Elevated pain sensitivity is associated with reduced REM sleep in females with comorbid temporomandibular disorder and insomnia.

OBJECTIVE: Patients with chronic pain disorders, including Temporomandibular Disorders (TMDs) endorse high levels of sleep disturbances, frequently reporting reduced sleep quality. Despite this, little is known about the effect that daytime pain has on the microstructure and macro-architecture of sleep. Therefore, we aimed to examine the extent to which daytime pain sensitivity, measured using quantitative sensory testing (QST), is associated with objective sleep parameters the following night, including sleep architecture and power spectral density, in women with TMD. METHODS: : 144 females with myalgia and arthralgia by examination using the Diagnostic criteria for TMD completed a comprehensive QST battery consisting of General Pain Sensitivity, Central Sensitization Index, and Masseter Pressure Pain Threshold assessments. Polysomnography (PSG) was collected the same night to measure sleep architecture and calculate relative power in delta, theta, alpha, sigma, and beta power bands. RESULTS: Central Sensitization (B= -3.069, P = 0.009), General Pain Sensitivity Indices (B= -3.069, P = 0.007), and Masseter Pain Pressure Threshold (B = 0.030, P = 0.008) were significantly associated with lower REM% both before and after controlling for covariates. Pain sensitivity measures were not significantly associated with relative power in any of the spectral bands, nor with any other sleep architectural stages. CONCLUSIONS: Our findings demonstrate that higher generalized pain sensitivity, masseter pain pressure threshold, as well as central sensitization were associated with a lower percentage of REM in participants with myofascial pain and arthralgia of the masticatory system. These findings provide an important step toward understanding the mechanistic underpinnings of how chronic pain interacts with sleep physiology.

Sleep Disruption Moderates the Daily Dynamics of Affect and Pain in Sickle Cell Disease.

Persons with sickle cell disease (SCD) often experience pain that can interfere with quality of life and daily activities. Pain can modulated by affect and sleep continuity; however, few studies have explored how these factors complementarily influence pain in adults with SCD. The study aims were to investigate 1) whether pain levels were heightened on days characterized by low positive affect and high negative affect, and 2) whether the relationship between affect and pain was intensified following nights of disrupted sleep. Adults with SCD (N = 25) completed ecological momentary assessments and daily sleep diaries. Mixed models were used to analyze the main and interactive effects of daily affect (positive affect and negative affect) and sleep disruption (wake after sleep onset and frequency of awakenings) on both daily average pain and daily maximum pain. Results suggested that daily average pain and maximum pain tended to be higher on days of low positive affect and high negative affect. Furthermore, the frequency of nocturnal awakenings moderated the relationship between positive affect and pain. On days where there were higher frequencies of nocturnal awakenings, low positive affect was associated with both average and maximum pain; however, this association was not observed with lower frequencies of nocturnal awakenings. The association between negative affect and maximum pain was also stronger at higher levels of awakenings. Results highlight the relevance of adjunctive interventions that target affect among populations with SCD and further suggest that sleep continuity may further facilitate these interventions, highlighting the importance of multimodal treatments. PERSPECTIVE: This study examined the effects of affect and sleep on pain among adults with sickle cell disease (SCD). Higher pain occurred on days of low positive affect and high negative affect, particularly following nights of more frequent awakenings. These findings emphasize the importance of addressing affect and sleep in SCD treatment.

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.

Predictors of participation in online self-management programs: A longitudinal observational study.

