Volume 21, Issue 3

Objectives Heart rate variability (HRV) is an important physiological measure of the capacity for neurogenic homeostatic regulation, and an indirect measure of emotional processing. We aimed to investigate whether HRV parameters are altered in people with chronic low back pain when compared to healthy controls. Methods We searched on PubMed, Scopus, CINAHL, Web of Science, Cochrane Library, and PsycINFO from inception to January 2018. The inclusion criteria were: patients with non-specific chronic low back pain, absence of radiculopathy, age from 18 to 65 years, and comparison with healthy controls. Data extraction was performed by two independent review authors. The methodological quality of the studies was assessed using the appraisal tool for cross-sectional studies. Results After screening 2,873 potential articles, two studies met the inclusion criteria. Studies were composed of 153 patients with chronic low back pain and 62 healthy controls. An electrocardiogram was used to record HRV and linear methods (time and frequency) were used to analyze the results. The main findings indicate that patients with chronic low back pain have a significant reduction in HRV, with sympathetic predominance compared to healthy controls. Conclusions There is limited evidence suggesting that chronic low back pain patients presented a lower vagal activity evidenced by HRV, when compared to healthy controls. The results of this systematic review should be interpreted with caution due to the restricted number of included studies, small sample sizes and different protocols used to measure HRV. The limited evidence about HRV alterations in low back pain also suggests the need of future studies to investigate if HRV parameters can be a useful measure in chronic pain samples or even if it can be used as an outcome in clinical trials aiming to investigate the effectiveness of interventions based on emotion regulation.

Objectives Our objective was to systematically review and meta-analyse relevant studies to determine the prevalence of musculoskeletal chest pain in the emergency department. Methods This review was constructed while confirming to the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. PubMed, Cochrane Library, SCOPUS, Science Direct, and OVID were systematically searched from their inception to January 19, 2020, to identify observational studies, where the prevalence of musculoskeletal causes of chest pain was reported in isolation or in combination with other causes or could be calculated from the available data. Results A meta-analysis of the nine included studies, having a total of 14,743 participants, showed the global pooled prevalence of musculoskeletal chest pain in the emergency department to be 16% (10–22%) [ I 2 =99.24%]. The pooled prevalence for the European continent was 17% (9–25%) [ I 2 =99.51%] and that for the urban areas was 13% (7–19%) [ I 2 =99.00%]. Conclusions This review provides a reliable estimate of the prevalence of musculoskeletal chest pain in the emergency department. More studies providing age and gender-specific data for the prevalence of musculoskeletal chest pain in the emergency department should be carried out. A paucity of such data from rural areas also needs to be addressed in future research work. The prevalence values from this study will be useful in the application of Bayesian reasoning utilised in diagnosing patients, where the process of Bayesian arguing begins by knowing pre-test probabilities of different differential diagnosis, in this case that of musculoskeletal chest pain in the emergency department.

Objectives Driving is one of the most widespread aspects of daily living to people in the United States and is an active process that requires various cognitive functions, such as attention. Chronic low back pain (CLBP) is one of the more prevalent and costly health conditions in the world, with individuals who report CLBP also reporting significant impairment across different domains of daily life both physically and cognitively. However, despite the prevalence of these two constructs, research detailing the experience of driving in pain remains largely underrepresented. This cross-sectional study sought to characterize the driving experience of people who experience CLBP, focusing on the psychological constructs related to chronic pain like pain catastrophizing, affective responses (irritability, anxiety, fear), and self-reported driving behaviors and outcomes. Methods This study distributed an online questionnaire measuring pain, disability, and other psychological constructs commonly associated with CLBP like pain catastrophizing through M-turk to 307 U.S. participants with recurring CLBP and regular driving activity. Participants also answered questions regarding driving in pain, affective responses to driving in pain (i.e., irritability, anxiety, and fear), driving behaviors and violations, driving avoidance habits as a result of pain, opioid use, using pain medication while driving, and recent vehicle collisions within the past three years. Bivariate correlations were used to compare study variables, and one-way ANOVA’s were used to compare means between participants with and without a collision history within the past three years. Results Findings demonstrated significant positive associations not only between the psychological factors commonly associated with chronic pain, such as pain intensity, pain disability, pain catastrophizing, and the cognitive intrusion by pain, but also statistically significant relationships between these measures and pain intensity while driving, affective responses to driving in pain, driving violations, and driving avoidance habits. Additionally, in comparison to participants with no collision history within the past three years, participants who had been driving during a vehicle collision reported greater pain catastrophizing and cognitive intrusion by pain scores. Conclusions To our knowledge, the current study is the first to characterize driving experience specifically among individuals with CLBP, with attention to the relationship among key sensory, affective, and cognitive psychological metrics as well as self-reported driving history and behavior. The current findings reinforce multiple associations between pain and cognitive-affective variables that have been observed in literature outside the driving context, including pain intensity, anger, inattention, and behavioral disruption. Given that driving is a pervasive, potentially risky behavior that requires some form of cognitive focus and control, the current findings point to a continued need to examine these associations within this specific life context. We believe we have laid a groundwork for research considering the role of psychological pain variables in a driving performance. However, the nature of our analyses prevents any sort of causality from being inferred, and that future experimental research is warranted to better understand and explain these mechanisms underlying driving in pain while accounting for participant bias and subject interpretation.

