Catastrophizing Interferes with Cognitive Modulation of Pain in Women with Fibromyalgia

Choosing the optimal target area for repeated transcranial magnetic stimulation in treating neuropathic pain in spinal cord injury patients: a comparative analysis

Objective

The specific target area of repeated transcranial magnetic stimulation (rTMS) in treating neuropathic pain resulting from spinal cord injury (SCI-NP) remains uncertain.

Methods

Thirty-four participants with SCI-NP were allocated into three groups, namely, the motor cortex (M1, A) group, the left dorsolateral prefrontal cortex (LDLPFC, B) group, and the control (sham stimulation, C) group. The intervention was administered totally 10 times. Outcome measures assessed pre-(T0) and post-(T1)intervention, including Numerical Rating scale (NRS), anxiety (SAS), depression (SDS), sleep quality (PSQI), brief pain inventory (BPI), and impression of change.

Results

All outcomes in groups A and B significantly changed after intervention (p < 0.05), and the delta value (T1-T0) also significantly changed than group C (p < 0.05). The delta value of SDS in the group B was better than the group A, and the change of pain degree in the group B was moderately correlated with the change in PSQI (r = 0.575, p < 0.05). Both patients in the groups A and B showed significant impression of change about their received therapy (p < 0.05).

Conclusion

Both targets are effective, but LDLPFC is more effective in reducing depression in SCI-NP. Healthcare providers might select the suitable area according to the specific attributes of their patients.

Evaluating the Interaction Between Pain Intensity and Resilience on the Impact of Pain in the Lives of People With Fibromyalgia

OBJECTIVE

Recent theoretical models posit that resilience acts as a resource/mechanism opposing pain catastrophizing and other vulnerability sources against pain adaptation. The aim of this study was to investigate the relationship between resilience, pain, and functionality in people living with fibromyalgia (FM).

MATERIALS AND METHODS

We conducted a cross-sectional online survey of people participating in Brazilian fibromyalgia virtual support groups on Facebook in May 2018. Resilience was evaluated by the Connor-Davidson Resilience Scale. Average pain and the degree of interference of pain in the lives of participants (DIPLP) were assessed using the Brief Pain Inventory. The association between these 3 variables was evaluated through multivariable robust linear regression with adjustment for 21 potential confounders.

RESULTS

We included 2176 participants with FM. Resilience was associated with a decreased DIPLP (β: -0.38, 95% CI: -0.54 to -0.22, P <0.001) but not with average pain scores (β: -0.01, 95% CI: -0.18 to 0.16, P =0.93). A significant interaction between resilience and average levels of pain on the DIPLP was observed so that resilience showed a much stronger protective association among participants with average null-to-mild pain than among those with moderate and severe pain levels.

DISCUSSION

Our results provide evidence against beliefs that the pain of people with FM is related to low psychological resilience and shed light on the complex interrelationships between resilience, pain, and functionality. This research signals both the relevance and limits of resilience in the management of FM. Future studies evaluating behavioral interventions for FM should consider how those interventions interact with baseline pain levels and resilience.

How to Generate Self-Efficacy despite Pain: The Role of Catastrophizing and Avoidance in Women with Fibromyalgia

BACKGROUND AND OBJECTIVE

Fibromyalgia-related pain is influenced by numerous factors, including severity, as well as cognitive profiles based on pain catastrophizing or activity patterns. In this context, self-efficacy is identified as a potential predictor for explaining certain health outcomes. This study aimed to contribute to exploring the role of pain avoidance (as activity pattern) between pain severity and self-efficacy along pain catastrophizing.

METHODS

Through a cross-sectional study, a total of 264 women with fibromyalgia completed self-report measures of pain severity, pain avoidance, pain catastrophizing, and self-efficacy. The severity of the symptoms, the time elapsed since diagnosis, and the time elapsed since the onsets of symptoms were included as covariates to control. Regression-based moderated-mediation analysis was used to test the conditional effect of pain severity on self-efficacy via pain avoidance at varying levels of pain catastrophizing.

RESULTS

Pain avoidance mediated the effect of pain severity on self-efficacy. The indirect effects showed a moderated effect when patients scored high on the pain catastrophizing scale. The model evaluated, where catastrophic pain moderates the indirect effect of pain intensity on self-efficacy through pain avoidance, explained 49% of the variance.

CONCLUSIONS

Catastrophic beliefs associated with pain as being uncontrollable increase the relationship between pain severity and pain avoidance. In turn, pain avoidance is associated with a low perception of capacity.

Clinical Phenomenology of Fibromyalgia Syndrome in Male Patients: Same But Different

The majority of knowledge about fibromyalgia syndrome (FMS) derives from studies of female patients. Little is known about the clinical characteristics and treatment outcomes of male patients with FMS. In this retrospective cohort study with a prospective posttreatment follow-up, we investigated whether male patients with FMS differ from female patients in terms of 1) symptom burden, 2) psychological characteristics, and 3) clinical treatment response. We identified 263 male (4%) out of 5,541 patients with FMS completing a 3-week multimodal pain-treatment program. Male patients (51.3 ± 9.1 years) were age- and time-matched (1:4) with female patients (N = 1,052, 51.3 ± 9.0 years). Data on clinical characteristics, psychological comorbidities, and treatment responses were obtained from medical records and validated questionnaires. Levels of perceived pain, psychological comorbidity, and functional capacity were similar between genders, although male patients with FMS showed a higher prevalence of alcohol abuse. Compared to female patients, male patients experienced themselves less often as overly accommodating (Cohen's d = -.42) but more often as self-sacrificing (d = .26) or intrusive (d = .23). Regarding pain coping, male patients were less likely to utilize mental distraction, rest- and relaxation techniques, or counteractive activities (d = .18-.27). Male patients showed a slightly worse overall response rate than women (69% vs 77%), although differences between individual outcome measures were small (d < .2). Although male and female patients in our cohort were similar in clinical presentation and treatment response, the gender-specific differences in interpersonal problems and pain coping suggest consideration of these aspects in the treatment of male patients with FMS. PERSPECTIVE: Knowledge about fibromyalgia mostly derives from studies of female patients. Identifying and understanding gender-specific differences in fibromyalgia is an important roadmap in the treatment of this syndrome by focusing on specific gender aspects such as differences in interpersonal problems and pain coping mechanisms.

Pain Catastrophizing as a Mediator Between Pain Self-Efficacy and Disease Severity in Patients with Fibromyalgia

BACKGROUND

Fibromyalgia (FM) is characterized by chronic widespread pain, fatigue, sleep disturbances, cognitive impairment, and mood disturbance. Both pain catastrophizing and pain self-efficacy have been found to be mediators of pain treatment effectiveness. However, whether pain catastrophizing mediates the association between pain self-efficacy and FM severity remains unclear.

AIM

To examine whether pain catastrophizing mediates the association between pain self-efficacy and disease severity in patients with FM.

METHODS

This cross-sectional study included the baseline data of 105 people with FM from a randomized controlled trial. Hierarchical linear regression analysis was performed to examine the predictive ability of pain catastrophizing for FM severity. Furthermore, we examined the mediating effect of pain catastrophizing on the association between pain self-efficacy and FM severity.

RESULTS

Pain self-efficacy was negatively associated with pain catastrophizing (β = -.4043, p < .001). FM severity was positively associated with pain catastrophizing (β = .8290, p < .001) and negatively associated with pain self-efficacy (β = -.3486, p = .014). Pain self-efficacy had a direct effect on FM severity (β = -.6837, p < .001) and an indirect effect on FM severity through the effect of pain catastrophizing (β = -.3352, 95% CI bootstrapping -.5008 to -.1858).

CONCLUSION

Pain catastrophizing independently predicts FM severity and mediates the association between pain self-efficacy and FM severity. Pain catastrophizing should be monitored through interventions aimed at improving pain self-efficacy to reduce symptom burden in patients with FM.

