Everyday Executive Functioning in Chronic Pain: Specific Deficits in Working Memory and Emotion Control, Predicted by Mood, Medications, and Pain Interference

Hippocampal cannabinoid type 2 receptor alleviates chronic neuropathic pain-induced cognitive impairment via microglial DUSP6 pathway in rats

Approximately 50% of patients with chronic neuropathic pain experience cognitive impairment, which negatively impacts their quality of life. The cannabinoid type 2 receptor (CB2R) may be involved in hippocampal cognitive processes. However, its role in chronic neuropathic pain-induced cognitive impairment remains elusive. Spared nerve injury (SNI) was used to induce chronic neuropathic pain in rats, while the novel-object recognition test and the Y-maze test were employed to assess cognitive function. Immunofluorescence, western blotting, and stereotaxic hippocampal microinjection were utilized to elucidate the potential mechanisms. We observed a reduction in mechanical pain threshold and cognitive impairment in SNI rats. This was accompanied by a tendency for hippocampal microglia to adopt pro-inflammatory functions. Notably, no changes were detected in CB2R expression. However, downregulation of the endogenous ligands AEA and 2-AG was evident. Hippocampal microinjection of a CB2R agonist mitigated cognitive impairment in SNI rats, which correlated with a tendency for microglia to adopt anti-inflammatory functions. Additionally, SNI-induced activation of the p-ERK/NFκB pathway in the hippocampus. Activation of CB2R reversed this process by upregulating DUSP6 expression in microglia. The effects elicited by CB2R activation could be inhibited through the downregulation of microglial DUSP6 via hippocampal adeno-associated virus (AAV) microinjection. Conversely, overexpression of hippocampal DUSP6 using AAV ameliorated the cognitive deficits observed in SNI rats, which remained unaffected by the administration of a CB2R antagonist. Our findings demonstrate that activation of hippocampal CB2R can mitigate chronic neuropathic pain-induced cognitive impairment through the modulation of the DUSP6/ERK/NFκB pathway.

The evolving pathophysiology of TBI and the advantages of temporally-guided combination therapies

Several clinical and experimental studies have demonstrated that traumatic brain injury (TBI) activates cascades of biochemical, molecular, structural, and pathological changes in the brain. These changes combine to contribute to the various outcomes observed after TBI. Given the breadth and complexity of changes, combination treatments may be an effective approach for targeting multiple detrimental pathways to yield meaningful improvements. In order to identify targets for therapy development, the temporally evolving pathophysiology of TBI needs to be elucidated in detail at both the cellular and molecular levels, as it has been shown that the mechanisms contributing to cognitive dysfunction change over time. Thus, a combination of individual mechanism-based therapies is likely to be effective when maintained based on the time courses of the cellular and molecular changes being targeted. In this review, we will discuss the temporal changes of some of the key clinical pathologies of human TBI, the underlying cellular and molecular mechanisms, and the results from preclinical and clinical studies aimed at mitigating their consequences. As most of the pathological events that occur after TBI are likely to have subsided in the chronic stage of the disease, combination treatments aimed at attenuating chronic conditions such as cognitive dysfunction may not require the initiation of individual treatments at a specific time. We propose that a combination of acute, subacute, and chronic interventions may be necessary to maximally improve health-related quality of life (HRQoL) for persons who have sustained a TBI.

Separate and combined associations of cognitive impairment and body pain with functional and mobility disabilities among older women and men in India

This study examined the separate and combined associations of cognitive impairment and body pain with functional and mobility disabilities (FMDs) among older women and men in India. Multivariable linear regression models were applied using data from the Longitudinal Aging Study in India (2017-18) comprising 31,464 adults aged 60+. Older adults with cognitive impairment and pain reported higher levels of FMDs than peers without any pain and cognitive impairment. The likelihood of FMDs was significantly greater among older Indians enduring both cognitive impairment and pain (p < 0.05). Moreover, the association between cognitive impairment and functional disability was noticeably stronger in older women, particularly those with frequent pain, while the link between cognitive impairment and mobility disability was more pronounced in men with pain. Integrated cognitive rehabilitation and pain management programs, along with guided physical therapy, gender-specific support groups, and community-based health promotion activities, should be considered to reduce FMDs in older Indians.

Understanding the Associations between Executive Function and Psychological Variables in Fibromyalgia Syndrome: A Network Analysis Approach

The aim of this study was to quantify the multivariate relationships between clinical, cognitive performance, executive functioning, and psychological outcomes in women with fibromyalgia (FMS) using network analyses. Demographic (age, height, weight), clinical (pain history, pain intensity, and related disability), neurocognitive (D2 Attention test, Rey-Osterrieth Complex Figure for visual perception, "Digits D/R/I" tests of the WAIS-IV battery for working memory, the 5-Digit Test for mental inhibition, the Symbol Search for processing speed and the Zoo Test for planning/decision making) and psychological (depressive symptoms, anxiety levels, sleep quality, pain hypervigilance) variables were collected in 129 women with FMS and 111 healthy women. Network analyses were conducted separately for each group to quantify the adjusted correlations between the modeled variables and to assess their centrality indices (i.e., connectivity with other symptoms in the network and their importance in the network). The network identified 74 associations in FMS women and 46 associations in controls with small differences. The strongest correlations in both groups were found between different attention variables: d2_CON with d2_C, d2_O with d_2TR, and d2_CON with d2_TA. The most central variables were d2_TA, d2_C, and d2_CON (highest strength centrality in both groups) and anxiety levels and pain hypervigilance (highest harmonic centrality in FMS women). The strength centrality of the network was stable for women with FMS (CScor0.7: 0.68) but not for healthy women (CScor0.7: 0.28). This study found that attention variables are most relevant within a neurocognitive network and that psychological variables are most important for the treatment of women with FMS. The clinical implications of the current findings, such as the development of treatments targeting these variables, are discussed.

Chronic pain is specifically associated with updating working memory: a longitudinal twin study

ABSTRACT

Worse executive function (EF) is associated with chronic pain and could mechanistically contribute to pain chronification. It is unclear whether there is overall impairment in EFs or whether there are impairments in specific cognitive domains. Furthermore, the possible genetic risk underlying these associations has not been tested. Participants were from the Colorado Longitudinal Twin study; 786 same-sex twins completed a battery of EF tasks at ages 23 and/or 28 and 634 of these twins self-reported chronic pain at mean age = 28.1; prevalence = 27.76% using the Brief Pain History Questionnaire. The EF tasks were used to define a Common EF factor and 2 factors specific to updating working memory and shifting mental set. We estimated the phenotypic and genetic associations of stable EF variance across ages 23 and 28, as well as EF variance unique to age 28, with pain. With respect to stable EF variance, pain phenotypically correlated with the Updating-specific factor (r = -0.21, P = 0.008) but did not significantly correlate with the Common EF factor (r = -0.06, P = 0.350) nor with the Shifting-specific factor (r = -0.03, P = 0.709). There were no significant phenotypic correlations between pain and EF variance unique to age 28. A twin model indicated that pain and Updating-specific variance share genetic risk (rA = -0.46, P = 0.005) but not environmental risk (rE = 0.05, P = 0.844). Updating working memory shares a phenotypic and genetic relationship with pain in young adults. Impairments in gating or monitoring pain signals may play a mechanistic role in pain development.