Objectives Office workers with chronic neck pain demonstrates signs of widespread hyperalgesia, less efficient descending pain modulation, which could indicate sensitization of central pain pathways. No studies have assessed a wide variety of office workers with different chronic neck pain disorders and assessed the impact of pain intensity on assessments of central pain pathways. This study aimed to assessed pressure pain thresholds (PPTs), temporal summation of pain (TSP) and conditioned pain modulation (CPM) and to associate these with pain intensity and disability in subgroups of office workers. Methods One hundred-and-seventy-one office workers were distributed into groups of asymptomatic and chronic neck pain subjects. Chronic neck pain was categorized as chronic trapezius myalgia and chronic non-specific neck pain and as ‘mild-pain’ (Visual Analog Scale [VAS]≤3) and ‘moderate-pain’ (VAS>3) groups. PPTs, TSP, CPM, and Copenhagen Psychosocial Questionnaire II were assessed in all subjects. Neck Disability Index and Pain Catastrophizing Scale were assessed in all the symptomatic office workers. Results PPTs were lower in moderate pain (n=49) and chronic trapezius myalgia (n=56) compared with asymptomatic subjects (n=62, p<0.05). TSP was facilitated in moderate pain group compared with mild pain (n=60, p<0.0001) group and asymptomatic subjects (p<0.0001). No differences were found in CPM comparing the different groups (p<0.05). Multiple regression analysis identified Neck Disability Index and TSP as independent factors for prediction of pain intensity in chronic trapezius myalgia (R 2 =0.319) and chronic non-specific neck pain (R 2 =0.208). Somatic stress, stress and sleep as independent factors in chronic non-specific neck pain (R 2 =0.525), and stress in moderate pain group (R 2 =0.494) for the prediction of disability. Conclusions Office workers with chronic trapezius myalgia and moderate pain intensity showed significant signs of widespread pressure hyperalgesia. Moreover, the moderate pain group demonstrated facilitated TSP indicating sensitization of central pain pathways. Neck Disability Index and TSP were independent predictors for pain intensity in pain groups. Sleep and stress were independent predictors for disability.

Objectives The relationship of pain sensitivity with pain and disability in low back pain (LBP) is complicated. It has been suggested increased understanding of dynamic quantitative sensory testing (QST) might be useful in increasing understanding of these relationships. This study aimed to create subgroups based on participant responses to dynamic QST, profile these subgroups based on multidimensional variables (including clinical measures of pain and disability, psychological and lifestyle variables and static QST), and investigate the association of subgroup membership with levels of pain intensity, LBP-related disability and disability risk at 12-month follow up. Methods Participants (n=273) with dominant axial chronic non-specific LBP with duration of pain >3 months were included in this study. At baseline, eligible participants completed a self-report questionnaire to collect demographic, clinical, psychological and lifestyle data prior to dynamic and static QST. Dynamic QST measures were conditioned pain modulation (CPM) and temporal summation (TS). At 12-months follow up, clinical data were collected, including pain intensity and LBP-related disability. Sub-groups were formed by cross-tabulation. Analysis was undertaken to profile dynamic QST subgroup on demographic, clinical, psychological, lifestyle and static QST measures. Associations between dynamic QST subgroups and follow-up clinical variables were examined. Results Based on dynamic QST, participants were allocated into four subgroups; normal CPM and normal TS (n=34, 12.5%); normal CPM and facilitated TS (n=6, 2.2%); impaired CPM and normal TS (n=186, 68.1%); impaired CPM and facilitated TS (n=47, 17.2%). At baseline no differences were demonstrated between subgroups across most clinical variables, or any psychological or lifestyle measures. The two subgroups with impaired CPM were more likely to have a higher number of painful body areas. Cold pain sensitivity was heightened in both the subgroups with facilitated TS. Subgroups did not differ across pain intensity, LBP-related disability and disability risk stratification at follow-up. Conclusions The profiles of people with axial LBP did not vary significantly across dynamic QST subgroups, save for those in groups with impaired CPM being more likely to have more widespread symptoms and those with facilitated TS having heightened cold pain sensitivity. Further, subgroup membership was not related to future pain and disability. The role of dynamic QST profiles in LBP remains unclear. Further work is required to understand the role of pain sensitivity in LBP. The utility of dynamic QST subgrouping might not be in determining of future disability. Future research might focus on treatment modifying effects of dynamic QST subgroups.

