Volume 15, Issue 1

In this issue of the Scandinavian Journal of Pain , Pico-Espinosa and co-workers [1] report on the role of diabetes mellitus (DM) and hyperlipidaemia (HL) as risk factors for frequent pain in the back, neck and/or shoulders/arms (BNSP). Their study was based on a large population-based cohort with a four-year follow-up. They concluded that DM and HL may play a role in the aetiology of frequent BNSP, but this role may be different in men and women.

Background and aims Frequent back, neck and/or shoulder pain (BNSP) are common conditions which pose high burden for the society. Results from previous studies suggest that diabetes and hyperlipidaemia may be associated with a higher risk of getting such conditions, but there is in general, few studies based on longitudinal designs. The aim of this study was therefore to compare the risk of developing frequent BNSP in men and women with and without diabetes and/or hyperlipidaemia. Methods A longitudinal study based on the Stockholm Public Health Cohort was conducted based on subjects aged 45–84, who were free from pain at the mentioned sites in 2006 and followed up until 2010. The data in the current study is based on questionnaires, except socioeconomic status which was derived from Statistics Sweden. The exposure diabetes and hyperlipidaemia was self-reported and, a categorical variable was created; without any of the conditions, with hyperlipidaemia only, with diabetes only and with both conditions. The outcome frequent BNSP was defined using the following questions in the questionnaire in 2010: “ During the past 6 months, have you had pain in the neck or upper part of the back?”, “During the past 6 months, have you had pain in the lower back ?”, and “ During the past 6 months, have you had pain in the shoulders/arms ?”. All questions had three possible response options: no; yes, a couple of days per month or less often and; yes, a couple of days per week or more often. Those who reported weekly pain to at least one of these questions were considered to having frequent BNSP. Binomial regressions were run to calculate the crude and adjusted risk ratio (RR) in men and women separately. Additional analysis was performed in order to control for potential bias derived from individuals lost to follow-up. Results A total of 10,044 subjects fulfilled the criteria to be included in the study. The mean age of the sample was 60 years and evenly distributed by sex. After adjusting for age, body mass index, physical activity, high blood pressure and socioeconomic status, the RR for frequent BNSP among men with diabetes was 1.64 (95% CI: 1.23–2.18) and 1.19 (95% CI: 0.98–1.44) for hyperlipidaemia compared to men with neither diabetes nor hyperlipidaemia. Among women the corresponding RRs were 0.92 (95% CI: 0.60–1.14) and 1.23 (95% CI: 1.03–1.46). Having both diabetes and hyperlipidaemia at baseline was not associated with increased risk of frequent BNSP. Diabetes and hyperlipidaemia seems to be associated with an increased risk for frequent BNSP and the risk may differ between men and women. Behaviours and/or biological underlying mechanisms may explain the results. Conclusions This study suggests that metabolic diseases such as diabetes and hyperlipidaemia may have an impact on the pathophysiology of frequent BNSP and thus, contributes to the knowledge in musculoskeletal health. Furthermore, it confirms that men and women may differ in terms of risk factors for BNSP. Implications Health professionals should contemplate the results from this study when planning primary prevention strategies.

Background and aims Reduced pain sensitivity following exercise is termed exercise induced hypoalgesia (EIH). Preliminary evidence suggests that impairment of EIH is evident in individuals with whiplash associated disorders (WAD) following submaximal aerobic exercise. This study aimed to compare EIH responses to isometric and aerobic exercise in patients with chronic WAD and healthy controls and investigate relationships between EIH, conditioned pain modulation (CPM) and psychological factors in patients with chronic WAD. Methods A cross sectional pre-post study investigated the effect of a single session of submaximal aerobic cycling exercise and a single session of isometric timed wall squat exercise on EIH in a group of participants with chronic WAD ( n = 21) and a group of asymptomatic control participants ( n = 19). Bivariate analyses between EIH and baseline measures of CPM and psychological features (fear of movement, pain catastrophization and posttraumatic stress symptoms) were also investigated. Results The isometric wall squat exercise but not the aerobic cycling exercise resulted in EIH in both groups ( P < .023) with no between-group differences ( P > .55) demonstrated for either exercise. There were no significant associations measured between EIH (for either exercise performed), and CPM, or any of the psychological variables. Conclusions This study showed that individuals with chronic WAD and mild to moderate pain and disability, and no evidence of dysfunctional CPM, demonstrated reduced pain sensitivity, both in the cervical spine and over the tibialis anterior following an isometric, timed wall squat exercise. Cycling exercise did not increase pain sensitivity. Implications Individuals with chronic WAD and mild to moderate levels of neck pain and disability may experience less pain sensitivity both locally and remotely following an exercise program directed at nonpainful muscles performing isometric exercises. Individuals cycling for 30 min at 75% of age-predicted heart rate maximum do not experience increased pain sensitivity.

