Differential psychophysiological effects of operant and cognitive behavioural treatments in women with fibromyalgia

Neural indices of multimodal sensory and autonomic hyperexcitability in fibromyalgia

Fibromyalgia (FM) is characterized by chronic widespread musculoskeletal pain and psychological distress. Research suggests people with FM experience increased somatosensory sensitization which generalizes to other sensory modalities and may indicate neural hyperexcitability. However, the available evidence is limited, and studies including measures of neural responsivity across sensory domains and both central and peripheral aspects of the neuraxis are lacking. Thirty-nine participants (51.5 ± 13.6 years of age) with no history of neurological disorders, psychosis, visual, auditory, or learning deficits, were recruited for this study. People with FM (N = 19) and control participants (CNT, N = 20) did not differ on demographic variables and cognitive capacity. Participants completed a task that combined innocuous auditory stimuli with electrocutaneous stimulation (ECS), delivered at individually-selected levels that were uncomfortable but not painful. Event-related potentials (ERPs) and electrodermal activity were analyzed to examine the central and sympathetic indices of neural responsivity. FM participants reported greater sensitivity to ECS and auditory stimulation, as well as higher levels of depression, anxiety, ADHD, and an array of pain-related experiences than CNT. In response to ECS, the P50 deflection was greater in FM than CNT participants, reflecting early somatosensory hyperexcitability. The P50 amplitude was positively correlated with the FM profile factor obtained with a principal component analysis. The N100 to innocuous tones and sympathetic reactivity to ECS were greater in FM participants, except in the subgroup treated with gabapentinoids, which aligns with previous evidence of symptomatic improvement with GABA-mimetic medications. These results support the principal tenet of generalized neural hyperexcitability in FM and provide preliminary mechanistic insight into the impact of GABA-mimetic pharmacological therapy on ameliorating the neural excitation dominance.

"INTEGRO INTEGRated Psychotherapeutic InterventiOn" on the Management of Chronic Pain in Patients with Fibromyalgia: The Role of the Therapeutic Relationship

Fibromyalgia (FM) is a chronic disease characterized by a heterogeneous set of physical and psychological conditions. The chronic experience of disability felt by patients and the impact on quality of life (QoL) of the disease may worsen the cognitive reappraisal ability and contribute to maintaining an altered pain modulation mechanism. This paper presents the study protocol of an INTEGRated psychotherapeutic interventiOn on the management of chronic pain in patients with fibromyalgia (INTEGRO). The aim of the study is to investigate the efficacy of an integrated psychotherapeutic intervention focused on pain management on QoL and pain perception, in a pilot sample of 45 FM patients with idiopathic chronic pain. The contribution of perceived therapeutic relationship (alliance) and physiological attunement, in both the patient and therapist, will be considered as possible mediators of intervention efficacy. Attachment dimensions, traumatic experiences, difficulties in emotion regulation, mindfulness attitude and psychophysiological profile will also be considered as covariates. The objectives are to evaluate longitudinally if patients will experience an increase in QoL perception (primary endpoint), pain-managing self-efficacy and emotion-regulation abilities as well as a reduction in pain intensity (secondary endpoints), considering the mediating role of perceived therapeutic alliance and physiological attunement in both the patient and therapist.

The PerPAIN trial: a pilot randomized controlled trial of personalized treatment allocation for chronic musculoskeletal pain-a protocol

BACKGROUND

The therapy of chronic musculoskeletal pain (CMSP) is complex and the treatment results are often insufficient despite numerous therapeutic options. While individual patients respond very well to specific interventions, other patients show no improvement. Personalized treatment assignment offers a promising approach to improve response rates; however, there are no validated cross-disease allocation algorithms available for the treatment of chronic pain in validated personalized pain interventions. This trial aims to test the feasibility and safety of a personalized pain psychotherapy allocation with three different treatment modules and estimate initial signals of efficacy and utility of such an approach compared to non-personalized allocation.

