[ 11 C]-PBR28 positron emission tomography signal as an imaging marker of joint inflammation in knee osteoarthritis

ABSTRACT

Although inflammation is known to play a role in knee osteoarthritis (KOA), inflammation-specific imaging is not routinely performed. In this article, we evaluate the role of joint inflammation, measured using [ 11 C]-PBR28, a radioligand for the inflammatory marker 18-kDa translocator protein (TSPO), in KOA. Twenty-one KOA patients and 11 healthy controls (HC) underwent positron emission tomography/magnetic resonance imaging (PET/MRI) knee imaging with the TSPO ligand [ 11 C]-PBR28. Standardized uptake values were extracted from regions-of-interest (ROIs) semiautomatically segmented from MRI data, and compared across groups (HC, KOA) and subgroups (unilateral/bilateral KOA symptoms), across knees (most vs least painful), and against clinical variables (eg, pain and Kellgren-Lawrence [KL] grades). Overall, KOA patients demonstrated elevated [ 11 C]-PBR28 binding across all knee ROIs, compared with HC (all P 's < 0.005). Specifically, PET signal was significantly elevated in both knees in patients with bilateral KOA symptoms (both P 's < 0.01), and in the symptomatic knee ( P < 0.05), but not the asymptomatic knee ( P = 0.95) of patients with unilateral KOA symptoms. Positron emission tomography signal was higher in the most vs least painful knee ( P < 0.001), and the difference in pain ratings across knees was proportional to the difference in PET signal ( r = 0.74, P < 0.001). Kellgren-Lawrence grades neither correlated with PET signal (left knee r = 0.32, P = 0.19; right knee r = 0.18, P = 0.45) nor pain ( r = 0.39, P = 0.07). The current results support further exploration of [ 11 C]-PBR28 PET signal as an imaging marker candidate for KOA and a link between joint inflammation and osteoarthritis-related pain severity.

Patient engagement in designing, conducting, and disseminating clinical pain research: IMMPACT recommended considerations

ABSTRACT

In the traditional clinical research model, patients are typically involved only as participants. However, there has been a shift in recent years highlighting the value and contributions that patients bring as members of the research team, across the clinical research lifecycle. It is becoming increasingly evident that to develop research that is both meaningful to people who have the targeted condition and is feasible, there are important benefits of involving patients in the planning, conduct, and dissemination of research from its earliest stages. In fact, research funders and regulatory agencies are now explicitly encouraging, and sometimes requiring, that patients are engaged as partners in research. Although this approach has become commonplace in some fields of clinical research, it remains the exception in clinical pain research. As such, the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials convened a meeting with patient partners and international representatives from academia, patient advocacy groups, government regulatory agencies, research funding organizations, academic journals, and the biopharmaceutical industry to develop consensus recommendations for advancing patient engagement in all stages of clinical pain research in an effective and purposeful manner. This article summarizes the results of this meeting and offers considerations for meaningful and authentic engagement of patient partners in clinical pain research, including recommendations for representation, timing, continuous engagement, measurement, reporting, and research dissemination.

Pain catastrophizing moderates the relationship between pain sensitivity and clinical pain in adolescents with functional abdominal pain

Pain catastrophizing has been linked to amplified pain sensitivity assessed using quantitative sensory testing (QST) in adults; pediatric data is limited, particularly in youth with functional abdominal pain (FAP). With increasing use of QST to evaluate somatosensory function and predict pain outcomes, we examined the associations between QST and clinical pain in adolescents with FAP and tested the moderating effects of pain catastrophizing. Seventy-seven adolescents (mean age 16.6 years, 85.7% female, 72.7% White, 90.8% non-Hispanic) who fulfilled diagnostic criteria for FAP completed QST assessment (pressure pain threshold and tolerance, heat pain threshold, conditioned pain modulation) and measures of abdominal pain intensity, pain interference and pain catastrophizing. Adjusting for age and sex, only higher heat pain threshold was associated with higher abdominal pain intensity (Beta per 1-SD = 0.54, P = 0.026). Contrary to hypothesis, for youth with higher pain catastrophizing, higher pressure pain tolerance was associated with greater abdominal pain intensity, but associations were not significant for youth with lower catastrophizing (P = 0.049). Similarly, for those with higher pain catastrophizing (in contrast to lower pain catastrophizing), higher pressure pain thresholds and tolerance were associated with higher pain interference (P = 0.039, 0.004, respectively). Results highlight the need to investigate the influence of pain catastrophizing on QST. PERSPECTIVE: This study demonstrated unexpected findings of pain catastrophizing moderating the relationships between pressure pain threshold and tolerance, and clinical pain in adolescents with FAP. This raised questions regarding our understanding of psychological contributions to QST findings in pediatric populations with chronic pain.

Brief Assessment of Patient Phenotype to Explain Variability in Postsurgical Pain and Opioid Consumption after Cesarean Delivery: Performance of a Novel Brief Questionnaire Compared to Long Questionnaires

BACKGROUND

Understanding factors that explain why some women experience greater postoperative pain and consume more opioids after cesarean delivery is crucial to building an evidence base for personalized prevention. Comprehensive psychosocial assessment with validated questionnaires in the preoperative period can be time-consuming. A three-item questionnaire has shown promise as a simpler tool to be integrated into clinical practice, but its brevity may limit the ability to explain heterogeneity in psychosocial pain modulators among individuals. This study compared the explanatory ability of three models: (1) the 3-item questionnaire, (2) a 58-item questionnaire (long) including validated questionnaires (e.g., Brief Pain Inventory, Patient Reported Outcome Measurement Information System [PROMIS]) plus the 3-item questionnaire, and (3) a novel 19-item questionnaire (brief) assessing several psychosocial factors plus the 3-item questionnaire. Additionally, this study explored the utility of adding a pragmatic quantitative sensory test to models.

METHODS

In this prospective, observational study, 545 women undergoing cesarean delivery completed questionnaires presurgery. Pain during local anesthetic skin wheal before spinal placement served as a pragmatic quantitative sensory test. Postoperatively, pain and opioid consumption were assessed. Linear regression analysis assessed model fit and the association of model items with pain and opioid consumption during the 48 h after surgery.

RESULTS

A modest amount of variability was explained by each of the three models for postoperative pain and opioid consumption. Both the brief and long questionnaire models performed better than the three-item questionnaire but were themselves statistically indistinguishable. Items that were independently associated with pain and opioid consumption included anticipated postsurgical pain medication requirement, surgical anxiety, poor sleep, pre-existing pain, and catastrophic thinking about pain. The quantitative sensory test was itself independently associated with pain across models but only modestly improved models for postoperative pain.

CONCLUSIONS

The brief questionnaire may be more clinically feasible than longer validated questionnaires, while still performing better and integrating a more comprehensive psychosocial assessment than the three-item questionnaire.

EDITOR’S PERSPECTIVE

Age, Race, Ethnicity, and Sex of Participants in Clinical Trials Focused on Chronic Pain

There is limited data on equitable inclusion in chronic pain trials. We aimed to 1) identify the frequency of reporting age, race, ethnicity, and sex in clinical trials targeting chronic pain, and 2) compare sociodemographic representation to the United States (US) population. We examined US-based intervention trials for chronic pain initiated between 2007 and 2021 and registered on ClinicalTrials.gov. We 1) assessed the frequency of reporting each demographic variable, 2) compared representation with US population estimates, and 3) explored change in reporting over time. Of 501 clinical trials, the frequency of reporting was as follows: 36.9% reported older adults, 54.3% reported race, 37.4% reported ethnicity, and 100% reported sex. Rates of race and ethnicity reporting increased, but older adult age reporting decreased over time (ps < .00001). Compared to 2020 US population estimates, there was an equitable representation of older adults, under-representation of individuals identifying as American Indian or Alaska Native (.8% vs .6%), Asian (5.6% vs 2.9%), Black or African American (12.6% vs 12.2%), with more than one race (2.9% vs 1.2%), and Hispanic/Latino (16.9% vs 14.1%). There was an over-representation of individuals identifying as Native Hawaiian or Pacific Islander (.2% vs .5%) or White (70.4% vs 72.9%), and of females (50.8% vs 68.4%). Some representation rates varied by chronic pain condition. Reporting of older adult age, race, and ethnicity was low in chronic pain trials in ClinicalTrials.gov, reinforcing the need for adhering to reporting guidelines. Representation varied across trials compared with US population data, particularly among those identifying as Hispanic/Latino and certain minority racial groups. PERSPECTIVE: Despite initiatives to increase the reporting of demographic information, doing so in clinical pain trials is far from ubiquitous. Moreover, efforts to improve diversity in these trials continue to be insufficient. Indeed, Black, Indigenous, and People of Color (BIPOC) remain under-represented in clinical pain trials.

