The use of functional neuroimaging to evaluate psychological and other non-pharmacological treatments for clinical pain

Understanding the gaps in headache and migraine treatment with psychological and behavioral interventions: A narrative review

OBJECTIVE

In this narrative review, we summarize relevant literature pertaining to psychosocial risk factors for headache and migraine progression, current behavioral and psychological treatments, and consider promising treatments.

BACKGROUND

Headache and migraine are common and associated with significant burden and disability. Current treatments targeting psychosocial risk factors show modest outcomes and do not directly address the impact of early life adversity, including the development of maladaptive emotional processing. An intervention that could address these factors and include components of current evidence-based interventions may lead to improved outcomes.

METHODS

We searched PubMed and Google Scholar for articles through December 2022. Search terms included headache, migraine, psychological interventions, behavioral interventions, cognitive-behavioral therapy, mindfulness, psychiatric comorbidities, adverse childhood experiences, trauma, and emotional processing.

RESULTS

Trauma and childhood adversity show a correlation with headache and migraine progression. Developmental adversity and trauma interfere with adaptive emotional processing, which may worsen headache and migraine symptoms, while adaptive ways of experiencing emotions are shown to improve symptoms. Current behavioral and psychological interventions, such as cognitive-behavioral and mindfulness therapies, are effective treatments for headache, but they produce small to medium effect sizes and do not directly address the impact of trauma and emotional conflicts-common factors that contribute to chronicity and disability, especially among certain subpopulations of headache patients such as those with migraine. Thus, there exists a gap in current treatment.

CONCLUSION

There is a gap in headache and migraine treatment for those patients who have a history of trauma, childhood adversity, and maladaptive emotional processing. We suggest that an integrated psychological treatment that includes components of current evidence-based interventions and addresses gaps by focusing on processing trauma-related emotions may improve chronic and debilitating symptoms.

A study based on functional near-infrared spectroscopy: Cortical responses to music interventions in patients with myofascial pain syndrome

Object

This study measured cerebral blood oxygen changes in patients with myofascial pain syndrome (MPS) using functional near-infrared spectroscopy (fNIRS). The aim was to investigate the effect of music intervention on pain relief in MPS patients.

Materials and methods

A total of 15 patients with MPS participated in this study. A self-controlled block task design was used to collect the oxy-hemoglobin ([HbO₂]) and deoxy-hemoglobin ([HbR]) concentrations in the prefrontal cortex (PFC) and motor cortex using fNIRS. The cerebral cortex response and channel connectivity were further analyzed. In the experiment, the therapist was asked to apply compression of 3-4 kg/cm² vertically using the thumb to induce pain. Soothing synthetic music with frequencies of 8-150 Hz and 50-70 dB was used as the audio for the music intervention.

Result

Compared to the group without music intervention, the activation of brain regions showed a decreasing trend in the group with music intervention under the onset of pain. The results of paired t-tests showed that nine of the data were significantly different (p < 0.05). It was also found that with music intervention, inter-channel connectivity was diminished. Besides, their dorsolateral prefrontal cortex (dlPFC) was significantly correlated with the anterior prefrontal cortex (aPFC) for pain response (r = 0.82), and weakly correlated with the premotor cortex (r = 0.40).

Conclusion

This study combines objective assessment indicators and subjective scale assessments to demonstrate that appropriate music interventions can be effective in helping to relieve pain to some extent. The analgesic mechanisms between relevant brain regions under music intervention were explored in depth. New insights into effective analgesic methods and quantitative assessment of pain conditions are presented.

Impact of hypnosis on psychophysiological measures: A scoping literature review

Exploring psychophysiological changes during hypnosis can help to better understand the nature and extent of the hypnotic phenomenon by characterizing its influence on the autonomic nervous system (ANS), in addition to its central brain effects. Hypnosis is thought to induce a relaxation response, yet studies using objective psychophysiological measures alongside hypnosis protocols show various results. We review this literature and clarify the effects of hypnosis on psychophysiological indices of ANS activity and more specifically of the stress/relaxation response, such as heart rate variability and electrodermal activity. Studies reporting psychophysical measures during hypnosis were identified by a series of Pubmed searches. Data was extracted with an interest for the influence of hypnotizability and effects of specific suggestions or tasks on the findings. We found 49 studies comprising 1315 participants, 45 concerning healthy volunteers and only 4 on patients. Sixteen compared high vs. low hypnotizable people; 30 measured heart rate, 18 measured heart rate variability, 25 electrodermal activity, and 23 respiratory signals as well as other physiological parameters. Globally, results converge to show reductions in sympathetic responses and/or increases in parasympathetic tone under hypnosis. Several methodological limitations are underscored, such as older studies (N = 16) using manual analyses, small sample sizes (<30, N = 31), as well as uncontrolled multiple comparisons. Nevertheless, we confirm that hypnosis leads to a physiological relaxation response and highlight promising avenues for this research. Suggestions are made for guiding future work in this field.

Transcutaneous auricular vague nerve stimulation improved brain connection activity on patients of disorders of consciousness: a pilot study

OBJECTIVE

To evaluate the clinical effect of transcutaneous auricular vagus nerve nerve stimulation (taVNS) on disorders of consciousness (DOC) patients with Coma Recovery Scale-Revised (CRS-R) and cerebral cortex activity by electroencephalogram (EEG) detection.

