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Sample records for multimodal experimental pain

  1. [Multimodal pain therapy].

    PubMed

    Böger, A

    2014-06-01

    Chronic pain has both high prevalence and a significant economic impact in Germany. The most common chronic pain types are low back pain and headache. On the one hand, the management of chronic pain patients is incomplete, yet it is often overtreated in orthopaedic surgical settings with interventional procedures. The reason for this is the structure of outpatient management and the way it is paid for in Germany. Pain management of patients with private insurance cover is no better because of "doctor shopping". Medical guidelines could be of some help in improving the situation, but they are widely unknown, and have still to demonstrate whether they have any impact on GP treatment pathways. The "gold standard" multimodal pain therapy shows significant improvement in many studies compared to monomodal therapy regimes and interventional regimes, but is too rarely recommended by the patients' physicians, whether GPs or specialists. Because of the huge number of institutions nowadays that, for the sake of form, offer such multimodal therapies, these need to be differentiated in terms of their structural and process quality. A first step is the "k edoq" project. It is essential to improve knowledge of the principles of modern pain management. This includes better networking and communication between doctors, physiotherapists and psychologists, and at the grassroots level, providing the public with more detailed and better information.

  2. Multimodal pain stimulation of the gastrointestinal tract

    PubMed Central

    Drewes, Asbjørn Mohr; Gregersen, Hans

    2006-01-01

    Understanding and characterization of pain and other sensory symptoms are among the most important issues in the diagnosis and assessment of patient with gastrointestinal disorders. Methods to evoke and assess experimental pain have recently developed into a new area with the possibility for multimodal stimulation (e.g., electrical, mechanical, thermal and chemical stimulation) of different nerves and pain pathways in the human gut. Such methods mimic to a high degree the pain experienced in the clinic. Multimodal pain methods have increased our basic understanding of different peripheral receptors in the gut in health and disease. Together with advanced muscle analysis, the methods have increased our understanding of receptors sensitive to mechanical, chemical and temperature stimuli in diseases, such as systemic sclerosis and diabetes. The methods can also be used to unravel central pain mechanisms, such as those involved in allodynia, hyperalgesia and referred pain. Abnormalities in central pain mechanisms are often seen in patients with chronic gut pain and hence methods relying on multimodal pain stimulation may help to understand the symptoms in these patients. Sex differences have been observed in several diseases of the gut, and differences in central pain processing between males and females have been hypothesized using multimodal pain stimulations. Finally, multimodal methods have recently been used to gain more insight into the effect of drugs against pain in the GI tract. Hence, the multimodal methods undoubtedly represents a major step forward in the future characterization and treatment of patients with various diseases of the gut. PMID:16688791

  3. Multimodal pain management and arthrofibrosis.

    PubMed

    Lavernia, Carlos; Cardona, Diego; Rossi, Mark D; Lee, David

    2008-09-01

    Pain control after arthroplasty has been a key concern for orthopedic surgeons. After total knee arthroplasty (TKA), a small group of patients developed a painful joint with suboptimal range of motion. Manipulation under anesthesia increases flexion and extension while decreasing pain in most cases. The objective of the present investigation is to asses the effect of a multimodal pain management protocol on arthrofibrosis in primary TKAs. A cohort of 1136 patients who underwent primary TKA was selected. Patients were divided into 2 groups: group A had 778 procedures performed using a traditional approach to pain control; group B included 358 procedures that received multimodal pain management. Group A had an incidence of manipulation of 4.75% (37/778). Of 357 patients, 8 required manipulation in group B, which is an incidence of 2.24%. We recommend that orthopedic surgeons consider using a multimodal pain management protocol for TKA.

  4. Multimodal Treatment of Chronic Pain.

    PubMed

    Dale, Rebecca; Stacey, Brett

    2016-01-01

    Most patients with chronic pain receive multimodal treatment. There is scant literature to guide us, but when approaching combination pharmacotherapy, the practitioner and patient must weigh the benefits with the side effects; many medications have modest effect yet carry significant side effects that can be additive. Chronic pain often leads to depression, anxiety, and deconditioning, which are targets for treatment. Structured interdisciplinary programs are beneficial but costly. Interventions have their place in the treatment of chronic pain and should be a part of a multidisciplinary treatment plan. Further research is needed to validate many common combination treatments. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. [Multimodal pain therapy. Current situation].

    PubMed

    Kaiser, U; Sabatowski, R; Azad, S C

    2015-10-01

    A multidisciplinary approach for the management of patients with chronic pain is now well-established in many countries, especially in situations involving a complex disease process in the sense of a biopsychosocial model. Both the efficacy and cost-effectiveness of multidisciplinary pain treatment programs and their superiority compared to unimodal therapy has been documented in a number of studies, reviews and meta-analyses, in particular for patients suffering from chronic low back pain. Nevertheless, there are still major shortcomings concerning the definition of multimodal and multidisciplinary treatment and the quality of structures and processes, compared for example to the standards defined by the German Pain Society (Deutsche Schmerzgesellschaft). Furthermore, there is still no consensus on specific therapeutic approaches, the differentiation between responders and non-responders as well as on the tools required for measurement. All these questions will have to be answered by concerted efforts in a multicenter setting.

  6. Multimodal treatment of pain.

    PubMed

    Mathews, Manu

    2014-10-01

    Chronic pain is a complex disorder with extensive overlap in sensory and limbic pathways. It needs systemic therapy in addition to focused local treatment. This article discusses treatment modalities other than surgical and interventional approaches and also discusses the literature regarding these treatment modalities, including pharmacotherapy, physical and occupational therapy, psychological approaches including cognitive behavior therapy, and other adjunctive treatments like yoga and tai chi. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. [Multimodal pain therapy: principles and indications].

    PubMed

    Arnold, B; Brinkschmidt, T; Casser, H-R; Gralow, I; Irnich, D; Klimczyk, K; Müller, G; Nagel, B; Pfingsten, M; Schiltenwolf, M; Sittl, R; Söllner, W

    2009-04-01

    Multimodal pain therapy describes an integrated multidisciplinary treatment in small groups with a closely coordinated therapeutical approach. Somatic and psychotherapeutic procedures cooperate with physical and psychological training programs. For chronic pain syndromes with complex somatic, psychological and social consequences, a therapeutic intensity of at least 100 hours is recommended. Under these conditions multimodal pain therapy has proven to be more effective than other kinds of treatment. If monodisciplinary and/or outpatient therapies fail, health insurance holders have a legitimate claim to this form of therapy.Medical indications are given for patients with chronic pain syndromes, but also if there is an elevated risk of chronic pain in the early stadium of the disease and aiming at delaying the process of chronification. Relative contraindications are a lack of motivation for behavioural change, severe mental disorders or psychopathologies and addiction problems. The availability of multimodal pain treatment centers in Germany is currently insufficient.

  8. Association between Gene Polymorphisms and Pain Sensitivity Assessed in a Multi-Modal Multi-Tissue Human Experimental Model - An Explorative Study.

    PubMed

    Nielsen, Lecia Møller; Olesen, Anne Estrup; Sato, Hiroe; Christrup, Lona Louring; Drewes, Asbjørn Mohr

    2016-10-01

    The genetic influence on sensitivity to noxious stimuli (pain sensitivity) remains controversial and needs further investigation. In the present study, the possible influence of polymorphisms in three opioid receptor (OPRM, OPRD and OPRK) genes and the catechol-O-methyltransferase (COMT) gene on pain sensitivity in healthy participants was investigated. Catechol-O-methyltransferase has an indirect effect on the mu opioid receptor by changing its activity through an altered endogenous ligand effect. Blood samples for genetic analysis were withdrawn in a multi-modal and multi-tissue experimental pain model in 40 healthy participants aged 20-65. Seventeen different single nucleotide polymorphisms in different genes (OPRM, OPRK, OPRD and COMT) were included in the analysis. Experimental pain tests included thermal skin stimulation, mechanical muscle and bone stimulation and mechanical, electrical and thermal visceral stimulations. A cold pressor test was also conducted. DNA was available from 38 of 40 participants. Compared to non-carriers of the COMT rs4680A allele, carriers reported higher bone pressure pain tolerance threshold (i.e. less pain) by up to 23.8% (p < 0.015). Additionally, carriers of the C allele (CC/CT) of OPRK rs6473799 reported a 30.4% higher mechanical visceral pain tolerance threshold than non-carriers (TT; p < 0.019). For the other polymorphisms and stimulations, no associations were found (all p > 0.05). In conclusion, COMT rs4680 and OPRK rs6473799 polymorphisms seem to be associated with pain sensitivity. Thus, the findings support a possible genetic influence on pain sensitivity. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  9. Gender differences in outcomes of a multimodal pain management program.

    PubMed

    Pieh, Christoph; Altmeppen, Jürgen; Neumeier, Susanne; Loew, Thomas; Angerer, Michael; Lahmann, Claas

    2012-01-01

    Although gender differences in pain and analgesia are well known, it still remains unclear whether men and women vary in response to multimodal pain treatment. This study was conducted to investigate whether men and women exhibited different outcomes after an intensive multimodal pain treatment program. The daily outpatient program consisted of individual treatment as well as group therapy, with a total amount of therapy of 117.5h per patient. Overall, 496 patients (254 women) completed the multimodal program. Pretreatment parameters for pain, disability due to pain, pain duration, and pain chronicity stage, as well as age or psychiatric comorbidities, did not differ between genders. The average pain, measured with a Numeric Rating Scale, decreased after treatment of -1.54 (±1.96) with a large effect size (ES) of .911 for the total sample. However, there were considerable differences in the benefit for women (-1.83±2.12; ES 1.045) compared with men (-1.23±1.74; ES .758). Consistently, women (ES .694) improved more in pain-related disabilities in daily life than men (ES .436). These distinctions are not due to differences in pain duration, received medication, psychiatric comorbidities, pain chronicity stage, or application for a disability pension. Therefore, gender differences not only refer to chronic pain prevalence, pain perception, or experimental pain measurement, but also seem to have a clinically relevant impact on the response to pain therapy. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  10. [Multimodal therapy programs for chronic pain].

    PubMed

    Kopf, A; Gjoni, E

    2015-02-01

    Chronic pain is a common and disabling disorder with major consequences for patient quality of life and it is also a major economic burden to society. The management of chronic pain comprises a large range of different intervention strategies including pharmacological therapy, non-medicinal and invasive therapeutic options. While non-pharmacological and multimodal options are underused, monomodal options, especially pharmacotherapy and invasive therapies are overused. The effectiveness of multidisciplinary and multimodal treatment programs including physical and rehabilitation interventions and psychological treatment has been extensively studied in the last two decades. Evidence from randomized controlled trials demonstrates that there is low quality evidence for the effectiveness of exercise therapy alone, there is some evidence for the effectiveness of behavioral therapy and there is at least moderate evidence for the effectiveness of multidisciplinary and multimodal treatment and other active treatment reducing pain and increasing functional capacity at short and intermediate term. Therefore, blanket coverage with provision of adequate treatment programs for chronic pain as well as studies evaluating the best composition of treatment elements are needed. The characteristics of chronic pain, the necessary assessment procedures and treatment types are described.

  11. Multimodal MRI of experimental stroke

    PubMed Central

    Duong, Timothy Q

    2014-01-01

    Stroke is the fourth leading cause of death and the leading cause of long-term disability in the United States. Brain imaging data from experimental stroke models and stroke patients have shown that there is often a gradual progression of potentially reversible ischemic injury toward infarction. Reestablishing tissue perfusion and/or treating with neuroprotective drugs in a timely fashion are expected to salvage some ischemic tissues. Diffusion-weighted imaging based on magnetic resonance imaging (MRI) in which contrast is based on water motion can detect ischemic injury within minutes after onsets, whereas computed tomography and other imaging modalities fail to detect stroke injury for at least a few hours. Along with quantitative perfusion imaging, the perfusion-diffusion mismatch which approximates the ischemic penumbra could be imaged non-invasively. This review describes recent progresses in the development and application of multimodal MRI and image analysis techniques to study ischemic tissue at risk in experimental stroke in rats. PMID:24323751

  12. Do pain characteristics guide selection for multimodal pain rehabilitation?

    PubMed

    Enthoven, Paul; Molander, Peter; Öberg, Birgitta; Stålnacke, Britt-Marie; Stenberg, Gunilla; Gerdle, Björn

    2017-01-31

    To determine whether self-reported pain measures are associated with selection for multimodal or multidisciplinary rehabilitation (MMR) and whether this selection is influenced by sex. Cross-sectional cohort study. A total of 1,226 women and 464 men with chronic pain conditions from 2 university hospitals. Drawing from the Swedish Quality Registry for Pain Rehabilitation (SQRP), data on pain, psychological symptoms, function, health, and activity/participation were collected. Multiple logistic regression was used to investigate association of pain measures with selection for MMR (no/yes) after multidisciplinary assessment. Covariates were: age, educational level, anxiety, depression, working status, and several pain measures. High pain intensity in the previous week (odds ratio (OR) 0.92; 95% confidence interval (CI) 0.86-0.99) and high pain severity (Multidimensional Pain Inventory) (OR 0.83; 95% CI 0.74-0.95) were negatively associated with selection for MMR, whereas higher number of pain quadrants was positively associated with selection for MMR. Similar results were obtained for women, but none of the measures was predictive for men. This practice-based study showed that higher scores on self-reported pain were not associated with selection for MMR, and in women there was a negative association for higher pain intensity and pain severity. Thus, other factors than pain determine whether patients are selected for MMR.

  13. Multimodal nociceptive mechanisms underlying chronic pelvic pain

    PubMed Central

    HELLMAN, Kevin M.; PATANWALA, Insiyyah Y.; POZOLO, Kristen E.; TU, Frank F.

    2015-01-01

    Objective To evaluate candidate mechanisms underlying the pelvic floor dysfunction in women with chronic pelvic pain and/or painful bladder syndrome/interstitial cystitis. Notably, prior studies have not consistently controlled for potential confounding by psychological or anatomical factors. Study Design As part of a larger study on pelvic floor pain dysfunction and bladder pain sensitivity, we compared a measure of mechanical pain sensitivity, pressure pain thresholds, between women with pelvic pain and pain-free controls. We also assessed a novel pain measure using degree and duration of post-exam pain aftersensation, and conducted structural and functional assessments of the pelvic floor to account for any potential confounding. Phenotypic specificity of pelvic floor measures was assessed with receiver-operator characteristic curves adjusted for prevalence. Results A total of 23 women with chronic pelvic pain, 23 painful bladder syndrome, and 42 pain-free controls completed the study. Women with chronic pelvic pain or painful bladder syndrome exhibited enhanced pain sensitivity with lower pressure pain thresholds (1.18 [interquartile range: 0.87–1.41] kg/cm2) than pain-free participants (1.48 [1.11–1.76] kg/cm2; p<0.001) and prolonged pain aftersensation (3.5 [0–9] vs 0 [0–1] minutes; p< 0.001). Although genital hiatus (p<0.01) was wider in women with chronic pelvic pain there were no consistently observed group differences in pelvic floor anatomy, muscle tone or strength. The combination of pressure pain thresholds and aftersensation duration correlated with severity of pelvic floor tenderness (R2 =41–51, p’s< 0.01). Even after adjustment for prevalence, the combined metrics discriminated pain-free controls from women with chronic pelvic pain or painful bladder syndrome (area under the curve=0.87). Conclusion Both experimental assessment of pelvic floor pain thresholds and measurement of sustained pain are independently associated with pelvic pain

  14. Multimodal pediatric pain management (part 2).

    PubMed

    Friedrichsdorf, Stefan J

    2017-01-20

    Dr Stefan Friedrichsdorf speaks to Commissioning Editor Jade Parker: Stefan Friedrichsdorf, MD, is medical director of the Department of Pain Medicine, Palliative Care and Integrative Medicine at Children's Hospitals and Clinics of Minnesota in Minneapolis/St Paul, MN, USA, home to one of the largest and most comprehensive programs of its kind in the country. The pain and palliative care program is devoted to control acute, chronic/complex and procedural pain for inpatients and outpatients in close collaboration with all pediatric subspecialties at Children's Minnesota. The team also provides holistic, interdisciplinary care for children and teens with life limiting or terminal diseases and their families. Integrative medicine provides and teaches integrative, nonpharmacological therapies (such as massage, acupuncture/acupressure, biofeedback, aromatherapy and self-hypnosis) to provide care that promotes optimal health and supports the highest level of functioning in all individual children's activities. In this second part of the interview they discuss multimodal (opioid-sparing) analgesia for hospitalized children in pain and how analgesics and adjuvant medications, interventions, rehabilitation, psychological and integrative therapies act synergistically for more effective pediatric pain control with fewer side effects than a single analgesic or modality.