Mindfulness-based Interventions for Chronic Low Back Pain: A Systematic Review and Meta-analysis

OBJECTIVE

This systematic review aimed to compile existing evidence examining the effects of mindfulness-based interventions (MBIs) for chronic low back pain (CLBP). CLBP leads to millions of disabled individuals in the United States each year. Current pharmacologic treatments are only modestly effective and may present long-term safety issues. MBIs, which have an excellent safety profile, have been shown in prior studies to be effective in treating CLBP yet remained underutilized.

DESIGN

Ovid/Medline, PubMed, Embase, and the Cochrane Library were searched for randomized controlled trials (RCTs), pilot RCTs, and single-arm studies that explored the effectiveness of MBIs in CLBP.

METHODS

Separate searches were conducted to identify trials that evaluated MBIs in reducing pain intensity in individuals with CLBP. A meta-analysis was then performed using R v3.2.2, Metafor package v 1.9-7.

RESULTS

Eighteen studies used validated patient-reported pain outcome measures and were therefore included in the meta-analysis. The MBIs included mindfulness meditation, mindfulness-based stress reduction, mindfulness-based cognitive therapy, mindfulness-oriented recovery enhancement, acceptance and commitment therapy, dialectical behavioral therapy, meditation-cognitive behavioral therapy, mindfulness-based care for chronic pain, self-compassion course, and loving-kindness course. Pain intensity scores were reported using a numerical rating scale (0 to 10) or an equivalent scale. The meta-analysis revealed that MBIs have a beneficial effect on pain intensity with a large-sized effect in adults with CLBP.

CONCLUSIONS

MBIs seem to be beneficial in reducing pain intensity. Although these results were informative, findings should be carefully interpreted due to the limited data the high variability in study methodologies, small sample sizes, inclusion of studies with high risk of bias, and reliance on pre-post treatment differences with no attention to maintenance of effects. More large-scale RCTs are needed to provide reliable effect size estimates for MBIs in persons with CLBP.

Pain coping, multidisciplinary care, and mHealth: Patients' views on managing advanced cancer pain

OBJECTIVE

Pain is common among people with advanced cancer. While opioids provide significant relief, incorporating psycho-behavioral treatments may improve pain outcomes. We examined patients' experiences with pain self-management and how their self-management of chronic, cancer-related pain may be complemented by behavioral mobile health (mHealth) interventions.

METHODS

We conducted semi-structured qualitative interviews with patients with advanced cancer and pain. Each participant reviewed content from our behavioral mHealth application for cancer pain management and early images of its interface. Participants reflected on their experiences self-managing cancer pain and on app content. Interviews were transcribed verbatim and analyzed using a combination of inductive and deductive thematic analysis.

RESULTS

Patients (n = 28; 54% female; mean age = 53) across two geographic regions reported using psychological strategies (e.g., reframing negative thoughts, distraction, pain acceptance, social support) to manage chronic cancer-related pain. Patients shared their perspectives on the integration of psycho-behavioral pain treatments into their existing medical care and their experiences with opioid hesitancy. Patient recommendations for how mHealth interventions could best support them coalesced around two topics: 1.) convenience in accessing integrated pharmacological and psycho-behavioral pain education and communication tools and 2.) relevance of the specific content to their clinical situation.

CONCLUSIONS

Integrated pharmacological and psycho-behavioral pain treatments were important to participants. This underscores a need to coordinate complimentary approaches when developing cancer pain management interventions. Participant feedback suggests that an mHealth intervention that integrates pain treatments may have the capacity to increase advanced cancer patients' access to destigmatizing, accessible care while improving pain self-management.

Individuals with fibromyalgia report greater pain sensitivity than healthy adults while listening to their favorite music: The contribution of negative affect

OBJECTIVE

We investigated the impact of favorite music on pain processing among individuals with fibromyalgia. We also examined differences in pain processing between individuals with fibromyalgia and healthy controls (HC) while listening to favorite music, and explored whether psychosocial factors contributed to these differences.

METHODS

Individuals with fibromyalgia and HC completed baseline psychosocial questionnaires and then underwent quantitative sensory testing (QST) during 3 randomized music conditions (meditative music, favorite music, white noise). Among individuals with fibromyalgia, Friedman tests were used to investigate differences in QST across conditions. Analyses of Covariance were used to examine group (HC vs. fibromyalgia) differences in QST during favorite music. Correlations were conducted to explore associations of baseline psychosocial factors with QST during favorite music. Mediation analyses were conducted to explore whether psychosocial factors contributed to greater pain sensitivity among individuals with fibromyalgia compared to HC during favorite music.

RESULTS

Individuals with fibromyalgia were less sensitive to pressure pain while listening to their favorite music compared to white noise. Compared to HC, individuals with fibromyalgia reported higher baseline negative affect and lower pain thresholds and tolerances during favorite music. Negative affect partially mediated the relationship between pain status (HC vs. fibromyalgia) and pain sensitivity during favorite music.

CONCLUSIONS

Individuals with fibromyalgia were less pain sensitive while listening to favorite music than white noise, although they were more sensitive than HC. Greater negative affect endorsed by individuals with fibromyalgia contributed to their greater pain sensitivity. Future studies should explore the impact of favorite music on clinical pain.

sEMG Biofeedback for Episodic Migraines: A Pilot Randomized Clinical Trial

The aim of this study was to assess the feasibility and potential effectiveness of a 6-week virtual sEMG biofeedback intervention for patients with episodic migraines. Patients with episodic migraines were randomized to treatment with a novel surface EMG (sEMG) at-home biofeedback device or a treatment as usual control group; they completed validated baseline and post-intervention assessments of migraine related disability (migraine-specific quality of life, anxiety and depression). Participants also underwent a series of Quantitative Sensory Testing (QST) procedures referring to several different tests that quantitatively assess responses to mechanical stimuli during two separate visits (baseline and post intervention). No adverse events were reported during the study. Compared to the treatment as usual comparison group, patients in the sEMG biofeedback group reported lower migraine disability (p < 0.05). Compared to baseline, participants in the sEMG biofeedback group demonstrated statistically significant reductions in anxiety (p < 0.01), and significant increases in quality of life (p < 0.001), and significant decreases in temporal summation (p < 0.05) assessed by QST. No significant changes were observed in any of the outcomes in the control comparison group (p > 0.05). No significant changes were observed in migraine frequency in either of the two groups (p > 0.05). In addition, mediation analyses revealed that changes in migraine related quality of life mediated group effects on changes in migraine disability. Virtual sEMG biofeedback shows promise as a potential therapy for reducing disability, anxiety and depression and improving quality of life in individuals with episodic migraines. These results demonstrate the feasibility of a digital intervention for migraines and set the basis for conducting a future, larger scale randomized controlled trial to confirm these preliminary findings.

A secondary analysis: the impact of pre-existing chronic pain among patients with cancer presenting to the emergency department with acute pain

PURPOSE

Patients with cancer may experience pain from cancer itself or its treatment. Additionally, chronic pain (CP) predating a patient's cancer diagnosis may make the etiology of pain less clear and the management of pain more complex. In this brief report, we investigated differences in biopsychosocial characteristics, pain severity, and opioid consumption, comparing groups of cancer patients with and without a history of CP who presented to the emergency department (ED) with a complaint of cancer-related pain.

METHODS

This secondary analysis of a prospective cohort study included patients with cancer who presented to the ED with a complaint of pain (≥ 4/10). Sociodemographic, clinical, psychological, and pain characteristics were assessed in the ED and subsequent hospitalization. Mann-Whitney U-, T-, and Chi-square tests were used to compare differences between patients with and without pre-existing CP before cancer.

RESULTS

Patients with pre-existing CP had lower income (p = 0.21) and less formal education (p = 0.25) and were more likely to have a diagnosis of depression or substance use disorder (p < 0.01). Patients with pre-existing CP reported significantly greater pain severity in the ED and during hospitalization compared to those without pre-existing CP (p < 0.05), despite receiving greater amounts of opioid analgesics (p = 0.036).

CONCLUSION

Identifying a history of pre-existing CP during intake may help identify patients with cancer with difficult to manage pain, who may particularly benefit from multimodal interventions and supportive care. In addition, referral of these patients for the management of co-occurring pain disorders may help decrease the usage of the ED for undertreated pain.