METHODS

This is a randomized, controlled assessor-blinded pilot trial with a multifactorial parallel arm design. CMSP patients (n = 105) will be randomly assigned 1:1 to personalized or non-personalized treatment based on a cluster assignment of the West Haven-Yale Multidimensional Pain Inventory (MPI). In the personalized assignment condition, patients with high levels of distress receive an emotional distress-tailored intervention, patients with pain-related interference receive an exposure/extinction-tailored treatment intervention and patients who adapt relatively well to the pain receive a low-level smartphone-based activity diary intervention. In the control arm, patients receive one of the two non-matching interventions. Effect sizes will be calculated for change in core pain outcome domains (pain intensity, physical and emotional functioning, stress experience, participant ratings of improvement and satisfaction) after intervention and at follow-up. Feasibility and safety outcomes will assess rates of recruitment, retention, adherence and adverse events. Additional data on neurobiological and psychological characteristics of the patients are collected to improve treatment allocation in future studies.

CONCLUSION

Although the call for personalized treatment approaches is widely discussed, randomized controlled trials are lacking. As the personalization of treatment approaches is challenging, both allocation and intervention need to be dynamically coordinated. This study will test the feasibility and safety of a novel study design in order to provide a methodological framework for future multicentre RCTs for personalized pain psychotherapy.

TRIAL REGISTRATION

German Clinical Trials Register, DRKS00022792 ( https://www.drks.de ). Prospectively registered on 04/06/2021.

A Systematic Review and Meta-Analysis of the Prevalence of Small Fibre Impairment in Patients with Fibromyalgia

Converging evidence shows that patients with fibromyalgia syndrome have signs of small fibre impairment, possibly leading to pain and autonomic symptoms, with a frequency that has not yet been systematically evaluated. To fill this gap, our review aims to define the frequency of somatic and autonomic small fibre damage in patients with fibromyalgia syndrome, as assessed by objective small fibre-related testing. We found 360 articles on somatic and autonomic small fibre assessment in patients with fibromyalgia. Out of the 88 articles assessed for eligibility, 20 were included in the meta-analysis, involving 903 patients with fibromyalgia. The estimated prevalence of somatic small fibre impairment, as assessed with skin biopsy, corneal confocal microscopy, and microneurography, was 49% (95% confidence interval (CI): 39–60%, I² = 89%), whereas the estimated prevalence of autonomic small fibre impairment, as assessed with heart rate variability, sympathetic skin response, skin conductance, and tilt testing, was 45% (95% CI: 25–65%, I² = 91%). Our study shows that a considerable proportion of patients with fibromyalgia have somatic and autonomic small fibre impairment, as assessed by extensive small fibre-related testing. Nevertheless, the heterogeneity and inconsistencies across studies challenge the exact role of small fibre impairment in fibromyalgia symptoms.

Short term relief of multisite chronicpain with Bowen Therapy: A double-blind, randomized controlled trial

INTRODUCTION

Bowen Therapy, a form of soft tissue manipulation, is commonly used to treat musculoskeletal conditions; yet, there is little evidence for its efficacy. The goal of the study was to investigate the impact of Bowen Therapy on pain and function in people with chronic pain in multiple locations. Additionally, we examined the mechanisms of effect through monitoring the nociceptive and autonomic nervous systems.

METHOD

The study was a double-blind, randomized controlled trial involving 31 people with chronic pain. Participants were randomized into real and sham therapy groups. Each group received 6 sessions of therapy over 8 weeks. The primary outcome measures of pain and function were assessed using standard questionnaires. Quantitative sensory testing was used to assess the nociceptive system, while recordings of heart rate variability and skin conductance were used to assess the autonomic nervous system. Outcome measures were assessed at baseline and at 1- and 6-weeks following completion of the intervention.

RESULTS

The real therapy group had a significantly lower pain score 1-week following the intervention compared to the sham group. There were no differences between groups at the final follow-up or in the function measures. There was no significant change in the nociceptive measures but there was evidence of increased activation of the sympathetic nervous system.

