Scandinavian Journal of Pain最新文献

Objectives: In the professional environment, low back pain (LBP) is a multifactorial symptomatology, despite scientific and technological advances in the design and the arrangement of increasingly ergonomic workstations. Teachers are not exempt from this risk, due to prolonged sitting or standing. In light of this, this study aimed to estimate LBP prevalence among teachers in Southern Tunisia and to identify their determinants.

Methods: It was a cross-sectional study including a representative sample of teachers from secondary, middle, and primary schools in Sfax, Tunisia, conducted during the period March-April 2021. LBP intensity was assessed using a visual analog scale from 1 to 10. A severe LBP was defined as VAS≥7.

Results: Among the participants, 292 teachers were females (55.6 %). The median age was 48 years (Interquartile Range (IQR)=[41-53] years). Overall, 377 teachers had a severe LBP, with a global prevalence of 71.8 %. Multivariate analysis showed that independent determinants of LBP among teachers were female gender (Adjusted Odds Ratio (AOR)=2.81;p<0.001), age ≥30 (AOR=5.68;p=0.009), chronic diseases (AOR=2.52;p<0.001), working at primary schools (AOR=1.75;p=0.033), working for ≥4 h per day (AOR=2.41;p=0.005), inadequate ergonomic conditions at work (AOR=1.78;p=0.008) and distance home-school ≥10 km (AOR=2.27;p=0.003).

Conclusions: This study demonstrated that LBP among teachers was alarmingly high. Different individual, ergonomic, and occupational factors were predictors of this symptom. Thus, development of rational strategies for LBP prevention among teachers and the improvement of working conditions are urgently needed.

Objectives: Pain and itch share similar neuronal networks; hence, it is difficult to explain why opioids can relieve pain but provoke itching. The present human volunteer study aimed to investigate the similarities and differences in responses to experimentally provoked pain and itching to explore the underlying fundamental mechanisms.

Methods: Twenty-four healthy volunteers were enrolled in this single-center, randomized, double-blind, placebo-controlled, parallel-group trial. Three volar forearms and two mandibular areas were marked, and participants randomly received morphine (20 mg) or identical placebo tablets. Heat, cold, and pressure pain thresholds, and vasomotor responses were assessed at baseline and after oral morphine administration. Itch provocations were induced by intradermal application of 1 % histamine or a topical cowhage (non-histaminergic itch) to a marked area of the skin. The participants were subsequently asked to rate their itching and pain intensities. The assessments were repeated for all marked areas.

Results: Morphine caused analgesia, as assessed by the significant modulation of cold and pressure pain thresholds (p<0.05). There were no significant differences in histaminergic or non-histaminergic itch or pain intensity between the morphine and placebo groups. Superficial blood perfusion (vasomotor response) following histamine provocation was significantly increased by morphine (p<0.05) in both areas. No correlation was found between the provoked itch intensity and analgesic efficacy in any area or group.

Conclusions: Oral administration of morphine caused analgesia without modulating itch intensities but increased neurogenic inflammation in response to histamine, suggesting that different opioid mechanisms in histaminergic and non-histaminergic neurons evoke neurogenic inflammation.

Objectives: Studies suggest that a range of pain mechanisms, such as poor quality of sleep, perceived stress, pain catastrophizing or pain sensitivity, are likely to enhance clinical pain. Animal studies suggest that these pain mechanisms can be modulated by increasing physical activity, but human data are needed to support this hypothesis. This exploratory study aimed to investigate the changes in pain mechanisms after a simple self-directed walking program of 8-weeks. Additionally, this exploratory study investigated the interaction between changes over time in assessments of poor quality of sleep, perceived stress, pain catastrophizing or pain sensitivity and how these changes interacted with each other.

Methods: This prospective cohort study included 30 healthy subjects who were assessed at baseline and 4- and 8-weeks after initiating the walking program (30 min walking/day for 8 weeks). Self-report outcomes included: Pain Catastrophizing Scale (PCS), the Perceived Stress Scale (PSS) and Pittsburgh Sleep Quality Index. Pressure pain thresholds, temporal summation of pain and conditioned pain modulation (CPM) were assessed using cuff algometry.