Background and aims Pain management is often inadequate in emergency departments (ED) despite the availability of effective analgesics. Interventions to change professional behavior may therefore help to improve the management of pain within the ED. We hypothesized that a 2-h educational intervention combining e-learning and simulation would result in improved pain treatment of ED patients with pain. Methods Data were collected at the ED of Horsens Regional Hospital during a 3-week study period in March 2015. Pain intensity (NRS, 0–10) and analgesic administration were recorded 24 h a day for all patients who were admitted to the ED during the first and third study weeks. Fifty-three ED nurses and 14 ED residents participated in the educational intervention, which took place in the second study week. Results In total, 247 of 796 patients had pain >3 on the NRS at the admission to the ED and were included in the data analysis. The theoretical knowledge of pain management among nurses and residents increased as assessed by a multiple choice test performed before and after the educational intervention ( P = 0.001), but no change in clinical practice could be observed: The administration for analgesics [OR: 1.79 (0.97–3.33)] and for opioids [2.02 (0.79–5.18)] were similar before and after the educational intervention, as was the rate of clinically meaningful pain reduction (NRS >2) during the ED stay [OR: 0.81 (CI 0.45–1.44)]. Conclusions Conduction of a 2-h educational intervention combining interactive case-based e-learning with simulation-based training in an ED setting was feasible with a high participation rate of nurses and residents. Their knowledge of pain management increased after completion of the program, but transfer of the new knowledge into clinical practice could not be found. Future research should explore the effects of repeated education of healthcare providers on pain management. Implications It is essential for nurses and residents in emergency departments to have the basic theoretical and practical skills to treat acute pain properly. A modern approach including e-learning and simulation lead to increased knowledge of acute pain management. Further studies are needed to show how this increased knowledge is transferred into clinical practice.

Background and aims Patients suffering from Complex Regional Pain Syndrome (CRPS) of the upper limb show a changed cortical representation of the affected hand. The lip area invades the former hand area contralateral to the affected hand. This change in cortical representation is correlated to the intensity of ongoing pain in patients with CRPS. Further studies revealed that restoration of the original representation coincides with a decrease of pain. Sensory-motor training protocols can increase and/or relocate cortical somatosensory and motor representation areas of the fingers, as shown, for example, in Braille reading individuals and professional violin players. Further, there is evidence that sensory-motor discrimination training has a beneficial effect on both the intensity of pain and the mislocalization of sensory-motor cortical areas in CRPS patients. Based on these propositions, we developed a novel sensory-motor self-training paradigm for CRPS patients to use in a home-based manner. Methods Ten CRPS patients performed the sensory-motor training for 2 weeks. The training consists of a braille-like haptic task with different training modes (bi-manual, speed and memory training). During the training, as well as 1 week before and after, patients were asked to fill out pain diaries. Furthermore, measures of impairment were acquired at baseline and post training. Results Patients showed significant pain reduction after the 2 week training period. The overall disability as well as the depression scores showed a trend to improve after the 2 week training. The reduction in pain was correlated with the total amount of training performed. Conclusions This is a first proof of principle study of a novel sensory-motor self-training protocol to reduce pain in CRPS patients. The more consistent the patients trained the larger the pain reduction. Sensory-motor training, which can be performed on a regular basis at home might provide a novel interventional strategy to improve symptoms of CRPS. Implications Although a larger study needs to be conducted to confirm our findings, including long-term follow-up, the results show, that a sensory-motor home-based training is a strategy worth exploring further for the reduction of pain as well as high frequency training for patients with CRPS.

