The association between changes in clinical pain severity and IL-6 reactivity among patients undergoing total knee Arthroplasty: The moderating role of change in insomnia.

Knee osteoarthritis (KOA) is linked to an enhanced release of interleukin-6 (IL-6). Increased levels of IL-6 are associated with greater pain and insomnia. While total knee arthroplasty (TKA) typically results in the reduction of pain, for a subgroup of patients, pain does not improve. Understanding patients' propensity to upregulate IL-6 may provide insight into variation in the clinical success of TKA for improving pain, and insomnia may play an important modulatory role. We investigated the association between pre- and post-surgical changes in clinical pain and IL-6 reactivity, and whether change in insomnia moderated this association. Patients (n = 39) with KOA came in-person before and 3-months after TKA. At both visits, patients completed validated measures of clinical pain and insomnia, as well as underwent quantitative sensory testing (QST). Blood samples were collected to analyze IL-expression both before and after QST procedures to assess changes in IL-6 in response to QST (IL-6 reactivity). Patients were categorized into two groups based on change in clinical pain from pre- to post-surgery: 1) pain decreased > 2 points (pain improved) and 2) pain did not decrease > 2 points (pain did not improve). Based on this definition, 49 % of patients had improved pain at 3-months. Among patients with improved pain, IL-6 reactivity significantly decreased from pre- to post-surgery, whereas there was no significant change in IL-6 reactivity among those whose pain did not improve. There was also a significant interaction between pain status and change in insomnia, such that among patients whose insomnia decreased over time, improved pain was significantly associated with a reduction in IL-6 reactivity. However, among patients whose insomnia increased over time, pain status and change in IL-6 reactivity were not significantly associated. Our findings suggest that the resolution of clinical pain after TKA may be associated with discernible alterations in pro-inflammatory responses that can be measured under controlled laboratory conditions, and this association may be moderated by perioperative changes in insomnia. Randomized controlled trials which carefully characterize the phenotypic features of patients are needed to understand how and for whom behavioral interventions may be beneficial in modulating inflammation, pain, and insomnia.

Altered pain processing and sensitization in sickle cell disease: a scoping review of quantitative sensory testing findings.

OBJECTIVES: Over 50% of adults living with sickle cell disease (SCD) have chronic pain, but the underlying mechanisms of chronic pain in this population remain unclear. Quantitative sensory testing is an important measurement tool for understanding pain and sensory processing. This scoping review summarizes quantitative sensory testing methodologies used in sickle cell studies and the evidence for central sensitization in this population. METHODS: We conducted a systematic search of PubMed, Embase, and CINAHL to identify studies using quantitative sensory testing in individuals living with sickle cell disease. Search strategies were based on variations of the terms "sickle cell disease," and "quantitative sensory testing." Eligible studies were observational or experimental studies in human participants living with SCD that reported findings and detailed methodology for at least 1 quantitative sensory testing modality. RESULTS: Our search yielded a total of 274 records; 27 of which are included in this scoping review. Of the 27 studies, 17 were original studies (with combined total of 516 adult and 298 pediatric participants), and 10 were secondary or subgroup analyses of these prior studies. Significant variation existed in quantitative sensory testing methodologies across studies, including testing locations, type and intensity of stimuli, and interpretation of findings. Of the identified studies, 22% (2/9 studies) reported sensory abnormalities in mechanical sensitivity and thresholds, 22% (2/9 studies) reported abnormal pressure pain thresholds, 46% (6/13 studies) reported sensory abnormalities in thermal pain thresholds and tolerance (cold and warm), and 50% (2/4 studies) reported abnormalities in temporal summation. CONCLUSION: Future studies should use standardized quantitative sensory testing protocols with consistent and operationalized definitions of sensitization to provide clear insight about pain processing and central sensitization in sickle cell disease.

Elevated pain sensitivity is associated with reduced rapid eye movement (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 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 = .009), General Pain Sensitivity Indices (B = -3.069, P = .007), and Masseter Pain Pressure Threshold (B = 0.030, P = .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.

Children with sexual behavior problems: Ties to child maltreatment, family functioning, and help-seeking.