The moderating role of catastrophizing in day-to-day dynamic stress and depressive symptoms

The way individuals handle daily stressors can significantly influence their mental health. Those who struggle with emotion regulation are especially vulnerable to the negative effects of stress. This study explored the role of catastrophizing, a maladaptive emotion regulation strategy, in shaping the relationships between daily stress responses and depressive symptoms. A total of 75 healthy college students participated in the study. We adopted an Ecological Momentary Assessment protocol over 14 consecutive days to capture the day-to-day dynamics of stress reactivity and recovery. Our findings indicate that individuals with higher levels of catastrophizing exhibited increased daily stress reactivity and delayed daily stress recovery, consequently raising their likelihood of experiencing amplified depressive symptoms. In contrast, those with lower levels of catastrophizing did not experience the same negative effects of increased daily stress reactivity on their mental health. These results enhance understanding of how real-life stressors contribute to the development of mental health issues and underscore the importance of adaptive emotion regulation for improved overall health and well-being.

Longitudinal neurocognitive effects of nonmyeloablative hematopoietic stem cell transplant among older adolescents and adults with sickle cell disease: A description and comparison with sibling donors

Sickle cell disease (SCD) is associated with increased risk of neurocognitive deficits. However, whether functioning changes following nonmyeloablative hematopoietic stem cell transplant (HSCT) remains unclear. This study aimed to examine changes in neuropsychological functioning pre- to post-transplant among patients with SCD and compare patients and siblings. Adults with SCD (n = 47; Mage = 31.8 ± 8.9) and their sibling stem cell donors (n = 22; Mage = 30.5± 9.2) enrolled on a nonmyeloablative HCST protocol completed cognitive and patient-reported outcome assessments at baseline and 12 months post-transplant. Path analyses were used to assess associations between pre-transplant variables and sibling/patient group status and post-transplant function. Mean patient cognitive scores were average at both timepoints. Patient processing speed and somatic complaints improved from baseline to follow-up. Baseline performance predicted follow-up performance across cognitive variables; patient/sibling status predicted follow-up performance on some processing speed measures. Results suggest that patients with SCD demonstrate slower processing speed than siblings. Processing speed increased pre- to post-HSCT among patients and siblings, and on some measures patients demonstrated greater improvement. Thus, HSCT may improve processing speed in patients, although further confirmation is needed. Findings provide promising evidence that neurocognitive functioning remains stable without detrimental effects from pre- to 12-months post nonmyeloablative HSCT in individuals with SCD.

Pathological claustrum activity drives aberrant cognitive network processing in human chronic pain

Aberrant cognitive network activity and cognitive deficits are established features of chronic pain. However, the nature of cognitive network alterations associated with chronic pain and their underlying mechanisms require elucidation. Here, we report that the claustrum, a subcortical nucleus implicated in cognitive network modulation, is activated by acute painful stimulation and pain-predictive cues in healthy participants. Moreover, we discover pathological activity of the claustrum and a region near the posterior inferior frontal sulcus of the right dorsolateral prefrontal cortex (piDLPFC) in migraine patients during acute pain and cognitive task performance. Dynamic causal modeling suggests a directional influence of the claustrum on activity in this piDLPFC region, and diffusion weighted imaging verifies their structural connectivity. These findings advance understanding of claustrum function during acute pain and provide evidence of a possible circuit mechanism driving cognitive impairments in chronic pain.

Emotion regulation skills-focused interventions for chronic pain: A systematic review and meta-analysis

OBJECTIVES

To investigate the effect of emotion regulation skills-focused (ERSF) interventions to reduce pain intensity and improve psychological outcomes for people with chronic pain and to narratively report on safety and intervention compliance.

METHODS

Six databases and four registries were searched for randomized controlled trials (RCTs) up to 29 April 2022. Risk of bias was evaluated using the Cochrane RoB 2.0 tool, and certainty of evidence was assessed according to the Grading, Assessment, Development and Evaluation (GRADE). Meta-analyses for eight studies (902 participants) assessed pain intensity (primary outcome), emotion regulation, affect, symptoms of depression and anxiety, and pain interference (secondary outcomes), at two time points when available, post-intervention (closest to intervention end) and follow-up (the first measurement after the post-intervention assessment).

RESULTS

Compared to TAU, pain intensity improved post-intervention (weighted mean difference [WMD] = -10.86; 95% confidence interval [CI] [-17.55, -2.56]) and at follow-up (WMD = -11.38; 95% CI [-13.55, -9.21]). Emotion regulation improved post-intervention (standard mean difference [SMD] = 0.57; 95% CI [0.14, 1.01]), and depressive symptoms improved at follow-up (SMD = -0.45; 95% CI [-0.66, -0.24]). Compared to active comparators, anxiety symptoms improved favouring the comparator post-intervention (SMD = 0.10; 95% CI [0.03, 0.18]), and compared to CBT, pain interference improved post-intervention (SMD = -0.37; 95% CI [-0.69, -0.04]). Certainty of evidence ranged from very low to moderate.

SIGNIFICANCE

The findings provide evidence that ERSF interventions reduce pain intensity for people with chronic pain compared to usual treatment. These interventions are at least as beneficial to reduce pain intensity as the current gold standard psychological intervention, CBT. However, the limited number of studies and certainty of evidence mean further high-quality RCTs are warranted. Additionally, further research is needed to identify whether ERSF interventions may be more beneficial for specific chronic pain conditions.

Estimation of cognitive impairment in chronic pain patients and characteristics of estimated mild cognitive impairment

Background

Patients with chronic pain suffer from psychological effects such as anxiety due to the pain itself. Pain can not only impair activities of daily living (ADL) and quality of life (QOL), but also impair cognitive function. Therefore, in this study, we aimed to estimate the cognitive function of chronic pain patients using a deep neural network (DNN) model that has already been implemented in society. We investigated the characteristics of patients presumed to have mild cognitive impairment (MCI) and, at the same time, verified the relationship with the questionnaire commonly used in chronic pain research, which is administered by 43 university affiliated hospitals and medical institutions participating in the chronic pain research group of the Ministry of Health, Labor and Welfare in Japan (assessment batteries).

Method

The study included 114 outpatients from a multidisciplinary pain clinic, and we estimated their Mini-Mental State Examination (MMSE) scores based on age and basic blood test data (23 items). Furthermore, we classified the estimated MMSE scores of chronic pain patients into two groups based on a cutoff score of 27, which indicates MCI, and compared the blood data and assessment batteries. Additionally, we used a control group of 252 healthy adults aged 45 years or older who visited a dementia prevention outpatient clinic for comparison with the MMSE scores of chronic pain patients.

Result

The MMSE scores in chronic pain patients were below the cutoff for MCI. When classified into two groups based on the estimated MMSE score of 27 points, WBC, RBC, Hb, Hct, PLT, UA, BUN, creatinine, Triglyceride, and γ-GT were significantly higher in the blood data. In the MCI group, PDAS values were significantly lower. Furthermore, only in the non-MCI group, a significant correlation was found between the estimated MMSE value and BPI, PDAS, and Locomo. The estimated MMSE scores were significantly lower in chronic pain patients than in healthy adults (p = 0.04).

Conclusion

Patients with chronic pain may exhibit cognitive impairment due to systemic metabolic disturbances. This suggests that chronic pain affects activities of daily living, resulting in systemic metabolic disorders.