Results: Twenty-four subjects completed all the visits (age: 42.2, SD: 14.9, 16 females). PCS and PSS significantly decreased at the 8-week's visit compared to baseline (p<0.05). No significant differences were seen for an improvement in quality of sleep (p=0.071) and pain sensitivity (p>0.075) when comparing the 8-week's visit to the baseline visit. Changes in pain mechanisms comparing baseline and 8-weeks data were calculated and regression analyses found that an improvement in PCS was associated with an improvement in CPM (R²=0.197, p=0.017) and that a higher adherence to the walking program was associated with a larger improvement in PCS (R²=0.216, p=0.013).

Conclusions: The current exploratory study indicates that a simple self-directed walking program of 8-weeks can improve pain catastrophizing thoughts, perceived stress. Higher adherence to the walking program were associated with an improvement in pain catastrophizing and an improvement in pain catastrophizing was associated with an increase in conditioned pain modulation.

Objectives: Chronic musculoskeletal pain (CMP) is a common condition, often consulted in general practice. Our previous study identified research priorities among people with CMP using a broad recruitment strategy. It is unclear whether these research priorities reflect specific settings, including the population in general practice. Potential dissimilarities may have important implications for future research. Therefore, the study aims to explore potential differences between the previously established research priorities compared to priorities of people with CMP consulting general practice.

Methods: Eighty-eight people living with CMP (51 females/37 males) from four regions of Denmark were recruited when they consulted their general practitioner. Participants were presented to an online survey and asked to prioritise predefined research themes (n=14) and research questions (n=38). The prioritisations were summarised into a Top-10 research priorities and compared the Top-10 from our previous study.

Results: Treatment (n=57), diagnosis (n=46), cross-sectoral management (n=39) and influence on daily life (n=39) were the most selected research themes. The most prioritised research questions regarded the effectiveness of treatments and cross-sectoral management, improving diagnostic approaches and how pain affects the individuals' mental state. Four out of ten research questions aligned with our previous Top-10.

Conclusions: Our study identified several differences in research priorities between people living with CMP from the general population and from general practice. These findings highlight the needs for investigating how different settings influence research prioritisation. This adds important knowledge for researchers and policymakers focusing on future research within the management of CMP.

Objectives: Smerteinfo.dk is a freely accessible Danish website containing research-based, up-to-date knowledge on chronic pain, written in lay language, with a focus on information, guidance and self-management tools, developed in collaboration between health professionals and persons with high-impact chronic pain. This mixed-method study explored experiences, perceived usability, and challenges of Smerteinfo among patients with high-impact chronic pain.

Methods: Semi-structured interviews enabling thinking-aloud and participant observation while using Smerteinfo were performed in 11 patients with high-impact chronic pain. Survey data were collected three months after being invited to use Smerteinfo among 200 patients on waiting-list at a Pain Center in Denmark.

Results: Three themes captured the depth and variation in patterns of experiences, usability and challenges using Smerteinfo during interviews: 1) Appreciated easy access to new knowledge yet strived for more personalized information, 2) Experienced incentives as well as challenges when navigating the website, and 3) Suggested earlier introduction to the website. Challenges concerned the unknown update frequency of the website, information consisting of mostly text and many links, lack of material to improve self-management and too general information. Survey data revealed that 87 % found the language in the articles easy to understand and 73 % could recognize themselves and their challenges in the articles. A proportion of the respondents reported improved understanding of their pain condition (56 %), improved coping (33 %), and that they had made changes in their everyday life after reading on the website (33 %).

Conclusions: Patients with high-impact chronic pain found Smerteinfo valuable. The results suggest attention towards spreading knowledge of the website to general practitioners, who could introduce the site at an earlier stage of illness. Continuously improving the site and expand the applicable tools based on scientific evidence and in collaboration with end-users are crucial to ensure the usability of the website in the future.

