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We aimed to examine associations of cardiometabolic risk factors, and (pre)diabetes, with (sensorimotor) peripheral nerve function.
Learn More >Sleep disturbance is associated with persistence and exacerbation of chronic pain. As this relationship seems to be bidirectional, factors underpinning sleep disturbance may prove valuable in multimodal rehabilitation approaches. The aim of this cross-sectional study was to examine the impact of psychological symptoms on subjective and objective sleep measures in patients with chronic musculoskeletal pain (CMP) as compared to healthy controls (HC).
Learn More >Randomized studies have reported a positive effect of candesartan, an angiotensin II receptor antagonist, in migraine prevention. The aim of our study was to explore patient subjective efficacy of candesartan in a real-world sample of migraine patients and try to identify predictors of candesartan response. We audited the clinical records of 253 patients who attended the King's College Hospital, London, from February 2015 to December 2017, looking specifically at their response to candesartan. Univariate and multivariate logistic regression models were used to identify predictors of headache benefit. Odds ratios (OR) with confidence intervals (CI) 95% were calculated. Eighty-one patients (chronic migraine, n = 68) were included in the final analysis. Thirty-eight patients reported a positive response to candesartan, while 43 patients did not have a meaningful therapeutic effect. The median dose of candesartan was 8 mg and the median treatment period was 6 months. In a univariate logistic regression model, the presence of daily headache was associated with reduced odds of headache benefit (OR 0.39, 95% CI 0.16-0.96, p = 0.04). In multivariate logistic regression model, younger age (OR 0.92, 95% CI 0.87-0.98, p = 0.006) and longer disease duration (OR 1.06, 95% CI 1.01-1.12, p = 0.03) were associated with a good response to candesartan, while the presence of daily headache was associated with reduced odds of headache benefit (OR 0.16, 95% CI 0.04-0.71, p = 0.01). Having failed up to nine preventives in patients did not predict a treatment failure with candesartan as well. Candesartan yields clinical benefits in difficult-to-treat migraine patients, irrespective of previous failed preventives.
Learn More >Pain medication plays an important role in the treatment of acute and chronic pain conditions, but some drugs, opioids in particular, have been overprescribed or prescribed without adequate safeguards, leading to an alarming rise in medication-related overdose deaths. The NIH Helping to End Addiction Long-term (HEAL) Initiative is a trans-agency effort to provide scientific solutions to stem the opioid crisis. One component of the initiative is to support biomarker discovery and rigorous validation in collaboration with industry leaders to accelerate high-quality clinical research into neurotherapeutics and pain. The use of objective biomarkers and clinical trial end points throughout the drug discovery and development process is crucial to help define pathophysiological subsets of pain, evaluate target engagement of new drugs and predict the analgesic efficacy of new drugs. In 2018, the NIH-led Discovery and Validation of Biomarkers to Develop Non-Addictive Therapeutics for Pain workshop convened scientific leaders from academia, industry, government and patient advocacy groups to discuss progress, challenges, gaps and ideas to facilitate the development of biomarkers and end points for pain. The outcomes of this workshop are outlined in this Consensus Statement.
Learn More >G-protein-coupled receptors (GPCRs) are key signaling proteins that mostly function as monomers, but for several receptors constitutive dimer formation has been described and in some cases is essential for function. Using single-molecule microscopy combined with super-resolution techniques on intact cells, we describe here a dynamic monomer-dimer equilibrium of µ-opioid receptors (µORs), where dimer formation is driven by specific agonists. The agonist DAMGO, but not morphine, induces dimer formation in a process that correlates both temporally and in its agonist- and phosphorylation-dependence with β-arrestin2 binding to the receptors. This dimerization is independent from, but may precede, µOR internalization. These data suggest a new level of GPCR regulation that links dimer formation to specific agonists and their downstream signals.
Learn More >Besides neuraxial analgesia, non-pharmacological methods are also proposed to help women coping with pain during labor. We aimed to identify the individual and organizational factors associated with the use of non-pharmacological analgesia for labor pain management. Women who attempted vaginal delivery with labor analgesia were selected among participants included in the 2016 National Perinatal Survey, a population-based cross-sectional study. Labor analgesia was studied as neuraxial analgesia alone, non-pharmacological analgesia alone, and neuraxial and non-pharmacological analgesia combined. The associations were studied by multilevel multinomial logistic regression. Among the 9,231 women included, 62.4% had neuraxial analgesia alone, 6.4% had non-pharmacological analgesia alone and 31.2% had both. Non-pharmacological analgesia alone or combined with neuraxial analgesia were both associated with high educational level (adjusted odds ratio 1.55; 95%CI, 1.08 to 2.23 and 1.39; 95%CI, 1.18 to 1.63), antenatal preference to deliver without neuraxial analgesia, and public maternity unit status. Non-pharmacological analgesia alone was more frequent among multiparous women, and in maternity units with an anesthesiologist not dedicated to delivery unit (1.57; 95%CI, 1.16 to 2.12) and with the lowest midwife workload (2.15; 95%CI, 1.43 to 3.22). Neuraxial and non-pharmacological analgesia combined was negatively associated with inadequate prenatal care (0.70; 95%CI, 0.53 to 0.94). In France, most women who had non-pharmacological analgesia during labor used it as a complementary method to neuraxial analgesia. The use of non-pharmacological analgesia combined with neuraxial analgesia mainly depends on the woman's preference, but also on socioeconomic factors, quality of prenatal care and care organization.
