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Upregulation of cortical GABAA receptor concentration in fibromyalgia.

An imbalance between excitatory and inhibitory neurotransmission has been linked to fibromyalgia (FM). Magnetic resonance spectroscopy has shown increased levels of glutamate in the insula and posterior cingulate cortex in FM as well as reduced insular levels of gamma-aminobutyric acid (GABA). Both of these changes have been associated with increased pain sensitivity. However, it is not clear whether excitatory and/or inhibitory neurotransmission is altered across the brain. Therefore, the aim of this study was to quantify GABAA receptor concentration on the whole brain level in FM to investigate a potential dysregulation of the GABAergic system. Fifty-one postmenopausal women (26 FM, 25 matched controls) underwent assessments of pain sensitivity, attention and memory, psychological status and function, as well as positron emission tomography imaging using a tracer for GABAA receptors, [F]flumazenil. Patients showed increased pain sensitivity, impaired immediate memory, and increased cortical GABAA receptor concentration in the attention and default-mode networks. No decrease of GABAA receptor concentration was observed. Across the 2 groups, GABAA receptor concentration correlated positively with functional scores and current pain in areas overlapping with regions of increased GABAA receptor concentration. This study shows increased GABAA receptor concentration in FM, associated with pain symptoms and impaired function. The changes were widespread and not restricted to pain-processing regions. These findings suggest that the GABAergic system is altered, possibly indicating an imbalance between excitatory and inhibitory neurotransmission. Future studies should try to understand the nature of the dysregulation of the GABAergic system in FM and in other pain syndromes.

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Migraine-Specific Quality-of-Life Questionnaire (MSQ) Version 2.1 Score Improvement in Japanese Patients with Episodic Migraine by Galcanezumab Treatment: Japan Phase 2 Study.

Evaluate changes from baseline in health-related quality of life (QoL) in Japanese patients with episodic migraine receiving preventive treatment with galcanezumab (GMB).

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Efficacy and Safety of ASP0819 in Patients with Fibromyalgia: Results of a Proof-of-Concept, Randomized, Double-Blind, Placebo-Controlled Trial.

ASP0819 is a novel, non-opioid K3.1 channel opener that reverses abnormal nerve firing of primary sensory afferent nerves. Currently available treatments for fibromyalgia provide only modest relief and are accompanied by a host of adverse side effects.

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Low Incidence of Postoperative Respiratory Depression with Oliceridine Compared to Morphine: A Retrospective Chart Analysis.

Oliceridine, an investigational IV opioid, is a first-in-class G-protein selective agonist at the -opioid receptor. The G-protein selectivity results in potent analgesia with less recruitment of -arrestin, a signaling pathway associated with opioid-related adverse events (ORAEs). In randomized controlled studies in both hard and soft tissue models yielding surgical pain, oliceridine provided effective analgesia with a potential for an improved safety and tolerability profile at equianalgesic doses to morphine. The phase 3, open-label, single-arm, multicenter ATHENA trial demonstrated the safety, tolerability, and effectiveness of oliceridine in moderate to severe acute pain in a broad range of patients undergoing surgery or with painful medical conditions warranting use of an IV opioid. This retrospective, observational chart review study compared respiratory depression events associated with oliceridine administration as found in the ATHENA trial to a control cohort treated with conventional opioids.

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The Context Matters: A Retrospective Analysis of Life Stage at Chronic Pain Onset in Relation to Pain Characteristics and Psychosocial Outcomes.

Developmental life stage at chronic pain onset differs among chronic pain patients. Although pain affects multiple life domains, it is unknown whether the timing of chronic pain onset relates to pain characteristics and psychosocial outcomes. The purpose of this retrospective study was to investigate differences in pain characteristics and psychosocial outcomes in patients at different developmental life stages at chronic pain onset.

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Erenumab in Chronic Migraine Patients Who Previously Failed Five First-Line Oral Prophylactics and OnabotulinumtoxinA: A Dual-Center Retrospective Observational Study.