Development and pre-pilot testing of STAMP + CBT: an mHealth app combining pain cognitive behavioral therapy and opioid support for patients with advanced cancer and pain

PURPOSE

We developed and piloted a mobile health app to deliver cognitive behavioral therapy for pain (pain-CBT), remote symptom monitoring, and pharmacologic support for patients with pain from advanced cancer.

METHODS

Using an iterative process of patient review and feedback, we developed the STAMP + CBT app. The app delivers brief daily lessons from pain-CBT and pain psychoeducation, adapted for advanced cancer. Daily surveys assess physical symptoms, psychological symptoms, opioid utilization and relief. Just-in-time adaptive interventions generate tailored psychoeducation in response. We then conducted a single-arm pilot feasibility study at two cancer centers. Patients with advanced cancer and chronic pain used the app for 2 or 4 weeks, rated its acceptability and provided feedback in semi-structured interviews. Feasibility and acceptability were defined as ≥ 70% of participants completing ≥ 50% of daily surveys, and ≥ 80% of acceptability items rated ≥ 4/5.

RESULTS

Fifteen participants (female = 9; mean age = 50.3) tested the app. We exceeded our feasibility and accessibility benchmarks: 73% of patients completed ≥ 50% of daily surveys; 87% of acceptability items were rated ≥ 4/5. Participants valued the app's brevity, clarity, and salience, and found education on stress and pain to be most helpful. The app helped participants learn pain management strategies and decrease maladaptive thoughts. However, participants disliked the notification structure (single prompt with one snooze), which led to missed content.

CONCLUSION

The STAMP + CBT app was an acceptable and feasible method to deliver psychological/behavioral treatment with pharmacologic support for cancer pain. The app is being refined and will be tested in a larger randomized pilot study. TRN: NCT05403801 (05/06/2022).

Optimizing the use of ketamine to reduce chronic postsurgical pain in women undergoing mastectomy for oncologic indication: study protocol for the KALPAS multicenter randomized controlled trial

BACKGROUND

Mastectomies are commonly performed and strongly associated with chronic postsurgical pain (CPSP), more specifically termed postmastectomy pain syndrome (PMPS), with 25-60% of patients reporting pain 3 months after surgery. PMPS interferes with function, recovery, and compliance with adjuvant therapy. Importantly, it is associated with chronic opioid use, as a recent study showed that 1 in 10 patients continue to use opioids at least 3 months after curative surgery. The majority of PMPS patients are women, and, over the past 10 years, women have outpaced men in the rate of growth in opioid dependence. Standard perioperative multimodal analgesia is only modestly effective in prevention of CPSP. Thus, interventions to reduce CPSP and PMPS are urgently needed. Ketamine is well known to improve pain and reduce opioid use in the acute postoperative period. Additionally, ketamine has been shown to control mood in studies of anxiety and depression. By targeting acute pain and improving mood in the perioperative period, ketamine may be able to prevent the development of CPSP.

METHODS

Ketamine analgesia for long-lasting pain relief after surgery (KALPAS) is a phase 3, multicenter, randomized, placebo-controlled, double-blind trial to study the effectiveness of ketamine in reducing PMPS. The study compares continuous perioperative ketamine infusion vs single-dose ketamine in the postanesthesia care unit vs placebo for reducing PMPS. Participants are followed for 1 year after surgery. The primary outcome is pain at the surgical site at 3 months after the index surgery as assessed with the Brief Pain Inventory-short form pain severity subscale.

DISCUSSION

This project is part of the NIH Helping to End Addiction Long-term (HEAL) Initiative, a nationwide effort to address the opioid public health crisis. This study can substantially impact perioperative pain management and can contribute significantly to combatting the opioid epidemic.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05037123. Registered on September 8, 2021.

Thalamic neurometabolite alterations in chronic low back pain: a common phenomenon across musculoskeletal pain conditions?

ABSTRACT

Recently, we showed that patients with knee osteoarthritis (KOA) demonstrate alterations in the thalamic concentrations of several metabolites compared with healthy controls: higher myo-inositol (mIns), lower N-acetylaspartate (NAA), and lower choline (Cho). Here, we evaluated whether these metabolite alterations are specific to KOA or could also be observed in patients with a different musculoskeletal condition, such as chronic low back pain (cLBP). Thirty-six patients with cLBP and 20 healthy controls were scanned using 1 H-magnetic resonance spectroscopy (MRS) and a PRESS (Point RESolved Spectroscopy) sequence with voxel placement in the left thalamus. Compared with healthy controls, patients with cLBP demonstrated lower absolute concentrations of NAA ( P = 0.0005) and Cho ( P < 0.05) and higher absolute concentrations of mIns ( P = 0.01) when controlling for age, as predicted by our previous work in KOA. In contrast to our KOA study, mIns levels in this population did not significantly correlate with pain measures (eg, pain severity or duration). However, exploratory analyses revealed that NAA levels in patients were negatively correlated with the severity of sleep disturbance ( P < 0.01), which was higher in patients compared with healthy controls ( P < 0.001). Additionally, also in patients, both Cho and mIns levels were positively correlated with age ( P < 0.01 and P < 0.05, respectively). Altogether, these results suggest that thalamic metabolite changes may be common across etiologically different musculoskeletal chronic pain conditions, including cLBP and KOA, and may relate to symptoms often comorbid with chronic pain, such as sleep disturbance. The functional and clinical significance of these brain changes remains to be fully understood.

The role of sleep disturbance in reduced accuracy on a divided attention task among patients with fibromyalgia

Introduction

Patients with fibromyalgia show impaired cognitive performance compared with healthy, pain-free controls. Sleep disturbance, anxiety, and depression are highly prevalent among patients with fibromyalgia, and each is associated with impaired cognitive performance. Yet, limited work has explored whether psychosocial factors contribute to group differences in cognitive performance.

Objectives

This secondary data analysis investigated differences in cognitive performance between patients with fibromyalgia and healthy controls, and whether psychosocial factors accounted for these differences.

Methods

Adults with fibromyalgia (N = 24) and healthy, pain-free controls (N = 26) completed 2 cognitive tasks and the Patient-Reported Outcomes Measurement Information System sleep disturbance, anxiety, and depression short forms. Independent samples t tests were used to test for differences in cognitive performance between patients with fibromyalgia and healthy controls. Pearson correlations were conducted to examine associations between psychosocial factors and cognitive performance. Psychosocial factors significantly related to cognitive performance were explored as potential mediators of group differences in cognitive performance.

Results

Patients with fibromyalgia demonstrated poorer accuracy for divided attention compared with healthy controls, and sleep disturbance mediated this group difference. On the attentional switching task, healthy controls showed a greater switch-cost for accuracy compared with patients with fibromyalgia, but there was no group difference in reaction time. Anxiety and depression were not related to cognitive performance.

Conclusion

We found that patients with fibromyalgia reported greater sleep disturbance and, in turn, had poorer accuracy on the divided attention task. Sleep disturbance is modifiable with behavioral interventions, such as cognitive behavioral therapy, and may be a target for improving sleep quality and cognitive performance among patients with fibromyalgia.

A Randomized Controlled Neuroimaging Trial of Cognitive Behavioral Therapy for Fibromyalgia Pain

OBJECTIVE

Fibromyalgia (FM) is characterized by pervasive pain-related symptomatology and high levels of negative affect. Mind-body treatments such as cognitive behavioral therapy (CBT) appear to foster improvement in FM via reductions in pain-related catastrophizing, a set of negative, pain-amplifying cognitive and emotional processes. However, the neural underpinnings of CBT's catastrophizing-reducing effects remain uncertain. This randomized controlled mechanistic trial was designed to assess CBT's effects on pain catastrophizing and its underlying brain circuitry.

METHODS

Of 114 enrolled participants, 98 underwent a baseline neuroimaging assessment and were randomized to 8 weeks of individual CBT or a matched FM education control (EDU) condition.

RESULTS

Compared with EDU, CBT produced larger decreases in pain catastrophizing post treatment (P < 0.05) and larger reductions in pain interference and symptom impact. Decreases in pain catastrophizing played a significant role in mediating those functional improvements in the CBT group. At baseline, brain functional connectivity between the ventral posterior cingulate cortex (vPCC), a key node of the default mode network (DMN), and somatomotor and salience network regions was increased during catastrophizing thoughts. Following CBT, vPCC connectivity to somatomotor and salience network areas was reduced.

