Reply to Moman and Hooten
No abstract available (Source: Pain)
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Correspondence Source Type: research

Noninvasive motor cortex stimulation and quantitative sensory testing: more certainty is needed
No abstract available (Source: Pain)
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Correspondence Source Type: research

Effect of a brief scenario-tailored educational program on parents' risk knowledge, perceptions, and decisions to administer prescribed opioids: a randomized controlled trial
This randomized, controlled trial evaluated whether a brief educational program (ie, Scenario-Tailored Opioid Messaging Program [STOMP]) would improve parental opioid risk knowledge, perceptions, and analgesic efficacy; ensure safe opioid use decisions; and impact prescription opioid use after surgery. Parent–child dyads (n = 604) who were prescribed an opioid for short-term use were randomized to routine instruction (Control) or routine plus STOMP administered preoperatively. Baseline and follow-up surveys assessed parents' awareness and perceived seriousness of adverse opioid effects, and their analgesic efficacy. ...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

The sociocultural context of pediatric pain: an examination of the portrayal of pain in children's popular media
This study examined how pain is portrayed and gendered in children's popular media. A cross-section of children's media targeted towards 4- to 6-year-old children was selected based on popularity, including 10 movies and the first season of 6 television shows. Pain instances were extracted and coded using 2 established observational coding systems assessing sufferer pain characteristics and observer responses (eg, empathic responses). Findings identified 454 instances of pain across the selected media. Violent pain (ie, intentionally inflicted) and injuries were most commonly represented, whereas everyday, chronic-type, an...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

