Variability in negative emotions among individuals with chronic low back pain: relationships with pain and function

Association between perception of harm and valence of shoulder movement images with disability levels related to chronic shoulder pain

ABSTRACT

Recent studies highlight an interplay between pain perception and emotional responses. This necessitates a thorough investigation into how beliefs and motivational influences respond to visual stimuli of movements. Such an analysis is crucial for understanding the extent to which these factors contribute to disability levels associated with shoulder pain. We aimed to investigate the relationship between the perception of harm and the valence in images depicting shoulder movements and determine how these perceptions are linked to disability levels associated with shoulder pain. This cross-sectional study recruited 42 individuals with chronic shoulder pain. Participants were presented with 58 shoulder movements images. Each participant evaluated these images for emotional valence and arousal using the self-assessment manikin. For every image, they provided their level of avoidance, fear, and perception of harm in a numerical scale. We measured disability levels and pain catastrophizing using the Shoulder Pain and Disability Index and the Pain Catastrophizing Scale. A direct acyclic graph was used. Multiple linear regression analysis was conducted with shoulder disability as the dependent variable and perception of harm and valence as independent variables, adjusted for the confounders catastrophizing and arousal. This analysis resulted in a significant model (F4,37 = 11.44; adjusted R2 = 0.547; P < 0.01). The perception of harm to shoulder movement (β = 0.11; P < 0.001; 95% confidence interval = 5.6-11.8) was significantly associated with the level of shoulder disability, whereas valence did not show a significant association (β = 0.26; P = 0.15; 95% confidence interval = 1.7-10.8). The perception of harm associated with shoulder movements images during daily activities was associated with disability. Individuals who believe that shoulder movements are harmful have greater disability.

Concurrent and lagged associations among pain medication use, pain, and negative affect: a daily diary study of people with chronic low back pain

ABSTRACT

People with chronic pain often attempt to manage pain and concurrent emotional distress with analgesic substances. Habitual use of such substances-even when not opioid-based-can pose side effect risks. A negative reinforcement model has been proposed whereby relief of pain and emotional distress following medication consumption increases the likelihood that the experience of elevated pain and distress will spur further medication use. People with chronic low back pain (N = 105) completed electronic diary assessments 5 times/day for 14 consecutive days. Lagged and cross-lagged analyses focused on links between time 1 pain and negative affect (NA) and time 2 analgesic medication use and vice versa. Sex differences were also explored. Primary results were as follows: (1) participants on average reported taking analgesic medication during 41.3% of the 3-hour reporting epochs (29 times over 14 days); (2) time 1 within-person increases in pain and NA predicted time 2 increases in the likelihood of ingesting analgesic medications; (3) time 1 within-person increases in medication use predicted time 2 decreases in pain and NA; and (4) lagged associations between time 1 pain/NA and time 2 medication use were strongest among women. Findings suggest that the use of analgesic medications for many people with chronic pain occurs frequently throughout the day. Results support the validity of a negative reinforcement model where pain and distress lead to pain medication use, which in turn leads to relief from pain and distress.

Underestimating or Overestimating Improvement in Pain on a Smartphone Pain App: Role of Disability, Negative Affect, and Pain App Engagement

Clinicians often ask people with chronic pain about their perceived benefit from interventions designed to improve their pain. The aim of this study is to identify factors that contribute to underestimating or overestimating perceived changes in daily pain intensity over a month of daily assessments. We examined data from individuals with chronic pain who provided at least 28 daily assessments using a pain app as secondary analyses. Participants provided baseline demographic information and completed questionnaires assessing pain, activity interference, mood, pain disability, and catastrophizing. Using the pain app, they entered daily ratings of pain (0 = none, 10 = worst pain possible) and impressions of perceived day-to-day change (0 = better, 5 = same, and 10 = worse). Two hundred fifty-two (N = 252) subjects with chronic pain met the inclusion criteria of completing at least 28 daily assessments. Those who underestimated their improvement tended to have higher pain intensity at baseline (P < .001), reported greater activity interference and disability (P < .001), and were prone to greater catastrophizing and anxiety and depression (P < .01). People who were more accurate in assessing their improvement engaged less with the app with fewer 2-way messages compared with those who either underestimated or overestimated their improvement and who had more 2-way messaging (P < .05). This longitudinal study suggests that those who report greater levels of catastrophizing and anxiety and depression are more likely to underestimate any improvements in their pain over time but seem to engage more with a pain app. Future research will help in our understanding of what magnitude of perceived change in pain ratings is clinically meaningful. PERSPECTIVE: Those who report greater levels of pain, disability, anxiety, depression, and catastrophizing are most prone to underestimate improvements of their pain over time.

