Chronic low back pain and the transdiagnostic process: How do cognitive and emotional dysregulations contribute to the intensity of risk factors and pain?

Adverse Childhood Experiences and Chronic Low Back Pain in Adulthood: The Role of Emotion Regulation

Chronic low back pain (cLBP) is characterized by biopsychosocial determinants that collectively result in a substantial burden at the individual, community, and health care system levels. A growing body of literature suggests that childhood adversity is longitudinally associated with the development and maintenance of various chronic pain conditions in adulthood. Little research has investigated the psychological processes that might underlie the association between adverse childhood experiences (ACEs) and cLBP. Emotion regulation comprises a substantive part of the subjective experience of pain and may be a potential mechanism through which ACEs contribute to cLBP etiology and maintenance. Thus, the current study examined the extent to which emotion dysregulation mediated the relationship between ACEs and pain severity (pain at rest and movement-evoked pain) in adults with cLBP. Participants included 183 adults (53.0% female, 62.5% non-Hispanic Black) between the ages of 18 and 85 with cLBP. Participants self-reported on ACEs, pain, difficulties in emotion regulation (DER), depression, and completed brief physical function tasks. In data analytic models, sociodemographic variables were included as covariates. Analyses revealed that emotion regulation mediated the relationship between ACEs and cLBP severity at rest (indirect effect = .15 [95% CI {.06-.25}]) and with movement (indirect effect = 1.50 [95% CI {.69-2.57}]). Findings suggest ACEs are linked to cLBP severity in adulthood through DER. This aligns with research demonstrating that childhood maltreatment can lead to DER, which perpetuate over the lifespan to impact adult health outcomes. PERSPECTIVE: This study presents emotion dysregulation as a psychological pathway through which childhood adversity may contribute to cLBP in adulthood. This work may bolster our understanding of social experiences as risk factors for chronic pain, while identifying targets for clinical intervention. TRIAL REGISTRATION: This study utilized baseline data collected as part of a parent trial titled "Examining Racial and SocioEconomic Disparities in Chronic Low Back Pain" (ClinicalTrials.gov ID: NCT03338192).

Abnormal brain activity in lumbar disc herniation patients with chronic pain is associated with their clinical symptoms

Introduction

Lumbar disc herniation, a chronic degenerative disease, is one of the major contributors to chronic low back pain and disability. Although many studies have been conducted in the past on brain function in chronic low back pain, most of these studies did not classify chronic low back pain (cLBP) patients according to their etiology. The lack of etiologic classification may lead to inconsistencies between findings, and the correlation between differences in brain activation and clinical symptoms in patients with cLBP was less studied in the past.

Methods

In this study, 36 lumbar disc herniation patients with chronic low back pain (LDHCP) and 36 healthy controls (HCs) were included to study brain activity abnormalities in LDHCP. Visual analogue scale (VAS), oswestry disability index (ODI), self-rating anxiety scale (SAS), self-rating depression scale (SDS) were used to assess clinical symptoms.

Results

The results showed that LDHCP patients exhibited abnormally increased and diminished activation of brain regions compared to HCs. Correlation analysis showed that the amplitude of low frequency fluctuations (ALFF) in the left middle frontal gyrus is negatively correlated with SAS and VAS, while the right superior temporal gyrus is positively correlated with SAS and VAS, the dorsolateral left superior frontal gyrus and the right middle frontal gyrus are negatively correlated with VAS and SAS, respectively.

Conclusion

LDHCP patients have brain regions with abnormally increased and abnormally decreased activation compared to healthy controls. Furthermore, some of the abnormally activated brain regions were correlated with clinical pain or emotional symptoms.

