and postoperative pain outcomes.
Learn More >Migraine and depression often coexist and constitute an important clinical problem. Both disorders are associated with the necessity of chronic treatment, and their mutual coexistence contributes to the phenomenon of drug resistance. Influencing the functioning of patients, they also cause numerous social consequences – affecting the quality of life and achievement of personal goals of patients. This review presents factors that may explain the common pathomechanisms of depression and migraine. Structural and functional disturbances of the central nervous system (CNS), disturbances in the neurotransmitter systems, inflammatory theories, hormonal disturbances, as well as a possible genetic basis were taken into account. Due to the fact that both depression and migraine have a multifactorial etiology and at the present stage of scientific research it is difficult to clearly determine which factor is the most important, such a broad overview has been presented. It is also difficult to determine which of the above-mentioned factors, well documented in international studies, only coexist, and which of them may have a cause-and-effect relationship in the described disorders. Further research into the comorbidity and causes of migraine and depression seems to be worth considering.
Learn More >The present study investigated the involvement of mediodorsal thalamic (MD) GABA-A receptors in cetirizine/morphine-induced anti-allodynia using a rat model of neuropathic pain. To assess the importance of the prefrontal cortex (PFC) for chronic pain processing, its expression level changes of glial fibrillary acidic protein (GFAP) were measured following drug treatments. Each animal was subjected to chronic constriction of the sciatic nerve surgery simultaneously with the MD cannulation under stereotaxic surgery. The results showed that the administration of morphine (3-5mg/kg) or cetirizine (1-3mg/kg) produced significant analgesia in neuropathic rats. Systemic administration of cetirizine (2.5mg/kg) potentiated the analgesic response to a low and intolerance dose of morphine (3mg/kg). Intra-MD microinjection of muscimol, a selective GABA-A receptor agonist (0.005-0.01μg/rat), increased the cetirizine/morphine-induced anti-allodynia, while muscimol by itself did not affect neuropathic pain. The neuropathic pain was associated with the increased PFC expression level of GFAP, suggesting the impact of chronic pain on PFC glial management. Interestingly, the anti-allodynia was associated with a decrease in the PFC expression level of GFAP under the drugs' co-administration. Thus, cetirizine has a significant potentiating effect on morphine response in neuropathic pain via interacting with the MD GABA-A receptors. It seems that neuropathic pain affects the prefrontal cortex GFAP signaling pathway. In clinical studies, these findings can be considered to create a combination therapy with low doses of GABA-A receptor agonist plus cetirizine and morphine to manage neuropathic pain.
Learn More >Arthritis is a kind of chronic disease that affects joints and muscles with the symptoms of joint pain, inflammation and limited movement of joints. Among various clinical therapies, drug therapy has been extensively applied because of its accessibility, safety and effectiveness. In recent years, the intra-articular injection has dramatic therapeutic effects in treating arthritis with high patient compliance and low side effects. In this review, we will introduce pathology of arthritis, along with the accessible treatment and diagnosis methods, then we will summarize major advances of current hopeful intra-articular delivery systems such as microspheres, hydrogels, nanoparticles and liposomes. At last, some safety assessments in the preclinical work and the main challenges for the further development of intra-articular treatment were also discussed.
Learn More >The mechanism of neuropathic pain after spinal cord injury is complex, and the communication between neurons, glia, and blood vessels in neurovascular units significantly affects the occurrence and development of neuropathic pain. After spinal cord injury, a domino chain reaction occurs in the neuron-glia-vessel, which affects the permeability of the blood-spinal cord barrier and jointly promotes the development of neuroinflammation. This article discusses the signal transduction between neuro-glial-endothelial networks from a multidimensional point of view and reviews its role in neuropathic pain after spinal cord injury.
Learn More >Endometriosis is the leading cause of chronic pelvic pain. Alterations in brain functional connectivity have been reported in adult women with endometriosis-associated pain (EAP), however, it is still unknown if similar patterns of changes exist in adolescents.
Learn More >Neuropathic pain is still a serious and unsolved health problem. Activation of α7 nicotinic acetylcholine receptor (α7nAChR) is known to modulate neuropathic pain by inhibiting microglial activation and BDNF/TrkB/KCC2 signaling. We previously identified that trifluoro-icaritin (ICTF) has an attenuated effect on spared nerve injury (SNI)-induced neuropathic pain, but its potential mechanisms remain unknown. Here, the pain-related behaviors were determined by paw withdrawal threshold (PWT), CatWalk gait analysis, rotarod test, open field test and elevated plus maze test. The expression of pain-related signal molecules was evaluated by Western blot and immunofluorescence staining. The results showed that ICTF (5.0 mg/kg, i.p.) successfully relieved SNI-induced mechanical allodynia and anxiety-like behavior, we subsequently found there existed either positive or negative correlation between mechanical allodynia and gait parameters or rotating speed following ICTF treatment. Moreover, ICTF not only enhanced the expression of spinal α7nAChR, KCC2, CD206 and IL-10, but also decreased the levels of spinal BDNF, TrkB, CD11b, Iba-1, CD40 and IL-1β in SNI rats. Conversely, α7nAChR antagonist α-Bgtx (I.T.) effectively reversed the inhibitory effects of ICTF on SNI rats, resulting in a remarkable improvement of mechanical allodynia, activation of microglia. and suppression of α7nAChR-mediated BDNF/TrkB/KCC2 signaling. Additionally, exogenous BDNF (I.T.) dramatically abrogated both blockade of BDNF/TrkB/KCC2 cascade and alleviation of mechanical allodynia by ICTF treatment. Altogether, the study highlighted that ICTF could relieve SNI-induced neuropathic pain by suppressing microglial activation via α7nAChR-mediated inhibition of BDNF/TrkB/KCC2 signaling in the spinal cord, suggesting that ICTF may be served as a possible painkiller against neuropathic pain.