  15. Multimodal intrathecal analgesia in refractory cancer pain.

    PubMed

    Mastenbroek, Thierry C; Kramp-Hendriks, Bianca J; Kallewaard, Jan Willem; Vonk, Johanna M

    2017-01-01

    Cancer pain treatment has improved over the last decades. The majority of this population can be treated effectively with analgesics following the Guidelines of the original World Health Organisation (WHO). Unfortunately 10-15% of these patients still suffer from severe and refractory cancer pain, especially in the terminal phases of disease and require additional pain management modalities. Therefore, end-stage clinical interventions are particularly needed to minimize the perception of pain. With intrathecal therapy (ITT), drugs are delivered close to their site of action in the central nervous system avoiding first-pass metabolism and blood-brain barrier. It may improve analgesia with a smaller dose and possibly achieve a reduction in systemic or cerebral side effects compared to oral supplied medication alone. Multimodal analgesia enables further dose reduction with improved analgesia and fewer side effects. In this retrospective research we investigated the effectiveness and side-effect profile of intrathecal morphine, bupivacaine and clonidine. Patients were followed until death occurred. Pain scores and side effects were recorded before initiating ITT (T0), just after initiating ITT (T1), at hospital discharge (T2), in the ambulant setting (T3) and the last obtained scores before death occurred (T4). Nine patients were included who suffered from severe and refractory cancer pain, not reacting to conventional pain management or had intolerable side effects. Primary tumour location was pancreatic (4), urothelial (3) and prostate (2). Primary pain was considered neuropathic or mixed neuropathic-nociceptive. The treatment team consisted of an anaesthetist, specialized nurse in coordination with primary physician, treating oncologist and specialized home care. All patients were free of pain after initiation of the intrathecal therapy. The average follow-up period was 11 weeks in which there was a slight increase in NRS-score. In the last days before death

  16. Pain Management in Pregnancy: Multimodal Approaches

    PubMed Central

    Shah, Shalini; Banh, Esther T.; Koury, Katharine; Bhatia, Gaurav; Nandi, Roneeta; Gulur, Padma

    2015-01-01

    Nonobstetrical causes of pain during pregnancy are very common and can be incapacitating if not treated appropriately. Recent reports in the literature show that a significant percentage of pregnant women are treated with opioids during pregnancy. To address common pain conditions that present during pregnancy and the available pharmacological and nonpharmacological treatment options, for each of the pain conditions identified, a search using MEDLINE, PubMed, Embase, and Cochrane databases was performed. The quality of the evidence was evaluated in the context of study design. This paper is a narrative summary of the results obtained from individual reviews. There were significant disparities in the studies in terms of design, research and methodology, and outcomes analyzed. There is reasonable evidence available for pharmacological approaches; however, these are also associated with adverse events. Evidence for nonpharmacological approaches is limited and hence their efficacy is unclear, although they do appear to be primarily safe. A multimodal approach using a combination of nonpharmacological and pharmacological options to treat these pain conditions is likely to have the most benefit while limiting risk. Research trials with sound methodology and analysis of outcome data are needed. PMID:26448875

  17. Multimodal Distribution of Human Cold Pain Thresholds

    PubMed Central

    Lötsch, Jörn; Dimova, Violeta; Lieb, Isabel; Zimmermann, Michael; Oertel, Bruno G.; Ultsch, Alfred

    2015-01-01

    Background It is assumed that different pain phenotypes are based on varying molecular pathomechanisms. Distinct ion channels seem to be associated with the perception of cold pain, in particular TRPM8 and TRPA1 have been highlighted previously. The present study analyzed the distribution of cold pain thresholds with focus at describing the multimodality based on the hypothesis that it reflects a contribution of distinct ion channels. Methods Cold pain thresholds (CPT) were available from 329 healthy volunteers (aged 18 – 37 years; 159 men) enrolled in previous studies. The distribution of the pooled and log-transformed threshold data was described using a kernel density estimation (Pareto Density Estimation (PDE)) and subsequently, the log data was modeled as a mixture of Gaussian distributions using the expectation maximization (EM) algorithm to optimize the fit. Results CPTs were clearly multi-modally distributed. Fitting a Gaussian Mixture Model (GMM) to the log-transformed threshold data revealed that the best fit is obtained when applying a three-model distribution pattern. The modes of the identified three Gaussian distributions, retransformed from the log domain to the mean stimulation temperatures at which the subjects had indicated pain thresholds, were obtained at 23.7 °C, 13.2 °C and 1.5 °C for Gaussian #1, #2 and #3, respectively. Conclusions The localization of the first and second Gaussians was interpreted as reflecting the contribution of two different cold sensors. From the calculated localization of the modes of the first two Gaussians, the hypothesis of an involvement of TRPM8, sensing temperatures from 25 – 24 °C, and TRPA1, sensing cold from 17 °C can be derived. In that case, subjects belonging to either Gaussian would possess a dominance of the one or the other receptor at the skin area where the cold stimuli had been applied. The findings therefore support a suitability of complex analytical approaches to detect mechanistically

  18. [Multimodal pain therapy in Germany: structure and quality].

    PubMed

    Casser, Hans-Raimund; Nagel, Bernd

    2016-01-01

    Multimodal Pain Management is a comprehensive treatment of complex chronic pain syndromes. In addition to medical therapy various other specialized therapeutical interventions based on the biopsychosocial model of pain origin and chronic pain development are added.Medical indications are given for patients with chronic pain syndromes, but also if there is an elevated risk of chronic pain in the early stadium of the disease and aiming at delaying the process of chronification. Multimodal pain management has been included in the official catalogue of the recognized medical procedure for day clinic units as well as for inpatients pain management. As there is still a lack of clarity and of consistency about the implementation of multimodal pain management the ad-hoc-Kommission on multimodal interdisciplinary pain management of the German Pain Society has proposed a position paper that has been worked out in a multilevel and interdisciplinary consensus process. Moreover a basic tool for documentation and quality management of pain therapy was developed by the German Pain Society (KEDOQ-Schmerz) as the data basis for nationwide, cross-sectional and independent scientific research in health services in Germany. In future KEDOQ-Schmerz will also used as a method for external quality management in chronic pain therapy in Germany. © Georg Thieme Verlag Stuttgart · New York.

  19. Effectiveness of a multimodal treatment program for somatoform pain disorder.

    PubMed

    Pieh, Christoph; Neumeier, Susanne; Loew, Thomas; Altmeppen, Jürgen; Angerer, Michael; Busch, Volker; Lahmann, Claas

    2014-03-01

    Chronic pain conditions are highly prevalent, with somatoform pain disorder accounting for a large proportion. However, the psychological forms of treatment currently used achieve only small to medium effect sizes. This retrospective study investigated the effectiveness of a 5-week multimodal pain program for patients with somatoform pain disorder. The diagnosis of somatoform pain disorder was confirmed by a specialist for anesthesiology and pain management and a specialist for psychosomatic medicine. Therapy outcome was evaluated with a Numeric Rating Scale (NRS), the Pain Disability Index (PDI), and the Pain Perception Scale. Within the study sample (n = 100), all parameters showed a significant and clinically relevant improvement at the end of therapy (P values < 0.001). The highest effect sizes (d) were found for reduction in average pain rating (NRS: d = 1.00) and the affective items of the Pain Perception Scale (SES-A: d = 0.07). The lowest effect sizes were found for improvement of pain-related disabilities (PDI: d = 0.42) and sensory items of the Pain Perception Scale (SES-S: d = 0.50). Despite high chronification of pain condition, with average pain duration of greater than 8 years, the multimodal treatment program showed medium to large effect sizes on the outcome of patients with somatoform pain disorder. Compared with previous data with small to moderate effect sizes, a multimodal program seems to be more effective than other interventions to address somatoform pain disorder. © 2013 World Institute of Pain.

  20. Multimodal Analgesia for Acute Postoperative and Trauma-Related Pain.

    PubMed

    Polomano, Rosemary C; Fillman, Mechele; Giordano, Nicholas A; Vallerand, April Hazard; Nicely, Kelly L Wiltse; Jungquist, Carla R

    2017-03-01

    : Multimodal analgesia, which combines analgesic drugs from different classes and employs analgesic techniques that target different mechanisms of pain, is recommended in the treatment of acute postoperative and trauma-related pain because its synergistic effect maximizes pain relief at lower analgesic doses, thereby reducing the risk of adverse drug effects. Using a case-based approach, this article reviews various multimodal analgesic therapies used in the treatment of acute pain; discusses their benefits; and summarizes findings from related research, recommendations from evidence-based practice guidelines, and expert consensus reports.

  1. Experimental verification of MMI by singlemode-multimode-singlemode and multimode-singlemode structures

    NASA Astrophysics Data System (ADS)

    Majumder, Saikat; Ghosh, Amarnath; Roy, Bapita; Chakraborty, Rajib

    2015-06-01

    Multimode Interference (MMI) based on self imaging phenomenon is investigated using matrix approach. Experimentally MMI is verified using singlemode-multimode-singlemode and multimodesinglemode structures of optical fiber. The results obtained are also verified by BPM technique.

  2. Determining Pain Detection and Tolerance Thresholds Using an Integrated, Multi-Modal Pain Task Battery

    PubMed Central

    Hay, Justin L.; Okkerse, Pieter; van Amerongen, Guido; Groeneveld, Geert Jan

    2016-01-01

    Human pain models are useful in the assessing the analgesic effect of drugs, providing information about a drug's pharmacology and identify potentially suitable therapeutic populations. The need to use a comprehensive battery of pain models is highlighted by studies whereby only a single pain model, thought to relate to the clinical situation, demonstrates lack of efficacy. No single experimental model can mimic the complex nature of clinical pain. The integrated, multi-modal pain task battery presented here encompasses the electrical stimulation task, pressure stimulation task, cold pressor task, the UVB inflammatory model which includes a thermal task and a paradigm for inhibitory conditioned pain modulation. These human pain models have been tested for predicative validity and reliability both in their own right and in combination, and can be used repeatedly, quickly, in short succession, with minimum burden for the subject and with a modest quantity of equipment. This allows a drug to be fully characterized and profiled for analgesic effect which is especially useful for drugs with a novel or untested mechanism of action. PMID:27166581

  3. Determining Pain Detection and Tolerance Thresholds Using an Integrated, Multi-Modal Pain Task Battery.

    PubMed

    Hay, Justin L; Okkerse, Pieter; van Amerongen, Guido; Groeneveld, Geert Jan

    2016-04-14

    Human pain models are useful in the assessing the analgesic effect of drugs, providing information about a drug's pharmacology and identify potentially suitable therapeutic populations. The need to use a comprehensive battery of pain models is highlighted by studies whereby only a single pain model, thought to relate to the clinical situation, demonstrates lack of efficacy. No single experimental model can mimic the complex nature of clinical pain. The integrated, multi-modal pain task battery presented here encompasses the electrical stimulation task, pressure stimulation task, cold pressor task, the UVB inflammatory model which includes a thermal task and a paradigm for inhibitory conditioned pain modulation. These human pain models have been tested for predicative validity and reliability both in their own right and in combination, and can be used repeatedly, quickly, in short succession, with minimum burden for the subject and with a modest quantity of equipment. This allows a drug to be fully characterized and profiled for analgesic effect which is especially useful for drugs with a novel or untested mechanism of action.

  4. Multimodal Analgesia, Current Concepts, and Acute Pain Considerations.

    PubMed

    Helander, Erik M; Menard, Bethany L; Harmon, Chris M; Homra, Ben K; Allain, Alexander V; Bordelon, Gregory J; Wyche, Melville Q; Padnos, Ira W; Lavrova, Anna; Kaye, Alan D

    2017-01-01

    Management of acute pain following surgery using a multimodal approach is recommended by the American Society of Anesthesiologists whenever possible. In addition to opioids, drugs with differing mechanisms of actions target pain pathways resulting in additive and/or synergistic effects. Some of these agents include alpha 2 agonists, NMDA receptor antagonists, gabapentinoids, dexamethasone, NSAIDs, acetaminophen, and duloxetine. Alpha 2 agonists have been shown to have opioid-sparing effects, but can cause hypotension and bradycardia and must be taken into consideration when administered. Acetaminophen is commonly used in a multimodal approach, with recent evidence lacking for the use of IV over oral formulations in patients able to take medications by mouth. Studies involving gabapentinoids have been mixed with some showing benefit; however, future large randomized controlled trials are needed. Ketamine is known to have powerful analgesic effects and, when combined with magnesium and other agents, may have a synergistic effect. Dexamethasone reduces postoperative nausea and vomiting and has been demonstrated to be an effective adjunct in multimodal analgesia. The serotonin-norepinephrine reuptake inhibitor, duloxetine, is a novel agent, but studies are limited and further evidence is needed. Overall, a multimodal analgesic approach should be used when treating postoperative pain, as it can potentially reduce side effects and provide the benefit of treating pain through different cellular pathways.

  5. Multimodal analgesia for perioperative pain in three cats.

    PubMed

    Steagall, Paulo V M; Monteiro-Steagall, Beatriz P

    2013-08-01

    Adequate pain relief is usually achieved with the simultaneous use of two or more different classes of analgesics, often called multimodal analgesia. The purpose of this article is to highlight the use of perioperative multimodal analgesia and the need to individualize the treatment plan based on the presenting condition, and to adjust it based on the response to analgesia for a given patient. This case series presents the alleviation of acute pain in three cats undergoing different major surgical procedures. These cases involved the administration of different classes of analgesic drugs, including opioids, non-steroidal anti-inflammatory drugs, tramadol, ketamine, gabapentin and local anesthetics. The rationale for the administration of analgesic drugs is discussed herein. Each case presented a particular challenge owing to the different cause, severity, duration and location of pain. Pain management is a challenging, but essential, component of feline practice: multimodal analgesia may minimize stress while controlling acute perioperative pain. Individual response to therapy is a key component of pain relief in cats.

  6. Comparison of Two Multimodal Pain Regimens Used for Postoperative Pain Control in Total Joint Arthroplasty Patients.

    PubMed

    Jinnah, Alexander H; Smith, Beth P; Perricelli, Brett C

    Postoperative pain control following total joint arthroplasty results in improved patient mobilization, participation in physical therapy, and potentially reduced hospital costs. It was hypothesized that using a multimodal pain protocol focusing on periarticular injections including liposomal bupivacaine would have improved results when compared with a parenteral opioid-based regimen. The results showed a decrease in length of stay and rate of discharge to skilled nursing facilities with the implementation of a novel multimodal pain protocol. Furthermore, there was no change in patient satisfaction before and after the execution of the new protocol. It was concluded that using a multimodal pain protocol based on periarticular injections can lead to decreased length of stay and a decrease in transfer to skilled nursing facilities without a change in patient satisfaction.

  7. [Multimodal pain therapy - implementation of process management - an attempt to consider management approaches].

    PubMed

    Dunkel, Marion; Kramp, Melanie

    2012-07-01

    The combination of medical and economical proceedings allows new perspectives in the illustration of medical workflows. Considering structural and developmental aspects multimodal therapy programs show similarities with typical subjects of economic process systems. By pointing out the strategic appearance of the multimodal pain therapy concept multimodal approaches can be described to some extent by using management approaches. E. g., an economic process landscape can be used to represent procedures of a multimodal pain therapy program. © Georg Thieme Verlag Stuttgart · New York.

  8. Effectiveness of multimodal pain management protocol in total knee arthroplasty patients.

    PubMed

    Lewis, Cynthia; Gunta, Kathleen; Mitchell, Kimberly; Bobay, Kathleen

    2012-01-01

    Numerous methods for postoperative pain management after total knee arthroplasty (TKA) are reported. Multimodal pain management approaches, including peripheral nerve blocks and systemic analgesia, have been shown to decrease patient pain, increase patient satisfaction with pain control, decrease length of stay (LOS), and improve patient outcomes. To compare patient outcomes (pain scores, LOS, postoperative nausea and vomiting, and movement) between 66 TKA patients of a single orthopaedic surgeon in 2010 who received a multimodal approach to 45 historical (control) patients in 2009 who did not receive a multimodal pain management protocol. Patients who were treated with the multimodal pain protocol had significantly lower pain scores in the immediate postoperative period, less postoperative nausea and vomiting day of surgery, and a decrease in LOS by half a day despite increased buckling and increased level of assistance with ambulation. The multimodal pain approach improved patient outcomes in TKA patients.

  9. Multimodal pain management and the future of a personalized medicine approach to pain.

    PubMed

    Manworren, Renee C B

    2015-03-01

    In the soon-to-be-released clinical practice guidelines from the American Pain Society, multimodal analgesia is recommended for pain management after all surgical procedures. Multimodal analgesia is a surgery-specific population-based approach to optimize pain relief by treating pain through multiple mechanisms along multiple sites of the nociceptive pathway. The reliance on multiple medications and therapies inherent to the multimodal approach also may address individual patient differences in analgesic pharmacogenetics (ie, the influence of allelic differences in single genes and the associated variability in specific medication responses). Perioperative nurses may see a shift from surgery-specific population-based multimodal analgesic protocols to a personalized medicine approach as knowledge of the genetic influences of analgesic metabolism and pain sensitivity is translated into clinical practice. Personalized medicine is proposed as an individualized pain management treatment plan that eventually may be based on each patient's genetic coding for metabolism of analgesics and pain sensitivity. Copyright © 2015 AORN, Inc. Published by Elsevier Inc. All rights reserved.

  10. A Multimodal Approach for Myofascial Pain Syndrome: A Prospective Study.

    PubMed

    Segura-Pérez, María; Hernández-Criado, M Teresa; Calvo-Lobo, César; Vega-Piris, Lorena; Fernández-Martín, Raquel; Rodríguez-Sanz, David

    The purpose of this study was to analyze pain intensity in patients with myofascial pain syndrome (MPS) following a multimodal rehabilitation protocol. A prospective study was carried out following the Template for Intervention Description and Replication criteria. Patients were recruited from the rehabilitation unit of a university hospital in Spain between 2009 and 2013. Patients were included if they had a medical diagnosis of MPS in any of the following regions: cervicobrachial (n = 102), lumbosacral (n = 30), elbow (n = 14), ankle and foot (n = 10), and temporomandibular jaw (n = 1). The multimodal rehabilitation protocol included myofascial trigger point dry needling, spray and stretching, Kinesio taping, eccentric exercise, and patient education. The protocol was applied for 4 weeks (5 sessions) for the active and/or latent myofascial trigger points in each body region. Pain intensity was measured by using the visual analog scale (VAS) immediately before beginning of the study and 1 week after completion of the protocol. The study sample comprised 150 patients (mean ± standard deviation age, 51.5 ± 1.19 years). Statistically significant differences were obtained for reduction in pain intensity (4 ± 2.03; P = .002). Clinically relevant reductions (VAS ≥30 mm; P < .001) were obtained in 78.7% of the interventions. Four treatment sessions reduced the VAS score by 10 mm in 83.55% of the sample. There were no statistically significant differences (P = .064) for reduction in pain intensity in the different body regions. A multimodal rehabilitation protocol showed clinically relevant differences in the reduction in pain intensity in different body regions in patients with MPS. Copyright © 2017. Published by Elsevier Inc.

  11. [Structure and process quality of multimodal pain therapy. Results of a survey of pain therapy clinics].