Sex and Sleep Disruption as Contributing Factors in Alzheimer's Disease

Alzheimer's disease (AD) affects more women than men, with women throughout the menopausal transition potentially being the most under researched and at-risk group. Sleep disruptions, which are an established risk factor for AD, increase in prevalence with normal aging and are exacerbated in women during menopause. Sex differences showing more disrupted sleep patterns and increased AD pathology in women and female animal models have been established in literature, with much emphasis placed on loss of circulating gonadal hormones with age. Interestingly, increases in gonadotropins such as follicle stimulating hormone are emerging to be a major contributor to AD pathogenesis and may also play a role in sleep disruption, perhaps in combination with other lesser studied hormones. Several sleep influencing regions of the brain appear to be affected early in AD progression and some may exhibit sexual dimorphisms that may contribute to increased sleep disruptions in women with age. Additionally, some of the most common sleep disorders, as well as multiple health conditions that impair sleep quality, are more prevalent and more severe in women. These conditions are often comorbid with AD and have bi-directional relationships that contribute synergistically to cognitive decline and neuropathology. The association during aging of increased sleep disruption and sleep disorders, dramatic hormonal changes during and after menopause, and increased AD pathology may be interacting and contributing factors that lead to the increased number of women living with AD.

Chronic pain accelerates cognitive impairment by reducing hippocampal neurogenesis may via CCL2/CCR2 signaling in APP/PS1 mice

Patients with chronic pain often have cognitive impairment; this is especially true in elderly patients with neurodegenerative diseases such as Alzheimer's disease (AD), but the mechanism underlying this association remains unclear. This was addressed in the present study by investigating the effect of chronic neuropathic pain on hippocampal neurogenesis and cognitive impairment using amyloid precursor protein/presenilin 1 (APP/PS1) double transgenic mice subjected to spared-nerve injury (SNI). The Von Frey test was performed to determine the mechanical threshold of mouse hind limbs after SNI. The Morris water maze test was used to evaluate spatial learning and memory. Doublecortin-positive (DCX+), 5-bromo-2'-deoxyuridine (BrdU)+, BrdU+/neuronal nuclei (NeuN)+, and C-C motif chemokine ligand 2 (CCL2)+ neurons in the dentate gyrus of the hippocampus were detected by immunohistochemistry and immunofluorescence analysis. CCL2 and C-C chemokine receptor type 2 (CCR2) protein levels in the mouse hippocampus were analyzed by western blotting. The results showed that APP/PS1 mice with chronic neuropathic pain induced by SNI had significant learning and memory impairment. This was accompanied by increased CCL2 and CCR2 expression and decreases in the number of DCX+, BrdU+, and BrdU+/NeuN+ neurons. These results suggest that chronic neuropathic pain is associated with cognitive impairment, which may be caused by CCL2/CCR2 signaling-mediated inhibition of hippocampal neurogenesis. Thus, therapeutic strategies that alleviate neuropathic pain can potentially slow cognitive decline in patients with AD and other neurodegenerative diseases.

Pathological claustrum activity drives aberrant cognitive network processing in human chronic pain

Aberrant cognitive network activity and cognitive deficits are established features of chronic pain. However, the nature of cognitive network alterations associated with chronic pain and their underlying mechanisms require elucidation. Here, we report that the claustrum, a subcortical nucleus implicated in cognitive network modulation, is activated by acute painful stimulation and pain-predictive cues in healthy participants. Moreover, we discover pathological activity of the claustrum and a lateral aspect of the right dorsolateral prefrontal cortex (latDLPFC) in migraine patients. Dynamic causal modeling suggests a directional influence of the claustrum on activity in this latDLPFC region, and diffusion weighted imaging (DWI) verifies their structural connectivity. These findings advance understanding of claustrum function during acute pain and provide evidence of a possible circuit mechanism driving cognitive impairments in chronic pain.

Determination of cognitive status and influencing variables in patients with chronic neck pain: A cross-sectional study

OBJECTIVES

This study aimed to evaluate cognitive function in individuals with chronic neck pain (CNP) and investigate the effects of different variables on cognition.

METHODS

The sociodemographic characteristics of the individuals who participated in this study were recorded. Pain intensity of the individuals was evaluated using the Visual Analog Scale, pain-related disability was evaluated with the Neck Disability Index and cognitive function was evaluated using Montreal Cognitive Assessment (MoCA).

RESULTS

For this study, 95 patients with CNP were recruited. The mean age was 45.61 ± 11.14, and the median MoCA score was 24 (20-26), and 64.2% of the patients scored below the original cutoff (<26/30 points). The regression analysis showed that higher age and lower education levels were associated with lower MoCA scores. Education appeared to be the most influential variable. Younger participants (18-45) performed systematically better on naming, attention and language domains than their older counterparts (over 45).

CONCLUSIONS

The findings suggest that age and education play an important role in MoCA total and domain scores in these patients. While treating these patients, assessment of cognitive function can be useful for effective pain management.

The Relationship Between Chronic Pain and Cognitive Impairment in the Elderly: A Review of Current Evidence

Chronic pain and cognitive impairment are prevalent geriatric syndromes in the population of older adults, and they are the main cause of disability in people over sixty-five years of age. As the global population continues to age, chronic pain and cognitive impairment will affect an increasing number of older adults. While numerous studies in recent years have shown that chronic pain is associated with cognitive decline, the exact mechanisms linking the two remain unclear. In this review, we aim to present the available evidence on the connection between chronic pain and cognitive impairment and to discuss the potential mechanisms by which chronic pain affects cognitive function. In addition, we review potential therapeutic interventions targeting psychological factors, microglia activation, and altered gut flora that may improve and prevent cognitive decline in people with chronic pain.

Cerebrolysin Attenuates Exacerbation of Neuropathic Pain, Blood-spinal Cord Barrier Breakdown and Cord Pathology Following Chronic Intoxication of Engineered Ag, Cu or Al (50-60 nm) Nanoparticles

Neuropathic pain is associated with abnormal sensations and/or pain induced by non-painful stimuli, i.e., allodynia causing burning or cold sensation, pinching of pins and needles like feeling, numbness, aching or itching. However, no suitable therapy exists to treat these pain syndromes. Our laboratory explored novel potential therapeutic strategies using a suitable composition of neurotrophic factors and active peptide fragments-Cerebrolysin (Ever Neuro Pharma, Austria) in alleviating neuropathic pain induced spinal cord pathology in a rat model. Neuropathic pain was produced by constrictions of L-5 spinal sensory nerves for 2-10 weeks period. In one group of rats cerebrolysin (2.5 or 5 ml/kg, i.v.) was administered once daily after 2 weeks until sacrifice (4, 8 and 10 weeks). Ag, Cu and Al NPs (50 mg/kg, i.p.) were delivered once daily for 1 week. Pain assessment using mechanical (Von Frey) or thermal (Hot-Plate) nociceptive showed hyperalgesia from 2 weeks until 10 weeks progressively that was exacerbated following Ag, Cu and Al NPs intoxication in nerve lesioned groups. Leakage of Evans blue and radioiodine across the blood-spinal cord barrier (BSCB) is seen from 4 to 10 weeks in the rostral and caudal cord segments associated with edema formation and cell injury. Immunohistochemistry of albumin and GFAP exhibited a close parallelism with BSCB leakage that was aggravated by NPs following nerve lesion. Light microscopy using Nissl stain exhibited profound neuronal damages in the cord. Transmission electron microcopy (TEM) show myelin vesiculation and synaptic damages in the cord that were exacerbated following NPs intoxication. Using ELISA spinal tissue exhibited increased albumin, glial fibrillary acidic protein (GFAP), myelin basic protein (MBP) and heat shock protein (HSP 72kD) upregulation together with cytokines TNF-α, IL-4, IL-6, IL-10 levels in nerve lesion that was exacerbated following NPs intoxication. Cerebrolysin treatment significantly reduced hyperalgesia and attenuated BSCB disruption, edema formation and cellular changes in nerve lesioned group. The levels of cytokines were also restored near normal levels with cerebrolysin treatment. Albumin, GFAP, MABP and HSP were also reduced in cerebrolysin treated group and thwarted neuronal damages, myelin vesiculation and cell injuries. These neuroprotective effects of cerebrolysin with higher doses were also effective in nerve lesioned rats with NPs intoxication. These observations suggest that cerebrolysin actively protects spinal cord pathology and hyperalgesia following nerve lesion and its exacerbation with metal NPs, not reported earlier.