Although the literature on children's sexual behavior problems (SBPs) has indicated that maltreatment and family dysfunction are linked to SBPs, several facets of these factors have remained unexamined. Prior research has largely focused on SBPs more broadly, though interpersonal SBPs (ISBPs) are likely a distinct, more severe SBP subtype. The aim of the current study was to examine potentially relevant, unexplored factors, including the number of types of and total allegations of maltreatment as well as familial characteristics (i.e., parenting attitudes and behaviors, discipline methods, family functioning, and help-seeking) in relation to SBPs and ISBPs. The present study included 8-year-old children (N = 1,011, 51.1% female, 53.8% Black) and their caregivers from the Longitudinal Studies of Child Abuse and Neglect (LONGSCAN) study. In the model for SBPs, externalizing symptoms, the number of types of maltreatment allegations, maladaptive discipline methods, and help-seeking were associated with SBPs, whereas child's gender, race/ethnicity, internalizing symptoms, total maltreatment allegations, income, family functioning, and parenting attitudes were unrelated, r2 = .23. When ISBPs were examined, only child's gender and externalizing symptoms were tied to ISBPs, r2 = .09. However, child's race/ethnicity and internalizing symptoms, as well as maltreatment experiences, family factors, and help-seeking, were not associated with ISBPs. These findings highlight the importance of broader externalizing symptoms for both SBPs and ISBPs as well as the role of multiple types of maltreatment, parenting behavior, and help-seeking in the context of general SBPs.

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.

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.

Comparing Pain and Pain Coping Mechanisms in Patients Undergoing Total Joint Arthroplasty as Part of a Mission Trip to Those in the United States.

BACKGROUND: Access to total joint arthroplasty can be difficult in low-resource settings. Service trips are conducted to provide arthroplasty care to populations in need around the world. This study aimed to compare the pain, function, surgical expectations, and coping mechanisms of patients from one such service trip to the United States. METHODS: In 2019, the Operation Walk program conducted a service trip in Guyana during which 50 patients had hip or knee arthroplasties. Patient demographics, patient-reported outcome measures, questionnaires assessing pain attitudes and coping, and pain visual analog scales were collected preoperatively and at 3 months postoperatively. These outcomes were compared with a matched cohort of elective total joint arthroplasty at a US tertiary care medical center. There were 37 patients matched between the 2 cohorts. RESULTS: The mission cohort had significantly lower preoperative self-reported function scores than the US cohort (38.3 versus 47.5, P = .003), as well as a significantly larger improvement at 3 months (42.4 versus 26.4, P = .014). The mission cohort had significantly higher initial pain (8.0 versus 7.0, P = .015), but there were no differences with regard to pain at 3 months (P = .420) or change in pain (P = .175). The mission cohort had significantly greater preoperative scores in pain attitude and coping responses. CONCLUSION: Patients in low-resource settings were more likely to have preoperative functional limitations and pain, and they coped with pain through prayer. Understanding the key differences between these 2 types of populations and how they approach pain and functional limitations may help improve care for each group. LEVEL OF EVIDENCE: II, prospective study.

Sleep, Positive Affect, and Circulating Interleukin-6 in Women With Temporomandibular Joint Disorder.

OBJECTIVE: Systemic inflammation is commonly observed in idiopathic chronic pain conditions, including temporomandibular joint disorder (TMD). Trait positive affect (PA) is associated with lower inflammation in healthy controls, but those effects may be threatened by poor sleep. The associations between PA with proinflammatory cytokine activity and potential moderation by sleep in chronic pain are not known. We thus investigated the association between PA and circulating interleukin-6 (IL-6) and moderation of that association by sleep in a sample of women with TMD and sleep difficulties. METHODS: Participants (n = 110) completed the insomnia severity index and provided blood samples at five intervals throughout an evoked pain testing session. They then completed a 14-day diary assessing sleep and affect, along with wrist actigraphy. RESULTS: There was not a significant main effect of PA on resting or pain-evoked IL-6 (b = 0.04, p = .33). Diary total sleep time (b = -0.002, p = .008), sleep efficiency (b = -0.01, p = .005), sleep onset latency (b = 0.006, p = .010), and wake after sleep onset (b = 0.003, p = .033) interacted with PA to predict IL-6, such that PA inversely predicted IL-6 at higher levels of total sleep time and sleep efficiency and at lower levels of sleep onset latency and wake after sleep onset. Surprisingly, when sleep was poor, PA predicted greater IL-6. CONCLUSIONS: The potential salutary effects of PA on resting IL-6 erode when sleep is poor, underscoring the importance of considering sleep in conceptual and intervention models of TMD.