The partial saphenous nerve injury model of pain impairs reward-related learning but not reward sensitivity or motivation
This study investigated different aspects of reward-related behaviour in a rodent model of chronic pain, the partial saphenous nerve injury (PSNI). Using our reward-learning assay, an impairment in reward learning was observed with no difference in sucrose preference, consistent with a lack of effect on reward sensitivity and similar to the effects seen in depression models. In a successive negative contrast task, chronic pain was not associated with changes in motivation for reward either under normal conditions or when reward was devalued although both sham and PSNI groups exhibited the expected negative contrast effect....
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Ambulatory continuous peripheral nerve blocks to treat postamputation phantom limb pain: a multicenter, randomized, quadruple-masked, placebo-controlled clinical trial
Phantom limb pain is thought to be sustained by reentrant neural pathways, which provoke dysfunctional reorganization in the somatosensory cortex. We hypothesized that disrupting reentrant pathways with a 6-day-long continuous peripheral nerve block reduces phantom pain 4 weeks after treatment. We enrolled patients who had an upper- or lower-limb amputation and established phantom pain. Each was randomized to receive a 6-day perineural infusion of either ropivacaine or normal saline. The primary outcome was the average phantom pain severity as measured with a Numeric Rating Scale (0-10) at 4 weeks, after which an optional ...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Bidirectional longitudinal associations between loneliness and pain, and the role of inflammation
Pain and loneliness are consistently associated, but the direction of the relationship is uncertain. We assessed bidirectional associations over a 4-year period in a sample of 4906 men and women (mean 65.1 ± 8.72 years) who were participants in the English Longitudinal Study of Ageing. The role of inflammation in these links was also investigated. Pain was defined by reports of being often troubled by pain at a moderate or severe intensity, whereas loneliness was measured using the shortened UCLA scale. Age, sex, ethnicity, educational attainment, wealth as a marker of socioeconomic resources, marital status, physic...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Balloon compression vs radiofrequency for primary trigeminal neuralgia: a randomized, controlled trial
Surgical procedures are necessary in up to 50% of trigeminal neuralgia patients. Although radiofrequency (RF) is more widely used, it is associated with high intraprocedural costs and long technical learning time. Other simpler procedures such as balloon compression (BC) require a lower training period and have significant lower costs. We evaluated the effects of BC and RF in pain control in primary trigeminal neuralgia in a randomized, double-blinded, head-to-head trial. Individuals were randomly allocated in 1 of 2 groups: BC and RF. Throughout pain, psychological and quality of life measurements were performed at baseli...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Sexual dimorphism in the contribution of neuroendocrine stress axes to oxaliplatin-induced painful peripheral neuropathy
Although clinical studies support the suggestion that stress is a risk factor for painful chemotherapy-induced peripheral neuropathy (CIPN), there is little scientific validation to support this link. Here, we evaluated the impact of stress on CIPN induced by oxaliplatin, and its underlying mechanisms, in male and female rats. A single dose of oxaliplatin produced mechanical hyperalgesia of similar magnitude in both sexes, still present at similar magnitude in both sexes, on day 28. Adrenalectomy mitigated oxaliplatin-induced hyperalgesia, in both sexes. To confirm the role of neuroendocrine stress axes in CIPN, intratheca...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Adaptive alterations in the mesoaccumbal network after peripheral nerve injury
The nucleus accumbens (NAc) and the ventral tegmental area (VTA) are critical hubs in the brain circuitry controlling chronic pain. Yet, how these 2 regions interact to shape the chronic pain state is poorly understood. Our studies show that in mice, spared nerve injury (SNI) induced alterations in the functional connectome of D2-receptor expressing spiny projection neurons in the core region of the NAc—enhancing connections with prelimbic cortex and weakening them with basolateral amygdala. These changes, which were attributable in part to SNI-induced suppression of VTA dopaminergic signaling, were adaptive because ...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Examination of the clinical factors associated with attendance at emergency departments for chronic pain management and the cost of treatment relative to that of other significant medical conditions
We examined ED utilisation in patients with CP, identified risk factors associated with attendance for chronic musculoskeletal pain (CMP), and estimated the comparative cost of treatment. The study cohort comprised a random sample of 3700 adults from the general population in Tayside, Scotland. Linked regional extracts, spanning a 12-month period, were obtained from national registers, providing information on ED attendances, community-dispensed prescribing, and outpatient clinic attendances. The National Health Service Scotland Cost Book was used to ascertain the current average cost of an ED attendance (£130; ∼...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Avoidance behaviour performed in the context of a novel, ambiguous movement increases threat and pain-related fear
The fear-avoidance model of chronic pain predicts that catastrophic (mis)interpretation of pain elicits pain-related fear that in turn may spur avoidance behaviour leading to chronic pain disability. Here, we investigated whether performing a movement to avoid a painful stimulus in the context of a novel movement increases threat and pain-related fear towards this novel movement and whether avoidance behaviour persisted when given the choice between performing the acquired movement to avoid a painful stimulus or an alternative, novel movement. Applying a robotic arm-reaching task, participants could choose between 2 moveme...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Neuropathic pain: clinical classification and assessment in patients with pain due to cancer
Neuropathic cancer pain (NcP) is associated with worse treatment responses and specific therapy indications, but a standardized clinical diagnosis of NcP is still lacking. This is a prospective observational study on outpatients with cancer, comparing different clinical approaches with NcP evaluation. A three-step assessment of NcP was performed using DN4 (cutoff of 4), palliative care physician Clinical Impression, including etiology and pain syndrome identification, and Retrospective Clinical Classification by a board of specialists with the IASP Neuropathic Pain Special Interest Group criteria. Neuropathic cancer pain c...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Systematic evaluation of commercially available pain management apps examining behavior change techniques