Background and aim Studies have shown that pain is common among hospitalized patients and that there is a lack of compliance with pain management guidelines. Improving pain management does not only involve developing new drugs or technology; even more important is an effective organisation that utilises existing expertise. The aim of this study was to investigate whether pain in hospitalized patients can be reduced by implementing evidence-based pain management guidelines, providing education for staff and an organisation that includes pain responsibility nurses. Methods A cross-sectional study was carried out between 2009 and 2010 at two hospitals in southwest Sweden, comprising a baseline survey followed by an intervention. The study involved 306 patients, who answered questions about pain intensity at rest and while moving, disturbed sleep due to pain and whether they had used a pain rating scale while in hospital. Medical records were scrutinised for analgesic prescriptions. An intervention then took place, involving implementation of evidence-based guidelines, staff education and the introduction of pain responsibility nurses. A follow-up survey was carried out in 2012, in which 293 patients answered the same questions and their medical records were also reviewed. The baseline results were then compared with those of the follow-up survey. Results When compared with the baseline survey, the follow-up survey revealed significant differences in the use of validated pain rating instruments as well as the prescription of more appropriate analgesics. Prescription of paracetamol increased significantly in the follow-up survey; 56% of the patients were prescribed paracetamol on a regular basis, compared with 42% at baseline. There was also a significant increase in the use of strong opioids, from 38% at baseline to 55% at follow-up. Prescriptions of weak opioids decreased from 16% at baseline to 4% at follow-up. No significant differences were observed in patient pain levels in the follow-up survey. At baseline, 29% of the patients reported moderate to severe pain at rest (NRS 4–10) and at follow-up that figure was 24% (NRS 4–10). In both surveys, 41% reported moderate to severe pain (NRS 5–10) during movement. Thirty-nine percent reported disturbed sleep at night at both baseline and follow-up. Conclusions This study demonstrates that evidence-based guidelines made accessible to all staff as a pocket size booklet and on the intranet, in combination with staff education, pain responsibility nurses who informed other staff on their own wards, improved the prescription of analgesics in the hospitals studied. In order to achieve a noticeable effect for patients, i.e., reduced pain levels, an intervention containing more components than those employed in the present study is required. Implications Nurses and physicians need greater knowledge about the importance of pain rating. A vital part of pain management at hospitals is continuous evaluation of treatment outcomes to prevent severe pain and disturbed sleep. The complexity of pain and pain management requires commitment, time and knowledge on the part of healthcare staff. Multi-professional pain teams that support ward staff in pain management are necessary in order to reduce suffering and unnecessary pain in hospitalized patients.

Background and aims Musculoskeletal pain is a common symptom and many people even with chronic pain continue to work. The aim of our study is to analyze how musculoskeletal pain affects work wellbeing by comparing work engagement in employees with or without pain, and how pain-related risk of disability is associated with work engagement. In a separate analysis, we also studied, how psychosocial factors are related to work engagement. Methods This is a cross-sectional study of Finnish female employees of the city of Pori, Finland (PORi To Aid Against Threats (PORTAAT) study). Data was collected by trained study nurses and self-administrated questionnaires. Work well-being was measured by work engagement using Utrecht Work Engagement Scale (UWES-9) questionnaire and the burden of pain was measured by using the short version of Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ). Study population was divided into four groups: those without pain and the groups with low (I), medium (II) or high (III) ÖMPSQ score, reflecting increasing risk of long term disability due to musculoskeletal pain. The study nurse assessed psychosocial risk factors using defined core questions. Results We evaluated 702 female employees, 601 (86%) had suffered from musculoskeletal pain over the past 12 months, whereas 101 (14%) reported no pain at all. Pain was chronic (duration at least 3 months) in 465/601 (77%) subjects. Subjects with musculoskeletal pain were older, had higher BMI and were on sick leave more often than subjects without pain. Of the psychosocial risk factors, depression, type D personality, anxiety and hostility were significantly more common among subjects with musculoskeletal pain. Hypertension and the use of non-steroidal anti-inflammatory drugs were significantly more frequent in the musculoskeletal pain group. Quality of sleep and working capability were significantly better among persons without pain. Average weekly working hours were slightly higher among those with musculoskeletal pain. In crude analysis, work engagement (UWES-9) was similar in women without pain and those with musculoskeletal pain (4.96 vs . 4.79; p = 0.091). After adjustment for age, education years, BMI, working hours and financial satisfaction, the difference between the groups became statistically significant ( p = 0.036). Still, there was no difference between the groups of no-pain and low burden of pain ( p = 0.21, after adjustment). Work engagement was significantly lower in the groups of medium ( p = 0.024, after adjusted) and high ( p < 0.001, after adjustment) burden of pain. Linearity across the Linton tertiles was significant ( p < 0.001). In univariate and multivariate ordered logistic regression analyses relating study variables to the work engagement musculoskeletal pain per se did not enter in the model to explain work engagement. Work and family stress, type D personality and duration of sick leave due to pain reduced work engagement, whereas financial satisfaction, moderate and high leisure time physical activity and higher BMI improved it. Conclusions Among women with musculoskeletal pain psychosocial and lifestyle factors significantly correlate with work engagement, while the pain itself does not. Implications Special attention should be paid to the psychosocial aspects in female employees with musculoskeletal pain to improve work well-being and maintain work ability.