Effect of Catastrophic Thinking on the Analgesic Effect of Electroacupuncture

Introduction

Patients with chronic pain and high-level catastrophic thoughts often do not respond to acupuncture. This may be related to hypofunctioning of the dorsolateral prefrontal cortex and the descending pain inhibitory system. Therefore, we examined the relationship between the level of catastrophic thinking and the analgesic effect of electroacupuncture using the pain catastrophizing scale (PCS). We also evaluated the descending pain inhibitory system using conditioned pain modulation (CPM) and offset analgesia (OA). The relationship between catastrophic thinking and the descending pain inhibitory system was also examined.

Materials and Methods

After testing the hospital anxiety and depression scale and the PCS in 14 healthy adults, the current pain threshold (CPT), CPM, and OA were measured, in order, before the intervention. Thereafter, electroacupuncture was applied to 3 limbs (the dominant hand and both lower extremities) at 4 Hz, and to the scalp at 100 Hz, for 30 minutes, and the CPT was measured again immediately after the intervention. The difference in the CPT before and after the intervention was taken as the analgesic effect.

Results

The participants were divided into 2 groups, the H-PCS group (≥16 points) and the L-PCS group (≤15 points), according to the PCS score, and the analgesic effects of electroacupuncture were significantly different (P = 0.04). However, no relationship was found between the PCS score and the CPM (r = -0.02, P = 0.94) and OA effects (r = -0.19, P = 0.49).

Conclusion

It was suggested that people with high-level catastrophic thinking may find it difficult to obtain the analgesic effects of electroacupuncture.

Women with fibromyalgia (ACR criteria) compared with women diagnosed by doctors and women with osteoarthritis: Cross-sectional study using functional and clinical variables

PURPOSE

To compare functional and clinical variables of women with fibromyalgia (American College of Rheumatology [ACR] criteria) vs women diagnosed by doctors and women with knee osteoarthritis (KOA).

METHODS

This is a cross-sectional study. We used clinical measures, namely, Widespread Pain Index (WPI), Symptom Severity Scale (SSS), Fibromyalgia Impact Questionnaire-Revised (FIQ-R), Numerical Pain Rating Scale (NPRS), Central Sensitization Inventory (CSI), Pain-Related Catastrophizing Thoughts Scale (PCTS), and functional measures, such as Sit-to-Stand (STS) test, and Timed Up and Go (TUG) test.

RESULTS

The sample consisted of 91 participants divided into 3 groups: participants with KOA (n = 30), fibromyalgia diagnosed according to the ACR (FM-ACR, n = 31), and fibromyalgia according to the medical diagnosis (FM-Med, n = 30). In the comparisons, we observed a significant difference (P < 0.05) and a large effect size (d ≥ 0.8), between all groups, in the WPI, WPI + SSS, FIQ-R domains, CSI, and PCTS. We did not observe significant values in the correlations between the clinical variables, SST, and TUG test.

CONCLUSION

People with fibromyalgia according, to the ACR, have higher levels of widespread pain, symptom severity, global impact on quality of life, central sensitization, and catastrophizing compared with people with knee OA and people with clinical fibromyalgia diagnosis not confirmed by the ACR diagnostic criteria.

Feldenkrais awareness though movement intervention for fibromyalgia syndrome: A proof-of-concept study

INTRODUCTION

The Feldenkrais Method® is a form of awareness through movement (ATM) aimed at improving spatial and kinesthetic awareness through verbally guided movements, in order to learn more effective actions.

METHOD

The present study, a proof-of-concept, observational, non-controlled prospective study, aims at exploring the effectiveness of ATM for fibromyalgia syndrome (FM), measuring the effect by means of multi-dimensional questionnaires, administered at baseline and after 4 months of ATM activity.

RESULTS

One hundred twenty-eight FM patients (mean age 54 years old, 2% males) participated in the study. A statistically significant improvement was found in FM-specific measures (Polysymptomatic Distress Scale, PDS) (p = 0.003) and the Pain Catastrophization Scale (PCS) (p = 0.020); coherently, the Revised Fibromyalgia Impact Questionnaire (FIQR) showed a trend in improvement after the intervention, although this improvement was not statistically significant. The logistic regression analysis found a correlation between PDS, fatigue and anxiety measures; PCS, years from diagnosis and anxiety.

CONCLUSION

ATM could improve FM-specific measures and pain-related catastrophizing. Further studies are needed to identify FM subgroups in order to find personalized targets that can be used to guide treatments.

Pain Control Beliefs Predict Premature Withdrawal From the Labor Market in Workers With Persistent Pain: Prospective Cohort Study With 11-Year Register Follow-up

While a range of work-related psychosocial factors has been associated with various pain disorders and early retirement, less is known about pain cognitions and their influence on premature exit from the labor market. Therefore, as a primary objective, this study investigates associations between pain control beliefs and risk of disability pension among Danish eldercare workers. In 2005, 2257 female eldercare workers with low-back and/or neck/shoulder pain>90 days within the previous 12 months, replied to a survey and were followed for 11 years in a national register of social transfer payments. Using Cox regression, we estimated the risk of disability pension during follow-up from experiencing different levels of "pain control" and "pain influence," controlling for pain intensity and other relevant confounders. In the fully adjusted model for pain control with "high" as reference, hazard ratios of 1.30 (95% CI 1.03-1.64) and 2.09 (95% CI 1.45-3.01) are observed for "moderate" and "low," respectively, while the metric of pain influence shows hazard ratios of 1.43 (95% CI 1.11-1.87) and 2.10 (1.53-2.89), respectively. Pain control beliefs are associated with disability pension among eldercare workers with persistent pain. These results highlight the importance of evaluating not only bodily manifestations of pain, but also individual pain-related cognitions that may influence the experience of pain. PERSPECTIVE: This article addresses the complex experience of pain within an organizational context. We introduce the metrics of "pain control" and "pain influence" among workers with persistent pain, showing that the psychometric properties of these measures are prospectively associated with premature exit from the labor market.

Dysfunctional Activation of the Dorsolateral Prefrontal Cortex During Pain Anticipation Is Associated With Altered Subsequent Pain Experience in Fibromyalgia Patients

The ability to accurately predict pain is an adaptive feature in healthy individuals. However, in chronic pain, this mechanism may be selectively impaired and can lead to increased anxiety and excessive avoidance behavior. Recently, we reported the first data demonstrating brain activation in fibromyalgia (FM) patients during conditioned pain responses, in which FM patients revealed a tendency to form new pain-related associations rather than extinguishing irrelevant ones. The aim of the present study was to extend our previous analysis, to elucidate potential neural divergences between subjects with FM (n = 65) and healthy controls (HCs) (n = 33) during anticipatory information (ie, prior to painful stimulus onset). Using functional magnetic resonance imaging (fMRI), the current analyses include 1) a congruently cued paradigm of low and high pain predictive cues, followed by 2) an incongruently cued paradigm where low and high pain predictive cues were followed by an identical mid-intensity painful pressure. During incongruently cued high-pain associations, FM exhibited reduced left dorsolateral prefrontal cortex (dlPFC) activation compared to HCs, which was followed by an altered subsequent pain experience in FM, as patients continued to rate the following painful stimuli as high, even though the pressure had been lowered. During congruently cued low pain anticipation, FM exhibited decreased right dlPFC activation compared to HCs, as well as decreased brain connectivity between brain regions implicated in cognitive modulation of pain (dlPFC) and nociceptive processing (primary somatosensory cortex/postcentral gyrus [S1] and supplementary motor area [SMA]/midcingulate cortex [MCC]). These results may reflect an important feature of validating low pain expectations in HCs and help elucidate behavioral reports of impaired safety processing in FM patients. PERSPECTIVE: FM exhibited a stronger conditioned pain response for high-pain associations, which was associated with reduced dlPFC activation during the incongruent trial. During (congruent and incongruent) low pain associations, FM dlPFC brain activation remained indifferent. Imbalances in threat and safety pain perception may be an important target for psychotherapeutic interventions.