This study systematically evaluated commercially available pain management apps for evidence-based BCTs and app quality. Pain management apps were identified using the search terms “pain” and “pain management” in the App and Google Play stores. Reviewed apps were specific to pain management, in English, for patients, and free. A total of 28 apps were coded using the taxonomy of BCTs. App quality was assessed using the Mobile App Rating Scale. Apps included 2 to 15 BCTs (M = 7.36) and 1 to 8 (M = 4.21) pain management–specific BCTs. Prompt intention formation, instruction, behavioral-health lin...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Pain sensitivity and the primary sensorimotor cortices: a multimodal neuroimaging study
The primary somatosensory cortex (SI) is a critical part of the neural substrate underlying interindividual differences in pain sensitivity. Here, we investigated whether resting-state functional connectivity, gray matter density (GMD), and GABA and Glx (glutamate and glutamine) levels of the sensorimotor cortices were related to pain thresholds and whether such imaging measures could predict high and low pain sensitivity. Functional, structural, and spectroscopic magnetic resonance data were obtained from 48 healthy participants together with pain thresholds of the right index finger. Left and right sensorimotor networks ...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Identifying biopsychosocial factors that impact decompressive laminectomy outcomes in veterans with lumbar spinal stenosis: a prospective cohort study
One in 3 patients with lumbar spinal stenosis undergoing decompressive laminectomy (DL) to alleviate neurogenic claudication do not experience substantial improvement. This prospective cohort study conducted in 193 Veterans aimed to identify key spinal and extraspinal factors that may contribute to a favorable DL outcome. Biopsychosocial factors evaluated pre-DL and 1 year post-DL were hip osteoarthritis, imaging-rated severity of spinal stenosis, scoliosis/kyphosis, leg length discrepancy, comorbidity, fibromyalgia, depression, anxiety, pain coping, social support, pain self-efficacy, sleep, opioid and nonopioid pain medi...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Longitudinal and concurrent relationships between caregiver–child behaviours in the vaccination context and preschool attachment
This article consists of 2 separate studies in which the overarching aim was to examine the relationships between caregiver–child behaviours in the vaccination context (infant and preschool) and preschool attachment outcomes. It provides for the first time an examination of acute pain behaviours during early childhood and how it relates to a critical aspect of child development (ie, attachment status) at the end of early childhood. Study 1 examined the longitudinal relationships between caregiver–infant behaviours during infants' first routine vaccination (2 months) and preschool attachment (n = 84). Study 2 ex...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Visuomotor impairments in complex regional pain syndrome during pointing tasks
Complex regional pain syndrome (CRPS) is thought to be characterized by cognitive deficits affecting patients' ability to represent, perceive, and use their affected limb as well as its surrounding space. This has been tested, among others, by straight-ahead tasks testing oneself's egocentric representation, but such experiments lead to inconsistent results. Because spatial cognitive abilities encompass various processes, we completed such evaluations by varying the sensory inputs used to perform the task. Complex regional pain syndrome and matched control participants were asked to assess their own body midline either vis...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Impaired short-term visual paired associative plasticity in patients with migraine between attacks
A common experimental neurophysiological method to study synaptic plasticity is pairing activity of somatosensory afferents and motor cortical circuits, so-called paired associative stimulation (PAS). Dysfunctional inhibitory and excitatory PAS mechanisms within the sensorimotor system were described in patients with migraine without aura (MO) between attacks. We have recently observed that the same bidirectional PAS rules also apply to the visual system. Here, we have tested whether dysfunctioning associative plasticity might characterize the visual system of patients with MO. In 14 patients with MO between attacks and in...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Not as “blurred” as expected? Acuity and spatial summation in the pain system
Spatial acuity measured by 2-point discrimination (2PD) threshold and spatial summation of pain (SSp) are useful paradigms to probe the pain system in humans. Whether the results of these paradigms are influenced by different stimulus modalities and intensities is unclear. The aim of this study was to test 2PD controlling the stimulus modality and the intensity and to investigate the effect of modality on SSp. Thirty-seven healthy volunteers were tested for 2PDs with 2 stimulus modalities (electrocutaneous and mechanical) and intensity (noxious and innocuous). For each condition, participants received stimuli to either 1 o...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Patients' perceptions of the pathways linking chronic pain with problematic substance use
Approximately one-half of patients with substance use disorders (SUDs) experience chronic pain. Yet, how patients perceive the relationship between their substance use and chronic pain remains poorly understood. We sought to identify how patients with comorbid SUD and chronic pain describe the relationship between, and mechanisms linking, these conditions. We conducted qualitative interviews with 34 patients engaged in SUD treatment who were also diagnosed with chronic pain. Interviews were transcribed verbatim and coded by both primary and secondary coders. Qualitative content analysis guided coding and analysis. Patient ...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Increased peptidergic fibers as a potential cutaneous marker of pain in diabetic small fiber neuropathy
In this study, we performed a detailed skin biopsy analysis in a well-characterized group of DPN patients with primarily small fiber involvement, with and without pain, and in healthy controls and test for correlation between skin biopsy findings and pain intensity and quantitative sensory testing. We found that although there was no difference in intraepidermal nerve fiber density using protein gene product 9.5 between patients with and without pain, patients with pain had increased density of dermal peptidergic fibers containing substance P and calcitonin gene-related peptide compared with patients with painless DPN and ...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Evolution of doctor shopping for oxycodone in the 67 million inhabitants in France as a proxy for potential misuse or abuse
This study is a cross-sectional comparative analysis of doctor shopping based on all dispensings of oxycodone in France, in 2010 and 2016. Dispensings of oxycodone were extracted from the Système national des données de santé, which covers the 67 million inhabitants in France. Quantification of doctor shopping relies on an algorithm accounting for overlapping prescriptions, which is a proxy for potential misuse or abuse. The number of subjects who received oxycodone increased by 214% from 67,838 subjects in 2010 to 212,753 subjects in 2016, and the number of subjects with doctor-shopping behavior incre...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