Neurocognitive predictors of adherence to an online pain self-management program adjunct to long-term opioid therapy

INTRODUCTION

While pain self-management programs can significantly improve patient outcomes, poor adherence is common and the need for research on predictors of adherence has been noted. A potential, but commonly overlooked, predictor is cognitive function. Our aim, then, was to examine the relative influence of various cognitive functional domains on engagement with an online pain self-management program.

METHOD

A secondary analysis of a randomized controlled trial testing the impact of E-health (a 4-month subscription to the online Goalistics Chronic Pain Management Program) plus treatment as usual, relative to treatment as usual alone, on pain and opioid dose outcomes in adults receiving long-term opioid therapy of morphine equivalence dose ≥20 mg; 165 E-health participants who completed an on-line neurocognitive battery were included in this sub-analysis. A variety of demographic, clinical, and symptom rating scales were also examined. We hypothesized that better processing speed and executive functions at baseline would predict engagement with the 4-month E-health subscription.

RESULTS

Ten functional cognitive domains were identified using exploratory factor analysis and the resultant factor scores applied for hypothesis testing. The strongest predictors of E-health engagement were selective attention, and response inhibition and speed domains. An explainable machine learning algorithm improved classification accuracy, sensitivity, and specificity.

CONCLUSIONS

The results suggest that cognition, especially selective attention, inhibitory control, and processing speed, is predictive of online chronic pain self-management program engagement. Future research to replicate and extend these findings seems warranted.

CLINICALTRIALS.GOV REGISTRATION NUMBER

NCT03309188.

Altered social decision making in patients with chronic pain

BACKGROUND

Chronic pain affects up to 20% of the population, impairs quality of life and reduces social participation. Previous research reported that pain-related perceived injustice covaries with these negative consequences. The current study probed whether chronic pain patients responded more strongly to disadvantageous social inequity than healthy individuals.

METHODS

We administered the Ultimatum Game, a neuroeconomic social exchange game, where a sum of money is split between two players to a large sample of patients with chronic pain disorder with somatic and psychological factors (n = 102) and healthy controls (n = 101). Anonymised, and in truth experimentally controlled, co-players proposed a split, and our participants either accepted or rejected these offers.

RESULTS

Chronic pain patients were hypersensitive to disadvantageous inequity and punished their co-players for proposed unequal splits more often than healthy controls. Furthermore, this systematic shift in social decision making was independent of patients' performance on tests of executive functions and risk-sensitive (non-social) decision making .

CONCLUSIONS

Our findings indicate that chronic pain is associated with anomalies in social decision making (compared to healthy controls) and hypersensitivity to social inequity that is likely to negatively impact social partaking and thereby the quality of life.

Can high pain intensity and catastrophizing interfere with the cognitive performance of women with chronic pain related TMD? A cross-sectional study

OBJECTIVE

Interventions based on pain education and self-management are dependent on factors such as attention, memory, concentration, and executive function. To explore the relationship between cognitive performance and the variables pain intensity, central sensitization, catastrophizing, and hypervigilance in women diagnosed with chronic pain-related TMD.

METHODOLOGY

This is a cross-sectional study. A total of 33 women (mean age: 38±4.6 years; range: 18 to 66 years) with chronic pain-related TMD (myalgia and/or arthralgia) diagnosed according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD). Specific questionnaires were used to evaluate cognitive performance, overall pain intensity, central sensitization, hypervigilance, and pain catastrophizing. The data were analyzed using Pearson's correlation coefficient and backward stepwise multiple linear regression (statistical significance at 5% alpha).

RESULTS

Approximately 53% of the study sample showed decreased cognitive performance. High central sensitization, hypervigilance, and pain catastrophizing were observed. A significant negative correlation was observed between cognitive performance and hypervigilance (p=.003, r=-.49), cognitive performance and catastrophizing (p<.001, r=-.58), and cognitive performance and pain intensity (p<.001, r=-.58). Regarding the partial regression coefficients, only catastrophizing and pain intensity showed statistical significance (t=-2.12, p=.043; t=-2.64, p=.014, respectively), indicating a significant role in explaining cognitive performance at the sample.

CONCLUSION

High pain intensity and the presence of catastrophic thoughts regarding pain can predict impaired cognitive performance in women with chronic pain-related TMD. Management strategies addressing psychosocial dimensions such as reducing catastrophizing and ensuring complete understanding of the condition are important.

The effect of executive function on the development of chronic pain: A prospective longitudinal study

Increasing evidence suggests a close association between chronic pain and executive function, a set of cognitive processes necessary for goal-directed behaviors. However, there is a dearth of longitudinal studies examining the predictive effect of executive function on the development of chronic pain. Drawing on the cyclical model of executive function and health, we sought to examine how executive function, measured at baseline, may predict chronic pain etiology approximately 9 years later. Using a large-scale dataset of midlife adults (N = 1553) from the MIDUS 2 and 3 (Midlife Development in the United States) studies, we employed multivariate logistic regression to examine the etiology of new chronic pain for individuals who did not have chronic pain at baseline. Further, we also tested whether executive function predicted the degree of pain interference, among individuals with chronic pain. Our results revealed that lower baseline executive function was associated with a significant likelihood of developing chronic pain 9 years later (OR = 0.812, p = .001), even after adjusting for demographics, health, and psychosocial confounds (OR = 0.827, p = .014). However, executive function failed to robustly predict the etiology and degree of chronic pain interference. Our findings underscore the critical role of executive function on the development of chronic pain.

Evaluation of emotion-centric psychological interventions for chronic pain: protocol for a systematic review and meta-analysis

INTRODUCTION

Chronic pain, defined as pain persisting longer than 3 months, is more than an unpleasant sensory experience. Persistent negative emotions and emotional comorbidities, such as depression and anxiety, plague people with chronic pain leading to worsening pain intensity and increasing disability. While cognitive-behavioural therapy (CBT) is the gold standard psychological treatment, recent evidence highlights that CBT lacks efficacy for the physical and emotional aspects of chronic pain. Increasingly, researchers are investigating emotion-centric psychological therapies. While treatment modalities vary, these interventions frequently target understanding emotions, and train individuals for an emotionally adaptive response. The aim of this systematic review and meta-analysis is to quantify the efficacy of emotion-centric interventions for the physical and emotional characteristics of chronic pain.