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.

Maternal support and caregiver-child symptom concordance among sexually abused children.

Caregivers and children often diverge in their reports of children's trauma-related symptoms, and this discordance has been linked with children's behavioral difficulties and poorer treatment outcomes. Knowledge regarding what factors may be related to discordance is limited, and maternal support in relation to trauma-related symptom agreement has yet to be investigated. The aim of the present study was to examine the associations between discordance and both maternal emotional support and blame/doubt in caregivers' and children's reports of trauma-related symptoms in sexually abused children. Participants were treatment-seeking, sexually abused children (N = 122) aged 8-12 years (M = 9.45 years, SD = 1.09; 70.5% female, 57.4% White) and their nonoffending caregivers. Low intraclass correlation coefficients (ICCs) indicated the presence of significant discordance across symptom types, with caregivers reporting higher levels of trauma-related difficulties, ICCs = -.21-.22. Older children were more likely to disclose higher levels of anger and sexual concerns than younger children, ßs = .18-.33. Children's gender, race, and relationship to their caregiver were not related to symptom discordance. Further, maternal emotional support and blame/doubt were not associated with caregiver-child concordance for any examined difficulties. Assessment of both caregivers' and children's perceptions of trauma-related symptoms is vital given the likelihood of discordance in child and caregiver reports of symptom levels. Although maternal emotional support and blame/doubt may not be linked to concordance with regard to trauma-related difficulties, child age should further be considered as a potentially important factor in understanding caregiver-child symptom concordance.

Multimodal prediction of pain and functional outcomes 6 months following total knee replacement: a prospective cohort study.

BACKGROUND: Knee osteoarthritis (OA) is among the most common and disabling persistent pain conditions, with increasing prevalence and impact around the globe. In the U.S., the rising prevalence of knee OA has been paralleled by an increase in annual rates of total knee arthroplasty (TKA), a surgical treatment option for late-stage knee OA. While TKA outcomes are generally good, post-operative trajectories of pain and functional status vary substantially; a significant minority of patients report ongoing pain and impaired function following TKA. A number of studies have identified sets of biopsychosocial risk factors for poor post-TKA outcomes (e.g., comorbidities, negative affect, sensory sensitivity), but few prospective studies have systematically evaluated the unique and combined influence of a broad array of factors. METHODS: This multi-site longitudinal cohort study investigated predictors of 6-month pain and functional outcomes following TKA. A wide spectrum of relevant biopsychosocial predictors was assessed preoperatively by medical history, patient-reported questionnaire, functional testing, and quantitative sensory testing in 248 patients undergoing TKA, and subsequently examined for their predictive capacity. RESULTS: The majority of patients had mild or no pain at 6 months, and minimal pain-related impairment, but approximately 30% reported pain intensity ratings of 3/10 or higher. Reporting greater pain severity and dysfunction at 6 months post-TKA was predicted by higher preoperative levels of negative affect, prior pain history, opioid use, and disrupted sleep. Interestingly, lower levels of resilience-related "positive" psychosocial characteristics (i.e., lower agreeableness, lower social support) were among the strongest, most consistent predictors of poor outcomes in multivariable linear regression models. Maladaptive profiles of pain modulation (e.g., elevated temporal summation of pain), while not robust unique predictors, interacted with psychosocial risk factors such that the TKA patients with the most pain and dysfunction exhibited lower resilience and enhanced temporal summation of pain. CONCLUSIONS: This study underscores the importance of considering psychosocial (particularly positively-oriented resilience variables) and sensory profiles, as well as their interaction, in understanding post-surgical pain trajectories.

Ethnic Differences in Experimental Pain Responses Following a Paired Verbal Suggestion With Saline Infusion: A Quasiexperimental Study.

BACKGROUND: Ethnic differences in placebo and nocebo responses are an important, yet underresearched, patient factor that might contribute to treatment disparities. PURPOSE: The purpose of this study was to examine ethnic differences in pain trajectories following a verbal suggestion paired with a masked, inert substance (i.e., saline). METHODS: Using a quasiexperimental design, we examined differences between 21 non-Hispanic Black (NHB) participants and 20 non-Hispanic White (NHW) participants in capsaicin-related pain rating trajectories following a nondirectional verbal suggestion + saline infusion. All participants were told that the substance would "either increase pain sensation, decrease it, or leave it unchanged." A spline mixed model was used to quantify the interaction of ethnicity and time on ratings. RESULTS: There was a significant Ethnicity × Time interaction effect (ß = -0.28, p = .002); NHB individuals reported significantly greater increases in pain following, but not before, the verbal suggestion + saline infusion. Sensitivity analyses showed no change in primary results based on differences in education level, general pain sensitivity, or condition order. CONCLUSIONS: The present results showed ethnic differences in pain response trajectories following a verbal suggestion + saline infusion and suggest that future research rigorously examining possible ethnic differences in placebo/nocebo responses is warranted.