PURPOSE/OBJECTIVE: Lack of patient participation and engagement remains a barrier to implementing effective online self-management and behavioral health interventions. Identifying patient characteristics associated with engagement rates may lead to interventions that improve engagement in traditional and online self-management programs. In this study, two online self-management and recovery programs were evaluated to identify factors that predict patient engagement. RESEARCH METHOD/DESIGN: Predictors were collected in a questionnaire at baseline before 435 participants started either of the two interventions. One or two online lessons were completed per week with seven or eight total lessons to complete in each program, and each lesson took about 20-30 min to finish. Full patient engagement was defined as completing all lessons and assessments in the program and partial engagement as attempting at least one lesson or assessment. RESULTS: Predictors of full patient engagement were self-rated confidence in completing the program or being over 60 years of age. Predictors of at least partial patient engagement were experienced ordering online or being over 50 years of age. CONCLUSIONS/IMPLICATIONS: Identifying profiles of individuals who predict poor engagement may improve implementation and the health outcomes of intervention programs. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Within subject, double blind, examination of opioid sensitivity in participant-reported, observed, physiologic, and analgesic outcomes.

Background: Inter-individual differences in opioid sensitivity may underlie different opioid risk profiles but have often been researched in persons who have current or past opioid use disorder or physical dependence. This study examined how opioid sensitivity manifests across various assessments of opioid effects in a primarily opioid-naïve population. Procedures: Data were harmonized from two within-subject, double-blind trials wherein healthy participants (N = 123) received placebo and 4 mg oral hydromorphone. Demographics, self-report ratings, observer ratings, physiological, and cold pressor measures were collected. Participants were categorized as being responsive or nonresponsive to the opioid dose tested and compared using mixed-models, Pearson product correlations, and paired t-tests. Findings: Participants were 49.6% female, mean 33.0 (SD=9.3) years old, and 44.7% Black/African American and 41.5% White, with 89.4% reporting no prior exposure to opioids. Within-subject sensitivity to opioids varied depending on the measure. One in five participants did not respond subjectively to the 4 mg hydromorphone dose based on their "Drug Effects" rating. Persons who were responsive showed more evidence of drug-dependent effects than did persons who were not responsive on ratings of Bad Effects (p= .03), feeling High (p= .01), Nausea (p= .03), pupil diameter (p< 0.01), and on the circular lights task (p< 0.001). Conclusions: This study provides initial evidence that the experience of opioids may be domain specific. Data suggest potentially clinically meaningful differences exist regarding opioid response patterns, evident following one dose among opioid inexperienced individuals.

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 (ß = 2.828), 3 (ß = 2.140), 6 (ß = 2.962), and 12 months (ß = 1.835) and pain at 6 weeks (ß = 6.722), 3 (ß = 5.536), and 6 months (ß = 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.

Medium- and Long-Term Effects of Insomnia Severity and Circadian Preference on Pain and Emotional Distress Among Individuals With Chronic Pain.

Studies have identified insomnia as having significant influence on chronic pain. A rising body of research has also underscored the association between eveningness and chronic pain. However, co-assessment of insomnia and eveningness in the context of chronic pain adjustment has been limited. The present study sought to investigate the effects of insomnia and eveningness on pain severity, pain interference, and emotional distress (ie, depressive and anxiety symptoms) over nearly 2 years among adults with chronic pain in the U.S. Adults with chronic pain (N = 884) were surveyed 3 times via Amazon's MTurk online crowdsourcing platform: baseline, 9-month follow-up, and 21-month follow-up. Path analysis was conducted to examine the effects of baseline insomnia severity (Insomnia Severity Index) and eveningness (Morningness and Eveningness Questionnaire), as well as their moderating effects on outcomes. Controlling for select sociodemographic variables and baseline outcome levels, greater insomnia severity at baseline was associated with worsening of all of the pain-related outcomes at 9-month follow-up, and pain interreference and emotional distress at 21-month follow-up. We did not find evidence that evening types are at a higher risk of experiencing worsening pain-related outcomes over time compared to morning and intermediate types. There were also no significant insomnia severity and eveningness moderation effects on any outcome. Our findings suggest that insomnia is a more robust predictor of changes in pain-related outcomes as compared to eveningness. Treatment of insomnia can be important in chronic pain management. Future studies should evaluate the role of circadian misalignment on pain using more accurate biobehavioral makers. PERSPECTIVE: This study examined the effects of insomnia and eveningness on pain and emotional distress in a large sample of individuals with chronic pain. Insomnia severity is a stronger predictor of changes in pain and emotional distress than eveningness, highlighting insomnia as an important clinical target for chronic pain management.