METHODS/ANALYSIS

Electronic databases (EMBASE, PubMed, PsychINFO, Cochrane Central Register of Controlled Trials, CINAHL and Web of Science) will be systematically searched from inception to 28 April 2022 for randomised controlled trials. Studies that compare an emotion-centric intervention with another form of treatment or placebo/control for adults (≥18 years old) with chronic pain will be included. All treatment modes (eg, online or in-person), any duration and group-based or individual treatments will be included. Studies that do not investigate at least one emotion-centric treatment will be excluded. The primary outcome is pain intensity. Secondary outcomes include emotion dysregulation, depression, anxiety, affect, safety and intervention compliance. A quantitative synthesis using a random effects meta-analysis will be adopted. Risk of bias will be evaluated using Cochrane Risk of Bias V.2.0 with the certainty of evidence assessed according to Recommendation, Assessment, Development and Evaluation. Data permitting, subgroup analysis will be conducted for intervention type and pain condition.

ETHICS AND DISSEMINATION

Ethical approval is not required for this systematic review. Results may inform an efficacy study examining a new emotion-centric intervention for chronic pain. Dissemination will be through peer-reviewed publications and in conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42021266815.

Sensory discrimination training for adults with chronic musculoskeletal pain: a systematic review

BACKGROUND

Sensory discrimination training (SDT) is a form of feedback guided sensory training used in the treatment of chronic musculoskeletal pain (CMP).

OBJECTIVE

This systematic review aimed to investigate the efficacy and safety of SDT for CMP.

METHODS

MEDLINE, CINAHL, EMBASE, AMED, CENTRAL, PsycINFO, Scopus, OT Seeker, PEDro, ETHOS, Web of Science, and Open Grey were searched for appropriate randomized controlled trials (RCTs). Included papers were assessed for risk of bias, and evidence was graded using the GRADE approach. The protocol was published on PROSPERO (anonymized).

RESULTS

Ten RCTs met the inclusion/exclusion criteria. There was conflicting evidence from seven RCTs for the efficacy of SDT for chronic low back pain (CLBP). There was very low-quality evidence from two studies supporting the efficacy of SDT for phantom limb pain (PLP). There was very low-quality evidence from one RCT for the efficacy of SDT for Fibromyalgia. No adverse effects of SDT were identified.

CONCLUSIONS

SDT has been delivered in multiple forms in the literature. SDT does not appear to be associated with any adverse effects and shows potential regarding its clinical efficacy. However, there is a lack of high-quality evidence upon which to make any firm clinical recommendations.

Pain, Opioid Analgesics, and Cognition: A Conceptual Framework in Older Adults

Chronic pain is highly prevalent in older adults and is associated with poor functional outcomes. Furthermore, opioid analgesics are commonly utilized for the treatment of pain in older adults despite well-described adverse effects. Importantly, both chronic pain and opioid analgesics have been linked with impairments in cognitive function, though data are limited. In this manuscript we summarize the evidence and critical knowledge gaps regarding the relationships between pain, opioid analgesics, and cognition in older adults. Furthermore, we provide a conceptual framework to guide future research in the development, implementation, and evaluation of strategies to optimize analgesic outcomes in older adults while minimizing deleterious effects on cognition.

Comparing Perceived Pain Impact Between Younger and Older Adults With High Impact Chronic Pain: A Cross-Sectional Qualitative and Quantitative Survey

High impact chronic pain (HICP) is a recently proposed concept for treatment stratifying patients with chronic pain and monitoring their progress. The goal is to reduce the impact of chronic pain on the individual, their family, and society. The US National Pain Strategy defined HICP as the chronic pain associated with substantial restrictions on participation in work, social, and self-care activities for at least 6 months. To understand the meaning and characteristics of HICP from the younger (<65 years old) and older adults (≥65 years old) with chronic pain, our study examined patients' perceived pain impact between the two age groups. We also characterize the degree of pain impact, assessed with the Patient-Reported Outcomes Measurement Information System (PROMIS) pain interference (PI), between adults and older adults with HICP. We recruited patients at a tertiary pain clinic. The survey included open-ended questions about pain impact, the Graded Chronic Pain Scale-Revised to identify patients' meeting criteria for HICP, and the Patient-Reported Outcomes Measurement Information System (PROMIS^®) 8-item PI short form (v.8a). A total of 55 younger adults (65.5% women, 72.7% HICP, mean age = 55.0 with SD of 16.2) and 28 older adults (53.6% women, 64.3% HICP, mean age = 72.6 with SD of 5.4) with chronic pain participated in this study. In response to an open-ended question in which participants were asked to list out the areas of major impact pain, those with HICP in the younger group most commonly listed work, social activity, and basic physical activity (e.g., walking and standing); for those in the older group, basic physical activity, instrumental activity of daily living (e.g., housework, grocery shopping), and participating in social or fun activity for older adults with HICP were the most common. A 2 × 2 ANOVA was conducted using age (younger adults vs. older adults) and HICP classification (HICP vs. No HICP). A statistically significant difference was found in the PROMIS-PI T-scores by HICP status (HICP: M = 58.4, SD = 6.3; No HICP: M = 67.8, SD = 6.3), but not by age groups with HICP. In conclusion, perceived pain impacts were qualitatively, but not quantitatively different between younger and older adults with HICP. We discuss limitations and offer recommendations for future research.

Differential Rearrangement of Excitatory Inputs to the Medial Prefrontal Cortex in Chronic Pain Models

Chronic pain patients suffer a disrupted quality of life not only from the experience of pain itself, but also from comorbid symptoms such as depression, anxiety, cognitive impairment, and sleep disturbances. The heterogeneity of these symptoms support the idea of a major involvement of the cerebral cortex in the chronic pain condition. Accordingly, abundant evidence shows that in chronic pain the activity of the medial prefrontal cortex (mPFC), a brain region that is critical for executive function and working memory, is severely impaired. Excitability of the mPFC depends on the integrated effects of intrinsic excitability and excitatory and inhibitory inputs. The main extracortical sources of excitatory input to the mPFC originate in the thalamus, hippocampus, and amygdala, which allow the mPFC to integrate multiple information streams necessary for cognitive control of pain including sensory information, context, and emotional salience. Recent techniques, such as optogenetic methods of circuit dissection, have made it possible to tease apart the contributions of individual circuit components. Here we review the synaptic properties of these main glutamatergic inputs to the rodent mPFC, how each is altered in animal models of chronic pain, and how these alterations contribute to pain-associated mPFC deactivation. By understanding the contributions of these individual circuit components, we strive to understand the broad spectrum of chronic pain and comorbid pathologies, how they are generated, and how they might be alleviated.

NAAA-regulated lipid signaling governs the transition from acute to chronic pain

Chronic pain affects 1.5 billion people worldwide but remains woefully undertreated. Understanding the molecular events leading to its emergence is necessary to discover disease-modifying therapies. Here we show that N-acylethanolamine acid amidase (NAAA) is a critical control point in the progression to pain chronicity, which can be effectively targeted by small-molecule therapeutics that inhibit this enzyme. NAAA catalyzes the deactivating hydrolysis of palmitoylethanolamide, a lipid-derived agonist of the transcriptional regulator of cellular metabolism, peroxisome proliferator-activated receptor-α (PPAR-α). Our results show that disabling NAAA in spinal cord during a 72-h time window following peripheral tissue injury halts chronic pain development in male and female mice by triggering a PPAR-α-dependent reprogramming of local core metabolism from aerobic glycolysis, which is transiently enhanced after end-organ damage, to mitochondrial respiration. The results identify NAAA as a crucial control node in the transition to chronic pain and a molecular target for disease-modifying medicines.

