Volume 18, Issue 4

Background and aims Pain is a highly complex bio-psychosocial phenomenon that may present a (potential) health risk and either occurs as a warning sign or a symptom of injury. It cannot be ruled out that these rising or changing requirements in dance of all styles, are reflected in health-related outcomes such as pain. The aim of this narrative review article is to outline an overview of prevalence and localization, concepts of performance pain and injury pain, pain perception and pain management in dance. At that consequences of pain and influencing factors focusing on different dance styles or forms of professionalism are discussed. Methods The databases CINAHL, Cochrane, Google Scholar, Medline, MeSH and Web of Science were screened for relevant articles. Results Pain prevalence in dance is very high. Pain localizations can be related to high dance-specific mechanical stress on the musculoskeletal system. Depending on the pain characteristics, dancers perceive pain as “positive” (performance pain) or “negative” (injury pain). Concerning pain attitudes and management, dancers show an increasing pain tolerance. Pain seems to be accepted as a necessity, often ignored and dancing is continued despite pain. Conclusions The findings of this article suggest that occurrence of pain, pain perception, coping with pain and pain history appear to be connected to dance-specific mechanical stress as well as to socialization in dance culture. In dance, effects of pain on health seem to be associated with characteristics of pain and pain behavior. Implications The results highlight the high relevance of pain in dance and the need to take into account preventive as well as rehabilitative measures.

Background and aims The language in assessing intensity or quality of pain has been studied but the results have been inconsistent. The physicians’ language skills might affect the estimation of the severity of pain possibly leading to insufficient use of analgesics. Several interfering cultural factors have complicated studies aimed at exploring the language used to detect the quality of pain. We aimed to compare native and non-native language related qualitative aspects of pain chosen by Swedish speaking patients with diabetes. Methods In the study participated 10 Finnish and 51 Swedish speaking patients with diabetes. The Pain Detect-questionnaire was used for clarifying the patients’ pain and the mechanism of their pain (neuropathic or not) and for assessing the intensity and quality of pain. In addition, the patients completed the short-form McGill Pain Questionnaire (sfMPQ) in Finnish (test I). After 30 min the subjects completed the sfMPQ a second time in their native language (test II). The Swedish speakers estimated their second language, Finnish, proficiency on a 5-graded scale. Results There were significantly more discrepancies between sfMPQ test I and test II among the Swedish speaking respondents who reported poor (hardly none) Finnish language proficiency compared with those with good Finnish proficiency. Discrepancies occurred especially between the affective qualities of pain. Conclusions Poor second language proficiency exposes Swedish speakers to pain communication difficulties related to the affective aspects of pain. Consequently, discordant language communication could cause underestimation of the severity of pain and pain undertreatment. Implications To ensure adequate pain treatment measuring the affective dimension of pain in the patient’s native language is crucial.

Background and aims Breast cancer is the most prevalent adult cancer worldwide. A broader use of screening for early detection and adjuvant systemic therapy with chemotherapy has resulted in improved survival rates. Taxane-containing chemotherapy is one of the cornerstones of the treatment. However, taxane-containing chemotherapy may result in acute chemotherapy-induced nociceptive and neuropathic pain. Since this pain may be an additional burden for the patient both during and after taxane chemotherapy, it is important to rapidly discover and treat it. There is yet no gold standard for assessing taxane-induced pain. In the clinic, applying multiple methods for collecting information on pain may better describe the patients’ pain experiences. The aim was to document the pain during and after taxane through the contribution of different methods for collecting information on taxane-induced pain. Fifty-three women scheduled for adjuvant sequential chemotherapy at doses of ≥75 mg/m 2 of docetaxel and epirubicin were enrolled in the study. Methods Prospective pain assessments were done on a visual analog scale (VAS) before and during each cycle of treatment for about 5 months, and using the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire’s (EORTC-QLQ-C30) two pain questions at baseline, 3 months, and 12 months. Participants scoring pain on the VAS >30 and undergoing an interview also colored their pain on a body image during treatment and at 12 months. Results Surprisingly widespread, intense pain was detected using a multi-method approach. The colored body image showed pain being perceived on 51% of the body surface area during treatment, and on 18% 12 months after inclusion. In general, the pain started and peaked in intensity after the first cycle of taxane. After Cycle 3, most women reported an increase in pain on the VAS. Some women continued to report some pain even during the epirubicin cycles. The VAS scores dropped after the last chemotherapy cycle, but not to the baseline level. At baseline, 3 months and 12 months after inclusion, the women who estimated VAS >30 reported higher levels of pain on the pain questions of the EORTC-QLQ-C30. Conclusions This study contributes information on how different pain assessment tools offer different information in the assessment of pain. The colored body image brings another dimension to pain diagnostics, providing additional information on the involved body areas and the pain intensities as experienced by the women. A multi-method approach to assessing pain offers many advantages. The timing of the assessment is important to properly assess pain. Implications Pain relief needs to be included in the chemotherapy treatment, with individual assessment and treatment of pain, in the same way as is done in chemotherapy-triggered nausea. There is a time window whereby the risk of pain development is at its highest within 24–48 h after receiving taxane chemotherapy. Proper attention to pain evaluation and treatment should be in focus during this time window.

