European Journal of Pain最新文献

Background

Psychosocial aspects underlie and maintain persistent pain. Emotions have emerged as a target for psychological interventions in pain management. Our aim was to better understand the relationship between emotions and bodily sensations, including pain sensitivity, using two new approaches.

Methods

110 patients with confirmed endometriosis and 110 age- and gender-matched pain-free controls completed computer-based Bodily Sensation Maps for six basic emotions and a neutral emotional state, tactile, nociceptive, and hedonic sensitivities, as well as current and persistent pain. All participants also evaluated their current emotional experience of six basic emotions, depression, and anxiety, and answered the Brief Pain Inventory questionnaire; 102 endometriosis patients also answered the Multidimensional Assessment of Interoceptive Awareness questionnaire.

Results

Endometriosis patients coloured in significantly larger painful areas on body maps and greater sensitivities to both nociceptive and hedonic sensations than did the pain-free controls. The endometriosis patients reported more current fear than controls but did not differ from controls in the colouring in of basic emotions on the body maps. Emotional awareness was associated with higher pain intensity, and with more colouring for persistent pain. More trusting was associated with less affective interference and with less colouring for current pain. Less worrying and more trusting were associated with more colouring for hedonic sensitivity.

Conclusions

Bodily sensation maps and multidimensional assessment of interoceptive awareness provide important information about the interface of emotions and pain. Our results suggest that a less worrying and a more trusting nature have a protective role in pain interference.

Significance

Bodily emotions and interoceptive awareness associate with sensitivity to pain and should be addressed when targeting emotions in pain management.

Background

This randomised controlled feasibility study aimed to evaluate the feasibility of a main study and provide a first assessment of whether the exercise-induced hypoalgesia (EIH) response differs depending on the training modalities in people with knee osteoarthritis (OA) and whether it can be enhanced by education about pain.

Methods

People with knee OA (n = 36, 60 ± 11 years, WOMAC total 51.7 ± 36.6) were randomly assigned to receive lower body resistance training (RTL), upper body resistance training (RTU), or aerobic training (AET). Each participant performed three training sessions (t1, t2, t3) separated by 1 week, and education about pain and EIH after t2. Pressure pain threshold (PPT) was measured at six sites before (PPT0), immediately after (PPT1), and 30 min after (PPT30) each training session. Feasibility was assessed using indicators for practicability, acceptance, and safety.

Results

This study's procedures were deemed feasible, including high acceptance of the measurement method and educational information, well-tolerated training exercises, and a dropout rate of 8%. In each group and after each session, an EIH response could be detected at PPT1 and PPT30 (Cohen's d ≥ 0.5 to ≥ 0.8). At most measurement sites, effect sizes tended to be largest after RTL and at t3.

Conclusion

Progression to a larger study is warranted. RTL, but also AET and RTU may induce EIH in people with knee OA. Pain education might have a useful supporting function, but its effect would need to be determined in a study design using a control group that receives training and no education.

Significance Statement

Lower body resistance training, but also aerobic training and upper body resistance training may induce hypoalgesia in people with knee osteoarthritis. Being less pain sensitive after performing various exercise training modalities provides a significant benefit and can improve the quality of life of people with knee OA. If confirmed in a larger study, these findings might also allow better consideration of patients' individual preferences and potential comorbidities for exercise prescription.

Trial Registration

German Clinical Trials Register: DRKS00024480

Background

The COVID-19 pandemic disrupted healthcare systems worldwide, including the postponement of non-urgent care and reallocation of resources toward COVID-19 patients. The aim of this study was to assess the impact of the first Dutch COVID-19 lockdown on the initiation of new analgesic prescriptions.

Methods

This study analysed dispensing data from 1890 Dutch pharmacies, covering approximately 96% of the population (5.46 million patients). The number of first-time prescription analgesics dispensed (ATC2 N02 class, e.g., opioids, anilides) was compared between the first halves of 2019 and 2020. First-time users were defined as patients who had not received the drug in the preceding year. Data were stratified by age group (children, adolescents, adults, elderly), sex and time periods: weeks 1–11 (pre-lockdown 2020), 12–19 (lockdown) and 20–26 (post-lockdown).