Machine learning algorithms distinguish discrete digital emotional fingerprints for web pages related to back pain

Back pain is the leading cause of disability worldwide. Its emergence relates not only to the musculoskeletal degeneration biological substrate but also to psychosocial factors; emotional components play a pivotal role. In modern society, people are significantly informed by the Internet; in turn, they contribute social validation to a "successful" digital information subset in a dynamic interplay. The Affective component of medical pages has not been previously investigated, a significant gap in knowledge since they represent a critical biopsychosocial feature. We tested the hypothesis that successful pages related to spine pathology embed a consistent emotional pattern, allowing discrimination from a control group. The pool of web pages related to spine or hip/knee pathology was automatically selected by relevance and popularity and submitted to automated sentiment analysis to generate emotional patterns. Machine Learning (ML) algorithms were trained to predict page original topics from patterns with binary classification. ML showed high discrimination accuracy; disgust emerged as a discriminating emotion. The findings suggest that the digital affective "successful content" (collective consciousness) integrates patients' biopsychosocial ecosystem, with potential implications for the emergence of chronic pain, and the endorsement of health-relevant specific behaviors. Awareness of such effects raises practical and ethical issues for health information providers.

Somatosensory amplification moderates the efficacy of internet-delivered CBT for somatic symptom distress in emerging adults: Exploratory analysis of a randomized controlled trial

OBJECTIVE

While studies mainly provide positive evidence for the efficacy of internet-delivered cognitive-behavioral therapy (ICBT) for various persistent somatic symptoms, it remains largely unclear for whom these interventions work or not. This exploratory analysis aimed to identify moderators for the outcome between ICBT for somatic symptom distres and a waitlist control group (WL) in a vulnerable target group of emerging adults.

METHODS

Based on data from a randomized controlled trial on 156 university students with varying degrees of somatic symptom distress who were allocated to either an eight-week, therapist guided ICBT (iSOMA) or to the WL, we examined pretreatment demographic characteristics, health-related variables (e.g., somatic symptom duration), mental distress (e.g., depression, anxiety) and cognitive-emotional factors (emotional reactivity, somatosensory amplification) as candidate moderators of the outcome, somatic symptom distress (assessed by the Patient Health Questionnaire, PHQ-15) from pre- to posttreatment.

RESULTS

Somatosensory amplification (assessed by the Somatosensory Amplification Scale, SSAS) moderated the outcome in favor of iSOMA (B = -0.17, SE = 0.08, p = 0.031), i.e., higher pretreatment somatosensory amplification was associated with better outcome in the active compared to the control intervention. No significant moderation effects were found among demographic characteristics, health-related variables, or mental distress.

CONCLUSION

Our findings suggest that an internet-delivered CBT for somatic symptom distress should be preferred over no active treatment particularly in individuals with moderate to high levels of somatosensory amplification, which as a next step should be tested against further treatments and in clinical populations.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS00014375).

Amygdala functional connectivity mediates the association between catastrophizing and threat-safety learning in youth with chronic pain

ABSTRACT

There is a need to identify brain connectivity alterations predictive of transdiagnostic processes that may confer vulnerability for affective symptomology. Here, we tested whether amygdala resting-state functional connectivity (rsFC) mediated the relationship between catastrophizing (negative threat appraisals and predicting poorer functioning) and altered threat-safety discrimination learning (critical to flexibly adapt to new and changing environments) in adolescents with persistent pain. We examined amygdala rsFC in 46 youth with chronic pain and 29 healthy peers (age M = 15.8, SD = 2.9; 64 females) and its relationship with catastrophizing and threat-safety learning. We used a developmentally appropriate threat-safety learning paradigm and performed amygdala seed-based rsFC and whole-brain mediation analyses. Patients exhibited enhanced connectivity between the left amygdala and right supramarginal gyrus (SMG) (cluster-level P-FDR < 0.05), whereas right amygdala rsFC showed no group differences. Only in patients, elevated catastrophizing was associated with facilitated threat-safety learning (CS+>CS-; rp = 0.49, P = 0.001). Furthermore, in patients, elevated catastrophizing was associated with reduced left amygdala connectivity with SMG / parietal operculum, and increased left amygdala connectivity with hippocampus, dorsal striatum, paracingulate, and motor regions (P < 0.001). In addition, blunted left amygdala rsFC with right SMG/parietal operculum mediated the association between catastrophizing and threat-safety learning (P < 0.001). To conclude, rsFC between the left amygdala (a core emotion hub) and inferior parietal lobe (involved in appraisal and integration of bodily signals and attentional reorienting) explains associations between daily-life relevant catastrophizing and threat-safety learning. Findings provide a putative model for understanding pathophysiology involved in core psychological processes that cut across diagnoses, including disabling pain, and are relevant for their etiology.