CONCLUSION

Our results suggest clinically important and CBT-specific associations between somatosensory/motor- and salience-processing brain regions and the DMN in chronic pain. These patterns of connectivity may contribute to individual differences (and treatment-related changes) in somatic self-awareness. CBT appears to provide clinical benefits at least partially by reducing pain-related catastrophizing and producing adaptive alterations in DMN functional connectivity.

Risk Factors for Self-Harm Ideation Among Persons Treated With Opioids for Chronic Low Back Pain

OBJECTIVES

Chronic pain is a significant health concern that adversely affects all aspects of life, including emotional well-being. Opioids are prescribed for the management of refractory, severe chronic pain, although they have been associated with adverse effects, including addiction and overdose. The aim of this study was to examine factors that predict thoughts of self-harm among adults with chronic pain who are prescribed opioids.

MATERIALS AND METHODS

Seven hundred sixty-five (N=765) persons with opioid-treated chronic lower back pain completed the Current Opioid Misuse Measure (COMM) and other validated questionnaires as part of a larger study. Response to 1 question from the COMM ("How often have you seriously thought about hurting yourself?") was used to assess suicide risk on a 5-point scale (0=never; 4=very often).

RESULTS

Participants were categorized into 3 groups according to their responses to the self-harm question: never (N=628; 82.1%), seldom or sometimes (N=74; 9.7%), and often or very often (N=63; 8.2%). Multivariate adjusted odds ratio (aOR) analyses indicated that reports of alcohol or drug overuse within the past month (aOR=1.41,[95% CI 1.11-1.78]), posttraumatic stress (PTSD; aOR=1.24,[1.07 to 1.44]), pain catastrophizing (aOR=1.03,[1.01 to 1.05]), not loving oneself (aOR=0.99,[.98-1.00]) and poor perceived mental health (aOR=0.94,[.92 to 97]) were most associated with thoughts of self-harm. Importantly, the ideation frequency of self-harm was highest among individuals treated with higher daily doses of opioids.

DISCUSSION

These results support the need for continued monitoring of adults treated with opioids for chronic pain, particularly among those on high-dose opioids who present with increased negative affect and concerns of substance misuse.

Perioperative insomnia trajectories and functional outcomes after total knee arthroplasty

ABSTRACT

Longitudinal total knee arthroplasty (TKA) studies indicate that a substantial percentage of patients continue to experience clinically significant pain and functional impairment after surgery. Insomnia has been associated with poorer surgical outcomes; however, previous work has largely focused on long-term postsurgical insomnia. This study builds on previous work by examining sleep and pain outcomes about perioperative insomnia trajectories. Insomnia symptoms (using the Insomnia Severity Index) during the acute perioperative period (2 weeks pre-TKA to 6 weeks post-TKA) were used to classify participants into perioperative insomnia trajectories: (1) No Insomnia (ISI < 8), (2) New Insomnia (baseline < 8; postoperative ≥ 8 or ≥6-point increase), (3) Improved Insomnia (baseline ≥ 8, postoperative < 8 or ≥6-point decrease), and (4) Persistent Insomnia (ISI ≥ 8). Insomnia, pain, and physical functioning were assessed in participants with knee osteoarthritis (n = 173; M age = 65 ± 8.3, 57.8% female) at 5 time points: 2 weeks pre-TKA, post-TKA: 6 weeks, 3 months, 6 months, and 12 months. Significant main effects were seen for insomnia trajectory and time, and trajectory-by-time interactions for postoperative insomnia, pain severity, and physical functioning ( P' s < 0.05). The Persistent Insomnia trajectory had the worst postoperative pain at all follow-ups and marked insomnia and physical functioning impairment post-TKA ( P' s < 0.05). The New Insomnia trajectory had notable long-term insomnia (6 weeks to 6 months) and acute (6 weeks) postoperative pain and physical functioning ( P' s < 0.05). Findings indicated a significant relationship between perioperative insomnia trajectory and postoperative outcomes. Results of this study suggest that targeting presurgical insomnia and preventing the development of acute postoperative insomnia may improve long-term postoperative outcomes, with an emphasis on persistent perioperative insomnia due to poorer associated outcomes.

Change in Pain-Related Anxiety Mediates the Effects of Psychophysiologic Symptom Relief Therapy (PSRT) on Pain Disability for Chronic Back Pain: Secondary Results from a Randomized Controlled Trial

Purpose

Widely used therapeutic approaches, such as cognitive-behavioral and mindfulness-based therapies, can improve pain and functioning in people with chronic back pain, but the magnitude and duration of their effects are limited. Our team developed a novel 12-week program, psychophysiologic symptom relief therapy (PSRT), to substantially reduce or eliminate pain and disability. This study examined whether PSRT helped more patients achieve large-magnitude (≥30%, ≥50%, ≥75%) reductions in back pain-related disability compared to mindfulness-based stress reduction (MBSR) and usual care (UC), and if the beneficial effects of PSRT were explained by reductions in pain-related anxiety following treatment.

Patients and Methods

Data from a three-armed randomized controlled trial were used (N=35 adults with chronic back pain). Change scores (baseline to 4-, 8-, 13-, and 26-weeks post-enrollment) were computed for back pain disability (RDQ) and pain-related anxiety (PASS-20). Fisher's exact tests and mediation analyses were conducted.

Results

Compared to MBSR and UC, PSRT helped significantly more patients achieve ≥75% reductions in back pain disability at all timepoints and in pain anxiety at all timepoints except 13-weeks. Change in pain anxiety significantly mediated the relationship between treatment group and change in back pain disability from baseline to 26-weeks.

Conclusion

PSRT helped more patients achieve substantial reductions in disability than an established treatment (MBSR) and usual care. Findings indicate reduced pain anxiety may be a mechanism by which PSRT confers long-term benefits on disability. Importantly, this work aims to move the field toward more precise and effective treatment for chronic back pain.

The mediating effect of social functioning on the relationship between catastrophizing and pain among patients with chronic low back pain

OBJECTIVE

Pain catastrophizing can be characterized as an interpersonal form of coping used to elicit support or empathy from others. Despite intentions of increasing support, catastrophizing can impair social functioning. While considerable work has addressed the relationship between catastrophizing and pain, limited empirical work has examined this relationship within a social context. First, we examined the role of catastrophizing as a potential contributor to group differences (chronic low back pain [cLBP] vs pain-free controls) in social functioning. Then we conducted a follow-up, exploratory analysis to examine the relationships between catastrophizing, social functioning, and pain within the subgroup of participants with cLBP.

METHODS

In this observational study, participants with cLBP (N = 62) and pain-free controls (N = 79) completed validated measures of pain, social functioning, and pain catastrophizing. A mediation analysis was conducted to examine whether catastrophizing mediated group differences (cLBP vs controls) in social functioning. A follow-up, exploratory mediation analysis then tested whether social functioning mediated the association between catastrophizing and pain within the subgroup of cLBP participants.

RESULTS

Participants with cLBP reported higher levels of pain, impaired social functioning, and higher catastrophizing compared to pain-free controls. Catastrophizing partially mediated the group difference in impaired social functioning. Additionally, social functioning mediated the association between higher catastrophizing and greater pain within the subgroup of cLBP participants.

CONCLUSIONS

We showed that impaired social functioning was driving the relationship between higher pain catastrophizing and worse pain among participants with cLBP. Interventions, such as cognitive behavioral therapy, should address catastrophizing in individuals with cLBP, while simultaneously improving social functioning.

Presurgical sleep and pain behaviors predict insomnia symptoms and pain after total knee arthroplasty: a 12-month longitudinal, observational study

OBJECTIVE

Up to 40% of individuals who undergo total knee arthroplasty (TKA) experience some degree of pain following surgery. Presurgical insomnia has been identified as a predictor of postsurgical pain; however, modifiable presurgical behaviors related to insomnia have received minimal attention. The objective of the present study was to develop a 2-item sleep and pain behavior scale (SP2) to investigate a maladaptive sleep and pain behavior and is a secondary analysis of a larger, parent study.

METHODS

Patients (N = 109) completed SP2 at baseline and 12 months and questionnaires assessing sleep and pain at baseline (pre-TKA), 6 weeks, 3, 6, and 12 months post-TKA. SP2 demonstrated adequate preliminary psychometric properties.