When pain becomes uncontrollable: an experimental analysis of the impact of instructions on pain-control attempts
Abstract: Under some conditions, people persist in their attempts to control their pain even when no such control is possible. Theory suggests that such pain-control attempts arise from actual pain experiences. Across 3 experiments we examined how (1) losing control over pain and (2) instructions concerning pain, moderated pain-control attempts. In each experiment, participants completed a learning task. Before the task, one group of participants received instructions outlining a strategy through which they could control pain, whereas another group had to develop such a strategy through trial-and-error learning. During...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Antenatal pain, intimate partner violence, and maternal bonding disorder: data from the Japan Environment and Children's Study
This prospective study examined (1) whether antenatal pain is associated with postnatal maternal bonding disorder (MBD) through postnatal depression and (2) whether intimate partner violence (IPV) has a moderating effect on the association between antenatal pain and postnatal MBD. We analyzed 77,326 pregnancies of women who completed self-report questionnaires including the SF-8 bodily pain item, the Edinburgh Postnatal Depression Scale, the Mother-to-Infant Bonding Scale, and an assessment of IPV. We conducted a mediation analysis to assess whether postnatal depression mediated the association between antenatal pain and M...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Prolonged opioid use among opioid-naive individuals after prescription for nonspecific low back pain in the emergency department
Low back pain is a leading cause of disability globally. It is a common reason for presentation to the emergency department where opioids are commonly prescribed. This is a retrospective cohort study of opioid-naive adults with low back pain presenting to 1 of 4 emergency departments in Nova Scotia. We use routinely collected administrative clinical and drug-use data (July 2010-November 2017) to investigate the prevalence of prolonged opioid use and associated individual and prescription characteristics. In total, 23,559 eligible individuals presented with nonspecific low back pain, with 84.4% being opioid-naive. Our study...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Optimized acupuncture treatment (acupuncture and intradermal needling) for cervical spondylosis–related neck pain: a multicenter randomized controlled trial
Cervical spondylosis (CS)-related neck pain is difficult to treat because of its degenerative nature. The aim of this 9-center, single-blinded, randomized controlled trial was to evaluate the efficacy of optimized acupuncture for CS-related neck pain. Participants who met the inclusion criteria were randomized to optimized, shallow, and sham acupuncture groups (1:1:1). The primary outcome was the change from baseline in the Northwick Park Neck Pain Questionnaire score at week 4. Participants were followed up until week 16. Of the 896 randomized participants, 857 received ≥1 intervention session; 280, 286, and 291 receiv...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

