Pain: an overview

The protective role of life satisfaction, coping strategies and defense mechanisms on perceived stress due to COVID-19 emergency: A chained mediation model

The coronavirus disease-19 (COVID-19) pandemic represents a worldwide emergency, which may have harmful consequences on people’s mental health. Parallel to research focused on risk factors, it could be useful to investigate the factors that help to cope with such crises at an emotional level. Therefore, this study aimed to strengthen the role of variables that protect from subjective distress during the COVID-19 pandemic, explore the pathways between satisfaction with life and perceived stress, and consider the role of coping strategies and defense mechanisms in this relationship. A sample of 1102 Italian participants who were experiencing the COVID-19 lockdown measures (Mage = 34.91, SD = 11.91) completed an online survey in which the Ten Item Perceived Stress Scale, Satisfaction with Life Scale, Coping Orientation to Problems Experienced Inventory and Forty-Item Defense Style Questionnaire were included. The data were analyzed using Pearson’s r correlations and moderation analysis. A chained-mediation model showed that the relationship between life satisfaction and perceived stress is partially mediated by approach coping, positive attitude and mature defenses. This study contributes toward gaining a better understanding of a protective pathway for mental health outcomes during the COVID-19 pandemic. The findings could be useful from both a preventive and an intervention perspective.

Clinician-Patient Movement Synchrony Mediates Social Group Effects on Interpersonal Trust and Perceived Pain

Pain is an unfortunate consequence of many medical procedures, which in some patients becomes chronic and debilitating. Among the factors affecting medical pain, clinician-patient (C-P) similarity and nonverbal communication are particularly important for pain diagnosis and treatment. Participants (N = 66) were randomly assigned to clinician and patient roles and were grouped into C-P dyads. Clinicians administered painful stimuli to patients as an analogue of a painful medical procedure. We manipulated the perceived C-P similarity of each dyad using groups ostensibly based on shared beliefs and values, and each patient was tested twice: Once with a same group clinician (concordant, CC) and once with a clinician from the other group (discordant, DC). Movement synchrony was calculated as a marker of nonverbal communication. We tested whether movement synchrony mediated the effects of group concordance on patients' pain and trust in the clinician. Movement synchrony was higher in CC than DC dyads. Higher movement synchrony predicted reduced pain and increased trust in the clinician. Movement synchrony also formally mediated the group concordance effects on pain and trust. These findings increase our understanding of the role of nonverbal C-P communication on pain and related outcomes. Interpersonal synchrony may be associated with better pain outcomes, independent of the specific treatment provided. PERSPECTIVE: This article demonstrates that movement synchrony in C-P interactions is an unobtrusive measure related to their relationship quality, trust toward the clinician, and pain. These findings suggest that interpersonal synchrony may be associated with better patient outcomes, independent of the specific treatment provided.

Episodic future thinking reduces chronic pain severity: A proof of concept study

BACKGROUND

Chronic pain is a major public health challenge in the United States and around the world. Current treatments including opioid analgesics and cognitive behavioral therapy possess harmful side effects or limited efficacy, respectively. Chronic pain is associated with a variety of unhealthy behaviors including opioid misuse. Moreover, individuals who suffer from chronic pain exhibit excessive discounting of delayed rewards, suggesting a constricted temporal window of valuation. Reductions in the excessive discounting of delayed rewards has been achieved with Episodic Future Thinking (EFT; vividly imagining realistic future events). EFT has also been associated with reductions in a variety of unhealthy behaviors. In this study, the effects of EFT on delay discounting and levels of pain were investigated in individuals reporting chronic pain.

METHODS

Individuals reporting chronic pain (N = 250; 42.4 % female) were recruited through the Amazon Mechanical Turk platform. Measures of delay discounting and pain were collected at baseline and again after randomization to EFT (N = 128) or Control Episodic Thinking (CET) (N = 122).

RESULTS

EFT significantly reduced delay discounting relative to baseline (p < 0.001) and EFT reduced pain scores in a baseline dependent manner (p = 0.001) when compared to CET; that is, those with the greatest reports of pain experienced the greatest reduction. Furthermore the reduction in delay discounting fully mediated the reduction in pain.

CONCLUSIONS

These findings suggest that Episodic Future Thinking, by widening the temporal window, may reduce pain in those reporting chronic pain and therefore represents a potential novel therapeutic.

Somatic Symptom Perception From a Predictive Processing Perspective: An Empirical Test Using the Thermal Grill Illusion

OBJECTIVE

In a predictive processing perspective, symptom perceptions result from an integration of preexisting information in memory with sensory input. Physical symptoms can therefore reflect the relative predominance of either sensory input or preexisting information. In this study, we used the thermal grill illusion (TGI), which applies interlaced warm and cool temperatures to the skin to create a paradoxical heat-pain experience. Assuming that the TGI compared with single-temperature stimulation relies more importantly on an active integration process of the brain to create this paradoxical sensation, we tested the hypothesis whether a manipulation of the expectations during TGI would have more impact than during single-temperature stimulation.

METHODS

Sixty-four participants received different temperature combinations (16/16°C, 40/40°C, 16/40°C) with neutral, positive ("placebo"), and negative ("nocebo") instructions. Subjective stimulus intensity was rated, and neuroticism and absorption (openness to absorbing and self-altering experiences) served as potential moderating factors.

RESULTS

The TGI condition was rated highest. Overall, negative instructions increased (p < .001, d = 0.58), whereas positive instructions did not significantly change the TGI intensity perception (versus neutral; p = .144, d = 0.19). In the TGI condition, increased modulation of pain was observed with higher neuroticism (β = 0.33, p = .005) and absorption (β = 0.30, p = .010).

CONCLUSIONS

Whereas negative instructions induced a nocebo effect, no placebo effect emerged after positive instructions. The findings are in line with the predictive processing model of symptom perception for participants with higher levels of neuroticism and absorption.

The relationship between care dependency and pain in nursing home residents

CONTEXT

Pain is a common health problem experienced by up to 57 % of nursing home residents which has many negative side effects, including a reduced quality of life. Several studies have been carried out on the prevalence of pain and pain management. However, these study findings remain controversial.

OBJECTIVES

Therefore, the aim of this study was to compare care dependent and care independent nursing home residents with regard to their (1) pain prevalence and levels and (2) their pain management.

METHODS

This cross-sectional study is conducted annually in Austrian nursing homes. We measured pain prevalence and levels by asking questions about the pain experienced and pain level measured in the seven days prior to the interview, as well as the pain experienced at the time of this interview.

RESULTS

The study sample comprised 81.1 % of the 1528 residents of Austrian nursing homes. Overall, pain prevalence was higher in care dependent residents than in care independent residents. Care dependent residents experienced more often mild/moderate pain than care independent residents. Both, prevalence and levels of pain were not statistically significant different between the levels of care dependency. Care dependent residents who suffered from pain received a statistically significantly higher number of non-pharmacological interventions as compared to care independent residents who suffered from pain.

CONCLUSIONS

We identified a higher prevalence of pain among care dependent residents. Furthermore, the found differences in pain relief seem to be correlated with different degrees of care dependency, an aspect that requires further investigation.

How do mothers of adolescents with chronic pain experience their own quality of life?