DISCUSSION

Bowen Therapy gave rise to a short-term reduction in pain that was not evident in a sham therapy group. The mechanisms of action of Bowen Therapy remain uncertain but may involve sympathoexcitation.

Reduced activity, reactivity and functionality of the sympathetic nervous system in fibromyalgia: An electrodermal study

Alterations in autonomic activity are well established in fibromyalgia syndrome (FMS). Previous studies found reduced parasympathetic activity and sympathetic reactivity to physical and stress manipulations. However, sympathetic activity at rest has not been well studied in FMS. Sweating is exclusively controlled by sympathetic mechanisms. In this study, skin conductance (SC), as an indirect measure of sweating, was analyzed in 45 women with FMS and 38 healthy women. Tonic SC levels were recorded during a 4-minute rest period, and a breathing maneuver consisting of deep breathing with posterior breath holding was used to evoke SC responses. Associations of tonic SC with state anxiety and body temperature, measured in the hand, were explored to determine sweat functionality. The results showed reduced tonic SC levels, with a less marked decrease in SC during the recording period, and blunted SC reactivity to the breathing manipulation in FMS patients relative to healthy participants. Positive associations of SC with state anxiety and body temperature were observed in healthy participants, but these associations were absent in FMS patients. These results indicate alterations of sweating in FMS, suggesting reduced tonic and reactivity sympathetic influences. Furthermore, the absence of associations between SC levels and state anxiety and body temperature in the patient sample suggested a loss of functionality of the autonomic nervous system in FMS. Diminished autonomic regulation in FMS would reduce the ability to cope with environmental demands, thus favoring increases in stress and pain levels. Finally, the observed reduction in sweating is in accordance with evidence of small nerve fiber neuropathy in FMS.

Psychological therapies for the management of chronic pain (excluding headache) in adults

BACKGROUND

Chronic non-cancer pain, a disabling and distressing condition, is common in adults. It is a global public health problem and economic burden on health and social care systems and on people with chronic pain. Psychological treatments aim to reduce pain, disability and distress. This review updates and extends its previous version, published in 2012.

OBJECTIVES

To determine the clinical efficacy and safety of psychological interventions for chronic pain in adults (age > 18 years) compared with active controls, or waiting list/treatment as usual (TAU).

SEARCH METHODS

We identified randomised controlled trials (RCTs) of psychological therapies by searching CENTRAL, MEDLINE, Embase and PsycINFO to 16 April 2020. We also examined reference lists and trial registries, and searched for studies citing retrieved trials.

SELECTION CRITERIA

RCTs of psychological treatments compared with active control or TAU of face-to-face therapies for adults with chronic pain. We excluded studies of headache or malignant disease, and those with fewer than 20 participants in any arm at treatment end.

DATA COLLECTION AND ANALYSIS

Two or more authors rated risk of bias, extracted data, and judged quality of evidence (GRADE). We compared cognitive behavioural therapy (CBT), behavioural therapy (BT), and acceptance and commitment therapy (ACT) with active control or TAU at treatment end, and at six month to 12 month follow-up. We did not analyse the few trials of other psychological treatments. We assessed treatment effectiveness for pain intensity, disability, and distress. We extracted data on adverse events (AEs) associated with treatment.