The No Worries Trial: Efficacy of Online Dialectical Behaviour Therapy Skills Training for Chronic Pain (iDBT-Pain) Using A Single Case Experimental Design

Emotion dysregulation frequently co-occurs with chronic pain, which in turn leads to heightened emotional and physical suffering. This cycle of association has prompted a recommendation for psychological treatment of chronic pain to target mechanisms for emotion regulation. The current trial addressed this need by investigating a new internet-delivered treatment incorporating emotional skills training from dialectical behavioural therapy (DBT). Using a single-case experimental design that is suited to heterogeneous populations and can demonstrate efficacy with a small sample, three participants with chronic pain were recruited. Participants received four weeks of online DBT skills training (iDBT-Pain intervention) which incorporated one-on-one sessions over Zoom and a web app. Results revealed compelling evidence for the intervention on the primary outcome of emotion dysregulation and were promising for the secondary outcome of pain intensity. Improvement was also identified on pre-and post-measures of depression, coping behaviours, sleep problems, wellbeing, and harm avoidance, indicating that the intervention may positively influence other factors related to chronic pain. Overall, the trial provides preliminary efficacy for the intervention to improve chronic pain. However, we recommend further investigation of the iDBT-Pain intervention, either in single case trials, which when conducted with scientific rigour may be aggregated to derive nomothetic conclusions, or in a group-comparison trial to compare with usual modes of treatment. Perspective: This trial advances understanding of emotion-focused treatment for chronic pain and provides evidence for a viable new technological treatment. Importantly, as an internet-delivered approach, the iDBT-Pain intervention is accessible to those with restricted mobility and remote communities where there are often limited psychological services for people with chronic pain. Trial registration: The trial was registered on the Australian and New Zealand Clinical Trials Registry (ACTRN12620000604909).

Brain changes associated with impaired attention function in chronic pain

Attention function is thought to be important in chronic pain, with the pathology of chronic pain closely associated with cognitive-emotional components. However, there have been few neuroimaging studies of the relationship between attention function and chronic pain. We used the method of functional connectivity analysis for resting-state fMRI (rs-fMRI) data and the Attention Network Test-Revision (ANT-R) to clarify the attention-related pathology of chronic pain. We performed rs-fMRI and ANT-R on a group of 26 chronic pain (somatoform pain disorder) patients and 28 age-matched healthy controls. A significant group difference in validity effects, a component of ANT-R, emerged (F_1,46 = 5.91, p = 0.019), and the chronic pain group exhibited slower reaction times. Decreased brain connectivity of the left insula and left frontal regions was confirmed in chronic pain patients (p^FWE < 0.05), and connectivity was negatively correlated with validity effects (r = -0.29, permutation test p = 0.033). Further, decreased functional connectivity strength of the right insula and left temporal gyrus in the chronic pain group were confirmed (p^FWE < 0.05). We conclude that poor control of attention function results from deficits of functional connectivity in the left insula and left frontal regions in chronic pain.

Examining the effect of stress induction on auditory working memory performance for emotional and non-emotional stimuli in female students

Background

Theoretical frameworks have shown that stress might influence working memory in different ways. Previous research has investigated the effect of stress on female's working memory but there is lack of evidence regarding the impact of emotional aspects.

Objectives

This study examined the effect of stress induction on auditory working memory (AWM) performance among university students for emotional (positive and negative) and non-emotional (neutral) stimuli.

Methods

A sample of 102 female students at the Universities of Isfahan, Iran was selected using convenience sampling in 2018. Participants completed the demographic information sheets, then, they were randomly assigned into the experimental and control groups. The stress was induced by the Socially Evaluated Cold Pressor Test (SECPT). An n-back task was presented pre and post of stress induction, to evaluate the AWM performance (accuracy and reaction time). The research data were analyzed using mixed-model ANOVA.

Results

Both accuracy and reaction time (RT) scores were found to be enhanced for positive words in the experimental condition. However, accuracy and RT indices were found to be worsening for negative words in the experimental condition.

Conclusions

This study supports the idea that stress influences AWM performance depend on emotionally-valenced stimuli, which may help us to better understand the underlying mechanisms of memory processing.

Pain Catastrophizing Mediates and Moderates the Link Between Acute Pain and Working Memory

The bidirectional relationship between pain and working memory (WM) deficits is well-documented but poorly understood. Pain catastrophizing-exaggerated, negative cognitive and emotional responses toward pain-may contribute to WM deficits by occupying finite, shared cognitive resources. The present study assessed the role of pain catastrophizing as both a state-level process and trait-level disposition in the link between acute pain and WM. Healthy, young adults were randomized to an experimentally-induced ischemic pain or control task, during which they completed verbal and non-verbal WM tests. Participants also completed measures of state- and trait-level pain catastrophizing. Simple mediation analyses indicated that participants in the pain group (vs. control) engaged in more state-level catastrophizing about pain, which led to worse verbal and non-verbal WM. Moderated mediation analyses indicated that the indirect (mediation) effect of state-level pain catastrophizing was moderated by trait-level pain catastrophizing for both verbal and non-verbal WM. Participants in the pain group who reported a greater trait-level tendency to catastrophize about pain experienced greater state-level catastrophizing about pain during the ischemic task, which led to worse verbal and non-verbal WM performance. These results provide evidence for pain catastrophizing as an important mechanism and moderating factor of WM deficits in acute pain. Future research should replicate these results in chronic pain samples, investigate other potential mechanisms (e.g., sleep disturbances), and determine if interventions that target pain catastrophizing directly can ameliorate cognitive deficits in people with pain. PERSPECTIVE: This article presents a laboratory study examining the relationships among pain, pain catastrophizing, and working memory in healthy participants. The results shed new light on these relationships and raise the possibility that interventions that reduce catastrophizing may lead to improved cognitive function among people with pain.

dmPFC-vlPAG projection neurons contribute to pain threshold maintenance and antianxiety behaviors

The dorsal medial prefrontal cortex (dmPFC) has been recognized as a key cortical area for nociceptive modulation. However, the underlying neural pathway and the function of specific cell types remain largely unclear. Here, we show that lesions in the dmPFC induced an algesic and anxious state. Using multiple tracing methods including a rabies-based transsynaptic tracing method, we outlined an excitatory descending neural pathway from the dmPFC to the ventrolateral periaqueductal gray (vlPAG). Specific activation of the dmPFC/vlPAG neural pathway by optogenetic manipulation produced analgesic and antianxiety effects in a mouse model of chronic pain. Inhibitory neurons in the dmPFC were specifically activated using a chemogenetic approach, which logically produced an algesic and anxious state under both normal and chronic pain conditions. Antagonists of the GABAA receptor (GABAAR) or mGluR1 were applied to the dmPFC, which produced analgesic and antianxiety effects. In summary, the results of our study suggest that the dmPFC/vlPAG neural pathway might participate in the maintenance of pain thresholds and antianxiety behaviors under normal conditions, while silencing or suppressing the dmPFC/vlPAG pathway might be involved in the initial stages and maintenance of chronic pain and the emergence of anxiety-like behaviors.