Objectives: Intrathecal morphine pump (ITMP) infusion therapy is efficient in managing chronic pain refractory to standard treatment. This study evaluates pain relief and improvement of quality of life in chronic pain patients after intrathecal morphine pump implantation for treatment of persistent pain after lumbar spinal fusion surgery and lumbar spinal decompression alone.

Methods: Forty three chronic pain patients that received an ITMP at our department between 2009 and 2019 were retrospectively analyzed divided into 2 cohorts (lumbar spinal fusion surgery and lumbar spinal decompression alone). Pain intensity was evaluated using the numeric rating scale (NRS), quality of life was assessed by EQ-5D-3L, mental health was assessed by Beck Depression Inventory (BDI-V), and Pain Catastrophizing Scale (PCS). Morphine dosage was assessed over time. Data was collected preoperatively, 6 and 24 months postoperatively. Statistical analysis was performed using Friedman's analysis of variance to evaluate the development of NRS, PCS, BDI and EQ-5D-3L over time and Mann-Whitney-U-test for the differences between these parameters in the different cohorts. A two-sided p-value <0.05 was considered statistically significant.

Results: Median age was 64 years (IQR^25-75 56-71 years). NRS, EQ-5D-3L, BDI-V, and PCS showed a significant overall improvement after 6 and 24 months compared to baseline data (p<0.001). No statistically significant differences between patients with lumbar spinal fusion surgery and lumbar spinal decompression alone were seen. Furthermore, no statistically significant differences for age and gender were seen. The initially administered median morphine dosage was significantly higher in the fusion group (3.0 mg/day; IQR^25-75 1.5-4.2 mg/day) compared to the decompression-alone group (1.5 mg/day; IQR^25-75 1.0-2.6 mg/day); (p=0.027).

Conclusions: This retrospective study showed that ITMP have a major long-term impact on pain relief, improve the quality of life, psychological distress, as well as pain catastrophizing in patients with chronic pain following lumbar spinal surgery independent of the previous surgical procedure. After ITMP implantation initial median morphine dosage seems to be significantly higher after spinal fusion compared to decompressive surgery alone.

Objectives: The Automatic Pain Assessment (APA) relies on the exploitation of objective methods to evaluate the severity of pain and other pain-related characteristics. Facial expressions are the most investigated pain behavior features for APA. We constructed a binary classifier model for discriminating between the absence and presence of pain through video analysis.

Methods: A brief interview lasting approximately two-minute was conducted with cancer patients, and video recordings were taken during the session. The Delaware Pain Database and UNBC-McMaster Shoulder Pain dataset were used for training. A set of 17 Action Units (AUs) was adopted. For each image, the OpenFace toolkit was used to extract the considered AUs. The collected data were grouped and split into train and test sets: 80 % of the data was used as a training set and the remaining 20 % as the validation set. For continuous estimation, the entire patient video with frame prediction values of 0 (no pain) or 1 (pain), was imported into an annotator (ELAN 6.4). The developed Neural Network classifier consists of two dense layers. The first layer contains 17 nodes associated with the facial AUs extracted by OpenFace for each image. The output layer is a classification label of "pain" (1) or "no pain" (0).

Results: The classifier obtained an accuracy of ∼94 % after about 400 training epochs. The Area Under the ROC curve (AUROC) value was approximately 0.98.

Conclusions: This study demonstrated that the use of a binary classifier model developed from selected AUs can be an effective tool for evaluating cancer pain. The implementation of an APA classifier can be useful for detecting potential pain fluctuations. In the context of APA research, further investigations are necessary to refine the process and particularly to combine this data with multi-parameter analyses such as speech analysis, text analysis, and data obtained from physiological parameters.

