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Central disinhibition (CD), as applied to pain, decreases thresholds of endogenous systems. This provokes onset of spontaneous or evoked pain in an individual beyond the ability of the nervous system to inhibit pain resulting from a disease or tissue damage. The original CD concept as proposed by Craig entails a shift from the lateral pain pathway (i.e. discriminative pain processing) towards the medial pain pathway (i.e. emotional pain processing), within an otherwise neurophysiological intact environment. In this review, the original CD concept as proposed by Craig is extended by the primary "nociceptive pathway damage – CD" concept and the secondary "central pathway set point – CD". Thereby, the original concept may be transferred into anatomical and psychological non-functional conditions. We provide examples for either primary or secondary CD concepts within different clinical etiologies as well as present surrogate models, which directly mimic the underlying pathophysiology (A-fiber block) or modulate the CD pathway excitability (thermal grill). The thermal grill has especially shown promising advancements, which may be useful to examine CD pathway activation in the future. Therefore, within this topical review, a systematic review on the thermal grill illusion is intended to stimulate future research. Finally, the authors review different mechanism-based treatment approaches to combat CD pain.
Learn More >Osteoarthritis results in chronic pain and loss of function. Proinflammatory cytokines create both osteoarthritis pathology and pain. Current treatments are poorly effective, have significant side effects, and have not targeted the cytokines central to osteoarthritis development and maintenance. Interleukin-10 is an anti-inflammatory cytokine that potently and broadly suppresses proinflammatory cytokine activity. However, interleukin-10 protein has a short half-life in vivo and poor joint permeability. For sustained IL-10 activity, we developed a plasmid DNA-based therapy that expresses a long-acting human interleukin-10 variant (hIL-10var). Here, we describe the 6-month GLP toxicology study of this therapy. Intra-articular injections of hIL-10var pDNA into canine stifle joints up to 1.5 mg bilaterally were well-tolerated and without pathologic findings. This represents the first long-term toxicologic assessment of intra-articular pDNA therapy. We also report results of a small double-blind, placebo-controlled study of the effect of intra-articular hIL-10var pDNA on pain measures in companion (pet) dogs with naturally occurring osteoarthritis. This human IL-10-based targeted therapy reduced pain measures in the dogs, based on veterinary and owner ratings, without any adverse findings. These results with hIL-10var pDNA therapy, well-tolerated and without toxicologic effects, establish the basis for clinical trials of a new class of safe and effective therapies for OA.
Learn More >We intended to clarify the effect of gender and A118G polymorphism of Opioid Receptor μ1 (OPRM1) on the required morphine for patients to maintain Visual Analogue Scale ≦ 3 for post-operative pain control after total knee replacement (TKR).
Learn More >Malfunctions of voltage-gated sodium and calcium channels (encoded by and family genes, respectively) have been associated with severe neurologic, psychiatric, cardiac, and other diseases. Altered channel activity is frequently grouped into gain or loss of ion channel function (GOF or LOF, respectively) that often corresponds not only to clinical disease manifestations but also to differences in drug response. Experimental studies of channel function are therefore important, but laborious and usually focus only on a few variants at a time. On the basis of known gene-disease mechanisms of 19 different diseases, we inferred LOF ( = 518) and GOF ( = 309) likely pathogenic variants from the disease phenotypes of variant carriers. By training a machine learning model on sequence- and structure-based features, we predicted LOF or GOF effects [area under the receiver operating characteristics curve (ROC) = 0.85] of likely pathogenic missense variants. Our LOF versus GOF prediction corresponded to molecular LOF versus GOF effects for 87 functionally tested variants in and (ROC = 0.73) and was validated in exome-wide data from 21,703 cases and 128,957 controls. We showed respective regional clustering of inferred LOF and GOF nucleotide variants across the alignment of the entire gene family, suggesting shared pathomechanisms in the family genes.
Learn More >Chronic non-cancer pain, a disabling and distressing condition, is common in adults. It is a global public health problem and economic burden on health and social care systems and on people with chronic pain. Psychological treatments aim to reduce pain, disability and distress. This review updates and extends its previous version, published in 2012.
Learn More >Sensory information processing in robot skins currently rely on a centralized approach where signal transduction (on the body) is separated from centralized computation and decision-making, requiring the transfer of large amounts of data from periphery to central processors, at the cost of wiring, latency, fault tolerance and robustness. We envision a decentralized approach where intelligence is embedded in the sensing nodes, using a unique neuromorphic methodology to extract relevant information in robotic skins. Here we specifically address pain perception and the association of nociception with tactile perception to trigger the escape reflex in a sensorized robotic arm. The proposed system comprises self-healable materials and memtransistors as enabling technologies for the implementation of neuromorphic nociceptors, spiking local associative learning and communication. Configuring memtransistors as gated-threshold and -memristive switches, the demonstrated system features in-memory edge computing with minimal hardware circuitry and wiring, and enhanced fault tolerance and robustness.