Objectives It has been hypothesised that attentional bias to environmental threats can contribute to persistent pain. It is unclear whether people with acute low back pain (LBP) have an attentional bias to environmental threats. We investigated if attentional bias of threat related words is different in people with acute LBP and pain-free controls. Methods People with acute LBP and pain-free people completed a free viewing eye tracking task. Participants were simultaneously presented with two words, a threat related word and a neutral control word. Threat related words were general threat, affective pain and sensory pain. We conducted linear mixed models to detect differences between acute LBP and pain-free participants on five eye tracking outcome measures (dwell time, first fixation, latency to first fixation, first run dwell time and number of fixations). We calculated absolute reliability, (standard error of measure), and relative reliability (intraclass correlation coefficients [ICC 2,1]) for each eye tracking outcome measures. Results We recruited 65 people with acute LBP and 65 pain-free controls. Participants with acute LBP had a higher proportion of fixations towards the affective pain words ( M =0.5009, 95% CI=0.4941, 0.5076) than the pain-free controls had ( M =0.4908, 95% CI=0.4836, 0.4979), mean between group difference = −0.0101, 95% CI [−0.0198, −0.0004], p=0.0422. There was no difference between acute LBP and pain-free controls for the remaining eye tracking outcome measures (all p>0.05). The only outcome measure that had an ICC of more than 0.7 was the latency to first fixation (affective pain words ICC=0.73, general threat words ICC=0.72). Conclusions When compared with pain-free controls, people with acute LBP looked more often at affective pain words relative to neutral control words. This may indicate a form of engagement bias for people with acute LBP. Attentional bias was not consistent across outcome measures or word groups. Further research is needed to investigate the potential role of attentional bias in the development of persistent pain.

Objectives Low back pain is the most prevalent musculoskeletal condition, and causes activity limitations which result in reduced work productivity and high medical expenditure. The management of this condition has been challenging to both clinicians and researchers. While the use of Muscle Energy Technique (MET) as a potentially effective treatment strategy seems promising, studies examining MET combined with exercise therapy are scarce and studies with strong methodology are lacking. Therefore, this study aims to determine the effects of a combination of Dynamic Stabilization Exercises (DSE) and MET on selected biopsychosocial outcomes compared to DSE alone or conventional physiotherapy in the management of chronic non-specific low back pain (NSLBP). Methods A total of 125 (80 male and 45 female) patients with chronic NSLBP were involved in this study, they were recruited from Rasheed Shekoni Teaching hospital and Federal Medical centre Birnin-Kudu, Jigawa State, Nigeria. A random number generator method was used to allocate patients to either DSE + MET (n=41), DSE alone (n=39) or conventional physiotherapy (n=45). Interventions were administered twice a week over 12 weeks. Outcome measures included pain intensity, lumbar (flexion and extension) range of motion, functional-disability, self-perceived health status, limitations in activities and participation restrictions. These were assessed at baseline, mid-intervention at six weeks, post-intervention at 12 weeks and long term follow-up at 24 weeks. Data was analyzed using repeated-measures ANOVA to determine significance difference within groups and between groups. Results All intervention groups showed within-groups changes of the study outcomes over time (p<0.001). However, between-group comparisons showed greater improvements in pain intensity (F=7.91, p<0.001), lumbar ROM (flexion F=1.51, p<0.001; extension F=3.25, p<0.001), activity limitations/participation restrictions (F=3.7, p<0.001) and health status (F=10.9, p<0.001) for the intervention in which MET and DSE were combined. The MET plus DSE interventions were superior to DSE and convention physiotherapy for all outcome measures, except for functional disability (F=0.53, p=0.590). Conclusions The data from this study showed MET combined with DSE had greater therapeutic benefits compared to DSE or conventional physiotherapy on selected biopsychosocial outcomes in patients with chronic NSLBP. The findings from the study show that the combination of MET with DSE is safe and has beneficial effects in the management of patients with chronic NSLBP. Clinical trial registration The study protocol has been registered with www.ClinicalTrial.gov with the registration number NCT3449810.