Background Pain after surgery is not uncommon with 30% of patients reporting moderate to severe postoperative pain. Early identification of patients prone to postoperative pain may be a step forward towards individualized pain medicine providing a basis for improved clinical management through treatment strategies targeting relevant pain mechanisms in each patient. Assessment of pain processing by quantitative sensory testing (QST) prior to surgery has been proposed as a method to identify patients at risk for postoperative pain, although results have been conflicting. Since the last systematic review, several studies investigating the association between postoperative pain and more dynamic measures of pain processing like temporal summation of pain and conditioned pain modulation have been conducted. Objectives According to the PRISMA guidelines, the aim of this systematic review was to evaluate whether assessment of experimental pain processing including measures of central pain mechanisms prior to surgery was associated with pain intensity after surgery. Methods Systematic database searches in PubMed and EMBASE with the following search components: QST, association, and postoperative pain, for studies that assessed the association between QST and pain after surgery were performed. Two authors independently reviewed all titles and abstracts to assess their relevance for inclusion. Studies were included if (1) QST was performed prior to surgery, (2) pain was assessed after surgery, and (3) the association between QST and pain after surgery was investigated. Forty-four unique studies were identified, with 30 studies on 2738 subjects meeting inclusion criteria. The methodological quality of the include studies was assessed and data extraction included study population, type of surgery, QST variables, clinical pain outcome measure and main result. Results Most studies showed moderate to high risk of bias. Type of surgery investigated include 7 studies on total knee replacement, 5 studies on caesarean section, 4 studies on thoracic surgery, 2 studies on herniotomy, 2 studies on hysterectomy/myomectomy, 1 study on tubal ligation, 1 study on gynecologic laparoscopy, 1 study on arthroscopic knee surgery, 1 study on shoulder surgery, 1 study on disc herniation surgery, 1 study on cholecystectomy,1 study on percutaneous nephrolithotomy,1 study on molar surgery, 1 study on abdominal surgery, and 1 study on total knee replacement and total hip replacement. The majority of the preoperative QST variables showed no consistent association with pain intensity after surgery. Thermal heat pain above the pain threshold and temporal summation of pressure pain were the QST variables, which showed the most consistent association with acute or chronic pain after surgery. Conclusions QST before surgery does not consistently predict pain after surgery. High quality studies investigating the presence of different QST variables in combination or along with other pain-related psychosocial factors are warranted to confirm the clinical relevance of QST prior to surgery. Implications Although preoperative QST does not show consistent results, future studies in this area should include assessment of central pain mechanisms like temporal summation of pressure pain, conditioned pain modulation, and responses to pain above the pain threshold since these variables show promising associations to pain after surgery.

Background Over the past couple of decades, a number of centers in the brain have been identified as important sites of nociceptive processing and are collectively known as the ‘pain matrix.’ Imaging tools such as functional magnetic resonance imaging (MRI) and 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography (PET) have played roles in defining these pain-relevant, physiologically active brain regions. Similarly, certain segments of the spinal cord are likely more metabolically active in the setting of pain conditions, the location of which is dependent upon location of symptoms. However, little is known about the physiologic changes in the spinal cord in the context of pain. This study aimed to determine whether uptake of 18 F-FDG in the spinal cord on positron emission tomography/computed tomography (PET/CT) of patients with low back pain (LBP) differs from that of patients without LBP. Methods We conducted a retrospective review of 18 F-FDG PET/CT scans of 26 patients with non-central nervous system cancers, 13 of whom had reported LBP and 13 of whom were free of LBP (controls). No patients had spinal stenosis or significant 18 F-FDG contribution of degenerative changes of the spine into the spinal canal. Circular regions of interests were drawn within the spinal canal on transaxial images, excluding bony or discal elements of the spine, and the maximum standardized uptake value (SUVmax) of every slice from spinal nerves C1 to S1 was obtained. SUVmax were normalized by subtracting the SUVmax of spinal nerve L5, as minimal neural tissue is present at this level. Normalized SUVmax of LBP patients were compared to those of LBP-free patients at each vertebral level. Results We found the normalized SUVmax of patients with LBP to be significantly greater than those of control patients when jointly tested at spinal nerves of T7, T8, T9 and T10 ( p < 0.001). No significant difference was found between the two groups at other levels of the spinal cord. Within the two groups, normalized SUVmax generally decreased cephalocaudally. Conclusions Patients with LBP show increased uptake of 18 F-FDG in the caudal aspect of the thoracic spinal cord, compared to patients without LBP. Implications This paper demonstrates the potential of 18 F-FDG PET/CT as a biomarker of increased metabolic activity in the spinal cord related to LBP. As such, it could potentially aid in the treatment of LBP by localizing physiologically active spinal cord regions and guiding minimally invasive delivery of analgesics or stimulators to relevant levels of the spinal cord.