    PubMed

    Nagel, B; Pfingsten, M; Brinkschmidt, T; Casser, H-R; Gralow, I; Irnich, D; Klimczyk, K; Sabatowski, R; Schiltenwolf, M; Sittl, R; Söllner, W; Arnold, B

    2012-12-01

    Multimodal therapy has demonstrated good clinical effectiveness in the treatment of chronic pain syndromes. However, within the German health system a comprehensive and nationwide access to multimodal therapy is not available and further improvement is therefore necessary. In order to analyze the current status of multimodal therapy and specifically its structural and procedural requirements and qualities, a survey was carried out in 37 pain clinics with established multimodal treatment programs. An anonymous questionnaire was used for data collection. Results demonstrated that a substantial accordance was found between all pain clinics concerning requirements for space, facilities and staff. Structured multidisciplinary assessments were carried out by all pain clinics even though the amount of time allocated for this varied widely. The main focus of multimodal therapy in all facilities was based on a common philosophy with a cognitive-behavioral approach to reduce patient helplessness and avoidance behavior and to increase physical and psychosocial activities as well as to strengthen self-efficacy. Some differences in the ways and means to achieve these goals could be demonstrated in the various programs.

  12. [Long-term efficacy of multimodal pain therapy for chronic back pain].

    PubMed

    Zhuk, A; Schiltenwolf, M; Neubauer, E

    2017-08-22

    The day clinic for pain therapy at the Orthopedic Clinic of the University Heidelberg has been in existence since 2001. In the context of multimodal pain therapy patients with chronic and chronically recurring pain of the musculoskeletal system are treated. The present prospective long-term study investigated the effects of therapy using the following outcome parameters: pain intensity, disability, depression, functional capacity and vitality. For this purpose patients with low back pain (n = 59) were questioned in writing at four measurement times: start of therapy (t0), completion of therapy (t1), 6 months (t2) and 10 years (t3) following therapy. Of the examined patients 78% were in chronification stages I and II, according to the Mainz pain staging system (MPSS) of Gerbershagen. The main aim of the study was to examine the effects of multimodal pain therapy in the long term. In the short, medium and long term significant differences were found in the outcome parameters with low to high effect sizes (d = 0.36-1.85). There was a continuous improvement of the pain intensity in the long term, and 10 years after pain therapy the effect size for the currently asked pain intensity was d = 1.28. Multimodal pain therapy is an effective method for the treatment of chronic back pain. It not only leads to short and medium-term improvements but also proves to be efficient in the long term. This form of pain therapy seems to lead to long-term success, particularly for patients with low-grade chronification.

  13. Fewer postoperative fevers: an unexpected benefit of multimodal pain management?

    PubMed

    Karam, Joseph A; Zmistowski, Benjamin; Restrepo, Camilo; Hozack, William J; Parvizi, Javad

    2014-05-01

    Elevated temperatures after total joint arthroplasty (TJA) are common and can be a source of anxiety both for the patient and the surgical team. Although such fevers rarely are caused by acute infection, many patients are subjected to extensive testing for elevated body temperature after surgery. We recently implemented a multimodal pain management regimen for TJA, which includes acetaminophen, pregabalin, and celecoxib or toradol, and because some of these medications have antipyrexic properties, it was speculated that this protocol might influence the frequency of postoperative pyrexia. The purpose of this study was to determine whether patients treated under this protocol were less likely to exhibit postoperative fever after primary TJA, compared with a historical control group, and whether they were less likely to receive postoperative testing as part of a fever workup. We compared 1484 primary TJAs in which pain was controlled primarily with opioid-based relief from July 2004 to December 2006 with 2417 procedures from July 2009 to December 2011 during which time multimodal agents were used. The same three surgeons were responsible for care in both of these cohorts. Oral temperature readings in the first 5 postoperative days (POD) were drawn from a review of medical records, which also were evaluated for fever workup tests, including urinalysis, urine culture, chest radiograph, and blood culture. Fever was defined by the presence of a temperature measurement over 38.5 °C. Patients having preoperative fever or postoperative fever starting later than POD 5 were excluded. Before surgery, there were no differences between the groups' temperature measurements. Fewer patients developed fever in the multimodal analgesia group than in the control group (5% versus 25%, p < 0.001). Furthermore, fewer patients underwent workup for fever in the multimodal analgesia cohort (1.8% of patients undergoing 155 individual tests) compared with the control cohort (9.8% of

  14. [Multimodal pain therapy for treatment of chronic pain syndrome. Consensus paper of the ad hoc commission on multimodal interdisciplinary pain management of the German Pain Society on treatment contents].

    PubMed

    Arnold, B; Brinkschmidt, T; Casser, H-R; Diezemann, A; Gralow, I; Irnich, D; Kaiser, U; Klasen, B; Klimczyk, K; Lutz, J; Nagel, B; Pfingsten, M; Sabatowski, R; Schesser, R; Schiltenwolf, M; Seeger, D; Söllner, W

    2014-10-01

    Multimodal pain management is a comprehensive treatment of complex chronic pain syndromes. In addition to medical therapy various other specialized therapeutic interventions based on the biopsychosocial model of pain origin and chronic pain development, are added. During the last few years treatment centers for chronic pain have been established throughout Germany. Multimodal pain management has been included in the official catalogue of the recognized medical procedures for day clinic units as well as for inpatient pain management. In daily practice there is, however, still a lack of clarity and of consistency about the components that multimodal pain management should contain. This is the reason for the ad hoc commission on multimodal interdisciplinary pain management of the German Pain Society to propose the following position paper that has been worked out in a multilevel and interdisciplinary consensus process. The paper describes the mandatory treatment measures in the four core disciplines of multimodal pain management, pain medicine, psychotherapy, exercise therapy including physiotherapy and assistant medical professions including nurses.

  15. [Evaluation of a multimodal pain therapy at the University Pain Centre Dresden].

    PubMed

    Schütze, A; Kaiser, U; Ettrich, U; Grosse, K; Gossrau, G; Schiller, M; Pöhlmann, K; Brannasch, K; Scharnagel, R; Sabatowski, R

    2009-12-01

    Data of a multimodal pain management program of the multidisciplinary pain management centre at the University Hospital of Dresden is presented. Over a period of 4 weeks, supplemented by an additional week 3 months later (booster week), patients with chronic pain of different origins are being treated in groups of 12. Based on the principles of the biopsychosocial pain model and the idea of functional restoration, the program is dedicated for pain patients where outpatient treatment was insufficient. The program was evaluated on the basis of pain intensity (NRS), pain disability (PDI), fear and depression (HADS-D), catastrophizing (CSQ) and health-related quality of life and vitality (SF-36). The data were collected at the beginning and end of the initial 4 week treatment period, at the end of the booster period as well as 6 and 12 months after the end of active treatment. A total of 189 patients were included in the program in the period from January 2006 until August 2008. All outcome parameter showed statistically significant improvements with small to high effect sizes (ES 0.20-0.95). The results stayed stable even 1 year after the treatment. The highest effect sizes were found in catastrophizing (ES 0.86) and average pain intensity (ES 0.95). The primary pain diagnosis (e. g. low back pain versus headache) had no impact on treatment outcome. Significant and clinically relevant improvements could be achieved with the multimodal pain management program in groups of 12 patients. The results were stable over a time period of 1 year. Pain diagnosis had no impact on the outcome.

  16. Does pain severity guide selection to multimodal pain rehabilitation across gender?

    PubMed

    Haukenes, I; Hensing, G; Stålnacke, B M; Hammarström, A

    2015-07-01

    Studies have addressed the effect of multimodal pain rehabilitation (MMR), whereas criteria for selection are sparse. This study examines whether higher scores on musculoskeletal pain measures are associated with selection to MMR, and whether this differs across gender. A clinical population of 262 male and 589 female patients was recruited consecutively during 3 years, 2007-2010. The patients were referred from primary care to a pain rehabilitation clinic in Northern Sweden for assessment and selection to MMR. Register-based data on self-reported pain were linked to patients' records where outcome (MMR or not) was stated. We modelled odds ratios for selection to MMR by higher scores on validated pain measures (pain severity, interference with daily life, pain sites and localized pain vs. varying pain location). Covariates were age, educational level and multiple pain measures. Anxiety and depression (Hospital, Anxiety and Depression Scale) and working status were used in sensitivity tests. Higher scores of self-reported pain were not associated with selection to MMR in multivariate models. Among women, higher scores on pain severity, pain sites and varying pain location (localized pain = reference) were negatively associated with selection to MMR. After adjustment for multiple pain measures, the negative odds ratio for varying location persisted (OR = 0.59, 95% CI = 0.39-0.89). Higher scores on self-reported pain did not guide selection to MMR and a negative trend was found among women. Studies of referral patterns and decision processes may contribute to a better understanding of the clinical practice that decides selection to MMR. © 2014 European Pain Federation - EFIC®

  17. Acute Pain Service and multimodal therapy for postsurgical pain control: evaluation of protocol efficacy.

    PubMed

    Moizo, E; Berti, M; Marchetti, C; Deni, F; Albertin, A; Muzzolon, F; Antonino, A

    2004-11-01

    The institution of a postoperative Acute Pain Control Service is mandatory to improve the control of pain induced by surgical injury. Treatment of postoperative pain may be achieved using a combination of analgesic agents and techniques, reducing the incidence of side effects owing to the lower doses of the individual drugs. In 1997 we established an Acute Pain Service (APS) at the San Raffaele Hospital in Milan. The aim of this study was to assess the efficacy and safety of our APS both in terms of treatment protocols and organisational issues. In this prospective observational study we included 592 patients undergoing abdominal, gynecological, or orthopedic surgery with severe expected pain. According to general guidelines on pain treatment, the patients were assigned to different treatment protocols based on the kind of operation. All protocols were based on the multimodal therapy, with the association of nonsteroidal anti-inflammatory drugs (NSAIDS), opioids and regional anesthesia techniques. During the first 48 h of the postoperative period we recorded vital signs, level of pain and occurrence of any side effect. Our analgesic protocols proved to be effective and safe (low incidence of side effects) for every surgery. The incidence of postoperative nausea and vomiting was higher in patients receiving patient-controlled morphine than that with continuous epidural or nerve block. After lower abdominal surgery, pain at movement at 24 h was significantly lower in the epidural group than in the Patient Control Analgesia group. Nausea and vomiting, numbness and paresthesias at the lower limbs were higher in gynecological patients. A larger percentage of orthopedic patients in the epidural group reported numbness and paresthesias at the lower limbs in comparison with patients receiving continuous peripheral nerve block. In agreement with previous literature, this study confirmed that a multimodal approach to pain treatment provides an adequate control of

  18. Towards multimodal nonlinear optical tomography - experimental methodology

    NASA Astrophysics Data System (ADS)

    Vogler, N.; Medyukhina, A.; Latka, I.; Kemper, S.; Böhm, M.; Dietzek, B.; Popp, J.

    2011-08-01

    All-optical microspectroscopic and tomographic tools reveal great potential for clinical dermatologic diagnostics, i.e., investigation of human skin and skin diseases. While optical-coherence tomography has been complemented by two-photon fluorescence tomography and second-harmonic generation tomography, a joint study of various nonlinear optical microspectroscopies, i.e., application of the recently developed multimodal imaging approach, to sizable human-tissue samples has not been evaluated up to now. Here, we present such multimodal approach combining different nonlinear optical contrast mechanisms for imaging, namely two-photon excited fluorescence (TPF), second-harmonic generation (SHG), and coherent anti-Stokes Raman scattering (CARS) into a joint microscopic experiment. We show the potential of imaging large skin areas and discuss the information obtained in a case study comparing normal skin and keloid tissue.

  19. [Multidisciplinary assessment for multimodal pain therapy. Indications and range of performance].

    PubMed

    Casser, H-R; Arnold, B; Brinkschmidt, T; Gralow, I; Irnich, D; Klimczyk, K; Nagel, B; Pfingsten, M; Sabatowski R; Schiltenwolf, M; Sittl, R; Söllner, W

    2013-08-01

    According to evidence-based German national guidelines for non-specific low back pain, a broad multidisciplinary assessment is indicated after persisting pain experience of 6 weeks in order to check the indications for an multi- and interdisciplinary pain therapy program. In this paper the necessary topics, the content and the disciplines involved as well as the extent of the multidisciplinary assessment are described as developed by the ad hoc commission on multimodal pain therapy of the German Pain Society.

  20. Multimodal pain management in total knee arthroplasty: a prospective randomized controlled trial.

    PubMed

    Lamplot, Joseph D; Wagner, Eric R; Manning, David W

    2014-02-01

    We analyze the effects of a multimodal analgesic regimen on postoperative pain, function, adverse effects and satisfaction compared to patient-controlled analgesia (PCA). Thirty-six patients undergoing TKA were randomized to receive either (1) periarticular injection before wound closure (30cc 0.5% bupivacaine, 10mg MSO4, 15 mg ketorolac) and multimodal analgesics (oxycodone, tramadol, ketorolac; narcotics as needed) or (2) hydromorphone PCA. Preoperative and postoperative data were collected for VAS pain scores, time to physical therapy milestones, hospital stay length, patient satisfaction, narcotic consumption and medication-related adverse effects. The multimodal group had lower VAS scores, fewer adverse effects, lower narcotic usage, higher satisfaction scores and earlier times to physical therapy milestones. Multimodal pain management protocol decreases narcotic usage, improves pain scores, increases satisfaction and enhances early recovery. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Experimental human pain models in gastro-esophageal reflux disease and unexplained chest pain

    PubMed Central

    Drewes, Asbjørn Mohr; Arendt-Nielsen, Lars; Funch-Jensen, Peter; Gregersen, Hans

    2006-01-01

    Methods related to experimental human pain research aim at activating different nociceptors, evoke pain from different organs and activate specific pathways and mechanisms. The different possibilities for using mechanical, electrical, thermal and chemical methods in visceral pain research are discussed with emphasis of combinations (e.g., the multimodal approach). The methods have been used widely in assessment of pain mechanisms in the esophagus and have contributed to our understanding of the symptoms reported in these patients. Hence abnormal activation and plastic changes of central pain pathways seem to play a major role in the symptoms in some patients with gastro-esophageal reflux disease and in patients with functional chest pain of esophageal origin. These findings may lead to an alternative approach for treatment in patients that does not respond to conventional medical or surgical therapy. PMID:16718803

  2. Intranasal ketorolac as part of a multimodal approach to postoperative pain.

    PubMed

    Pergolizzi, Joseph V; Taylor, Robert; Raffa, Robert B

    2015-04-01

    Despite recent advances in the knowledge of pain mechanisms and pain management, postoperative pain continues to be a problem. Inadequately managed postsurgical pain has both clinical and economic consequences such as longer recovery times, delayed ambulation, higher incidence of complications, increased length of hospital stay, and potential to develop into chronic pain. Generally, opioids are the mainstay option for pain management in patients with moderate-to-severe postsurgical pain; however, opioids have significant side effects and have abuse potential. To improve patient and economic outcomes after surgery, postoperative pain guidelines have suggested incorporating a multi-modal/multi-mechanistic approach to pain treatment. A multi-modal approach is the simultaneous use of a combination of two or more (usually opioid and non-opioid) analgesics that provide two different mechanisms of actions. Utilizing a multi-modal approach may result in a greater reduction in pain vs. single therapies in addition to minimizing opioid use, thus reducing opioid related side effects. However, not all approaches may be effective for all types of patients and not all analgesics may be a viable option for outpatient settings, ambulatory surgery, or the fast-track surgical procedures. In this report, we present a review of the literature with a focus on intranasal ketorolac in order to provide a timely update regarding past, present, and future multi-modal treatment options for postoperative pain. © 2014 World Institute of Pain.

  3. Best evidence in multimodal pain management in spine surgery and means of assessing postoperative pain and functional outcomes.

    PubMed

    Devin, Clinton J; McGirt, Matthew J

    2015-06-01

    Multimodal approaches to pain management have arisen with the goal of improving postoperative pain and reducing opioid analgesic use. We performed a comprehensive literature review to determine grades of recommendation for commonly used agents in multimodal pain management and provide a best practice guideline. To evaluate common drugs used in multimodal treatment of pain, a search was performed on English language publications on Medline (PubMed; National Library of Medicine, Bethesda, MD, USA). Manuscripts were rated as Level I-V according to the North American Spine Society's (NASS) standardized levels of evidence tables. Grades of recommendation were assigned for each drug based on the NASS Clinical Guidelines for Multidisciplinary Spine Care. There is good (Grade A) evidence gabapentinoids, acetaminophen, neuraxial blockade and extended-release local anesthetics reduce postoperative pain and narcotic requirements. There is fair (Grade B) evidence that preemptive analgesia and nonsteroidal anti-inflammatory drugs (NSAID) result in reduced postoperative pain. There is insufficient and/or conflicting (Grade I) evidence that muscle relaxants and ketamine provide a significant reduction in postoperative pain or narcotic usage. There is fair (Grade B) evidence that short-term use of NSAID result in no long-term reduction in bone healing or fusion rates. Comprehensive assessment of the effectiveness of perioperative pain control can be accomplished through the use of validated measures. Multimodal pain management protocols have consistently been demonstrated to allow for improved pain control with less reliance on opioids. There is good quality evidence that supports many of the common agents utilized in multimodal therapy, however, there is a lack of evidence regarding optimal postoperative protocols or pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Benefits of a Multimodal Regimen for Postsurgical Pain Management in Colorectal Surgery.

    PubMed

    Beck, David E; Margolin, David A; Babin, Sheena Farragut; Russo, Christine Theriot

    2015-01-01

    Postoperative pain management is a major concern and a significant component of postoperative care pathways for surgery patients. We performed a retrospective medical record review of 233 consecutive patients undergoing major colorectal surgery from October 2011 to January 2013 at an academic medical center. All patients were managed with similar enhanced recovery pathways; 66 patients received multimodal postsurgical pain management that included liposomal bupivacaine intraoperatively, and 167 patients received conventional pain management with intravenous opioids. Comparisons were made using t test and chi-square analysis with StatView (SAS Institute Inc.). Patients receiving multimodal pain management with liposomal bupivacaine injected in the surgical site at the end of major colorectal procedures had lower postoperative pain scores and used significantly less opioids at 12, 24, 36, 48, 60, and 72 hours (P=0.03). Patients in the multimodal group also had a significantly decreased risk of opioid-related adverse events, with decreased use of antipruritic medications and antiemetic medications postoperatively. A significant decrease in length of postoperative hospital stay was seen in the multimodal group (7.2 vs 9.0 days, P=0.04). The use of multimodal pain management including liposomal bupivacaine during major colorectal surgeries improved postoperative outcomes, decreased lengths of stay, and increased bed availability.