No pain, still gain (of function): the relation between sensory profiles and the presence or absence of self-reported pain in a large multicenter cohort of patients with neuropathy
The pathophysiology of pain in neuropathy is complex and may be linked to sensory phenotypes. Quantitative sensory testing, a standardized method to evaluate sensory profiles in response to defined stimuli, assesses functional integrity of small and large nerve fiber afferents and central somatosensory pathways. It has revealed detailed insights into mechanisms of neuropathy, yet it remains unclear if pain directly affects sensory profiles. The main objective of this study was to investigate sensory profiles in patients with various neuropathic conditions, including polyneuropathy, mononeuropathy, and lesions to the centra...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Cell–cell interactions in joint pain: rheumatoid arthritis and osteoarthritis
No abstract available (Source: Pain)
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: PAIN Pictured Source Type: research

An unusual complication of quadriparesis after trigger point injection: a case report
Abstract: Quadriparesis after intramuscular trigger point injections for myofascial pain syndrome has been rarely reported in the literature. A 37-year-old male patient presented with myofascial pain syndrome and was given trigger point injections in trapezius muscles under ultrasound guidance. The patient noticed weakness in all the 4 limbs at approximately 12 hours after the procedure, which gradually progressed to functional quadriplegia at the time of presentation to the emergency department. On examination, he had quadriparesis with no sensory involvement and superficial reflexes were normal. MRI screening of the ...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Clinical Note Source Type: research

The STarT Back stratified care model for nonspecific low back pain: a model-based evaluation of long-term cost-effectiveness
This study therefore produces a de novo decision model of this stratified care approach for LBP management to estimate the long-term cost-effectiveness and address methodological concerns in LBP modelling. A cost-utility analysis from the National Health Service perspective compared stratified care with usual care in patients consulting in primary care with nonspecific LBP. A Markov state-transition model was constructed where patient prognosis over 10 years was dependent on physical function achieved at 12 months. Data from the clinical trial and implementation study provided short-term model parameters, with extrapolatio...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

The time course of attentional biases in pain: a meta-analysis of eye-tracking studies
Previous meta-analyses investigating attentional biases towards pain have used reaction time measures. Eye-tracking methods have been adopted to more directly and reliably assess biases, but this literature has not been synthesized in relation to pain. This meta-analysis aimed to investigate the nature and time course of attentional biases to pain-related stimuli in participants of all ages with and without chronic pain using eye-tracking studies and determine the role of task parameters and theoretically relevant moderators. After screening, 24 studies were included with a total sample of 1425 participants. Between-group ...
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

Relationship between psychological factors and spinal motor behaviour in low back pain: a systematic review and meta-analysis
In conclusion, the very small effect sizes found in the meta-analyses question the role of psychological factors as major causes of spinal movement avoidance in low back pain. Experimental studies with more specific and individualized measures of psychological factors, pain intensity, and spinal motor behaviour are recommended. (Source: Pain)
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Systematic Review and Meta-Analysis Source Type: research

Altered interoception and its role for the co-occurrence of chronic primary pain and mental health problems in children
No abstract available (Source: Pain)
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Topical Review Source Type: research

What can we learn from the failure of quantitative sensory testing?
No abstract available (Source: Pain)
Source: Pain - February 25, 2021 Category: Anesthesiology Tags: Commentary Source Type: research