Learn More >Musculoskeletal disorders such as knee osteoarthritis (OA) are the primary cause of chronic pain in older adults. Recommended self-management strategies for knee OA include staying physically active in the face of pain, but many patients avoid activities they are capable of doing. The overall purpose of this study was to examine the extent to which daily pain catastrophizing, a maladaptive coping strategy, could influence OA patients' physical activity and sedentary behavior. The current study utilized data from 143 older knee OA patients who completed electronic daily diaries for 22 days and wore an accelerometer to capture physical activity and sedentary behavior. At the beginning of each day, patients reported their pain catastrophizing regarding the day ahead. Results from multilevel models demonstrated that on mornings when patients catastrophized more than usual about their pain in the day ahead, they spent more time in sedentary behavior and engaged in fewer minutes of moderate to vigorous physical activity that day. Cross-day lagged analyses further showed that the effect of morning pain catastrophizing on subsequent sedentary behavior extended to the next day. More time spent in sedentary behavior, in turn, contributed to greater pain catastrophizing the next morning. These findings support the mechanistic role of daily pain catastrophizing in the avoidance of physical activity for older OA patients, and suggest that effective interventions for pain catastrophizing may also reduce sedentary behavior and enhance physical activity, with longer-term benefits for pain management, physical function, and overall health.
Learn More >Children diagnosed with Christianson Syndrome (CS), a rare X-linked neurodevelopmental disorder characterized by intellectual disability, epilepsy, ataxia and mutism, also suffer from hyposensitivity to pain. This places them at risk of sustaining serious injuries that often go unattended. CS is caused by mutations in the alkali cation/proton exchanger SLC9A6/NHE6 that regulates recycling endosomal pH homeostasis and trafficking. Yet it remains unclear how defects in this transporter lead to altered somatosensory functions. In this study, we validated a Nhe6 knockout (KO) mouse as a model of CS and used it to identify the cellular mechanisms underlying the elevated pain tolerance observed in CS patients. Within the central nervous system, NHE6 immunolabelling is detected in a small percentage of cortical neurons involved in pain processing, including those within the primary somatosensory and the anterior cingulate cortices as well as the periaqueductal grey. Interestingly, it is expressed in a larger percentage of nociceptors. Behaviourally, Nhe6 KO mice have decreased nocifensive responses to acute noxious thermal, mechanical and chemical (i.e., capsaicin) stimuli. The reduced capsaicin-sensitivity in the KO mice correlates with a decreased expression of the transient receptor potential channel TRPV1 at the plasma membrane and capsaicin-induced Ca influx in primary cultures of nociceptors. These data indicate that NHE6 is a significant determinant of nociceptor function and pain behaviours, vital sensory processes that are impaired in CS.
Learn More >Musculoskeletal pain is the greatest cause of disability worldwide. Due to its increasing prevalence and burden, the importance of affordable treatments has been highlighted. Text messages interventions are accessible, low-cost and effective in promoting healthy behaviour and managing chronic diseases. However, little is known about their role in musculoskeletal pain. This systematic review was conducted to appraise the literature on the effects of text messages (as an intervention or a component of an intervention) compared to any control on pain and function in people with musculoskeletal pain (PROSPERO: CRD42018117371). MEDLINE, EMBASE, CINAHL, Cochrane and PEDro databases were searched from inception to April 2020. Keywords relating to musculoskeletal pain, text messages and randomised controlled trials were combined. Methodological quality was assessed using the PEDro score. Of the 12,022 studies identified, 11 were included, with a mean PEDro score of 5.4/10 points (SD 1.3). Pooled analyses were not performed due to heterogeneity of interventions and clinical characteristics. When text messages were added to and compared with usual care, some positive effects were found only on treatment adherence. Although small and inconsistent, some positive effects were reported for pain intensity, function, care seeking behaviour, adherence and quality of life when text messages were added to multicomponent interventions. Moreover, text message and telephone counselling interventions had similar effects on function. Overall included studies were of limited methodological quality and heterogeneous. However, our results indicate potential benefits of text messages in the treatment of musculoskeletal pain which need to be confirmed in future trials.
Learn More >Although pain is defined as a sensory and emotional experience, it is traditionally researched and clinically treated separately from emotion. Conceptual and mechanistic relationships between these constructs highlight the need for better understanding of their bi-directional influences and the value of bridging the pain and emotion research and clinical communities.
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