RESULTS

As hypothesized, even after controlling for baseline insomnia, pain, anxiety and other covariates, baseline SP2 predicted insomnia symptom severity at 6 weeks (β = 2.828), 3 (β = 2.140), 6 (β = 2.962), and 12 months (β = 1.835) and pain at 6 weeks (β = 6.722), 3 (β = 5.536), and 6 months (β = 7.677) post-TKA (P < .05). Insomnia symptoms at 6-weeks post-TKA mediated the effect of presurgical SP2 on pain at 3 (95% CI: 0.024-7.054), 6 (95%CI: 0.495-5.243), and 12 months (95% CI: 0.077-2.684).

CONCLUSIONS

This provides preliminary evidence that patients who cope with pain by retiring to their bed and bedroom have higher rates of post-surgical insomnia and pain and supports efforts to target this maladaptive sleep and pain behavior to reduce postsurgical pain.

Functional imaging studies of acute administration of classic psychedelics, ketamine, and MDMA: Methodological limitations and convergent results

Functional magnetic resonance imaging (fMRI) is increasingly used to non-invasively study the acute impact of psychedelics on the human brain. While fMRI is a promising tool for measuring brain function in response to psychedelics, it also has known methodological challenges. We conducted a systematic review of fMRI studies examining acute responses to experimentally administered psychedelics in order to identify convergent findings and characterize heterogeneity in the literature. We reviewed 91 full-text papers; these studies were notable for substantial heterogeneity in design, task, dosage, drug timing, and statistical approach. Data recycling was common, with 51 unique samples across 91 studies. Fifty-seven studies (54%) did not meet contemporary standards for Type I error correction or control of motion artifact. Psilocybin and LSD were consistently reported to moderate the connectivity architecture of the sensorimotor-association cortical axis. Studies also consistently reported that ketamine administration increased activation in the dorsomedial prefrontal cortex. Moving forward, use of best practices such as pre-registration, standardized image processing and statistical testing, and data sharing will be important in this rapidly developing field.

Does the Association Between Psychosocial Factors and Opioid Use After Elective Spine Surgery Differ by Sex in Older Adults?

Purpose

Psychosocial disorders have been linked to chronic postoperative opioid use and the development of postoperative pain. The potential interaction between sex and psychosocial factors with respect to opioid use after elective spine surgery in the elderly has not yet been evaluated. Our aim was to assess whether any observed association of anxiety or depression indicators with opioid consumption in the first 72 hours after elective spine surgery varies by sex in adults ≥65 years.

Patients and Methods

Secondary analysis of a retrospective cohort of 647 elective spine surgeries performed at Brigham and Women's Hospital, July 1, 2015-March 15, 2017, in patients ≥65. Linear mixed-effects models were used to test whether history of anxiety, anxiolytic use, history of depression, and antidepressant use were associated with opioid consumption 0-24, 24-48, and 48-72 post surgery, and whether these potential associations differed by sex.

Results

History of anxiety, anxiolytic use, history of depression, and antidepressant use were more common among women (51.3% of the sample). During the first 24 hours after surgery, men with a preoperative history of anxiety consumed an adjusted mean of 19.5 morphine milligram equivalents (MME) (99.6% CI: 8.1, 31.0) more than men without a history of anxiety; women with a history of anxiety only consumed an adjusted mean 2.9 MME (99.6% CI: -3.1, 8.9) more than women without a history of anxiety (P value for interaction between sex and history of anxiety <0.001). No other interactions were detected between sex and psychosocial factors with respect to opioid use after surgery.

Conclusion

Secondary analysis of this retrospective cohort study found minimal evidence that the association between psychosocial factors and opioid consumption after elective spine surgery differs by sex in adults ≥65.

Experiences of adults with opioid-treated chronic low back pain during the COVID-19 pandemic: A cross-sectional survey study

This study aimed to evaluate the impact of the COVID-19 pandemic on adults with opioid-treated chronic low back pain (CLBP), an understudied area. Participants in a "parent" clinical trial of non-pharmacologic treatments for CLBP were invited to complete a one-time survey on the perceived pandemic impact across several CLBP- and opioid therapy-related domains. Participant clinical and other characteristics were derived from the parent study's data. Descriptive statistics and latent class analysis analyzed quantitative data; qualitative thematic analysis was applied to qualitative data. The survey was completed by 480 respondents from June 2020 to August 2021. The majority reported a negative pandemic impact on their life (84.8%), with worsened enjoyment of life (74.6%), mental health (74.4%), pain (53.8%), pain-coping skills (49.7%), and finances (45.3%). One-fifth (19.4%) of respondents noted increased use of prescribed opioids; at the same time, decreased access to medication and overall healthcare was reported by 11.3% and 61.6% of respondents, respectively. Latent class analysis of the COVID-19 survey responses revealed 2 patterns of pandemic-related impact; those with worse pandemic-associated harms (n = 106) had an overall worse health profile compared to those with a lesser pandemic impact. The pandemic substantially affected all domains of relevant health-related outcomes as well as healthcare access, general wellbeing, and financial stability among adults with opioid-treated CLBP. A more nuanced evaluation revealed a heterogeneity of experiences, underscoring the need for both increased overall support for this population and for an individualized approach to mitigate harms induced by pandemic or similar crises.

Race differences in pain and pain-related risk factors among former professional American-style football players

ABSTRACT

The burden of pain is unequal across demographic groups, with broad and persisting race differences in pain-related outcomes in the United States. Members of racial and ethnic minorities frequently report more pervasive and severe pain compared with those in the majority, with at least some disparity attributable to differences in socioeconomic status. Whether race disparities in pain-related health outcomes exist among former professional football players is unknown. We examined the association of race with pain outcomes among 3995 former professional American-style football players who self-identified as either Black or White. Black players reported more intense pain and higher levels of pain interference relative to White players, even after controlling for age, football history, comorbidities, and psychosocial factors. Race moderated associations between several biopsychosocial factors and pain; higher body mass index was associated with more pain among White but not among Black players. Fatigue and psychosocial factors were more strongly related to pain among Black players relative to White players. Collectively, the substantial social and economic advantages of working as a professional athlete did not seem to erase race-related disparities in pain. We highlight an increased burden of pain among elite Black professional football players and identify race-specific patterns of association between pain and biopsychosocial pain risk factors. These findings illuminate potential future targets of interventions that may serve to reduce persistent disparities in the experience and impact of pain.

Pain catastrophizing is associated with reduced neural response to monetary reward

Introduction

Pain catastrophizing, a measure of an individual's negative emotional and cognitive appraisals of pain, has been included as a key treatment target in many psychological interventions for pain. However, the neural correlates of pain catastrophizing have been understudied. Prior neuroimaging evidence suggests that adults with pain show altered reward processing throughout the mesocorticolimbic reward circuitry.

Methods

In this study, we tested the association between Pain Catastrophizing Scale (PCS) scores and neural activation to the Monetary Incentive Delay (MID) reward neuroimaging task in 94 adults reporting a range of pain, insomnia, and mood symptoms.

Results

Results indicated that PCS score but not pain intensity was significantly associated with blunted activation in the caudate and putamen in response to feedback of successful vs. unsuccessful trials on the MID task. Mediation analyses indicated that PCS score fully mediated the relationship between depression symptoms and reward activation.

Discussion

These findings provide evidence that pain catastrophizing is independently associated with altered striatal function apart from depression symptoms and pain intensity. Thus, in individuals experiencing pain and/or co- morbid conditions, reward dysfunction is directly related to pain catastrophizing.

Back Pain Consortium (BACPAC): Protocol and Pilot Study Results for a Randomized Comparative-Effectiveness Trial of Antidepressants, Fear Avoidance Rehabilitation, or the Combination for Chronic Low Back Pain and Comorbid High Negative Affect

OBJECTIVE

Patients with chronic low back pain (CLBP) and comorbid depression or anxiety disorders are highly prevalent. Negative affect (NA) refers to a combination of negative thoughts, emotions, and behaviors. Patients with CLBP with high NA have greater pain, worse treatment outcomes, and greater prescription opioid misuse. We present the protocol for SYNNAPTIC (SYNergizing Negative Affect & Pain Treatment In Chronic pain).

DESIGN

A randomized comparative-effectiveness study of antidepressants, fear-avoidance rehabilitation, or their combination in 300 patients with CLBP with high NA. In the antidepressant- or rehabilitation-only arms, SYNNAPTIC includes an adaptive design of re-randomization after 4 months for nonresponders.

SETTING

A multisite trial conducted in routine pain clinical treatment settings: pain clinics and physical and occupational therapy treatment centers.