Neurophysiological and Psychosocial Mechanisms of Fibromyalgia: A Comprehensive Review and Call for An Integrative Model

Research into the neurobiological and psychosocial mechanisms involved in fibromyalgia has progressed remarkably in recent years. Despite this, current accounts of fibromyalgia fail to capture the complex, dynamic, and mutual crosstalk between neurophysiological and psychosocial domains. We conducted a comprehensive review of the existing literature in order to: a) synthesize current knowledge on fibromyalgia; b) explore and highlight multi-level links and pathways between different systems; and c) build bridges connecting disparate perspectives. An extensive panel of international experts in neurophysiological and psychosocial aspects of fibromyalgia discussed the collected evidence and progressively refined and conceptualized its interpretation. This work constitutes an essential step towards the development of a model capable of integrating the main factors implicated in fibromyalgia into a single, unified construct which appears indispensable to foster the understanding, assessment, and intervention for fibromyalgia.

Exploring pain catastrophizing and its associations with low disease activity in rheumatic inflammatory disorders

Pain catastrophizing is a maladaptive mechanism associated with the exaggerated experience of pain, increased rumination and feelings of helplessness. The main objective of this study was to explore whether increased pain catastrophizing is independently associated with a lower proportion of low disease activity (LDA) in rheumatoid arthritis (RA), psoriatic arthritis (PsA) and axial spondylarthritis (axSpA). Demographics, comorbidities, treatment, disease activity measures and patient-reported outcome data were recorded in RA, PsA and axSpA patients. Pain catastrophizing score (PCS) was assessed using a standardised questionnaire. For each diagnosis, composite disease activity scores with distinct cut-off values for LDA, i.e. DAS28-CRP (RA), DAPSA (PsA) and ASDAS-CRP (axSpA) were calculated and used as the dependent variable in logistic regression reflecting LDA achieved. A total of one thousand two hundred and twenty nine patients were included: 580 with RA, 394 with PsA and 255 with axSpA. In the multivariable analysis, pain catastrophizing was independently associated with LDA rates in axSpA (OR 0.33, 95% CI [0.12, 0.88]) amongst tested groups. In RA (OR 0.90, 95% CI [0.64, 1.28]) and PsA (OR 0.77, 95% CI [0.55, 1.07]), a statistically significant association was not observed. Higher PCS was independently associated with not achieving LDA in axSpA. Our data, however, indicate that pain catastrophizing, which also reflects a patient's personality traits and coping abilities, plays a less important role for the patient than general pain perception.

Oral Health-Related Quality of Life among Chinese Chronic Orofacial Pain Patients with Psychological Health Problems: A Moderated Mediation Model

Psychological therapies are important for comprehensive chronic orofacial pain (COFP) treatment. This study is to validate the effects of psychological factors on oral health-related quality of life (OHRQoL) among COFP patients in China. Pain catastrophizing, which is a subjective cognitive emotion used to manage the psychological aspects of pain among COFP patients, was examined in relation to COFP severity and OHRQoL. All 479 participants were recruited in Changsha, Hunan Province, China. Cronbach's alpha coefficients (0.868-0.960), composite reliability scores (0.924-0.969), and average variance extracted from each construct (0.555-0.753) all indicated a good model fit. Pearson's correlation analysis showed that age and education status have a positive correlation with COFP severity, pain catastrophizing, and anxiety. COFP severity was related to anxiety, depression, and COFP-OHRQoL. Pain catastrophizing was related to employment status. Anxiety and depression symptoms indirectly mediated the correlation between COFP severity and COFP-OHRQoL. As a second-stage moderator, pain catastrophizing moderated the mediating effects of anxiety symptoms and depression symptoms. Our findings suggest that anxiety, depression, and pain catastrophizing should be evaluated jointly to improve COFP-OHRQoL among COFP patients. This evidence will help therapists to comprehensively treat patients for the best treatment effect.

The role of catastrophizing in chronic cyclical pelvic pain: A systematic review and meta-analysis

BACKGROUND

Dysmenorrhea (painful menstrual cramps) is one of the most common gynecological complaints in women and girls. Dysmenorrhea may be a condition itself or a result of another medical condition, including endometriosis and chronic pelvic pain. Research examining the relationship between menstrual pain ratings and catastrophizing has produced mixed results.

OBJECTIVE

To review and meta-analyze the relationship between catastrophizing and pain ratings of chronic cyclical pelvic pain.

DESIGN

Cross-sectional, longitudinal, and intervention studies that reported the relationship between menstrual/pelvic pain and catastrophizing were included. Study populations had to include healthy menstruating persons or persons with a condition associated with cyclical pelvic pain including primary dysmenorrhea, endometriosis, and/or chronic pelvic pain.

DATA SOURCES AND METHODS

A systematic search of articles published since 2012 on PubMed, PsychInfo, CINHAL, and Medline was conducted in January and rerun in November of 2022. Search terms included cyclical pelvic pain, dysmenorrhea, endometriosis, pelvic pain, and catastrophizing. Data extraction was completed independently by two extractors and cross-checked for errors. A random-effects meta-regression was used to synthesize the data using restricted maximum likelihood.

RESULTS

Twenty-five studies examining 4,540 participants were included. A random effects model found a meta-correlation between catastrophizing and pain of r = .31 (95% confidence interval: .23-.40) p < .001. Heterogeneity was large and significant (I2 = 84.5%, Q(24) = 155.16, p < .001). Studies that measured general pelvic pain rather than cyclical pelvic pain specifically and those that used multi-item rather than single-item measures of pain had significantly higher correlations. Age and depression did not moderate the relationship between catastrophizing and pain.

CONCLUSION

A systematic review and meta-analysis found that catastrophizing had a small but significant positive association with pain ratings. Patients experiencing cyclical pelvic pain may benefit from interventions targeting the psychological management of pain.

REGISTRATION

This meta-analysis was registered in PROSPERO on 14 January 2022. Registration number: CRD42022295328.

Effects of Walking as Physical Exercise on Functional Limitation through Pain in Patients with Fibromyalgia-How Does Catastrophic Thinking Contribute?

Background: Aerobic exercise has a beneficial impact on physical and mental health. However, patients with fibromyalgia do not always report perceiving these improvements. Objective: The aim of this study was to examine whether catastrophic thinking moderated the effects of perceived pain severity once an active and regular lifestyle had been established on functional limitation in chronic pain patients, in particular in fibromyalgia patients. Methods: The sample consisted of a total of 491 women with fibromyalgia diagnosed according to the criteria of the American College of Rheumatology. Participants completed an ad-hoc item about lifestyle related to walking pattern, the Brief Pain Inventory, the Pain Catastrophization Scale, and the Fibromyalgia Impact Questionnaire-Revised. To examine the relationship between the variables, a moderate mediation analysis was performed through the macro PROCESS (model 14). Results: The relationship between the performance of the recommended walking pattern and functional limitation was mediated by the severity of pain (B = −5.19, SE = 1.59, t = −3.25, 95% CI = [−4.06, −0.28], p < 0.001). Furthermore, it was found that the mediating effect of pain severity was moderated by catastrophic thinking (Index = −0.014, SE = 0.007, 95% CI [0.002, 0.030]). Conclusions: The positive effect of walking on functionality through the reduction of pain levels is favored when patients present low catastrophizing, which affects the relevance of including interventions focused on the reduction of catastrophizing in the prescription of physical exercise in patients with fibromyalgia as the treatment of choice.

Impact of resilience on disease severity and psychiatric comorbidities in patients with fibromyalgia

Background

Resilience is the process of adjusting successfully in the face of adversity, trauma, threats, or severe stress, such as serious health problems. It is one of the factors that affect recovery from psychiatric disorders. It was suggested that fibromyalgia patients have low resilience. This study aimed to assess the impact of resilience on disease severity and psychiatric comorbidities in patients with fibromyalgia.

Results

We found that patients with fibromyalgia had a significantly lower resilience and higher prevalence of psychiatric comorbidities than the control group (P < 0.05). Also, fibromyalgia patients with high disease severity had a significantly lower resilience and a higher percentage of psychiatric problems than those with a better disease state (P = 0.0001). Also, there was a significant negative correlation of resilience with disease severity (as assessed by the FIQ score), visual analog scale (VAS) of anxiety, and VAS of depression (P = 0.0001).