BACKGROUND

Chronic pain is a major health problem globally with severe personal and economic consequences. Maternal chronic pain is associated with their children's pain. Family pain models and shared environmental aspects are important in the understanding of chronic pain among adolescents. Pain in itself impairs the quality of life (QoL). However, satisfaction in the aspects of health and functioning, social and economic, psychological, and family life will together constitute a person's subjective experience of QoL. On this background, we considered it important to gain an understanding of the QoL of mothers who have children with chronic pain. We aimed to gain a broader understanding of the QoL in mothers of children with chronic pain and to investigate how they managed their children's pain.

METHODS

This study had a qualitative design with face-to-face, in-depth interviews. The concept of QoL was used as a framework for developing a thematic, semi-structured interview guide. Eight mothers of adolescents with chronic pain (two boys and six girls) participated with signed consent.

RESULTS

Socio-economic difficulties and health complaints were common. Psychological stress, because of their children's physical pain and other stressful experiences such as bullying, dominated everyday life. Lack of predictability and of responsible involvement from the fathers' side increased the mothers' burden considerably. Experiencing not being helped by others such as health professionals resulted in feelings of helplessness.

CONCLUSIONS

These mothers had reduced QoL caused by their own health problems, concern for the child's well-being and lack of social support, which affected the child's upbringing and pain management. By improving these mothers' QoL, family-based shared pain management strategies could help in health promotion, leading to a more positive QoL circle. Elements of family and cognitive therapy could be applied when supporting the mothers and children and improving their QoL.

Antinociceptive effect of Lonchocarpus araripensis lectin: activation of L-arginine/NO/cGMP/K+ATP signaling pathway

OBJECTIVE AND DESIGN

The involvement of nitric oxide pathway in the antinociceptive activity of Lonchocarpus araripensis lectin (LAL) was investigated in the model of carragenan-induced hypernociception.

METHODS

Swiss mice received LAL (0.01-10 mg/kg; i.v.) 30 min before s.c. injection of carragenan in the paws. For the involvement of nociceptive pathways, animals were previously treated with the blockers: NOS (L-NAME, aminoguanidine, 7-nitroindazole); soluble guanylyl cyclase (ODQ); channels of ATP-dependent K⁺ (glibenclamide); L-type Ca²⁺ (nifedipine), or Ca²⁺-dependent Cl^- (niflumic acid). Participation of lectin domain was evaluated by injection of LAL associated with N-acetyl-glucosamine (GlcNAc). nNOS gene relative expression was evaluated in the paw tissues and nNOS immunostaining in dorsal root ganglia.

RESULTS

LAL at all doses inhibited carrageenan-induced hypernociception (4.12 ± 0.58 g), being maximal at 10 mg/kg (3 h: 59%), and reversed by GlcNAc. At this time, LAL effect was reversed by nifedipine (39%), niflumic acid (59%), L-NAME (59%), 7-nitroindazole (44%), ODQ (45%), and glibenclamide (34%), but was unaltered by aminoguanidine. LAL increased (95%) nNOS gene expression in mice paw tissues, but not its immunoexpression in the dorsal root ganglia.

CONCLUSION

The antinociceptive effect of Lonchocarpus araripensis lectin involves activation of the L-arginine/NO/GMPc/K⁺ATP pathway.

A Fatal Alliance between Microglia, Inflammasomes, and Central Pain

Microglia are the resident immune cells in the CNS, which survey the brain parenchyma for pathogens, initiate inflammatory responses, secrete inflammatory mediators, and phagocyte debris. Besides, they play a role in the regulation of brain ion homeostasis and in pruning synaptic contacts and thereby modulating neural networks. More recent work shows that microglia are embedded in brain response related to stress phenomena, the development of major depressive disorders, and pain-associated neural processing. The microglia phenotype varies between activated-toxic-neuroinflammatory to non-activated-protective-tissue remodeling, depending on the challenges and regulatory signals. Increased inflammatory reactions result from brain damage, such as stroke, encephalitis, as well as chronic dysfunctions, including stress and pain. The dimension of damage/toxic stimuli defines the amplitude of inflammation, ranging from an on-off event to low but continuous simmering to uncontrollable. Pain, either acute or chronic, involves inflammasome activation at the point of origin, the different relay stations, and the sensory and processing cortical areas. This short review aimed at identifying a sinister role of the microglia-inflammasome platform for the development and perpetuation of acute and chronic central pain and its association with changes in CNS physiology.

"Please mind the gap": A secondary analysis of discomfort and comfort in intensive care

AIMS AND OBJECTIVES

To explore in depth discomfort in intensive care as experienced by patients and attended to by critical care nurses.

BACKGROUND

Discomfort in illness is complex and persistent, and its alleviation is a challenge for nurses working in intensive care units (ICU). In previous studies, we showed that ICU patients described little actual pain but suffer from much discomfort. Critical care nurses had a systematic approach to the treatment of pain, but were more haphazard in dealing with other types of discomfort.

DESIGN

Secondary qualitative analysis of data from two previous exploratory studies.

METHODS

Content analysis was used on existing data from 28 interviews with ICU patients, and 16 field notes and interviews with critical care nurses. Kolcaba's Comfort Theory was applied for further analysis. The COREQ checklist was used.

RESULTS

Three themes, "Being deprived of a functioning body", "Being deprived of a functioning mind" and "Being deprived of integrity" characterised the discomfort experienced by ICU patients. The nurses appeared to attend to all areas of discomfort expressed by patients. In need of, and providing acknowledgment and alleviation became a common overarching theme. We identified a comfort gap caused by the discrepancy between the patients' needs and the nurses' achievements in fulfilling these needs.

CONCLUSIONS

A gap exists between ICU patients' comfort needs and nurses' achievements in fulfilling these, indicating that discomfort currently is an inevitable part of the critical illness trajectory. Increased knowledge about how the brain is affected in ICU patients and more systematic approaches to assessing comfort needs and enhancing comfort may support nurses in fulfilling patient needs and possibly diminish the existing comfort gap.

RELEVANCE FOR CLINICAL PRACTICE

An increased understanding of the complex experience of discomfort in ICU patients may bring about more systematic approaches to enhance comfort and direct for education and further research.

Effects of Music and Relaxation Suggestions on Experimental Pain

Pain is a significant public healthcare challenge. There is growing support for the use of music and suggestive techniques as adjuvant pain treatments. The purpose of this study was to (1) examine the effects of music listening combined with relaxation suggestions compared to music alone and silence on experimental pain, and (2) to explore the potential mechanisms of music-induced analgesia. Sixty-six healthy females were randomized to receive either (1) music plus relaxation suggestions, (2) music alone, or (3) silence. Pain and psychological constructs were assessed following two cold-pressor trials. Between-group comparisons indicated that music and suggestions for relaxation are not superior to music alone for pain. More research is needed to explore the effect of analgesic suggestions in combination with music to further investigate music's potential in clinical pain management.

Modulation of experimental facial pain via somatosensory stimuli targeting sensations of different valence

BACKGROUND

Knowledge of pain modulation from oro-facial somatosensory stimuli with different valence (pleasant-unpleasant) is limited.

OBJECTIVES

To investigate (a) the modulatory effects of painful, pleasant and unpleasant somatosensory stimuli on two models of experimental facial pain, (b) whether modulation could be changed by blocking peripheral nerves via application of a local anaesthetic, EMLA, or blocking endogenous opioid receptors via naltrexone and (c) whether pain ratings were significantly correlated with participant psychological profiles.