  5. Multimodal group rehabilitation compared to usual care for patients with chronic neck pain: a pilot study.

    PubMed

    Hudson, Julie Sarah; Ryan, Cormac Gerard

    2010-12-01

    The aim of this pilot randomised controlled trial (RCT) was to compare multimodal group rehabilitation to usual care physiotherapy for patients with chronic neck pain (CNP). Participants (n=14) were randomly assigned to one of two interventions, multimodal group rehabilitation or usual care physiotherapy. Multimodal group rehabilitation involved stability, strengthening and proprioceptive exercises along with an educational programme. Patients attended for 1h, once a week for six weeks. The usual care group was treated as deemed appropriate by their physiotherapist. A blinded assessor recorded baseline and post-intervention scores of disability and pain using the neck disability index (NDI) and the 0-10 pain numerical rating scale (NRS), respectively. One participant from each group dropped out before receiving any intervention. Post-intervention both groups significantly improved in both function and pain scores (p ≤ 0.01). The mean change in the NDI scores for the multimodal group versus the usual care group were 12.3 ± 5.3% and 7.4 ± 4.8%, and pain NRS score changes were 4.6 ± 2.3 and 4.5 ± 2.2, respectively. There was no significant difference in improvements in disability (p = 0.84) or pain (p = 0.67) between groups. These results warrant further investigation of multimodal group rehabilitation for CNP, and provide data to inform an appropriately powered full-scale RCT with long-term follow-up. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Past Pain Experience and Experimentally induced Pain Perception.

    PubMed

    Paquet, Aude; Plansont, Brigitte; Labrunie, Anaïs; Malauzat, Dominique; Girard, Murielle

    2017-08-02

    Many intercurrent factors may be involved in the modulation of the pain message and its expression, such as the previous experience of pain built along the life. In this study, we aimed to determine whether susceptibility to experimentally induced pain is differentially influenced by the individual previous painful experience in subjects with schizophrenia (SC) major depression (MD), and controls (C). The SC (30), MD (32) and C (30) groups participated in experimental pain tests (application of pressure and induction of ischemia) after a semi-structured interview to make an inventory of the previous painful experiences, and the evaluation of anxiety either with autonomic (heart rate, blood pressure) or psychological (Hospital Anxiety Depression scale HAD) measures, and catastrophism. The reported pain intensities, severities, duration, of the previous pain events, and the number of previous painful events were equivalent in the three groups, except for the number of painful events experimented before the last six months which was lower in the MD group. Experimental pain sensitivity was influenced by the diagnosis, the HAD scores or the number and intensities of previous lived painful events. The lack of a past experience of pain was comparable for the different groups, suggesting that psychiatric disorders do not affect the experience of pain associated with daily life or past events. For each subject, the reported previous experience of pain influences the present feeling of pain.

  7. [The multimodal interdisciplinary therapeutic program in chronic back pain. A new treatment strategy].

    PubMed

    Casser, H; Riedel, T; Schrembs, C; Ingenhorst, A; Kühnau, D

    1999-11-01

    The epidemic-like rise in chronic low back pain in western industrial nations is less an expression of a medical than a psychosocial phenomenon. Differentiation between acute, chronic or chronifying pain is of crucial importance for therapeutic procedures. Pain syndromes in the muscular-skeletal system tend to become chronic to a far larger extent than expected. More than 80 % of low back pain represents a functional pain syndrome and does not show any pathoanatomical correlate. Pain existing independently seems to be predestined by a somatic and psychosocial deconditioning syndrome. Those at risk of chronifying pain or those whose pain is already chronic should be given an interdisciplinary, multimodal therapeutic program. A pilot study was carried out in our clinic: multidisciplinary treatment was given to our patients (of which over 90 % belonged to stages II and III on the Gerbershagen scale) and the result was significant improvement in the measurements of pain intensity, sensoric and affective pain perception, their list of complaints, the common scale of depression and the pain disability index. Taking previously published studies into consideration, it is safe to say that a multidisciplinary, multimodal program of therapy even after stay in hospital results in considerable relief of pain and improvement in the ability to cope with the pain for patients with chronified pain syndromes in the muscular-skeletal system which are resistant to treatment on an outpatient basis.

  8. New therapeutic strategy for chronifying back pain. The multimodal, interdisciplinary therapeutic program.

    PubMed

    Casser, H-R; Riedel, T; Schrembs, C; Ingenhorst, A; Kühnau, D

    1999-11-01

    The epidemic-like rise in chronic low back pain in western industrial nations is less an expression of a medical than a psychosocial phenomenon. Differentiation between acute, chronic or chronifying pain is of crucial importance for therapeutic procedures. Pain syndromes in the muscular-skeletal system tend to become chronic to a far larger extent than expected. More than 80 % of low back pain represents a functional pain syndrome and does not show any pathoanatomical correlate. Pain existing independently seems to be predestined by a somatic and psychosocial deconditioning syndrome. Those at risk of chronifying pain or those whose pain is already chronic should be given an interdisciplinary, multimodal therapeutic program. A pilot study was carried out in our clinic: multidisciplinary treatment was given to our patients (of which over 90 % belonged to stages II and III on the Gerbershagen scale) and the result was significant improvement in the measurements of pain intensity, sensoric and affective pain perception, their list of complaints, the common scale of depression and the pain disability index. Taking previously published studies into consideration, it is safe to say that a multidisciplinary, multimodal program of therapy even after stay in hospital results in considerable relief of pain and improvement in the ability to cope with the pain for patients with chronified pain syndromes in the muscular-skeletal system which are resistant to treatment on an outpatient basis.

  9. A systematic review of the outcomes reported in multimodal pain therapy for chronic pain.

    PubMed

    Deckert, S; Kaiser, U; Kopkow, C; Trautmann, F; Sabatowski, R; Schmitt, J

    2016-01-01

    There are no recommendations provided for the outcome domains of chronic pain that should be explicitly considered in each clinical trial to describe the efficacy and effectiveness of multimodal pain therapy (MPT). Our aims were to summarize all reported outcome domains in studies assessing the effects of MPT for chronic pain, and to subsequently inform a consensus-based development of a core outcome set of domains in this field. Medline, Embase and AMED were searched for studies reporting on chronic pain for at least 3 months that applied MPT and investigated outcome domains. All reported outcome domains were extracted from eligible articles. The patient-reported outcome measurement information system (PROMIS) was applied for conceptual classification. From 3626 potentially relevant titles, 70 studies were included. The median and maximal numbers of outcome domains were 8 and 34, respectively. Although most studies (n = 45/70) assessed a combination of all three core health areas, i.e. physical, mental and social health, there was great variation in the specific domains chosen to address these core health areas. No outcome domain was measured consistently in all studies. After selection of all outcome domains which were reported in at least 10% of all studies included, we identified 14 different outcome domains, mostly operationalized through the domains pain intensity (n = 56/70) and depressive symptoms (n = 42/70). The current lack of standardization of outcome domains in MPT studies hinders to readily compare interventions from different trials and is a barrier towards evidence-based decision making. Based on these results, the development of a core outcome set of domains for MPT has been initiated. © 2015 European Pain Federation - EFIC®

  10. Effectiveness of multimodal pain management after bipolar hemiarthroplasty for hip fracture: a randomized, controlled study.

    PubMed

    Kang, Hyun; Ha, Yong-Chan; Kim, Jin-Yun; Woo, Young-Cheol; Lee, Jae-Sung; Jang, Eui-Chan

    2013-02-20

    Appropriate pain management affects outcome after hip fracture surgery. Although multimodal pain management is commonly used for pain control for patients undergoing elective surgery, few studies have evaluated its use in those undergoing hip fracture surgery. This prospective randomized study was designed to determine the clinical value of multimodal pain management with preemptive pain medication and intraoperative periarticular multimodal drug injections in patients undergoing bipolar hip hemiarthroplasty. Of eighty-two cognitively intact elderly patients about to undergo bipolar hemiarthroplasty after a hip fracture, forty-three were randomly assigned to receive preemptive pain medication and intraoperative periarticular injections (Group I) and thirty-nine were assigned to not receive preemptive medication and injections (Group II). These two groups were compared with regard to the pain level on postoperative days one, four, and seven; at discharge; and when they started walking and standing exercises. Total amounts of fentanyl used, the frequency of use of patient-controlled analgesia, patient satisfaction at discharge, and perioperative complications were recorded. Group I had a lower pain level than Group II on postoperative days one and four, but no intergroup difference in pain level was observed on postoperative day seven. The total amount of fentanyl used and the frequency of use of patient-controlled analgesia were also lower in Group I. Patient satisfaction at discharge was higher in Group I. No significant intergroup differences were found in the times until the patients walked or performed standing exercises or in the complications. Multimodal pain management provides additional pain relief until the fourth postoperative day, improves patient satisfaction at discharge, and reduces total narcotic consumption for postoperative pain management after hip hemiarthroplasty for hip fractures.

  11. Post-traumatic stress in patients with injury-related chronic pain participating in a multimodal pain rehabilitation program

    PubMed Central

    Stålnacke, Britt-Marie; Östman, Anna

    2010-01-01

    Aim: To investigate post-traumatic stress, pain intensity, depression, and anxiety in patients with injury-related chronic pain before and after participating in multimodal pain rehabilitation. Methods: Twenty-eight patients, 21 women and seven men, who participated in the multimodal rehabilitation programs (special whiplash program for whiplash injuries within 1.5 years after the trauma or ordinary program) answered a set of questionnaires to assess post-traumatic stress (Impact of Event Scale [IES], pain intensity [Visual Analogue Scale (VAS)], depression, and anxiety (Hospital Anxiety and Depression Scale [HAD] before and after the programs. Results: Both pain intensity and post-traumatic stress decreased significantly after the rehabilitation programs in comparison with before (VAS: 57.8 ± 21.6 vs. 67.5 ± 21.9; P = 0.009, IES total score 21.8 ± 13.2 vs. 29.5 ± 12.9; P < 0.001). Patients younger than 40 years reported a statistically higher level of post-traumatic stress compared with patients older than 40 years both before (P = 0.037) and after rehabilitation (P = 0.023). No statistically significant differences were found on the HAD scores. Conclusion: The multimodal rehabilitation programs were effective in reducing both pain intensity and post-traumatic stress. The experience of higher levels of post-traumatic stress in younger persons has to be taken into account when managing patients with injury-related chronic pain. PMID:20361062

  12. [Acute inpatient multimodal pain therapy and rehabilitation: Framework conditions, tasks and differentiated patient allocation].

    PubMed

    Arnold, B; Casser, H-R; Klimczyk, K; Lutz, J; Brinkschmidt, T; Gralow, I; Irnich, D; Kaiser, U; Nagel, B; Schiltenwolf, M; Pfingsten, M; Sabatowski, R; Söllner, W

    2015-12-01

    Multimodal pain treatment programs are widely accepted as the medical treatment standard in the management of patients with chronic pain syndromes. The concepts and treatment strategies are based on the biopsychosocial model of pain and programs for early restoration of function. Although this concept is primarily implemented in the curative field, i.e. in hospitals for the treatment of patients with chronic pain diseases, modified programs based on the International Classification of Functioning (ICF) can now also be found in rehabilitation clinics. Despite the assumed similarities, significant differences in, for example the aims of the therapy and relevant structural and process variables have to be kept in mind when allocating patients to a program as provided by a hospital or a rehabilitation clinic. The aim of this article is to present the framework structures of both treatment levels with respect to the implementation of multimodal pain therapy programs and to elucidate the differential diagnostic approach to the indications.

  13. A multimodal approach for postoperative pain management after lumbar decompression surgery: a prospective, randomized study.

    PubMed

    Garcia, Ryan Michael; Cassinelli, Ezequiel H; Messerschmitt, Patrick J; Furey, Christopher G; Bohlman, Henry H

    2013-08-01

    A prospective and randomized study. The objective of this study was to assess the efficacy of a novel multimodal analgesic regimen in reducing postoperative pain and intravenous morphine requirements after primary multilevel lumbar decompression surgery. The use of opioid medications after surgery can lead to incomplete analgesia and may cause undesired side effects such as respiratory depression, somnolence, urinary retention, and nausea. Multimodal (opioid and nonopioid combination) analgesia may be an effective alternative to morphine administration leading to improved postoperative analgesia with diminished side effects. After Institutional Review Board approval, 22 patients who underwent a primary multilevel lumbar decompression procedure were randomly assigned to receive either only intravenous morphine or a multimodal (celecoxib, pregabalin, extended release oxycodone) analgesic regimen. Postoperatively, all patients were allowed to receive intravenous morphine on an as needed basis. Intravenous morphine requirements were then recorded immediately postoperative, at 6, 12, 24 hours, and the total requirement before discharge. Patient postoperative pain levels were determined using the visual analog pain scale and were documented at 0, 4, 8, 12, 16, 24, and 36 hours postoperative. There were no significant differences in available patient demographics, intraoperative blood loss, or postoperative hemovac drain output between study groups. Total postoperative intravenous morphine requirements in addition to morphine requirements at all predetermined time points were less in patients randomized to receive the multimodal analgesic regimen. Visual analog pain scores were lower at all postoperative time points in patients randomized to receive the multimodal analgesic regimen. Time to solid food was significantly less in the multimodal group. There were no major identifiable postoperative complications in either treatment group. Opioid and nonopioid analgesic

  14. The Effects of a Multimodal Rehabilitation Program on Symptoms and Ground-Reaction Forces in Runners With Patellofemoral Pain Syndrome.

    PubMed

    Esculier, Jean-Francois; Bouyer, Laurent J; Roy, Jean-Sébastien

    2016-02-01

    Patellofemoral pain (PFP) is one of the most frequent running-related injuries. However, few interventions taking into consideration the specificity of running have been shown to be effective in runners with PFP. To evaluate the effects of a multimodal rehabilitation program including lower-limb-strengthening/ motor-control exercises, advice on running biomechanics, and symptoms management on symptoms, strength, and ground-reaction forces in runners with PFP. Pre- to post- quasi-experimental. Gait-analysis laboratory and private physical therapy clinic. 21 runners with PFP (34.1 ± 6.0 y old, symptoms duration 38.1 ± 45.5 mo). An 8-wk multimodal rehabilitation program including lower-limb- and core-strengthening and motor-control exercises, as well as advice on running gait and symptoms management. The Activities of Daily Living Scale of the Knee Outcome Survey (KOS-ADLS) questionnaire and visual analog scales for usual pain (VAS-U), worst pain (VAS-W), and pain during running (VAS-R) were used to assess changes in symptoms and function. Vertical ground-reaction forces (VGRF) during running and lower-limb isometric strength were also measured. Statistically and clinically significant improvements (P < .001) were reported on KOS-ADLS (+17.8 pts), VAS-U (-19.2 pts), VAS-W (-28.7 pts), and VAS-R (-32.2 pts) after the intervention. No significant changes in isometric strength were observed. The instantaneous vertical loading rate was decreased after the intervention (P = .002), and this reduction was correlated with changes in KOS-ADLS scores (P = .028). This multimodal intervention was successful in reducing pain and improving function of runners with PFP. However, no significant changes in lower-limb strength were observed. It appears that changes in VGRF combined with appropriate training advice could explain the clinical outcomes.

  15. Multimodal approach to postoperative pain control in patients undergoing rotator cuff repair.

    PubMed

    Cho, Chul-Hyun; Song, Kwang-Soon; Min, Byung-Woo; Lee, Kyung-Jae; Ha, Eunyoung; Lee, Yong-Chul; Lee, Young-Kuk

    2011-10-01

    This prospective study was undertaken to compare the effectiveness and safety of a multimodal pain control protocol with those of intravenous patient-controlled analgesia in rotator cuff repair. Seventy patients scheduled for rotator cuff repair were randomized to either a multimodal pain control group (group 1, 40 patients) or an intravenous patient-controlled analgesia group (group 2, 30 patients). We compared these two groups with respect to level of pain before surgery to the fifth postoperative day, duration of postoperative rehabilitation, consumption of additional analgesics, and adverse effects. Mean visual analogue scale scores immediately after surgery (day 0) and on postoperative days 1-5 were 6.9, 5.5, 4.3, 3.3, 3.0, and 2.6 in group 1 and 7.8, 5.9, 4.4, 4.7, 4.3, and 3.7 in group 2. Pain relief was significantly better in group 1 on days 0, 3, 4, and 5 (P = 0.026, 0.006, 0.010, and 0.009, respectively). Furthermore, functional recovery occurred earlier in group 1. No significant differences were observed between the two groups with respect to nausea, vomiting, urinary retention, and headache (n.s.), but group 1 was found to be significantly less likely to experience dizziness or urticaria (P = 0.007, 0.017, respectively). One other significant difference was observed: 1 patient (2.5%) in group 1 and 6 patients (20%) in group 2 discontinued regimen because of medication-related adverse effects (P = 0.016). The multimodal pain control protocol was found to offer more effective postoperative pain control with fewer adverse effects than intravenous patient-controlled analgesia. However, achieving adequate pain control within the first 48 h of surgery remains challenging, and thus, the developments of more effective and safer multimodal pain control protocols are required.