Learn More >Percutaneous balloon compression (PBC) is a safe and effective method to treat trigeminal neuralgia. Despite it is known that intraoperative balloon volume is crucial in the prognosis of PBC patients and correlates with Meckel's cave (MC) size, it is a lack of objective and valid criteria for intraoperative balloon volume of PBC.
Learn More >Obstructive sleep apnea (OSA) is the most common form of sleep-disordered breathing. While patients on chronic opioids are at increased risk of sleep-disordered breathing, there is a lack of data on the relationship between opioid dose and OSA risk in particular. The STOP-Bang Questionnaire (SBQ) is a common screening tool for OSA, but it has not been well studied in patients on chronic opioid therapy.
Learn More >Morphine is one of the preferred drugs for the clinical treatment of pain. Both clinical and preclinical studies have reported sexual dimorphism in morphine analgesia. Different circulating levels of estrogen could be involved in sex differences in response to morphine analgesia. In our previous research, we found that capsaicin injection into the cervix of rats caused acute visceral pain that could be relieved by morphine. The role of estrogen in morphine analgesia in rats under uterine cervix pain and its underlying mechanisms remain to be explored.
Learn More >Extracorporeal shockwave therapy (ESWT) has shown its efficacy in treating chronic pain. Previous evidence has proven that ESWT in patients with chronic low-back pain (CLBP) results in significant reductions in pain. However, the optimal regimen for conducting ESWT in these patients remains unknown.
Learn More >Few investigations explore pain recovery comprehensively following urethral reconstruction, and understanding pain pathways that lead to discomfort following reconstruction has posed challenges. Options for pain control aside from opioids continue to be in the early forms of investigation, and remain an important strategy to combat the well-documented burden of the opioid epidemic. We conduct a detailed assessment of pain pathways in patients undergoing urethral reconstruction and further outline non-narcotic based pain management strategies in those undergoing urethroplasty.
Learn More >Childhood obesity can affect drug disposition and efficacy of ibuprofen. The primary objective was to assess efficacy of ibuprofen in obese children.
Learn More >This study aimed to determine the prevalence of chronic pain and its risk factors in patients with obstructive sleep apnea (OSA).
Learn More >Sleep disturbance, chronic pain and depressive symptoms later in life are modifiable risk factors and may contribute to frailty. However, much less is known about sex differences in the association between these concurrent symptoms and frailty in older patients. Therefore, we conducted this study to explore the associations of poor sleep quality, chronic pain, and depressive symptoms with frailty in older patients, and the sex-specific associations.
Learn More >Our understanding of how peripheral damage-sensing neurons (nociceptors) respond to noxious stimuli is fundamental to the development of effective analgesics. To date, numerous studies have presented diverging hypotheses on how nociceptors encode modality-specific stimuli, including labelled-line, intensity dependence or pattern theory. In this short review, we appraise data from electrophysiological, behavioural, imaging and molecular expression studies from the last 60 years, in order to obtain a coherent view of modality-specific sensing in peripheral sensory neurons. We propose a mechanistic explanation for the broad range of values obtained for the incidence of polymodal nociceptors that reconciles apparently contradictory data.
Learn More >Millions of people suffer from arthritis worldwide, consistently struggling with daily activities due to debilitating pain evoked by this disease. Perhaps the most intensively investigated type of inflammatory arthritis is rheumatoid arthritis (RA), where, despite considerable advances in research and clinical management, gaps regarding the neuroimmune interactions that guide inflammation and chronic pain in this disease remain to be clarified. The pain and inflammation associated with arthritis are not isolated to the joints, and inflammatory mechanisms induced by different immune and glial cells in other tissues may affect the development of chronic pain that results from the disease. This review aims to provide an overview of the state-of-the-art research on the roles that innate immune, and glial cells play in the onset and maintenance of arthritis-associated pain, reviewing nociceptive pathways from the joint through the dorsal root ganglion, spinal circuits, and different structures in the brain. We will focus on the cellular mechanisms related to neuroinflammation and pain, and treatments targeting these mechanisms from the periphery and the CNS. A comprehensive understanding of the role these cells play in peripheral inflammation and initiation of pain and the central pathways in the spinal cord and brain will facilitate identifying new targets and pathways to aide in developing therapeutic strategies to treat joint pain associated with RA.
Learn More >Cannabinoids are considered a therapeutic option to patients suffering from treatment refractory chronic pain (TRCP) insufficiently relieved by conventional analgesics or experiencing intolerable adverse events (AEs) from those. This study aimed to explore safety and effectiveness of oral cannabinoids among patients with TRCP.
Learn More >There is little information about the epidemiology and factors associated with opioid therapy in systemic lupus erythematosus (SLE). We aimed to assess the prevalence of opioid therapy and explore factors associated with long-term opioid therapy (LTOT) in patients with SLE.
Learn More >Lower urinary tract symptoms (LUTS) can occur in chronic pain populations at high rates and drastically affect quality of life. Hypnosis is a nonpharmacological treatment used in chronic pain known to have beneficial implications to health outside of pain reduction. This study evaluated the potential for hypnosis to reduce LUTS in a sample of individuals with chronic pain, if baseline LUTS severity affected outcomes, and specific LUTS that may respond to hypnosis.
Learn More >There are conflicting reports in the literature regarding the effectiveness of motor imagery (MI) and action observation (AO) in individuals with chronic non-specific neck pain (CNSNP). This study sought to systematically investigate whether mental practice has any impact on pain, functionality and quality-of-life in individuals with CNSNP.
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