German authorities reimburse migraine prevention with erenumab only in patients who previously did not have therapeutic success with at least five oral prophylactics or have contraindications to such. In this real-world analysis, we assessed treatment response to erenumab in patients with chronic migraine (CM) who failed five oral prophylactics and, in addition, onabotulinumtoxinA (BoNTA). We analyzed retrospective data of 139 CM patients with at least one injection of erenumab from two German headache centers. Patients previously did not respond sufficiently or had contraindications to β-blockers, flunarizine, topiramate, amitriptyline, valproate, and BoNTA. Primary endpoint of this analysis was the mean change in monthly headache days from the 4-weeks baseline period over the course of a 12-weeks erenumab therapy. Secondary endpoints were changes in monthly migraine days, days with severe headache, days with acute headache medication, and triptan intake in the treatment period. Erenumab (starting dose 70 mg) led to a reduction of -3.7 (95% CI 2.4-5.1) monthly headache days after the first treatment and -4.7 (95% CI 2.9-6.5) after three treatment cycles ( < 0.001 for both). All secondary endpoint parameters were reduced over time. Half of patients (51.11%) had a >30% reduction of monthly headache days in weeks 9-12. Only 4.3% of the patients terminated erenumab treatment due to side effects. In this treatment-refractory CM population, erenumab showed efficacy in a real-world setting similar to data from clinical trials. Tolerability was good, and no safety issues emerged. Erenumabis is a treatment option for CM patients who failed all first-line preventives in addition to BoNTA.

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Capsaicin-Induced Skin Desensitization Differentially Affects A-Delta and C-Fiber-Mediated Heat Sensitivity.

Localized neuropathic pain can be relieved following the topical application of high-concentration capsaicin. This clinical effect is thought to be related to the temporary desensitization of capsaicin- and heat-sensitive epidermal nociceptors. The objective of the present study was to examine whether the changes in thermal sensitivity induced by high-concentration topical capsaicin can be explained entirely by desensitization of capsaicin-sensitive afferents. For this purpose, we characterized, in 20 healthy human volunteers, the time course and spatial extent of the changes in sensitivity to thermal stimuli preferentially activating heat-sensitive A-fiber nociceptors, heat-sensitive C-fiber afferents, and cool-sensitive A-fiber afferents. The volar forearm was treated with a high-concentration capsaicin patch for 1 h. Transient heat, warm and cold stimuli designed to activate Aδ- and C-fiber thermonociceptors, C-fiber warm receptors, and Aδ-fiber cold receptors were applied to the skin before and after treatment at days 1, 3, and 7. Reaction times, intensity ratings, and quality descriptors were collected. The stimuli were applied both within the capsaicin-treated skin and around the capsaicin-treated skin to map the changes in thermal sensitivity. We found that topical capsaicin selectively impairs heat sensitivity without any concomitant changes in cold sensitivity. Most interestingly, we observed a differential effect on the sensitivity to thermal inputs conveyed by Aδ- and C-fibers. Reduced sensitivity to Aδ-fiber-mediated heat was restricted to the capsaicin-treated skin, whereas reduced sensitivity to C-fiber-mediated heat extended well beyond the treated skin. Moreover, the time course of the reduced sensitivity to C-fiber-mediated input was more prolonged than the reduced sensitivity to Aδ-fiber-mediated input.

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Correlation between Galectin-3 and Early Herpes Zoster Neuralgia and Postherpetic Neuralgia: A Retrospective Clinical Observation.

This study aims to explore the value of serum galectin-3 in patients with herpes zoster neuralgia (HZN) and postherpetic neuralgia (PHN) and other factors influencing HZN and PHN occurrence. Samples from forty patients with herpes zoster neuralgia (HZN) (Group H), 40 patients with nonherpes zoster neuralgia (Group N), and 20 cases of health check-up were collected. Patients were divided into PHN group (Group A) and non-PHN group (Group B) according to the occurrence of PHN in Group H. Galectin-3, T-lymphocyte subsets, and IL-6 were recorded in all patients. The changes of galectin-3 in patients with early HZN and PHN were analyzed by single-factor analysis and multifactor analysis. The age (=0.012) and NRS scores ( < 0.001) of PHN patients were significantly higher than those of non-PHN patients and other neuralgia patients. The ratio of CD3+ ( = 80.336, < 0.001), CD4+ ( = 12.459, < 0.001) lymphocyte subsets, and CD4+/CD8+ ( = 15.311, < 0.001) decreased significantly in PHN patients. The level of blood IL-6 ( = 139.446, < 0.001) in PHN patients was significantly increased. Serum galectin-3 was significantly higher in HZN patients than in PHN patients ( < 0.05); IL-6 (OR = 10.002, 95% CI: 3.313-30.196, < 0.001) and galectin-3 (OR = 3.719, 95% CI: 1.261-10.966, =0.017) were the risk factors for HZN; galectin-3 (OR = 17.646, 95% CI: 2.795-111.428, =0.002) was also the risk factor for PHN. ROC curve analysis also showed that serum galectin-3 was a better predictor of poor prognosis (AUC = 0.934, < 0.001). Therefore, as an independent risk factor of HZN and PHN, serum galectin-3 may be used as a new biochemical marker in clinical practice.