Conclusion

Resilience significantly impacts the severity and psychiatric comorbidities in patients with fibromyalgia. So, enhancing and improving resilience must be considered in the management protocols of fibromyalgia patients.

Non-invasive brain stimulation and pain neuroscience education in the cognitive-affective treatment of chronic low back pain: Evidence and future directions

Chronic low back pain (CLBP) is among the leading causes of disability worldwide. Beyond the physical and functional limitations, people's beliefs, cognitions, and perceptions of their pain can negatively influence their prognosis. Altered cognitive and affective behaviors, such as pain catastrophizing and kinesiophobia, are correlated with changes in the brain and share a dynamic and bidirectional relationship. Similarly, in the presence of persistent pain, attentional control mechanisms, which serve to organize relevant task information are impaired. These deficits demonstrate that pain may be a predominant focus of attentional resources, leaving limited reserve for other cognitively demanding tasks. Cognitive dysfunction may limit one's capacity to evaluate, interpret, and revise the maladaptive thoughts and behaviors associated with catastrophizing and fear. As such, interventions targeting the brain and resultant behaviors are compelling. Pain neuroscience education (PNE), a cognitive intervention used to reconceptualize a person's pain experiences, has been shown to reduce the effects of pain catastrophizing and kinesiophobia. However, cognitive deficits associated with chronic pain may impact the efficacy of such interventions. Non-invasive brain stimulation (NIBS), such as transcranial direct current stimulation (tDCS) or repetitive transcranial magnetic stimulation (rTMS) has been shown to be effective in the treatment of anxiety, depression, and pain. In addition, as with the treatment of most physical and psychological diagnoses, an active multimodal approach is considered to be optimal. Therefore, combining the neuromodulatory effects of NIBS with a cognitive intervention such as PNE could be promising. This review highlights the cognitive-affective deficits associated with CLBP while focusing on current evidence for cognition-based therapies and NIBS.

Electrophysiological indices of pain expectation abnormalities in fibromyalgia patients

Fibromyalgia is a chronic pain syndrome characterized by dysfunctional processing of nociceptive stimulation. Neuroimaging studies have pointed out that pain-related network functioning seems to be altered in these patients. It is thought that this clinical symptomatology may be maintained or even strengthened because of an enhanced expectancy for painful stimuli or its forthcoming appearance. However, neural electrophysiological correlates associated with such attentional mechanisms have been scarcely explored. In the current study, expectancy processes of upcoming laser stimulation (painful and non-painful) and its further processing were explored by event-related potentials (ERPs). Nineteen fibromyalgia patients and twenty healthy control volunteers took part in the experiment. Behavioral measures (reaction times and subjective pain perception) were also collected. We manipulated the pain/no pain expectancy through an S1–S2 paradigm (cue-target). S1 (image: triangle or square) predicted the S2 appearance (laser stimulation: warmth or pinprick sensation). Laser stimuli were delivered using a CO₂ laser device. Temporal and spatial principal component analyses were employed to define and quantify the ERP component reliability. Statistical analyses revealed the existence of an abnormal pattern of pain expectancy in patients with fibromyalgia. Specifically, our results showed attenuated amplitudes at posterior lCNV component in anticipation of painful stimulation that was not found in healthy participants. In contrast, although larger P2 amplitudes to painful compared to innocuous events were shown, patients did not show any amplitude change in this laser-evoked response as a function of pain predictive cues (as occurred in the healthy control group). Additionally, analyses of the subjective perception of pain and reaction time indicated that laser stimuli preceded by pain cues were rated as more painful than those signaling non-pain expectancy and were associated with faster responses. Differences between groups were not found. The present findings suggest the presence of dysfunction in pain expectation mechanisms in fibromyalgia that eventually may make it difficult for patients to correctly interpret signs that prevent pain symptoms. Furthermore, the abnormal pattern in pain expectancy displayed by fibromyalgia patients could result in ineffective pain coping strategies. Understanding the neural correlates of pain processing and its modulatory factors is crucial to identify treatments for chronic pain syndromes.

Inflammatory Bowel Disease and Pain Interference: A Conceptual Model for the Role of Insomnia, Fatigue, and Pain Catastrophizing

Background

People with inflammatory bowel disease (IBD) commonly experience pain influenced by complex interactions among factors, including disease activity, sleep, psychopathology, and changes in pain processing pathways. Treatments for pain in IBD are limited, highlighting the need for research that explores modifiable factors linked to pain. The aim of this study was to investigate relationships among multiple patient factors and to construct a conceptual model for pain interference in IBD.

Methods

A cross-sectional survey of adults with IBD. Study domains included demographic, comorbidity, psychological, IBD, insomnia, fatigue, and pain features. Structural equation modeling (SEM) was used to examine relationships and interactions among active IBD, insomnia, fatigue, pain experiences (severity, catastrophizing, and interference), and additional patient factors (demographics and psychological).

Results

One hundred and seventy-four participants, aged 18-85 years, reported the presence of pain. Combining the questionnaire data using SEM resulted in a final model with an excellent fit (χ ²(8) = 9.579, P = .297, χ ²/N = 1.197, CFIN = 0.997, TLI = 0.987, RMSEA = 0.034). The presence of anxiety and depression was the additional patient factors to be retained in the path analysis. SEM results indicated that greater pain interference was directly influenced by greater fatigue, worse pain catastrophizing, and worse pain severity. Pain interference was indirectly impacted by IBD activity, worse insomnia, and the presence of depression and anxiety.

Conclusions

The proposed conceptual model highlights the role of multiple potentially modifiable factors, including insomnia, pain catastrophizing, and fatigue, contributing to worse pain interference in people with IBD.

The Mediating Role of Depression and Pain Catastrophizing in the Relationship between Functional Capacity and Pain Intensity in Patients with Fibromyalgia

Background

Fibromyalgia syndrome (FMS) is a chronic musculoskeletal pain condition characterized by widespread pain, sleep problems (i.e., insomnia and unrefreshing sleep), fatigue, cognitive, and emotional difficulties. Although pain has been proposed the factor mostly impacting in the FMS patients' function, emotional and psychological FMS-associated factors are also known to exert a negative impact in quality of life and functional capacity. Nonetheless, the relationship between these factors and functional limitations in FMS patients is considered to be complex and not clearly defined. Therefore, the present study is aimed at assessing the associations between FMS functional capacity, FMS symptoms (pain, fatigue, insomnia, depression, and state and trait anxiety), and associated psychological factors such as pain catastrophizing, as well as the possible mediating role of these latter in the relationship between pain and FMS functional capacity.

Method

115 women diagnoses with FMS completed a set of self-administered questionnaires to evaluate the clinical and psychological variables of the study.

Results

FMS functional capacity was positively associated with the majority of FMS symptoms except state anxiety. Regression analyses confirmed a greater prediction for FMS functional capacity by depression, fatigue, and pain catastrophizing, in this sequence. Both, pain catastrophizing and depression were important factors mediating the association between clinical pain (total and intensity) and FMS functional capacity.

Conclusions

Findings support a key role of pain catastrophizing and depression in the disability associated to pain in FMS. Treatment goals directed to lessen depression and pain catastrophizing levels should be promoted to reduce the impact of pain in FMS patients' daily function.

