Greater interruption of visual processing and memory encoding by visceral than somatic pain in healthy volunteers - An fMRI study.

Visceral pain is regarded as more salient than somatic pain. It has greater affective and emotional components, i.e., it elicits higher levels of pain-related fear and is perceived as more unpleasant than somatic pain. In this fMRI study, we examined the neural effects of painful visceral as compared to painful somatic stimulation on visual processing and memory encoding in a visual categorization and surprise recognition task in healthy volunteers. During the categorization task, participants received either rectal distensions or heat stimuli applied to the forearm, with stimuli being individually matched for unpleasantness. Behaviorally, visceral pain reduced memory encoding as compared to somatic pain (Kleine-Borgmann et al., 2021). Imaging analyses now revealed that visceral pain was associated with reduced activity (i.e., greater pain-related interruption) in neural areas typically involved in visual processing and memory encoding. These include the parahippocampal gyrus, fusiform gyrus, striatum, occipital cortex, insula, and the amygdala. Moreover, reduced engagement of the lateral occipital complex during visual categorization under visceral pain was associated with higher visceral pain-related fear. These findings obtained in healthy volunteers shed light on the neural circuitry underlying the interruptive effect of visceral pain and pave the way for future studies in patient samples.

[Results of a pilot study on the role of therapy expectation in interdisciplinary multimodal pain therapy for chronic back pain]. / Ergebnisse einer Pilotstudie zur Rolle der Therapieerwartung bei der interdisziplinären multimodalen Schmerztherapie bei chronischem Rückenschmerz.

BACKGROUND: Chronic low back pain is a serious persistent illness with profound personal and socioeconomic impact. Interdisciplinary multimodal pain therapy (IMPT) is one of the few evidence-based treatment options for chronic pain. Although it is known that pain perception, as well as its chronification and treatment are affected by patient expectations, only few clinical interventions or guidelines on how to modulate these effects exist. OBJECTIVES: The aim of this study was to demonstrate the impact of expectancy as a predictor for pain and related outcomes. To this end, we will present explorative pilot data from an observational cohort at our clinic. METHODS: The study shows preliminary data of a prospective longitudinal observational study of up to 41 chronic back pain patients who followed an IMPT at the back pain center in Essen. Data were collected at admission (T0), at discharge (T1), and 3 months after discharge (T2). Primary outcomes were pain intensity and disability. Additionally, we measured treatment expectancy at admission. We used linear regression to analyze the impact of pretreatment expectancy on the primary outcome measures. RESULTS: IMPT led to a significant improvement in pain intensity and disability. The effect on pain intensity was stable over three months after discharge and disability declined even further. Expectancy was a significant predictor of improvement in pain intensity and explained approximately 15% of the variance. DISCUSSION: Expectancy is an important predictor of treatment outcome in IMPT. In clinical practice, valid methods should therefore be established to reduce negative and promote positive expectations.

Learning by observing: a systematic exploration of modulatory factors and the impact of observationally induced placebo and nocebo effects on treatment outcomes.

Introduction: Observational learning (OL) refers to learning through observing other people's behavior. OL has been suggested as an effective and simple tool to evoke treatment expectations and corresponding placebo and nocebo effects. However, the exact mechanisms by which OL shapes treatment outcomes, its moderating factors and possible areas of application remain unclear. We thus reviewed the existing literature with two different literature searches to answer the following questions: Which influencing factors contribute to OL-induced placebo and nocebo effects (in healthy volunteers and patients) and how large are these effects (search 1)? In which medical fields has OL been used so far to modulate treatment expectancy and treatment outcomes in patients, their caregivers, and at-risk groups (search 2)? We also aimed to explore whether and how the assessment of treatment expectations has been incorporated. Methods: We conducted two independent and comprehensive systematic literature searches, both carried out on September 20, 2022. Results: We identified 21 studies that investigated OL-mediated placebo and nocebo effects for pain and itch, the (placebo) efficacy of sham treatment on anxiety, and the (nocebo) induction of medication side effects (search 1). Studies showed that OL can efficiently induce placebo and nocebo effects across different presentation modes, with medium effect sizes on average: placebo effects, d = 0.79 (range: d = -0.36-1.58), nocebo effects, d = 0.61 (range: d = 0.04-1.5). Although several moderating factors have been investigated, their contribution to OL-induced effects remains unclear because of inconsistent results. Treatment expectation was assessed in only four studies. Regarding medical applications of OL (search 2), we found 12 studies. They showed that OL was effectively applied in preventive, therapeutic and rehabilitative interventions and that it was mainly used in the field of psychosomatics. Discussion: OL effects on treatment outcomes can be both positive and negative. Future research should investigate which individuals would benefit most from OL and how OL can be implemented most effectively to induce placebo and avoid nocebo effects in clinical settings. Systematic review registration: This work was preregistered at the Center for Open Science as open-ended registration (doi: 10.17605/OSF.IO/FVHKE). The protocol can be found here: https://archive.org/details/osf-registrations-fvhke-v1.