Objectives Persistent pain is common in HIV patients and breast cancer (BC) survivors. The aim of this study was to compare two patient groups with neuropathic pain (NP) regarding several psychological variables and Health-related Quality of Life. Although, treatment of pain is always planned individually, the knowledge of the differences and similarities between the patient groups may help us to understand more precisely the targets of the interventions for pain. Methods Eighty nine BC and 73 HIV patients with symptoms of neuropathic pain (patients with ≥3/7 in the Douleur Neuropathique four interview part (DN4i)) participated in a cross-sectional study. Patients completed questionnaires about mood (HADS), symptoms of insomnia (ISI), pain catastrophizing (PCS), personality (TIPI), Mental and Physical Health-related Quality of Life (M/PHrQoL, RAND/SF-36), and pain intensity and interference (BPI). Analyses were applied by using t-tests and linear regression to assess associations between the studied factors. Results HIV patients reported higher anxiety (p<0.001), depressive symptoms (p<0.001), pain catastrophizing (p<0.001) and pain interference (p<0.001), poorer sleep (p<0.001), and lower HrQoL in all dimensions compared with BC survivors. There were significant differences in personality traits extraversion, emotional stability, and agreeableness between the two patient groups. In HIV patients, pain interference ( β =−0.344, p<0.001) and mood ( β =−0.580, p<0.001) and in the BC group, mood ( β =−0.591, p<0.001), extraversion ( β =0.229, p=0.005) and sleep ( β =−0.154, p=0.042) associated with MHrQoL. Pain interference (HIV β =−0.645, p<0.001, BC β =−0.491, p<0.001) and age (HIV β =−0.016, p=0.042 and BC β =−0.018, p=0.019) associated with PHrQoL in both groups, and catastrophizing in the BC group ( β =−0.303, p<0.001). Conclusions HIV patients and BC survivors with neuropathic pain, measured with DN4i, have significant differences in various health-related variables and Health-related Quality of Life with both patient groups reporting low HrQoL. The differences in low HrQoL may reflect the fundamental differences between these diseases, BC survivors in remission and HIV patients living with a chronic disease that is under control. This study brings information about the diversity of different patient populations with symptoms of neuropathic pain, and how neuropathic pain associates with wide range of health-related factors. Interventions to support better coping with the symptoms of neuropathic pain could be tailored more individually if the background disease is taken into account.

Objectives To assess the long-term outcome of breast reconstructions with special focus on chronic postsurgical pain (CPSP) in a larger cohort of breast cancer survivors. Methods A cross-sectional study on 121 women with mastectomy and breast reconstruction after mean 2 years 4 months follow up. The mean time from breast reconstruction to the follow-up visit was 4 years 2 months. We studied surveys on pain (Brief Pain Inventory, BPI and Douleur Neuropathique 4, DN4), quality of life (RAND-36 health survey), sleep (insomnia severity questionnaire, ISI), mood (Beck’s Depression Index, BDI; Hospital Anxiety and Depression Scale, HADS), and a detailed clinical sensory status. Patients were divided into three groups: abdominal flap (Deep inferior epigastric perforator flap, DIEP; Free transverse rectus abdominis flap, fTRAM, and Pedicled transverse rectus abdominis flap, pTRAM), dorsal flap (Latissimus dorsi flap, LD and Thoracodorsal artery perforator flap, TDAP), and other (Transverse myocutaneous gracilis flap, TMG; implant). Clinically meaningful pain was defined ≥ 4/10 on a numeric rating scale (NRS). We used patients’ pain drawings to localize the pain. We assessed preoperative pain NRS from previous data. Results 106 (87.6%) of the patients did not have clinically meaningful persistent pain. We found no statistically significant difference between different reconstruction types with regards to persistent pain ( p =0.40), mood (BDI-II, p =0.41 and HADS A, p =0.54) or sleep ( p =0.14), respectively. Preoperative pain prior to breast reconstruction surgery correlated strongly with moderate or severe CPSP. Conclusions Moderate to severe CPSP intensity was present in 14% of patients. We found no significant difference in the prevalence of pain across different reconstruction types. Preoperative pain associated significantly with postoperative persistent pain.

Objectives Emotions are involved in the identification of safety cues in the environment, and are also related to social interaction through recognition of emotional facial expressions. Heart rate variability (HRV) can be an indicator of the adaptive response of the autonomic nervous system to stressful conditions, including pain. This study aimed to investigate the emotional processing in a sample of patients with chronic musculoskeletal by measuring the resting-state HRV and the ability to recognize facial emotion expressions. Methods This cross-sectional study was composed of 40 participants with chronic musculoskeletal pain and 40 asymptomatic participants. Resting HRV was measured for 10 min. The facial emotion recognition task was presented in videos and included modification from a neutral expression to faces of fear, anger, sadness, happiness, and disgust. For the facial emotion recognition task, the hit rate (%) and response time for each emotional category were measured. Results The symptomatic group had a mean high frequency (HF) lower (mean = 34.14; SD = 16.95; p<0.001) than the asymptomatic group (mean = 51.11; SD = 13.01; p<0.001). The emotional facial expressions of disgust ( H (1, 80)=7.82; p<0.01), anger ( H (1, 80)=13.56; p<0.01), sadness ( H (1, 80)=6.58; p=0.01), and happiness ( H (1, 80)=12.68; p<0.01) were those for which volunteers from the symptomatic group had a lower hit rate of correct answers compared to the asymptomatic group. The response time to corrected answers showed a major group effect ( F (1.77)=21.11; p<0.001) and emotional category ( F (4.308)=174.21; p<0.001), without presenting any interaction between the factors ( F (4.308)=0.446; p=0.775). The symptomatic group was slower to perform the task of identifying facial emotional expression (7.066 s; SD = 1.188) than the participants in the asymptomatic group (6.298 s; SD = 1.203) for all emotional categories. Conclusions Participants with chronic musculoskeletal pain presented a lower vagal activity evidenced by HRV. Participants in the symptomatic group showed lower ability to recognize faces of disgust, anger, and sadness when compared to asymptomatic participants. Considering that individuals with low resting HF-HRV have difficulties with regulating their emotions, the lower vagal activity and lower ability to recognize faces of emotional expressions observed in chronic musculoskeletal pain may suggest alterations in emotional processing. This study may shed light on changes in the emotional processing and in the autonomic nervous system in this population.