METHODS

Thirty-eight healthy women received experimental facial skin burning pain or jaw myalgia for four randomised sessions on different days. The painful region was stimulated with mechanical or thermal painful, pleasant, unpleasant and control stimuli, with ratings recorded before and during stimulation. Sessions differed in pre-treatment: EMLA/naltrexone/placebo tablet/cream.

RESULTS

Significant effects of thermal or mechanical stimuli (P < .017), but not session (P > .102), were found on pain ratings for both models. In myalgia, painful cold resulted in a greater reduction in pain ratings than unpleasant cold, pleasant cold, control and pleasant warmth (P < .004). Decreases in pain ratings from painful, unpleasant and pleasant mechanical stimuli were greater than control (P < .002). In burning pain, painful cold resulted in a greater reduction in pain ratings than all but one of the other thermal stimuli (P < .033). The pleasant mechanical stimulus reduced pain ratings more than all other mechanical stimuli (P ≤ .003). There were no significant correlations between pain and psychometrics.

CONCLUSION

Valence-targeted thermal and mechanical stimuli modulated experimental myalgia and skin burning pain (P < .017). Partially blocking peripheral afferents or opioid receptors did not affect modulation.

Pain-related anxiety promotes pronociceptive processes in Native Americans: bootstrapped mediation analyses from the Oklahoma Study of Native American Pain Risk

INTRODUCTION

Evidence suggests Native Americans (NAs) experience higher rates of chronic pain than the general US population, but the mechanisms contributing to this disparity are poorly understood. Recently, we conducted a study of healthy, pain-free NAs (n = 155), and non-Hispanic whites (NHWs, n = 150) to address this issue and found little evidence that NAs and NHWs differ in pain processing (assessed from multiple quantitative sensory tests). However, NAs reported higher levels of pain-related anxiety during many of the tasks.

OBJECTIVE

The current study is a secondary analysis of those data to examine whether pain-related anxiety could promote pronociceptive processes in NAs to put them at chronic pain risk.

METHODS

Bootstrapped indirect effect tests were conducted to examine whether pain-related anxiety mediated the relationships between race (NHW vs NA) and measures of pain tolerance (electric, heat, ischemia, and cold pressor), temporal summation of pain and the nociceptive flexion reflex (NFR), and conditioned pain modulation of pain/NFR.

RESULTS

Pain-related anxiety mediated the relationships between NA race and pain tolerance and conditioned pain modulation of NFR. Exploratory analyses failed to show that race moderated relationships between pain-related anxiety and pain outcomes.

CONCLUSION

These findings imply that pain-related anxiety is not a unique mechanism of pain risk for NAs, but that the greater tendency to experience pain-related anxiety by NAs impairs their ability to engage descending inhibition of spinal nociception and decreases their pain tolerance (more so than NHWs). Thus, pain-related anxiety may promote pronociceptive processes in NAs to place them at risk for future chronic pain.

Comparison of Core Stabilisation Exercise and Proprioceptive Neuromuscular Facilitation Training on Pain-related and Neuromuscular Response Outcomes for Chronic Low Back Pain: A Randomised Controlled Trial

Background

Existing literature offers little guidance for therapists who provide core stabilisation exercise (CSE) and proprioceptive neuromuscular facilitation (PNF) training to treat chronic low back pain (CLBP). Studies conducting a head-to-head comparison of CSE and PNF training for CLBP are needed.

Objective

To compare the effects of CSE and PNF training on pain-related outcomes and trunk muscle activity in CLBP patients.

Methods

Forty-five CLBP patients, ranging from 18 to 50 years of age, were randomly divided and assigned to either a four-week CSE, four-week PNF training, or control group. Pain-related outcomes, including pain intensity, functional disability and patient satisfaction, as well as superficial and deep trunk muscle activity were assessed before and after the four-week intervention, and at a three-month follow-up.

Results

Compared to the control group, those in the CSE and PNF training groups showed significant improvements in all pain-related outcomes after the four-week intervention and at three-month follow-up (P < 0.01). Following the four-week intervention, both CSE and PNF training groups demonstrated significant improvement in deep trunk muscle activity, including the transversus abdominis (TrA) and superficial fibres of lumbar multifidus (LM), compared to the control group (P < 0.05).

Conclusion

Four-week CSE and PNF training provided short-term and long-term effects on pain-related outcomes, along with increased deep trunk muscle activity in CLBP patients.

Novel Characterization Of Thermal Temporal Summation Response By Analysis Of Continuous Pain Vs Time Curves And Exploratory Modeling

Background

Temporal summation (TS) refers to the increased perception of pain with repetitive noxious stimuli. While thermal TS is generally considered a behavioral correlate of spinal windup, noxious heat pulses also trigger additional sensory processes which were modeled in this study.

Methods

Nineteen healthy volunteers (9 females, mean age 29.2, SD 10.5) underwent two identical TS experiments, spaced a week apart. The TS paradigm consisted of 10 identical heat pulses with individualized temperatures at the thenar eminence (0.5Hz). We extracted 3 features from continuous TS response curves: Lag, time to first feel pain; Slope, the rate of pain increase between the first and most painful heat pulse; and Delta, the maximum drop in pain after peak pain is reached. We then examined the within-individual stability of these features, followed by the Pearson’s correlations among these features and between the features and negative affect.

Results

All 3 features were stable over 1 week. Lag and Delta were negatively correlated (r = −0.5, p = 0.042). Slope did not correlate with Lag or Delta, but strongly correlated with a traditional TS measure, first pulse pain and peak pain difference (r = 0.91, p < 0.0001). Negative affects such as trait and state anxiety were negatively correlated with baseline (r = −0.49, p = 0.031) and peak stimulating temperature (r = −0.48, p = 0.039), respectively, suggesting an association between anxiety and greater pain sensitivity.

Conclusion

We were able to decouple spinal windup from other perceptual processes generated by phasic thermal TS paradigms and demonstrate temporal stability of these curve features. These curve features may help better characterize the complex sensory response to noxious heat pulses and serve as biomarkers to profile patients with chronic pain.

Construction And Analysis Of The Time-Evolving Pain-Related Brain Network Using Literature Mining

Purpose

We aimed to quantitatively investigate how the neuroscience field developed over time in terms of its concept on how pain is represented in the brain and compare the research trends of pain with those of mental disorders through literature mining of accumulated published articles.

Methods

The abstracts and publication years of 137,525 pain-related articles were retrieved from the PubMed database. We defined 22 pain-related brain regions that appeared more than 100 times in the retrieved abstracts. Time-evolving networks of pain-related brain regions were constructed using the co-occurrence frequency. The state-space model was implemented to capture the trend patterns of the pain-related brain regions and the patterns were compared with those of mental disorders.

Results

The number of pain-related abstracts including brain areas steadily increased; however, the relative frequency of each brain region showed different patterns. According to the chronological patterns of relative frequencies, pain-related brain regions were clustered into three groups: rising, falling, and consistent. The network of pain-related brain regions extended over time from localized regions (mainly including brain stem and diencephalon) to wider cortical/subcortical regions. In the state-space model, the relative frequency trajectory of pain-related brain regions gradually became closer to that of mental disorder-related brain regions.

Conclusion

Temporal changes of pain-related brain regions in the abstracts indicate that emotional/cognitive aspects of pain have been gradually emphasized. The networks of pain-related brain regions imply perspective changes on pain from the simple percept to the multidimensional experience. Based on the notable occurrence patterns of the cerebellum and motor cortex, we suggest that motor-related areas will be actively explored in pain studies.