Intergenerational transmission of chronic pain-related disability: the explanatory effects of depressive symptoms
Parents with chronic pain have a higher likelihood of having depression and anxiety and more often have children with these conditions. Depressive and anxious symptoms in children worsen pain-related disability and may be derived from exposure to their parents' symptoms. We assessed a model of intergenerational chronic pain-related disability that relies upon depressive and anxious symptoms of a mother and their child. Adolescents in grades 5 to 10 from 5 schools, and their mothers, completed standardized electronic questionnaires about pain. In maternal-offspring dyads (n = 1179), the mean offspring age was 12.7 years (SD...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Neural effects of placebo analgesia in fibromyalgia patients and healthy individuals
Placebo analgesia is hypothesized to involve top-down engagement of prefrontal regions that access endogenous pain inhibiting opioid pathways. Fibromyalgia (FM) patients have neuroanatomical and neurochemical alterations in pathways relevant to placebo analgesia. Thus, it remains unclear whether placebo analgesic mechanisms would differ in FM patients compared to healthy controls (HCs). Here, using placebo-analgesia-inducing paradigms that included verbal suggestions and conditioning manipulations, we examined whether behavioral and neural placebo analgesic responses differed between 32 FM patients and 46 age- and sex-matc...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Relationship of prosthesis ownership and phantom limb pain: results of a survey in 2383 limb amputees
Phantom limb pain (PLP) accounts for a significant reduction in quality of life and is difficult to treat. Prosthesis use has been shown to negatively covary with PLP. Recent research on body perception in amputees suggest that prosthesis ownership, defined as the extent to which a prosthesis is experienced as being part of the body rather than an artificial device foreign to the body, might interact with PLP. We used survey data from 2383 unilateral prosthesis-using upper-limb or lower-limb amputees and performed regression analyses to determine the relationship between prosthesis ownership and PLP. To test for specificit...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Cross-sectional study of psychosocial and pain-related variables among patients with chronic pain during a time of social distancing imposed by the coronavirus disease 2019 pandemic
The COVID-19 pandemic has had a tremendous impact, including on individuals with chronic pain. The social distancing policies necessary to slow the spread of SARS-CoV-2 have involved increased levels of social isolation. This cross-sectional survey study examined pain severity and interference among individuals with chronic pain during an early phase of social distancing mandates and identified characteristics of individuals who were most impacted. Approximately 4 to 8 weeks after social distancing mandates commenced in the state of Massachusetts, 150 patients with fibromyalgia, chronic spine, and postsurgical pain complet...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Nociceptive afferent phenotyping reveals that transient receptor potential ankyrin 1 promotes cold pain through neurogenic inflammation upstream of the neurotrophic factor receptor GFRα3 and the menthol receptor transient receptor potential melastatin 8
The proper detection and behavioral response to painfully cold temperatures is critical for avoiding potentially harmful tissue damage. Cold allodynia and hyperalgesia, pain associated with innocuous cooling and exaggerated pain with noxious cold, respectively, are common in patients with chronic pain. In peripheral somatosensory afferents, the ion channels transient receptor potential melastatin 8 (TRPM8) and transient receptor potential ankyrin 1 (TRPA1) are candidate receptors for innocuous and noxious cold temperatures, respectively. However, the role of TRPA1 as a cold sensor has remained controversial, and recent evi...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Metabolomic analysis coupled with extreme phenotype sampling identified that lysophosphatidylcholines are associated with multisite musculoskeletal pain
Musculoskeletal pain often occurs simultaneously at multiple anatomical sites. The aim of the study was to identify metabolic biomarkers for multisite musculoskeletal pain (MSMP) by metabolomics with an extreme phenotype sampling strategy. The study participants (n = 610) were derived from the Newfoundland Osteoarthritis Study. Musculoskeletal pain was assessed using a self-reported pain questionnaire where painful sites were circled on a manikin by participants and the total number of painful sites were calculated. Targeted metabolomic profiling on fasting plasma samples was performed using the Biocrates AbsoluteIDQ p180 ...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Differential actions of indomethacin: clinical relevance in headache
Nonsteroidal anti-inflammatory drugs, cyclooxygenase inhibitors, are used routinely in the treatment of primary headache disorders. Indomethacin is unique in its use in the diagnosis and treatment of hemicrania continua and paroxysmal hemicrania. The mechanism of this specific action is not fully understood, although an interaction with nitric oxide (NO) signaling pathways has been suggested. Trigeminovascular neurons were activated by dural electrical stimulation, systemic administration of an NO donor, or local microiontophoresis of L-glutamate. Using electrophysiological techniques, we subsequently recorded the activati...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

High-dose spinal cord stimulation for patients with failed back surgery syndrome: a multicenter effectiveness and prediction study
The use of high-dose spinal cord stimulation (HD-SCS) has increased drastically during the past few years, with positive results. However, there remains a deficit of real-world data of the effectiveness of HD-SCS. Therefore, the primary aim was to evaluate the effectiveness of HD-SCS in patients with failed back surgery syndrome (FBSS). The second aim was to develop a prediction model for a holistic responder. One hundred ninety-four patients were recruited to a multicenter real-world registry. Self-reporting outcome variables were evaluated at baseline (before SCS) and at 1, 3, and 12 months of HD-SCS implant. Outcome mea...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