Background and aims Pain is a multidimensional experience that is difficult to describe and to assess. To scale current pain, assessment refers to a maximum level of pain, but little is known about this process. Further, clinicians tend to underestimate patients’ pain, with or without patients’ own reports, and to underestimate to a greater extent with more clinical experience, possibly due to recalibration of a personal pain scale with increasing exposure to severe pain. We sought to determine how medical students rated pain in early years of clinical exposure, and in relation to experience of their own and others’ worst pains. Methods An online survey sampled medical students’ rating and description of their own worst pain and of that witnessed in another; also what would cause the maximum level of pain and what behaviours characterised it. Last, they indicated their preference among pain scales. Results Thirty-six medical students provided responses, the majority in their first six months of clinical exposure. Students’ own worst pain was rated a mean of 6.7/10 (s.d. 1.6) on a numerical scale; causes were diverse but with many bone fractures. Mean worst pain observed in another was rated 8.6/10 (s.d. 1.4); causes included fractures, gallstones, and sickle cell crises. Another’s worst pain was significantly higher (mean 9.4, s.d. 0.8 vs mean 8.0 s.d. 1.4) when rated after the student’s own pain than before it (presentation order randomised). We found no effect of clinical exposure on estimation of worst pain in another person, nor was there a personal tendency to rate pain using more or less extreme values. Students expected pain of 10/10 to be presented with many verbal, facial and whole body behaviours, and signs of physiological stress. Collectively, behavioural descriptions were rich and varied, but with many incompatibilities: for instance, between ‘writhing’ and ‘rigidity’ expected in the person with extreme pain. Most students preferred the numerical rating scale over visual analogue and verbal scales. Conclusions The study requires replication, particularly for clinical experience, where we found no significant difference in estimation of another’s pain over the first three years of medical students’ clinical exposure, but the comparison was underpowered. Despite no systematic individual difference in using pain ratings, there was a marked effect of rating another’s worst pain higher when the rater had previously rated his/her own worst pain. This suggests anchoring estimate of another’s pain in personal pain experience, and a possible way to mitigate clinicians’ underestimation of patients’ pain. Medical students’ recognition of the importance of facial expression in indicating another’s pain severity was encouraging, but most students anticipated only a narrow range of behaviours associated with extreme pain, thereby excluding other authentic behaviours. Implications Many clinical guidelines mandate regular pain assessment for hospital inpatients, and encourage routine assessment in community and outpatient settings, in order to decide on and monitor treatment. Replication and elaboration of this study could extend our understanding of how clinicians interpret pain scales completed by patients, and how they estimate patients’ pain.

Background and aim Opioid analgesics are often effective for pain management, but may cause constipation. The aim of this study was to determine healthcare resource use and costs in non-cancer and cancer patients with opioid-induced constipation (OIC). Methods This was a nationwide register-based cohort study including patients ≥18years of age initiating ≥4 weeks opioid therapy (1998–2012) in Denmark. Ameasure of OIC was constructed based on data from Danish national health registries, and defined as ≥1 diagnosis of constipation, diverticulitis, mega colon, ileus/subileus, abdominal pain/acute abdomen or haemorrhoids and/or ≥2 subsequent prescription issues of laxatives. Total healthcare resource utilization and costs (including pharmacy dispense, inpatient-, outpatient-, emergency room- and primary care) were estimated according to OIC status, opioid treatment dosage and length, gender, age, marital status, and comorbidities using Generalised Linear Model. Results We identified 97 169 eligible opioid users (77 568 non-cancer and 19 601 patients with a cancer diagnosis). Among non-cancer patients,15% were classified with OIC,10% had previous constipation, and 75% were without OIC. Patients characteristics of non-cancer OIC patients showed a higher frequency of strong opioid treatment (69% versus 41%), long-term opioid treatment (1189 days versus 584 days), advanced age (73 years versus 61 years), and cardiovascular disease (31%versus 19%) compared to those without OIC ( P < 0.001 for all comparisons). Non-cancer patients with OIC had 34% higher total healthcare costs compared to those without OIC ( P < 0.001) after adjusting for age, gender, opioid usage, marital status and comorbidities. Among cancer patients, 35% were classified with OIC,14% had previous constipation, and 51% were without OIC. A higher proportion of cancer patients with OIC were continuous opioid users (85% versus 83%) and strong opioid users (97% versus 85%), compared to those without OIC ( P <0.001 for both comparisons). Further, the mean number of days on opioids were higher for cancer patients with versus without OIC (329 days versus 238 days, P < 0.001). Total healthcare costs were 25% higher for cancer patients with versus without OIC ( P < 0.001) after adjusting for age, gender, opioid usage, marital status and comorbidities. Conclusions The results of this nationwide study based on real life data suggested that both non-cancer patients and cancer patients suffering from opioid-induced constipation (OIC) may have higher healthcare resource utilization and higher associated costs compared to those without OIC. Implications Reducing the number of OIC patients has potential cost savings for the health care system. Special attention should be on patients at potential high risk of OIC, such as strong and long-term opioid treatment, advanced age, and concomitant cardiovascular disease.