Changing the Narrative in Diagnosis and Management of Pain in the Sacroiliac Joint Area

The sacroiliac joint (SIJ) is often considered to be involved when people present for care with low back pain where SIJ is located. However, determining why the pain has arisen can be challenging, especially in the absence of a specific cause such as pregnancy, disease, or trauma, when the SIJ might be identified as a source of symptoms with the help of manual clinical tests. Nonspecific SIJ-related pain is commonly suggested to be causally associated with movement problems in the SIJ(s)-a diagnosis traditionally derived from manual assessment of movements of the SIJ complex. Management choices often consist of patient education, manual treatment, and exercise. Although some elements of management are consistent with guidelines, this Perspective article argues that the assumptions on which these diagnoses and treatments are based are problematic, particularly if they reinforce unhelpful, pathoanatomical beliefs. This article reviews the evidence regarding the clinical detection and diagnosis of SIJ movement dysfunction. In particular, it questions the continued use of assessing movement dysfunction despite mounting evidence undermining the biological plausibility and subsequent treatment paradigms based on such diagnoses. Clinicians are encouraged to align their assessment methods and explanatory models with contemporary science to reduce the risk of their diagnoses and choice of intervention negatively affecting clinical outcomes.

Pain in Neonates: A Concept Analysis

Context

The term pain in neonates is emerged in recent decades. However, studies on pain in neonates are still limited and have various indicators. In addition, the term pain still often overlaps with stress in various studies and clinical circumstances. The concepts of pain and stress in the neonates need to be clarified to be better understood and then applied to improve neonates’ quality of life. Therefore, the current study aimed at clarifying the concept of pain in neonates.

Evidence Acquisition

The current study employed the concept analysis approach developed by Walker and Avant. The authors reviewed articles from JSTOR, ScienceDirect, Proquest, Sage, Cochrane, and Springer databases from 1980 to 2016 using keywords pain, stress, neonatal, neonates, and quality of life.

Results

Pain had attributes such as tissue damage, physiological changes, metabolic changes, and behavioral changes. Stress had attributes such as physiological changes, metabolic changes, and behavioral changes.

Conclusions

Attributes of pain and stress have similarities and differences. The main difference is the stimulus that induces a response. Pain has an attribute of tissue damage, whereas stress is not always due to tissue damage. The attributes of physical, metabolic, and behavioral changes between pain and stress are similar.

Cannabinoids versus placebo or no intervention for pain: protocol for a systematic review with meta-analysis and trial sequential analysis

INTRODUCTION

Pain is a frequent clinical symptom with significant impact on the patient's well-being. Therefore, adequate pain management is of utmost importance. While cannabinoids have become a more popular alternative to traditional types of pain medication among patients, the quality of evidence supporting the use of cannabinoids has been questioned. The beneficial and harmful effects of cannabinoids in patients with pain is unknown. Accordingly, we aim to assess the efficacy, tolerability and safety of cannabinoids (herbal, plant-derived extracts and synthetic) compared with placebo or no intervention for any type of pain.

METHODS AND ANALYSES

We will conduct a systematic review of randomised clinical trials with meta-analysis and Trial Sequential Analysis to assess the beneficial and harmful effects of cannabinoids in any dose, formulation and duration. We will accept placebo or no treatment as control interventions. We will include participants with any type of pain (acute and chronic pain, cancer-related pain, headache, neuropathic pain or any other types of pain). We will systematically search The Cochrane Library, MEDLINE, Embase, Science Citation Index and BIOSIS for relevant literature. We will follow the recommendations by Cochrane and the Preferred Reporting Items for Systematic Review and Meta-Analysis statement. The risk of systematic errors (bias) and random errors (play of chance) will be assessed. The overall certainty of evidence will be evaluated using the Grading of Recommendations Assessment, Development and Evaluation approach.

ETHICS AND DISSEMINATION

Ethical approval is not a requirement since no primary data will be collected. The findings of this systematic review will be submitted for peer-reviewed publication and disseminated in national and international conferences.

DISCUSSION

Although cannabinoids are now being used to manage different pain conditions, the evidence for the clinical effects are unclear. The present review will systematically assess the current evidence for the benefits and harms of cannabinoids to inform practice and future research.

The use of posture-correcting shirts for managing musculoskeletal pain is not supported by current evidence - a scoping review of the literature

BACKGROUND AND AIMS

The concept of bad posture being a dominant driver of pain is commonly held belief in the society. This may explain the significant attention supportive clothing such as posture-correcting shirts has recently gained in Scandinavia and the USA. The aim of this scoping review was to present an overview and synthesis of the available evidence for the use of posture-correcting shirts aimed at reducing pain or postural discomfort and optimising function/posture.

METHODS

A systematic search was conducted for literature investigating the effect of posture-correcting shirts on musculoskeletal pain or function. PubMed, Embase, CINAHL, PEDro and the Cochrane Library were searched for relevant literature. Results of the searches were evaluated by two independent reviewers in three separate steps based on title, abstract and full text. For data synthesis, the population, intervention, comparator and outcome were extracted. The quality of the literature was evaluated using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and the risk of bias was assessed using the Risk Of Bias In Non-randomized Studies - of Interventions (ROBINS-I) assessment tool or the RoB 2.0 tool for individually randomized, parallel group trials. The overall confidence in the literature was determined using the Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

A total of 136 articles were identified and six of these were included in the review. These studies were heterogeneous with regards to aims, outcomes and methods, presenting contrasting results. The overall findings were that posture-correcting shirts change posture and subjectively have a positive effect on discomfort, energy levels and productivity. The quality of the included literature was poor to fair with only one study being of good quality. The risk of bias was serious or critical for the included studies. Overall, this resulted in very low confidence in available evidence. An important limitation of all studies was that they were conducted in pain-free individuals.

CONCLUSIONS

The contrasting findings and the low quality of current literature, questions the intended effect of posture-correcting shirts and whether the changes it creates are in fact useful for clinical practice. Moreover, the findings are contrasted by the available evidence regarding posture and pain with a particular focus on whether this management strategy may have a detrimental effect on people living with musculoskeletal pain. A major limitation to the existing literature on the effect of posture-correcting shirts is that no studies have investigated their effect in clinical populations.

IMPLICATIONS

Based on the available literature and the major limitation of no studies investigating clinical populations, there is no good quality evidence to support recommendation of posture-correcting shirts as a management strategy for musculoskeletal pain. Promotion of this product may reinforce the inaccurate and unhelpful message that poor posture leads to pain. The efficacy of such garments should be tested in clinical populations and not only in pain-free individuals, to assess whether there is any meaningful benefit of this management approach. Until then, the use of posture-correcting shirts for musculoskeletal pain is not supported by current evidence.