MAIN RESULTS

We added 41 studies (6255 participants) to 34 of the previous review's 42 studies, and now have 75 studies in total (9401 participants at treatment end). Most participants had fibromyalgia, chronic low back pain, rheumatoid arthritis, or mixed chronic pain. Most risk of bias domains were at high or unclear risk of bias, with selective reporting and treatment expectations mostly at unclear risk of bias. AEs were inadequately recorded and/or reported across studies. CBT The largest evidence base was for CBT (59 studies). CBT versus active control showed very small benefit at treatment end for pain (standardised mean difference (SMD) -0.09, 95% confidence interval (CI) -0.17 to -0.01; 3235 participants; 23 studies; moderate-quality evidence), disability (SMD -0.12, 95% CI -0.20 to -0.04; 2543 participants; 19 studies; moderate-quality evidence), and distress (SMD -0.09, 95% CI -0.18 to -0.00; 3297 participants; 24 studies; moderate-quality evidence). We found small benefits for CBT over TAU at treatment end for pain (SMD -0.22, 95% CI -0.33 to -0.10; 2572 participants; 29 studies; moderate-quality evidence), disability (SMD -0.32, 95% CI -0.45 to -0.19; 2524 participants; 28 studies; low-quality evidence), and distress (SMD -0.34, 95% CI -0.44 to -0.24; 2559 participants; 27 studies; moderate-quality evidence). Effects were largely maintained at follow-up for CBT versus TAU, but not for CBT versus active control. Evidence quality for CBT outcomes ranged from moderate to low. We rated evidence for AEs as very low quality for both comparisons. BT We analysed eight studies (647 participants). We found no evidence of difference between BT and active control at treatment end (pain SMD -0.67, 95% CI -2.54 to 1.20, very low-quality evidence; disability SMD -0.65, 95% CI -1.85 to 0.54, very low-quality evidence; or distress SMD -0.73, 95% CI -1.47 to 0.01, very low-quality evidence). At follow-up, effects were similar. We found no evidence of difference between BT and TAU (pain SMD -0.08, 95% CI -0.33 to 0.17, low-quality evidence; disability SMD -0.02, 95% CI -0.24 to 0.19, moderate-quality evidence; distress SMD 0.22, 95% CI -0.10 to 0.54, low-quality evidence) at treatment end. At follow-up, we found one to three studies with no evidence of difference between BT and TAU. We rated evidence for all BT versus active control outcomes as very low quality; for BT versus TAU. Evidence quality ranged from moderate to very low. We rated evidence for AEs as very low quality for BT versus active control. No studies of BT versus TAU reported AEs. ACT We analysed five studies (443 participants). There was no evidence of difference between ACT and active control for pain (SMD -0.54, 95% CI -1.20 to 0.11, very low-quality evidence), disability (SMD -1.51, 95% CI -3.05 to 0.03, very low-quality evidence) or distress (SMD -0.61, 95% CI -1.30 to 0.07, very low-quality evidence) at treatment end. At follow-up, there was no evidence of effect for pain or distress (both very low-quality evidence), but two studies showed a large benefit for reducing disability (SMD -2.56, 95% CI -4.22 to -0.89, very low-quality evidence). Two studies compared ACT to TAU at treatment end. Results should be interpreted with caution. We found large benefits of ACT for pain (SMD -0.83, 95% CI -1.57 to -0.09, very low-quality evidence), but none for disability (SMD -1.39, 95% CI -3.20 to 0.41, very low-quality evidence), or distress (SMD -1.16, 95% CI -2.51 to 0.20, very low-quality evidence). Lack of data precluded analysis at follow-up. We rated evidence quality for AEs to be very low. We encourage caution when interpreting very low-quality evidence because the estimates are uncertain and could be easily overturned.

AUTHORS' CONCLUSIONS

We found sufficient evidence across a large evidence base (59 studies, over 5000 participants) that CBT has small or very small beneficial effects for reducing pain, disability, and distress in chronic pain, but we found insufficient evidence to assess AEs. Quality of evidence for CBT was mostly moderate, except for disability, which we rated as low quality. Further trials may provide more precise estimates of treatment effects, but to inform improvements, research should explore sources of variation in treatment effects. Evidence from trials of BT and ACT was of moderate to very low quality, so we are very uncertain about benefits or lack of benefits of these treatments for adults with chronic pain; other treatments were not analysed. These conclusions are similar to our 2012 review, apart from the separate analysis of ACT.