Background and purpose Research indicates that mirror therapy reduces phantom limb pain (PLP). Objectives were to determine when mirror therapy works in those who respond to treatment, the relevance of baseline PLP to when pain relief occurs, and what pain symptoms respond to mirror therapy. Methods Data from two independent cohorts with unilateral lower limb amputation were analyzed for this study ( n = 33). Mirror therapy consisted of 15-min sessions in which amputees performed synchronous movements of the phantom and intact legs/feet. PLP was measured using a visual analogue scale and the Short-Form McGill Pain Questionnaire. Results The severity of PLP at the beginning of treatment predicted when pain relief occurred. Those with low baseline PLP experienced a reduction ( p < 0.05) in PLP by session 7 of treatment, those with medium baseline PLP experienced pain relief by session 14 of treatment, and those with high baseline PLP experienced pain relief by session 21 of treatment. Mirror therapy reduced throbbing, shooting, stabbing, sharp, cramping, aching, tender, splitting, tiring/exhausting, and punishing-cruel pain symptoms. Conclusion The degree of PLP at baseline predicts when mirror therapy relieves pain. Implications This article indicates that the degree of baseline PLP affects when mirror therapy relieves pain: relief occurs by session 7 in patients with low PLP but by session 21 in patients with high PLP. Clinicians should anticipate slower pain relief in patients who begin treatment with high levels of pain.

In this issue of the Scandinavian Journal of Pain Kari Sørensen and Bjørg Christiansen publish their report on in depth interviews of young patients suffering from CRPS or from severe muscle pain [1]. These patients were recovering from their chronic pain conditions after treatment by a multidisciplinary rehabilitation team.

Background and aims Persistent (chronic) pain is a common phenomenon in adolescents. When young people are referred to a pain clinic, they usually have amplified pain signals, with pain syndromes of unconfirmed ethology, such as fibromyalgia and complex regional pain syndrome (CRPS). Pain is complex and seems to be related to a combination of illness, injury, psychological distress, and environmental factors. These young people are found to have higher levels of distress, anxiety, sleep disturbance, and lower mood than their peers and may be in danger of entering adulthood with mental and physical problems. In order to understand the complexity of persistent pain in adolescents, there seems to be a need for further qualitative research into their lived experiences. The aim of this study was to explore adolescents’ experiences of complex persistent pain and its impact on everyday life. Methods The study has an exploratory design with individual in-depth interviews with six youths aged 12–19, recruited from a pain clinic at a main referral hospital in Norway. A narrative approach allowed the informants to give voice to their experiences concerning complex persistent pain. A hermeneutic analysis was used, where the research question was the basis for a reflective interpretation. Results Three main themes were identified: (1) a life with pain and unpleasant bodily expressions; (2) an altered emotional wellbeing; and (3) the struggle to keep up with everyday life. The pain was experienced as extremely strong, emerging from a minor injury or without any obvious causation, and not always being recognised by healthcare providers. The pain intensity increased as the suffering got worse, and the sensation was hard to describe with words. Parts of their body could change in appearance, and some described having pain-attacks or fainting. The feeling of anxiety was strongly connected to the pain. Despair and uncertainty contributed to physical disability, major sleep problems, school absence, and withdrawal from leisure activities. Their parents were supportive, but sometimes more emotionally affected than themselves. The adolescents described how they strived for normality and to not become an outsider. Being met with necessary facilitation from school was important, as well as keeping up with friends. These adolescents had all been treated by an interdisciplinary pain team, and stated that they had an optimistic view of the future, despite still having some symptoms. Conclusions The study provides new insights into adolescents’ own experiences of complex persistent pain occurring unexpectedly, developing dramatically over time, and influencing all parts of their everyday lives. The adolescents entered vicious cycles, with despair and decreased physical and social functioning, with the risk of isolation and role-loss. However, these young people seem to have a strong motivation to strive for normalcy. Implications These findings may encourage healthcare providers to perceive adolescents’ persistent pain through the lenses of a biopsychosocial approach. We suggest that further research into adolescents with persistent pain should include longitudinal studies of quality of life and gender perspectives.