Assessing Multisensory Sensitivity Across Scales: Using the Resulting Core Factors to Create the Multisensory Amplification Scale

Multisensory sensitivity (MSS), observed in some chronic pain patients, may reflect a generalized central nervous system sensitivity. While several surveys measure aspects of MSS, there remains no gold standard. We explored the underlying constructs of 4 MSS-related surveys (80 items in total) using factor analyses using REDCap surveys (N = 614, 58.7% with pain). Four core- and 6 associated-MSS factors were identified from the items assessed. None of these surveys addressed all major sensory systems and most included additional related constructs. A revised version of the Somatosensory Amplification Scale was developed, encompassing 5 core MSS systems: vision, hearing, smell, tactile, and internal bodily sensations: the 12-item Multisensory Amplification Scale (MSAS). The MSAS demonstrated good internal consistency (alpha = 0.82), test-retest reliability (ICC3,1 = 0.90), and construct validity in the original and in a new, separate cohort (R = 0.54-0.79, P < .0001). Further, the odds of having pain were 2-3.5 times higher in the highest sex-specific MSAS quartile relative to the lowest MSAS quartile, after adjusting for age, sex, BMI, and pain schema (P < .03). The MSAS provides a psychometrically comprehensive, brief, and promising tool for measuring the core-dimensions of MSS. PERSPECTIVE: Multiple multisensory sensitivity (MSS) tools are used, but without exploration of their underlying domains. We found several measures lacking core MSS domains, thus we modified an existing scale to encompass 5 core MSS domains: light, smell, sound, tactile, and internal bodily sensations using only 12 items, with good psychometric properties.

Understanding Pain Catastrophizing: Putting Pieces Together

The present narrative review addresses issues concerning the defining criteria and conceptual underpinnings of pain catastrophizing. To date, the concept of pain catastrophizing has been extensively used in many clinical and experimental contexts and it is considered as one of the most important psychological correlate of pain chronicity and disability. Although its extensive use, we are still facing important problems related to its defining criteria and conceptual understanding. At present, there is no general theoretical agreement of what catastrophizing really is. The lack of a consensus on its definition and conceptual issues has important consequences on the choice of the pain management approaches, defining and identifying problems, and promoting novel research. Clinical and research work in absence of a common theoretical ground is often trivial. It is very surprising that clinical and experimental work has grown extensively in the past years, without a common ground in the form of a clear definition of pain catastrophizing and overview of its conceptual basis. Improving the efficacy and efficiency of pan catastrophizing related treatments requires an understanding of the theoretical construct. So far, most interventions have only demonstrated modest effects in reducing pain catastrophizing. Therefore, clarifying the construct may be an important precursor for developing more targeted and effective interventions, thereby easing some of the burden related to this aspect of pain. In our review, we have extracted and de-constructed common elements that emerge from different theoretical models with the aim to understand the concept of catastrophizing, which components can be modulated by psychological interventions, and the general role in pain processing. The analysis of the literature has indicated essential key elements to explain pain catastrophizing: emotional regulation, catastrophic worry (as repetitive negative thinking), rumination, behavioral inhibition and behavioral activation (BIS/BAS) systems, and interoceptive sensitivity. The present paper attempts to integrate these key elements with the aim to re-compose and unify the concept within a modern biopsychosocial interpretation of catastrophizing.