Nociplastic pain concept, a mechanistic basis for pragmatic approach to fibromyalgia

Nociplastic pain (NP), as a mechanistic term, denotes pain arising from altered nociception without clear evidence of tissue or somatosensory damage. Fibromyalgia (FM), a prototypical NP condition, incorporates a broad continuum of phenotypes with a distinct neurobiological signature and shared NP attributes. The nociplastic concept may provide a new opportunity for early diagnosis of FM by identifying the characteristic NP features before a state of pain generalization and symptoms clustering. In this approach, even individual symptoms associated with NP features are worthy of attention to denote FM. It may provide a timely diagnosis of FM before clinical progression to a severe and hard-to-manage condition. Furthermore, collecting all various FM phenotypes under the nociplastic concept and not delimiting FM to the only typical presentation allows investigators to identify FM subgroups reflecting potentially distinct pathophysiologic mechanisms and biomarkers. This viewpoint can be served in future studies to develop individualized management. In this review, we postulate a novel approach to early FM diagnosis and management based on NP conceptualization and phenotype recognition. Key Points • FM as a NP condition represents overlapping clinical phenotypes and incomplete presentations especially in early stage of illness. • The mechanistic approach based on the NP features of FM can be implicated in the timely diagnosis and management of FM. • The NP-based approach to FM provides a broader viewpoint beyond FM delimitation to pain generalization and polysymptomatic complaints.

The interaction between pain and cognition: on the roles of task complexity and pain intensity

OBJECTIVES

The interaction between pain and cognition includes a concurrent negative effect of pain on cognitive performance and an analgesic effect of cognitive distraction on pain experience. The purpose of this exploratory study was to investigate the role of pain intensity and task complexity on this interaction.

METHODS

Two experiments were conducted in healthy volunteers. In both experiments, participants completed 3 conditions: a pain only condition (consisting of the cold pressor test), a cognition only condition (consisting of the cognitive task) and a combined condition (concurrent administration of the cold pressor and cognitive task). In experiment I, participants performed one out of three possible tasks that differed in cognitive load (low, medium, high). In experiment II the parameters of the pain stimulus, induced by a cold pressor test, were adapted and only the high load cognitive task was employed. Pain scores, reaction times, and accuracy rates were recorded.

RESULTS

In experiment I, cognitive distraction significantly decreased pain scores, irrespective of the cognitive load of the task. Pain did not affect cognitive performance. In experiment II, pain diminished accuracy rates. No effect of cognitive distraction on pain was observed. Individual characteristics did not noticeably influence the interaction between pain and cognition.

CONCLUSIONS

The results of this study suggest a two-way interaction, however no evidence for a simultaneous bidirectional relationship was found. Cognitive distraction successfully reduces pain, up until a certain point where this relationship is reversed, and pain starts to interfere with cognitive performance. This may imply that priorities shift at a certain pain-threshold, however further research should confirm this hypothesis. This study could contribute to further understanding of cognitive mechanisms related to pain perception.

Whole Body Pain Distribution and Risk Factors for Widespread Pain Among Patients Presenting with Abdominal Pain: A Retrospective Cohort Study

Introduction

Abdominal pain frequently co-occurs with pain in other body sites. Chronic overlapping pain conditions (COPCs) represent a group of widespread pain diagnoses. Our study characterized how patterns of somatic pain distribution are associated with COPCs and aimed to characterize predictors of widespread pain among patients with chronic abdominal pain.

Methods

This retrospective cohort study included adults presenting to a tertiary pain clinic, reporting abdominal pain at their initial visit, and with a follow-up visit at 12 months. Body maps divided patients into localized, intermediate, and widespread pain distribution patterns. Diagnostic and psychosocial measures were assessed across groups at the initial and follow-up visits. We analyzed the association of baseline diagnoses and demographics and time-varying changes in psychosocial measures from initial to follow-up visit with changes in pain distribution over time with alternating logistic regression (ALR).

Results

Among 258 patients, most were female (91.5%) and reported widespread pain (61.5%). Those with widespread pain at baseline reported elevated anger and 60.0% of patients remained in the same pain category at follow-up. Multivariable ALR demonstrated higher pain interference (AOR 1.06, 95% CI 1.02–1.10, P = 0.002), higher anxiety (AOR 1.05, 95% CI 1.01–1.09, P = 0.01), more than one COPC at initial visit (AOR 2.85, 95% CI 1.59–5.11, P = 0.0005), and initial visit widespread pain categorization (AOR 4.18, 95% CI 2.20–8.00, P < 0.0001) were associated with an increased risk of widespread pain at the follow-up visit.

Conclusion

Most patients with abdominal pain report additional pain locations at multiple other body sites, and non-localized pain persists 12 months after pain treatment. Screening for widespread pain and COPC at the initial visit may identify patients at higher risk for persistent or new-onset widespread pain, and interventions to reduce pain interference and anxiety may promote reversal of widespread pain.

Associations between pain catastrophizing and resting-state functional brain connectivity: Ethnic/race group differences in persons with chronic knee pain

Chronic pain is a significant public health problem, and the prevalence and societal impact continues to worsen annually. Multiple cognitive and emotional factors are known to modulate pain, including pain catastrophizing, which contributes to pain facilitation and is associated with altered resting-state functional connectivity in pain-related cortical and subcortical circuitry. Pain and catastrophizing levels are reported to be higher in non-Hispanic black (NHB) compared with non-Hispanic White (NHW) individuals. The current study, a substudy of a larger ongoing observational cohort investigation, investigated the pathways by which ethnicity/race influences the relationship between pain catastrophizing, clinical pain, and resting-state functional connectivity between anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (dlPFC), insula, and primary somatosensory cortex (S1). Participants included 136 (66 NHBs and 70 NHWs) community-dwelling adults with knee osteoarthritis. Participants completed the Coping Strategies Questionnaire-Revised Pain Catastrophizing subscale and Western Ontario and McMaster Universities Osteoarthritis Index. Magnetic resonance imaging data were obtained, and resting-state functional connectivity was analyzed. Relative to NHW, the NHB participants were younger, reported lower income, were less likely to be married, and self-reported greater clinical pain and pain catastrophizing (ps < 0.05). Ethnicity/race moderated the mediation effects of catastrophizing on the relationship between clinical pain and resting-state functional connectivity between the ACC, dlPFC, insula, and S1. These results indicate the NHB and NHW groups demonstrated different relationships between pain, catastrophizing, and functional connectivity. These results provide evidence for a potentially important role of ethnicity/race in the interrelationships among pain, catastrophizing, and resting-state functional connectivity.

The puzzle of fibromyalgia between central sensitization syndrome and small fiber neuropathy: a narrative review on neurophysiological and morphological evidence

Fibromyalgia (FM) is a condition characterized by chronic widespread pain whose pathogenesis is still not fully defined. Evidence based on structural and functional neuroimaging methods, electrophysiological, and morphological - skin biopsy - features demonstrated a central and peripheral nervous system involvement. A dysfunction in nociceptive inputs processing at the central level was highlighted as the primary cause of FM, but other data coming from different laboratories contributed to emphasize again the peripheral origin of FM. In fact, small fibers neuropathy (SFN) was observed in a large number of patients submitted to skin biopsy. The complex interaction between central and peripheral factors is opening a new scenario about the management of this neurological disorder. Whether proximal SFN is an initiating event leading to FM or is the consequence of stress-related insular hyper excitability remains unclear. Mild sufferance of peripheral afferents could function as a trigger for an exaggerated response of the so-called "salience matrix" in predisposed individuals. On the other side, the intriguing hypothesis rising from animal models could indicate that the cortical hyper function could cause peripheral small afferent damage. The research should go on the genetic origin of such peripheral and central abnormalities, the acquired facilitating factors, and the presence of different phenotypes in order to search for efficacious treatments, which are still lacking.