A Preliminary Investigation of the Underlying Mechanism Associating Daily Sleep Continuity Disturbance and Prescription Opioid Use Among Individuals With Sickle Cell Disease.

BACKGROUND: There are emerging data indicating that sleep disturbance may be linked with an increase in opioid use. The majority of sickle cell disease (SCD) patients experience sleep disturbances, which can elevate pain severity and pain catastrophizing, both of which are important predictors of opioid consumption. PURPOSE: We conducted a preliminary investigation on the association between previous night sleep disturbance and short-acting opioid use, as well as the potential mediating roles of pain severity and pain catastrophizing. Because sex is associated with sleep disturbance, pain-related experiences, and opioid use, we also explored the potential moderating role of sex. METHODS: Participants were 45 SCD patients who were prescribed opioids. For 3 months, sleep diaries were collected immediately upon participants' awakening. Daily pain severity, pain catastrophizing, and prescription opioid use measures were collected before bedtime. RESULTS: Multilevel structural equation modeling revealed that wake time after sleep onset (WASO) during the previous night (Time 1) predicted greater short-acting opioid use during the next day (Time 2). Pain severity and pain catastrophizing measured during the next day (Time 2) also mediated the association between the two. Sex moderation analysis showed that the positive association between WASO and pain severity was largely driven by women. CONCLUSION: These findings provide some preliminary evidence as to the mechanism linking sleep continuity disturbance and opioid requirement in SCD patients. Future studies should replicate and extend these findings with clearer temporal information and employing more refined measures of sleep continuity and prescription opioid use in a larger sample.

The Early Impact of COVID-19 on Chronic Pain: A Cross-Sectional Investigation of a Large Online Sample of Individuals with Chronic Pain in the United States, April to May, 2020.

OBJECTIVE: Individuals with chronic pain are uniquely challenged by the COVID-19 pandemic, as increased stress may exacerbate chronic pain, and there are new barriers to receiving chronic pain treatment. In light of this, using a large online sample in the United States, we examined 1) the early impact of COVID-19 on pain severity, pain interference, and chronic pain management; and 2) variables associated with perceived changes in pain severity and pain interference. DESIGN: A cross-sectional study. METHODS: Online survey data for 1,453 adults with chronic pain were collected via Amazon's Mechanical Turk platform. RESULTS: Although a large proportion of participants reported no perceived changes in their pain severity and pain interference since the outbreak, approximately 25-30% of individuals reported exacerbation in these domains. Individuals identifying as Black and of non-Hispanic origin, who experienced greater disruptions in their mood and sleep quality, were more likely to report worsened pain interference. The majority of participants reported engaging in self-management strategies as usual. However, most appointments for chronic pain treatment were either postponed or canceled, with no future session scheduled. Furthermore, a notable proportion of participants had concerns about or difficulty accessing prescription opioids due to COVID-19. CONCLUSIONS: We may expect to see a long-term exacerbation of chronic pain and related interference in functioning and chronic pain management among individuals most impacted by the pandemic. These individuals may benefit from remotely delivered intervention to effectively mitigate COVID-19-related exacerbations in chronic pain and interruptions in face-to-face treatment.

Temporal Association of Pain Catastrophizing and Pain Severity Across the Perioperative Period: A Cross-Lagged Panel Analysis After Total Knee Arthroplasty.