Background Bleeding into the vertebral canal causing a spinal haematoma (SH) is a rare but serious complication to central neuraxial blocks (CNB). Of all serious complications to CNBs such as meningitis, abscess, cardiovascular collapse, and nerve injury, neurological injury associated with SH has the worst prognosis for permanent harm. Around the turn of the millennium, the first guidelines were published that aimed to reduce the risk of this complication. These guidelines are based on known risk factors for SH, rather than evidence from randomised, controlled trials (RCTs). RCTs, and therefore meta-analysis of RCTs, are not appropriate for identifying rare events. Analysing published case reports of rare complications may at least reveal risk factors and can thereby improve management of CNBs. The aims of the present review were to analyse case reports of SH after CNBs published between 1994 and 2015, and compare these with previous reviews of case reports. Methods MEDLINE and EMBASE were used for identifying case reports published in English, German, or Scandinavian languages, using appropriate search terms. Reference lists were also scrutinised for case reports. Twenty different variables from each case were specifically searched for and filled out on an Excel spreadsheet, and incidences were calculated using the number of informative reports as denominator for each variable. Results Altogether 166 case reports on spinal haematoma after CNB published during the years between 1994 and 2015 were collected. The annual number of case reports published during this period almost trebled compared with the two preceding decades. This trend continued even after the first guidelines on safe practice of CNBs appeared around year 2000, although more cases complied with such guidelines during the second half of the observation period (2005–2015) than during the first half. Three types of risk factors dominated:(1) Patient-related risk factors such as haemostatic and spinal disorders, (2) CNB-procedure-related risks such as complicated block, (3) Drug-related risks , i.e. medication with antihaemostatic drugs. Conclusions and implications The annual number of published cases of spinal haematoma after central neuraxial blocks increased during the last two decades (1994–2015) compared to previous decades. Case reports on elderly women account for this increase.Antihaemostatic drugs, heparins in particular, are still major risk factors for developing post-CNB spinal bleedings. Other risk factors are haemostatic and spinal disorders and complicated blocks, especially “bloody taps”, whereas multiple attempts do not seem to increase the risk of bleeding. In a large number of cases, no risk factor was reported. Guidelines issued around the turn of the century do not seem to have affected the number of published reports. In most cases, guidelines were followed, especially during the second half of the study period. Thus, although guidelines reduce the risk of a post-CNB spinal haematoma, and should be strictly adhered to in every single case, they are no guarantee against such bleedings to occur.

Background Bleeding into the vertebral canal causing a spinal haematoma (SH) is a rare but serious complication to central neuraxial blocks (CNB). Of all serious complications to CNBs, neurological injury associated with SH has the worst prognosis. Around the turn of the millennium, the first guidelines aiming to reduce the risk of this complication were published. These guidelines are based on known risk factors for SH, rather than evidence from randomized, controlled trials (RCTs). RCTs, and hence meta-analysis of RCTs, are not appropriate for identifying rare events. Analysing data from a significant number of published case reports of rare complications may reveal risk factors and patterns undetectable in reports on occasional cases, and can thereby help to improve management of CNBs. The aims of the present review were to analyse case reports of SH after CNBs published between 1994 and 2015 with regard to diagnosis, treatment, and outcome of SH after CNB. Methods MEDLINE and EMBASE were utilized to find case reports published in English, German, or Scandinavian languages between 1994 and end of 2015, using appropriate search terms. Reference lists were also scrutinized for case reports. We documented initial and worst symptoms and signs of SH, diagnostic methods, treatment, and outcome of the SH. We calculated occurrences in per cent using the number of informative reports as denominator. Results One hundred and sixty-six case reports on spinal hematomas after CNB published during the years between 1994 and 2015 were identified. Eighty per cent of the patients had severe neurological symptoms (paresis or paralysis). When compared over time, outcomes have improved significantly. Among patients subjected to surgical evacuation of the hematoma, outcomes were best if surgery was performed within 12 hours from the firstsign of motor dysfunction. However, even patients operated after more than 24 hours had relatively favourable outcomes. Whereas the outcomes after surgical evacuation of the epidural haematomas were quite satisfactory, only one of the operations for subdural haematoma (SSDH) resulted in a favourable outcome. Conclusions and implications Suspicion of a spinal hematoma calls for the consultation of an orthopaedic or neurological surgeon without delay. MRI is the recommended diagnostic tool. Surgical evacuation within 12 h from the first sign of motor dysfunction seems to lead to the best outcome, although many patients operated as late as after more than 24 hours did regain full motor function. Despite the poor prognosis after surgical evacuation of SSDH, the outcomes after post-CNB spinal haematoma in general have improved significantly over time.