Background and aims Despite the recognition of pain as a global health problem and advancements achieved in what is known about effective pain management, pain education for undergraduate health care professionals remains insufficient. This study investigated the content of pain curricula and the time allocated to pain education on physiotherapy programs at bachelor’s level at Universities of Applied Sciences (UASs) in Finland. Methods A web-based survey questionnaire was sent to the directors of the physiotherapy programs at all the Finnish UASs ( n =15) where physiotherapy is taught at bachelor’s level. The questionnaire consisted of 14 questions covering basic concepts and the science of pain, pain assessment, pain management, and the adequacy of pain curricula. Each UAS completed one questionnaire i.e. returned one official opinion. Results The response rate was 80% ( n =12). The mean for the total number of contact hours of pain education was 74 (standard deviation 34.2). All UASs had integrated pain education. In addition to this 42% ( n =5) of the UASs had a separate pain course. The UASs offering such a course over and above the integrated pain education had twice the amount of pain content education compared to those UASs that only had integrated pain education (mean 103 h vs. 53 h, p =0.0043). Most of the education was devoted to conditions where pain is commonly a feature, manual therapy, and electrical agents for pain control. The biopsychosocial model of pain, cognitive behavioral methods of pain management, physician management, and multidisciplinary management were the least covered topics. Five UASs (42%) payed attention to the International Association for the Study of Pain curriculum outline and only 33% ( n =4) considered their pain education to be sufficient. Conclusions Our results indicate that more contact hours are devoted to pain education on the Finnish UASs’ physiotherapy programs at bachelor’s level, than has previously been reported in faculty surveys. A separate pain course is one way to ensure a sufficient amount of pain education. Overall, despite a sufficient time devoted to pain education, some essential pain contents were inadequately covered. Implications The study contributes information on how pain education can be organized on physiotherapy programs at undergraduate level. Besides a sufficient amount of pain education, which can be ensured by a separate pain course, attention should be paid to pain education content being up-to-date. This could help in estimating the different proportions of pain content needed in educational settings. Efforts should also be made at keeping integrated pain education well-coordinated and purposeful. There is a need for further research estimating the effectiveness of pain education according to the different ways in which it is organized. There is also a need to investigate whether more hours allocated to pain education results in better understanding and professional skills.

Background and aims The aim of the study was to examine the effect of mirror and tactile therapy on phantom and stump pain in patients with traumatic amputations, with particular reference to amputees in low-income communities. Methods The study was conducted with an open, randomized, semi-crossover case-control design in rural Cambodia. A study sample of 45 landmine victims with trans-tibial amputations was allocated to three treatment arms; mirror therapy, tactile therapy, and combined mirror-and-tactile therapy. Non-responders from the mono-therapy interventions were crossed over to the alternative intervention. The intervention consisted of 5 min of treatment every morning and evening for 4 weeks. Endpoint estimates of phantom limb pain (PLP), stump pain, and physical function were registered 3 months after the treatment. Results All three interventions were associated with more that 50% reduction in visual analogue scale (VAS)-rated PLP and stump pain. Combined mirror-tactile treatment had a significantly better effect on PLP and stump pain than mirror or tactile therapy alone. The difference between the three treatment arms were however slight, and hardly of clinical relevance. After treatment, the reduction of pain remained unchanged for an observation period of 3 months. Conclusions The study documents that a 4-week treatment period with mirror and/or tactile therapy significantly reduces PLP and stump pain after trans-tibial amputations. Implications The article reports for the first time a randomized controlled trial of mirror therapy in a homogenous sample of persons with traumatic amputations. The findings are of special relevance to amputees in low-resource communities.

Background and aims Pain, use of painkillers and alcohol are highly prevalent in the general population. Aims of the study were to describe differences in pain, alcohol consumption and use of painkillers among two 60 year old birth cohorts stratified by gender. Methods Participants were recruited from the Skåne centre of The Swedish National study on Aging and Care, a multicentre, prospective, longitudinal study. The sample comprised 60 year old men and women born between 1941 and 1943 and recruited to the study between 2001 and 2004 ( n =663) and 60 year old men and women born in the period 1952–1954 and recruited to the study between 2013 and 2015 ( n =924). Specially trained research staff conducted the interviews. For descriptive statistics the variables were presented in total numbers, percentages, mean and standard deviation, and 1st and 3rd quartile are also shown. The sample was divided into four groups: men and women born in the period 1941–1943, men and women born in the period 1952–1954, respectively. Results No difference in alcohol intake was detected between the two birth cohorts. All participants, regardless of pain or not, reported alcohol use below the specified risk level for both sexes. Teetotallers were more common in the 1952–1954 male cohort, 128 (29%), p <0.029. Two hundred and eighty one Men born between 1952 and 1954 reported pain (59.0%), compared to 173 men born between 1941 and 1943 (51.6%), p <0.034. There was no difference between the male cohorts in use of painkillers, p <0.062. No difference was found between the two female cohorts in terms of pain, p <0.144. One hundred and ten women in the 1941–43 cohort used painkillers (53.1%) compared to 119 women born between 1952 and 1954 (40.1%), p <0.004. When comparing men and women with pain born between 1941 and 1942, men with moderate pain use more alcohol, 157 g/month (q1 10, q3 365) than women, 44 g/month (q1 0, q3 134), p <0.001. Men with severe pain also use more alcohol, 96 g/month (q1 17, q3 324) than women, 27 g/month (q1 0, q1 118), p <0.030, and when those with pain were merged into a group, men use more alcohol, 175 g/month (q1 31, q3 356), than women, 68 g/month (q1 1, q3 207), p <0.001. This also applies to the later cohort; men, 132 g/month (q1 22, q3 270), compared to women, 76 g/month (q1 8, q3 182), p <0.001. When merging all pain into one group women use more painkillers both in the 1941–43 cohort, men (39.9%) compared to women (53.1%), p <0.010 and in the 1952–54 cohort, men (18.5%) compared to women (26.6%), p <0.003. Use of analgesics and alcohol is common but the highest percentage is among women born between 1941 and 1943, 45 (48.9%). Conclusions Pain and alcohol use are common among 60 year old women and men. A gender difference is that women use more painkillers. In the 1941–43 cohort almost every second woman with moderate pain who took painkillers also consumed alcohol. Implications It is time to alert prescribers that a large section of the population uses alcohol combined with painkillers. More research is needed to better understand the long-term perspective on health when using both painkillers and alcohol.