  16. Reliability of phantom pain relief in neurorehabilitation using a multimodal virtual reality system.

    PubMed

    Sano, Yuko; Ichinose, Akimichi; Wake, Naoki; Osumi, Michihiro; Sumitani, Masahiko; Kumagaya, Shin-Ichiro; Kuniyoshi, Yasuo

    2015-01-01

    The objective of this study is to demonstrate the reliability of relief from phantom limb pain in neurore-habilitation using a multimodal virtual reality system. We have developed a virtual reality rehabilitation system with multimodal sensory feedback and applied it to six patients with brachial plexus avulsion or arm amputation. In an experiment, patients executed a reaching task using a virtual phantom limb displayed in a three-dimensional computer graphic environment manipulated by their real intact limb. The intensity of the phantom limb pain was evaluated through a short-form McGill pain questionnaire. The experiments were conducted twice on different days at more than four-week intervals for each patient. The reliability of our task's ability to relieve pain was demonstrated by the test-retest method, which checks the degree of the relative similarity between the pain reduction rates in two experiments using Fisher's intraclass correlation coefficient (ICC). The ICC was 0.737, indicating sufficient reproducibility of our task. The average of the reduction rates across participants was 50.2%, and it was significantly different from 0 (p <; 0:001). Overall, our findings indicate that neurorehabilitation using our multimodal virtual reality system reduces the phantom limb pain with sufficient reliability.

  17. [Inpatient multimodal pain therapy : Additive value of neuromuscular core stability exercises for chronic back pain].

    PubMed

    Giesche, F; Streicher, H; Maiwald, M; Wagner, P

    2017-04-01

    The medical and healthcare economic burden caused by chronic lumbar back pain (CLBP) requires the use of interdisciplinary treatment approaches. The present study aimed to evaluate whether the effectiveness of inpatient multimodal pain therapy (MPT, operations and procedures (OPS) coding 8-918.02), can be increased by implementing additional neuromuscular core stability exercises (NCSE). As part of a prospective controlled study, subjects with CLBP (n = 48, 17 males, 58.2 ± 11.7 years) were allocated to one of two groups. One group received standard care (SC, n =23) encompassing manual, pharmacological and psychological therapy in addition to passive physiotherapeutic applications. The intervention group (IG, n =25) additionally completed NCSE. On the day of admission and on discharge as well as 1 and 6 weeks after inpatient care, pain intensity (numeric rating scale), pain-related routine daily functions (Oswestry disability index), well-being (SF-12 Health Survey) and motor function parameters (trunk strength, endurance and postural control) were assessed. Data analysis was performed using statistical inference methods. In addition, effect sizes (Cohen's d) of intergroup differences were calculated. Both groups showed significant reductions in pain intensity (p < 0.05, d > 0.6) at all measurement points (MP). Physical well-being and disability (p < 0.05, d > 0.6) were improved 1 week after discharge in the intervention group only. Overall, no systematic differences between groups were detected (p > 0.05). In relation to the motor outcomes, no significant changes over time nor between groups were verified (p > 0.05). Despite the use of an additional NCSE, no significant added value in individuals with CLBP could be detected, although a systematic pre-post effect in daily functions and physical well-being (one week after discharge) was observed for the IG only. Therefore, on the basis of the study results, the implementation of additional NCSE into

  18. Experimental pain phenotyping in community-dwelling individuals with knee osteoarthritis.

    PubMed

    Cardoso, Josue S; Riley, Joseph L; Glover, Toni; Sibille, Kimberly T; Bartley, Emily J; Goodin, Burel R; Bulls, Hailey W; Herbert, Matthew; Addison, Adriana S; Staud, Roland; Redden, David T; Bradley, Laurence A; Fillingim, Roger B; Cruz-Almeida, Yenisel

    2016-09-01

    Pain among individuals with knee osteoarthritis (OA) is associated with significant disability in older adults, and recent evidence demonstrates enhanced experimental pain sensitivity. Although previous research showed considerable heterogeneity in the OA clinical pain presentation, less is known regarding the variability in responses to experimental pain. The present study included individuals with knee OA (n = 292) who participated in the Understanding Pain and Limitations in Osteoarthritic Disease study and completed demographic and psychological questionnaires followed by a multimodal quantitative sensory testing (QST) session. Quantitative sensory testing measures were subjected to variable reduction procedures to derive pain sensitivity index scores, which in turn were entered into a cluster analysis. Five clusters were significantly different across all pain sensitivity index variables (P < 0.001) and were characterized by: (1) low pain sensitivity to pressure pain (N = 39); (2) average pain sensitivity across most modalities (N = 88); (3) high temporal summation of punctate pain (N = 38); (4) high cold pain sensitivity (N = 80); and (5) high sensitivity to heat pain and temporal summation of heat pain (N = 41). Clusters differed significantly by race, gender, somatic reactivity, and catastrophizing (P < 0.05). Our findings support the notion that there are distinct subgroups or phenotypes based on experimental pain sensitivity in community-dwelling older adults with knee OA, expanding previous findings of similar cluster characterizations in healthy adults. Future research is needed to further understand the pathophysiological mechanisms underlying pain within these subgroups, which may be of added value in tailoring effective treatments for people with OA.

  19. [Interdisciplinary pain assessment in the hospital setting : Merely a door-opener to multimodal pain therapy?

    PubMed

    Sens, E; Mothes-Lasch, M; Lutz, J F

    2017-07-17

    Chronic pain is characterized by a complex interaction of somatic, mental and social factors. Assessing these factors in patients with chronic pain is vital during the diagnostic work-up and when making a structured treatment plan. Interdisciplinary pain assessment (ISA) is the most promising method to deal with these challenges. This article presents our experience in performing pain assessments in the hospital setting and also illustrates the characteristic features of chronic pain patients undergoing such assessments. This study reviews and evaluates patient data from 2704 ISAs performed at the Interdisciplinary Pain Centre of the Zentralklinik Bad Berka, Germany, between 2008 and 2015. The majority of our ISA patients are severely handicapped and show distinct signs of chronic disease. A large proportion of patients is either unable to work or receiving benefits (invalidity pension or retirement pension). In addition, patients reported long disease durations and high emotional distress. Treatment recommendations were based on the patients' individual clinical presentations and examination results. More than half of the patients required multimodal pain management, while adjustments or therapeutic withdrawal of pain medications, in particular of opioids, were indicated in many patients. Our study shows that ISA enables fast, high-quality diagnostic assessments of chronic pain while taking the biopsychosocial model of pain in particular into account. In addition, ISA is not biased with regard to outcome results and recommends the further treatment that appears best for the individual patient. ISA leads not only to inpatient treatment, but also to treatment in other therapeutic settings and, as such, is not merely a door-opener to multimodal pain therapy.

  20. [Prevalence of mental disorders in multimodal therapy of chronic back pain].

    PubMed

    Artner, J; Lattig, F; Cakir, B; Gündel, H; Reichel, H; Spiekermann, J A

    2012-12-01

    Because of its biopsychosocial factors chronic back pain is often resistant to unimodal therapy regimes. Multimodal pain programs are a promising therapy option in the management of chronic pain as they focus on functional restoration. The aim of the study was to evaluate the prevalence of psychopathology in patients with chronic back pain. The study included 127 patients suffering from chronic back pain in multimodal inpatient pain therapy who were assessed by a psychologist. A retrospective analysis was performed focusing on the psychological diagnoses. Further factors investigated were age, gender, numeric rating scale (NRS) pain intensity at the beginning and end of the program, hospital anxiety and depression scale (HADS), further psychological treatment recommendations and migration background. Fisher's exact test was performed to calculate the significance in the different subgroups. The results showed that there was a high prevalence of depression, anxiety disorders and adjustment disorders in patients with chronic back pain. In this cohort the prevalence of depression and anxiety disorders was significantly higher than the estimated prevalence of the normal German population.

  1. Vicarious pain while observing another in pain: an experimental approach

    PubMed Central

    Vandenbroucke, S.; Crombez, G.; Van Ryckeghem, D. M. L.; Brass, M.; Van Damme, S.; Goubert, L.

    2013-01-01

    Objective: This study aimed at developing an experimental paradigm to assess vicarious pain experiences. We further explored the putative moderating role of observer's characteristics such as hypervigilance for pain and dispositional empathy. Methods: Two experiments are reported using a similar procedure. Undergraduate students were selected based upon whether they reported vicarious pain in daily life, and categorized into a pain responder group or a comparison group. Participants were presented a series of videos showing hands being pricked whilst receiving occasionally pricking (electrocutaneous) stimuli themselves. In congruent trials, pricking and visual stimuli were applied to the same spatial location. In incongruent trials, pricking and visual stimuli were in the opposite spatial location. Participants were required to report on which location they felt a pricking sensation. Of primary interest was the effect of viewing another in pain upon vicarious pain errors, i.e., the number of trials in which an illusionary sensation was reported. Furthermore, we explored the effect of individual differences in hypervigilance to pain, dispositional empathy and the rubber hand illusion (RHI) upon vicarious pain errors. Results: Results of both experiments indicated that the number of vicarious pain errors was overall low. In line with expectations, the number of vicarious pain errors was higher in the pain responder group than in the comparison group. Self-reported hypervigilance for pain lowered the probability of reporting vicarious pain errors in the pain responder group, but dispositional empathy and the RHI did not. Conclusion: Our paradigm allows measuring vicarious pain experiences in students. However, the prevalence of vicarious experiences of pain is low, and only a small percentage of participants display the phenomenon. It remains however unknown which variables affect its occurrence. PMID:23781187

  2. Multimodal Narcotic Limited Perioperative Pain Control With Colorectal Surgery

    ClinicalTrials.gov

    2017-03-16

    Colon Cancer; Colon Diverticulosis; Colonic Neoplasms; Colonic Diverticulitis; Pain, Postoperative; Ileus; Ileus Paralytic; Ileus; Mechanical; Constipation Drug Induced; Constipation; Rectum Cancer; Rectum Neoplasm

  3. Multimodal Management of Mechanical Neck Pain Using a Treatment Based Classification System

    PubMed Central

    Heintz, Megan M.; Hegedus, Eric J.

    2008-01-01

    The purpose of this case study was twofold: 1) to illustrate the use of a treatment-based classification (TBC) system to direct the early intervention of a patient with mechanical neck pain, and 2) to show the progression of this patient with multimodal-modal intervention. The patient exhibited axial neck pain with referral into her upper extremity. Her pain peripheralized with cervical range of motion and centralized with joint mobilization placing her primarily in the centralization category. Her poor posture and associated muscle weakness along with the chronicity of symptoms placed her secondarily into the exercise and conditioning group resulting in a multi-modal treatment as the patient progressed. Although the design of this case report prevents wide applicability, this study does illustrate the effective use of the TBC system for the cervical spine as captured by accepted outcomes measures. PMID:19771194

  4. Acute pain Factors predictive of post-operative pain and opioid requirement in multimodal analgesia following knee replacement.

    PubMed

    Thomazeau, J; Rouquette, A; Martinez, V; Rabuel, C; Prince, N; Laplanche, J L; Nizard, R; Bergmann, J F; Perrot, S; Lloret-Linares, C

    2016-05-01

    Despite the development of multimodal analgesia for postoperative pain management, opioids are still required for effective pain relief after knee arthroplasty. We aimed to identify the determinants of post-operative pain intensity and post-operative opioid requirement in this context. In this observational prospective study, we recorded patient characteristics, pre-operative pain intensity, anxiety and depression levels, sensitivity and pain thresholds in response to an electrical stimulus, and mu-opioid receptor (OPRM1) and catechol-O-methyltransferase (COMT) single-nucleotide polymorphisms. Multivariate linear regression models were used to identify predictors of post-operative pain at rest and opioid requirement. We included 109 patients. Pre-operative pain at rest (p = 0.047), anxiety level (p = 0.001) and neuropathic pain symptoms (p = 0.030) were independently and positively associated with mean post-operative pain intensity adjusted for mean post-operative morphine equivalent dose (MED). Mean post-operative pain intensity at rest was lower (p = 0.006) in patients receiving celecoxib and pregabalin in the post-operative period, with all other variables constant. Mean post-operative MED over 5 days was low, but highly variable (78.2 ± 32.1 mg, from 9.9 to 170 mg). Following adjustment for mean post-operative pain intensity, it was independently negatively correlated with age (p = 0.004), and positively correlated with associated paracetamol treatment (p = 0.031). No genetic effect was detected in our sample. Our findings suggest that clinicians could use the pre-operative pain profile, in terms of anxiety levels, neuropathic pain symptoms, and chronic pre-operative pain intensity, to improve the efficacy of pain management after knee surgery. © 2015 European Pain Federation - EFIC®

  5. Multi-Modal Treatment Approach to Painful Rib Syndrome: Case Series and Review of the Literature.

    PubMed

    Germanovich, Andrew; Ferrante, Francis Michael

    2016-03-01

    Mechanical chest wall pain is a common presenting complaint in the primary care office, emergency room, and specialty clinic. Diagnostic testing is often expensive due to similar presenting symptoms that may involve the heart or lungs. Since the chest wall biomechanics are poorly understood by many clinicians, few effective treatments are offered to patients with rib-related acute pain, which may lead to chronic pain. This case series and literature review illustrates biomechanics involved in the pathogenesis of rib-related chest wall pain and suggests an effective multi-modal treatment plan using interventional techniques with emphasis on manual manipulative techniques. Case series and literature review. Pain clinic in an academic medical center. This is a case series of 3 patients diagnosed with painful rib syndrome using osteopathic palpatory physical examination techniques. Ultrasound-guided intercostal nerve blocks were followed by manual manipulation of mechanically displaced ribs as a part of our multi-modal treatment plan. A review of the literature was undertaken to clarify nomenclature used in the description of rib-related pain, to describe the biomechanics involved in the pathogenesis of mechanical rib pain, and to illustrate the use of effective manual manipulation techniques. This review is introductory and not a complete review of all manual or interventional pain management techniques applicable to the treatment of mechanical rib-related pain. Manual diagnostic and therapeutic skills can be learned by physicians to treat biomechanically complex rib-related chest wall pain in combination with interventional image-guided techniques. Pain physicians should learn certain basic manual manipulation skills both for diagnostic and therapeutic purposes.

  6. Anxiety measures during induced experimental pain.

    PubMed

    Coulthard, P; Rood, J P

    1993-01-01

    Results of analgesic studies obtained using experimental pain are often not comparable with those obtained from clinical studies. This may be because anxiety, which plays an important role in the pain experience, may not be evoked by experimentally induced pain. The aim of this study is to measure the level of anxiety induced by the submaximum effort tourniquet technique, which produces pain similar in quality to clinical pain. The mean time that subjects tolerated the pain from the tourniquet was 14.94 minutes. Systolic blood pressure and heart rate increased. Visual analogue scale measures of anxiety showed an overall increase during the experiment but were highly erratic individually. This study suggests that the submaximum effort tourniquet technique is incapable of inducing the same type of anxiety experienced with clinical pain.

  7. Obesity effect on a multimodal physiotherapy program for low back pain suffers: patient reported outcome

    PubMed Central

    2013-01-01

    Background Several studies have linked obesity to the increased likelihood of lower back pain, but there are no studies focussing on the effectiveness of a multimodal physiotherapy programme (MPP) in obese subjects who suffer from chronic non-specific lower back pain (CNLBP). The aim of this study was to compare the effectiveness of an MPP in obese (G1) (body mass index (BMI):≥30) and non-obese (G2) (BMI:<30) patients with CNLBP. Methods A quasi-experimental study with pre- and post-intervention evaluations of an MPP (lasting 8 weeks) was conducted on obese and non-obese patients with CNLBP. A total of 53 people were included in the study: G1, composed of 19 patients (10 men and 9 women) with a BMI of 33.75 and a mean age of 52.94 years, and G2, composed of 34 patients (18 men and 16 women) with a mean age of 49.19 years and an average BMI of 25.56. All patients were measured to calculate pre-intervention (baseline) and post-intervention (8 weeks) changes in disability (RMQ) and health related quality of life in physical and mental health component state of SF12 and quality of life (EQ-5D and EQ-VAS). Results Post-intervention, non-obese group shown significant high improve than obese group in disability (RMQ: 4.00), physical component state of SF-12: (-7.26) and quality of life (EQ-VAS.: -10.49). Conclusions In patients with CNLBP, a BMI more than or equal to 30 minimises the effects of an MPP lasting 8 weeks. PMID:23663679

  8. Study protocol - efficacy of an attachment-based working alliance in the multimodal pain treatment.

    PubMed

    Pfeifer, Ann-Christin; Amelung, Dorothee; Gerigk, Carina; Schroeter, Corinna; Ehrenthal, Johannes; Neubauer, Eva; Schiltenwolf, Marcus

    2016-02-16

    The concept of attachment is relevant for the onset and development of chronic pain. Insecure attachment styles negatively affect therapeutic outcome. Insecurely attached patients seem to be less able to sustain positive effects of a multimodal treatment program. However, it has never been tested before if an attachment-oriented approach can improve treatment results of insecurely attached patients in a multimodal outpatient setting. To test this assumption, we compare the short- and long-term outcomes for pain patients who will receive multidisciplinary, attachment-oriented treatment with the outcomes for patients in a control group, who will receive the multidisciplinary state-of-the-art treatment. Two patient groups (baseline, attachment intervention) are assessed before treatment, after treatment, and at a 6 month follow-up. The study is conducted in a block design: After data collection of the first block (controls) and before as well as during data collection for the second block (treatment group), the health care personnel of the outpatient pain clinic receives training on attachment theory and its use in the therapeutic context. Pain intensity as measured with visual analogue scales and physical functioning will serve as the primary outcome measures. The design of our study allows for a continuous exchange of experienced team members, which may help bring about concrete attachment related guidelines for the enhancement of therapeutic outcome. This would be the first attempt at an attachment-oriented improvement of multimodal pain programs. An attachment-based approach may be a promising way to enhance long-term treatment outcomes for insecurely attached pain patients. DRKS00008715 (registered on the 3(rd) of June 2015).