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.

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.

A randomized, placebo-controlled, double-blinded mechanistic clinical trial using endotoxin to evaluate the relationship between insomnia, inflammation, and affective disturbance on pain in older adults: A protocol for the sleep and Healthy Aging Research for pain (SHARE-P) study.

Chronic pain is prevalent in older adults. Treatment, especially with opioids, is often ineffective and poses considerable negative consequences in this population. To improve treatment, it is important to understand why older adults are at a heightened risk for developing chronic pain. Insomnia is a major modifiable risk factor for chronic pain that is ubiquitous among older adults. Insomnia can also lead to heightened systemic inflammation and affective disturbance, both of which may further exacerbate pain conditions in older adults. Endotoxin exposure can be used as an experimental model of systemic inflammation and affective disturbance. The current study aims to understand how insomnia status and endotoxin-induced changes in inflammation and affect (increased negative affect and decreased positive affect) may interact to impact pain facilitatory and inhibitory processes in older adults. Longitudinal data will also assess how pain processing, affective, and inflammatory responses to endotoxin may predict the development of pain and/or depressive symptoms. The current study is a randomized, double-blinded, placebo-controlled, mechanistic clinical trial in men and women, with and without insomnia, aged 50 years and older. Participants were randomized to either 0.8ng/kg endotoxin injection or saline placebo injection. Daily diaries were used to collect variables related to sleep, mood, and pain at two-week intervals during baseline and 3-, 6-, 9-, and 12-months post-injection. Primary outcomes during the experimental phase include conditioned pain modulation, temporal summation, and affective pain modulation ∼5.5 hours after injection. Primary outcomes for longitudinal assessments are self-reported pain intensity and depressive symptoms. The current study uses endotoxin as an experimental model for pain. In doing so, it aims to extend the current literature by: (1) including older adults, (2) investigating insomnia as a potential risk factor for chronic pain, (3) evaluating the role of endotoxin-induced affective disturbances on pain sensitivity, and (4) assessing sex differences in endotoxin-induced hyperalgesia. Clinicaltrialsgov: NCT03256760. Trial sponsor: NIH R01AG057750-01.

Within-subject, double-blind, randomized, placebo-controlled evaluation of combining the cannabinoid dronabinol and the opioid hydromorphone in adults with chronic pain.

The potential synergistic effects of combining cannabinoids and opioids for analgesia has received considerable attention. No studies to date have evaluated this combination in patients with chronic pain. The present study aimed to evaluate the combined analgesic and drug effects of oral opioid (hydromorphone) and delta-9-tetrahydrocannabinol (dronabinol), as well as their effects on physical and cognitive functioning, and human abuse potential (HAP) outcomes among individuals with knee osteoarthritis (KOA). This was a within-subject, double-blind, randomized, placebo-controlled study. Participants (N = 37; 65% women; mean age = 62) diagnosed with knee osteoarthritis of ≥3/10 average pain intensity were included. Participants received (1) placebo-placebo, (2) hydromorphone (4 mg)-placebo; (3) dronabinol (10 mg)-placebo, and (4) hydromorphone (4 mg)-dronabinol (10 mg). Clinical and experimentally-induced pain, physical and cognitive function, subjective drug effects, HAP, adverse events, and pharmacokinetics were evaluated. No significant analgesic effects were observed for clinical pain severity or physical functioning across all drug conditions. Little enhancement of hydromorphone analgesia by dronabinol was observed on evoked pain indices. While subjective drug effects and some HAP ratings were increased in the combined drug condition, these were not significantly increased over the dronabinol alone condition. No serious adverse events were reported; hydromorphone produced more mild adverse events than placebo, but hydromorphone + dronabinol produced more moderate adverse events than both placebo and hydromorphone alone. Only hydromorphone impaired cognitive performance. Consistent with laboratory studies on healthy adults, the present study shows minimal benefit of combining dronabinol (10 mg) and hydromorphone (4 mg) for analgesia and improving physical functioning in adults with KOA.