Parent Anxiety, Depression, Protective Responses, and Parenting Stress in the Context of Parent and Child Chronic Pain: A Daily Diary Study of Parent Variability

Parents with (vs without) chronic pain report poorer psychosocial functioning (eg, worse mental health, parenting difficulties), which has been linked to poorer child outcomes (eg, child pain). However, emerging research suggests that individuals vary in their functioning from day-to-day, particularly those with chronic pain. This study used daily diaries to compare parents with (versus without) chronic pain on variability in their anxiety, mood, protective responses, and parenting stress. We also examined parent chronic pain status as a moderator of the associations between parent variability and youth daily pain and interference. Participants were 76 youth with chronic pain (Mage = 14.26; 71.1% female) and one of their parents (89.5% mothers; n = 38 or 50.0% endorsing chronic pain). Parents and youth completed self-report questionnaires and 7 days of diaries. Parent variability was calculated to reflect the frequency and size of day-to-day changes. Multilevel models revealed that parents with (vs without) chronic pain were significantly more variable in their parenting stress, but not in their anxiety, mood, or protective responses. Contrary to hypotheses, parent variability was not significantly related to youth daily pain intensity or interference and parent chronic pain did not moderate any associations. Instead, mean levels of parent anxiety, protective responses, and parenting stress across the week significantly predicted youth daily pain interference. Findings suggest that while variability was observed among parents (with and without chronic pain) of youth with chronic pain, it did not significantly predict youth's daily pain-related functioning. Further research is needed to confirm these initial findings. PERSPECTIVE: Parents with chronic pain have expressed concerns that the variable nature of their pain negatively impacts their children. Our results found that parents (with and without chronic pain) were variable in their anxiety, mood, protective responses, and parenting stress, but this variability did not significantly predict youth's chronic pain-related functioning.

Cognitive behavioral therapy achieves better benefits in relieving postoperative pain and improving joint function: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Cognitive behavioral therapy (CBT) is a structured, short-term psychotherapy approach that may have positive effects in terms of relieving postoperative pain. The main objective of this study was to determine the effect of CBT on pain and joint function in patients after total joint arthroplasty.

METHODS

We searched 3 electronic databases including randomized controlled studies (RCTs) using CBT as an intervention. The main results of this study were to determine pain intensity by NRS, VAS, WOMAC pain Scale, PCS, and joint function by HHS, OKS, EQ-5D, ROM. Data extraction and quality assessment of included RCTs were independently performed by the authors and date analysis was performed by RevMan V.5.4.

RESULTS

Among the 605 studies, 9 RCTS were included in this systematic review and meta-analysis. The study showed that the difference between CBT and usual care groups in PCS (≤3months), NRS, VAS (≤3months) were statistically significant (P < 0.05); the difference between CBT and usual care groups in PCS (≥12months), WOMAC Pain Scale, and VAS (≥12months) were not statistically significant (P > 0.05), indicating that CBT can improve pain in patients after arthroplasty in the early term. In addition, the difference between CBT and usual care groups in OKS (≤3months), HSS, ROM (≤3months), EQ-5D (≤3months) were not statistically significant (P > 0.05); the difference between CBT and usual care groups in EQ-5D (≥12months) were statistically significant (P < 0.05), indicating that the quality of life in patients after total joint arthroplasty were improved with the extension of follow-up time.

CONCLUSIONS

This study shows that CBT can relieve pain in patients with total joint arthroplasty in the early postoperative period and improve quality of life to some extent over time.

Soreness Reminds Me of Grief: Patients With Chronic Pain Show Less Differentiated Representations of Emotional Feelings and Bodily States

People experience similarities between emotional feelings and bodily states on a daily basis, but both the magnitude and pervasiveness of this experiential similarity vary across individuals. Inspired by previous findings that chronic pain (CP) is characterized by strengthened pain-affect coupling and reduced interoceptive accuracy, we conducted 2 cross-sectional studies to examine whether patients with CP would exhibit less differentiated perception and mental representation of emotional feelings and bodily states. In study 1 (N = 500), patients with CP and healthy controls (HCs) completed a self-report questionnaire that asked explicitly about the perceived similarity between 5 basic emotion categories and a series of bodily states. In study 2 (N = 73), a specially designed false memory test was administered to examine whether patients with CP would have reduced differentiation of concepts of negative emotion and somatic distress. We found that patients with CP perceived greater and more pervasive similarities between emotional feelings and bodily states, as indicated by higher questionnaire scores and denser, less specialized bipartite emotion-body networks, both associated with lower subjective interoceptive accuracy. Furthermore, patients with CP formed false memories of negative emotion words (eg, grief) more readily than HCs after memorizing somatic distress words (eg, soreness), as if they represented negative emotion and somatic distress as a single, enmeshed semantic category. Our findings extend previous literature by demonstrating reduced discrimination between emotional and bodily experiences in CP that is not restricted to pain-related emotional and sensory experiences and may be related to a fundamentally less differentiated interoception. PERSPECTIVES: This study shows that patients with chronic pain have a profoundly less differentiated perception and implicit conceptualization of emotional feelings and bodily states, which appears to be associated with altered interoception. These findings may provide new perspectives on why they often experience a stronger pain-affect coupling.