A spider-venom peptide with multitarget activity on sodium and calcium channels alleviates chronic visceral pain in a model of irritable bowel syndrome
Chronic pain is a serious debilitating condition that affects ∼20% of the world's population. Currently available drugs fail to produce effective pain relief in many patients and have dose-limiting side effects. Several voltage-gated sodium (NaV) and calcium (CaV) channels are implicated in the etiology of chronic pain, particularly NaV1.1, NaV1.3, NaV1.7–NaV1.9, CaV2.2, and CaV3.2. Numerous NaV and CaV modulators have been described, but with few exceptions, they display poor potency and/or selectivity for pain-related channel subtypes. Here, we report the discovery and characterization of 2 novel tarantula-veno...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Double-blind, randomized, placebo-controlled crossover trial of alpha-lipoic acid for the treatment of fibromyalgia pain: the IMPALA trial
Fibromyalgia is a common and challenging chronic pain disorder with few, if any, highly effective and well-tolerated treatments. Alpha-lipoic acid (ALA) is a nonsedating antioxidant with evidence of efficacy in the treatment of symptomatic diabetic neuropathy that has not been evaluated in the setting of fibromyalgia treatment. Thus, we conducted a single-centre, proof-of-concept, randomized, placebo-controlled, crossover trial of ALA for the treatment of fibromyalgia. Twenty-seven participants were recruited, and 24 participants completed both treatment periods of the trial. The median maximal tolerated dose of ALA in thi...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Association between chronic pain and long-term cognitive decline in a population-based cohort of elderly participants
Chronic pain (CP) was associated with impaired cognitive performance in several cross-sectional studies conducted in older adults; however, fewer longitudinal studies assessed this link that remains still debated. With a prospective design, the present analysis was aimed at evaluating the relationship between CP and the change in several tests assessing memory, attention, verbal fluency, and processing speed. The study population was selected from the PAQUID study, a cohort of community dwellers aged 65 years and older; 693 subjects receiving a pain assessment were included. Chronic pain was evaluated using a questionnaire...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

A combination of pain indices based on momentary assessments can predict placebo response in patients with fibromyalgia syndrome
In conclusion, profiles of pain characteristics derived from baseline EMA may be useful for detecting patient subgroups with enhanced placebo responses that can diminish assay sensitivity in pain clinical trials. (Source: Pain)
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Effects of sex on placebo effects in chronic pain participants: a cross-sectional study
Sex-related differences can influence outcomes of randomized clinical trials and may jeopardize the effectiveness of pain management and other therapeutics. Thus, it is essential to understand the mechanistic and translational aspects of sex differences in placebo outcomes. Recently, studies in healthy participants have shed light on how sex-related placebo effects might influence outcomes, yet no research has been conducted in a patient population. Herein, we used a tripartite approach to evaluate the interaction of prior therapeutic experience (eg, conditioning), expectations, and placebo effects in 280 chronic (orofacia...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Acupuncture alleviates chronic pain and comorbid conditions in a mouse model of neuropathic pain: the involvement of DNA methylation in the prefrontal cortex
We examined whether acupuncture can restore epigenetic changes caused by chronic pain, and identified the underlying mechanisms in neuropathic pain mice. Acupuncture treatment for 6 months (3 days/week) improved mechanical/cold allodynia and the emotional/cognitive dysfunction caused by left partial sciatic nerve ligation (PSNL)-induced neuropathic pain. The effects of acupuncture were associated with global DNA methylation recovery in the prefrontal cortex (PFC). Analysis of DNA methylation patterns in PFC indicated that 1364 overlapping genes among 4442 and 4416 methylated genes in the PSNL vs sham and PSNL vs acupunctur...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research

Prevalence and predictors of burnout symptoms in multidisciplinary pain clinics: a mixed-methods study
Frequent exposure to patient distress is associated with a higher prevalence of clinician distress and burnout. Patients with chronic pain often present with high levels of emotional distress. The current study examined the prevalence of burnout symptoms among a multidisciplinary sample of pain clinicians in Australia, the relationship between clinician confidence managing emotions and symptoms of burnout, and clinicians' perspectives on sources of stress and wellbeing at work. One hundred seventy-six clinicians from 58 multidisciplinary pain clinics across Australia completed a survey including the 22-item Maslach Burnout...
Source: Pain - January 22, 2021 Category: Anesthesiology Tags: Research Paper Source Type: research