Background and aims Musculoskeletal pain among adolescents is a problem for the patients and their families and has economic consequences for society. The aim of this study is to determine the incidence of prolonged disabling musculoskeletal pain of adolescents among referrals to a pediatric rheumatology outpatient clinic and describe the patient material. The second aim is to find proper screening tools which identifies patients with a risk of pain chronification and to test whether our patients fit the Pediatric Pain Screening Tool (PPST) stratification according to Simons et al. Methods We selected adolescent patients with disabling, prolonged, musculoskeletal pain and calculated the incidence. Furthermore, after the patient collection, we adjusted our pain patients to PPST. Results The incidence of prolonged musculoskeletal pain patients at our clinic was 42/100,000 patient years (pyrs) (age 13–18; 95% CI: 29–60) during years 2010–2015. A nine-item screening tool by Simons et al. proves to be valid for our patient group and helps to identify those patients who need early, prompt treatment. The functional risk stratification by Simons et al. correlates with our patients’ functional disability. Conclusions and implications In order to prevent disability and to target intervention, it is necessary to have proper and rapid screening tools to find the appropriate patients in time.

Background and aims The recent economic crisis started in the USA in 2008 but quickly had worldwide impact. Ireland, Greece, and Portugal were in economic distress in 2009 and received rescue monetary packages from the European Union (EU) and the International Monetary Fund (IMF) in the following years. Meanwhile, the economic recovery has begun for those countries, but at different paces. The aim of the present study was to evaluate if the economic crisis influenced pain research outcomes, by performing a bibliometric analysis based on the ISI Web of Science to evaluate the evolution of the scientific production and performance in the field of pain research between 1997 and 2017. Methods Articles search was conducted using the ISI Web of Science, search keywords “pain or nocicep*”, between 1997 and 2017, and one author affiliated in an Irish, Greek or Portuguese institution. The total number of published articles per country, total citations, h-index, document types and authors’ institution were tabulated to determine the quantity and quality of the publications in this field. Results The search retrieved 2,368 publications over the 20 years’ period, increasing from 26 in 1997 to 230 in 2017. The number of Irish publications per year increased steadily along the studied period, while the number of Greek publications stabilized from 2008 onward and Portuguese publications started to increase only in 2007 but declined slightly after 2014. In total, Irish authors published 1,143 articles, Greek authors 624 and Portuguese authors 618. There were nine articles with more than 100 citations, and Irish publications had a higher h-index (52) than Greek’s (45) or Portuguese’s (36) publications. Ireland had the highest number of pain publications per capita, but in 2016 Portugal had the lowest cost per publication, as measured by the GDP per capita per publication (in 1997 Portugal had the highest cost). The three major research fields of the publications were neurosciences/neurology (19%), general internal medicine (16%) and anaesthesiology (13%), and the affiliation institutions were mostly universities or universities hospitals. Conclusions The number of Irish, Greek, and Portuguese pain publications increased between 1997 and 2017, but at different paces. It appears that the economic crisis had no impact on the rate of pain publications in Ireland, had a delayed impact in Portugal, and affected mostly Greek pain scientific research. This may be related to the fact that Greece was the country that received more rescue packages and where the economic crisis was deepest and lasted longer. Implications Economics and scientific production have a mutual influence: usually research investment decreases in recession times (reducing grants and scientific employment), but health scientific production can improve health and quality of life and also benefit the economy. So in crisis periods, governments should create means to protect and foster scientific work.

