Browse by Audience
Metabotropic γ-aminobutyric acid receptors (GABA) are involved in the modulation of synaptic responses in the central nervous system and have been implicated in neuropsychological conditions that range from addiction to psychosis. GABA belongs to class C of the G-protein-coupled receptors, and its functional entity comprises an obligate heterodimer that is composed of the GB1 and GB2 subunits. Each subunit possesses an extracellular Venus flytrap domain, which is connected to a canonical seven-transmembrane domain. Here we present four cryo-electron microscopy structures of the human full-length GB1-GB2 heterodimer: one structure of its inactive apo state, two intermediate agonist-bound forms and an active form in which the heterodimer is bound to an agonist and a positive allosteric modulator. The structures reveal substantial differences, which shed light on the complex motions that underlie the unique activation mechanism of GABA. Our results show that agonist binding leads to the closure of the Venus flytrap domain of GB1, triggering a series of transitions, first rearranging and bringing the two transmembrane domains into close contact along transmembrane helix 6 and ultimately inducing conformational rearrangements in the GB2 transmembrane domain via a lever-like mechanism to initiate downstream signalling. This active state is stabilized by a positive allosteric modulator binding at the transmembrane dimerization interface.
Learn More >Exposure treatments are shown to be effective in reducing pain-related fear and the perceived harmfulness of physical activities. However, due to the fragility of extinction its stability is questionable. We investigated the generalizability of exposure effects in chronic low back pain (CLBP) patients by integrating a behavioral test in the context of an intervention study.
Learn More >Neuronal-specific enolase (NSE) and protein S100B have gained considerable interest as the markers of CNS injury, glial cell activation, and/or blood-brain barrier (BBB) disruption. No studies have investigated NSE and S100B in cluster headache (CH), but these biomarkers could contribute to the understanding of CH.
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 >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 >To evaluate the cost-utility of 100 days of antibiotics in patients with chronic low back pain (LBP) and type I or II Modic changes included in the Antibiotic treatment In patients with chronic low back pain and Modic changes (AIM) study.
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 >Dorsal root ganglion (DRG) stimulation is a novel treatment of chronic neuropathic pain and has been shown to be efficacious across several case reports and randomized trials. However, long-term follow-up is limited, as are reports of complication rates. This study presents efficacy and complications for patients treated with DRG stimulation.
Learn More >We aimed to examine associations of cardiometabolic risk factors, and (pre)diabetes, with (sensorimotor) peripheral nerve function.
Learn More >