METHODS

Randomized controlled methods were used to evaluate the clinical effect of taVNS on patients with DOC. Twelve patients with initial CRS-R of 6-10 were randomly divided into the treatment group of taVNS and control group of transcutaneous non-auricular vague nerve stimulation (tnVNS). According to clinical diagnosis, the treatment group was divided into vegetative state (VS) group and minimally conscious state (MCS) group.

RESULTS

The energy of delta and beta bands is positively correlated with the brain activity of patients. taVNS has different regulatory effects on patients with different conscious States. In taVNS group, the energy of delta band in local brain regions changed significantly. Significant changes in brain connection activity were limited to local brain regions. While in patients with MCS in the taVNS group, delta and beta band energy significantly changed in multiple brain regions and cross-brain connection activity also changed significantly.

CONCLUSION

These findings suggest that taVNS may be a related extra method for arousing patients' awakening by improving brain connection activity. And the effect is remarkable in MCS patients.

Study protocol for a randomised, double-blinded, placebo-controlled phase III trial examining the add-on efficacy, cost-utility and neurobiological effects of low-dose naltrexone (LDN) in patients with fibromyalgia (INNOVA study)

INTRODUCTION

There is evidence that low-dose naltrexone (LDN; <5.0 mg/day) reduces pain and improves the quality of life of people with fibromyalgia syndrome (FMS). However, no randomised controlled trials with long-term follow-ups have been carried out. The INNOVA study will evaluate the add-on efficacy, safety, cost-utility and neurobiological effects of LDN for reducing pain in patients with FMS, with a 1-year follow-up.

METHODS AND ANALYSIS

A single-site, prospective, randomised, double-blinded, placebo-controlled, parallel design phase III trial will be performed. Eligibility criteria include being adult, having a diagnosis of FMS and experiencing pain of 4 or higher on a 10-point numerical rating scale. Participants will be randomised to a LDN intervention group (4.5 mg/day) or to a placebo control group. Clinical assessments will be performed at baseline (T0), 3 months (T1), 6 months (T2) and 12 months (T3). The primary endpoint will be pain intensity. A sample size of 60 patients per study arm (120 in total), as calculated prior to recruitment for sufficient power, will be monitored between January 2022 and August 2024. Assessment will also include daily ecological momentary evaluations of FMS-related symptoms (eg, pain intensity, fatigue and sleep disturbance), and side effects via ecological momentary assessment through the Pain Monitor app during the first 3 months. Costs and quality-adjusted life years will be also calculated. Half of the participants in each arm will be scanned with MRI at T0 and T1 for changes in brain metabolites related to neuroinflammation and central sensitisation. Inflammatory biomarkers in serum will also be measured.

ETHICS AND DISSEMINATION

This study has been approved by the Ethics Committee of the Fundació Sant Joan de Déu. The results will be actively disseminated through peer-reviewed journals, conference presentations, social media and community engagement activities.

TRIAL REGISTRATION NUMBER

NCT04739995.

Differential Brain Perfusion Changes Following Two Mind–Body Interventions for Fibromyalgia Patients: an Arterial Spin Labelling fMRI Study

Objectives

Further mechanistic insight on mind–body techniques for fibromyalgia (FMS) is needed. Arterial spin labelling (ASL) imaging can capture changes in regional cerebral blood flow (rCBF) that relate to spontaneous pain.

Methods

We recruited FMS patients undergoing either mindfulness-based stress reduction training (MBSR, n = 14) or a psychoeducational programme (FibroQoL, n = 18), and a control FMS group with no add-on treatment (n = 14). We acquired whole-brain rCBF maps and self-report measures at baseline and following treatment and explored interaction effects in brain perfusion between the treatment group and session with a focus on the amygdala, the insula and the anterior cingulate cortex (ACC).

Results

We identified a significant interaction effect in the amygdala, which corresponded with rCBF decreases following FibroQoL specifically. At baseline, rCBF in the amygdala for the FibroQoL group correlated with pain catastrophizing and anxiety scores, but not after treatment, suggesting a decoupling between activity in the amygdala and negative emotional symptoms of FMS as a consequence of treatment. Baseline rCBF correlated positively with pain symptoms in the ACC and the anterior insula across all patients; moreover, the correlation between rCBF changes post intervention in the insula and pain improvement was negative for both treatments and significantly different from the control group. We suggest that there is disruption of the typical relationship between clinical pain and activity as a product of these two nonpharmacological therapies.

Conclusions

We have demonstrated that different mind-to-body treatments correspond to differential changes in clinical symptoms and brain activity patterns, which encourages future research investigating predictors of treatment response.

Trial Registration

 NCT02561416.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12671-021-01806-2.

Repetitive Transcranial Magnetic Stimulation for Neuropathic Pain on the Non-Motor Cortex: An Evidence Mapping of Systematic Reviews

OBJECTIVE

This study was aimed to summarize and analyze the quality of the available evidence in systematic reviews (SRs) of repetitive transcranial magnetic stimulation (rTMS) on the non-motor cortex (non-M1) for neuropathic pain (NP) through an evidence mapping approach.