  9. Multimodal approach to therapy-related neuropathic pain in breast cancer.

    PubMed

    Patarica-Huber, E; Boskov, N; Pjevic, M

    2011-01-01

    This study evaluated the effects of the multimodal therapy (gabapentin-non steroidal anti inflammatory drug [NSAID]-morphine) on intensity and relief of treatmentrelated neuropathic pain in patients with breast cancer. This study involved 75 breast cancer outpatients who had previously undergone anti-neoplastic therapy (surgery, chemotherapy, radiotherapy). The patients were randomly divided into 3 groups, which were formed depending on the planned analgesic therapy (gabapentin, gabapentin- NSAID, gabapentin-NSAID-morphine). Each group was a control group to itself. The pain intensity difference and scores of daily activities were collated and assessed by the modified Brief Pain Inventory (BPI) questionnaire (VAS/Likert Scale). Monitoring the additional medication and side effects optimized the therapy efficiency evaluation. During this 6-week study, the decrease of pain intensity was significant in all 3 groups (p <0.0001). Although there was intergroup difference, it was statistically not significant (p >0.05). The variant analysis of pain relief showed differences both among and within the groups in the first 3 weeks of the study (F(1)=7.79, p=0.000; F(2)=7.01, p=0.001; F(3) =5.49, p=0.001). The multimodal group needed the least of additional medication and the variant analysis showed a statistically significant difference (p=0.001) from the 4th week of the trial period. The correlation between the increase trend of side effects and the frequency of additional medication was significant (p <0.05). The multimodal therapy ensures adequate cancer-related neuropathic pain control with minimal side effects.

  10. Effectiveness of a Multimodal Therapy for Patients with Chronic Low Back Pain Regarding Pre-Admission Healthcare Utilization

    PubMed Central

    Borys, Constanze; Lutz, Johannes; Strauss, Bernhard; Altmann, Uwe

    2015-01-01

    Objective The aim of the study was to examine the effectiveness of an intensive inpatient three-week multimodal therapy. We focused especially on the impact on the multimodal therapy outcome of the pre-admission number of treatment types patients had received and of medical specialist groups patients had consulted. Methods 155 patients with chronic low back pain and indication for multimodal therapy were evaluated with respect to pain intensity, depression, anxiety, well-being, and pre-admission health care utilization. In our controlled clinical trial we compared N = 66 patients on the waiting list with N = 89 patients who received immediate treatment. The waiting list patients likewise attended multimodal therapy after the waiting period. Longitudinal post-treatment data for both were collected at three- and twelve-month follow-ups. The impact of pre-admission health care utilization on multimodal therapy outcome (post) was analysed by structural equation model. Results Compared to the control group, multimodal therapy patients’ pain intensity and psychological variables were significantly reduced. Longitudinal effects with respect to pre-measures were significant at three-month follow-up for pain intensity (ES = -0.48), well-being (ES = 0.78), anxiety (ES = -0.33), and depression (ES = -0.30). Effect sizes at twelve-month follow-up were small for anxiety (ES = -0.22), and moderate for general well-being (ES = 0.61). Structural equation model revealed that a higher number of pre-admission treatment types was associated with poorer post-treatment outcomes in pain intensity, well-being, and depression. Conclusion Multimodal therapy proved to be effective with regard to improvements in pain intensity, depression, anxiety, and well-being. The association between treatment effect and number of pre-admission pain treatment types suggests that patients would benefit more from attending multimodal therapy in an earlier stage of health care. PMID:26599232

  11. Effectiveness of a Multimodal Therapy for Patients with Chronic Low Back Pain Regarding Pre-Admission Healthcare Utilization.

    PubMed

    Borys, Constanze; Lutz, Johannes; Strauss, Bernhard; Altmann, Uwe

    2015-01-01

    The aim of the study was to examine the effectiveness of an intensive inpatient three-week multimodal therapy. We focused especially on the impact on the multimodal therapy outcome of the pre-admission number of treatment types patients had received and of medical specialist groups patients had consulted. 155 patients with chronic low back pain and indication for multimodal therapy were evaluated with respect to pain intensity, depression, anxiety, well-being, and pre-admission health care utilization. In our controlled clinical trial we compared N = 66 patients on the waiting list with N = 89 patients who received immediate treatment. The waiting list patients likewise attended multimodal therapy after the waiting period. Longitudinal post-treatment data for both were collected at three- and twelve-month follow-ups. The impact of pre-admission health care utilization on multimodal therapy outcome (post) was analysed by structural equation model. Compared to the control group, multimodal therapy patients' pain intensity and psychological variables were significantly reduced. Longitudinal effects with respect to pre-measures were significant at three-month follow-up for pain intensity (ES = -0.48), well-being (ES = 0.78), anxiety (ES = -0.33), and depression (ES = -0.30). Effect sizes at twelve-month follow-up were small for anxiety (ES = -0.22), and moderate for general well-being (ES = 0.61). Structural equation model revealed that a higher number of pre-admission treatment types was associated with poorer post-treatment outcomes in pain intensity, well-being, and depression. Multimodal therapy proved to be effective with regard to improvements in pain intensity, depression, anxiety, and well-being. The association between treatment effect and number of pre-admission pain treatment types suggests that patients would benefit more from attending multimodal therapy in an earlier stage of health care.

  12. Treatment for chronic low back pain: the focus should change to multimodal management that reflects the underlying pain mechanisms.

    PubMed

    Müller-Schwefe, Gerhard; Morlion, Bart; Ahlbeck, Karsten; Alon, Eli; Coaccioli, Stefano; Coluzzi, Flaminia; Huygen, Frank; Jaksch, Wolfgang; Kalso, Eija; Kocot-Kępska, Magdalena; Kress, Hans-Georg; Mangas, Ana Cristina; Margarit Ferri, Cesar; Mavrocordatos, Philippe; Nicolaou, Andrew; Hernández, Concepción Pérez; Pergolizzi, Joseph; Schäfer, Michael; Sichère, Patrick

    2017-07-01

    Chronic low back pain: Chronic pain is the most common cause for people to utilize healthcare resources and has a considerable impact upon patients' lives. The most prevalent chronic pain condition is chronic low back pain (CLBP). CLBP may be nociceptive or neuropathic, or may incorporate both components. The presence of a neuropathic component is associated with more intense pain of longer duration, and a higher prevalence of co-morbidities. However, many physicians' knowledge of chronic pain mechanisms is currently limited and there are no universally accepted treatment guidelines, so the condition is not particularly well managed. Diagnosis should begin with a focused medical history and physical examination, to exclude serious spinal pathology that may require evaluation by an appropriate specialist. Most patients have non-specific CLBP, which cannot be attributed to a particular cause. It is important to try and establish whether a neuropathic component is present, by combining the findings of physical and neurological examinations with the patient's history. This may prove difficult, however, even when using screening instruments. Multimodal management: The multifactorial nature of CLBP indicates that the most logical treatment approach is multimodal: i.e. integrated multidisciplinary therapy with co-ordinated somatic and psychotherapeutic elements. As both nociceptive and neuropathic components may be present, combining analgesic agents with different mechanisms of action is a rational treatment modality. Individually tailored combination therapy can improve analgesia whilst reducing the doses of constituent agents, thereby lessening the incidence of side effects. This paper outlines the development of CLBP and the underlying mechanisms involved, as well as providing information on diagnosis and the use of a wide range of pharmaceutical agents in managing the condition (including NSAIDs, COX-2 inhibitors, tricyclic antidepressants, opioids and

  13. Multimodal analgesia: A systematic review of local NSAIDs for non-ophthalmologic postoperative pain management.

    PubMed

    Brubaker, Lisa; Kendall, Lauren; Reina, Eva

    2016-08-01

    While the analgesic benefits of systemically administered non-steroidal anti-inflammatory drugs (NSAIDs) for postoperative pain are well established, benefits of locally administered NSAIDs remain unclear outside the field of ophthalmologic surgery. Studies of local NSAID administration for postoperative analgesia vary considerably in terms of dosing and methodologic quality, making it difficult to derive clinically useful information. The primary objective of this systematic review is to summarize the currently available literature in order to assess the value of local NSAIDs as a component of the multimodal postoperative pain management regimen. A comprehensive search of PubMed and CENTRAL identified twelve randomized controlled trials comparing the use of local NSAIDs to systemic NSAIDs and/or placebo for postoperative multimodal pain management in patients undergoing non-ophthalmologic surgery. Nine trials met eligibility criteria (n = 532); each trial was classified into a subgroup based on time of NSAID administration (pre- or postoperatively) and comparison group (systemic NSAID or placebo). A frequency analysis was performed for similar outcomes reported in two or more studies. The risk of bias for each outcome and quality of evidence were assessed utilizing the Cochrane Risk of Bias instrument and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology, respectively. Low to moderate quality evidence exists indicating that pre- or postoperative administration of local NSAIDs may provide adequate postoperative analgesia within a multimodal regimen. Additional across-study analysis reveals clinically important but non-statistically significant trends towards a decreased use of additional analgesics during the postoperative period. The risk of adverse effects secondary to local NSAID administration is low. Local NSAIDs may be effective agents in the multimodal postoperative analgesia regimen. However, small sample size and

  14. [Multimodal group therapy for the elderly with chronic pain: concept and results in a before and after comparison].

    PubMed

    Mattenklodt, P; Ingenhorst, A; Wille, C; Flatau, B; Hafner, C; Geiss, C; Sittl, R; Ulrich, K; Griessinger, N

    2008-10-01

    Multimodal pain therapy programs are increasingly being recommended as an effective treatment option also for elderly patients with chronic pain. However, data from Germany are limited. A multimodal group program adapted to the specific needs of elderly pain patients over 70 years old (20 treatment days, over 10 weeks) was started in our pain clinic in June 2005. We evaluated clinical, psychometric and physical data at the beginning and at the end of the treatment program, and compared outcome results with a waiting list control group. A total of 24 patients (mean age 76.2+/-4.79 years) could be evaluated of which 21 patients suffered from musculoskeletal pain, 2 from neuropathic pain syndromes and 1 from headache. In the waiting-list control group 13 patients were included. There were no significant between-group differences regarding age, stages of chronification, pain intensity, duration of pain and pain diagnosis. A multimodal pain therapy program for elderly patients (over 70 years old) is an effective treatment option to reduce pain intensity and pain disability. Furthermore, life quality and physical performance improved. Long-term effects still have to be evaluated.

  15. Interventional and multimodal pain rehabilitation in a child with meralgia paresthetica.

    PubMed

    Franklin, Andrew D; Cierny, G Bennett; Luckett, Twila R

    2016-09-01

    Meralgia paresthetica is a chronic pain syndrome that is extremely rare in the pediatric population. It is manifested by hypesthesia or pain in the distribution of the lateral femoral cutaneous nerve (LFCN) and is typically caused by entrapment as the nerve passes deep to the inguinal ligament. This sensory mononeuropathy is rare in children and diagnosis is typically delayed, often leading to prolonged functional impairment and unnecessary medical testing. A 9-year-old girl presented to the pain clinic with a 6-week history of right anterolateral thigh pain first noticed after a nontraumatic cheerleading practice. Comprehensive laboratory and radiographic evaluation by multiple prior specialists revealed no clear nociceptive source of pain. History and examination were consistent with a diagnosis of idiopathic, compressive meralgia paresthetica. Conservative management including physical therapy was followed for 2 weeks with only mild improvement noted. To facilitate physical therapy, an ultrasound-guided LFCN block was performed which confirmed the diagnosis by providing complete analgesia. The patient reported overall 25% improvement from multimodal therapy at another 2 weeks. A second LFCN block was performed with complete resolution of symptoms and restoration of function. The patient remains pain-free and has returned to walking, running, and competitive sports. The primary goal of pediatric chronic pain management, regardless of pain etiology, is early restoration of function to avoid prolonged absence from school, sports, or other productive activities and limit the psychological burden of chronic disease. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Multimodal management of dental pain with focus on alternative medicine: A novel herbal dental gel.

    PubMed

    Kumarswamy, A

    2016-01-01

    Dental pain is the most common symptom associated with a wide array of dental problems and significantly impacts the oral health-related quality of life. The epidemiology and prevalence of oral diseases that could lead to dental pain are diverse and indicate regional variations. Several researchers have dwelled into the neurobiology and pathophysiology of dental pain making the pain pathways more clear and deciphering the precise targets for the management of pain. Although a number of pharmacological drugs are available in the market, a significant percentage of the population in India prefers alternative herbal medication for relief from dental pain due to the side effects and interactions of pharmacological treatment. However, there is a void in dental literature pertaining to the use, benefits, and safety of the herbal medicines. Therefore, the present assessment has been penned down, focusing on the current multimodal approaches for treating dental pain, the current unmet need, and the role of herbal medication in India for the management of dental pain, with a discussion on novel herbal dental gel.

  17. Multimodal management of dental pain with focus on alternative medicine: A novel herbal dental gel

    PubMed Central

    Kumarswamy, A.

    2016-01-01

    Dental pain is the most common symptom associated with a wide array of dental problems and significantly impacts the oral health-related quality of life. The epidemiology and prevalence of oral diseases that could lead to dental pain are diverse and indicate regional variations. Several researchers have dwelled into the neurobiology and pathophysiology of dental pain making the pain pathways more clear and deciphering the precise targets for the management of pain. Although a number of pharmacological drugs are available in the market, a significant percentage of the population in India prefers alternative herbal medication for relief from dental pain due to the side effects and interactions of pharmacological treatment. However, there is a void in dental literature pertaining to the use, benefits, and safety of the herbal medicines. Therefore, the present assessment has been penned down, focusing on the current multimodal approaches for treating dental pain, the current unmet need, and the role of herbal medication in India for the management of dental pain, with a discussion on novel herbal dental gel. PMID:27307656

  18. Maintaining lasting improvements: one-year follow-up of children with severe chronic pain undergoing multimodal inpatient treatment.

    PubMed

    Hirschfeld, Gerrit; Hechler, Tanja; Dobe, Michael; Wager, Julia; von Lützau, Pia; Blankenburg, Markus; Kosfelder, Joachim; Zernikow, Boris

    2013-03-01

    To investigate the long-term effectiveness of a 3-week multimodal inpatient program for children and adolescents with chronic pain. 167 adolescents were evaluated at pretreatment baseline, 3-, and 12-month follow-up. Long-term effectiveness was investigated for pain-related variables (pain-related disability, school absence, pain intensity) and emotional distress. We found statistically and clinically significant changes in all variables. After 1 year, the majority (56%) showed overall improvement as indexed by decreased pain-related disability or school absence. 22% had an unsuccessful treatment outcome. Those showing only short-term improvements had higher levels of emotional distress at baseline. 1 year after completing a multimodal inpatient program adolescents report less chronic pain, disability, and emotional distress. Clinically significant changes remain stable. Adolescents with high levels of emotional distress at admission may require special attention to maintain positive treatment outcomes. Specialized inpatient therapy is effective for children with chronic pain.

  19. Utility of multimodal analgesia with fascia iliaca blockade for acute pain management following hip arthroscopy.

    PubMed

    Krych, Aaron J; Baran, Sean; Kuzma, Scott A; Smith, Hugh M; Johnson, Rebecca L; Levy, Bruce A

    2014-04-01

    The purpose of this study was to evaluate the utility of multimodal analgesia with fascia iliaca blockade and for acute pain control in patients undergoing hip arthroscopy. Thirty consecutive patients undergoing primary hip arthroscopy were prospectively studied. All patients were treated preoperatively with ultrasound-guided single injection fascia iliaca blockade and multimodal analgesia. Data collected included post-operative nausea, numeric rating scale (NRS) pain scores during rest and activity, opioid consumption during the first five days (recorded as tablets of 5 mg hydrocodone/500 mg acetaminophen) and overall patient satisfaction with analgesia. This study included 23 female and 7 male patients with a median age of 35 years (range 14-58). No patient required medication for post-operative nausea. The overall NRS scores were an average of 3.9 on day 0, 3.6 on day 1, 3.4 on day 2, 2.9 on day 3, 3.0 on day 4 and 2.7 on day 5. The average tablets of opioid taken were 1.5 on day 0, 1.2 on day 1, 1.3 on day 2, 1.0 on day 3, 1.1 on day 4 and 0.9 on day 5. Overall, 20 patients rated their post-operative pain control as very satisfied (67 %), and 10 patients as satisfied (33 %). There were no complications or side effects from the fascia iliaca blockade. In this prospective study, multimodal analgesia with fascia iliaca blockade following hip arthroscopy was safe and effective. The quality of early post-operative analgesia provided by the fascia iliaca blockade was excellent and resulted in low opioid consumption, high quality of pain relief and high overall patient satisfaction.

  20. [Multimodal distraction to relieve pain in children undergoing acute medical procedures].

    PubMed

    Miller, Kate; Rodger, Sylvia; Bucolo, Sam; Wang, Xue-Qing; Kimble, Roy M

    2009-10-01

    Non-pharmacological approaches to pain management have been used by therapists for decades to reduce the anxiety and pain experienced by children during burn care procedures. With a greater understanding of pain and the principles behind what causes a child to be distracted, combined with access to state of the art technology, we have developed an easy to use, hand held multimodal distraction device (MMD). MMD is an interactive device that prepares the child for a procedure and uses developmentally appropriate distraction stories and games during the procedures to alleviate anxiety and pain. This paper summarizes the results of three randomized control trials. The trials aimed to understand the effectiveness of MMD as a distraction and preparation tool in reducing anxiety and pain in children undergoing burns and non-burns medical procedures compared to pure pharmacological approaches Standard Distraction (SD) and off the shelf video games (VG). Three separate prospective randomized control trials involving 182 children having 354 dressing changes were conducted in the burns and orthopedic departments at Royal Children's Hospital, Brisbane, Australia, to address the above aims. Pain and anxiety scores were completed for the child, caregiver and nursing staff according to the Modified Faces, Legs, Activity, Cry and Consolability Scale, Faces Pain Scale-Revised, Visual Analogue Scale and Wong-Baker Faces Pain Rating Scale. Procedural length was recorded. MMD as a preparation and distraction tool were shown to have a significant impact on child, parent and nursing staff reported anxiety and pain during procedures compared to standard care and video games (P < 0.01). The MMD had a positive effect on clinical time and was shown to sustain its impact on pain and time with further dressing changes. MMD is more effective in reducing the pain and anxiety experienced by children in acute medical procedures as compared with SD and VG. MMD is continuing to be trialed and is

  1. Experimental manipulations of pain catastrophizing influence pain levels in patients with chronic pain and healthy volunteers.