Distinct aberrations in cerebral pain processing differentiating patients with fibromyalgia from patients with rheumatoid arthritis

ABSTRACT

The current study used functional magnetic resonance imaging to directly compare disease-relevant cerebral pain processing in well-characterized patient cohorts of fibromyalgia (FM, nociplastic pain) and rheumatoid arthritis (RA, nociceptive pain). Secondary aims were to identify pain-related cerebral alterations related to the severity of clinical symptoms such as pain intensity, depression, and anxiety. Twenty-six patients with FM (without RA-comorbidity) and 31 patients with RA (without FM-comorbidity) underwent functional magnetic resonance imaging while stimulated with subjectively calibrated painful pressures corresponding to a pain sensation of 50 mm on a 100-mm visual analogue scale. Stimulation sites were at the most inflamed proximal interphalangeal joint in the left hand in patients with RA and the left thumbnail in patients with FM, 2 sites that have previously been shown to yield the same brain activation in healthy controls. The current results revealed disease-distinct differences during pain modulation in RA and FM. Specifically, in response to painful stimulation, patients with FM compared to patients with RA exhibited increased brain activation in bilateral inferior parietal lobe (IPL), left inferior frontal gyrus (IFG)/ventrolateral prefrontal cortex (vlPFC) encapsulating left dorsolateral prefrontal cortex, and right IFG/vlPFC. However, patients with RA compared to patients with FM exhibited increased functional connectivity (during painful stimulation) between right and left IPL and sensorimotor network and between left IPL and frontoparietal network. Within the FM group only, anxiety scores positively correlated with pain-related brain activation in left dorsolateral prefrontal cortex and right IFG/vlPFC, which further highlights the complex interaction between affective (ie, anxiety scores) and sensory (ie, cerebral pain processing) dimensions in this patient group.

Central pain modulatory mechanisms of attentional analgesia are preserved in fibromyalgia

ABSTRACT

Fibromyalgia is a prevalent pain condition that is associated with cognitive impairments including in attention, memory, and executive processing. It has been proposed that fibromyalgia may be caused by altered central pain processing characterised by a loss of endogenous pain modulation. We tested whether attentional analgesia, where cognitive engagement diminishes pain percept, was attenuated in patients with fibromyalgia (n = 20) compared with matched healthy controls (n = 20). An individually calibrated, attentional analgesia paradigm with a 2 × 2 factorial design was used with brain and brainstem-focussed functional magnetic resonance imaging. Patients with fibromyalgia had both lower heat pain thresholds and speeds in a visual attention task. When this was taken into account for both attentional task and thermal stimulation, both groups exhibited an equivalent degree of attentional analgesia. Functional magnetic resonance imaging analysis showed similar patterns of activation in the main effects of pain and attention in the brain and brainstem (with the sole exceptions of increased activation in the control group in the frontopolar cortex and the ipsilateral locus coeruleus). The attentional analgesic effect correlated with activity in the periaqueductal gray and rostral ventromedial medulla. These findings indicate that patients with fibromyalgia can engage the descending pain modulatory system if the attentional task and noxious stimulus intensity are appropriately titrated.

Impact of bifrontal home-based transcranial direct current stimulation in pain catastrophizing and disability due to pain in fibromyalgia: a randomized, double-blind sham-controlled study

This randomized, double-blind trial tested the hypothesis that twenty sessions of home-based anodal(a)-transcranial direct current stimulation (tDCS) (2mA for 20 min) bifrontal, with anodal on the left dorsolateral prefrontal cortex (l-DLPFC) would be better than sham-(s)-tDCS to reduce scores on Pain Catastrophizing Scale (PCS) and disability-related to pain (DRP) assessed by the Profile of Chronic Pain: Screen (PCP:S) (primary outcomes). Secondary outcomes were depressive symptoms, sleep quality, heat pain threshold (HPT), heat pain tolerance (HPTo), and serum brain-derived-neurotrophic-factor (BDNF). Forty-eight women with fibromyalgia, 30-65 years-old were randomized into 2:1 groups [a-tDCS (n=32) or s-tDCS (n=16)]. Post hoc analysis revealed that a-tDCS reduced the PCS total scores by 51.38% compared to 26.96% in s-tDCS, and a-tDCS reduced PCP:S total scores by 31.43% compared to 19.15% in s-tDCS. The a-tDCS improved depressive symptoms, sleep quality and increased the HPTo. The delta-value in the serum BDNF (mean post treatment end minus pre-treatment) was conversely correlated with the a-tDCS effect in pain catastrophizing. In contrast, the a-tDCS impact on reducing the DRP at the treatment end was positively associated with a reduction in the serum BDNF and improvement of depressive symptoms, sleep quality and pain catastrophizing symptoms. PERSPECTIVE: Home-based bifrontal tDCS with a-tDCS on the l-DLPFC are associated with a moderate effect size (ES) in the following outcomes: (i) Decreased rumination and magnification of pain catastrophizing. (ii) Improved the disability for daily activities due to fibromyalgia symptoms. Overall, these findings support the feasibility of self-applied home-based tDCS on DLPFC to improve fibromyalgia symptoms.

Diagnostic Challenges and Management of Fibromyalgia

The World Health Organization regards chronic pain to be a public health concern. In clinical medicine, fibromyalgia (FM) is the most prevalent chronic widespread pain disease. In terms of impairment, consumption of health and social resources, and impact on primary and speciality care systems, it has reached worrisome proportions. This disease is frequently managed by primary care providers. Because of its intricacy, fibromyalgia diagnosis and treatment can be difficult. Fibromyalgia is a controversial condition. It might appear ill-defined in comparison to other pain conditions, with no clear knowledge of pathophysiology and hence no particular targeted therapy. This invariably sparks debates and challenges. There is no obvious cut-off point that distinguishes FM from non-FM. The diagnosis of fibromyalgia has been complicated by several factors, including patients' health-seeking behaviour, symptom identification, and physician labelling of the disease. Fibromyalgia is currently considered a centralized pain condition, according to research that has improved our understanding of its etiopathology. A multidisciplinary strategy combining pharmacological and non-pharmacological therapies based on a biopsychosocial paradigm can result in effective therapy. Cultural and psychosocial variables appear to be a recent development in fibromyalgia, and they appear to have a larger influence on physician diagnosis than severe symptom levels in FM patients. Although physicians rely on FM criteria as the only way to classify FM patients in research and clinical settings, some crucial elements of the diagnostic challenge of fibromyalgia remain unsolved - invalidation, psychosocial variables, and diverse illness manifestation are some examples. Beyond the existing constructional scores, physicians' judgment gained in real communicative contexts with patients, appears to be the only dependable route for a more accurate diagnosis for fibromyalgia. We have performed an exhaustive review of the literature using the keywords "Fibromyalgia", "challenges" and "diagnosis" in PubMed and Google Scholar indexes up to September 2021. This article aims to examine the causes, diagnosis, and current treatment protocols of FM, as well as discuss some continuing debates and diagnostic challenges which physicians face in accurately diagnosing fibromyalgia.

Fibromyalgia and Associated Disorders: From Pain to Chronic Suffering, From Subjective Hypersensitivity to Hypersensitivity Syndrome

The concept of fibromyalgia has progressed to achieve a certain consensus regarding the definition of the condition. We summarize what is known in 2020, be it in terms of diagnosis, with the criteria that have changed over the years, or at the level of the psychological profile, via the notions of "catastrophizing" and "coping" and post-traumatic syndrome. The importance of fatigue and sleep disorders is underlined, with the chronological sequence of post-traumatic syndrome, chronic fatigue, and then amplification of the pain and the onset of multiple associated symptoms. The etiopathogenic debate has been enriched thanks to neuro-imaging data to discover the start of the central neurological signature. The many associated symptoms are reanalyzed in the context of so-called sister conditions which form sometimes more or less separate entities, such as chronic fatigue syndrome or restless legs syndrome for example. What these conditions have in common is hypersensitivity, not just to pain, but also to all exteroceptive stimuli, from deep sensitivity in the neuro-vegetative system, the sense organs and certain functions of the central nervous system, to the psychological aspects and sleep control. In summary, it is possible to define fibromyalgia as a cognitive disorder of cortical integration of chronic pain, with amplification of painful and sensory nociception, decrease in the threshold for the perception of pain, and persistence of a stimulus that maintains the process in chronicity. Fibromyalgia is part of a group of chronic hypersensitivity syndromes of central origin, with a very wide range of means of expression.