METHODS

We follow the Global Evidence Mapping (GEM) methodology. Searches were conducted in PubMed, EMBASE, Epistemonikos, and the Cochrane Library. The study type was restricted to SRs with or without meta-analysis. All literature published before January 23, 2021, were included. The methodological quality of the included SRs was assessed using A Measurement Tool to Assess Systematic Reviews (AMSTAR-2). Data were extracted according to a defined population-intervention-comparison-outcome (PICO) framework from primary studies that included SRs. The same PICO was categorized into PICOs according to interventions (stimulation target, frequency, number of sessions (short: 1-5 sessions, medium: 5-10 sessions, and long: >10 sessions)) and comparison (sham rTMS or other targets). The evidence mapping was presented in tables and a bubble plot.

RESULTS

A total of 23 SRs were included. According to the AMSTAR-2, 20 SRs scored "very low" in terms of methodological quality, 2 SRs scored "low," and 1 SR scored "high." A total of 17 PICOs were extracted. The dorsolateral prefrontal cortex (DLPFC) is the most studied of the non-motor cortex targets. PICOs of DLPFC, premotor cortex (PMC), frontal cortex, and secondary somatosensory cortex (S2) were mainly categorized with a "potentially better" conclusion. High-frequency (5-20 Hz) rTMS of non-M1 usually lead to "potentially better" conclusions.

CONCLUSIONS

DLPFC, PMC, frontal cortex, and S2 seem to be promising new targets for rTMS treatment of certain NP. Evidence mapping is a useful and reliable methodology to identify and present the existing evidence gap that more research efforts are necessary in order to highlight the optimal stimulation protocols for non-M1 targets and standardize parameters to fill the evidence gaps of rTMS. Further investigation is advised to improve the methodological quality and the reporting process of SRs.

Molecular mechanism in trigeminal nerve and treatment methods related to orthodontic pain

BACKGROUND

Orthodontic treatment is the main treatment approach for malocclusion. Orthodontic pain is an inevitable undesirable adverse reaction during orthodontic treatment. It is reported orthodontic pain has become one of the most common reason that patients withdraw from orthodontic treatment. Therefore, understanding the underlying mechanism and finding treatment of orthodontic pain are in urgent need.

AIMS

This article aims to sort out the mechanisms and treatments of orthodontic pain, hoping to provide some ideas for future orthodontic pain relief.

MATERIALS

Tooth movement will cause local inflammation. Certain inflammatory factors and cytokines stimulating the trigeminal nerve and further generating pain perception, as well as drugs and molecular targeted therapy blocking nerve conduction pathways, will be reviewed in this article.

METHOD

We review and summaries current studies related to molecular mechanisms and treatment approaches in orthodontic pain control.

RESULTS

Orthodontics pain related influencing factors and molecular mechanisms has been introduced. Commonly used clinical methods in orthodontic pain control has been evaluated.

DISCUSSION

With the clarification of more molecular mechanisms, the direction of orthodontic pain treatment will shift to targeted drugs.

Aberrant Intraregional Brain Activity and Functional Connectivity in Patients With Diarrhea-Predominant Irritable Bowel Syndrome

Background and Purpose

The appearance and aggravation of diarrhea-predominant irritable bowel syndrome (IBS-D) have proven to be closely related to psychosocial factors. We aimed to measure altered spontaneous brain activity and functional connectivity (FC) in patients with IBS-D using resting-state functional magnetic resonance imaging (RS-fMRI) and to analyze the relationship between these parameters and emotional symptoms.

Methods

Thirty-six adult IBS-D patients and thirty-six demographic-matched healthy controls (HCs) underwent RS-fMRI scans. After processing RS-fMRI data, the values of the amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) of the two groups were compared. The abnormal regions were selected as the regions of interest to compare whole-brain seed-based FC between the groups. The relationships between RS-fMRI data and mood and gastrointestinal symptoms were analyzed using correlation and mediation analyses.

Results

Compared with HCs, IBS-D patients showed increased ALFF in the right cerebellum posterior lobe, the right lingual gyrus/calcarine, the right postcentral gyrus, the right superior frontal gyrus (SFG), and middle frontal gyrus (MFG), with decreased ALFF in the right inferior parietal lobule, the right striatum, the right anterior cingulated cortex, the right insula, the right hippocampus, the right thalamus, the right midbrain, and the left precuneus. IBS-D patients showed increased ReHo in the bilateral lingual gyrus/calcarine, the bilateral SFG, the right MFG, and the right postcentral gyrus, with decreased ReHo in the orbital part of the left inferior frontal gyrus and the right supplementary motor area. Patients showed enhanced FC between the left precuneus and the bilateral orbitofrontal cortex (OFC). There was a positive correlation between increased ALFF values in the right midbrain and anxiety-depression symptoms in IBS-D patients, and the mediating effect of gastrointestinal symptoms indirectly caused this correlation.

Conclusion

IBS-D patients had dysregulated spontaneous activity and FC in regions related to pain regulation and emotional arousal involved in prefrontal–limbic–midbrain circuit and somatosensory processing. The development of mood disorders in IBS-D patients may be partly related to the dysfunction of components in the dopamine pathway (especially the midbrain, OFC) due to visceral pain.