Exploring transdiagnostic processes for chronic pain and opioid misuse among two studies of adults with chronic pain

Chronic pain is a significant public health problem associated with functional impairment, increased medical expenditures, and opioid misuse. Recent work has suggested that certain transdiagnostic psychosocial factors may be more important than pain intensity to better understand pain and opioid outcomes. Specifically, pain-related anxiety, anxiety sensitivity, emotion dysregulation, and distress tolerance have all been uniquely associated with both pain and opioid outcomes across a range of samples. Yet, no work has examined how these transdiagnostic constructs relate to pain and opioid misuse when accounting for the other constructs. Therefore, the current study employed two independent sample of adults with chronic pain to examine (1) the construct independence of each of these factors using exploratory structural equation modelling (ESEM) and (2) how each of these constructs relates to pain and opioid outcomes in latent structural models. Results from Study 1 provided empirical support for construct independence of the transdiagnostic constructs. Findings from Study 2 indicated that pain-related anxiety was most strongly related to pain intensity, interference, and pain-related negative affect, anxiety sensitivity with opioid misuse, and emotion dysregulation with all studied criterion variables. The current results highlight the importance of assessing and targeting transdiagnostic constructs among adults with pain.

Pain Experiences and Their Relation to Opioid Misuse Risk and Emotion Dysregulation

Pain is a complex, multidimensional experience but often is measured as a unidimensional experience. This study aimed to separately assess the sensory and affective components of pain and identify their relations to important pain-related outcomes, particularly in terms of opioid misuse risk and emotion dysregulation among patients with chronic pain receiving treatment in Appalachia. Two hundred and twelve patients presenting to a multidisciplinary pain center completed the Difficulties in Emotion Regulation Scale (DERS-18), Screener and Opioid Assessment for Patients with Pain-Revised (SOAPP-R), and short-form McGill Pain Questionnaire (SF-MPQ). The sensory experience of pain was unrelated to emotion dysregulation (r = 0.06, p = 0.57) and weakly related to opioid misuse risk (r = 0.182, p < 0.05). In contrast, the affective experience of pain was moderately related to emotion dysregulation (r = 0.217, p < 0.05) and strongly related to opioid misuse risk (r = 0.37, p < 0.01). In addition, emotion dysregulation predicted variance in opioid misuse risk above and beyond the affective and sensory experiences of pain ((b = 0.693, p < 0.001). The results suggest patients with a strong affective experience versus sensory experience of pain and challenges with emotion regulation may require a more comprehensive intervention to address these underlying components in order to reduce their risk of misusing opioid medications.

Multisensory Sensitivity is Related to Deep-Tissue but Not Cutaneous Pain Sensitivity in Healthy Individuals

PURPOSE

Some individuals with chronic pain find daily life sensations (eg, noise, light, or touch) aversive. This amplification of multisensory sensations has been associated with centrally mediated plasticity; for example, greater multisensory sensitivity (MSS) occurs in patients with fibromyalgia than rheumatoid arthritis. However, whether MSS preferentially relates to pain measures which reflect central influences (eg, dynamic quantitative sensory testing (QST) or referred pain), or whether the MSS-pain relationship requires priming from chronic pain, is unknown. Thus, this cross-sectional study investigated the relationships between MSS assessed in a pain-free state and evoked pain sensitivity.

METHODS

Experimental intramuscular infusion pain and multiple static and dynamic QST were assessed in 465 healthy, pain-free adults: pain thresholds using pressure (PPTs) and heat (HPTs), temporal summation of pain (TSP) using pressure, heat or punctate stimuli, and conditioned pain modulation (CPM) using pressure or heat test stimuli. MSS was assessed using 7 items from Barsky's Somatosensory Amplification Scale. Differences in pain and QST between sex-specific MSS quartiles were assessed, adjusting for multiple comparisons. All participants completed at least one intramuscular infusion condition, but not all were asked to complete each QST (n=166-465).

RESULTS

Both static and dynamic QST differed between highest and lowest MSS quartiles using pressure stimuli: lower PPTs (adjusted-p<0.01); increased pressure TSP (adjusted-p=0.02); lower pressure CPM (adjusted-p=0.01). However, none of the heat or punctate QST measures (HPTs, TSP, or CPM) differed between MSS quartiles (adjusted-p>0.05). Odds of experiencing TSP or referred pain was not greater, whereas CPM was 8-fold less likely, in those with highest MSS.

CONCLUSION

Normal variation in non-noxious MSS is related to both static and dynamic pain sensitivity, without sensitization associated with chronic pain, but is dependent on the QST stimulus. Thus, common influences on MSS and pain sensitivity may involve central mechanisms but are likely more complex than previously recognized.