Contextualizing goal preferences in fear-avoidance models. Looking at fatigue as a disabling symptom in fibromyalgia patients

The fear-avoidance model provides an explanation for the development of chronic pain, including the role of perception (i.e. pain catastrophism) as an explanatory variable. Recent research has shown that the relationship between pain catastrophism and avoidance is influenced in turn by different psychological and contextual variables, highlighting the affective-motivational ones. From this perspective, the Goal Pursuit Questionnaire (GPQ) was developed to measure the preference for hedonic goals (mood-management or pain-avoidance goals) over achievement goals in musculoskeletal pain patients. Recently, the Spanish version of the GPQ in fibromyalgia patients has been validated. Our aim has been to adapt the Spanish version of GPQ from pain to fatigue symptoms and to validate this new questionnaire (GPQ-F) in fibromyalgia. Despite the recognition of fibromyalgia as a complex disorder and the need for a differential study of its symptoms, fatigue, despite its high prevalence and limiting nature, remains the forgotten symptom. We conducted a cross-sectional study with 231 women with fibromyalgia. Previously, we adapted the Spanish GPQ for fatigue symptoms with three sub-studies (group structured interview, self-administration questionnaire and thinking-aloud; n = 15–27 patients). We explored the GPQ structure and performed path analyses to test conditional mediation relationships. Exploratory factor analysis showed two factors: ‘Fatigue-avoidance goal’ and ‘Mood-management goal’ (39.3% and 13.9% of explained variance, respectively). The activity avoidance pattern fully mediated the relation between both catastrophizing and fatigue-avoidance goals with fatigue. The study shows initial findings about the usefulness of the GPQ-F as a tool to analyze goal preferences related to fatigue in fibromyalgia. The results supported the mediational role of activity avoidance patterns in the relationship between preference for fatigue-avoidance goals and fatigue.

Changes in prefrontal cortex activation with exercise in knee osteoarthritis patients with chronic pain: An fNIRS study

The role of exercise on pain modulatory mechanism of the prefrontal areas is not clear. We aimed to determine the effects of exercise on functional activity of the prefrontal cortex in patients with knee osteoarthritis (OA) with chronic pain and to assess the relationships between changes in clinical variables and cortical hemodynamics with exercise via functional near-infrared spectroscopy (fNIRS). Fifteen patients with knee OA with chronic pain were included. All participants attended an exercise program 3 times a week for 6 weeks. Pain during activity was assessed by visual analogue scale (VAS). Pain catastrophization, kinesiophobia and functionality were also measured. Brain hemodynamic activity was assessed with a 47-channel fNIRS system before and after the exercise. Pain, pain catastrophization, kinesiophobia and functionality scores significantly improved (p < 0.05) while functional activity of the dorsolateral prefrontal cortex (DLPFC) during painful stimuli was significantly reduced after exercise program (p < 0.05). Change in cortical hemodynamic activity within the DLPFC was significantly correlated with change in pain perception (R = 0.54, p < 0.05) and pain catastrophization scores (R = 0.44, p < 0.05). Exercise resulted in improvements in clinical assessments of pain severity and pain catastrophization which was accompanied by alterations in prefrontal cortex activation. We provided evidence about the pain modulatory effects of exercise at cortical level which is correlated with clinical improvements in patients with chronic pain. We demonstrate the feasibility and potential of fNIRS methodology for i) elucidating the neural mechanisms underlying chronic and stimulus evoked pain, and ii) exploring the effect of treatment methods on brain functionality.

Nociceptive stress interferes with neural processing of cognitive stimuli in Gulf War Veterans with chronic musculoskeletal pain

AIMS

Disrupted cognition and chronic musculoskeletal pain (CMP) are prevalent experiences among Gulf War Veterans (GWV). A negative association between CMP and cognition (i.e., chronic pain-related cognitive interference) has been observed in some chronic pain populations but has not been evaluated in GWV. Additional research suggests that disrupted cognition in GWV with CMP may be exacerbated by stressing the nociceptive system. Therefore, we compared cognitive performance and related neural activity between CMP and healthy control (CO) GWV in the absence and presence of experimental pain.

MAIN METHODS

During functional magnetic resonance imaging (fMRI), Veterans (CMP = 29; CO = 27) completed cognitive testing via congruent and incongruent conditions of a modified Stroop task (Stroop-only). A random subset (CMP = 13; CO = 13) also completed cognitive testing with experimental pain (Pain+Stroop). Yuen's modified t-test and robust mixed-model analysis of variance (ANOVA) models were used for analyzing cognitive performance data. Independent t-tests and repeated-measures ANOVA models were employed for fMRI data with thresholding for multiple-comparisons (p < 0.005) and cluster size (> 320 mm³).

KEY FINDINGS

Functional MRI analysis revealed significant between-group differences for the incongruent but not congruent-Stroop run. Neither correct responses nor reaction time differed between groups in either Stroop condition (all p ≥ 0.21). Significant group (CMP, CO) by run (Stroop-only, Pain+Stroop) interactions revealed greater neural responses in CMP Veterans during Pain+Stroop runs. No significant interactions were observed for correct responses or reaction time (p ≥ 0.31).

SIGNIFICANCE

GWV with CMP require a greater amount of neural resources to sustain cognitive performance during nociceptive stress.

Clustering fibromyalgia patients: A combination of psychosocial and somatic factors leads to resilient coping in a subgroup of fibromyalgia patients

Background

Coping strategies and their efficacy vary greatly in patients suffering from fibromyalgia syndrome (FMS).

Objective

We aimed to identify somatic and psychosocial factors that might contribute to different coping strategies and resilience levels in FMS.

Subjects and methods

Standardized questionnaires were used to assess coping, pain, and psychological variables in a cohort of 156 FMS patients. Quantitative real-time polymerase chain reaction (qRT-PCR) determined gene expression of selected cytokines in white blood cells of 136 FMS patients and 25 healthy controls. Data of skin innervation, functional and structural sensory profiles of peripheral nociceptive nerve fibers of a previous study were included into the statistics. An exploratory factor analysis was used to define variance explaining factors, which were then included into cluster analysis.

Results

54.9% of the variance was explained by four factors which we termed (1) affective load, (2) coping, (3) pain, and (4) pro-inflammatory cytokines (p < 0.05). Considering differences in the emerged factors, coping strategies, cytokine profiles, and disability levels, 118 FMS patients could be categorized into four clusters which we named “maladaptive”, “adaptive”, “vulnerable”, and “resilient” (p < 0.05). The adaptive cluster had low scores in disability and in all symptom categories in contrast to the vulnerable cluster, which was characterized by high scores in catastrophizing and disability (p < 0.05). The resilient vs. the maladaptive cluster was characterized by better coping and a less pro-inflammatory cytokine pattern (p < 0.05).

Conclusion

Our data suggest that problem- and emotion-focused coping strategies and an anti-inflammatory cytokine pattern are associated with reduced disability and might promote resilience. Additional personal factors such as low anxiety scores, ability of acceptance, and persistence further favor a resilient phenotype. Individualized therapy should take these factors into account.

Pain Catastrophizing Is Related to Static Postural Control Impairment in Patients with Nonspecific Chronic Low Back Pain: A Cross-Sectional Study

Purpose

Pain catastrophizing may contribute to the altered trunk muscle activity in patients with nonspecific chronic low back pain (NSCLBP). It is unclear if pain catastrophizing influences static postural control in patients with NSCLBP. This study aimed to investigate the relationship between pain catastrophizing and static postural control in NSCLBP patients.

Methods

Sixty-eight participants with NSCLBP and 40 healthy participants were recruited. Postural control was assessed by the sway area and the sway length of the center of pressure (COP) during balance tests. Pain catastrophizing in participants with NSCLBP was assessed by the Pain Catastrophizing Scale (PCS). Bilateral transversus abdominis (TrA) activation was evaluated by ultrasound imaging-measured percent change in muscle thickness. Associations between COP parameter and PCS/subscales of PCS were examined by multiple linear regression (MLR).

Results

Our results observed a larger COP sway area in NSCLBP group under eyes-closed condition (p < 0.001) and a lower level of voluntary activation of the bilateral TrA (p < 0.001), compared with the healthy control group. The MLR analyses revealed that the COP area sway under eyes-closed condition was significantly associated with the PCS score/helplessness score of PCS, voluntary activation of the left TrA, and age in participants with NSCLBP (β = 0.222/0.236, 0.341/0.344, and 0.328/0.325; p=0.045/0.033, 0.002, and 0.004, resp.).