Optimizing Chronic Pain Treatment with Enhanced Neuroplastic Responsiveness: A Pilot Randomized Controlled Trial

Chronic pain affects mental and physical health and alters brain structure and function. Interventions that reduce chronic pain are also associated with changes in the brain. A number of non-invasive strategies can promote improved learning and memory and increase neuroplasticity in older adults. Intermittent fasting and glucose administration represent two such strategies with the potential to optimize the neurobiological environment to increase responsiveness to recognized pain treatments. The purpose of the pilot study was to test the feasibility and acceptability of intermittent fasting and glucose administration paired with a recognized pain treatment activity, relaxation and guided imagery. A total of 32 adults (44% W, 56% M), 50 to 85 years of age, with chronic knee pain for three months or greater participated in the study. Four sessions were completed over an approximate two-week period. Findings indicate the ability to recruit, randomize, and retain participants in the protocol. The procedures and measures were reasonable and completed without incident. Participant adherence was high and exit interview feedback positive. In summary, the pilot study was feasible and acceptable, providing the evidence necessary to move forward with a larger clinical trial.

Addition of corticosteroids to local anaesthetics for chronic non-cancer pain injections: a systematic review and meta-analysis of randomised controlled trials

BACKGROUND

Despite common use, the benefit of adding steroids to local anaesthetics (SLA) for chronic non-cancer pain (CNCP) injections is uncertain. We performed a systematic review and meta-analysis of English-language RCTs to assess the benefit and safety of adding steroids to local anaesthetics (LA) for CNCP.

METHODS

We searched MEDLINE, EMBASE, and CENTRAL databases from inception to May 2019. Trial selection and data extraction were performed in duplicate. Outcomes were guided by the Initiative in Methods, Measurements, and Pain Assessment in Clinical Trials (IMMPACT) statement with pain improvement as the primary outcome and pooled using random effects model and reported as relative risks (RR) or mean differences (MD) with 95% confidence intervals (CIs).

RESULTS

Among 5097 abstracts, 73 trials were eligible. Although SLA increased the rate of success (42 trials, 3592 patients; RR=1.14; 95% CI, 1.03-1.25; number needed to treat [NNT], 13), the effect size decreased by nearly 50% (NNT, 22) with the removal of two intrathecal injection studies. The differences in pain scores with SLA were not clinically meaningful (54 trials, 4416 patients, MD=0.44 units; 95% CI, 0.24-0.65). No differences were observed in other outcomes or adverse events. No subgroup effects were detected based on clinical categories. Meta-regression showed no significant association with steroid dose or length of follow-up and pain relief.

CONCLUSIONS

Addition of cortico steroids to local anaesthetic has only small benefits and a potential for harm. Injection of local anaesthetic alone could be therapeutic, beyond being diagnostic. A shared decision based on patient preferences should be considered. If used, one must avoid high doses and series of steroid injections.

CLINICAL TRIAL REGISTRATION

PROSPERO #: CRD42015020614.

Intracortical Inhibition in the Affected Hemisphere in Limb Amputation

Phantom limb pain (PLP) affects up to 80% of amputees. Despite the lack of consensus about the etiology and pathophysiology of phantom experiences, previous evidence pointed out the role of changes in motor cortex excitability as an important factor associated with amputation and PLP. In this systematic review, we investigated changes in intracortical inhibition as indexed by transcranial magnetic stimulation (TMS) in amputees and its relationship to pain. Four electronic databases were screened to identify studies using TMS to measure cortical inhibition, such as short intracortical inhibition (SICI), long intracortical inhibition (LICI) and cortical silent period (CSP). Seven articles were included and evaluated cortical excitability comparing the affected hemisphere with the non-affected hemisphere or with healthy controls. None of them correlated cortical disinhibition and clinical parameters, such as the presence or intensity of PLP. However, most studies showed decreased SICI in amputees affected hemisphere. These results highlight that although SICI seems to be changed in the affected hemisphere in amputees, most of the studies did not investigate its clinical correlation. Thus, the question of whether they are a valid diagnostic marker remains unanswered. Also, the results were highly variable for both measurements due to the heterogeneity of study designs and group comparisons in each study. Although these results underscore the role of inhibitory networks after amputation, more studies are needed to investigate the role of a decreased inhibitory drive in the motor cortex to the cause and maintenance of PLP.

Role of brain imaging in disorders of brain-gut interaction: a Rome Working Team Report

Imaging of the living human brain is a powerful tool to probe the interactions between brain, gut and microbiome in health and in disorders of brain-gut interactions, in particular IBS. While altered signals from the viscera contribute to clinical symptoms, the brain integrates these interoceptive signals with emotional, cognitive and memory related inputs in a non-linear fashion to produce symptoms. Tremendous progress has occurred in the development of new imaging techniques that look at structural, functional and metabolic properties of brain regions and networks. Standardisation in image acquisition and advances in computational approaches has made it possible to study large data sets of imaging studies, identify network properties and integrate them with non-imaging data. These approaches are beginning to generate brain signatures in IBS that share some features with those obtained in other often overlapping chronic pain disorders such as urological pelvic pain syndromes and vulvodynia, suggesting shared mechanisms. Despite this progress, the identification of preclinical vulnerability factors and outcome predictors has been slow. To overcome current obstacles, the creation of consortia and the generation of standardised multisite repositories for brain imaging and metadata from multisite studies are required.