Background and aims The subjective nature of pain makes objective, quantitative measurements challenging. The current gold standard for evaluating pain is patient self-reporting using the numeric rating scale (NRS) or Visual Analog Scale. Skin conductance responses per second (SCR) measured in the palmar region reflect the emotional part of the autonomous nervous system. SCR ≥0.20 have been shown to indicate moderate or severe pain in the postoperative setting. We examined whether SCR can detect procedure-related pain before major surgery. Methods In 20 patients being prepared for major surgery SCR was recorded before and during arterial cannulation, after induction of anaesthesia, and on the first postoperative day. Self-reported pain was evaluated using NRS. NRS >3 was considered to represent moderate or severe pain. Results NRS was 0 [0–0] before arterial cannulation, increasing to 5 [3–6] during arterial cannulation ( p <0.05). Before arterial cannulation SCR was 0.27 [0.20–0.27], increasing to 0.33 [0.30–0.37] during arterial cannulation ( p <0.01). On the first postoperative day both SCR and reported pain indicated no more than mild pain, SCR 0.13 [0.00–0.20] and NRS 2.0 [0.5–2.0]. The sensitivity of SCR to indicate moderate or severe pain (NRS >3) was 0.93 (0.68–1.0) and specificity was 0.33 (0.25–0.35) when the cut-off established in the postoperative setting (SCR ≥0.20) was used on all data. Conclusions SCR increased during arterial cannulation. Before major surgery the SCR was above the threshold demonstrated to indicate pain in the postoperative setting, even without painful stimuli and no reported pain. Using the threshold established for postoperative pain, SCR cannot reliably discriminate between pain and other stressors before major surgery. Implications Before major surgery, the diagnosis of moderate or severe pain should not be made based on SCR ≥0.20.

Background and aims Acute pain is differentiated from chronic pain by its sudden onset and short duration; in contrast, chronic pain is characterized by a duration of at least several months, typically considered longer than normal healing time. Despite differences in definition, there is little information on how types of self-management strategies or outcomes differ when pain is chronic rather than acute. Additionally, age and gender are thought to be related to types of strategies used and outcomes. However, strategies used and outcomes can be influenced by level of education, socioeconomic status, occupation, and access to the health care system, which can confound associations to type of pain, age or gender. The purpose of this study was to examine the association of strategies used for pain self-management and outcomes with type of pain, acute or chronic, age, or gender in a socioeconomically homogenous population, pharmacists. Methods Pharmacists with acute or chronic pain and a valid email completed an on-line questionnaire on demographic characteristics, pain characteristics, pharmacological and non-pharmacological strategies for managing pain, and outcomes (e.g. pain intensity). Univariate analysis was conducted by stratifying on type of pain (acute or chronic), then stratifying on gender (men vs. women) and age (younger vs. older). The a priori alpha level was 0.05. Results A total of 366 pharmacists completed the questionnaire, 212 with acute pain (average age=44±12.1; 36% men) and 154 with chronic pain (average age=53±14.0; 48% men). The chronic pain group reported substantially higher levels of pain before treatment, level of post-treatment pain, level of pain at which sleep was possible, and goal pain levels (effect sizes [ES’s]=0.37–0.61). The chronic pain group were substantially more likely to use prescription non-steroidal anti-inflammatory medications (NSAIDS), opioids, and non-prescription pain relievers (ES’s=0.29–0.80), and non-medical strategies (ES’s=0.56–0.77). Participants with chronic pain also were less confident (ES=0.54) and less satisfied (ES=0.52). In contrast, there were no differences within either the acute or chronic pain groups related to gender and outcomes. In the acute pain group, there also were no gender differences related to management strategies. However, younger age in the acute pain group was associated with use of herbal remedies and use of rest. Within the chronic pain group, men were more likely to use NSAIDS and women more likely to use hot/cold packs or massage while older participants were more likely to use massage. Variability in post-treatment level of pain and percent relief was high in all groups (coefficient of variation=25%–100%). Conclusions The differences between acute and chronic pain were substantial and included differences in demographic characteristics, pain characteristics, management strategies used, and outcomes. In contrast, few associations between age and gender with either management strategies or outcomes were identified, although the variability was high. Implications When managing or researching pain management, acute pain should be differentiated from chronic pain. Because of the substantial variability within the gender and age groups, an individual approach to pain management irrespective of age and gender may be most useful.

Background and aims Despite the enormous body of literature spanning more than 50 years describing results of pain experiments, very few have used qualitative methods to explore subjects’ thoughts while scoring experimental painful stimuli, and none in the available literature have used qualitative interviews to do so. The current study examined how participants in experimental pain research delineate pain ratings to better understand the unique influences of the experimental setting on pain scores. An additional aim was to highlight how individuals with fibromyalgia and healthy volunteers are differently influenced by characteristics of the experimental setting. Methods This was an inductive, qualitative study in which individual, semi-structured interviews were performed with 31 fibromyalgia patients and 44 healthy volunteers. Participants had taken part in a pain experiment during which a thermode was used to induce painful heat stimuli on two skin areas. There were two primary interview questions analyzed for this report: (1) “Thinking back to when you were getting the heat pain on your leg, what were you thinking about when deciding on your pain score?” and (2) Participants who said that it was difficult to decide on a pain score were asked to, “Describe what made it difficult to choose a number.” Thematic analysis was used to generate conceptual categories from textual data and find common themes. Results Three notable differences were found between fibromyalgia patients and healthy volunteers: (1) using current daily pain as a benchmark was seen more in patients, (2) wanting to appear strong in front of the study investigators was more common in healthy volunteers, and (3) becoming mentally fatigued from rating many stimuli was more common for fibromyalgia patients. Thoughts while scoring pain included: (1) comparing with previous or current pain, (2) self-monitoring of one’s ability to endure the pain, (3) focusing on the physical aspects of the pain, (4) knowing the experimental setting is safe, (5) focusing on the pain scale as an anchor, and (6) desire to appear strong. Additionally, five difficulties in scoring experimental pain were identified: (1) falling asleep, (2) mentally fatigued, (3) feeling as though they were guessing, (4) having to make a quick decision, and (5) difficulty in being consistent. Conclusions This study provides insights into the thoughts of participants in experimental pain research studies. Participants were distracted and influenced by the experimental setting and some factors differed for fibromyalgia patients versus healthy volunteers. Implications Understanding the ways in which the experimental setting influences pain ratings may help pain researchers better design and interpret studies. Researchers can use these findings to mitigate difficulties for participants in experimental research to add to its validity.