Modeling neural and self-reported factors of affective distress in the relationship between pain and working memory in healthy individuals

The relationship between pain and cognition has primarily been investigated in patients with chronic pain and healthy participants undergoing experimental pain. Recently, there has been interest in understanding the disruptive effects of non-experimental pain in otherwise healthy individuals. Recent studies suggest that healthy individuals reporting pain also demonstrate decrements in working memory (WM) performance, however factors contributing to this relationship remain poorly understood. The present study examined the association between pain and WM in a large community-based sample of healthy individuals and investigated whether self-reported affective distress and medial frontal cortex activity might help to explain this relationship. To address these research questions, a large publicly available dataset from the Human Connectome Project (N = 416) was sourced and structural equation modeling was utilized to examine relationships between pain intensity experienced over the past 7 days, self-reported affective distress, performance on a WM (n-back) task, and task-related activation in the medial frontal cortex. Examining participants who reported non-zero pain intensity in the past 7 days (n = 228), we found a direct negative association between pain intensity and performance on the WM n-back task, consistent with prior findings. Self-reported affective distress was not associated with WM performance. Additionally, pain intensity was indirectly associated with WM performance via WM task-related activity in the ventromedial prefrontal cortex (vmPFC). Our findings suggest that pain experienced in everyday life by otherwise healthy individuals may directly impact WM performance. Furthermore, WM task-related increases in vmPFC activity may be a factor contributing to this relationship.

Executive Functioning in Adolescents with Chronic Musculoskeletal Pain

Adolescents with chronic pain often suffer significant impairment in physical, emotional, and social domains. Surprisingly little is known about executive functioning (EF) in youth with chronic pain or how EF deficits may contribute to functional impairment. Study participants included 60 adolescents between the ages of 12 and 17 years (M = 14.57). Thirty participants with chronic musculoskeletal pain and 30 age- and gender-matched healthy controls were recruited from a large Midwestern children's hospital in the United States. Participants completed the Behavior Rating Inventory of Executive Functioning (BRIEF-2) as well as multiple measures of functional impairment across key domains: school, social, emotional (anxiety, depression), and physical. Adolescents with chronic musculoskeletal pain reported significantly greater EF impairment compared to healthy age- and gender-matched peers. Clinically elevated risk levels of impairment were reported across all aspects of EF, with many adolescents in the chronic pain group scoring above the clinical risk cut off for working memory (52%), inhibition (45%), and cognitive flexibility (38%). EF was also significantly related to functional impairment across all domains. Findings suggest that EF may have an impact across several critical domains of functioning for youth with chronic pain.

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

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

Neurocognitive functioning in symptomatic adults with sickle cell disease: A description and comparison with unaffected siblings

Children and adults with sickle cell disease (SCD) are at risk for neuropsychological deficits; however, the neurocognitive functioning of adults with SCD and related comorbidities has not been widely reported in the literature. We examined specific cognitive domains in symptomatic adults with SCD and compared them with their unaffected siblings. We also examined relationships between cognitive scores, patient-reported outcomes (PROs), and medical/laboratory values. Thirty patient-sibling pairs (M patient age = 32.5 years, M sibling age = 32.1 years) completed evaluations as part of a medical clinical trial (NCT00061568). All patient and sibling neurocognitive test scores were within normal limits. Patients scored significantly lower (M = 91.0 ± 11.3) than their siblings (M = 100.6 ± 12.3; t = -3.5, p < .01) on the Wechsler Processing Speed Index. They also indicated more problems than siblings on an executive functioning questionnaire, although these differences were nonsignificant after accounting for depressive symptoms. Higher fetal hemoglobin and lower creatinine correlated with better scores on particular cognitive and PRO measures. In summary, our sample of adults with symptomatic SCD demonstrated worse processing speed and experience more executive challenges than their siblings, despite treatment with hydroxyurea. These relative weakness likely relate to disease processes but the specific physiological mechanism is unclear.

[Psychotherapy in the Context of Interdisciplinary Multimodal Pain Therapy: Update]

Interdisciplinary multimodal pain therapy (IMPT) is based on the biopsychosocial model of pain and describes an integrated treatment for patients with chronic pain. IMPT incorporates a close cooperation of different disciplines, including physicians, psychotherapists, physiotherapists, and others. IMPT mainly aims to restore and increase patients' physical, social and psychological functional capacity. The efficacy of IMPT has been evidenced by systematic reviews and meta-analyses. A number of studies further indicate IMPT's cost-efficiency. Psychotherapy is an essential component of IMPT. Its main goal within the framework of IMPT is to identify and modify dysfunctional patterns of pain coping, and to diagnose and potentially treat psychological comorbidities. Pain psychotherapy comprises mostly cognitive-behavioral interventions which address dysfunctional coping at the three levels of the pain experience (i.e., cognitive, emotional, and behavioral). Research into the efficacy of pain psychotherapy is rather sparse and studies have mostly focused on chronic back pain, yet existing results show promising evidence both for psychotherapy within IMPT and for psychotherapy as a monotherapy. This paper aims at providing an overview of (a) commonly employed cognitive-behavioral psychotherapeutic approaches and strategies in the treatment of chronic pain, and (b) the existing empirical evidence of pain psychotherapy both within the framework of IMPT and as a monotherapy. Future research should include a wider range of pain diagnoses and also investigate the potential benefit of individually-tailored treatments.

Altered Brain Structure and Functional Connectivity and Its Relation to Pain Perception in Girls With Irritable Bowel Syndrome

OBJECTIVE

Imaging studies in adults with irritable bowel syndrome (IBS) have shown both morphological and resting state (RS) functional connectivity (FC) alterations related to cortical modulation of sensory processing. Because analogous differences have not been adequately investigated in children, this study compared gray matter volume (GMV) and RS-FC between girls with IBS and healthy controls (HC) and tested the correlation between brain metrics and laboratory-based pain thresholds (Pth).

METHODS

Girls with Rome III criteria IBS (n = 32) and matched HCs (n = 26) were recruited. In a subset of patients, Pth were determined using a thermode to the forearm. Structural and RS scans were acquired. A voxel-based general linear model, adjusting for age, was applied to compare differences between groups. Seeds were selected from regions with group GMV differences for a seed-to-voxel whole brain RS-FC analysis. Significance for analyses was considered at p < .05 after controlling for false discovery rate. Significant group differences were correlated with Pth.

RESULTS

Girls with IBS had lower GMV in the thalamus, caudate nucleus, nucleus accumbens, anterior midcingulate (aMCC), and dorsolateral prefrontal cortex. They also exhibited lower RS-FC between the aMCC and the precuneus, but greater connectivity between the caudate nucleus and precentral gyrus. Girls with IBS had higher Pth with a moderate effect size (t(22.81) = 1.63, p = .12, d = 0.64) and lower thalamic GMV bilaterally was correlated with higher Pth (left: r = -.62, p(FDR) = .008; right: r = -.51, p(FDR) = .08).

CONCLUSIONS

Girls with IBS had lower GMV in the PFC, basal ganglia, and aMCC, as well as altered FC between multiple brain networks, suggesting that structural changes related to IBS occur early in brain development. Girls with IBS also showed altered relationships between pain sensitivity and brain structure.

Human Capital and Administrative Burden: The Role of Cognitive Resources in Citizen-State Interactions

One means by which the state reinforces inequality is by imposing administrative burdens that loom larger for citizens with lower levels of human capital. Integrating insights from various disciplines, this article focuses on one aspect of human capital: cognitive resources. The authors outline a model that explains how burdens and cognitive resources, especially executive functioning, interrelate. The article then presents illustrative examples, highlighting three common life factors-scarcity, health problems, and age-related cognitive decline. These factors create a human capital catch-22, increasing people's likelihood of needing state assistance while simultaneously undermining the cognitive resources required to negotiate the burdens they encounter while seeking such assistance. The result is to reduce access to state benefits and increase inequality. The article concludes by calling for scholars of behavioral public administration and public administration more generally to incorporate more attention to human capital into their research.