    PubMed

    Kjøgx, Heidi; Kasch, Helge; Zachariae, Robert; Svensson, Peter; Jensen, Troels S; Vase, Lene

    2016-06-01

    Pain catastrophizing (PC) has been related to pain levels in both patients experiencing acute or chronic pain and in healthy volunteers exposed to experimental pain. Still, it is unclear whether high levels of pain catastrophizing lead to high levels of pain or vice versa. We therefore tested whether levels of pain catastrophizing could be increased and decreased in the same participant through hypnotic suggestions and whether the altered level of situation-specific pain catastrophizing was related to increased and decreased pain levels, respectively. Using the spontaneous pain of 22 patients with chronic tension-type headache and experimentally induced pain in 22 healthy volunteers, participants were tested in 3 randomized sessions where they received 3 types of hypnotic suggestions: Negative (based on the 13 items in the Pain Catastrophizing Scale), Positive (coping-oriented reversion of the Pain Catastrophizing Scale), and Neutral (neutral sentence) hypnotic suggestions. The hypnotic suggestions significantly increased and decreased situation-specific PC in both patients and healthy volunteers (P < 0.001). Also, the levels of pain intensity and pain unpleasantness were significantly altered in both patients and healthy volunteers (P < 0.001). Furthermore, regression analyses showed that changes in pain catastrophizing predicted changes in pain in patients (R = 0.204-0.304; P < 0.045) and in healthy volunteers (R = 0.328-0.252; P < 0.018). This is the first study to successfully manipulate PC in positive and negative directions in both patients with chronic pain and healthy volunteers and to show that these manipulations significantly influence pain levels. These findings may have important theoretical and clinical implications.

  2. Efficacy of interscalene block combined with multimodal pain control for postoperative analgesia after rotator cuff repair.

    PubMed

    Cho, Chul-Hyun; Song, Kwang-Soon; Min, Byung-Woo; Jung, Gu-Hee; Lee, Young-Kuk; Shin, Hong-Kwan

    2015-02-01

    The aim of the study reported here was to compare the efficacy and safety of postoperative analgesia provided by interscalene block with multimodal pain control (IB-MPC) versus that provided by multimodal pain control (MPC) alone after arthroscopic rotator cuff repair. Sixty consecutive patients were assigned to either the IB-MPC group (30 patients) or the MPC group (30 patients). Visual analogue scale (VAS) pain scores before surgery and through day 5 after surgery, consumption of rescue analgesic, adverse effects and complications were evaluated. Mean VAS pain scores immediately after surgery and on days 1 through 5 after surgery were 3.9 ± 2.6, 4.4 ± 1.5, 3.4 ± 1.3, 2.7 ± 1.3, 2.4 ± 1.2, and 2.0 ± 1.0, respectively, in the IB-MPC group and 6.2 ± 1.8, 4.1 ± 1.7, 3.2 ± 1.9, 2.7 ± 1.4, 2.5 ± 1.3, and 2.0 ± 1.2, respectively, in the MPC group. The IB-MPC group had significantly lower VAS pain score immediately after surgery than the MPC group did (P < 0.001). There were no statistically significant differences regarding consumption of rescue analgesic or adverse effects between the two groups (n.s.). In the IB-MPC group, complications related to interscalene block included tingling of the hand in three patients and numbness of the neck and ear in two. However, these symptoms resolved spontaneously within a few days. No patients had major complications related to interscalene block. IB-MPC achieved better pain control immediately after surgery than MPC alone, without major complications related to interscalene block. It is an effective and safe method for providing postoperative analgesia after arthroscopic rotator cuff repair. Prospective Comparative Study, Prognosis Study, Level II.

  3. Multimodal approaches to optimize outcomes of chronic opioid therapy in the management of chronic pain.

    PubMed

    Kirsh, Kenneth L; Fishman, Scott M

    2011-01-01

    To review clinical strategies for long-term opioid management as well as strategies to assess and monitor patients with moderate to severe chronic pain who may be at risk for aberrant drug-related behaviors. A symposium was held to disseminate a review of opioid use strategies, including use of the Universal Precautions in Pain Medicine as well as the Federation of State Medical Boards Model Policy for Prescribing Controlled Substances (FSMB model policy). These include continual reassessment of pain and risk, treatment agreements, compliance monitoring, urine drug screening, documentation, compliance with the law, and patient education. Additionally, the use of multimodal strategies to treat patients, with techniques such as cognitive-behavioral therapy, is discussed as an essential part of a comprehensive pain management plan. The review summarizes a continuing medical education (CME)-accredited symposium conducted at the American Pain Society Annual Meeting in Baltimore, Maryland, in May 2010. Recommendations for the management and monitoring of long-term opioid therapy for patients with chronic noncancer pain are rooted in evidence-based clinical guidelines, which also provide guidance for the identification of aberrant behaviors or overt addiction. Vigilance and frequent interactions may sometimes be inadequate to prevent problematic behaviors; therefore, pharmacologic strategies designed to deter abusive behaviors are also discussed. Wiley Periodicals, Inc.

  4. A qualitative study of veterans on long-term opioid analgesics: barriers and facilitators to multimodality pain management.

    PubMed

    Simmonds, Maureen J; Finley, Erin P; Vale, Shruthi; Pugh, Mary Jo; Turner, Barbara J

    2015-04-01

    The aim of this study was to examine barriers and facilitators to multimodality chronic pain care among veterans on high-dose opioid analgesics for chronic non-cancer pain. A Veterans Health Administration clinic in San Antonio. Twenty-five veterans taking at least 50 mg morphine equivalent daily oral opioid doses for more than 6 months. Three semi-structured focus groups, each with seven to nine veterans. Interview guide addressed: chronic pain effects on quality of life, attitudes/experiences with multimodality pain care, social support, and interest in peer support. In an iterative process using grounded theory, three reviewers reviewed de-identified transcripts for themes. The theory of planned behavior (TPB) framework was used to classify barriers and facilitators to multimodal pain management. The 25 participants had a mean age of 54 years (39-70); 32% were women and 24% non-white. The three TPB dimensions (attitudes, social norms, and perceived behavioral control) were reflected in emergent themes: 1) uncontrollable impact of pain in all aspects of life; 2) reliance on opioids and challenges in obtaining these drugs despite ambivalence about benefits; 3) poor access to and beliefs about non-pharmacologic therapies; 4) frustrations with Department of Veterans Affairs health care; and 5) poor social support and isolation reflected by limited interest in peer support. Veterans with chronic pain on long-term opioids hold pervasive attitudes that prevent them from using multimodality pain management options, lack social support and social norms for non-opioid-based pain treatment options, and have poor perceived control due to poor access to multimodality care. Wiley Periodicals, Inc.

  5. Experimental Study on Bioluminescence Tomography with Multimodality Fusion

    PubMed Central

    Lv, Yujie; Tian, Jie; Cong, Wenxiang; Wang, Ge

    2007-01-01

    To verify the influence of a priori information on the nonuniqueness problem of bioluminescence tomography (BLT), the multimodality imaging fusion based BLT experiment is performed by multiview noncontact detection mode, which incorporates the anatomical information obtained by the microCT scanner and the background optical properties based on diffuse reflectance measurements. In the reconstruction procedure, the utilization of adaptive finite element methods (FEMs) and a priori permissible source region refines the reconstructed results and improves numerical robustness and efficiency. The comparison between the absence and employment of a priori information shows that multimodality imaging fusion is essential to quantitative BLT reconstruction. PMID:18256736

  6. Gender, variation in opioid receptor genes and sensitivity to experimental pain

    PubMed Central

    2013-01-01

    Background Pain tolerance is subject to considerable inter-individual variation, which may be influenced by a number of genetic and non-genetic factors. The mu, delta and kappa opioid receptors play a role in pain perception and are thought to mediate different pain modalities. The aim of this study was to explore associations between pain thresholds and gender and genetic variants in the three opioid receptor genes (OPRM, OPRD and OPRK). Experimental multi-modal pain data from previously published studies carried out in healthy Caucasian volunteers were used in order to limit the number of confounders to the study outcome. Data on thermal skin pain (n=36), muscle pressure pain (n=31) and mechanical visceral pain (n=50)) tolerance thresholds were included. Results Nineteen genetic polymorphisms were included in linear regression modeling. Males were found to tolerate higher thermal and muscle pressure pain than females (p=0.003 and 0.02). Thirty four percent of variability in thermal skin pain was accounted for by a model consisting of OPRK rs6473799 and gender. This finding was just outside significance when correction for multiple testing was applied. Variability in muscle pressure pain tolerance was associated with OPRK rs7016778 and rs7824175. These SNPs accounted for 43% of variability in muscle pressure pain sensitivity and these findings remained significant after adjustment for multiple testing. No association was found with mechanical visceral pain. Conclusion This is a preliminary and hypothesis generating study due to the relatively small study size. However, significant association between the opioid receptor genes and experimental pain sensitivity supports the influence of genetic variability in pain perception. These findings may be used to generate hypotheses for testing in larger clinical trials of patients with painful conditions. PMID:23570317

  7. Multi-modal distraction. Using technology to combat pain in young children with burn injuries.

    PubMed

    Miller, Kate; Rodger, Sylvia; Bucolo, Sam; Greer, Ristan; Kimble, Roy M

    2010-08-01

    The use of non-pharmacological pain management remains adhoc within acute paediatric burns pain management protocols despite ongoing acknowledgement of its role. Advancements in adult based pain services including the integration of virtual reality has been adapted to meet the needs of children in pain, as exemplified by the development of multi-modal distraction (MMD). This easy to use, hand held interactive device uses customized programs designed to inform the child about the procedure he/she is about to experience and to distract the child during dressing changes. (1) To investigate if either MMD procedural preparation (MMD-PP) or distraction (MMD-D) has a greater impact on child pain reduction compared to standard distraction (SD) or hand held video game distraction (VG), (2) to understand the impact of MMD-PP and MMD-D on clinic efficiency by measuring length of treatment across groups, and lastly, (3) to assess the efficacy of distraction techniques over three dressing change procedures. A prospective randomised control trial was completed in a paediatric tertiary hospital Burns Outpatient Clinic. Eighty participants were recruited and studied over their first three dressing changes. Pain was assessed using validated child report, caregiver report, nursing observation and physiological measures. MMD-D and MMD-PP were both shown to significantly relieve reported pain (ppain reduction across three dressing changes to children when compared to standard practices or hand held video games. This device has the potential to improve clinic efficiency with reductions in treatment lengths.

  8. [Outpatient multimodal pain therapy : Results of a 1-week intensive outpatient multimodal group program for patients with chronic unspecific back pain - retrospective evaluation after 3 and 12 months].

    PubMed

    Reck, T; Dumat, W; Krebs, J; Ljutow, A

    2017-03-03

    Interdisciplinary pain therapy is nowadays the state of the art for the treatment of chronic unspecific back pain. The aim of this article is to present the retrospective analysis of the data from a 1-week intensive outpatient multimodal interdisciplinary pain therapy group program for treatment of patients with chronic unspecific back pain. The questionnaire-based data from patients who attended the program were evaluated before as well as 3 and 12 months after finishing the program. The patients were questioned regarding parameters, such as pain severity, quality of life, pain-related disability, depression and pain acceptance. On average a significant improvement of all parameters after 3 and 12 months could be demonstrated (excluding the domains "social" and "environment" in the context of quality of life). Interestingly, the results showed a significant improvement of almost all evaluated parameters even after a period of 12 months (unfortunately only data for 41 patients were available). In our opinion this improvement is due to the special constellation of the presented program, which with 1 week is relatively short but very intensive with 34 h of treatment. In addition, the program is integrated into a long-term multimodal outpatient treatment, a concept in which the multimodal treatment is individually continued after the 1‑week program. On the other hand, the results especially after 12 months have to be interpreted particularly in this context.

  9. Being in an exchange process: experiences of patient participation in multimodal pain rehabilitation.

    PubMed

    Nordin, Catharina; Gard, Gunvor; Fjellman-Wiklund, Anncristine

    2013-06-01

    To explore primary healthcare patients' experiences of patients participation in multimodal pain rehabilitation. A total of 17 patients who had completed multimodal rehabilitation for persistent pain were interviewed. The interviews were analysed using qualitative content analysis. One theme, Being in an exchange process, and 4 categories emerged. The theme depicted patient participation as a continuous exchange of emotions, thoughts and knowledge. The category Fruitful encounters represented the basic prerequisites for patient participation through dialogue and platforms to meet. Patients' emotional and cognitive resources and restrictions, as well as knowledge gaps, were conditions influencing patient participation in the category Inequality in co-operation. Mutual trust and respect were crucial conditions in patient's personal relationships with the health professionals, forming the category Confidence-inspiring alliance. In the category Competent health professionals, the health professionals' expertise, empathy and personal qualities, were emphasized to favour patient participation. Patient participation can be understood as complex and individualized. A confidence-inspiring alliance enables a trusting relationship to be formed between patients and health professionals. Patients emphasized that health professionals need to play an active role in building common ground in the interaction. Understanding each patient's needs in the participation process may favour patient participation.

  10. Changes in pain-related coping strategies and their importance for treatment outcome following multimodal inpatient treatment: does sex matter?

    PubMed

    Hechler, Tanja; Kosfelder, Joachim; Vocks, Silja; Mönninger, Theresa; Blankenburg, Markus; Dobe, Michael; Gerlach, Alexander L; Denecke, Heide; Zernikow, Boris

    2010-05-01

    While sex differences in pain-related coping have been widely reported, little is known on sex differences in changes in coping following multimodal pain treatment and how these changes relate to treatment outcome. The present prospective study therefore aimed to investigate sex differences in coping strategies between boys and girls with chronic pain prior to multimodal inpatient treatment and at 3-month follow-up. Sixty-four boys and 103 girls with various pain disorders were evaluated. Core outcomes (pain intensity and pain-related disability) and coping were assessed via validated questionnaires. At admission, boys and girls used similar coping strategies. Three months following treatment, boys and girls decreased passive pain coping and seeking social support while they maintained the degree of positive self-instruction. Girls displayed higher seeking social support than boys and of importance, only for girls, a reduction in seeking social support was related to decreases in pain intensity. In both groups, the changes in coping were related to positive treatment outcome. Results suggest that both groups may benefit from reductions in passive pain coping and seeking social support. The causal quality of this relationship remains to be determined in future studies. Gender-role expectations and family interactions may account for the sex differences demonstrated for seeking social support. Boys and girls with chronic pain show profound similarities in pain-related coping strategies prior and after multimodal pain treatment. The changes in coping are related to positive treatment outcomes. Sex-specific treatment strategies for changing seeking social support may need to be developed and tested for their differential efficacy in boys and girls. Copyright 2010 American Pain Society. Published by Elsevier Inc. All rights reserved.

  11. Evaluation of a multimodal pain therapy concept for chronic pain after total knee arthroplasty: a pilot study in 21 patients.

    PubMed

    Zajonz, Dirk; Fakler, Johannes K M; Dahse, Anna-Judith; Zhao, Fujiaoshou Junping; Edel, Melanie; Josten, Christoph; Roth, Andreas

    2017-01-01

    In spite of the improvement of many aspects around Total knee arthroplasty (TKA), there is still a group of 10% to 34% of patients who is not satisfied with the outcome. The therapy of chronic pain after TKA remains a medical challenge that requires an interdisciplinary therapy concept. The aim of this prospective pilot study was to evaluate the efficacy of a multimodal pain therapy in chronic complaints after TKA. In a prospective cohort pilot study, we included patients with chronic pain after TKA who obtained in-patient care, especially multimodal pain therapy (MMPT), for at least 10 days. Essential elements of this therapy concept were physiotherapy, pain medication therapy, topical application of ketamine, local infiltration and Traditional Chinese Medicine. Patients with varying causes of complaints were excluded in advance. Before the start of the study all test persons were informed and gave their written consent. Moreover, each patient was examined and questioned at hospital admission, discharge and at its first as well as second follow-up. Additionally, knee joint mobility and stability were investigated at all examination times. From 03/07/2016 to 07/14/2016, 21 patients were included in the pilot study. 52% of the considered population were female (11 persons). The median age was 65 years (45-79 years) and the median stay in hospital amounted 9 days (8-14 days). The first follow-up was scheduled after six weeks (median: 38 days, 30-112 days) and the second one after six months (median: 8 months, 7-12 months). The number of patients of the first follow-up was 17 out of 21 (19% drop out). The drop out of the last follow-up accounted for 33%. All patients benefit from the presented applications and therapies with regard to pain, function and range of motion. Especially, during the period of in-patient treatment, nearly all patients have improved in all terms. However, during the first follow-up clear deteriorations occurred in all areas, which

  12. Alleviation of chronic pain following rat spinal cord compression injury with multimodal actions of huperzine A

    PubMed Central

    Yu, Dou; Thakor, Devang K.; Han, Inbo; Ropper, Alexander E.; Haragopal, Hariprakash; Sidman, Richard L.; Zafonte, Ross; Schachter, Steven C.; Teng, Yang D.