Objectives Sleep disturbances are highly prevalent in patients with chronic pain. However, the majority of studies to date examining sleep disturbances in patients with chronic pain have been population-based cross-sectional studies. The aims of this study were to 1) examine the frequency of sleep disturbances in patients referred to two interdisciplinary chronic pain clinics in Denmark, 2) explore associations between sleep disturbances and pain intensity, disability and quality of life at baseline and follow-up, and 3) explore whether changes in sleep quality mediated the relationships between pain outcomes at baseline and pain outcomes at follow-up. Methods We carried out a longitudinal observational study, examining patients enrolled in two chronic pain clinics assessed at baseline (n=2,531) and post-treatment follow-up (n=657). Patients reported on their sleep disturbances using the sleep quality subscale of the Karolinska Sleep Questionnaire (KSQ), their pain intensity using 0–10 numerical rating scales, their pain-related disability using the Pain Disability Index (PDI), and quality of life using the EuroQol-VAS scale. The average time between baseline and follow-up was 207 days (SD=154). Results At baseline, the majority of patients reported frequent sleep disturbances. We found a significant association at baseline between self-reported sleep disturbances and pain intensity, pain-related disability, and quality of life, where greater sleep disturbance was associated with poorer outcomes. At follow-up, patients reported significant improvements across all pain and sleep outcomes. In two mediation models, we showed that changes in sleep disturbances from baseline to follow-up were significantly associated with (i) pain intensity at follow-up, and (ii) pain disability at follow-up. However, baseline pain intensity and disability scores were not associated with changes in sleep disturbances and, we did not find evidence for significant mediation of either pain outcome by changes in sleep disturbances. Conclusions Self-reported sleep disturbances were associated with pain outcomes at baseline and follow-up, with greater sleep disturbances associated with poorer pain outcomes. Changes in sleep quality did not mediate the relationships between baseline and follow-up scores for pain intensity and disability. These findings contribute to a growing body of evidence confirming an association between sleep and chronic pain experience, particularly suggestive of a sleep to pain link. Our data following patients after interdisciplinary treatment suggests that improved sleep is a marker for a better outcome after treatment.

Objectives Complex regional pain syndrome (CRPS) is a disabling usually post-traumatic pain condition. International guidelines emphasize early diagnosis for treatment and improved outcome. Early intense and persistent pain along with features of autonomic dysfunction in the first week’s post-injury are early warning signs for development of CRPS. We have previously reported a delayed diagnosis of CRPS. The main purpose of the present study was to investigate possible causes of a delayed diagnosis, with a special focus of recognition of risk factors. Methods A total of 52 CRPS 1 (without detectable nerve damage) and CRPS 2 (with evidence of nerve lesion) patients were included in the study. When examined at OUS-Rikshospitalet, we retrospectively asked the patients on the development of pain and autonomic abnormalities from the time of the eliciting injury, performed a thorough clinical investigation with an emphasis on signs of autonomic failure and compared symptoms and clinical findings with such information in previous medical records. We also evaluated symptoms and signs according to the type of injury they had suffered. Results Of a total of 52 patients (30 women and 22 men, mean age 39.0 years at the time of injury), 34 patients had CRPS type 1 (65.4%) and 18 CRPS type 2 (34.6%), 25 patients with pain in the upper and 27 in the lower extremity. A total of 35 patients (67.3%) were diagnosed with CRPS (following mean 2.1 years) prior to the investigation at OUS-Rikshospitalet (mean 4.86 years following injury). Mean time from injury to diagnosis was 33.5 months (SD 30.6) (2.8 years) for all patients. In retrospect, all 17 patients first diagnosed at OUS met the CRPS diagnosis at an earlier stage. All patients retrospectively reported intense pain (numeric rating scale > 7) from the time of injury with a large discrepancy to previous medical records which only stated intense pain in 29.4% of patients with CRPS type 1 and 44.4% of patients with CRPS type 2 within the first four months. While the patients reported an early onset of autonomic dysfunction, present in 67.3 and 94.2% of the patients within one week and one month, respectively, reports of autonomic abnormalities within the first four months was far less (maximum in 51.7% of patients with CRPS type 1 and in 60% in CRPS 2). In 10 patients with CRPS type 1, no symptom nor sign of autonomic abnormalities was reported. Conclusions We still find a significant delay in the diagnosis of CRPS. There is a large discrepancy between both self-reporting of intense, disproportionate pain, as well as symptoms of autonomic abnormalities from the time of injury, and documentation in previous medical records. Our findings suggest a lack of awareness of risk factors for the development of CRPS, such as early intense pain and autonomic abnormalities without recovery, contributing to delayed diagnosis. The present results suggest causes of delayed CRPS-diagnosis. An increased attention to early warning signs/risk factors may improve diagnosis of CRPS.