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.

The link between chronic pain and Alzheimer's disease

Chronic pain often occurs in the elderly, particularly in the patients with neurodegenerative disorders such as Alzheimer's disease (AD). Although studies indicate that chronic pain correlates with cognitive decline, it is unclear whether chronic pain accelerates AD pathogenesis. In this review, we provide evidence that supports a link between chronic pain and AD and discuss potential mechanisms underlying this connection based on currently available literature from human and animal studies. Specifically, we describe two intertwined processes, locus coeruleus noradrenergic system dysfunction and neuroinflammation resulting from microglial pro-inflammatory activation in brain areas mediating the affective component of pain and cognition that have been found to influence both chronic pain and AD. These represent a pathological overlap that likely leads chronic pain to accelerate AD pathogenesis. Further, we discuss potential therapeutic interventions targeting noradrenergic dysfunction and microglial activation that may improve patient outcomes for those with chronic pain and AD.

Insomnia-related Memory Impairment in Individuals With Very Complex Chronic Pain

OBJECTIVE

To investigate the specific effect of insomnia on neuropsychological functioning in patients with very complex chronic pain.

BACKGROUND

Individuals with insomnia disorder or chronic pain often experience cognitive deficits, with both conditions appearing to correlate with impairments in neuropsychological functions. As insomnia often occurs comorbid with chronic pain, distinguishing the differential effects of these two syndromes on an individual's neuropsychological functioning can be challenging. Comorbid depressive symptoms in these individuals, which may also affect cognitive function, may further obscure the associations between chronic pain, insomnia, and the neuropsychological profile.

METHODS

The neuropsychological function of 22 individuals with very complex chronic pain was assessed using specialized tests examining aspects of memory and executive functioning. The severity of insomnia, depression, and anxiety was measured using questionnaires, and pain levels were assessed using a visual analog scale. Pain medications were transformed to the morphine-equivalent daily dose.

RESULTS

Insomnia severity was found to predict memory function, accounting for 32.4% of the variance: A 1 SD increase in insomnia severity decreased memory function by 0.57 SD. The negative correlation between insomnia and memory was significant even after controlling for pain level, morphine-equivalent daily dose, and comorbid levels of anxiety and depression.

CONCLUSIONS

Insomnia severity independently predicted memory function in patients with very complex chronic pain, even after controlling for other factors known to impair cognitive function. Insomnia may possibly explain some of the cognitive impairments related to chronic pain; thus, screening for, and treating, sleep disturbances may be a central aspect of chronic pain rehabilitation.

Are Functional Brain Alterations Present in Low Back Pain? A Systematic Review of EEG Studies

This systematic review analyzed available literature on functional brain alterations in low back pain (LBP) measured with electroencephalography (EEG), as until now evidence thereof was unclear. Four electronic databases were systematically searched the 10th of March 2018, resulting in 12 included studies. Studies showed a risk of bias of 37.5 to 75% using the Newcastle-Ottawa Scale for case-control studies. Limited evidence reported higher amplitudes of balance-related potentials and early components of somatosensory evoked potentials (SEP) to noxious stimuli, and altered feedback-related negativity and P300 potentials during decision-making in chronic LBP (CLBP). These findings suggest postural strategies requiring a higher cortical attention-demand, increased sensory-discriminative processing of noxious input, and altered decision-making in CLBP. However, further research is warranted as these inferences were based on single studies. Moderate evidence for unaltered amplitude of late-phase SEPs to noxious stimuli and auditory evoked potentials in LBP implies that the affective-emotional processing of stimuli might be unaffected in LBP. Furthermore, moderate evidence indicated disturbed habituation of somatosensory stimuli in LBP. Most studies examined nonspecific or mixed CLBP populations, hence EEG-quantified brain activity in (sub)acute or recurrent LBP still needs to be explored. PERSPECTIVE: This review presents an overview of the current understanding of the functional LBP brain measured with EEG. The limited evidence in current research suggests altered cortical function regarding balance control, somatosensory processing, and decision making in LBP, and highlights opportunities for future EEG-research.

Caregiver Well-being and the Quality of Cancer Care

OBJECTIVES

To conceptualize the pathways and assess current evidence for the relationship between caregiver well-being and the quality of the cancer patient's care.

DATA SOURCES

Qualitative, quantitative, and theoretical literature and official reports.

CONCLUSION

Caregiver well-being has both direct and indirect effects on the quality of cancer care, including care received from the health care team, from the caregiver themselves, and in relation to patients' own self-management.

IMPLICATIONS FOR NURSING PRACTICE

Supporting caregivers has tangible consequences with regard to the quality of cancer care on multiple levels, with direct implications for patient outcomes. Nurses have a key role in providing psychosocial care to patients and their caregivers, and in supporting system-level change.

Difficulties in emotion regulation and chronic pain-related disability and opioid misuse

Risk for opioid misuse is a crucial consideration for patients with chronic pain, given the recent high rates of opioid-related deaths in the U.S. Emotion regulation difficulties may be associated with chronic pain outcomes such as opioid misuse, but may also be amenable to intervention. The aim of this study was to examine associations between difficulties with emotion regulation and disability and risk for opioid misuse among Appalachian chronic pain patients. The Difficulties in Emotion Regulation scale (DERS-18), Pain Disability Index (PDI), Screener and Opioid Assessment for Patients with Pain - Revised (SOAPP-R), and Current Opioid Misuse Measure (COMM) were collected from 149 patients (age 25-80, 59% female) presenting to a behavioral medicine department for evaluation. The extent to which DERS-18 scores predict risk for opioid misuse and disability was examined via hierarchical regression, logistic regression, and receiver operating characteristic (ROC) curve analyses. DERS-18 scores account for 45% of variance in SOAPP-R, 36% in COMM scores, and 11% in PDI scores. A one-point increase in DERS-18 score is associated with 19% greater odds of being at risk for misuse as measured by the SOAPP-R, and 16% greater odds on the COMM. In ROC analyses, the DERS-18 is a good predictor of risk on the SOAPP-R (AUC = .85) and COMM (.83), with cut-off scores in the mid-30s exhibiting good sensitivity and specificity. Difficulties in emotion regulation are associated with poorer functioning and with greater risk of opioid misuse in this population, but may be amenable to intervention.

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.

Enhancement of pain inhibition by working memory with anodal transcranial direct current stimulation of the left dorsolateral prefrontal cortex

The aim of this study was to examine whether transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (DLPFC) enhances pain inhibition by improving working memory (WM). Forty healthy volunteers participated in two tDCS sessions. Pain was evoked by electrical stimulation at the ankle. Participants performed an n-back task (0-back and 2-back). The experimental protocol comprised five counterbalanced conditions (0-back, 2-back, pain, 0-back with pain and 2-back with pain) that were performed twice (pre-tDCS baseline and during tDCS). Compared with the pre-tDCS baseline values, anodal tDCS decreased response times for the 2-back condition (p < 0.01) but not for the 0-back condition (p > 0.5). Anodal tDCS also decreased pain ratings marginally in the 2-back with pain condition, but not the 0-back with pain condition (p = 0.052 and p > 0.2, respectively). No effect was produced by sham tDCS for any condition (p > 0.2). These results indicate that tDCS of the left DLPFC may enhance pain inhibition by improving WM.