The mechanisms of pain tolerance and pain-related anxiety in acute pain

This study emphasizes the role of pain catastrophizing and state anxiety on pain tolerance and pain-related anxiety. Response expectancies for pain tolerance and pain intensity were tested as potential mediators. A cold-pressor task was used on a healthy sample. Measures were taken before and after cold-pressor procedure, while aversive versus neutral information regarding the cold-pressor task was given prior to the pain induction. An exploratory path model was conducted. Similar paths for pain tolerance and for pain-related anxiety were shown in aversive condition. Also, psychological measures may explain pain experience in aversive context.

Is the widely used two-factor structure of the Ruminative Responses Scale invariant across different samples of women?

OBJECTIVES

Although the Ruminative Responses Scale is one of the most widely used measures of rumination, its two-factor structure remains controversial. Taking this into account, we aimed to test the RRS-10 two-factor invariance (Brazilian version) between different samples of women and to study its internal consistency and convergent validity.

METHODS

A sample of 321 women (general population, n = 106; college students, n = 115; and medical population of patients with overweight and obesity, n = 100) participated in the study. The two-factor structure of RRS-10 was assessed by CFA and multigroup analysis using Mplus software. Internal consistency was assessed by Cronbach's alpha and the convergent validity by Pearson correlations.

RESULTS

The two-factor structure of RRS-10 showed a good fit, factorial invariance across three samples, good internal consistency, and adequate convergent validity. Brooding and Reflection subscales were both positively correlated with psychological inflexibility, cognitive fusion, anxiety, depression, and stress symptoms, although Brooding presented significantly stronger associations with these variables than Reflection.

CONCLUSIONS

This study provides further discussion and evidence regarding the RRS-10 two-factor structure, as well as a valid version of RRS-10 to use in Brazil in order to reliably assess rumination in medical and research settings.

PRACTITIONER POINTS

This is the first study to test and confirm the RRS two-factor structure invariance across groups. RRS-10 two-dimensionality was confirmed in medical and non-medical samples of women. Brooding subscale showed significantly stronger relationships with psychopathology and experiential avoidance than Reflection. The study provides evidence that RRS can be used as a valid and sound measure to accurately assess the clinically relevant dimensions of rumination simultaneously across distinct groups.

Plasma N-glycome composition associates with chronic low back pain

BACKGROUND

Low back pain (LBP) is the symptom of a group of syndromes with heterogeneous underlying mechanisms and molecular pathologies, making treatment selection and patient prognosis very challenging. Moreover, symptoms and prognosis of LBP are influenced by age, gender, occupation, habits, and psychological factors. LBP may be characterized by an underlying inflammatory process. Previous studies indicated a connection between inflammatory response and total plasma N-glycosylation. We wanted to identify potential changes in total plasma N-glycosylation pattern connected with chronic low back pain (CLBP), which could give an insight into the pathogenic mechanisms of the disease.

METHODS

Plasma samples of 1128 CLBP patients and 760 healthy controls were collected in clinical centers in Italy, Belgium and Croatia and used for N-glycosylation profiling by hydrophilic interaction ultra-performance liquid chromatography (HILIC-UPLC) after N-glycans release, fluorescent labeling and clean-up. Observed N-glycosylation profiles have been compared with a cohort of 126 patients with acute inflammation that underwent abdominal surgery.

RESULTS

We have found a statistically significant increase in the relative amount of high-branched (tri-antennary and tetra-antennary) N-glycan structures on CLBP patients' plasma glycoproteins compared to healthy controls. Furthermore, relative amounts of disialylated and trisialylated glycan structures were increased, while high-mannose and glycans containing bisecting N-acetylglucosamine decreased in CLBP.

CONCLUSIONS

Observed changes in CLBP on the plasma N-glycome level are consistent with N-glycosylation changes usually seen in chronic inflammation.

GENERAL SIGNIFICANCE

To our knowledge, this is a first large clinical study on CLBP patients and plasma N-glycome providing a new glycomics perspective on potential disease pathology.