Individual Dimensions of Pain Catastrophizing Do Not Mediate the Effect of Sociodemographic and Psychological Factors on Chronic Orofacial Pain Severity, Interference, and Jaw Limitation: A Structural Equation Modeling Approach.

Pain catastrophization (PC), involving rumination, magnification, and helplessness, can be viewed as a coping strategy associated with chronic pain. PC is considered a driving force in mediating pain-related outcomes, but it is still unclear whether PC mediates the relationship between psychological and sociodemographic factors with chronic pain when considered in a single model. Using baseline data from a parent study, this study examined the effect of positive and negative psychological and sociodemographic factors on pain severity, interference, and jaw limitation mediated by the PC dimensions in a sample of 397 temporomandibular disorder (TMD) participants using structural equation modeling (SEM). SEM revealed that pain severity regressed on age, sex, education, and income; interference regressed on positive and negative psychological factors, education, and income; and jaw limitation regressed on age. The PC dimensions did not individually mediate these relationships. Although they jointly mediated the relationships between negative psychological factors and pain severity and between age and pain interference, the effect size was small, suggesting that PC is not a critical factor in mediating TMD pain outcomes. Reducing negative cognitions, not just PC, may be of greatest benefit to the most vulnerable TMD populations. PERSPECTIVE: This study examines sociodemographic and psychological factors that affect orofacial pain, finding that the pain catastrophizing dimensions do not mediate these relationships. Understanding which factors most strongly affect pain outcomes will help identify targets for intervention to produce the greatest benefit for the most vulnerable persons suffering from pain.

Determining Profiles of Pain-Specific and General Emotion Regulation Skills and Their Relation to 12-Month Outcomes Among People With Chronic Pain.

Difficulties with pain-specific emotion regulation (ER; eg, pain catastrophizing, pain acceptance) are associated with poor pain outcomes. Less is known about how general ER relates to pain outcomes, or the extent to which pain-specific and general ER interact. In a sample (N = 1,453) of adults with chronic pain, the current study used latent profile analysis to identify subgroups of people with distinct pain-specific and general ER profiles, and determined how subgroup membership at baseline related to pain severity, pain interference, depression and anxiety symptoms at 12-month follow-up. Four groups were identified: 1) general ER difficulties only (29.6%); 2) pain-specific and general ER difficulties (26.3%); 3) skillful pain-specific and general ER (24.6%); 4) pain-specific ER difficulties only (19.4%). Controlling for auto-correlation and demographic covariates, those with pain-specific and general ER difficulties had the worst outcomes in all domains. Membership to other groups did not differentiate between pain severity or interference outcomes; those skillful in pain-specific and general ER had the lowest depression and anxiety symptoms at 12 months. General ER difficulties are common among adults with chronic pain and raise relative risk when paired with pain-specific ER difficulties. Findings offer potential directions for individualizing pain psychology treatment. PERSPECTIVE: This article shows that people with chronic pain have different sets of strengths and difficulties when it comes to regulating emotions related and/or unrelated to the experience of pain itself. Understanding an individual's unique constellation of emotion regulation skills and difficulties might help personalize the psychological treatment of pain.

Depressive and Insomnia Symptoms Sequentially Mediate the Association Between Racism-Based Discrimination in Healthcare Settings and Clinical Pain Among Adults With Sickle Cell Disease.