Brain mechanisms impacted by psychological therapies for pain: identifying targets for optimization of treatment effects

Psychological therapies, such as cognitive behavioral therapy, are widely used multifaceted approaches that have been shown to improve pain-related functioning. A small but growing number of studies have used brain imaging to support the use of psychological therapies for pain. Although these studies have led to an increased understanding of how therapies may engage neural systems, there are multiple technical and conceptual challenges to consider. Based on the current literature, several components of effective psychological therapies for pain may be supported by changes in neural circuitry, which are most consistently represented by diminished activation and/or reduced hyperconnectivity in brain regions related to pain processing, emotion, and cognitive control. Findings may vary based on methodological approaches used and may also differ depending on targets of treatment. To provide a nuanced understanding of the current literature, specific targets and components of effective treatments for which a neural basis has been investigated are reviewed. These treatment components include catastrophic thinking about pain, increasing self-efficacy, mindfulness, anxiety symptom reduction, and exposure-based approaches. In general, such strategies have the potential to normalize regional hyperactivations and reduce hyperconnectivity in brain regions associated with nociceptive processing, cognition, and emotion, although additional research is needed. By determining if there are indeed distinct brain mechanisms engaged by different components of psychological therapy and evidence for specific changes in neural function after these interventions, future therapies may be more optimally tailored for individuals afflicted with chronic pain.

Chronic stress increases pain sensitivity via activation of the rACC-BLA pathway in rats

Exposure to chronic stress can produce maladaptive neurobiological changes in pathways associated with pain processing, which may cause stress-induced hyperalgesia (SIH). However, the underlying mechanisms still remain largely unknown. In previous studies, we have reported that the amygdala is involved in chronic forced swim (FS) stress-induced depressive-like behaviors and the exacerbation of neuropathic pain in rats, of which, the basolateral amygdala (BLA) and the central nucleus of the amygdala (CeA) are shown to play important roles in the integration of affective and sensory information including nociception. Here, using in vivo multichannel recording from rostal anterior cingulate cortex (rACC) and BLA, we found that chronic FS stress (CFSS) could increase the pain sensitivity of rats in response to low intensity innoxious stimuli (LIS) and high intensity noxious stimuli (HNS) imposed upon the hindpaw, validating the occurrence of SIH in stressed rats. Moreover, we discovered that CFSS not only induced an increased activity of rACC neuronal population but also produced an augmented field potential power (FPP) of rACC local field potential (LFP), especially in low frequency theta band as well as in high frequency low gamma band ranges, both at the baseline state and under LIS and HNS conditions. In addition, by using a cross-correlation method and a partial directed coherence (PDC) algorithm to analyze the LFP oscillating activity in rACC and BLA, we demonstrated that CFSS could substantially promote the synchronization between rACC and BLA regions, and also enhanced the neural information flow from rACC to BLA. We conclude that exposure of chronic FS stress to rats could result in an increased activity of rACC neuronal population and promote the functional connectivity and the synchronization between rACC and BLA regions, and also enhance the pain-related neural information flow from rACC to BLA, which likely underlie the pathogenesis of SIH.

Executive Functioning Mediates the Relationship Between Pain Coping and Quality of Life in Youth With Sickle Cell Disease

Objective

Sickle cell disease (SCD) is a lifelong condition characterized by pain, which is associated with reduced health-related quality of life (HRQL). Data suggest that patients with SCD vary in how they cope and their neurocognitive abilities. This study aimed to characterize executive functioning and pain coping styles in children with SCD experiencing a range of pain frequency (i.e., chronic, episodic, and asymptomatic) and to examine whether executive functioning mediates the relationship between pain coping and HRQL.

Method

Participants included 100 children and adolescents with SCD between the ages of 8 and 18 years (M = 13.53, SD = 2.8) and their parents who were recruited during outpatient SCD clinic visits in a children's hospital. Children completed questionnaires related to pain experience and pain coping. Parents completed questionnaires about demographic information, their child's executive functioning, and HRQL.

Results

Pain intensity, executive dysfunction, and engagement in emotion-focused coping (i.e., internalizing/catastrophizing and externalizing) predicted poor HRQL. In addition, engagement in emotion-focused coping predicted executive dysfunction. Multivariate analysis of covariance revealed executive functioning did not differ based on pain frequency; however, executive functioning was a significant mediator that helped explain the relationships between distraction and emotion-focused coping techniques on HRQL.

Conclusion

Findings support that executive functioning is an important factor in understanding the relationship between pain coping and HRQL in youth with SCD. Future research is warranted to examine the potential impact of executive functioning on the utility of interventions targeting adaptive pain coping in youth with SCD.