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Use of IMMPACT domains in clinical trials of acupuncture for chronic pain: A methodological survey.

Acupuncture is one of the therapeutic resources used for the management of chronic pain. Variability in outcome measurements in randomized clinical trials of non-oncologic chronic pain (RCT-NOCP) generates inconsistencies in determining effects of treatments. The objective of this survey was to assess the adherence to the recommendations made by the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) in the measurement of RCT-NOCP of acupuncture. This methodological research made a systematic search for eligible studies from different sources of information. Eligible studies included those with number of patients ≥100, who randomized and allocated patients with chronic non-oncologic pain to be treated with acupuncture or with "sham" acupuncture, or non-acupuncture. This research included the recommendations for IMMPACT in the measurement of RCT-NOCP: presence of outcomes pain, physical function, emotional state and improvement perception of patient, the source of the outcome information pain and the tools used to measure such domains. From a total of 1,386 studies, 24 were included in this survey. Eleven studies presented low risk of bias. Pain outcome was measured in 23 studies, physical function in 22 studies, emotional state in 14 studies and improvement perception of patient in one study. As for the pain outcome, the patient was the information source in 50% of the studies. The measurement tools recommended for IMMPACT were included in eight studies (35%) that evaluated pain, one study that evaluated the emotional state (7%), and one study that evaluated the improvement perception and satisfaction of patient. It was observed that studies which did not adhere to the recommendations had more favorable results for acupuncture in the outcome pain. This study concludes that randomized clinical trials that used acupuncture to manage chronic pain failed to adhere to IMMPACT recommendations. Clinical societies and IMMPACT do not share the same recommendations. This fact reflects in the diversity of outcomes and instruments adopted in the studies, making it difficult to compare the results.

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Research on the Relationship Between Vestibular Migraine With/Without Cognitive Impairment and Brainstem Auditory Evoked Potential.

Vestibular migraine (VM) is the most common cause of spontaneous vertigo with no specific physical and laboratory examinations, and is an under-recognized entity with substantial burden for the individual and the society. In this study, by observing the brainstem auditory evoked potential (BAEP) and cognitive function of VM patients, the possible laboratory diagnostic indicators of VM and the influence of disease on cognitive function were discussed. The study included 78 VM patients, 76 migraine patients, and 79 healthy individuals. The age, gender, and other clinical history of the three groups matched. All participants underwent BAEP examinations, in which patients in the migraine group and outpatients of the VM group were in the interictal period, and inpatients in the VM group were examined during episodes, while all patients tested for the Addenbrooke's cognitive examination-revised (ACE-R) scale were in the interictal period. The differences in BAEP and ACE-R scores between the three groups of members and their relationship with the clinical features of VM patients were analyzed. The peak latency of I, III, and V wave in the BAEP of the VM group was longer than that of the migraine group and the control group ( < 0.05). The peak latency of V wave in the BAEP of the migraine group was longer than that of the control group ( < 0.05). The ACE-R of the VM group scored lower than the migraine group in terms of language fluency and language ( < 0.05), and lower than the control group in terms of total score, language fluency, language, and visuospatial ( < 0.05); and the ACE-R of the migraine group scored lower than the control group in the total score and visuospatial ( < 0.05). Migraine patients have brainstem dysfunction, and VM patients have more severe brainstem dysfunction than migraine patients, suggesting that VM patients have both central nervous system damage and peripheral nerve damage. Migraine patients have cognitive impairment, while cognitive impairment in VM patients is more severe than in migraine patients.

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