Sensory, Affective, and Catastrophizing Reactions to Multiple Stimulus Modalities: Results from the Oklahoma Study of Native American Pain Risk

Native Americans (NAs) have a higher prevalence of chronic pain than any other U.S. racial/ethnic group; however, little is known about the mechanisms for this pain disparity. This study used quantitative sensory testing to assess pain experience in healthy, pain-free adults (n = 137 NAs (87 female), n = 145 non-Hispanic whites (NHW; 68 female)) after painful electric, heat, cold, ischemic, and pressure stimuli. After each stimulus, ratings of pain intensity, sensory pain, affective pain, pain-related anxiety, and situation-specific pain catastrophizing were assessed. The results suggested that NAs reported greater sensory pain in response to suprathreshold electric and heat stimuli, greater pain-related anxiety to heat and ischemic stimuli, and more catastrophic thoughts in response to electric and heat stimuli. Sex differences were also noted; however, with the exception of catastrophic thoughts to cold, these finding were not moderated by race/ethnicity. Together, findings suggest NAs experience heightened sensory, anxiety, and catastrophizing reactions to painful stimuli. This could place NAs at risk for future chronic pain and could ultimately lead to a vicious cycle that maintains pain (eg, pain → anxiety/catastrophizing → pain). PERSPECTIVE: NAs experienced heightened sensory, anxiety, and catastrophizing reactions in response to multiple pain stimuli. Given the potential for anxiety and catastrophic thoughts to amplify pain, this characteristic may place them at risk for pain disorders and could lead to a vicious cycle that maintains pain.

Truncal blocks and teenager postoperative pain perception after laparoscopic surgical procedures

Introduction:

The prevalence of moderate to severe pain is high in hospitalized teenage patients admitted to surgical services.

Objectives:

The aims of this study were to determine (1) the preoperative and postoperative factors influencing teenager postoperative pain perception; and (2) suffering, defined as the patient's anxiety, pain catastrophizing thoughts, and mood.

Methods:

Data were collected from medical records and from 2 medical interviews at the time of enrollment and postoperative day 1. Stepwise linear regression was conducted to assess variables that predicted teenagers' pain scores and suffering.

Results:

Two hundred two patients (mean age = 13.8 years, SD = 1.9), 56.4% females, scheduled for laparoscopic surgical procedures completed the study. The variables found to be significant predictors of pain response in teenagers were pain on the day of surgery (6.81, 95% confidence interval [CI] = 0.08–13.55, P = 0.05) and use of regional anesthesia (single-injection rectus sheath, transversus abdominis plane, and paravertebral nerve blocks) (−6.58, 95% CI = −12.87 to −0.30, P = 0.04). The use of regional anesthesia was found to predict mood responses (all patients: 2.60, 95% CI = 0.68–4.52, P = 0.01; girls: 3.45, 95% CI = 0.96–5.93, P = 0.01; 14–17-year-old teens: 2.77, 95% CI = 0.44–5.10, P = 0.02) and to negatively predict catastrophic thoughts among all patients as a group (−4.35, 95% CI = −7.51 to −1.19, P = 0.01) and among 14- to 17-year-old teens (−5.17, 95% CI = −9.44 to −0.90, P = 0.02).

Conclusion:

A comprehensive pain approach that includes truncal blocks may improve teenagers' postoperative pain control after laparoscopic surgeries.

Motivational Non-directive Resonance Breathing as a Treatment for Chronic Widespread Pain

Chronic widespread pain (CWP) is one of the most difficult pain conditions to treat due to an unknown etiology and a lack of innovative treatment design and effectiveness. Based upon preliminary findings within the fields of motivational psychology, integrative neuroscience, diaphragmatic breathing, and vagal nerve stimulation, we propose a new treatment intervention, motivational non-directive (ND) resonance breathing, as a means of reducing pain and suffering in patients with CWP. Motivational ND resonance breathing provides patients with a noninvasive means of potentially modulating five psychophysiological mechanisms imperative for endogenously treating pain and increasing overall quality of life.

The point of pain in head and neck cancer

Head and neck cancer (HNC) can have a devastating impact on patient's lives as both disease and treatment may affect the ability to speak, swallow and breathe. These conditions limit the oral intake of food and drugs, reduce social functioning and impact on patient's quality of life. Up to 80% of patients suffering from HNC have pain due to the spread of the primary tumor, because of consequences of surgery, or by developing oral mucositis, dysphagia or neuropathy as toxic side effects of radiotherapy, chemotherapy or both. All healthcare professionals caring for HNC patients should assess palliative and supportive care needs in initial treatment planning and throughout the disease, with awareness when specialist palliative care expertise is needed. This paper focuses on assessment, characterizations and clinical management of pain in advanced HNC patients undergoing surgery, chemotherapy and radiotherapy, also underlining the importance of symptom assessment in HNC survivors and the need of clinical research in this field.

Computational and pharmacological investigation of novel 1,5-diaryl-1,4-pentadien-3-one derivatives for analgesic, anti-inflammatory and anticancer potential

Objective(s):

The novel 1,5-diaryl-1,4-pentadien-3-one derivatives were studied for analgesic, anti-inflammatory and anticancer potential to establish their role in pain, inflammatory disorders and cancer.

Materials and Methods:

Two 1,5- diaryl-1,4-pentadien-3-one derivatives: (1E,4E)- 5-(4-fluoro phenyl)-1-(4-methoxyphenyl)- 2-methylpenta-1,4-dien-3-one (A2K2A17) and (1E,4E)-5-(4-nitrophenyl)-1-(4-nitrophenyl)-2-ethylhexa-1,4-dien-3-one (A11K3A11) were synthesized and characterized via 1H NMR and 13C NMR techniques. Molecular docking, anti-inflammatory, analgesic and anticancer activities were performed using Auto Doc Vina, carrageenan mediated paw edema and formalin induced chronic inflammation, acetic acid induced writhings and hotplate assay and brine-shrimp lethality assay.

Results:

A2K2A17 and A11K3A11 showed high computational affinities (binding energy > -9.0 Kcal/mol) against COX-1, kappa receptor and braf kinase domain. A2K2A17 and A11K3A11 exhibited moderate docking affinities (binding energy > -8.0 Kcal/mol) against COX-2, human capsaicin receptor, tumor necrosis factor, lipoxygenase, colony stimulating factor, delta receptor, cyclin dependent protein kinase-2, mitogen activated kinase, mu receptor and kit kinase domain. A2K2A17 and A11K3A11 possess low docking affinities (binding energy > -7.0 Kcal/mol) against purinoceptor, platelets-derived growth Factor-1 and vascular-endothelial growth factor. In analgesic activity, A2K2A17 (1-30 mg/kg) and A11K3A11 (1-10 mg/kg) decreased acetic acid induced writhes and prolonged the latency time (P<0.01, P<0.001 vs saline group) respectively. A2K2A17 (10-30 mg/kg) and A11K3A11 (1-10 mg/kg) reduced carrageenan as well as formalin mediated edema (P<0.01, P<0.001). A2K2A17 found effective for cytotoxicity assay with LC₅₀ value 1.5 µg/ml.

Conclusion:

The in silico, in vitro and in vivo studies on A2K2A17 and A11K3A11 reports their computational binding affinities against targets as well as the analgesic, anti-inflammatory and the anticancer effects.

Low-dose intravenous ketamine versus intravenous ketorolac in pain control in patients with acute renal colic in an emergency setting: a double-blind randomized clinical trial

BACKGROUND

This study was conducted to compare the effectiveness of low-dose ketamine versus ketorolac in pain control in patients with acute renal colic presenting to the emergency department (ED).

METHODS

This is a double-blind randomized clinical trial. The initial pain severity was assessed using the numerical rating scale (NRS). Then, ketamine or ketorolac was administered intravenously at a dose of 0.6 mg/kg and 30 mg respectively. The pain severity and adverse drug reactions were recorded 5, 15, 30, 60, and 120 min thereafter.