Background and aims Dextropropoxyphene (DXP) is a synthetic opioid that was prescribed worldwide for mild to moderate pain. It was withdrawn from the European market in 2009. In this study we aim to investigate the effect of the market withdrawal of dextropropoxyphene in Norway on overall use of opioids and other analgesics at an individual level. Methods Data were collected from the nationwide Norwegian Prescription Database (NorPD). It covers all prescription of drugs from 01 January 2004 from Norwegian pharmacies dispensed to individuals outside institutions. The study period was divided in two 2-year periods from 01 September 2008 to 31 August 2010, and from the market withdrawal of DXP on 01 September 2010 to 31 August 2012. We included every individual that filled at least one prescription of dextropropoxyphene in the first 2-year period in our study population. In this study dextropropoxyphene, codeine and tramadol are defined as “weak opioids”, and all other opioids are termed “strong opioids”. Results Nine thousand one hundred and seventy-one individuals were included in our study population. Four thousand two hundred and ninety filled a prescription of DXP only once and were classified as “single users”, 2,990 were users with prescriptions of up to 200 defined daily doses (DDD) over the first 2-year period, or “sporadic users”, and 1,886 were classified high users with over 200 DDDs over a 2-year period. After the market withdrawal 8,392 continued to be prescribed analgesics or benzodiazepines. In the single user group, the proportion of users of weak opioids decreased from 69.5% to 57.6%, whereas the proportion of users of strong opioids was unchanged. Among the sporadic user group, the proportion of users of weak opioids went from 69.7% to 71.0%, the proportion using tramadol from 39.1% to 43.9%, and the users of strong opioids from 25.8% to 31.3%. In the high user group, there was an increase in the number of users of strong opioids from 37.8% to 51.4%. The amount of strong opioids prescribed in the high user group increased from a mean of 262.5 DDD to a mean of 398.3 DDD in the following 2 years. The amount of tramadol increased in all groups and was 3 times as high in the high user group after market withdrawal of DXP. Conclusions Our study showed that the withdrawal of DXP lead to an increase in prescription of other analgesics. The proportion of users increased in all three groups and so did the prescribed amount of other analgesics. Both the proportion of users of other opioids and the amount prescribed increased considerably. However, 1 in 10 earlier users of DXP stopped using prescribed analgesics altogether in the following 2 years. The increase in use among earlier high users of DXP was most striking. Implications This study documents markedly increased prescriptions of other opioids after withdrawal of dextropropoxyphene due to its high risk of serious complications. However, consequences of the increased use of opioids among earlier high users of DXP such as changes in risk of poisonings, accidental deaths and suicides remain to be investigated.

Background and aims Insights into the nature of cognitive bias, including attentional bias to threat signals, are considered pivotal to understanding (chronic) pain and related distress. It has been put forward that attention to pain-related threat is normally dynamic and relates to the motivational state of the individual. In this experiment we aimed (i) to replicate the finding that attentional bias for pain signals in healthy participants can be reduced when a non-pain goal is pursued, and (ii) to extend this finding by taking into account the outcome focus of the non-pain goal. We hypothesised that the reduction in attentional bias for pain signals by concurrent non-pain goal pursuit would be stronger with non-pain prevention goals than with promotion goals. Methods Healthy university students performed an attentional bias task (i.e. spatial cueing task) containing visual cues that signalled the possible occurrence of a painful stimulus (electrocutaneous stimulus at tolerance level) or its absence, in combination with a non-pain goal task (i.e. digit naming task). The non-pain goal was either related to acquiring a positive outcome (gaining money depending on digit-naming performance; promotion goal group, n = 31 ) or related to avoiding a negative outcome (losing money; prevention goal group, n = 31 ). A standard attentional bias task served as the control condition ( control group, n = 31 ). Results Spatial cueing effects were larger for pain cues than for no-pain cues, indicating attentional bias for pain signals. The pattern of results suggests that this effect was indeed reduced in the goal groups as compared to the control group, but there was no significant group difference. Conclusions We found no statistically-significant evidence for the impact of non-pain goal pursuit or outcome focus on pain-related attentional bias. At best, there were indications of a reduced attentional bias for pain signals with non-pain goal pursuit that was either promotion- or prevention focused. Implications These data add to the small but growing body of literature on the assumed relevance of motivational context in explaining variations in attentional bias. The results trigger new questions on the nature and assessment of pain-related attentional bias, and more specifically attentional bias for fear-conditioned pain signals (versus safety signals), from a motivational perspective.