Racism-based discrimination in healthcare settings has been associated with clinical pain in adults living with sickle cell disease; however, no studies have examined depressive and insomnia symptoms as mechanisms that may drive this relationship. This secondary data analysis examined associations between depressive and insomnia symptoms, racism-based discrimination, and clinical pain. Seventy-one adults with sickle cell disease (70% female, Mage = 38.79) provided baseline reports of racism-based discrimination, depressive symptoms, insomnia symptoms, and pain (severity, interference, catastrophizing), and they completed daily diaries of pain severity and interference over 3 months. In a sequential mediation model, baseline depressive (1st) and insomnia symptoms (2nd) significantly mediated the association between racism-based discrimination and baseline pain interference, average daily diary pain severity, and average daily diary pain interference. Although the mediation model with baseline pain severity as the outcome was significant, the total and direct effects were not. Results indicate that discrimination in healthcare settings contributes to depression, which may act on pain through sleep disturbance. Findings support the need for systemic and structural changes to eliminate discrimination in healthcare settings and behavioral mood and sleep interventions to reduce the impact of discrimination on clinical pain. PERSPECTIVE: The relationship between discrimination in healthcare settings and pain in adults with sickle cell disease may be driven by depression and sleep disturbance, modifiable risk factors and potential treatment targets. Results suggest that systemic, structural, and institutional changes must be implemented to promote better patient care and health outcomes.

Nocturnal Delta Power is Associated With Lower Next-Day Pain But Not Pain Catastrophizing: Results From a Cohort of Female Participants With Temporomandibular Joint Pain.

Existing data demonstrate reduced delta power during sleep in patients with depression and chronic pain. However, there has been little examination of the relationship between delta power and pain-reports, or pain-catastrophizing. We recruited female participants (n = 111) with insomnia and temporomandibular disorder, and measured nocturnal and daytime measures of pain and pain catastrophizing, and calculated relative nocturnal delta (0.5-4 Hz) power during sleep. We fit linear regression models, and further examined the moderating effect of depressive symptom severity. Lower relative delta power across the whole night was significantly associated with greater nocturnal pain (B = -20.276, P = .025, R2 = 0.214). Lower relative delta power during the first-third of the night, was associated with greater nocturnal pain (B = -17.807, p = 0.019, R2 = 0.217), next-day pain (B = 13.876, P = .039, R2 = 0.195), and next-morning pain (B = -15.751, P = .022, R2 = 0.198). Lower relative delta power during the final-third of the night was significantly associated with greater nocturnal (B = -17.602, P = .029, R2 = 0.207) and next-morning pain (3rd: B = -14.943, P = .042, R2 = 0.187). Depressive symptom severity did not moderate these relationships. Delta power was not significantly associated with nocturnal or daytime pain catastrophizing. These findings demonstrate that greater relative delta power during sleep is associated with lower nocturnal and next-day pain in patients with temporomandibular disorder. This data may guide the use of sleep interventions in clinical pain populations, with the aim of improving pain outcomes. PERSPECTIVE: This article presents data demonstrating an association between increased nocturnal delta power and reduced next-day pain. These findings may help promote interventions which aim to increase nocturnal delta power in clinical pain populations, with the goal of improving pain outcomes.

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.

Preliminary Evidence for the Sequentially Mediated Effect of Racism-Related Stress on Pain Sensitivity Through Sleep Disturbance and Corticolimbic Opioid Receptor Function.