Learn More >A core outcome set (COS) represents the agreed minimum set of domains and measurement instruments that should be measured and reported in any clinical trial for a given condition. In BMS randomized controlled trials (RCTs), the outcomes identified in the existing literature regarding the efficacy of therapeutic interventions are numerous and diverse. Although the standardized IMMPACT core outcome domains has been developed for measurement of outcomes in chronic pain RCTs, no BMS-specific COS have been adopted and validated. With the evolving landscape of BMS management end points and the development of new therapies, a consensus on a COS for use in future BMS trials is paramount to reduce heterogeneity in outcome reporting. The aim of this study was to reach a consensus for adopting the standardized Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) outcome domains, and their tools of assessment, for burning mouth syndrome (BMS) clinical trials and clinical practice.
Learn More >Determine whether common migraine comorbidities affect the efficacy and safety of lasmiditan, a 5-HT receptor agonist approved in the United States for the acute treatment of migraine. In SPARTAN and SAMURAI (double-blind Phase 3 clinical trials), patients with migraine were randomized to oral lasmiditan 50 mg (SPARTAN only), 100 mg, 200 mg, or placebo. Lasmiditan increased the proportion of pain-free and most bothersome symptom (MBS)-free patients at 2 hours after dose compared with placebo. Most common treatment-emergent adverse events (TEAEs) were dizziness, paraesthesia, somnolence, fatigue, nausea, muscular weakness, and hypoesthesia. Based upon literature review of common migraine comorbidities, Anxiety, Allergy, Bronchial, Cardiac, Depression, Fatigue, Gastrointestinal, Hormonal, Musculoskeletal/Pain, Neurological, Obesity, Sleep, and Vascular Comorbidity Groups were created. Using pooled results, efficacy and TEAEs were assessed to compare patients with or without a given common migraine comorbidity. To compare treatment groups, p-values were calculated for treatment-by-subgroup interaction, based on logistic regression with treatment-by-comorbidity condition status (Yes/No) as the interaction term; study, treatment group, and comorbidity condition status (Yes/No) were covariates. Differential treatment effect based upon comorbidity status was also examined. Trial registration at clinicaltrials.gov: SAMURAI (NCT02439320) and SPARTAN (NCT02605174). Across all the Comorbidity Groups, with the potential exception of fatigue, treatment-by-subgroup interaction analyses did not provide evidence of a lasmiditan-driven lasmiditan versus placebo differential treatment effect dependent on Yes versus No comorbidity subgroup for either efficacy or TEAE assessments. The efficacy and safety of lasmiditan for treatment of individual migraine attacks appear to be independent of comorbid conditions.
Learn More >Self-compassion meditation, which involves compassion toward the self in moments of suffering, shows promise for improving pain-related functioning, but its underlying mechanisms are unknown. This longitudinal, exploratory pilot study investigated the effects of a brief (eight contact hours, two weeks of home practice) self-compassion training on pain-related brain processing in chronic low back pain (cLBP).
Learn More >Chemotherapy-induced peripheral neuropathy (CIPN) is among the most disabling and frustrating problems for cancer survivors. The neurotoxicity caused by cisplatin varies greatly among patients, and few predictors of appearance, duration of symptoms, susceptibility, or severity are available. A deeper understanding of the mechanisms underlying individual differences in status, severity, or sensitivity in response to cisplatin treatment is therefore required. By analyzing the GSE64174 gene expression profile and constructing a weighted gene co-expression network analysis (WGCNA) network, we screened gene modules and hub genes related to CIPN status, severity and sensitivity. We first identified the transcriptome profile of mouse dorsal root ganglion (DRG) samples and transformed their genes to human DRG counterparts. We then constructed WGCNA gene modules via optimal soft-threshold power-identification and module-preservation analysis. Comprehensive analysis and identification of module hub genes were performed via functional-enrichment analysis and significant common hub genes were identified, including "Cytoscape_cytoHubba," "Cytoscape_MCODE," and "Metascape_MCODE." Brown, green, and blue modules were selected to represent CIPN sensitivity, status and severity, resepectively, via trait-module correlational analysis. Additionally, functional enrichment analysis results indicated that these three modules were associated with some crucial biological functions, such as neutrophil migration, chemokine-mediated signaling pathway, and PI3K-Akt signaling pathway. We then identified seven common hub genes via three methods, including CXCL10, CCL21, CCR2, CXCR4, TLR4, NPY1R, and GALR2, related to CIPN status, severity and sensitivity. Our results provide possible targets and mechanism insights into the development and progress of CIPN, which can guide further transformation and pre-clinical research.
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