Background and aims The clinical management of neuropathic pain remains a challenge. We examined the interaction between gabapentin and NMDA receptor antagonists dextromethrophan and MK-801 in alleviating neuropathic pain-like behaviors in rats after spinal cord or sciatic nerve injury. Methods Female and male rats were produced with Ischemic spinal cord injury and sciatic nerve injury. Gabapentin, dextromethorphan, MK-801 or drug combinations were injected with increasing doses. Mechanical response thresholds were tested with von Frey hairs to graded mechanical touch/pressure, and ethyl chloride spray was applied to assess the cold sensitivity before and after injuries. Results In spinally injured rats, gabapentin and dextromethorphan did not affect allodynia-like behaviors at doses of 30 and 20 mg/kg, respectively. In contrast, combination of 15 or 30 mg/kg gabapentin with dextromethorphan at 10 mg/kg produced total alleviation of allodynia to mechanical or cold stimulation. Further reducing the dose of gapapentin to 7.5 mg/kg and dextromethorphan to 5 mg/kg still produced significant effect. MK-801, another NMDA receptor antagonist, also enhanced the effect of gabapentin in spinally injured rats. Similar synergistic anti-allodynic effect between dextromethorphan and gabapentin was also observed in a rat model of partial sciatic nerve injury. No increased side effect was seen following the combination between gabapentin and dextromethorphan. Conclusions In conclusion, the present study suggested that combining NMDA receptor antagonists with gabapentin could provide synergistic effect to alleviate neuropathic pain and reduced side effects. Implications Combining NMDA receptor antagonists with gabapentin may provide a new approach in alleviating neuropathic pain with increased efficacy and reduced side effects.

Background and aims Offset analgesia (OA) is a pain modulating mechanism described as a disproportionately large decrease in pain intensity evoked by a minor decrease in stimulus intensity. Precise mechanisms of OA are still not elucidated and studies are needed to evaluate factors modulating OA. The aim of this study was to investigate OA before and during tonic cold pain (thought to induce descending inhibition), in a group of healthy volunteers. Methods A randomized, crossover study was performed in 17 healthy participants (8 males and 9 females). The OA paradigm lasted 35 s and was induced by the traditional method using thermal stimulation applied to the forearm. A constant control heat stimulus (CTL) paradigm was used as control to assess adaptation. Pain intensity was assessed continuously. For induction of tonic cold pain, the participants immersed their hand into 2°C water for 2 min. After 1 min and 25 s, the heat stimulation (OA or CTL paradigm) was repeated to assess the modulatory effect of the cold pressor test. Results It was possible to induce OA both before and during the cold pressor test. Tonic cold pain modulated the peak pain reported during both the OA ( p =0.015) and CTL paradigms ( p =0.001) reflecting endogenous pain modulation. However, the magnitude of OA was not modulated by tonic cold pain ( p >0.05). Conclusions The offset analgesia magnitude was not modulated by simultaneously tonic cold pain, thought to reflect another endogenous pain modulation mechanism. Implications Neither offset analgesia magnitude nor adaptation were modulated by cold pressor induced endogenous analgesia. This could be explained by the fact, that offset analgesia was already at maximum in healthy participants. Hence, offset analgesia may not be a suitable assessment tool to investigate modulation induced by experimental methods or pharmacology in healthy participants.

Background and aims The participation in ultra-marathons and other ultra-endurance events has increased exponentially over the past decade. There is insufficient data on variation in pain mechanisms in exercise overall but especially in the ultra-endurance athlete population. To further understand peripheral and central pain sensitization we have investigated pressure pain threshold and conditioned pain modulation during three separate ultra-marathon competitions. Methods Each ultra-marathon investigated was held in the state of Florida, USA, over flat, sandy and paved surfaces under generally warm to hot, humid conditions. Pressure pain threshold was measured utilizing a Baseline © Dolorimeter. The blunt end of the dolorimeter stylus was placed onto the distal dominant arm, equidistant between the distal radius and ulna, three times in a blinded manner to insure that the testing technician did not influence the subject’s responses. Conditioned pain modulation was measured immediately after the PPT measures by placing the non-dominant hand in a cool water bath maintained at 15°C. The same dolorimeter measurement was repeated two more times on the dominant arm while the non-dominant hand remained in the water. Data was analyzed with a paired t -test. Results Pressure pain threshold was significantly decreased ( p <0.05) at 25, 50 and 100 miles. Conditioned pain modulation was also significantly decreased ( p <0.05) at 25, 50 and 100 miles of an ultra-marathon competition. Conclusions Together these data suggest an increased peripheral and/or central pain sensitization starting at 25 miles and continuing throughout an ultra-marathon competition run in these conditions. This is the first study that provides evidence of a decreased peripheral pain threshold and decreased central pain inhibition from ultra-marathon running. Decreases in both the peripheral pain threshold and central inhibition may result from nociceptor plasticity, central sensitization or a combination of both. Implications Based on previous research that has indicated a central sensitization resulting from inflammation and the well-documented inflammatory response to the rigors of ultra-marathon competition, we suggest the decreased peripheral pain threshold and decreased descending pain inhibition results from this inflammatory response of running an ultra-marathon.