Opioid-Independent and Opioid-Mediated Modes of Pain Modulation

Pain is regulated endogenously through both opioid and non-opioid mechanisms. We hypothesized that two novel pain modulation tasks, one drawing on context/expectations and one using voluntary reappraisal, would show differing levels of opioid dependence. Specifically, we expected that naloxone would block context-related analgesia, whereas mental imagery-based pain reappraisal would be opioid-independent.A double-blind, placebo-controlled intravenous naloxone versus saline crossover design was used. Twenty healthy volunteers completed the two modulation tasks with acute heat stimuli calibrated to induce moderate pain. In the mental imagery task, participants imagined either a "pleasant" or a "comparison" scenario during painful heat. In the relative relief task, moderate heat stimuli coincided with visual cues eliciting relief from the expectation of intense pain, and were compared with moderate heat stimuli delivered under the expectation of non-painful warmth. Both "pleasant imagery" and "relative relief" conditions significantly improved ratings of pain intensity and pleasantness during saline treatment. Indeed, the target stimuli in both tasks, which had been calibrated to induce moderate pain, were rated as mildly pleasant. Furthermore, consistently with the main hypothesis, blocking endogenous opioid signaling with naloxone did not significantly affect imagery-induced regulation of pain intensity or pleasantness. In contrast, the relative relief-induced pain regulation (i.e., context/expectation) was blocked by naloxone. We conclude that endogenous opioid signaling is necessary for expectation-related relative relief analgesia, but not for pain reappraisal through mental imagery. These results support mental imagery as a powerful and clinically relevant strategy for regulating pain affect also in patients where endogenous opioid mechanisms might be compromised.SIGNIFICANCE STATEMENT Neurotransmitter systems in the human brain can be probed through antagonist drugs. Studies using the opioid antagonist naloxone have demonstrated that the brain relies on both opioid and non-opioid mechanisms to downregulate pain. This holds clinical relevance given altered endogenous opioid processes in many chronic pain conditions. The present study used a double-blinded, placebo-controlled naloxone blockage of endogenous opioids in healthy humans to show differential opioid involvement in two pain modulation tasks. Context/expectation-driven (relative relief-related) analgesia was blocked by naloxone. In contrast, pain reappraisal through mental imagery was intact despite opioid receptor blockade, suggesting opioid independence. These results support mental imagery as a powerful, clinically relevant strategy for regulating pain as it does not rely on a functioning opioidergic system.

State of the Art Management of Acute Vaso-occlusive Pain in Sickle Cell Disease

Acute vaso-occlusive crisis (VOC) is a hallmark of sickle cell disease (SCD). Multiple complex pathophysiological processes can result in pain during a VOC. Despite significant improvements in the understanding and management of SCD, little progress has been made in the management of pain in SCD, although new treatments are being explored. Opioids and non-steroidal anti-inflammatory drugs (NSAIDs) remain the mainstay of treatment of VOC pain, but new classes of drugs are being tested to prevent and treat acute pain. Advancements in the understanding of the pathophysiology of SCD and pain and the pharmacogenomics of opioids have yet to be effectively utilized in the management of VOC. Opioid tolerance and opioid-induced hyperalgesia are significant problems associated with the long-term use of opioids, and better strategies for chronic pain therapy are needed. This report reviews the mechanisms of pain associated with acute VOC, describes the current management of VOC, and describes some of the new therapies under evaluation for the management of acute VOC in SCD.

Efficacy of Self-hypnosis on Quality of Life For Children with Chronic Pain Syndrome

The aim of this study was to assess the efficacy of self-hypnosis in a therapeutic education program (TEP) for the management of chronic pain in 26 children aged 7 to 17 years. Outcomes of the study were a total or a partial (at least 1) achievement of the therapeutic goals (pain, quality of sleeping, schooling, and functional activity). Sixteen patients decreased their pain intensity, 10 reached all of their therapeutic goals, and 9 reached them partially. Self-hypnosis was the only component of the TEP associated with these improvements. The current study supports the efficacy of self-hypnosis in our TEP program for chronic pain management in children.

Active pain coping is associated with the response in real-time fMRI neurofeedback during pain

Real-time functional magnetic resonance imaging (rt-fMRI) neurofeedback is used as a tool to gain voluntary control of activity in various brain regions. Little emphasis has been put on the influence of cognitive and personality traits on neurofeedback efficacy and baseline activity. Here, we assessed the effect of individual pain coping on rt-fMRI neurofeedback during heat-induced pain. Twenty-eight healthy subjects completed the Coping Strategies Questionnaire (CSQ) prior to scanning. The first part of the fMRI experiment identified target regions using painful heat stimulation. Then, subjects were asked to down-regulate the pain target brain region during four neurofeedback runs with painful heat stimulation. Functional MRI analysis included correlation analysis between fMRI activation and pain ratings as well as CSQ ratings. At the behavioral level, the active pain coping (first principal component of CSQ) was correlated with pain ratings during neurofeedback. Concerning neuroimaging, pain sensitive regions were negatively correlated with pain coping. During neurofeedback, the pain coping was positively correlated with activation in the anterior cingulate cortex, prefrontal cortex, hippocampus and visual cortex. Thermode temperature was negatively correlated with anterior insula and dorsolateral prefrontal cortex activation. In conclusion, self-reported pain coping mechanisms and pain sensitivity are a source of variance during rt-fMRI neurofeedback possibly explaining variations in regulation success. In particular, active coping seems to be associated with successful pain regulation.

Optimizing delivery of a behavioral pain intervention in cancer patients using a sequential multiple assignment randomized trial SMART

BACKGROUND/AIMS

Pain is common in cancer patients and results in lower quality of life, depression, poor physical functioning, financial difficulty, and decreased survival time. Behavioral pain interventions are effective and nonpharmacologic. Traditional randomized controlled trials (RCT) test interventions of fixed time and dose, which poorly represent successive treatment decisions in clinical practice. We utilize a novel approach to conduct a RCT, the sequential multiple assignment randomized trial (SMART) design, to provide comparative evidence of: 1) response to differing initial doses of a pain coping skills training (PCST) intervention and 2) intervention dose sequences adjusted based on patient response. We also examine: 3) participant characteristics moderating intervention responses and 4) cost-effectiveness and practicality.