Top Ten Tips Palliative Care Clinicians Should Know About Behavioral Pain Management for Persistent Pain

Seriously ill patients often experience persistent pain. As a part of a comprehensive repertoire of pain interventions, palliative care clinicians can help by using behavioral pain management. Behavioral pain management refers to evidence-based psychosocial interventions to reduce pain intensity and enhance functional outcomes and quality of life. Conceptualized using the biopsychosocial model, techniques involve promoting helpful behaviors (e.g., activity pacing, stretching, and relaxation exercises) and modifying underlying patterns of thinking, feeling, and communicating that can exacerbate pain. The authors have expertise in pain management, clinical health psychology, geropsychology, behavioral science, and palliative medicine. The article reviews the current evidence for behavioral interventions for persistent pain and provides 10 recommendations for behavioral pain management.

Emotional Imagery Influences the Adaptive Force in Young Women: Unpleasant Imagery Reduces Instantaneously the Muscular Holding Capacity

The link between emotions and motor function has been known for decades but is still not clarified. The Adaptive Force (AF) describes the neuromuscular capability to adapt to increasing forces and was suggested to be especially vulnerable to interfering inputs. This study investigated the influence of pleasant and unpleasant food imagery on the manually assessed AF of elbow and hip flexors objectified by a handheld device in 12 healthy women. The maximal isometric AF was significantly reduced during unpleasant vs. pleasant imagery and baseline (p < 0.001, dz = 0.98−1.61). During unpleasant imagery, muscle lengthening started at 59.00 ± 22.50% of maximal AF, in contrast to baseline and pleasant imagery, during which the isometric position could be maintained mostly during the entire force increase up to ~97.90 ± 5.00% of maximal AF. Healthy participants showed an immediately impaired holding function triggered by unpleasant imagery, presumably related to negative emotions. Hence, AF seems to be suitable to test instantaneously the effect of emotions on motor function. Since musculoskeletal complaints can result from muscular instability, the findings provide insights into the understanding of the causal chain of linked musculoskeletal pain and mental stress. A case example (current stress vs. positive imagery) suggests that the approach presented in this study might have future implications for psychomotor diagnostics and therapeutics.

Strengths and limitations of diagnostic tools for endometriosis and relevance in diagnostic test accuracy research

Endometriosis is a chronic systemic disease that can cause pain, infertility and reduced quality of life. Diagnosing endometriosis remains challenging, which yields diagnostic delays for patients. Research on diagnostic test accuracy in endometriosis can be difficult due to verification bias, as not all patients with endometriosis undergo definitive diagnostic testing. The purpose of this State-of-the-Art Review is to provide a comprehensive update on the strengths and limitations of the diagnostic modalities used in endometriosis and discuss the relevance of diagnostic test accuracy research pertaining to each. We performed a comprehensive literature review of the following methods: clinical assessment including history and physical examination, biomarkers, diagnostic imaging, surgical diagnosis and histopathology. Our review suggests that, although non-invasive diagnostic methods, such as clinical assessment, ultrasound and magnetic resonance imaging, do not yet qualify formally as replacement tests for surgery in diagnosing all subtypes of endometriosis, they are likely to be appropriate for advanced stages of endometriosis. We also demonstrate in our review that all methods have strengths and limitations, leading to our conclusion that there should not be a single gold-standard diagnostic method for endometriosis, but rather, multiple accepted diagnostic methods appropriate for different circumstances. © 2022 International Society of Ultrasound in Obstetrics and Gynecology.

Association of parental and adolescent emotion-related factors with adolescent chronic pain behaviors

ABSTRACT

Chronic pain is a prevalent condition in youth, and the pain experience is strongly influenced by emotional processes. Studying emotion variability and regulation (ER) may help better understand pain behavior. As the development of emotion-related abilities predominantly takes place in the family context, examining ER within parent-adolescent dyads is important. We set out to test the association of parent and adolescent ER and adolescent emotional variability with adolescent pain behavior (ie, pain interference, activity avoidance, and activity engagement). A sample of 56 adolescents (Mage = 14.5, 85.7% women) with chronic pain and one of their parents (92.9% mothers) participated in this study. Adolescents completed baseline measures of average pain intensity, ER, and mean positive and negative affect. Furthermore, adolescents completed an electronic diary for 14 consecutive days, reporting on emotional state, activity avoidance, activity engagement, and pain interference. Parents completed measures of ER and their own history of pain. We performed a variable selection procedure, the least absolute shrinkage and selection operator method, to determine important predictors of adolescent pain behavior. Adolescent high positive affect was associated with more activity engagement, less pain interference, and less activity avoidance, indicating that positive affect might enhance the willingness to engage in activities in the presence of pain. Adolescent ER strategy emotional reappraisal and parents' own history of pain were predictors of less activity engagement. Parent ER was not related to adolescent ER. In conclusion, our results highlight the potential of enhancing positive affect as an intervention target for chronic pain.