Background and aims Chronic pain is affecting a growing number of individuals including adolescents. Different endogenous pain inhibitory systems could confer protection against development of chronic pain. Decreased pain perception can be observed following intense pain (i.e. conditioned pain modulation – CPM) or after physical exercise (i.e. exercise-induced analgesia – EIA). Reduced effectiveness of pain inhibitory mechanisms have been reported in several chronic pain conditions. However, the extent of these dysfunctions has not been thoroughly investigated in adolescents suffering from chronic pain. Our hypothesis was that adolescents suffering from chronic pain have less effective CPM and EIA than pain-free teenagers. Methods Twenty-five healthy adolescent girls and 16 teenage girls with chronic pain participated in this study. Only girls were included in this investigation, since chronic pain is more prevalent in females. The effectiveness of CPM was assessed by comparing heat pain stimulations (individually adapted to induce mild pain intensity) performed with a thermode before and after a cold pressor test (CPT; 2 min, 10 °C). EIA was evaluated by comparing pain intensity produced by an ice cube placed on the forearm before and after a graded exercise test on a cycle ergometer. Results Pain intensity produced by heat pain stimulations decreased following CPT in healthy ( p <0.05), but not in chronic pain adolescent girls ( p =0.4). Pain intensity induced by the ice cube was reduced after exercise in healthy ( p <0.05), but not in chronic pain adolescents ( p =0.9). The effectiveness of CPM and EIA was inferior in teenage girls suffering from chronic pain compared to healthy participants ( p <0.05). Conclusions Endogenous pain inhibitory mechanisms triggered by intense pain or by physical exercise are effective in healthy adolescent girls. Teenage girls living with chronic pain do not show diminished pain perception after a CPT or a graded exercise test. These results suggest that pain inhibitory mechanisms such as CPM and EIA are ineffective in adolescent girls suffering from chronic pain. Implications In a wider context, the findings of the present research could help understand better the mechanisms involved in the development of chronic pain. Improved comprehension of this subject might help prevent chronic pain conditions and thus, reduce the negative impacts of this burden.

Background and aims Despite lack of support from recent in vivo studies, bending and lifting (especially with a round-back posture) are perceived as dangerous to the back. In light of this view, it has been proposed that pain-free people may hold a common implicit belief that is congruent with the idea that bending and lifting with a round-back represents danger to a person’s back, however this has not been evaluated. The aims of this study were: (1) to evaluate implicit associations between back posture and safety related to bending and lifting in pain-free people; (2) to explore correlations between the implicit measure and explicit measures of back beliefs, fear of movement and safety of bending; (3) to investigate self-reported qualitative appraisal of safe lifting. Methods Exploratory cross-sectional study including 67 pain-free participants (no pain, or average pain ≤3/10 for less than one week over the previous 12 months) (52% male), who completed an online survey containing demographic data and self-reported measures of: fear of movement (Tampa Scale for Kinesiophobia for General population – TSK-G), back beliefs (Back Pain Attitudes Questionnaire BackPAQ), and bending beliefs (Bending Safety Belief – BSB – a pictorial scale with images of a person bending/lifting with round and straight back postures). Implicit associations between back posture and safety related to bending and lifting were evaluated with the Implicit Association Test (IAT). A qualitative assessment of descriptions of safe lifting was performed. Results An implicit association between “danger” and “round-back” bending/lifting was evident in all participants (IAT D-score =0.65 (SD=0.45; 95% CI [0.54, 0.76]). Participants’ profile indicated high fear of movement, unhelpful back beliefs, and perceived danger to round-back bending and lifting (BSB Thermometer : 5.2 (SD=3.8; 95% CI [4.26, 6.13] range −10 to 10; t (67) =11.09, p <0.001). There was a moderate correlation between IAT and BSB Thermometer (r=0.38, 95% CI [0.16, 0.62]). There were weaker and non-statistically significant correlations between IAT and TSK-G (r=0.28, 95% CI [−0.02, 0.47]), and between IAT and BackPAQ Danger (r=0.21, 95% CI [−0.03, 0.45]). Qualitative assessment of safe lifting descriptions indicated that keeping a “straight back” and “squatting” when lifting were the most common themes. Conclusions Pain-free people displayed an implicit bias towards bending and lifting with a “round-back” as dangerous. Our findings support the idea that pain-free people may have a pre-existing belief about lifting, that the back is in danger when rounded. Research to evaluate the relationship between this implicit bias and lifting behaviour is indicated. Implications The findings of this study may have implications for ergonomic guidelines and public health information related to bending and lifting back postures. Additionally, clinicians may need to be aware of this common belief, as this may be reflected in how a person responds when they experience pain.