Setting the stage for pain relief: how treatment setting impacts interdisciplinary multimodal pain treatment for patients with chronic back pain.

ABSTRACT: While interdisciplinary multimodal pain treatment (IMPT) is an effective treatment option for chronic low back pain, it is usually accomplished as an inpatient treatment incurring substantial healthcare costs. Day hospital IMPT could be a resource-saving alternative approach, but whether treatment setting is associated with differences in treatment outcomes has not yet been studied. In a retrospective matched cohort study including data from N = 595 patients diagnosed with chronic back pain and undergoing IMPT at the back pain center in Essen, Germany, we investigated the association between treatment setting (ie, inpatient or day patient of an otherwise identical IMPT) and pain intensity, disability, and self-efficacy after treatment. Outcomes were assessed by questionnaires used in clinical routine, collected at pre-IMPT, post-IMPT, and at 3-, 6-, and 12-month follow-up. The results indicate that day patients showed greater improvements in pain-related disability at 3-month post-IMPT (d = 0.74) and in pain intensity at 6-month post-IMPT (d = 0.79), compared to a matched sample of inpatients. Moreover, day patients achieved higher scores in pain-related self-efficacy at discharge, 3- and 6-month post-IMPT (d = 0.62, 0.99, and 1.21, respectively) and reported fewer incapacity-for-work days than inpatients at 6-month post-IMPT (d = 0.45). These data suggest that day hospital IMPT can be as effective as inpatient treatment and might even be more effective for the less afflicted patients. Further research regarding treatment setting and indication could guide optimized and cost-efficient treatments that are more closely tailored to the individual patient's needs.

Needs and Demands for eHealth Pain Management Interventions in Chronic Pain Patients.

Although chronic pain is a global health problem, the current care situation is often inadequate. eHealth offers many advantages as an additional option for treating chronic pain. Yet, an intervention's efficacy can only be fully exhausted if patients intend to use it. This study aims to identify the needs and demands of patients with chronic pain regarding intervention concepts and frameworks to develop specifically tailored eHealth pain management interventions. A cross-sectional study was conducted, including 338 individuals with chronic pain. Within the cohort, a distinction between a high- and a low-burden group was made. Respondents generally preferred a permanently accompanying mobile app, but the preferred content varied with group. According to the majority, interventions should be made available on smartphones, offer sessions once per week with a duration from 10 to 30 min, and be recommended by experts. These results can provide the basis for future eHealth pain management interventions tailored to the patients' needs and demands.

Impact of the COVID-19 pandemic on patients with chronic pain in Germany: Associations with expectations and control beliefs.

BACKGROUND: While the COVID-19 pandemic is affecting people's well-being worldwide, it may place a particularly high burden on people with chronic pain, as pain is known to be influenced by societal and psychological conditions. METHODS: In this observational study, we conducted telephone interviews with 196 patients with chronic pain to assess the impact of the pandemic on various aspects of their pain and everyday life. The initial interviews were conducted between April and May 2020 and were followed up by a second interview between August and December 2020. RESULTS: A substantial percentage of patients (39% at the first and 32% at the second interview) reported an increase in pain intensity due to the pandemic. Exploratory analyses revealed that patients who already suffered from greater pain and who experienced greater restrictions due to the pandemic were more likely to express pain worsening. Psychological factors such as negative expectations about the development of their pain and pain treatment and a high external locus of control were also associated with increases in pain. CONCLUSIONS: These findings illustrate the complexity of chronic pain, suggesting that not only the impact of the pandemic on various areas of life but also the severity of the pain-symptoms themselves and psychological factors influence the course of patients' symptoms during the pandemic. SIGNIFICANCE: This study underlines the importance of psychosocial factors in chronic pain and demonstrates that the societal and psychological impact of the COVID-19 pandemic can affect patients' pain and their ability to cope with it. The extent to which patients experience pain aggravation seems to interact with other psychological factors such as pain expectations and control beliefs.