METHODS/DESIGN

Breast cancer patients (N=327) having pain (ratings≥5) are recruited and randomly assigned to: 1) PCST-Full or 2) PCST-Brief. PCST-Full consists of 5 PCST sessions. PCST-Brief consists of one 60-min PCST session. Five weeks post-randomization, participants re-rate their pain and are re-randomized, based on intervention response, to receive additional PCST sessions, maintenance calls, or no further intervention. Participants complete measures of pain intensity, interference and catastrophizing.

CONCLUSIONS

Novel RCT designs may provide information that can be used to optimize behavioral pain interventions to be adaptive, better meet patients' needs, reduce barriers, and match with clinical practice. This is one of the first trials to use a novel design to evaluate symptom management in cancer patients and in chronic illness; if successful, it could serve as a model for future work with a wide range of chronic illnesses.

Increased Interstitial Concentrations of Glutamate and Pyruvate in Vastus Lateralis of Women with Fibromyalgia Syndrome Are Normalized after an Exercise Intervention - A Case-Control Study

BACKGROUND

Fibromyalgia syndrome (FMS) is associated with central alterations, but controversies exist regarding the presence and role of peripheral factors. Microdialysis (MD) can be used in vivo to study muscle alterations in FMS. Furthermore for chronic pain conditions such as FMS, the mechanisms for the positive effects of exercise are unclear. This study investigates the interstitial concentrations of algesics and metabolites in the vastus lateralis muscle of 29 women with FMS and 28 healthy women before and after an exercise intervention.

METHODS

All the participants went through a clinical examination and completed a questionnaire. In addition, their pressure pain thresholds (PPTs) in their upper and lower extremities were determined. For both groups, MD was conducted in the vastus lateralis muscle before and after a 15-week exercise intervention of mainly resistance training of the lower limbs. Muscle blood flow and interstitial muscle concentrations of lactate, pyruvate, glutamate, glucose, and glycerol were determined.

RESULTS

FMS was associated with significantly increased interstitial concentrations of glutamate, pyruvate, and lactate. After the exercise intervention, the FMS group exhibited significant decreases in pain intensity and in mean interstitial concentrations of glutamate, pyruvate, and glucose. The decrease in pain intensity in FMS correlated significantly with the decreases in pyruvate and glucose. In addition, the FMS group increased their strength and endurance.

CONCLUSION

This study supports the suggestion that peripheral metabolic and algesic muscle alterations are present in FMS patients and that these alterations contribute to pain. After an exercise intervention, alterations normalized, pain intensity decreased (but not abolished), and strength and endurance improved, all findings that suggest the effects of exercise are partially peripheral.

POSTOPERATIVE PAIN: MANAGEMENT AND DOCUMENTATION BY IRANIAN NURSES

Background:

Pain is one of the most common symptoms experienced by patients after surgeries. Inadequate postoperative pain management is an international problem and the need to improve its management is well documented. The aim of the study was to assess nursing reports related to the patients’ pain intensity and quality, concomitant symptoms, use of scales in pain assessment, and compliance with the national guideline after surgery.

Methods:

This study was a retrospective cohort; samples were nurse records of patients who had elective surgery.

Result:

Only 6% of the patients’ pain records included pain intensity which was not measured with standard scales. More than half of all injections were opioid analgesic which is in contrast to the guidelines of the Iranian Ministry of Health. Pain assessment was higher in women and by nurses with more than 15 years of working experience.

Conclusion:

to conclude, the patients’ pain was not assessed properly in terms of intensity, quality, and associated symptoms. Therefore, training and motivating nurses is very important in this context and should be incorporated in nurses’ academic and continuous educational courses.

The mechanism of neurofeedback training for treatment of central neuropathic pain in paraplegia: a pilot study

Background

Central neuropathic pain has a prevalence of 40 % in patients with spinal cord injury. Electroencephalography (EEG) studies showed that this type of pain has identifiable signatures, that could potentially be targeted by a neuromodulation therapy. The aim of the study was to investigate the putative mechanism of neurofeedback training on central neuropathic pain and its underlying brain signatures in patients with chronic paraplegia.

Methods

Patients’ EEG activity was modulated from the sensory-motor cortex, electrode location C3/Cz/C4/P4 in up to 40 training sessions Results. Six out of seven patients reported immediate reduction of pain during neurofeedback training. Best results were achieved with suppressing Ɵ and higher β (20–30 Hz) power and reinforcing α power at C4. Four patients reported clinically significant long-term reduction of pain (>30 %) which lasted at least a month beyond the therapy. EEG during neurofeedback revealed a wide spread modulation of power in all three frequency bands accompanied with changes in the coherence most notable in the beta band. The standardized low resolution electromagnetic tomography analysis of EEG before and after neurofeedback therapy showed the statistically significant reduction of power in beta frequency band in all tested patients. Areas with reduced power included the Dorsolateral Prefrontal Cortex, the Anterior Cingulate Cortex and the Insular Cortex.

Conclusions

Neurofeedback training produces both immediate and longer term reduction of central neuropathic pain that is accompanied with a measurable short and long term modulation of cortical activity. Controlled trials are required to confirm the efficacy of this neurofeedback protocol on treatment of pain. The study is a registered UKCRN clinical trial Nr 9824.

Cognitive behavioral therapy eases orthodontic pain: EEG states and functional connectivity analysis

OBJECTIVES

To assess the effects of CBT on electroencephalogram activity in patients with orthodontic pain.