Self-Reported Pain and Emotional Reactivity in Bipolar Disorder: A Prospective FACE-BD Study

In patients with bipolar disorder (BD), pain prevalence is close to 30%. It is important to determine whether pain influences BD course and to identify factors associated with pain in BD in order to guide BD management. This naturalistic, prospective study used data on 880 patients with BD from the French FACE-BD cohort who were divided into two groups according to the presence or absence of pain. Multivariate models were used to test whether pain was associated with affective states and personality traits while controlling for confounders. Then, multivariate models were used to test whether pain at baseline predicted global life functioning and depressive symptomatology at one year. At baseline, 22% of patients self-reported pain. The pain was associated with depressive symptomatology, levels of emotional reactivity in a quadratic relationship, and a composite variable of personality traits (affective lability, affective intensity, hostility/anger, and impulsivity). At one year, the pain was predictive of depression and lower global life functioning. Pain worsens mental health and well-being in patients with BD. The role of emotions, depression, and personality traits in pain has to be elucidated to better understand the high prevalence of pain in BD and to promote specific therapeutic strategies for patients experiencing pain.

An Ecological Momentary Assessment Study of Pain Intensity Variability: Ascertaining Extent, Predictors, and Associations With Quality of Life, Interference and Health Care Utilization Among Individuals Living With Chronic Low Back Pain

This ecological momentary assessment (EMA) study examined the extent of pain intensity variability among 140 individuals with chronic low back pain and explored predictors of such variability and psychosocial and health care utilization outcomes. Individuals completed momentary pain intensity reports (0-10 numeric rating scale) several times daily for two periods of seven consecutive days, one month apart. Participants also completed online questionnaires at baseline which tapped into pain characteristics, pain-related catastrophization, kinesiophobia, activity patterns, and depression and anxiety symptoms. Questionnaires assessing quality of life and health care utilization were administered online one month after completion of the last EMA report. Data were analyzed using linear hierarchical location-scale models. Results showed that pain intensity fluctuated over the course of a week as shown by an average standard deviation of 1.2. The extent of variability in pain intensity scores was heterogeneous across participants but stable over assessment periods. Patients' baseline characteristics along with psychosocial and health care utilization outcomes were not significantly associated with pain intensity variability. We conclude that pain intensity variability differs across patients yet correlates remain elusive. There is an important gap in our knowledge of what affects this variability. Future EMA studies should replicate and extend current findings. PERSPECTIVE: This study provides evidence indicating that there is substantial variability in momentary reports of pain intensity among individuals living with chronic low back pain. However, risk and protective factors for greater lability of pain are elusive as is evidence that greater pain intensity variability results in differential health care utilization.

Cognitive behavioral therapy cannot relieve postoperative pain and improve joint function after total knee arthroplasty in patients aged 70 years and older

PURPOSE

A randomized controlled trial was conducted to investigate whether cognitive behavioral therapy (CBT) can improve postoperative pain, knee function, and negative emotion in patients aged 70 years and older who underwent total knee arthroplasty (TKA).

METHODS

This study used randomized, parallel group, controlled trial to divide the included 90 patients into CBT group and usual care group. The primary outcome measure of the study was the Visual Analogue Scale (VAS) at activity. The secondary outcome measures included the Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS), Knee Range of Motion (ROM), Oxford Knee Score (OKS), Hospital for Special Surgery Knee Rating Scale (HSS), analgesics dose, and postoperative complications.

RESULTS

83 patients who met the criteria were randomized into CBT group and usual care group. In the SAS, score of the CBT group decreased by 4.3 points at 7th day and 8.2 at 14th day after surgery with respect to preoperative SAS score, the usual care group increased by 1.5 at 7th day and decreased 1.1 at 14th day, and tended to be similar at 3rd month after surgery. There were no significant differences at 7th and 14th day in SDS, however, score of the CBT group was 5.8 and the usual care group was 1.9 at 3rd month after surgery. No statistically significant differences in VAS at activity, ROM, OKS, HSS, analgesics frequency, and postoperative complications between two groups.

CONCLUSIONS

CBT was superior to usual care group in relieving anxiety at 7th day and 14th day, and depression at 3rd month, however, CBT cannot relieve postoperative pain and improve joint function after TKA in patients aged 70 years and older.

A Dyadic Investigation of Depressed Affect and Interspousal Behavior in Couples With Chronic Back Pain

BACKGROUND

Depression and marital discord are characteristic not only of individuals with chronic low back pain (ICPs) but also of their spouses.

PURPOSE

We examined actor-partner interdependence models to evaluate associations among depressed affect and criticism and support of partners at the same time point (concurrent effects) and 3 hr later (lagged effects). Fully dyadic models were used to account for both within-person and cross-spouse associations among depressed affect, criticism, and support for ICPs and spouses. We also examined the direction of the relationships (depressed affect predicting behavior and behavior predicting depressed affect) all while controlling for pain intensity, pain behavior, and the prior dependent variable.