Determining the Influencing Factors on Acceptance of eHealth Pain Management Interventions Among Patients With Chronic Pain Using the Unified Theory of Acceptance and Use of Technology: Cross-sectional Study.

BACKGROUND: Chronic pain is a complex disease with high prevalence rates, and many individuals who are affected do not receive adequate treatment. As a complement to conventional therapies, eHealth interventions could provide many benefits to a multimodal treatment approach for patients with chronic pain, whereby future use is associated with the acceptance of these interventions. OBJECTIVE: This study aims to assess the acceptance of eHealth pain management interventions among patients with chronic pain and identify the influencing factors on acceptance. A further objective of the study is to evaluate the viability of the Unified Theory of Acceptance and Use of Technology (UTAUT) model and compare it with its extended version in terms of explained variance of acceptance. METHODS: We performed a cross-sectional web-based study. In total, 307 participants with chronic pain, as defined according to the International Association for the Study of Pain criteria, were recruited through flyers, posters, and web-based inquiries between December 2020 and July 2021. In addition to sociodemographic and medical data, the assessment included validated psychometric instruments and an extended version of the well-established UTAUT model. For statistical analyses, group comparisons and multiple hierarchical regression analyses were performed. RESULTS: The acceptance of eHealth pain management interventions among patients with chronic pain was overall moderate to high (mean 3.67, SD 0.89). There was significant difference in acceptance among age groups (W=9674.0; r=0.156; P=.04). Effort expectancy (ß=.37; P<.001), performance expectancy (ß=.33; P<.001), and social influence (ß=.34; P<.001) proved to be the most important predictors of acceptance. The extended UTAUT (including the original UTAUT factors as well as sociodemographic, medical, and eHealth-related factors) model explained 66.4% of the variance in acceptance, thus supporting the viability of the model. Compared with the original UTAUT model (performance expectancy, effort expectancy, and social influence), the extended model explained significantly more variance (F25,278=1.74; P=.02). CONCLUSIONS: Given the association between acceptance and future use, the knowledge of the influencing factors on acceptance should be used in the development and promotion of eHealth pain management interventions. Overall, the acceptance of eHealth pain management interventions was moderate to high. In total, 8 predictors proved to be significant predictors of acceptance. The UTAUT model is a valuable instrument for determining acceptance as well as the factors that influence acceptance of eHealth pain management interventions among patients with chronic pain. The extended UTAUT model provided the greatest predictive value for acceptance.

Transfer in Motor Sequence Learning: Effects of Practice Schedule and Sequence Context.

Transfer (i.e., the application of a learned skill in a novel context) is an important and desirable outcome of motor skill learning. While much research has been devoted to understanding transfer of explicit skills the mechanisms of skill transfer after incidental learning remain poorly understood. The aim of this study was to (1) examine the effect of practice schedule on transfer and (2) investigate whether sequence-specific knowledge can transfer to an unfamiliar sequence context. We trained two groups of participants on an implicit serial response time task under a Constant (one sequence for 10 blocks) or Variable (alternating between two sequences for a total of 10 blocks) practice schedule. We evaluated response times for three types of transfer: task-general transfer to a structurally non-overlapping sequence, inter-manual transfer to a perceptually identical sequence, and sequence-specific transfer to a partially overlapping (three shared triplets) sequence. Results showed partial skill transfer to all three sequences and an advantage of Variable practice only for task-general transfer. Further, we found expression of sequence-specific knowledge for familiar sub-sequences in the overlapping sequence. These findings suggest that (1) constant practice may create interference for task-general transfer and (2) sequence-specific knowledge can transfer to a new sequential context.