RESULTS

The data of 62 subjects in the ketamine group and 64 patients in the ketorolac group were analyzed. The mean age of the patients was 34.2 ± 9.9 and 37.9 ± 10.6 years in the ketamine and ketorolac group, respectively. There was no significant difference in the mean NRS scores at each time point, except for the 5 min, between the two groups. Despite a marked decrease in pain severity in the ketamine group from drug administration at the 5 min, a slight increase in pain was observed from the 5 min to the 15 min. The rate of adverse drug reactions, including dizziness (P = 0.001), agitation (P = 0.002), increased systolic blood pressure (> 140 mmHg), and diastolic blood pressure (> 90 mmHg) was higher in the ketamine group.

CONCLUSIONS

Low dose ketamine is as effective as ketorolac in pain management in patients with renal colic presenting to the ED. However, it is associated with a higher rate of adverse drug reactions.

Social hierarchy of pain and its connection to the memory of previously suffered pain

Background

Pain is a perception conditioned both by the painful experience and by each society's collective imagination. The general objective of the project which this work forms part of it was to discover what citizens think about different aspects of this complex experience. More precisely, this paper's objective is to get to know which is the worst pain that can be suffered according to Spaniards and what determines that hierarchy, bearing in mind that this work has chosen a broad definition of pain, including pains of different origins, namely, physical, psychological, and emotional pain.

Materials and methods

The data from the CIS 3137 study "Social perceptions of pain" have been used, which is a survey module designed by the Institute of Advanced Social Studies (IESA) of the Spanish National Research Council (CSIC). A hierarchical multiple factor analysis has been performed, using the SPSS statistical analysis software, where the dependent variable is the citizen's opinion on which is the worst pain that can be suffered, recoded according to the origin of pain (physical, psychological, and emotional pain). Sociodemographic variables and variables linked to the experience of pain have been included as independent variables.

Results and conclusion

Although the most frequent pains among Spanish citizens are those of a physical origin, especially those linked to musculoskeletal problems and pains of an orofacial origin, when they are asked about the worst pain a person can suffer, they do not mention this type of pain, but those of an emotional origin. It has also been possible to confirm that the pain that citizens refer to when asked about the worst pain that can be suffered, and, therefore, the hierarchy of pain held by Spanish citizens as a group, is conditioned, although not determined, by the pain that has previously been suffered - by one's own experience of pain.

Short-term effect of a chronic pain self-management intervention delivered by an easily accessible primary healthcare service: a randomised controlled trial

OBJECTIVES

To investigate the effects on persons with chronic pain after 3 months of a group-based chronic pain self-management course compared with a drop-in, low-impact outdoor physical group activity on patient activation and a range of secondary outcomes.

DESIGN

An open, pragmatic, parallel group randomised controlled trial. Analyses were performed using a two-level linear mixed model.

SETTING

An easily accessible healthcare service provided by Norwegian public primary healthcare.

PARTICIPANTS

A total of 121 participants with self-reported chronic pain for 3 months or more were randomised with 60 participants placed in the intervention group and 61 placed in the control group (mean age 53 years, 88% women, 63% pain for 10 years or more).

INTERVENTIONS

The intervention group was offered a group-based chronic pain self-management course with 2.5-hour weekly sessions for a period of 6 weeks. The sessions consisted of education, movement exercises and emphasised group discussions. The control group was offered a low-impact outdoor group physical activity in 1-hour weekly sessions that consisted of walking and simple strength exercises for a period of 6 weeks.

MAIN OUTCOMES

The primary outcome was patient activation assessed using the Patient Activation Measure. Secondary outcomes measured included assessments of pain, anxiety and depression, pain self-efficacy, sense of coherence, health-related quality of life, well-being and the 30 s chair to stand test.

RESULTS

There was no effect after 3 months of the group-based chronic pain self-management course compared with the control group for the primary outcome, patient activation (estimated mean difference: -0.5, 95% CI -4.8 to 3.7, p=0.802).

CONCLUSIONS

There was no support for the self-management course having a better effect after 3 months than a low-impact outdoor physical activity offered the control group.

TRIAL REGISTRATION NUMBER

NCT02531282; Results.

Synthesis, characterization, molecular docking, analgesic, antiplatelet and anticoagulant effects of dibenzylidene ketone derivatives

In this study dibenzylidene ketone derivatives (2E,5E)-2-(4-methoxybenzylidene)-5-(4-nitrobenzylidene) cyclopentanone (AK-1a) and (1E,4E)-4-(4-nitrobenzylidene)-1-(4-nitrophenyl) oct-1-en-3-one (AK-2a) were newly synthesized, inspired from curcuminoids natural origin. Novel scheme was used for synthesis of AK-1a and AK-2a. The synthesized compounds were characterized by spectroscopic techniques. AK-1a and AK-2a showed high computational affinities (E-value > - 9.0 kcal/mol) against cyclooxygenase-1, cyclooxygenase-2, proteinase-activated receptor 1 and vitamin K epoxide reductase. AK-1a and AK-2a showed moderate docking affinities (E-value > - 8.0 kcal/mol) against mu receptor, kappa receptor, delta receptor, human capsaicin receptor, glycoprotein IIb/IIIa, prostacyclin receptor I2, antithrombin-III, factor-II and factor-X. AK-1a and AK-2a showed lower affinities (E-value > - 7.0 kcal/mol) against purinoceptor-3, glycoprotein-VI and purinergic receptor P2Y12. In analgesic activity, AK-1a and AK-2a decreased numbers of acetic acid-induced writhes (P < 0.001 vs. saline group) in mice. AK-1a and AK-2a significantly prolonged the latency time of mice (P < 0.05, P < 0.01 and P < 0.001 vs. saline group) in hotplate assay. AK-1a and AK-2a inhibited arachidonic acid and adenosine diphosphate induced platelet aggregation with IC50 values of 65.2, 37.7, 750.4 and 422 µM respectively. At 30, 100, 300 and 1000 µM concentrations, AK-1a and AK-2a increased plasma recalcification time (P < 0.001 and P < 0.001 vs. saline group) respectively. At 100, 300 and 1000 µg/kg doses, AK-1a and AK-2a effectively prolonged bleeding time (P < 0.001 and P < 0.01 vs. saline group) respectively. Thus in-silico, in-vitro and in-vivo investigation of AK-1a and AK-2a reports their analgesic, antiplatelet and anticoagulant actions.

The dynamics of stress: a longitudinal MRI study of rat brain structure and connectome

Stress is a well-established trigger for a number of neuropsychiatric disorders, as it alters both structure and function of several brain regions and its networks. Herein, we conduct a longitudinal neuroimaging study to assess how a chronic unpredictable stress protocol impacts the structure of the rat brain and its functional connectome in both high and low responders to stress. Our results reveal the changes that stress triggers in the brain, with structural atrophy affecting key regions such as the prelimbic, cingulate, insular and retrosplenial, somatosensory, motor, auditory and perirhinal/entorhinal cortices, the hippocampus, the dorsomedial striatum, nucleus accumbens, the septum, the bed nucleus of the stria terminalis, the thalamus and several brain stem nuclei. These structural changes are associated with increasing functional connectivity within a network composed by these regions. Moreover, using a clustering based on endocrine and behavioural outcomes, animals were classified as high and low responders to stress. We reveal that susceptible animals (high responders) develop local atrophy of the ventral tegmental area and an increase in functional connectivity between this area and the thalamus, further spreading to other areas that link the cognitive system with the fight-or-flight system. Through a longitudinal approach we were able to establish two distinct patterns, with functional changes occurring during the exposure to stress, but with an inflection point after the first week of stress when more prominent changes were seen. Finally, our study revealed differences in functional connectivity in a brainstem-limbic network that distinguishes resistant and susceptible responders before any exposure to stress, providing the first potential imaging-based predictive biomarkers of an individual's resilience/vulnerability to stressful conditions.