Background and aims There is very little published evaluation of the treatment of military veterans with chronic pain, with or without post-traumatic stress disorder. Few clinical services offer integrated treatment for veterans with chronic pain and PTSD. Such veterans experience difficulty in accessing treatment for either condition: services may consider each condition as a contraindication to treatment of the other. Veterans are therefore often passed from one specialist service to another without adequate treatment. The veteran pain management programme (PMP) in the UK was established to meet the needs of veterans suffering from chronic pain with or without PTSD; this is the first evaluation. Methods The PMP was advertised online via veteran charities. Veterans self-referred with accompanying information from General Practitioners. Veterans were then invited for an inter-disciplinary assessment and if appropriate invited onto the next PMP. Exclusion criteria included; current severe PTSD, severe depression with active suicidal ideation, moderate to severe personality disorder, or who were unable to self-care in the accommodation available. Treatment was by a team of experienced pain management clinicians: clinical psychologist, physiotherapist, nurse, medical consultant and psychiatrist. The PMP was delivered over 10 days: five residential days then five single days over the subsequent 6 months. The PMP combines cognitive behavioural treatment, which has the strongest evidence base, with more recent developments from mindfulness-based CBT for pain and compassion-focused therapy. Standard pain management strategies were adapted to meet the specific needs of the population, recognising the tendency to use demanding activity to manage post-traumatic stress symptoms. Domains of outcome were pain, mood, function, confidence and changes in medication use. Results One hundred and sixty four military veterans started treatment in 19 programmes, and 158 completed. Results from those with high and low PTSD were compared; overall improvements in all domains were statistically significant: mood, self-efficacy and confidence, and those with PTSD showed a reduction (4.3/24 points on the IES-6). At the end of the programme the data showed that 17% reduced opioid medication and 25% stopped all opioid use. Conclusions Veterans made clinically and statistically significant improvements, including those with co-existing PTSD, who also reduced their symptom level. This serves to demonstrate the feasibility of treating veterans with both chronic pain and PTSD using a PMP model of care. Implications Military veterans experiencing both chronic pain and PTSD can be treated in a PMP adapted for their specific needs by an experienced clinical team.

Objectives Opioids are commonly prescribed post-surgery. We investigated the proportion of patients who were prescribed any opioids 6–12 months after two common surgeries – laparoscopic cholecystectomy and gastric by-pass (GBP) surgery. A secondary aim was to examine risk factors prior to surgery associated with the prescription of any opioids after surgery. Methods We performed a retrospective observational study on data from medical records from patients who underwent cholecystectomy (n=297) or GBP (n=93) in 2018 in the Region of Västerbotten, Sweden. Data on prescriptions for opioids and other drugs were collected from the patients` medical records. Results There were 109 patients (28%) who were prescribed opioids after discharge from surgery but only 20 patients (5%) who still received opioid prescriptions 6–12 months after surgery. All 20 of these patients had also been prescribed opioids within three months before surgery, most commonly for back and joint pain. Only 1 out of 56 patients who were prescribed opioids preoperatively due to gallbladder pain still received prescriptions for opioids 6–12 months after surgery. Although opioid use in the early postoperative period was more common among patients who underwent cholecystectomy, the patients who underwent GBP were more prone to be “long-term” users of opioids. In the patients who were prescribed opioids within three months prior to surgery, 8 out of 13 patients who underwent GBP and 12 of the 96 patients who underwent cholecystectomy were still prescribed opioids 6–12 months after surgery (OR 11.2; 95% CI 3.1–39.9, p=0,0002). Affective disorders were common among “long-term” users of opioids and prior benzodiazepine and amitriptyline use were significantly associated with “long-term” opioid use. Conclusions The proportion of patients that used opioids 6–12 months after cholecystectomy or GBP was low. Patients with preoperative opioid-use experienced a significantly higher risk of “long-term” opioid use when undergoing GBP compared to cholecystectomy. The indication for being prescribed opioids in the “long-term” were mostly unrelated to surgery. No patient who was naïve to opioids prior surgery was prescribed opioids 6–12 months after surgery. Although opioids are commonly prescribed in the preoperative and in the early postoperative period to patients with gallbladder disease, there is a low risk that these prescriptions will lead to long-term opioid use. The reasons for being prescribed opioids in the long-term are often due to causes not related to surgery.