METHODS

ICPs (n = 105) and their spouses completed electronic diary measures of depressed affect and behavior (criticism and support) five times a day for 2 weeks. Hierarchical linear modeling with person-mean centering was used for data analysis.

RESULTS

Within the same 3 hr epoch, more depressed affect was related to higher criticism and generally less support. Lagged analyses suggested bidirectional relationships between spouse's own depressed affect and spouse's own criticism of ICPs. Spouse depressed affect was also associated with decreased support received from ICPs. Pain behavior and pain intensity were also related to depressed affect, criticism, and support especially concurrently.

CONCLUSIONS

Theories and interventions need to address not only ICP depressed affect but also spouse depressed affect, as spouse depressed affect may be a stress generating precursor to criticism and support.

Variability in Hourly Activity Levels: Statistical Noise or Insight Into Older Adult Frailty?

BACKGROUND

Frailty is associated with lower mean activity; however, hourly activity is highly variable among older individuals. We aimed to relate frailty to hourly activity variance beyond frailty's association with mean activity.

METHOD

Using the 2010-2011 National Social Life, Health and Aging Project wrist accelerometry data (n = 647), we employed a mixed-effects location scale model to simultaneously determine whether an adapted phenotypic frailty scale (0-4) was associated with the log10-mean hourly counts per minute (cpm) and between-and within-subject hourly activity variability, adjusting for demographics, health characteristics, season, day-of-week, and time-of-day. We tested the significance of a Frailty × Time-of-day interaction and whether adjusting for sleep time altered relationships.

RESULTS

Each additional frailty point was associated with a 7.6% (10-0.0343, β = -0.0343; 95% CI: -0.05, -0.02) lower mean hourly cpm in the morning, mid-day, and late afternoon but not evening. Each frailty point was also associated with a 24.5% (e0.219, β = 0.219; 95% CI: 0.09, 0.34) greater between-subject hourly activity variance across the day; a 7% (e0.07, β = 0.07; 95% CI: 0.01¸ 0.13), 6% (e0.06, β = 0.06; 95% CI: 0, 0.12), and 10% (e0.091, β = 0.091; 95% CI: 0.03, 0.15) greater within-subject hourly activity variance in the morning, mid-day, and late afternoon, respectively; and a 6% (e-0.06, β = -0.06; 95% CI: -0.12, -0.003) lower within-subject hourly activity variance in the evening. Adjusting for sleep time did not alter results.

CONCLUSIONS

Frail adults have more variable hourly activity levels than robust adults, a potential novel marker of vulnerability. These findings suggest a need for more precise activity assessment in older adults.

Adaptive Force and emotionally related imaginations - preliminary results suggest a reduction of the maximal holding capacity as reaction to disgusting food imagination

The link between emotions and motor control has been discussed for years. The measurement of the Adaptive Force (AF) provides the possibility to get insights into the adaptive control of the neuromuscular system in reaction to external forces. It was hypothesized that the holding isometric AF is especially vulnerable to disturbing inputs. Here, the behavior of the AF under the influence of positive (tasty) vs. negative (disgusting) food imaginations was investigated. The AF was examined in n = 12 cases using an objectified manual muscle test of the hip flexors, elbow flexors or pectoralis major muscle, performed by one of two experienced testers while the participants imagined their most tasty or most disgusting food. The reaction force and the limb position were measured by a handheld device. While the slope of force rises and the maximal AF did not differ significantly between tasty and disgusting imaginations (p > 0.05), the maximal isometric AF was significantly lower and the AF at the onset of oscillations was significantly higher under disgusting vs. tasty imaginations (both p = 0.001). A proper length tension control of muscles seems to be a crucial functional parameter of the neuromuscular system which can be impaired instantaneously by emotionally related negative imaginations. This might be a potential approach to evaluate somatic reactions to emotions.

The role of affect in chronic pain: A systematic review of within-person symptom dynamics

OBJECTIVE

Chronic pain is conceptualized as a biopsychosocial phenomenon that involves both physical and emotional processes. The vast majority of research regarding these facets of chronic pain characterizes differences between individuals. In this review, we describe problems with assuming that differences between persons accurately characterize within-person processes. We also provide a systematic review of studies that have examined within-person relationships between pain and affect among individuals with chronic pain.

METHOD

Articles published by December 2020 that pertained to within-person assessment of pain and emotion, affect, or mood were identified. Data regarding study design, adherence, and concurrent and prospective relationships among pain and affect variables were extracted and summarized.

RESULTS

Of 611 abstracts, 55 studies met inclusion criteria. Results suggest that individuals with chronic pain tend to experience increased negative affect and decreased positive affect when experiencing more severe pain (r_pooled = .18 and - .19, respectively). However, the size of these effects appeared smaller than between-person associations, and there was evidence of significant variability between individuals. Examination of predictive relationships between pain and affect largely suggested the tendency of symptoms to predict themselves, rather than pain predicting affect or vice versa.