This topical review starts with a warning that despite an impressive wealth of neuroscientific data, a reductionist approach can never fully explain persistent pain. One reason is the complexity of clinical pain (in contrast to experimentally induced pain). Another reason is that the “pain system” shows degeneracy, which means that an outcome can have several causes. Problems also arise from lack of conceptual clarity regarding words like nociceptors, pain, and perception. It is, for example, argued that “homeoceptor” would be a more meaningful term than nociceptor. Pain experience most likely depends on synchronized, oscillatory activity in a distributed neural network regardless of whether the pain is caused by tissue injury, deafferentation, or hypnosis. In experimental pain, the insula, the second somatosensory area, and the anterior cingulate gyrus are consistently activated. These regions are not pain-specific, however, and are now regarded by most authors as parts of the so-called salience network, which detects all kinds of salient events (pain being highly salient). The networks related to persistent pain seem to differ from the those identified experimentally, and show a more individually varied pattern of activations. One crucial difference seems to be activation of regions implicated in emotional and body-information processing in persistent pain. Basic properties of the “pain system” may help to explain why it so often goes awry, leading to persistent pain. Thus, the system must be highly sensitive not to miss important homeostatic threats, it cannot be very specific, and it must be highly plastic to quickly learn important associations. Indeed, learning and memory processes play an important role in persistent pain. Thus, behaviour with the goal of avoiding pain provocation is quickly learned and may persist despite healing of the original insult. Experimental and clinical evidence suggest that the hippocampal formation and neurogenesis (formation of new neurons) in the dentate gyrus are involved in the development and maintenance of persistent pain. There is evidence that persistent pain in many instances may be understood as the result of an interpretation of the organism’s state of health. Any abnormal pattern of sensory information as well as lack of expected correspondence between motor commands and sensory feedback may be interpreted as bodily threats and evoke pain. This may, for example, be an important mechanism in many cases of neuropathic pain. Accordingly, many patients with persistent pain show evidence of a distorted body image. Another approach to understanding why the “pain system” so often goes awry comes from knowledge of the dynamic and nonlinear behaviour of neuronal networks. In real life the emergence of persistent pain probably depends on the simultaneous occurrence of numerous challenges, and just one extra (however small) might put the network into a an inflexible state with heightened sensitivity to normally innocuous inputs. Finally, the importance of seeking the meaning the patient attributes to his/her pain is emphasized. Only then can we understand why a particular person suffers so much more than another with very similar pathology, and subsequently be able to help the person to alter the meaning of the situation.

Objectives To examine the role of pain on cognitive function in adults with major depressive disorder (MDD). Methods Adults (18–65) with a Diagnostic and Statistical Manual – Fifth Edition (DSM-5)-defined diagnosis of MDD experiencing a current major depressive episode (MDE) were enrolled (n MDD = 100). All subjects with MDD were matched in age, sex, and years of education to healthy controls (HC) (n HC = 100) for comparison. Cognitive function was assessed using the recently validated THINC-integrated tool (THINC-it), which comprises variants of the choice reaction time (i.e., THINC-it: Spotter ), One-Back (i.e., THINC-it: Symbol Check ), Digit Symbol Substitution Test (i.e., THINC-it: Codebreaker ), Trail Making Test – Part B (i.e., THINC-it: Trails ), as well as the Perceived Deficits Questionnaire for Depression – 5-item (i.e., THINC-it: PDQ-5-D ). A global index of objective cognitive function was computed using objective measures from the THINC-it, while self-rated cognitive deficits were measured using the PDQ-5-D. Pain was measured using a Visual Analogue Scale (VAS). Regression analyses evaluated the role of pain in predicting objective and subjective cognitive function. Results A significant between-group differences on the VAS was observed ( p < 0.001), with individuals with MDD reporting higher pain severity as evidenced by higher scores on the VAS than HC. Significant interaction effects were observed between self -rated cognitive deficits and pain ratings ( p < 0.001) on objective cognitive performance (after adjusting for MADRS total score), suggesting that pain moderates the association between self-rated and objective cognitive function. Conclusions Results indicated that pain is associated with increased self-rated and objective cognitive deficits in adults with MDD. Implications The study herein provides preliminary evidence demonstrating that adults with MDD reporting pain symptomatology and poorer subjective cognitive function is predictive of poorer objective cognitive performance. THINC-it is capable of detecting cognitive dysfunction amongst adults with MDD and pain.