OBJECTIVE: Although numerous studies show that preoperative pain catastrophizing is a risk factor for pain after total knee arthroplasty (TKA), little is known about the temporal course of the association between perioperative pain catastrophizing and pain severity. The present study investigated temporal changes and their dynamic associations between pain catastrophizing and pain severity before and after TKA. DESIGN: A secondary data analysis of a larger observational parent study featuring prospective repeated measurement over 12 months. SETTING: Dual-site academic hospital. SUBJECTS: A total of 245 individuals who underwent TKA. METHODS: Participants completed pain catastrophizing and pain severity questionnaires at baseline, 6 weeks, and 3, 6, and 12 months after TKA. Cross-lagged panel analysis was conducted with structural equation modeling including age, sex, race, baseline anxiety, and depressive symptoms as covariates. RESULTS: Reduction in pain catastrophizing from baseline to 6 weeks after TKA was associated with lower pain severity at 3 months after TKA (standardized ß = 0.14; SE = 0.07, P = 0.046), while reduction in pain severity at 6 weeks after TKA was not associated with pain catastrophizing at 3 months after TKA (P = 0.905). In the chronic postsurgical period (>3 months), pain catastrophizing at 6 months after TKA predicted pain severity at 12 months after TKA (ß = 0.23, P = 0.009) with controlling for auto-correlation and covariates, but not vice versa. CONCLUSIONS: We provide evidence that changes in pain catastrophizing from baseline to 6 weeks after TKA are associated with subsequent pain severity. Future studies are warranted to determine whether targeting pain catastrophizing during the perioperative period may improve clinical outcomes for individuals undergoing TKA.

Missed targets, reaction times, and arousal are related to trait anxiety and attention to pain during an experimental vigilance task with a painful target.

Although hypervigilance may play a role in some clinical pain syndromes, experimental vigilance toward painful stimuli has been studied infrequently. We evaluated vigilance toward pain by using a continuous performance task (CPT), in which subjects responded to moderately intense painful target stimuli, occurring in a train of mildly painful nontargets. We assessed nondetected targets (misses), reaction times (RTs), and psychological activation (tense arousal). During time on task in CPTs of other sensory modalities, there is an increase in misses and RTs (vigilance decrement). We hypothesized that our CPT would influence vigilance performance related to pain, anxiety, and limitation of attentional resources. The results showed a decrement in vigilance over time as misses increased, although RTs were unchanged. While mind-wandering did not influence vigilance performance, intrinsic attention to pain drove both hit RTs and number of misses. This resulted in pain-focused subjects performing worse on the CPT pain task with slower RTs and more misses per block. During the CPT, the change in stimulus salience was related to the change in pain intensity, while pain unpleasantness correlated with tense arousal. CPT performance during experimental vigilance to pain and psychological activation were related to trait anxiety, as measured by the Spielberger State-Trait Anxiety Inventory and neuroticism, as measured by the NEO five factor inventory. Trait anxiety and neuroticism may play important roles in an individual's predisposition to dwell on pain and interpret pain as threatening.NEW & NOTEWORTHY Subjects detected moderately painful target stimuli in a train of mildly painful nontarget stimuli, which resulted in vigilance performance metrics including missed targets, reaction times, and psychological activation. These performance metrics were related to intrinsic attention to pain and trait anxiety. Subjects with high trait anxiety and neuroticism scores, with a predisposition to attend to pain, had greater tense arousal and poorer vigilance performance, which may be important psychological aspects of vigilance to pain.

Experimenter- and Infrared Thermography-Derived Measures of Capsaicin-Induced Neurogenic Flare Among Non-Hispanic White and Black Adults.

OBJECTIVE: Capsaicin is a widely utilized experimental pain stimulus; however, few studies have reported on ethnic differences in pain responses to capsaicin. The present study used infrared thermography to 1) measure differences in capsaicin-induced neurogenic flare between non-Hispanic black (NHB) and non-Hispanic white (NHW) adults and 2) determine the association between neurogenic flare and secondary hyperalgesia. METHODS: Fifty-four participants (NHB N = 28) underwent heat/capsaicin sensitization model procedures. Neurogenic flare was examined using experimenter (i.e., subjective) and thermography (i.e., objective) measurements. A typically nonpainful mechanical punctate probe was used to measure secondary hyperalgesia. RESULTS: Ethnic groups did not significantly differ in age, sex, marital status, or personal income. Although experimenters rated a significantly wider area of capsaicin-related neurogenic flare among NHW compared with NHB participants (F1, 52 = 8.33, P = 0.006), thermography results showed no differences between groups in neurogenic flares (F1, 52 = 0.01, P = 0.93). Further, although NHB individuals reported greater average pain during the capsaicin procedures compared with NHW individuals (NHB = 58.57 [3.67], NHW = 46.46 [3.81]; F2, 51 = 5.19, P = 0.03), the groups did not differ in secondary hyperalgesia (F2, 51 = 0.03, P = 0.86), and ethnicity did not moderate the association between neurogenic flare and secondary hyperalgesia (F3, 50 = 0.24, P = 0.87). CONCLUSIONS: Findings cautiously support the use of infrared thermography over subjective experimenter report when measuring neurogenic inflammation in diverse samples. However, infrared thermography should not be used as a diagnostic tool for pain, given the lack of association between these factors. Future research is warranted to replicate these findings in a larger and more diverse sample to determine accurate neurogenic inflammation measures across other ethnic minority populations.