Conclusions

Static postural control was associated with pain catastrophizing, voluntary activation of TrA, and age in participants with NSCLBP. This indicated that pain catastrophizing may affect postural control and should be considered when interpreting balance test results and managing NSCLBP.

Pain Catastrophizing in Older Adults with Chronic Pain: The Mediator Effect of Mood Using a Path Analysis Approach

Cognitive models of pain propose that catastrophic thinking is negatively associated with chronic pain. However, pain catastrophizing is a complex phenomenon requiring a multivariate examination. This study estimates the effects of mood variables (anxiety and depression) on pain catastrophizing in older adults with chronic pain. A postal survey addressing pain aspects was sent to 6611 people ≥ 65 years old living in south-eastern Sweden. Pain catastrophizing was measured using the pain catastrophizing scale. Anxiety and depression were assessed using two subscales of the general well-being schedule. Data were analysed using a path analysis approach. A total of 2790 respondents (76.2 ± 7.4 years old) reported chronic pain (≥three months). The mediation model accounted for 16.3% of anxiety, 17.1% of depression, and 30.9% of pain catastrophizing variances. Pain intensity, insomnia, number of comorbidities, and lifestyle factors (smoking, alcohol consumption, and weight) significantly affected both pain catastrophizing and mood. Anxiety (standardized path coefficient (b_std) = 0.324, p < 0.001) in comparison to depression (b_std = 0.125, p < 0.001) had a greater effect on pain catastrophizing. Mood mediated the relationship between pain catastrophizing and pain-related factors accounting for lifestyle and sociodemographic factors.

Cellular Circuits in the Brain and Their Modulation in Acute and Chronic Pain

Chronic, pathological pain remains a global health problem and a challenge to basic and clinical sciences. A major obstacle to preventing, treating, or reverting chronic pain has been that the nature of neural circuits underlying the diverse components of the complex, multidimensional experience of pain is not well understood. Moreover, chronic pain involves diverse maladaptive plasticity processes, which have not been decoded mechanistically in terms of involvement of specific circuits and cause-effect relationships. This review aims to discuss recent advances in our understanding of circuit connectivity in the mammalian brain at the level of regional contributions and specific cell types in acute and chronic pain. A major focus is placed on functional dissection of sub-neocortical brain circuits using optogenetics, chemogenetics, and imaging technological tools in rodent models with a view towards decoding sensory, affective, and motivational-cognitive dimensions of pain. The review summarizes recent breakthroughs and insights on structure-function properties in nociceptive circuits and higher order sub-neocortical modulatory circuits involved in aversion, learning, reward, and mood and their modulation by endogenous GABAergic inhibition, noradrenergic, cholinergic, dopaminergic, serotonergic, and peptidergic pathways. The knowledge of neural circuits and their dynamic regulation via functional and structural plasticity will be beneficial towards designing and improving targeted therapies.

Aberrant Salience? Brain Hyperactivation in Response to Pain Onset and Offset in Fibromyalgia

OBJECTIVE

While much brain research on fibromyalgia (FM) focuses on the study of hyperresponsiveness to painful stimuli, some studies suggest that the increased pain-related brain activity often reported in FM studies may be partially explained by stronger responses to salient aspects of the stimulation rather than, or in addition to, the stimulation's painfulness. Therefore, this study was undertaken to test our hypothesis that FM patients would demonstrate elevated brain responses to both pain onset and offset-2 salient sensory events of opposing valences.

METHODS

Thirty-eight FM patients (mean ± SD age 46.1 ± 13.4 years; 33 women) and 15 healthy controls (mean ± SD age 45.5 ± 12.4; 10 women) received a moderately painful pressure stimulus to the leg during blood oxygen level-dependent (BOLD) functional magnetic resonance imaging. Stimulus onset and offset transients were analyzed using a general linear model as stick functions.

RESULTS

During pain onset, higher BOLD signal response was observed in FM patients compared to healthy controls in dorsolateral and ventrolateral prefrontal cortices (DLPFC and VLPFC, respectively), orbitofrontal cortex (OFC), frontal pole, and precentral gyrus (PrCG). During pain offset, higher and more widespread BOLD signal response was demonstrated in FM patients compared to controls in frontal regions significantly hyperactivated in response to onset. In FM patients, some of these responses were positively correlated with pain unpleasantness ratings (VLPFC, onset; r = 0.35, P = 0.03), pain catastrophizing scores (DLPFC, offset; r = 0.33, P = 0.04), or negatively correlated with stimulus intensity (OFC, offset; r = -0.35, P = 0.03) (PrCG, offset; r = -0.39, P = 0.02).

CONCLUSION

Our results suggest that the increased sensitivity exhibited by FM patients in response to the onset and offset of painful stimuli may reflect a more generalized hypersensitivity to salient sensory events, and that brain hyperactivation may be a mechanism potentially involved in the generalized hypervigilance to salient stimuli in FM.

Acupuncture for Fibromyalgia: An Open-Label Pragmatic Study on Effects on Disease Severity, Neuropathic Pain Features, and Pain Catastrophizing

The treatment of fibromyalgia syndrome (FMS) is still far from being optimally coded, and pharmacological strategies are often unsatisfactory. Acupuncture plays a role among nonpharmacological intervention approaches; however, there is still no clarity as to when to integrate it into therapy. The objective of this study is to explore the role of acupuncture, in terms of efficacy on main disease severity measures and pain features, in patients with nonresponsive disease, defining nonresponsive FMS characterized by a revised Fibromyalgia Impact Questionnaire (FIQ-R) ≥39 and a Patient Health Questionnaire 15-item (PHQ15) ≥5 despite optimal drug therapy. Patients were treated with weekly sessions, for a total of eight acupuncture sessions. At the baseline and at the end of the treatment cycle, a comprehensive clinical evaluation was carried out to evaluate improvements in terms of disease severity and impact on neuropathic pain features (measured with the painDETECT questionnaire (PDQ)) and pain catastrophizing (measured with the Pain Catastrophizing Scale (PCS)). At the end of the eight-week treatment, patients experienced a significant improvement in all evaluated parameters (for FIQ-R, PDQ, and PHQ15 p < 0.0001, for PCS p=0.001). Of particular note is the effectiveness on manifestations that are difficult to treat such as neuropathic pain features and on negative psychological perceptions such as pain catastrophizing. It can be stated that acupuncture can be proposed also in phases of high severity of disease. Intervention with multimodal strategies, including acupuncture, could be of great benefit to patients.

Capturing Novel Non-opioid Pain Targets

The relatively high efficacy of opioids, which have associated risks of addiction, tolerance, and dependence, for the management of acute and terminal pain has been a major driver of the opioid crisis, together with the availability, overprescription, and diversion of these drugs. Eliminating opioids without an effective replacement is, however, no solution, as it substitutes one major problem with another. To deal successfully with the opioid crisis, we need to discover novel analgesics whose mechanisms do not involve the mu opioid receptor but that have high analgesic potency and low risk of adverse effects, particularly no abuse liability. The question is how to achieve this. There are several necessary elements; first, we need to understand the nature of pain and the mechanisms responsible for it, and second, we need to adopt novel and unbiased approaches to the identification and validation of pain targets.

Emotional intelligence impairments in women with fibromyalgia: Associations with widespread pain

This study aimed at testing the differences in emotional intelligence ability between women with fibromyalgia (cases) and their age-matched counterparts not with fibromyalgia from the general population (controls) and analysing the association between emotional intelligence ability and widespread pain in women with fibromyalgia. A total of 133 cases and 77 controls participated in this cross-sectional study. Controls performed better than cases on emotion understanding. Higher emotion perception and management were significantly associated with lower widespread pain. Therefore, women with fibromyalgia may experience difficulties in understanding emotional information. In fibromyalgia, higher emotion perception and management abilities are independently related to lower widespread pain.