Objectives: Offset analgesia (OA) is the phenomenon where the perceived pain intensity to heat stimulation disproportionally decreases after a slight decrease in stimulation temperature. The neural mechanisms of OA are not fully understood, but it appears that both peripheral and central temporal filtering properties are involved. Chemotherapy with oxaliplatin often causes acute peripheral sensory neuropathy, and manifests primarily as a cold induced allodynia. The aim of this exploratory patient study was to investigate if OA was affected by the neurotoxic effects of adjuvant oxaliplatin treatment.

Methods: OA was assessed in 17 colon cancer patients during 12 cycles of adjuvant oxaliplatin treatment. The OA response was estimated as the decrease in pain intensity caused by a temperature decrease from 46 °C to 45 °C. Changes in the OA during the treatment period was estimated using a mixed linear model and corrected for multiple comparisons by Sidak's test.

Results: OA was increased significantly when assessed before the 2nd, 3rd, 5th, 6th, 9th, and 10th treatment cycle compared to the first (baseline) treatment (p<0.05).

Conclusions: OA is generally decreased in persons suffering from chronic pain or peripheral neuropathy as compared to healthy controls. But in the present study, OA increased during chemotherapy with oxaliplatin. The underlying mechanism of this unexpected increase should be further explored.

Objectives: All pain research combined advances the different domains of the biopsychosocial model and its interactions. However, there may be discrepancies between individual countries in their biomedical, psychological or social focus to pain research. As a proxy for this possible discrepancy, we analysed the biopsychosocial orientation of presentations at a recent major international pain conference.

Methods: The primary aim was to investigate whether there are geographical differences across Europe regarding the biopsychosocial orientation of workshop presentations at the 12th EFIC congress. The secondary aim was to investigate whether there were differences between female and male presenters regarding the biopsychosocial focus of their presentations. All available workshop abstracts were blinded and categorised by two independent reviewers as biomedical, psychosocial, biopsychosocial, or not applicable. Psychosocial and biopsychosocial were merged to non-biomedical.

Results: Of the 140 available abstracts, 126 abstracts could be categorised (biomedical: 51 %; non-biomedical: 49 %). Three clusters of countries emerged: (1) countries with a clear majority (≥80 %) of non-biomedical presentations (The Netherlands and Belgium); (2) countries with a balance between biomedical and non-biomedical presentations (United Kingdom, Denmark, Norway, Sweden and Finland); and (3) countries with a clear majority (71-100 %) of biomedical presentations (Italy, Germany, Switzerland and France). Overall, women delivered more presentations than men (70 vs. 56 presentations), and delivered proportionally more non-biomedical presentations (57 %) whereas men delivered proportionally more biomedical presentations (61 %).

Conclusions: Analysis of the 12th EFIC congress revealed geographical and gender differences in biopsychosocial orientation. Whether this reflects established differences in pain research requires further investigation.

Objectives: Repetitive transcranial magnetic stimulation (rTMS) has been found to be effective in chronic neuropathic pain conditions. However, information about the combined effects of rTMS and antidepressant treatment is scarce. We studied the outcome of rTMS and concurrent antidepressant treatment in patients with neuropathic pain.

Methods: In this retrospective, real-world study, 34 patients with neuropathic pain, who were considered resistant or not benefitting from conventional treatment, received rTMS treatment between 2017 and 2020. Pain-related factors were measured using the Numerical Rating Scale (NRS), Global Impression of Change (GIC), and Beck Depression Inventory.

Results: A decrease in pain intensity and pain interference assessed with NRS was observed after 10 treatment sessions in 16 patients. The impression of change was positive in 20 patients. Half of the patients (n=17) used antidepressant medication, while half (n=17) did not. A concurrent use of antidepressants with therapeutic rTMS was significantly linked with less pain intensity relief when compared with the nonuse of antidepressants (p=0.019). The impression of change was significantly in favor of the antidepressant nonuser group (p=0.002). No group differences in pain interference were found between the groups.

Conclusions: Therapeutic rTMS for neuropathic pain is plausibly sensitive to interference with antidepressant medication. The exact mechanism of our findings remains to be elucidated; confirmatory studies are warranted.