CONCLUSIONS

Consistent with group-level relationships, experiencing more severe pain relative to an individual's average seems to be associated with more negative affect and less positive affect. However, individuals vary in the size and even direction of these effects. More research is necessary to understand the implications of such variability for the assessment and treatment of chronic pain.

Morning Bright Light Treatment for Chronic Low Back Pain: Potential Impact on the Volatility of Pain, Mood, Function, and Sleep

OBJECTIVES

Most treatment outcome studies for people with chronic low back pain (CLBP) have based analyses on and reported only the mean levels of these factors. However, high levels of pain, mood, function, and sleep volatility may represent unique factors contributing to diminished quality of life. Our goal was to determine whether bright light treatment affected both mean levels of pain, mood, function, and sleep and reduced volatility in these outcomes.

METHODS

US military veterans with CLBP (N = 22) underwent an open trial with a seven-day baseline, followed by 13 days of a one-hour morning bright light treatment self-administered at their home and a 30-day follow-up. Participants completed daily diary measures at 12 Pm and 6 Pm every day during the three study epochs.

RESULTS

Using location scale modeling, results suggested that, in addition to being associated with changes in mean levels of pain intensity, pain interference, negative affect, and sleep quality, bright light treatment was also related to reductions in the volatility of pain intensity and negative affect, reductions that were largely maintained during follow-up.

CONCLUSIONS

Changes in mean levels and volatility were independent factors, suggesting that bright light treatment was related to participants experiencing fewer "pain flares." These findings underscore the potential importance of volatility as a future treatment target.

Study on the Associations of Individual and Work-Related Factors with Low Back Pain among Manufacturing Workers Based on Logistic Regression and Structural Equation Model

Work-related musculoskeletal injuries are one of the major occupational health issues of the workers, especially low back pain (LBP). The aim of this study was to survey the prevalence of LBP among manufacturing workers and to identify associations of individual and work-related factors with LBP. A cross-sectional questionnaire study was performed with 1173 participating manufacturing workers. The questionnaire included individual factors, psychosocial and physical exposures, and musculoskeletal discomfort. It was analyzed by logistic regression and structural equation modeling (SEM). The 1-year prevalence of LBP among Chinese manufacturing workers was 33.6%. Logistic regression analysis showed that job tenure, awkward postures, vibration and job demand were positively—while social support and job control were negatively associated with LBP (p < 0.05). The SEM results indicated that, as shown in other studies, job types, job tenure, postural load, high job demand, low job control and vibration were directly associated with LBP, but also that job types, high job demand, low social support and vibration may have indirect effects on LBP—mediated by postural load.

Accelerated brain aging in chronic low back pain

Chronic low back pain (CLBP) is a leading cause of disability and is associated with neurodegenerative changes in brain structure. These changes lead to impairments in cognitive function and are consistent with those seen in aging, suggesting an accelerated aging pattern. In this study we assessed this using machine-learning estimated brain age (BA) as a holistic metric of morphometric changes associated with aging. Structural imaging data from 31 non-depressed CLBP patients and 32 healthy controls from the Pain and Interoception Imaging Network were included. Using our previously developed algorithm, we estimated BA per individual based on grey matter density. We then conducted multivariable linear modeling for effects of group, chronological age, and their interaction on BA. We also performed two voxel-wise analyses comparing grey matter density between CLBP and control individuals and the association between gray matter density and BA. There was an interaction between CLBP and greater chronological age on BA such that the discrepancy in BA between healthy and CLBP individuals was greater for older individuals. In CLBP individuals, BA was not associated with sex, current level of pain, duration of CLBP, or mild to moderate depressive symptoms. CLBP individuals had lower cerebellar grey matter density compared to healthy individuals. Brain age was associated with lower gray matter density in numerous brain regions. CLBP was associated with greater BA, which was more profound in later life. BA as a holistic metric was sensitive to differences in gray matter density in numerous regions which eluded direct comparison between groups.

Machine learning suggests sleep as a core factor in chronic pain

Patients with chronic pain have complex pain profiles and associated problems. Subgroup analysis can help identify key problems. We used a data-based approach to define pain phenotypes and their most relevant associated problems in 320 patients undergoing tertiary pain management. Unsupervised machine learning analysis of parameters "pain intensity," "number of pain areas," "pain duration," "activity pain interference," and "affective pain interference," implemented as emergent self-organizing maps, identified 3 patient phenotype clusters. Supervised analyses, implemented as different types of decision rules, identified "affective pain interference" and the "number of pain areas" as most relevant for cluster assignment. These appeared 698 and 637 times, respectively, in 1000 cross-validation runs among the most relevant characteristics in an item categorization approach in a computed ABC analysis. Cluster assignment was achieved with a median balanced accuracy of 79.9%, a sensitivity of 74.1%, and a specificity of 87.7%. In addition, among 59 demographic, pain etiology, comorbidity, lifestyle, psychological, and treatment-related variables, sleep problems appeared 638 and 439 times among the most important characteristics in 1000 cross-validation runs where patients were assigned to the 2 extreme pain phenotype clusters. Also important were the parameters "fear of pain," "self-rated poor health," and "systolic blood pressure." Decision trees trained with this information assigned patients to the extreme pain phenotype with an accuracy of 67%. Machine learning suggested sleep problems as key factors in the most difficult pain presentations, therefore deserving priority in the treatment of chronic pain.