Grading facial expression is a sensitive means to detect grimace differences in orofacial pain in a rat model

Although pre-clinical models of pain are useful for defining relationships between biological mechanisms and pain, common methods testing peripheral sensitivity do not translate to the human pain experience. Facial grimace scales evaluate affective pain levels in rodent models by capturing and scoring spontaneous facial expression. But, the Rat Grimace Scale (RGS) has not assessed the common disorder of temporomandibular joint (TMJ) pain. A rat model of TMJ pain induced by jaw loading (1 hr/day for 7 days) was used to investigate the time course of RGS scores and compare them between different loading magnitudes with distinct peripheral sensitivity profiles (0N–no sensitivity, 2N–acute sensitivity, 3.5N–persistent sensitivity). In the 3.5N group, RGS is elevated over baseline during the loading period and one day after loading and is correlated with peripheral sensitivity (ρ = −0.48, p = 0.002). However, RGS is not elevated later when that group exhibits peripheral sensitivity and moderate TMJ condylar cartilage degeneration. Acutely, RGS is elevated in the 3.5N loading group over the other loading groups (p < 0.001). These findings suggest that RGS is an effective tool for detecting spontaneous TMJ pain and that spontaneous pain is detectable in rats that develop persistent TMJ sensitivity, but not in rats with acute resolving sensitivity.

Behavioral interventions in health neuroscience

Many chronic health concerns (obesity, addiction, stress, chronic pain, and depression) have garnered recent attention for their increasing frequency, intractability, and serious health consequences. Because they are often difficult to treat and there are not always effective pharmacological treatments, many patients are pursuing behavioral interventions for these conditions. Experimental behavioral intervention studies have shown some efficacy for health, but the mechanisms for these treatments are not well understood. Health neuroscience is a burgeoning field that seeks to link neural function and structure with physical and mental health. Through this lens, initial studies have begun to investigate how behavioral interventions modulate neural function in ways that lead to improvements in health markers and outcomes. Here, we provide a review of these studies in terms of how they modulate key neurobiological systems, and how modulation of these systems relates to physical health and disease outcomes. We conclude with discussion of opportunities for future research in this promising area of study.

Prevalence, localization, perception and management of pain in dance: an overview

Background and aims

Pain is a highly complex bio-psychosocial phenomenon that may present a (potential) health risk and either occurs as a warning sign or a symptom of injury. It cannot be ruled out that these rising or changing requirements in dance of all styles, are reflected in health-related outcomes such as pain. The aim of this narrative review article is to outline an overview of prevalence and localization, concepts of performance pain and injury pain, pain perception and pain management in dance. At that consequences of pain and influencing factors focusing on different dance styles or forms of professionalism are discussed.

Methods

The databases CINAHL, Cochrane, Google Scholar, Medline, MeSH and Web of Science were screened for relevant articles.

Results

Pain prevalence in dance is very high. Pain localizations can be related to high dance-specific mechanical stress on the musculoskeletal system. Depending on the pain characteristics, dancers perceive pain as “positive” (performance pain) or “negative” (injury pain). Concerning pain attitudes and management, dancers show an increasing pain tolerance. Pain seems to be accepted as a necessity, often ignored and dancing is continued despite pain.

Conclusions

The findings of this article suggest that occurrence of pain, pain perception, coping with pain and pain history appear to be connected to dance-specific mechanical stress as well as to socialization in dance culture. In dance, effects of pain on health seem to be associated with characteristics of pain and pain behavior.

Implications

The results highlight the high relevance of pain in dance and the need to take into account preventive as well as rehabilitative measures.

A Proposed Molecular Mechanism for Physical Analgesia in Chronic Pain

Although pain is indispensable for survival, chronic pain places a heavy burden on humans. As the efficacy of opioid treatment is limited, the development of alternative methods of pain relief without medication is desirable. Recently, we have developed a novel method of physical analgesia using an adhesive “pyramidal thorn patch.” When we apply about 3 trials of these patches on the skin of a pain region, the pain region moves toward the spinal cord like a “cutaneous rabbit,” and finally, the pain vanishes. In the present review, we propose a molecular mechanism for this analgesic method or pain relief following application of the pyramidal thorn patch where firstly the mechanoreceptors and their related nerves under the skin are activated in response to touch. Transient receptor potential (TRP) channels serve as mechanosensitive channels within these mechanoreceptors. We further propose that activation of the nerves connected with the mechanoreceptors releases oxytocin, which has an antinociceptive function and activates TRP channels to hyperpolarize the pain signal nerves. We believe that our system will pave the way for alternative pain treatment.

Magnetic resonance arthrography of the shoulder: a painful procedure?

Objective

To compare the pain expected to that effectively caused by magnetic resonance arthrography of the shoulder and, secondarily, to describe a simplified approach to the technique for articular access.

Materials and Methods

We prospectively evaluated 40 participants who used a visual analog scale and a simplified categorical scale to indicate the level of pain expected and that experienced after the procedure, comparing the two with the Wilcoxon matched-pairs test. We also determined gender-related differences in pain conditions using the Mann-Whitney U test. In addition, we described a modified technique involving radiographic localization and the use of standard puncture needles for articular access.

Results

Analysis of the visual analog scales showed that the pain experienced was less than had been expected, with median scores of 1.75 and 3.75, respectively (p < 0.001). The level of pain expected was higher among women than among men, with median scores of 8.0 and 3.0, respectively (p = 0.014), as was the level of pain experienced, with median scores of 3.0 and 1.5, respectively (p = 0.139). The overall categorical evaluation corroborated that difference (p = 0.03). Articular access with the modified technique was successful in all patients.

Conclusion

Magnetic resonance arthrography of the shoulder is less painful than patients expect. In addition, digital radiographic guidance combined with the use of standard puncture needles appears to improve the efficiency of the method.

Does pain hypervigilance further impact the lack of habituation to pain in individuals with chronic pain? A cross-sectional pain ERP study

AIM

In chronic pain, habituation is believed to be impaired, and pain hypervigilance can enhance the pain experience. The goal of this study was to determine whether pain hypervigilance further worsens habituation of event-related potentials, measured in a pain-rating protocol of 25 painful somatosensory electrical stimuli, in patients with chronic pain.

METHODS

Pain hypervigilance was assessed with the Pain Vigilance Awareness Questionnaire and analyzed using the event-related fixed interval areas multilevel technique, which enables one to study within-session habituation. In a cohort of 111 participants, 33 reported chronic pain. This chronic pain group was compared with 33 pain-free individuals, matched for age and sex.

RESULTS

The relationship between pain status and habituation was not moderated by pain hypervigilance. Chronic pain status affected linear habituation and dishabituation (quadratic function) from 220 to 260 ms for nearly all electrodes, and from 580 to 640 ms for frontal electrodes. The effect of pain hypervigilance on habituation was observed primarily from 480 to 820 ms poststimulus for right-sided and central electrodes.