Objectives Increased symptoms related to central sensitization have previously been reported in inflammatory bowel disease (IBD) patients, identified by the original central sensitization inventory (CSI-25). However, the recently developed CSI short form (CSI-9) may be more clinically useful. The aim of the present study was to evaluate the performance of CSI-9 compared to the original CSI-25 in individuals with IBD. Study objectives were to investigate the criterion validity of the CSI-9 to the CSI-25, assess individual association of the CSI measures with clinical features of IBD and pain presentations, and to establish disease-specific CSI-9 and CSI-25 cut-off scores for discriminating the presence of self-reported pain in individuals with IBD. Methods Cross-sectional online survey was performed on adults with IBD exploring self-reported demographics, comorbidity, and clinical IBD and pain features. Criterion validity of the CSI-9 was investigated using intraclass correlation coefficient (ICC) 3,1 . Area under the receiver operating characteristic curve (AUC-ROC) analysis was conducted to investigate the discriminative ability of both versions of CSI. Results Of the 320 participants, 260 reported the presence of abdominal and/or musculoskeletal pain. CSI-9 and CSI-25 demonstrated substantial agreement (ICC 3,1 =0.64, 95% CI [0.58, 0.69]). AUC (95% CI) indicated that CSI-9 (0.788 (0.725, 0.851), p<0.001) and CSI-25 (0.808 (0.750, 0.867), p<0.001) were able to adequately discriminate the presence of pain using cut-offs scores of ≥17 (CSI-9) and ≥40 (CSI-25). Abdominal pain severity was the only feature to differ in significant association to CSI-25 (p=0.002) compared to CSI-9 (p=0.236). All other features demonstrated significant associations to both CSI versions, except age (p=0.291 and 0.643) and IBD subtype (p=0.115 and 0.675). Conclusions This is the first study to explore and validate the use of CSI-9 in IBD patients. Results demonstrated concurrent validity of the CSI-9 to CSI-25, with similar significant association to multiple patient features, and a suggested cut-off value of 17 on CSI-9 to screen for individuals with pain experiences. Study findings suggest that CSI-9 is suitable to use as a brief tool in IBD patients.

Objectives Chronic pain patients often report higher levels of negative emotions, suggesting reduced ability to regulate emotions effectively, however, little is known of the underlying neural cognitive mechanisms. Therefore, the aim of this study was to explore brain activity and connectivity during cognitive reappraisal in chronic low back pain (CLBP). Methods This study recruited 24 female participants; 12 with CLBP and 12 healthy controls. Participants completed an emotion regulation task that involved cognitive reappraisal of negative images during functional magnetic resonance imaging. The negative affect following each image and perceived success of the task were reported. Region of interest and seed-to-voxel analyses were conducted using key regions involved in cognitive reappraisal (i.e., amygdalae and dorsomedial prefrontal cortex) as seed regions. Results During the task, there were no group differences in the behavioural measures and blood oxygen level-dependent (BOLD) brain activation in the seed regions. Functional connectivity analysis showed reduced coupling between the amygdalae and dorsolateral prefrontal cortex, orbitofrontal cortex and inferior parietal cortex in the CLBP group compared to controls. Connectivity between the amygdala and inferior parietal cortex positively correlated with the percent of reduced negative affect during reappraisal in the CLBP group. Conclusions These preliminary findings demonstrate that individuals with CLBP exhibit similar emotion regulation abilities to healthy controls at the behavioural and BOLD level. However, altered functional connectivity observed in the CLBP group may reduce effective cognitive reappraisal. These results provide evidence for the potential clinical impact of network changes in CLBP.

Objectives Social deprivation is associated with a higher prevalence of chronic pain in children and an under-representation in specialist paediatric chronic pain programs. Our primary objective was to determine if there was a relationship between social deprivation and paediatric chronic pain referrals in Ireland. Secondary objectives included analysing for differences between deprivation groups in pain characteristics and function that are recorded at first clinic visit. Methods Families attending the national paediatric complex pain service in Dublin, Ireland, complete questionnaires on pain characteristics, parental pain catastrophizing, and pain-related disability including sleep quality and school attendance. We retrospectively reviewed records from between February 2016 and November 2019 on 288 patients. Social deprivation was assessed using the Pobal HP Deprivation Index, which is based on data from the Irish national census. Results Referrals followed a normal distribution across deprivation grades. Children in the disadvantaged group had a longer duration of pain, greater use of screens at bedtime, and longer sleep onset latency. Parents in the disadvantaged group had significantly higher levels of parental pain catastrophizing. Conclusions In Ireland, while paediatric chronic pain referrals were normally distributed across deprivation group, the disadvantaged group was different in several ways that may be clinically significant. Further work will be needed to determine the longitudinal relationship between these factors before and after the referral and initial review. Screening for, and targeting, potential risk factors for pain chronicity may be needed to harmonize treatment outcomes in children from socially disadvantaged families.