The synergistic effect between interoceptive accuracy and alcohol use disorder status on pain sensitivity

BACKGROUND

Interoceptive accuracy and pain sensitivity are both risk factors in the development of alcohol use disorder (AUD). However, the synergistic association between these two factors has not been investigated in an AUD sample. Therefore, the aim of the current study was to investigate whether the association between interoceptive accuracy and sensitivity to pain differed across AUD status.

METHODS

The study group included 165 individuals diagnosed with AUD (88.1% men) and 110 healthy controls (HCs; 74.5% men). Interoceptive accuracy was assessed with the Schandry Task. The Pain Sensitivity Questionnaire was utilized to measure sensitivity to pain. Anxiety, biological sex, and age were included as covariates in a model examining the role of AUD status as a moderator in the association between interoceptive accuracy and pain sensitivity.

RESULTS

A significant interaction was found between interoceptive accuracy and AUD status (b = -4.580, 95% CI = [-8.137, -1.022], p = 0.012, ΔR² = 0.032). Findings indicate that interoceptive accuracy was negatively associated with pain sensitivity among individuals with AUD, while there was a trend for an opposite association among healthy controls.

CONCLUSION

We hypothesize that persistent alcohol drinking may contribute to disruption of the normative association between interoception and pain. Future studies should be conducted to develop knowledge on this association and to investigate its possible therapeutic significance and implications.

Altered regulation of negative affect in patients with fibromyalgia: A diary study

BACKGROUND

Fibromyalgia is characterized by widespread musculoskeletal pain and often accompanied by cognitive and emotional problems. Adaptation to fibromyalgia may therefore also rely on one's ability to regulate emotional problems. In this study, we examined two indices of emotion regulation, that is, (a) affective instability, involving frequent large fluctuations in self-reported affect, and (b) resting heart rate variability (HRV).

METHODS

Participants were 46 patients with fibromyalgia (M_age  = 45.4 years; 39 females) and 46 matched healthy controls (M_age  = 44.9 years; 37 females). Heart rate was monitored under resting conditions to derive HRV. Subsequently, participants completed an electronic end-of-day diary for 14 consecutive days assessing daily levels of pain, disability, negative affect (NA) and positive affect (PA). Affective instability was operationalized as the mean square of successive differences in daily mood.

RESULTS

Results indicate increased levels of NA instability and reduced levels of HRV in patients with fibromyalgia in comparison with healthy controls. Furthermore, HRV and NA instability were inversely related. Finally, in patients, higher NA instability was related to increased pain disability.

CONCLUSIONS

Current findings support the idea that patients with fibromyalgia are confronted with fluctuating emotions. These results may have important implications for treatment as they provide support for the use of emotion regulation skills training in patients with fibromyalgia to impact upon NA instability.

SIGNIFICANCE

This study provides novel insight in the link between emotion regulation indices,that is, heart-rate variability and negative affective (NA) instability, in patients with fibromyalgia, and presents evidence for differences in both emotion regulation indices between patients with fibromyalgia and healthy people. Furthermore, results link increased NA instability with increased levels of daily disability in patients with fibromyalgia. Together, these findings offer support for a key role of emotion regulation in fibromyalgia outcomes, providing pathways for clinical practice.

Relationship Between Spiritual Health and Pain Self-Efficacy in patients with Chronic Pain: A Cross-Sectional Study in West of Iran

In recent years, the prevalence of chronic diseases has had a growing trend, which has resulted in many health problems. Level of belief in God is effective on people's attitudes to life concepts, social deviations and psychological disorders, and improves them. Therefore, the present research was conducted with the aim of determining the relationship between spiritual health (SH) and pain self-efficacy (PSE) in Ilam City in 2018. This study was a descriptive cross-sectional study in the group of patients with chronic pain (CP). In this study, the study population was patients with CP in Ilam City and the study sample was 150 patients with CP referring to public and private health centers in Ilam, which had all the criteria for participation in the study. The findings showed mean (SD) of the total score of SH variables was 65.16 (9.88), and PSE was 34.48 (4.08). According to Pearson statistical analysis, there is a significant relationship between SH and PSE (r = 0.442, P = 0.000). Also, the standard beta and non-standard beta coefficients for SH variables in PSE show that the non-standard beta coefficient in SH is equal to 0.183. The results of this study showed that SH is a predictor of pain acceptance, so that patients who were more religious were more likely to tolerate CP. For this reason, it is suggested that religious interventions be performed to reduce pain in patients with CP, in order to provide the necessary context for pain reduction in this group of patients.