Background and aims Conditioned Pain Modulation (CPM) is a well-established phenomenon and several protocols have shown acceptable between-subject reliability [based on intraclass correlation coefficient (ICC) values] in pain-free controls. Recently, it was recommended that future CPM test-retest reliability studies should explicitly report CPM reliability based on CPM responders and non-responders (within-subject reliability) based on measurement error of the test stimulus. Identification of reliable CPM paradigms based on responders and non-responders may be a step towards using CPM as a mechanistic marker in diagnosis and individualized pain management regimes. The primary aim of this paper is to investigate the frequency of CPM responders/non-responders, and to quantify the agreements in the classification of responders/non-responders between 2 different days for 10 different CPM protocols. Methods Data from a previous study investigating reliability of CPM protocols in healthy subjects was used. In 26 healthy men, the test-stimuli used on both days were: Pain thresholds to electrical stimulation, heat stimulation, manual algometry, and computer-controlled cuff algometry as well as pain tolerance to cuff algometry. Two different conditioning stimuli (CS; cold water immersion and a computer-controlled tourniquet) were used in a randomized and counterbalanced order in both sessions. CPM responders were defined as a larger increase in the test stimulus response during the CS than the standard error of measurement (SEM) for the test-stimuli between repeated baseline tests without CS. Results Frequency of responders and non-responders showed large variations across protocols. Across the studied CPM protocols, a large proportion (from 11.5 to 73.1%) of subjects was classified as CPM non-responders when the test stimuli standard error of measurements (SEM) was considered as classifier. The combination of manual pressure algometry and cold water immersion induced a CPM effect in most participants on both days ( n =16). However, agreement in the classification of CPM responders versus non-responders between days was only significant when assessed with computer-controlled pressure pain threshold as test-stimulus and tourniquet cuff as CS (κ=0.36 [95% CI, 0.04–0.68], p =0.037). Conclusions and implications Agreements in classification of CPM responders/non-responders using SEM as classifier between days were generally poor suggesting considerable intra-individual variation in CPM. The most reliable paradigm was computer-controlled pressure pain threshold as test-stimulus and tourniquet cuff as conditioning stimulus. However while this CPM protocol had the greatest degree of agreement of classification of CPM responders and non-responders across days, this protocol also failed to induce a CPM response in more than half of the sample. In contrast, the commonly used combination of manual pressure algometry and cold water immersion induced a CPM effect in most participants however it was inconsistent in doing so. Further exploration of the two paradigms and classification of responders and non-responders in a larger heterogeneous sample also including women would further inform the clinical usefulness of these CPM protocols. Future research in this area may be an important step towards using CPM as a mechanistic marker in diagnosis and in developing individualized pain management regimes.

Cerebrospinal fluid cutaneous fistula is a rare but potentially serious complication of epidural analgesia. We report the case of a patient submitted to total knee arthroplasty under subarachnoid block and placement of lumbar epidural catheter for post-operative analgesia. The epidural catheter was found exteriorised on the fourth post-operative day, and the patient presented with a moderate fluid leak from the puncture site that was confirmed to be cerebrospinal fluid by cytological and chemical analysis. The initial therapeutic approach consisted of bed rest, hydration and prophylactic antibiotic therapy for 3 days, but it was ineffective as the leak persisted. A suture was placed at the epidural insertion site with immediate resolution of the leak. The suture was maintained for 5 days. The patient progressed satisfactorily without requiring further therapies.

Background and aims A previously undescribed mechanism of pain in the ulnar side of the hand was observed in a series of four patients. All were found to have a sensitive point in the first interspace of the hand and possible entrapment of a terminal branch of ulnar nerve piercing the fascia in the first interphalangeal webspace was suggested. Methods Pressure on the sensitive point reproduced the ulnar sided hand pain. Diagnostic and therapeutic injection of the mixture of local anesthetic and corticosteroid were performed. The degree and duration of relief of pain was noted. Results In individuals with recent onset hand pain of this type the injections abolished pain for 2 or more years. In individuals with long-standing pain (longer than 3–6 months) the pain was abolished for periods of time lasting several hours to several weeks. The correspondence of the point, where injections were done with acupuncture point LI4 was noted. Conclusions The location of possible nerve entrapment corresponds with an acupuncture point LI4 and may additionally represent a previously undescribed myofascial trigger point. Implications The suggested mechanism of ulnar sided hand pain represents a miniature chronic constriction injury similar to the animal model of neuropathic pain and may have relevance for regional pain elsewhere in the body.

Background and aims The evidence for interventional treatment of thoracic facet joint pain remains limited. This is partly due to inconsistency of the path of thoracic medial branches and a lower incidence of thoracic facet pain among spine pain patients. The purpose of this study is to evaluate the efficacy of bipolar radiofrequency (RF) neurotomy of medial branches for treating chronic thoracic facet joint pain. Methods This is a retrospective record review of all patients diagnosed to have thoracic facet pain with diagnostic block and subsequently treated with bipolar RF neurotomy of medial branch between January 2012 and December 2015. The outcome measures were mean changes in Numeral Rating Scale (NRS) and Pain Disability Index (PDI). Results There were 71 patients with complete data available for analysis. The mean age of the patients was 57.9±11.2 years. The mean duration of pain was 23±10.5 months. The majority of patients (82%) had pain reduction of more than 50% at 12 months after bipolar RF neurotomy. The NRS decreased significantly from baseline of 7.75±1.25 to 2.86±1.53 at 3 months and 2.82±1.29 at 12 months post-procedure ( p <0.001. p <0.001, respectively). The PDI improved significantly from 40.92±12.22 to 24.15±9.79, p <0.05). There were no serious adverse effects or complications of the procedure reported in this study. Conclusions Bipolar RF neurotomy of thoracic medial branch is associated with a significant reduction in thoracic facet joint pain. The promising findings from this case series merit further assessment with prospective, randomized controlled trial which will produce a more reliable and accurate finding for its clinical applications.