METHODS

Inclusion criteria include CLBP with elevated depression and anxiety symptoms. Antidepressant and rehabilitation treatments follow validated and effective protocols for musculoskeletal pain in patients with high NA. Power and sample size are based on superior outcomes of combination therapy with these same treatments in a 71-subject 4-arm pilot randomized controlled trial.

CONCLUSIONS

SYNNAPTIC addresses the lack of evidence-based protocols for the treatment of the vulnerable subgroup of patients with CLBP and high NA. We hypothesize that combination therapy of antidepressants plus fear-avoidance rehabilitation will be more effective than each treatment alone.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT04747314.

Change in Pain During Physical Activity Following Total Knee Arthroplasty: Associations With Improved Physical Function and Decreased Situational Pain Catastrophizing

Background and Objectives

Knee osteoarthritis is one of the primary causes of chronic pain among older adults and because of the aging population, the number of total knee arthroplasties (TKAs) performed is exponentially increasing. While pain reduction is a goal of TKA, movement-evoked pain is rarely assessed pre- and post-TKA. We characterized the distributions of change in pain, function, and situational catastrophizing in patients from presurgery to 3 months postsurgery and explored associations among these pre-post changes.

Research Design and Methods

This prospective study longitudinally assessed movement-evoked pain, function, and situational catastrophizing in patients with knee osteoarthritis (N = 92) using in-person performance-based tests (6-min walk test [6MWT], stair-climb test [SCT]) prior to and 3 months after TKA. Patients also completed the Western Ontario McMaster Universities Scales (WOMAC) pain and function subscales, and Pain Catastrophizing Scale, presurgery and 3- and 6-months postsurgery.

Results

Movement-evoked pain and function on performance tests significantly improved from pre- to post-TKA. Improved SCT function was associated with reduced SCT pain and catastrophizing. Similarly, reduced pain during the SCT was associated with reduced catastrophizing during the SCT. However, 6MWT function was not associated with 6MWT pain or catastrophizing; yet reduced pain during the 6MWT was associated with reduced catastrophizing during the 6MWT. Reduced movement-evoked pain during both performance tests was consistently associated with improved WOMAC function and pain, whereas improved function on performance tests was inconsistently associated with WOMAC function and pain. Notably, greater movement-evoked pain on both performance tests at 3-month post-TKA was associated with worse WOMAC function and pain at 6 months, whereas better function on performance tests at 3 months was associated with better WOMAC function, but not related to WOMAC pain at 6 months.

Discussion and Implications

Findings highlight the importance of situation-specific and in vivo assessments of pain and catastrophizing during physical activity.

Research objectives and general considerations for pragmatic clinical trials of pain treatments: IMMPACT statement

ABSTRACT

Many questions regarding the clinical management of people experiencing pain and related health policy decision-making may best be answered by pragmatic controlled trials. To generate clinically relevant and widely applicable findings, such trials aim to reproduce elements of routine clinical care or are embedded within clinical workflows. In contrast with traditional efficacy trials, pragmatic trials are intended to address a broader set of external validity questions critical for stakeholders (clinicians, healthcare leaders, policymakers, insurers, and patients) in considering the adoption and use of evidence-based treatments in daily clinical care. This article summarizes methodological considerations for pragmatic trials, mainly concerning methods of fundamental importance to the internal validity of trials. The relationship between these methods and common pragmatic trials methods and goals is considered, recognizing that the resulting trial designs are highly dependent on the specific research question under investigation. The basis of this statement was an Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) systematic review of methods and a consensus meeting. The meeting was organized by the Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership. The consensus process was informed by expert presentations, panel and consensus discussions, and a preparatory systematic review. In the context of pragmatic trials of pain treatments, we present fundamental considerations for the planning phase of pragmatic trials, including the specification of trial objectives, the selection of adequate designs, and methods to enhance internal validity while maintaining the ability to answer pragmatic research questions.

Feasibility and reliability of a quantitative sensory testing protocol in youth with acute musculoskeletal pain postsurgery or postinjury

ABSTRACT

Quantitative sensory testing (QST) is increasingly used in pediatric chronic pain; however, assessment in youth with acute musculoskeletal (MSK) pain is limited. This study evaluated the feasibility, reliability, and sources of variability of a brief QST protocol in 2 clinical samples of youth with acute MSK pain. Participants were 277 youth (M age = 14.5 years, SD = 2.0, range = 11-18 years, 59% female, 81% non-Hispanic) across 3 geographic study sites who completed a QST protocol assessing pressure and thermal pain sensitivity, temporal summation of pain, and conditioned pain modulation 8 weeks after MSK surgery (n = 100) or within 4 weeks after an acute MSK injury (n = 177). High feasibility was demonstrated by protocol completion rates ranging from 97.5% to 100% for each task, with 95.3% of youth completing all tasks. Reliability was high, with reliability coefficients of >0.97 for 7 out of 8 QST parameters and minimal influence of examiner or participating site effects. Younger youth had lower pressure and heat pain thresholds (11-12 vs 13-18 years, d = -0.80 to -0.56) and cold pain tolerance (d = -0.33). Hispanic youth had higher pressure and heat pain thresholds (d = 0.37-0.45) and pain ratings for cold pain tolerance (d = 0.54) compared with non-Hispanic youth. No significant differences were observed in QST values by sex or personal contextual factors at the time of assessment (momentary pain, menstrual period, use of pain medications). Overall findings demonstrate feasibility of a brief QST protocol with youth with diverse acute MSK pain and data provide initial support for the reliability of this QST protocol for multisite research studies.

Brain-to-brain mechanisms underlying pain empathy and social modulation of pain in the patient-clinician interaction

Social interactions such as the patient-clinician encounter can influence pain, but the underlying dynamic interbrain processes are unclear. Here, we investigated the dynamic brain processes supporting social modulation of pain by assessing simultaneous brain activity (fMRI hyperscanning) from chronic pain patients and clinicians during video-based live interaction. Patients received painful and nonpainful pressure stimuli either with a supportive clinician present (Dyadic) or in isolation (Solo). In half of the dyads, clinicians performed a clinical consultation and intake with the patient prior to hyperscanning (Clinical Interaction), which increased self-reported therapeutic alliance. For the other half, patient-clinician hyperscanning was completed without prior clinical interaction (No Interaction). Patients reported lower pain intensity in the Dyadic, relative to the Solo, condition. In Clinical Interaction dyads relative to No Interaction, patients evaluated their clinicians as better able to understand their pain, and clinicians were more accurate when estimating patients' pain levels. In Clinical Interaction dyads, compared to No Interaction, patients showed stronger activation of the dorsolateral and ventrolateral prefrontal cortex (dlPFC and vlPFC) and primary (S1) and secondary (S2) somatosensory areas (Dyadic-Solo contrast), and clinicians showed increased dynamic dlPFC concordance with patients' S2 activity during pain. Furthermore, the strength of S2-dlPFC concordance was positively correlated with self-reported therapeutic alliance. These findings support that empathy and supportive care can reduce pain intensity and shed light on the brain processes underpinning social modulation of pain in patient-clinician interactions. Our findings further suggest that clinicians' dlPFC concordance with patients' somatosensory processing during pain can be boosted by increasing therapeutic alliance.

Cannabinoid Therapy: Attitudes and Experiences of People With Chronic Pain

OBJECTIVE

Clinical trials of cannabinoids for chronic pain have mixed and often inconclusive results. In contrast, many prospective observational studies show the analgesic effects of cannabinoids. This survey study aimed to examine the experiences/attitudes of individuals with chronic pain who are currently taking, have previously taken, or never taken cannabinoids for chronic pain to inform future research.

METHODS

This study is based on a cross-sectional, web-based survey of individuals with self-reported chronic pain. Participants were invited to participate through an email that was distributed to the listservs of patient advocacy groups and foundations that engage individuals with chronic pain.

RESULTS

Of the 969 respondents, 444 (46%) respondents reported currently taking, 213 (22%) previously taken, and 312 (32%) never taken cannabinoids for pain. Participants reported using cannabinoids to treat a wide variety of chronic pain conditions. Those currently taking cannabinoids (vs previously) more frequently reported: (1) large improvements from cannabinoids in all pain types, including particularly difficult-to-treat chronic overlapping pain conditions (eg, pelvic pain), (2) improvements in comorbid symptoms (eg, sleep), and (3) lower interference from side effects. Those currently taking cannabinoids reported more frequent and satisfactory communication with clinicians regarding cannabinoid use. Those never taken cannabinoids reported a lack of suggestion/approval of a clinician (40%), illegality (25%), and lack of FDA regulation (19%) as reasons for never trying cannabinoids.