Efficacy of Systolic Extinction Training in Fibromyalgia Patients With Elevated Blood Pressure Response to Stress: A Tailored Randomized Controlled Trial

OBJECTIVE

An intrinsic pain regulatory system is modulated by both cardiovascular dynamics that influence baroreflex sensitivity (BRS) and is diminished in fibromyalgia (FM). Baroreceptors relay cardiovascular output to the dorsal medial nucleus tractus solitarius reflex arcs that regulate pain, sleep, anxiety, and blood pressure. The aim of this study was to evaluate the effects of systolic extinction training (SET), which combines operant treatment (OT) with baroreflex training (BRT). BRT delivers peripheral electrical stimulation within a few milliseconds of the systolic or diastolic peak in the cardiac cycle. In addition, we compared SET to OT-transcutaneous electrical stimulation (TENS) independent of the cardiac cycle and aerobic exercise (AE)-BRT in FM patients with elevated blood pressure responses to stress.

METHODS

Sixty-two female patients with FM were randomized to receive either SET (n = 21), OT-TENS (n = 20), or AE-BRT (n = 21). Outcome assessments were performed before treatment (T1), after 5 weeks of treatment (T2), and after the 12-month follow-up (T3).

RESULTS

In contrast to patients receiving OT-TENS or AE-BRT, those receiving SET reported a significantly greater reduction in pain and pain interference (all P < 0.01) that was maintained at the 12-month follow-up. Clinically meaningful pain reduction at T3 was achieved in 82% of patients in the SET group, 39% of those in the OT-TENS group, and only 14% of those in the AE-BRT group. Patients in the SET group showed a significant increase (57%) in BRS following treatment, while neither the AE-BRT group or the OT-TENS group showed significant changes over time.

CONCLUSION

SET resulted in statistically significant, clinically meaningful, and long-lasting pain remission and interference compared to OT-TENS and AE-BRT. These results suggest that BRS modification is the primary mechanism of improvement. Replication of our results using larger samples and extension to other chronic pain conditions appear to be warranted.

Comparison of complex regional pain syndrome and fibromyalgia: Differences in beta and gamma bands on quantitative electroencephalography

Complex regional pain syndrome (CRPS) and fibromyalgia (FM) share many features. Both can cause severe pain and are considered to have a mechanism of action, including dysfunction of the sympathetic nervous system. However, they have clinical differences in pain range and degree. The present study aimed to find neurophysiologic differences between CRPS and FM using quantitative electroencephalography (QEEG). Thirty-eight patients with CRPS and 33 patients with FM were included in the analysis. Resting-state QEEG data were grouped into frontal, central, and posterior regions to analyze for regional differences. General linear models were utilized to test for group differences in absolute and relative powers. As a result, the CRPS group relative to FM group showed lower total absolute powers in the beta band (F = 5.159, P < .05), high beta (F = 14.120, P < .05), and gamma band (F = 15.034, P < .05). There were no significant differences between 2 groups in the delta, theta, and alpha bands. The present findings show that the CRPS and FM groups differ mainly in the high frequency, which may reflect their distinct pathophysiology and symptomatology. Our study suggests that the QEEG differences can be clinically useful in assessing brain function in patients with CRPS and FM.

Case report: Percutaneous electrical neural field stimulation in two cases of sympathetically-mediated pain

Background: Fibromyalgia and complex regional pain syndrome (CRPS) are both chronic pain syndromes with pathophysiologic mechanisms related to autonomic nervous system dysregulation and central sensitization.  Both syndromes are considered difficult to treat with conventional pain therapies. Case presentations: Here we describe a female veteran with fibromyalgia and a male veteran with CRPS, both of whom failed multiple pharmacologic, physical and psychological therapies for pain, but responded to percutaneous electrical neural field stimulation (PENFS) targeted at the auricular branches of the cranial nerves. Discussion: While PENFS applied to the body has been previously described for treatment of localized pain, PENFS effects on cranial nerve branches of the ear is not well-known, particularly when used for regional and full-body pain syndromes such as those described here. PENFS of the ear is a minimally-invasive, non-pharmacologic therapy that could lead to improved quality of life and decreased reliance on medication. However, further research is needed to guide clinical application, particularly in complex pain patients.