The moderating role of pain catastrophizing on the relationship between partner support and pain intensity: a daily diary study in patients with knee osteoarthritis.

The objective of this study was to examine the day-to-day associations between partner support, pain catastrophizing and pain intensity in individuals with end-stage knee osteoarthritis. In this microlongitudinal cohort study, participants (N = 124) with end-stage knee osteoarthritis completed baseline measures of trait pain catastrophizing and negative affect. Participants also provided daily diary assessments of partner support, pain catastrophizing and pain intensity for a period of 7 days using a personal digital assistant. Multilevel analyses revealed that day-to-day fluctuations in pain catastrophizing were associated with pain intensity. Data from multilevel analyses indicated that the main effect of partner support was not significantly associated with pain intensity. Results also indicated the interactions between partner support and both trait and state pain catastrophizing were significant, suggesting that both trait and state pain catastrophizing moderated the relationship between daily partner support and pain intensity. That is, on days when participants experienced low levels of partner support, high catastrophizers reported higher levels of pain intensity than low catastrophizers. In the presence of higher levels of partner support, pain intensity did not differ between high and low catastrophizers. These results are consistent with the Communal Coping Model of pain catastrophizing, and highlight the interpersonal context within which pain catastrophizing impacts pain outcomes. These findings also suggest that future interventions designed to specifically target the dynamic between pain catastrophizing and partner support may improve pain outcomes in individuals with end-stage knee OA.

Does Maternal Support Mediate or Moderate the Relationship between Sexual Abuse Severity and Children's PTSD Symptoms?

Maternal support and abuse severity are often considered to be vital factors in predicting children's functioning following childhood sexual abuse (CSA); however, much of the prior research has examined support and abuse severity as main effects, without consideration of how these factors may interrelate to predict children's post-CSA functioning. Further, even though mediators and moderators are conceptually distinct, maternal support has been theorized to be both a mediator and a moderator of symptoms, and it is unclear if support acts as either among sexually abused children. The aim of the present study was to investigate whether caregiver-reported maternal support mediates or moderates the relationships between sexual abuse severity and children's trauma-related symptoms. The study included 235 treatment-seeking children ages 3-16 (M = 8.85, SD = 3.77) and their non-offending mothers. Contrary to expectations, caregiver-rated maternal support did not mediate nor moderate the relationship between abuse severity and children's symptoms (range r2 =.002 -.03). Caregiver-rated maternal support may play a small role in mitigating sexually abused children's trauma symptoms. Irrespective of abuse severity, children with less supportive mothers may not be at heightened risk for experiencing higher levels of trauma-related difficulties.

Quantitative sensory testing in children with sickle cell disease: additional insights and future possibilities.

Quantitative sensory testing (QST) is used in a variety of pain disorders to characterize pain and predict prognosis and response to specific therapies. In this study, we aimed to confirm results in the literature documenting altered QST thresholds in sickle cell disease (SCD) and assess the test-retest reliability of results over time. Fifty-seven SCD and 60 control subjects aged 8-20 years underwent heat and cold detection and pain threshold testing using a Medoc TSAII. Participants were tested at baseline and 3 months; SCD subjects were additionally tested at 6 months. An important facet of our study was the development and use of a novel QST modelling approach, allowing us to model all data together across modalities. We have not demonstrated significant differences in thermal thresholds between subjects with SCD and controls. Thermal thresholds were consistent over a 3- to 6-month period. Subjects on whom hydroxycarbamide (HC) was initiated shortly before or after baseline testing (new HC users) exhibited progressive decreases in thermal sensitivity from baseline to 6 months, suggesting that thermal testing may be sensitive to effective therapy to prevent vasoocclusive pain. These findings inform the use of QST as an endpoint in the evaluation of preventative pain therapies.