Results

The total number of first-time dispensed analgesic drugs was significantly lower in 2020 (367,094) than in 2019 (388,973, p = 0.021), with a notable reduction occurring during the lockdown period (p = 0.003). Significant declines in first-time dispensed analgesic drugs were observed among adolescents and adults during lockdown (p < 0.001), particularly among females. In contrast, no significant changes were found among children and the elderly. The number of first-time dispensed analgesic drugs during the pre- and post-lockdown periods was comparable between the 2 years.

Conclusion

Delayed healthcare during the lockdown was associated with a decrease in first-time dispensed analgesic drugs, especially among adolescents and adults. This may indicate untreated pain or increased reliance on over-the-counter alternatives during this period.

Significance Statement

This Nationwide Dutch study showed a significant decline in first-time dispensed analgesic drugs during the first lockdown period of the COVID-19 pandemic, especially among adolescents and adults. This may indicate untreated pain due to delayed healthcare or an increased reliance on over-the-counter alternatives during this period.

Background

Studies demonstrate that pain sensitization, epigenetic mechanisms, inflammation, and psychological factors might be predictive of treatment outcomes. Anti-inflammatory therapy is recommended, but efficacy varies among patients. This study aimed to utilise machine learning to predict the analgesic responses of 3-week NSAID plus paracetamol therapy using pre-treatment assessments of pain sensitivity, inflammation, microRNA, and psychological factors.

Methods

Patients (n = 101) underwent 3-week combined NSAID plus paracetamol therapy. Pain sensitivity using cuff algometry, Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale, EQ-5D-3L scale, and blood samples were collected before therapy. Pain relief was assessed by the Knee Injury and Osteoarthritis Outcome Score pain subscale, before and after therapy. Inflammatory biomarkers were analysed using Olink, and microRNA using Next-Generation RNA Sequencing. Data Integration Analysis for Biomarker discovery using Latent cOmponents (DIABLO) was utilised to integrate the pre-treatment data and explain the analgesic effect.

Results

DIABLO model identified 30 significant variables across the 4 domains. After cross-validation, model performance showed an area under the precision-recall curve of 85%, sensitivity of 83%, specificity of 87%, and balanced accuracy of 85%.

Conclusions

This study utilises a machine learning algorithm, based on pain sensitization, epigenetics, inflammatory response, and psychological factors, to predict analgesic response in osteoarthritis patients. The study demonstrates that incorporating multiple factors into a model enhances its performance, enabling the identification of patients who will benefit from therapy, advancing personalised pain management.

Significance Statement

In this study, a machine learning algorithm, based on pain sensitization, epigenetic mechanisms, inflammatory response, and psychological factors, predicts analgesic response in osteoarthritis patients with 84% accuracy.

Trial Registration

ClinicalTrials.gov identifier: NCT02967744

Purpose

This study investigates the association of sociodemographic factors and comorbidities with labour market affiliation among patients with non-malignant chronic pain treated at multidisciplinary pain centres in Denmark.

Methods

This registry-based cohort study used data from the nationwide Danish Civil Registration System and Danish National Patient Registry. Patients treated at multidisciplinary pain centres in 2013–2017 were included. Labour market affiliation was assessed 5 years before and 2 years after treatment and at treatment initiation (baseline). Sequence and logistic regression analyses were used to identify associations.

Results

2375 patients (median age 47 years, female 64%, comorbidity: Mean Charlson's comorbidity score: 0.88, affective disorder: 45%, anxiety disorder: 37.0%, personality disorder: 7.8%) were included. At treatment initiation, only 34.2% of patients were employed, compared to 58.6% 5 years before treatment. Sequence analysis revealed that most patients remained in or transitioned to a ‘no labour market affiliation’ state. Factors significantly associated with labour market affiliation across timepoints included age (adjusted odd ratio [aOR] and 95% confidence interval [CI]_{age 56–65} = 0.51 [0.38–0.69]), marital status (aOR_cohabitant = 1.58 [1.30–1.92]), education level (aOR_high = 4.56 [3.51–5.93]), immigrant status (aOR_non-western = 0.35 [0.26–0.45]) and psychiatric comorbidities (aOR_{affective disorders} = 0.67 [0.56–0.87]).