CONCLUSION

These findings underscore the importance of conducting high-quality clinical trials that include diverse pain populations and clinically relevant outcomes that if successful, could support FDA approval of cannabinoid products. Clinicians could then prescribe and monitor these treatments similarly to other chronic pain medications.

Brief Mindfulness-Based Cognitive Behavioral Therapy is Associated with Faster Recovery in Patients Undergoing Total Knee Arthroplasty: A Pilot Clinical Trial

OBJECTIVE

To assess whether brief mindfulness-based cognitive behavioral therapy (MBCBT) could enhance the benefits of total knee arthroplasty (TKA) in improving pain and pain-related disability. Specifically, to determine 1) whether patients who received MBCBT differed from matched controls who received treatment-as-usual with regard to postsurgical pain outcomes and 2) whether changes in pain catastrophizing, depression, or anxiety explained the potential effects of MBCBT on pain outcomes.

DESIGN

Pilot clinical trial.

SETTING

An academic teaching hospital serving a large urban and suburban catchment area surrounding the Boston, Massachusetts metropolitan region.

SUBJECTS

Sample of 44 patients undergoing TKA. Patients who completed a brief MBCBT intervention (n = 22) were compared with age-, race-, and sex-matched controls who received treatment-as-usual (n = 22).

METHODS

The MBCBT intervention included four 60-minute sessions delivered by a pain psychologist in person and via telephone during the perioperative period. Participants were assessed at baseline and at 6 weeks, 3 months, and 6 months after surgery.

RESULTS

Compared with matched controls, patients who received MBCBT had lower pain severity and pain interference at 6 weeks after surgery. Group differences in outcomes were mediated by changes in pain catastrophizing but not by changes in depression or anxiety. The MBCBT group had similar reductions in pain severity and interference as the control group did at 3 and 6 months after surgery.

CONCLUSIONS

This work offers evidence for a safe and flexibly delivered nonpharmacological treatment (MBCBT) to promote faster recovery from TKA and identifies change in pain catastrophizing as a mechanism by which this intervention could lead to enhanced pain-related outcomes.

To be aware, or to accept, that is the question: Differential roles of awareness of automaticity and pain acceptance in opioid misuse

BACKGROUND

Individuals with chronic low back pain (CLBP) are commonly prescribed long-term opioid therapy (LTOT) for analgesia, placing this population at increased risk for opioid misuse and opioid use disorder. Acceptance of aversive experiences (e.g., chronic pain) and awareness of automatic thoughts and behaviors (i.e., automaticity) are two facets of dispositional mindfulness that may serve as protective mechanisms against opioid misuse risk. Therefore, the aim of the current study was to examine the differential contributions of these constructs to opioid misuse risk among adults with CLBP receiving LTOT.

METHODS

Data were obtained from a sample of 770 adults with opioid-treated CLBP. Bivariate correlations and hierarchical linear regression analyses were used to determine whether chronic pain acceptance and awareness of automatic thoughts and behaviors explained a statistically significant portion of variance in opioid misuse risk after accounting for the effects of other relevant confounders.

RESULTS

Hierarchical regression results revealed that chronic pain acceptance and awareness of automatic thoughts and behaviors contributed a significant portion in the variance of opioid misuse risk. Awareness of automatic thoughts and behaviors was negatively associated with opioid misuse risk, such that individuals with lower levels of awareness of automaticity were at higher risk of opioid misuse. By contrast, pain acceptance was not associated with opioid misuse.

CONCLUSIONS

Findings suggest that awareness of automaticity may buffer against opioid misuse risk. Interventions designed to strengthen awareness of automaticity (e.g., mindfulness-based interventions) might be especially efficacious among this population.

Expectations for Improvement: A Neglected but Potentially Important Covariate or Moderator for Chronic Pain Clinical Trials

Variability in pain-related outcomes can hamper assay sensitivity of chronic pain clinical trials. Expectations of outcome in such trials may account for some of this variability, and thereby impede development of novel pain treatments. Measurement of participants' expectations prior to initiating study treatment (active or placebo) is infrequent, variable, and often unvalidated. Efforts to optimize and standardize measurement, analysis, and management of expectations are needed. In this Focus Article, we provide an overview of research findings on the relationship between baseline expectations and pain-related outcomes in clinical trials of pharmacological and nonpharmacological pain treatments. We highlight the potential benefit of adjusting for participants' expectations in clinical trial analyses and draw on findings from patient interviews to discuss critical issues related to measurement of expectations. We conclude with suggestions regarding future studies focused on better understanding the utility of incorporating these measures into clinical trial analyses. PERSPECTIVE: This focus article provides an overview of the relationship between participants' baseline expectations and pain-related outcomes in the setting of clinical trials of chronic pain treatments. Systematic research focused on the measurement of expectations and the impact of adjusting for expectations in clinical trial analyses may improve assay sensitivity.

Let’s Get Physical! A Comprehensive Review of Pre- and Post-Surgical Interventions Targeting Physical Activity to Improve Pain and Functional Outcomes in Spine Surgery Patients

The goal of this comprehensive review was to synthesize the recent literature on the efficacy of perioperative interventions targeting physical activity to improve pain and functional outcomes in spine surgery patients. Overall, research in this area does not yet permit definitive conclusions. Some evidence suggests that post-surgical interventions may yield more robust long-term outcomes than preoperative interventions, including large effect sizes for disability reduction, although there are no studies directly comparing these surgical approaches. Integrated treatment approaches that include psychosocial intervention components may supplement exercise programs by addressing fear avoidance behaviors that interfere with engagement in activity, thereby maximizing the short- and long-term benefits of exercise. Efforts should be made to test brief, efficient programs that maximize accessibility for surgical patients. Future work in this area should include both subjective and objective indices of physical activity as well as investigating both acute postoperative outcomes and long-term outcomes.

A Brief Overview: Sex Differences in Prevalent Chronic Musculoskeletal Conditions

Musculoskeletal (MSK) pain disorders are some of the most prevalent and disabling chronic pain conditions worldwide. These chronic conditions have a considerable impact on the quality of life of individuals, families, communities, and healthcare systems. Unfortunately, the burden of MSK pain disorders does not fall equally across the sexes. Females consistently demonstrate more prevalent and severe clinical presentations of MSK disorders, and this disparity increases in magnitude with age. The aim of the present article is to review recent studies that have examined sex differences between males and females in four of the most common MSK pain disorders: neck pain, low back pain, osteoarthritis, and rheumatoid arthritis.

Assessing the potential anti-neuroinflammatory effect of minocycline in chronic low back pain: Protocol for a randomized, double-blind, placebo-controlled trial

INTRODUCTION

Both preclinical studies, and more recent clinical imaging studies, suggest that glia-mediated neuroinflammation may be implicated in chronic pain, and therefore might be a potential treatment target. However, it is currently unknown whether modulating neuroinflammation effectively alleviates pain in humans. This trial tests the hypothesis that minocycline, an FDA-approved tetracycline antibiotic and effective glial cell inhibitor in animals, reduces neuroinflammation and may reduce pain symptoms in humans with chronic low back pain.

METHODS AND ANALYSIS

This study is a randomized, double-blind, placebo-controlled clinical trial. Subjects, aged 18-75, with a confirmed diagnosis of chronic (≥ six months) low back pain (cLBP) and a self-reported pain rating of at least four out of ten (for at least half of the days during an average week) are enrolled via written, informed consent. Eligible subjects are randomized to receive a 14-day course of either active drug (minocycline) or placebo. Before and after treatment, subjects are scanned with integrated Positron Emission Tomography/Magnetic Resonance Imaging (PET/MRI) using [¹¹C]PBR28, a second-generation radiotracer for the 18 kDa translocator protein (TSPO), which is highly expressed in glial cells and thus a putative marker of neuroinflammation. Pain levels are evaluated via daily surveys, collected seven days prior to the start of medication, and throughout the 14 days of treatment. General linear models will be used to assess pain levels and determine the treatment effect on brain (and spinal cord) TSPO signal.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT03106740).

Biofeedback EMG alternative therapy for chronic low back pain (the BEAT-pain study)

Objective

The aim of this study was to assess the feasibility and potential effectiveness of an 8-week virtual EMG biofeedback intervention for patients with CLBP.