A Prospective Study of Dorsal Root Ganglion Stimulation for Non-Operated Discogenic Low Back Pain

INTRODUCTION

Disruptions of lumbar intervertebral discs may lead to severe discogenic low back pain (LBP). Severe pain has a deleterious effect on physical function and quality of life. Spinal cord stimulation (SCS) is a robust treatment for many neuropathic pain conditions. New innovations may be well-suited to treat neuropathic chronic LBP, including discogenic pain. The aim of this prospective study was to determine the effect of dorsal root ganglion (DRG) stimulation for a well-selected group of patients with discogenic LBP with no history of previous back surgeries.

METHODS

Twenty subjects with confirmed discogenic LBP and no prior history of back surgery underwent trials of DRG stimulation and, if successful with at least 50% pain reduction, were permanently implanted. Subjects rated their pain, disability, quality of life, and mood at baseline, and 14 subjects were followed through 12 months of treatment.

RESULTS

Treatment with DRG stimulation reduced LBP ratings (68.3% reduction), from mean 7.20 ± 1.3 at baseline to 2.29 ± 2.1 after 12 months (p = < 0.001). Oswestry ratings of disability significantly decreased (p = < 0.001) from 42.09 ± 12.9 at baseline to 21.54 ± 16.4 after six months of treatment and to 20.1 ± 16.6 after 12 months. The average quality of life EQ-5D index score at baseline was 0.61 ± 0.12 and 0.84 ± 0.13 after 12 months.

DISCUSSION

DRG stimulation treatment for discogenic LBP improved the level of pain, function, and quality of life. Further research is necessary into efficacy of DRG stimulation in patients with chronic discogenic LBP and to determine the place of SCS in the treatment algorithm.

Action of ear acupuncture in people with chronic pain in the spinal column: a randomized clinical trial1

OBJECTIVES

to assess the action of ear acupuncture on disability and tissue temperature in people with chronic pain in the spinal column.

METHOD

a clinical trial with a sample of 110 people, randomized into three groups: Treatment, Placebo and Control. The assessment instruments were the Rolland Morris Disability Questionnaire (RMDQ) and a thermographic camera, administered before the first treatment session, one week after and 15 days after (follow-up) the fifth session of ear acupuncture. In the analysis of the data, the Kruskal Wallis, Student-Newman Keuls and Wilcoxon tests were applied.

RESULTS

there was a significant reduction in disability in the Treatment and Placebo groups between the initial and final assessments (p<0.05) and between the initial assessments and follow-up (p<0.05). In the final assessment, the Treatment group presented improvement of disability when compared with the Placebo and Control groups (p<0.05). There was an increase in mean tissue temperature of the dorsal region between the initial and follow-up assessments in Treatment and Control groups (p<0.05), and between the final assessments and follow-up in the Treatment and Placebo groups (p<0.05).

CONCLUSION

ear acupuncture was efficacious in reducing disability and increasing tissue temperature in people with chronic pain in the spinal column. Brazilian Register of Clinical Trials (RBR-5X69X2).

The Role of Ventral Tegmental Area Gamma-Aminobutyric Acid in Chronic Neuropathic Pain after Spinal Cord Injury in Rats

Spinal cord injury (SCI) frequently results in chronic neuropathic pain (CNP). However, the understanding of brain neural circuits in CNP modulation is unclear. The present study examined the changes of ventral tegmental area (VTA) putative GABAergic and dopaminergic neuronal activity with CNP attenuation in rats. SCI was established by T10 clip compression injury (35 g, 1 min) in rats, and neuropathic pain behaviors, in vivo extracellular single-cell recording of putative VTA gamma-aminobutyric acid (GABA)/dopamine neurons, extracellular GABA level, glutamic acid decarboxylase (GAD), and vesicular GABA transporters (VGATs) were measured in the VTA, respectively. The results revealed that extracellular GABA level was significantly increased in the CNP group (50.5 ± 18.9 nM) compared to the sham control group (10.2 ± 1.7 nM). In addition, expression of GAD_65/67, c-Fos, and VGAT exhibited significant increases in the SCI groups compared to the sham control group. With regard to neuropathic pain behaviors, spontaneous pain measured by ultrasound vocalizations (USVs) and evoked pain measured by paw withdrawal thresholds showed significant alteration, which was reversed by intravenous (i.v.) administration of morphine (0.5-5.0 mg/kg). With regard to in vivo electrophysiology, VTA putative GABAergic neuronal activity (13.6 ± 1.7 spikes/sec) and putative dopaminergic neuronal activity (2.4 ± 0.8 spikes/sec) were increased and decreased, respectively, in the SCI group compared to the sham control group. These neuronal activities were reversed by i.v. administration of morphine. The present study suggests that chronic increase of GABAergic neuronal activity suppresses dopaminergic neuronal activity in the VTA and is responsible for negative emotion and motivation for attenuation of SCI-induced CNP.