CONCLUSION

Pain hypervigilance and chronic pain independently influence habituation to painful stimuli - although not synergistically. To confirm that these effects are mediated by separate pathways, further research is required, in which electroencephalography is combined with other modalities with adequate spatial resolution, such as functional magnetic resonance imaging.

Perioperative pain management following total joint arthroplasty: A review and update to an institutional pain protocol

As the rate of total joint arthroplasty increases with the aging population of the United States, new focus on decreasing opioid use through the development of multimodal pain regimens (MPRs) is becoming an important area of research. MPRs use different agents and modes of delivery in order to synergistically address pain at many levels of the pain pathway. MPRs include a combination of acetaminophen, non-steroidal anti-inflammatory drugs (NSAIDs), gabapentinoids, opioids (short- and long-acting), spinal/epidural analgesia, regional nerve blocks, and local anesthetics. This review summarizes the available literature on major components of MPRs shown to be effective in the total joint arthroplasty population. Finally, the authors' preferred method for pain control in the TJA population is reviewed.

Thermal camera as a pain monitor

Objectives

Today, many subjective methods are used to measure pain. Wong Baker and Hicks Facial Pain Scale is one of the most commonly used method. Clinicians grade pain according to the facial mimetic reaction of the patient. Unfortunately, there is no objective measure for monitoring pain. By using the same principle of the Wong Baker and Hicks Facial Pain Scale, in this study, we aimed to objectively measure pain by using a thermal camera to detect instant facial temperature changes.

Materials and methods

Thirty volunteers who attended blood collection unit were subjected to facial thermal monitoring and measurements were obtained 5 minutes before needle puncture (BNP), during needle puncture (DNP), and after needle puncture (ANP). Data were processed with TestoIRSoft 3.8 software program and mean temperatures of the whole face (FFM) and highest temperature points (HP), horizontal line (HOR) between two pupils and first glabellar wrinkle, and bilateral lines starting from the nasolabial sulcus to oral commissure (NLS-1 at right, NLS-2 at left) were evaluated. All data were statistically analyzed with paired sample t-test.

Results

Statistically, temperature measurements of HOR, NLS-1, NLS-2, HP, and FFM were significantly higher between BNP and DNP, significantly lower between ANP and DNP, and significantly higher between BNP and ANP (p<0.05). The most interesting result in our analysis was that the HP point was between the two eyebrows in 26 of the 30 volunteers.

Conclusion

Our results suggest that a thermal camera can be used to objectively monitor pain and in follow-up. However, further studies involving non-healthy volunteers (especially high-fever patients, children, immunosuppressive patients, and cancer and intensive care patients) should be performed.

The Interface of Mechanics and Nociception in Joint Pathophysiology: Insights From the Facet and Temporomandibular Joints

Chronic joint pain is a widespread problem that frequently occurs with aging and trauma. Pain occurs most often in synovial joints, the body's load bearing joints. The mechanical and molecular mechanisms contributing to synovial joint pain are reviewed using two examples, the cervical spinal facet joints and the temporomandibular joint (TMJ). Although much work has focused on the macroscale mechanics of joints in health and disease, the combined influence of tissue mechanics, molecular processes, and nociception in joint pain has only recently become a focus. Trauma and repeated loading can induce structural and biochemical changes in joints, altering their microenvironment and modifying the biomechanics of their constitutive tissues, which themselves are innervated. Peripheral pain sensors can become activated in response to changes in the joint microenvironment and relay pain signals to the spinal cord and brain where pain is processed and perceived. In some cases, pain circuitry is permanently changed, which may be a potential mechanism for sustained joint pain. However, it is most likely that alterations in both the joint microenvironment and the central nervous system (CNS) contribute to chronic pain. As such, the challenge of treating joint pain and degeneration is temporally and spatially complicated. This review summarizes anatomy, physiology, and pathophysiology of these joints and the sensory pain relays. Pain pathways are postulated to be sensitized by many factors, including degeneration and biochemical priming, with effects on thresholds for mechanical injury and/or dysfunction. Initiators of joint pain are discussed in the context of clinical challenges including the diagnosis and treatment of pain.

Expectations towards participation in easily accessible pain management interventions: a qualitative study

BACKGROUND

People with chronic pain use a range of healthcare services, but they also report a high degree of dissatisfaction with treatments. One reason for dissatisfaction might be participants' expectations towards treatments. The aim of this study was to explore expectations of people with chronic pain towards participation in easily accessible pain management interventions delivered in public primary care.

METHODS

A qualitative study using semi-structured individual face-to-face interviews with 21 informants. The informants were recruited among participants enrolled in a randomised controlled trial on the effect of an easily accessible self-management course for people with chronic pain. The data were analysed thematically using Systematic Text Condensation.

RESULTS

Having experienced pain for a long time, there was no specific expectation of a cure or a significant alleviation of the pain. The informants' expectations mainly concerned a hope that participation could lead to a better everyday life. The informants said that hope was important as it motivated them to keep going and continue self-care activities. The hope acted as a driving force towards trying new interventions and maintaining motivation to do activities they experienced as beneficial. Both concrete aspects of the current intervention and an understanding of what interventions in general could offer contributed to the informants hope. The expectations centred about the interventions being something new, as they had not previously tried this service, an opportunity to gain and reinforce skills, to help them continue to grow as a person, to meet others in similar situations, and to access professional support in an easy manner. Participating in interventions provided by healthcare services was seen by some as an act of self-care, where they did something active to manage their health.

CONCLUSIONS

Expectations towards the interventions were related to a hope for participation leading to a better everyday life. The role of hope for peoples' motivation to self-care implies that service providers should be aware of and help to maintain hope for a better everyday life. The importance of social support as part of self-care should be acknowledged when developing interventions targeting chronic pain.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02531282 . Registered on August 21 2015.

A randomized controlled trial on the long-term effects of proprioceptive neuromuscular facilitation training, on pain-related outcomes and back muscle activity, in patients with chronic low back pain

BACKGROUND

The role of exercise therapy in improving pain-related clinical outcomes and trunk muscle activity in patients with chronic low back pain (CLBP) has been widely reported. There is little information on the effect of proprioceptive neuromuscular facilitation (PNF) training in patients with CLBP. The purpose of the present study was therefore to investigate the persistence of the effects of PNF training on pain intensity, functional disability, patient satisfaction, health-related quality of life (HRQOL) and lower back muscle activity in patients with CLBP.

METHODS

Forty-two participants with CLBP were randomly assigned either to 4-week PNF training or to a control group receiving a Low back pain educational booklet. Pain-related outcomes, including pain intensity, functional disability, patient satisfaction, HRQOL and lumbar erector spinae (LES) muscle activity, were measured before and after the intervention, and at a follow-up session 12 weeks after the last intervention session.

RESULTS

Compared with the control group, after undergoing a 4-week PNF training intervention, participants showed a significant reduction in pain intensity and functional disability, and improved patient satisfaction and HRQOL (p < 0.01). These effects were still significant at the 12-week follow-up assessment (p < 0.01). LES muscle activity in the PNF training group was significantly increased throughout the measurement periods compared with controls (p < 0.01).

CONCLUSIONS

The study found that 4-week PNF training has positive long-term effects on pain-related outcomes, and increases lower back muscle activity in patients with CLBP.