METHODS

We recruited 24 young (18-28 years), healthy individuals with matched baseline characteristics, including pain intensity, anxiety levels, personality traits, and life-quality scores. Participants were randomly assigned to either the CBT intervention group (n = 12) or the blank control group (n = 12). Multichannel continuous electroencephalogram signals and visual analog scale (VAS) scores were recorded before and after initial archwire placement for 1 week. A 1-month follow-up was conducted, when participants' daily VAS scores were recorded.

RESULTS

The overall EEG spectral power of the CBT group was lower than that of the control group, especially in the theta (4-7 Hz) and beta (14-30 Hz) bands during the treatment period. An enhanced coupling of theta and beta frequencies was observed in frontal and occipital electrodes, respectively. The EEG power in delta and theta bands correlated positively with pain intensity. Network coherence for the CBT group exhibited higher connectivity in the theta band.

CONCLUSIONS

Specific cerebral responses to CBT instructions could be detected with continuous electroencephalograms and related to orthodontic pain processing, which may provide a new insight in exploring CBT for orthodontic pain control.

Distraction Analgesia in Chronic Pain Patients

Background:

Diverting attention away from noxious stimulation (i.e., distraction) is a common pain-coping strategy. Its effects are variable across individuals, however, and the authors hypothesized that chronic pain patients who reported higher levels of pain catastrophizing would derive less pain-reducing benefit from distraction.

Methods:

Chronic pain patients (n = 149) underwent psychometric and quantitative sensory testing, including assessment of the temporal summation of pain in the presence and absence of a distracting motor task.

Results:

A simple distraction task decreased temporal summation of pain overall, but, surprisingly, a greater distraction analgesia was observed in high catastrophizers. This enhanced distraction analgesia in high catastrophizers was not altered when controlling for current pain scores, depression, anxiety, or opioid use (analysis of covariance [ANCOVA]: F = 8.7, P &lt; 0.005). Interestingly, the magnitude of distraction analgesia was inversely correlated with conditioned pain modulation (Pearson R = −0.23, P = 0.005).

Conclusion:

Distraction produced greater analgesia among chronic pain patients with higher catastrophizing, suggesting that catastrophizing’s pain-amplifying effects may be due in part to greater attention to pain, and these patients may benefit from distraction-based pain management approaches. Furthermore, these data suggest that distraction analgesia and conditioned pain modulation may involve separate underlying mechanisms.

Cognitive and emotional control of pain and its disruption in chronic pain

Chronic pain is one of the most prevalent health problems in our modern world, with millions of people debilitated by conditions such as back pain, headache and arthritis. To address this growing problem, many people are turning to mind-body therapies, including meditation, yoga and cognitive behavioural therapy. This article will review the neural mechanisms underlying the modulation of pain by cognitive and emotional states - important components of mind-body therapies. It will also examine the accumulating evidence that chronic pain itself alters brain circuitry, including that involved in endogenous pain control, suggesting that controlling pain becomes increasingly difficult as pain becomes chronic.

The neural correlates of regulating positive and negative emotions in medication-free major depression

Depressive cognitive schemas play an important role in the emergence and persistence of major depressive disorder (MDD). The current study adapted emotion regulation techniques to reflect elements of cognitive behavioural therapy (CBT) and related psychotherapies to delineate neurocognitive abnormalities associated with modulating the negative cognitive style in MDD. Nineteen non-medicated patients with MDD and 19 matched controls reduced negative or enhanced positive feelings elicited by emotional scenes while undergoing functional magnetic resonance imaging. Although both groups showed significant emotion regulation success as measured by subjective ratings of affect, the controls were significantly better at modulating both negative and positive emotion. Both groups recruited regions of dorsolateral prefrontal cortex and ventrolateral prefrontal cortex (VLPFC) when regulating negative emotions. Only in controls was this accompanied by reduced activity in sensory cortices and amygdala. Similarly, both groups showed enhanced activity in VLPFC and ventral striatum when enhancing positive affect; however, only in controls was ventral striatum activity correlated with regulation efficacy. The results suggest that depression is associated with both a reduced capacity to achieve relief from negative affect despite recruitment of ventral and dorsal prefrontal cortical regions implicated in emotion regulation, coupled with a disconnect between activity in reward-related regions and subjective positive affect.

An fMRI study exploring the overlap and differences between neural representations of physical and recalled pain

Implementing a recall paradigm without hypnosis, we use functional MRI (fMRI) to explore and compare nociceptive and centrally-driven pain experiences. We posit that a trace of a recent nociceptive event can be used to create sensory-re-experiencing of pain that can be qualified in terms of intensity and vividness. Fifteen healthy volunteers received three levels of thermal stimuli (warm, low pain and high pain) and subsequently were asked to recall and then rate this experience. Neuroimaging results reveal that recalling a previous sensory experience activates an extensive network of classical pain processing structures except the contralateral posterior insular cortex. Nociceptive-specific activation of this structure and the rated intensity difference between physical and recalled pain events allow us to investigate the link between the quality of the original nociceptive stimulus and the mental trace, as well as the differences between the accompanying neural responses. Additionally, by incorporating the behavioural ratings, we explored which brain regions were separately responsible for generating either an accurate or vivid recall of the physical experience. Together, these observations further our understanding of centrally-mediated pain experiences and pain memory as well as the potential relevance of these factors in the maintenance of chronic pain.