Objectives The literature on conditioned pain modulation (CPM) is inconclusive in relation to low-back pain and it is unclear how CPM affects temporal summation as a proxy of central pain integration. The aim of this study was to examine whether the CPM effect would be different on pain induced by temporal summation than single stimuli in a group of low back pain patients. Methods A total of 149 low-back pain patients were included. CPM was examined using single, repeated and temporal summation (repeated-single difference) of mechanical pressure pain as test stimuli at an individualized, fixed supra-pain-threshold force, before and after 2 min of cold pressor test (0–2 degrees Celsius). Participants were categorized as CPM responders or non-responders according to three different criteria: simple (any pain inhibition), strict (pain inhibition of more than 10VAS) and reversed (pain inhibition or facilitation of less than 10VAS). Clinical data on back pain was collected for correlation and descriptive purposes. Results Significant modulation was observed for all three test stimuli. Effects sizes were comparable in relative terms, but repeated pressure pain modulation was greater in absolute terms. No correlations to clinical data were observed, for any measure. Conclusions The current data suggests that repeated pressure pain may be better suited as the CPM test stimuli, than single pressure pain and temporal summation of pressure pain, as the CPM effect in absolute terms was greater. Employing temporal summation as the test stimulus in a CPM paradigm may be more sensitive than a single test stimulus.

Objectives The expression of pain in males and females involves complex socio-psychological mechanisms. Males may report lower pain to a female experimenter to appear strong, whereas females may report higher pain to a male experimenter to appear weak and to seek protection. However, evidence to support these stereotypes is inconclusive. Individuals who catastrophise about pain rate higher pain than those who do not. How pain catastrophising interacts with the effect of the experimenter’s sex on pain reports is yet to be explored. Thus, the aim of this study was to determine whether pain catastrophising moderated the effect of the experimenter’s sex on pain reports in healthy males and females. Methods Participants (n=60, 30 males) were assigned to one of four experimental conditions: males tested by male experimenters, males tested by female experimenters, females tested by male experimenters, and females tested by female experimenters. Participants completed the Pain Catastrophising Scale, and then sensitivity to heat and to blunt (pressure-pain threshold) and sharp stimuli was assessed on both forearms, and to high frequency electrical stimulation (HFS) administered to one forearm. Results Females reported lower pressure-pain thresholds than males irrespective of the experimenters’ sex. Females reported lower sharpness ratings to male than female experimenters only when the test stimuli were moderately or intensely sharp. Higher pain catastrophising scores were associated with higher sharpness ratings in females but not males. Additionally, higher pain catastrophising scores were associated with greater temporal summation of pain to HFS, and with lower pressure-pain thresholds in females who were tested by male experimenters. Conclusions These findings indicate that the experimenters’ sex and the participant’s pain catastrophising score influence pain reports, particularly in females. Awareness of these psychosocial factors is important in order to interpret pain responses in a meaningful way, especially when females are tested by male experimenters. A greater awareness of sex/gender role biases and their potential interaction with pain catastrophising may help researchers and clinicians to interpret pain reports in meaningful ways. In turn, this may help to improve delivery of treatments for patients with chronic pain.

Objectives It is our experience that a small portion of patients with neuropathic abdominal wall pain syndromes such as the anterior cutaneous nerve entrapment syndrome (ACNES) have a long term beneficial response following just one single tender point injection (TPI) with a local anesthetic agent. This report focuses on the phenomenon of ongoing pain relief following a single local anesthetic injection in neuropathic abdominal wall and groin pain syndromes. Methods This report is an overview based on earlier studies from a center of expertise for neuropathic abdominal wall and groin pain syndromes. All studies on neuropathic abdominal wall and groin pain syndromes reporting on efficacy of a diagnostic TPI using a local anesthetic agent were included. Results A total of 10 studies including 834 patients fulfilled study criteria. Each of these 10 studies found that approximately 10% (range, 4–25%) of the cases experienced persistent pain relief after a single TPI with lidocaine 1%. Conclusions Persistent pain relief after a single TPI using a local anesthetic agent may be observed in approximately one of 10 patients suffering from neuropathic abdominal wall or groin pain syndromes. When a patient is suspected of having a neuropathic abdominal wall or groin pain syndrome, a single TPI using a local anesthetic agent should be administered as long term pain relief may occasionally occur.