Methods

Patients with CLBP completed validated baseline and post-intervention assessments of pain intensity and interference (Brief Pain Inventory), back pain-related disability (Oswestry Disability Index), anxiety and depression (Hospital Anxiety and Depression Scale). Participants underwent a series of Quantitative Sensory Testing (QST) procedures assessing responses to mechanical stimuli during two separate visits (baseline and post-intervention). In addition, we assessed, using surface EMG, the muscle tension in the trapezius, latissimus, and low back muscles at each session. Patients were randomized into the EMG biofeedback intervention or usual care group. Factorial analysis of variance including the interaction between treatment group and time was used to analyze the changes in pain intensity (primary outcome), pain interference, disability (secondary outcomes), anxiety, and depression (secondary outcomes).

Results

Compared to the treatment as usual comparison group, patients in the EMG biofeedback group reported lower pain intensity after completing the intervention (mean group difference 0.9, 95% CI -1.07, -0.32; p≤0.01). Compared to baseline, participants in the EMG biofeedback group demonstrated statistically significant reductions in pain interference (mean difference 1.3, 95% CI 0.42, 2.1; p≤0.01), disability (mean difference 4.32, 95% CI 1.2, 7.3; p≤0.01), and significant increases in low back pain thresholds (mean difference 0.5, 95% CI -0.87, -0.05; p≤0.01), assessed by QST. However, no significant group by time effects were observed for secondary outcomes: pain interference, disability, and low back pain thresholds. In addition, significant changes were observed in muscle tension for the trapezius, latissimus, and low back muscles in the EMG biofeedback group (p<0.001).

Conclusions

Virtual EMG biofeedback shows promise as a potential therapy for reducing pain and disability in individuals with chronic nonspecific low back pain.

Optimizing and Accelerating the Development of Precision Pain Treatments for Chronic Pain: IMMPACT Review and Recommendations

Large variability in the individual response to even the most-efficacious pain treatments is observed clinically, which has led to calls for a more personalized, tailored approach to treating patients with pain (ie, "precision pain medicine"). Precision pain medicine, currently an aspirational goal, would consist of empirically based algorithms that determine the optimal treatments, or treatment combinations, for specific patients (ie, targeting the right treatment, in the right dose, to the right patient, at the right time). Answering this question of "what works for whom" will certainly improve the clinical care of patients with pain. It may also support the success of novel drug development in pain, making it easier to identify novel treatments that work for certain patients and more accurately identify the magnitude of the treatment effect for those subgroups. Significant preliminary work has been done in this area, and analgesic trials are beginning to utilize precision pain medicine approaches such as stratified allocation on the basis of prespecified patient phenotypes using assessment methodologies such as quantitative sensory testing. Current major challenges within the field include: 1) identifying optimal measurement approaches to assessing patient characteristics that are most robustly and consistently predictive of inter-patient variation in specific analgesic treatment outcomes, 2) designing clinical trials that can identify treatment-by-phenotype interactions, and 3) selecting the most promising therapeutics to be tested in this way. This review surveys the current state of precision pain medicine, with a focus on drug treatments (which have been most-studied in a precision pain medicine context). It further presents a set of evidence-based recommendations for accelerating the application of precision pain methods in chronic pain research. PERSPECTIVE: Given the considerable variability in treatment outcomes for chronic pain, progress in precision pain treatment is critical for the field. An array of phenotypes and mechanisms contribute to chronic pain; this review summarizes current knowledge regarding which treatments are most effective for patients with specific biopsychosocial characteristics.

Does gabapentin provide benefit for patients with knee OA? A benefit-harm and cost-effectiveness analysis

OBJECTIVE

Gabapentin can treat neuropathic pain syndromes and has increasingly been prescribed to treat nociplastic pain. Some patients with knee osteoarthritis (OA) suffer from both nociceptive and nociplastic pain. We examined the cost-effectiveness of adding gabapentin to knee OA care.

METHOD

We used the Osteoarthritis Policy Model, a validated Monte Carlo simulation of knee OA, to examine the value of gabapentin in treating knee OA by comparing three strategies: 1) usual care, gabapentin sparing (UC-GS); 2) targeted gabapentin (TG), which provides gabapentin plus usual care for those who screen positive for nociplastic pain on the modified PainDETECT questionnaire (mPD-Q) and usual care only for those who screen negative; and 3) universal gabapentin plus usual care (UG). Outcomes included cumulative quality-adjusted life years (QALYs), lifetime direct medical costs, and incremental cost-effectiveness ratios (ICERs), discounted at 3% annually. We derived model inputs from published literature and national databases and varied key input parameters in sensitivity analyses.

RESULTS

UC-GS dominated both gabapentin-containing strategies, as it led to lower costs and more QALYs. TG resulted in a cost increase of $689 and a cumulative QALY reduction of 0.012 QALYs. UG resulted in a further $1,868 cost increase and 0.036 QALY decrease. The results were robust to plausible changes in input parameters. The lowest TG strategy ICER of $53,000/QALY was reported when mPD-Q specificity was increased to 100% and AE rate was reduced to 0%.

CONCLUSION

Incorporating gabapentin into care for patients with knee OA does not appear to offer good value.

Benzodiazepine Use and Dependence in Relation to Chronic Pain Intensity and Pain Catastrophizing

Benzodiazepines (BZDs), a class of sedative-hypnotic medications, generated concern as their popularity grew, with particular alarm regarding elevated rates of BZD use among chronic pain populations. Consistent with negative reinforcement/motivational models of substance use, desire for pain alleviation may motivate BZD use. Yet, little is known about relations between pain and addiction-relevant BZD use processes. This cross-sectional survey study aimed to: a) test associations between pain intensity and clinically relevant BZD use patterns, and b) examine the role of pain catastrophizing in hypothesized pain-BZD relations. Participants included 306 adults with chronic musculoskeletal pain and a current BZD prescription who completed an online survey study (Mage = 38.7, 38.9% female). Results indicated that pain intensity was positively associated with past-month BZD use frequency, BZD dependence severity, and likelihood of endorsing BZD misuse behaviors (ps < .05). Pain catastrophizing was positively associated with BZD dependence/likelihood of BZD misuse, covarying for pain intensity (P < .05). These findings build upon an emerging literature by highlighting positive covariation of pain intensity and pain catastrophizing with addiction-relevant BZD use behaviors. Results underscore the need to further investigate high-risk BZD use among individuals with chronic pain, with and without concurrent opioid use, to inform prevention/intervention efforts. PERSPECTIVE: This article presents findings on cross-sectional associations of pain intensity and pain catastrophizing with clinically relevant benzodiazepine (BZD) use outcomes, including dependence and misuse, among individuals with chronic pain. Findings help elucidate the higher burden of BZD misuse/dependence in chronic pain populations and suggest that pain relief may be a common, yet under recognized, self-reported motivation for taking BZDs.

Perioperative Sleep Disturbance Following Mastectomy: A Longitudinal Investigation of the Relationship to Pain, Opioid Use, Treatment, and Psychosocial Symptoms

OBJECTIVES

Sleep disturbance negatively impacts the quality of life and recovery. Our objective was to evaluate the relationship between the individual patient and surgical factors with greater sleep disturbance following breast surgery.

METHODS

In this prospective longitudinal study, patients completed validated measures regarding sleep disturbance, pain, opioid use, and psychological symptoms preoperatively and then 2 weeks, 6 and 12 months postoperatively. Univariable and multivariable generalized estimating equations evaluated demographic, surgical, pain, and psychological predictors of sleep disturbance during the first year after breast surgery.

RESULTS

Female patients (n=259) reported varying degrees of sleep disturbance, which were longitudinally associated with pain and psychosocial factors (eg, anxiety, depression, and affect). Independent preoperative predictors of worse sleep disturbance included younger age (B=-0.09, P =0.006), opioid use (B=3.09, P =0.02), and higher pain (B=0.19, P =<0.001) and anxiety (B=0.45, P =<0.001) at baseline. In addition, higher baseline positive affect (B=-0.14, P =<0.012) and the surgical category total mastectomy without reconstruction (B=-2.81, P =<0.006) were independently associated with lower sleep disturbance. Those with worse baseline sleep required more opioid analgesics during surgical recovery, and continued use of opioids at 2 weeks postsurgery was associated with disturbed sleep.

DISCUSSION

Certain patient characteristics, including younger age and baseline anxiety, positive affect, pain, and opioid use, were associated with greater sleep disturbance in the first year after breast surgery. Sleep disturbance was also associated with the greater perioperative and postoperative opioid requirements. Preoperative interventions (eg, anxiety management, cultivating positive affect, and multimodal pain management) in high-risk individuals may enhance sleep and recovery postoperatively, and allow more moderate and less prolonged opioid use.