Sleep disturbance predicts worse pain outcomes. Because sleep disturbance inequitably impacts Black adults - with racism as the upstream cause - understanding how racism-related stress impacts pain through sleep might help minimize racialized pain inequities. This preliminary study examined sequential mediation of the effect of racism-related stress on experimental pain through sleep disturbance and corticolimbic µOR function in pain-free non-Hispanic Black (NHB) and White (NHW) adults. Participants completed questionnaires, actigraphy, positron emission tomography, and sensory testing. We reproduced findings showing greater sleep disturbance and pain sensitivity among NHB participants; greater sleep disturbance (r = .35) and lower pain tolerance (r=-.37) were significantly associated with greater racism-related stress. In a sequential mediation model, the total effect of racism-related stress on pain tolerance (ß=-.38, P = .005) weakened after adding sleep disturbance and ventromedial prefrontal cortex (vmPFC) µOR binding potential (BPND) as mediators (ß = -.18, P = .16). The indirect effect was statistically significant [point estimate = -.003, (-.007, -.0003). Findings showed a potential sequentially mediated effect of racism-related stress on pain sensitivity through sleep disturbance and vmPFC µOR BPND. As policy efforts are enacted to eliminate the upstream cause of systemic racism, these results cautiously suggest that sleep interventions within racism-based trauma informed therapy might help prevent downstream effects on pain. PERSPECTIVE: This preliminary study identified the effect of racism-related stress on pain through sleep disturbance and mu-opioid receptor binding potential in the ventromedial prefrontal cortex. Findings cautiously support the application of sleep interventions within racism-based trauma-informed therapy to prevent pain inequities as policy changes function to eliminate all levels of racism.

A second dimension of somatosensory system injury? Thalamic volume loss and neuropathic pain in adults with cerebral palsy and periventricular white matter injury.

Objectives: Lemniscal (motor-related) and spinothalamic (neuropathic pain-related) somatosensory abnormalities affect different subsets of adults with cerebral palsy (CP). Lemniscal/motor abnormalities are associated with posterior thalamic radiation white matter disruption in individuals with CP and white matter injury. We tested the hypothesis that neuropathic pain symptoms in this population are rather associated with injury of the somatosensory (posterior group nuclei) thalamus. Methods: In this cross-sectional study, communicative adults with CP and bilateral white matter injury and neurotypical control participants volunteered to self-report pain symptoms and undergo research MRI. Posterior group thalamic nuclei volume was computed and correlated against neuropathic pain scores. Results: Participants with CP (n=6) had, on average, 24% smaller posterior group thalamic volumes (95% CI [10-39%]; corrected p=0.01) than control participants. More severe volume loss was correlated with more severe neuropathic pain scores (ρ=-0.87 [-0.99,-0.20]; p=0.02). Discussion: Association with thalamic volume loss suggests that neuropathic pain in adults with CP may frequently be central neuropathic pain. Complementing assessments of white matter microstructure, regional brain volumes hold promise as diagnostic biomarkers for central neuropathic pain in individuals with structural brain disorders.

The Influence of Expectancies on Pain and Function Over Time After Total Knee Arthroplasty.

OBJECTIVE: Expectancies have a well-documented influence on the experience of pain, responses to treatment, and postsurgical outcomes. In individuals with osteoarthritis, several studies have shown that expectations predict increased pain and disability after total knee replacement surgery. Despite the growing recognition of the importance of expectancies in clinical settings, few studies have examined the influence of expectancies throughout postsurgical recovery trajectories. The objective of the present study was to examine the role of presurgical expectancies on pain and function at 6-week, 6-month, and 1-year follow-ups after total knee arthroplasty. DESIGN AND PARTICIPANTS: Data were collected from patients scheduled for total knee arthroplasty 1 week before surgery and then at 6 weeks, 6 months, and 1 year after surgery. Correlational and multivariable regression analyses examined the influence of expectancies on patients' perceptions of pain reduction and functional improvement at each time point. Analyses controlled for age, sex, body mass index, presurgical pain intensity and function, pain catastrophizing, anxiety, and depression. RESULTS: Results revealed that expectancies significantly predicted pain reduction and functional improvement at 1-year follow-up. However, expectancies did not predict outcomes at the 6-week and 6-month follow-ups. Catastrophizing and depressive symptoms emerged as short-term predictors of postsurgical functional limitations at 6-week and 6-month follow-ups, respectively. CONCLUSIONS: The results suggest that targeting high levels of catastrophizing and depressive symptoms could optimize short-term recovery after total knee arthroplasty. However, the results demonstrate that targeting presurgical negative expectancies could prevent prolonged recovery trajectories, characterized by pain and loss of function up to 1 year after total knee arthroplasty.