Conclusion

Patients with high-impact, treatment-resistant chronic pain face early labour market detachment, highlighting the need for timely, equitable interventions to support employment, especially among vulnerable groups.

Significance Statement

The study offers new evidence on how socioeconomic and psychiatric comorbid vulnerabilities shape long-term labour market affiliation before relevant multidisciplinary treatment is initiated and suggests that key intervention opportunities for at-risk patients may be missed under current practice.

Background

Exercise-induced hypoalgesia (EIH) describes an acute reduction in pain following exercise. Individuals with low back pain (LBP) demonstrate variable EIH responses, such as increased pain sensitivity (hyperalgesia). Pain phenotyping, classifying individuals with pain sensitivity and psychological characteristics, may explain this variability. LBP phenotypes were classified using pain sensitivity, psychological variables, and EIH response to dynamic resistance exercise.

Methods

In this observational cohort study, 78 individuals with LBP (mean age = 21.7 ± 2.6 years, 59% female) completed clinical pain ratings (Numeric Pain Rating Scale [NPRS]), temporal summation (TS), conditioned pain modulation (CPM), psychological questionnaires (Fear-Avoidance Beliefs Questionnaire-Physical Activity subscale [FABQ-PA]), and a 45-degree Roman chair back extension exercise. Pressure pain threshold (PPT) pre- and post-exercise determined EIH. Ward's hierarchical cluster analysis was performed with five variables (NPRS, TS, CPM, FABQ-PA, EIH). One-way ANOVA examined differences in demographic, clinical, and psychosocial factors by cluster.

Results

Three distinct clusters emerged: (1) efficient pain modulation with low fear-avoidance and high EIH (n = 40); (2) impaired pain modulation with moderate fear-avoidance and hyperalgesia (n = 19); (3) moderate pain modulation with high fear-avoidance and moderate EIH (n = 19). Clusters differed significantly by age (p = 0.02, η_p² = 0.098), disability (p = 0.004, η_p² = 0.138), psychosocial burden (p = 0.03, η_p² = 0.086), and pain catastrophizing (p = 0.03, η_p² = 0.09).

Conclusion

Individuals with LBP exhibit heterogeneous pain phenotypes. Psychological factors may diminish EIH, and impaired modulation may produce hyperalgesia post-exercise. Identifying pain phenotypes may enhance personalised rehabilitation strategies, optimising interventions for LBP.

Significance

This study provides novel evidence that biopsychosocial phenotypes influence pain responses to resistance exercise, offering a potential pathway to personalised rehabilitation for LBP.

Background

Migraine is a neurovascular disease associated with significant morbidity and disability, but its underlying pathophysiology remains elusive. Functional alterations within the brain are frequently observed in individuals with migraine, whereas structural changes are less frequently documented. This study was primarily designed to investigate topological abnormalities in brain structural networks in patients with migraine using structural magnetic resonance imaging.

Methods

Graph theoretical analysis was used to compare global and regional topological properties of grey matter structural networks in 37 migraine patients and 44 age-, gender-, and education-matched healthy controls. Structural correlation networks were constructed for both groups on the basis of measurements of grey matter volume.

Results

A statistically significant difference was observed in the scores of Self-rating Anxiety Scales (SAS) and Self-rating Depression Scales (SDS) between migraine patients and healthy controls. The brain networks of patients exhibited significantly increased path length, decreased clustering coefficient, and small-worldness at the global level. At the regional level, brain regions with changes in node degree/betweenness centrality in migraine patients were predominantly located in the left cuneus, the left fusiform gyrus, the left precuneus, the right precentral gyrus, the right middle frontal gyrus, and the bilateral lingual gyrus.

Conclusion

The findings of this research indicate that the topological organisation is less efficient in individuals who experience migraine. This may provide new insight into the pathogenesis of migraine from a structural perspective.

Trial Registration: Chinese Clinical Trial Registry, ChiCTR2000033995

Significance

The present study addresses the central pathogenesis of migraine and shows at a structural level that global brain properties are altered in migraine patients and that regional properties of specific brain regions also show abnormalities. This provides new ideas and an objective basis for the future diagnosis and treatment of migraine.