    2013-01-01

    Diverse mechanisms including activation of NMDA receptors, microglial activation, reactive astrogliosis, loss of descending inhibition, and spasticity are responsible for ∼40% of cases of intractable neuropathic pain after spinal cord injury (SCI). Because conventional treatments blocking individual mechanisms elicit only short-term effectiveness, a multimodal approach with simultaneous actions against major pain-related pathways may have value for clinical management of chronic pain. We hypothesize that [-]-huperzine A (HUP-A), an alkaloid isolated from the club moss Huperzia serrata, that is a potent reversible inhibitor of acetylcholinesterase and NMDA receptors, could mitigate pain without invoking drug tolerance or dependence by stimulating cholinergic interneurons to impede pain signaling, inhibiting inflammation via microglial cholinergic activation, and blocking NMDA-mediated central hypersensitization. We tested our hypothesis by administering HUP-A i.p. or intrathecally to female Sprague–Dawley rats (200–235 g body weight) after moderate static compression (35 g for 5 min) of T10 spinal cord. Compared with controls, HUP-A treatment demonstrates significant analgesic effects in both regimens. SCI rats manifested no drug tolerance following repeated bolus i.p. or chronic intrathecal HUP-A dosing. The pain-ameliorating effect of HUP-A is cholinergic dependent. Relative to vehicle treatment, HUP-A administration also reduced neural inflammation, retained higher numbers of calcium-impermeable GluR2-containing AMPA receptors, and prevented Homer1a up-regulation in dorsal horn sensory neurons. Therefore, HUP-A may provide safe and effective management for chronic postneurotrauma pain by reestablishing homeostasis of sensory circuits. PMID:23386718

  13. Multimodal pain control is associated with reduced hospital stay following open abdominal hysterectomy.

    PubMed

    Santoso, Joseph T; Ulm, Michael A; Jennings, Patrick W; Wan, Jim Y

    2014-12-01

    To study the association of a multimodal pain protocol (MMPC) and reduced hospital stay after open abdominal hysterectomy. The study design was a comparison of a prospective cohort with a retrospective historical control. We enrolled endometrial cancer patients undergoing open abdominal hysterectomy with lymphadenectomy by the same surgeon. Control patients from 2008 to 2010 who received morphine PCA alone were compared with a similar demographic group of patients from 2011 to 2013 who received MMPC. MMPC consisted of gabapentin (900mg PO) and acetaminophen (1g IV) administered 45-60min preoperatively. The surgical site was injected with bupivacaine with 0.5% epinephrine prior to incision. The postoperative pain control regimen consisted of gabapentin (300mg PO every 6h), acetaminophen (1g IV every 8h for 24h postoperatively), ketorolac (15mg IV every 6h for 48h postoperatively), morphine PCA (2mg IV every 10min, no basal rate) and oxycodone/acetaminophen (10/325mg PO every 6h as needed). Length of hospital stay (LOH) of the study cohort (N=105 with MMPC) was compared with the historical with postoperative morphine alone (N=113 without MMPC). There were no differences in demographic, uterine cancer stage, or comorbidities between the two arms. The LOH was 1.6 days for patients receiving MMPC and 3.3 days for patients who received morphine alone (P<0.001). Multimodal pain control is associated with significantly reduced hospital stay after open abdominal hysterectomy. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  14. Why does Acute Postwhiplash Injury Pain Transform into Chronic Pain Multimodal Assessment of Risk Factors and Predictors of Pain Chronification

    DTIC Science & Technology

    2016-10-19

    Mild Traumatic brain injury, Pain perception, Pain modulation, fMRI, EEG ...clinical stage of the experiment. The ER team is responsible for identifying and recruitment of subjects. ii. We purchased 64channels EEG system for the

  15. Multimodal, integrative therapies for the self-management of chronic pain symptoms.

    PubMed

    Lee, Courtney; Crawford, Cindy; Swann, Steven

    2014-04-01

    Chronic pain management typically consists of prescription medications or provider-based, behavioral, or interventional procedures which are often ineffective, may be costly, and can be associated with undesirable side effects. Because chronic pain affects the whole person (body, mind, and spirit), patient-centered complementary and integrative medicine (CIM) therapies that acknowledge the patients' roles in their own healing processes have the potential to provide more efficient and comprehensive chronic pain management. Active self-care CIM therapies (ACT-CIM) allow for a more diverse, patient-centered treatment of complex symptoms, promote self-management, and are relatively safe and cost-effective. To date, there are no systematic reviews examining the full range of ACT-CIM used for chronic pain symptom management. A systematic review was conducted, using Samueli Institute's rapid evidence assessment of the literature methodology, to rigorously assess both the quality of the research on ACT-CIM modalities and the evidence for their efficacy and effectiveness in treating chronic pain symptoms. A working group of subject matter experts was also convened to evaluate the overall literature pool and develop recommendations for the use and implementation of these modalities. Following key database searches, 146 randomized controlled trials were included in the review, 26 of which investigated multimodal, integrative therapies, as defined by the authors. This article summarizes the current evidence, quality, and effectiveness of these modalities. Recommendations and next steps to move this field of research forward are also discussed. The entire scope of the review is detailed throughout the current Pain Medicine supplement. Wiley Periodicals, Inc.

  16. Study of experimental pain measures and nociceptive reflex in chronic pain patients and normal subjects.

    PubMed

    Boureau, F; Luu, M; Doubrère, J F

    1991-02-01

    This study evaluates (i) the effect of heterotopic chronic pain on various experimental pain measures, (ii) the relationship between experimental pain measures and chronic pain symptomatology assessment, and (iii) the influence of the various pain aetiologies on experimental pain measures. Fifty-three chronic pain patients were compared to 17 pain-free subjects with the following psychophysical and physiological indices: pain threshold (PTh), pain tolerance (PTol), verbal estimation of intensity and unpleasantness (intensity scale, IS; unpleasantness scale, US), threshold for intensity and unpleasantness (ITh and UTh), lower limb RIII nociceptive reflex (RIIITh and RIII frequency of occurrence). Chronic pain syndromes included neuropathic pain (n = 12), iodopathic pain (n = 12), myofascial syndromes (n = 9), headache (n = 9), and miscellaneous pain (n = 11). Chronic pain symptomatology was assessed with a visual analogue scale (VAS), a French MPQ adaptation (QDSA), Beck Depression Inventory (BDI), Spielberger State Trait Inventory (STAI) and Eysenck Personality Inventory (EPI). No significant difference was observed between chronic pain patients and pain-free control groups and between patient subgroups for PTh, PTol and RIIITh. No significant correlation was found between experimental pain measures and clinical pain, anxiety or depression scores. However, the chronic pain patients had a higher threshold for unpleasantness and judged the suprathreshold stimuli significantly less intense and less unpleasant than the control group. These results are discussed in relation to diffuse noxious inhibitory controls and the adaptation level theory of chronic pain experience.

  17. Fentanyl-trazodone-paracetamol triple drug combination: multimodal analgesia in a mouse model of visceral pain.

    PubMed

    Fernández-Dueñas, Víctor; Poveda, Raquel; Fernández, Alejandro; Sánchez, Sílvia; Planas, Eulàlia; Ciruela, Francisco

    2011-05-01

    Multimodal or balanced analgesia is commonly used in the management of acute and chronic pain in humans, in order to achieve the best analgesic/safety profile. Here, by using a model of visceral acute tonic pain, the acetic acid-induced writhing test of mice, we show a synergistic interaction between fentanyl, trazodone and paracetamol on the inhibition of nociception. First of all, once assessed that all drugs induced dose-related antinociceptive effects, they were mixed in fixed ratio (1:1) combinations and a synergistic drug-drug interaction was obtained in all circumstances. Thereafter, we assayed the effects of the triple combination of fentanyl-trazodone-paracetamol and it was demonstrated that they displayed a potent synergistic interaction on the inhibition of acetic acid-mediated nociception. Interestingly, drug dosage reduction permitted to reduce the incidence of possible adverse effects, namely exploratory activity and motor coordination, thus it was demonstrated that it improved the benefit/risk profile of such treatment. Afterwards, we attempted to elucidate the mechanism of action of such interaction, by means of the non-selective opioid receptor antagonist naloxone. Interestingly, naloxone completely antagonized the antinociceptive effects of fentanyl, and it also partially reversed paracetamol and trazodone mediated analgesia. Furthermore, when naloxone was co-administered with the triple-drug treatment it blocked the previously observed enhanced antinociceptive effects of the combination. Thus, these results indicated that the endogenous opioid system played a main role in the present drug-drug interaction. Overall, the triple combination of fentanyl-trazodone-paracetamol induced a potent synergistic antinociceptive effect, which could be of interest for optimal multimodal clinical analgesia. Copyright © 2011 Elsevier Inc. All rights reserved.

  18. Impact of emotional distress and pain-related fear on patients with chronic pain: Subgroup analysis of patients referred to multimodal rehabilitation.

    PubMed

    Svanberg, Mikael; Stålnacke, Britt-Marie; Enthoven, Paul; Brodda-Jansen, Gunilla; Gerdle, Björn; Boersma, Katja

    2017-04-06

    Multimodal rehabilitation programmes (MMRP) for chronic pain could be improved by determining which patients do not benefit fully. General distress and pain-related fear may explain variations in the treatment effects of MMRP. Cohort study with a cross-sectional, prospective part. Chronic musculoskeletal pain patients referred to 2 hospital-based pain rehabilitation clinics. The cross-sectional part of this study cluster analyses patients (n = 1,218) with regard to distress and pain-related fear at first consultation in clinical pain rehabilitation and describes differences in external variables between clusters. The prospective part follows the subsample of patients (n = 260) participating in MMRP and describes outcome post-treatment. Four distinct subgroups were found: (i) those with low levels of distress and pain-related fear; (ii) those with high levels of pain-related fear; (iii) those with high levels of distress; and (iv) those with high levels of distress and pain-related fear. These subgroups showed differences in demogra-phics, pain characteristics, quality of life, and acceptance, as well as the degree of MMRP participation and MMRP outcome. Among patients with chronic pain referred to MMRP there are subgroups with different profiles of distress and pain-related fear, which are relevant to understanding the adaptation to pain and MMRP outcome. This knowledge may help us to select patients and tailor treatment for better results.

  19. Effects of the Web Behavior Change Program for Activity and Multimodal Pain Rehabilitation: Randomized Controlled Trial.

    PubMed

    Nordin, Catharina A; Michaelson, Peter; Gard, Gunvor; Eriksson, Margareta K

    2016-10-05

    Web-based interventions with a focus on behavior change have been used for pain management, but studies of Web-based interventions integrated in clinical practice are lacking. To emphasize the development of cognitive skills and behavior, and to increase activity and self-care in rehabilitation, the Web Behavior Change Program for Activity (Web-BCPA) was developed and added to multimodal pain rehabilitation (MMR). The objective of our study was to evaluate the effects of MMR in combination with the Web-BCPA compared with MMR among persons with persistent musculoskeletal pain in primary health care on pain intensity, self-efficacy, and copying, as part of a larger collection of data. Web-BCPA adherence and feasibility, as well as treatment satisfaction, were also investigated. A total of 109 participants, mean age 43 (SD 11) years, with persistent pain in the back, neck, shoulder, and/or generalized pain were recruited to a randomized controlled trial with two intervention arms: (1) MMR+WEB (n=60) and (2) MMR (n=49). Participants in the MMR+WEB group self-guided through the eight modules of the Web-BCPA: pain, activity, behavior, stress and thoughts, sleep and negative thoughts, communication and self-esteem, solutions, and maintenance and progress. Data were collected with a questionnaire at baseline and at 4 and 12 months. Outcome measures were pain intensity (Visual Analog Scale), self-efficacy to control pain and to control other symptoms (Arthritis Self-Efficacy Scale), general self-efficacy (General Self-Efficacy Scale), and coping (two-item Coping Strategies Questionnaire; CSQ). Web-BCPA adherence was measured as minutes spent in the program. Satisfaction and Web-BCPA feasibility were assessed by a set of items. Of 109 participants, 99 received the allocated intervention (MMR+WEB: n=55; MMR: n=44); 88 of 99 (82%) completed the baseline and follow-up questionnaires. Intention-to-treat analyses were performed with a sample size of 99. The MMR+WEB intervention

  20. Effects of the Web Behavior Change Program for Activity and Multimodal Pain Rehabilitation: Randomized Controlled Trial

    PubMed Central

    Michaelson, Peter; Gard, Gunvor; Eriksson, Margareta K

    2016-01-01

    Background Web-based interventions with a focus on behavior change have been used for pain management, but studies of Web-based interventions integrated in clinical practice are lacking. To emphasize the development of cognitive skills and behavior, and to increase activity and self-care in rehabilitation, the Web Behavior Change Program for Activity (Web-BCPA) was developed and added to multimodal pain rehabilitation (MMR). Objective The objective of our study was to evaluate the effects of MMR in combination with the Web-BCPA compared with MMR among persons with persistent musculoskeletal pain in primary health care on pain intensity, self-efficacy, and copying, as part of a larger collection of data. Web-BCPA adherence and feasibility, as well as treatment satisfaction, were also investigated. Methods A total of 109 participants, mean age 43 (SD 11) years, with persistent pain in the back, neck, shoulder, and/or generalized pain were recruited to a randomized controlled trial with two intervention arms: (1) MMR+WEB (n=60) and (2) MMR (n=49). Participants in the MMR+WEB group self-guided through the eight modules of the Web-BCPA: pain, activity, behavior, stress and thoughts, sleep and negative thoughts, communication and self-esteem, solutions, and maintenance and progress. Data were collected with a questionnaire at baseline and at 4 and 12 months. Outcome measures were pain intensity (Visual Analog Scale), self-efficacy to control pain and to control other symptoms (Arthritis Self-Efficacy Scale), general self-efficacy (General Self-Efficacy Scale), and coping (two-item Coping Strategies Questionnaire; CSQ). Web-BCPA adherence was measured as minutes spent in the program. Satisfaction and Web-BCPA feasibility were assessed by a set of items. Results Of 109 participants, 99 received the allocated intervention (MMR+WEB: n=55; MMR: n=44); 88 of 99 (82%) completed the baseline and follow-up questionnaires. Intention-to-treat analyses were performed with a sample

  1. Heritability of pain catastrophizing and associations with experimental pain outcomes: a twin study.

    PubMed

    Trost, Zina; Strachan, Eric; Sullivan, Michael; Vervoort, Tine; Avery, Ally R; Afari, Niloofar

    2015-03-01

    This study used a twin paradigm to examine genetic and environmental contributions to pain catastrophizing and the observed association between pain catastrophizing and cold-pressor task (CPT) outcomes. Male and female monozygotic (n = 206) and dizygotic twins (n = 194) from the University of Washington Twin Registry completed a measure of pain catastrophizing and performed a CPT challenge. As expected, pain catastrophizing emerged as a significant predictor of several CPT outcomes, including cold-pressor Immersion Tolerance, Pain Tolerance, and Delayed Pain Rating. The heritability estimate for pain catastrophizing was found to be 37% with the remaining 63% of variance attributable to unique environmental influence. Additionally, the observed associations between pain catastrophizing and CPT outcomes were not found attributable to shared genetics or environmental exposure, which suggests a direct relationship between catastrophizing and experimental pain outcomes. This study is the first to examine the heritability of pain catastrophizing and potential processes by which pain catastrophizing is related to experimental pain response.

  2. Prospective medium-term results of multimodal pain management in patients with lumbar radiculopathy

    PubMed Central

    Benditz, A.; Madl, M.; Loher, M.; Grifka, J.; Boluki, D.; Linhardt, O.

    2016-01-01

    Lumbar radiculopathy is one of the most common diseases of modern civilisation. Multimodal pain management (MPM) represents a central approach to avoiding surgery. Only few medium-term results have been published in the literature so far. This study compared subjective and objective as well as anamnestic and clinical parameters of 60 patients who had undergone inpatient MPM because of lumbar radiculopathy before and 1 year ±2 weeks after treatment. The majority of patients were very satisfied (35%) or satisfied (52%) with the treatment outcome. Merely 8 patients commented neutrally and none negatively. The finger-floor distance had decreased significantly (p < 0.01), and 30 patients (50%) had shown improved mobility of the spine after therapy. The need for painkillers had also been significantly reduced after 1 year. The arithmetical average of pain on a visual analogue scale was 7.21 before treatment, which had significantly decreased to 3.58 at follow-up (p < 0.01). MPM is an effective approach for treating lumbar radiculopathy by mechanical nerve root irritation. Therefore, in the absence of an absolute indication for surgery or an absolute contradiction for MPM, patients should first be treated with this minimally invasive therapy. PMID:27305956

  3. [Clinical studies on multimodal pain therapy : Standardized measurement of therapy outcomes with a core outcome set].

    PubMed

    Deckert, S; Sabatowski, R; Schmitt, J; Kaiser, U

    2016-12-01

    Decision making in evidence-based medicine is based on general data on therapy outcomes as well as the effectiveness and safety in specific patient populations. Typically, findings concerning therapy outcomes from different studies are aggregated for a final conclusion. In this context a comparison of results is hampered by studies in which therapy outcomes are heterogeneously measured. Such methodological challenges exist for almost all areas of medical treatment, as well as for multimodal pain therapy (MMPT). Through establishing core outcome sets (COS) the required standardization of measurement of therapy outcomes in clinical research can be achieved. A COS is an evidence-based and consented minimum set consisting of outcome domains (i.e. partial aspects of the medical condition to be investigated, which have to be measured in order to give the best possible demonstration of therapy outcome of an intervention) accomplished by valid, reliable and sensitive measurement instruments which should be applied in each clinical trial. No such COS has so far been found for MMPT. The aim of this article is to give an overview about currently recommended methodological approaches to develop a COS accompanied by a brief introduction about existing COS initiatives focusing on chronic pain. The existing COS recommendations are discussed and conclusions are drawn on whether existing recommendations could also be applied for MMPT. Finally, the impact of healthcare research in Germany on a standardized assessment of therapy outcome in MMPT is outlined.

  4. Pre-emptive and multi-modal perioperative pain management may improve quality of life in patients undergoing spinal surgery.

    PubMed

    Lee, Byung Ho; Park, Jin-Oh; Suk, Kyung-Soo; Kim, Tae-Hwan; Lee, Hwan-Mo; Park, Moon-Soo; Lee, Seung-Hwan; Park, Sangun; Lee, Ju-Yeon; Ko, Su-Kyoung; Moon, Seong-Hwan

    2013-01-01

    Compared to an abundance of data on surgical techniques for degenerative spine conditions and the outcomes thereof, little is available to guide optimal perioperative pain management after spinal surgery. The aim of this study was to survey patterns of perioperative pain management after spinal surgery and to investigate the effects of perioperative pain management, such as pre-emptive analgesia and multi-modal postoperative pain management, on acute postoperative satisfaction, pain reduction, and health-related quality of life in patients undergoing spinal surgery. Non-blind multicenter prospective observational clinical series. Seventeen tertiary hospitals (14 hospitals attached to medical colleges and 3 general hospitals). Pain management protocols of 393 patients (153 men, 240 women; mean age of 67 years, ranging from 21 to 91 years) from 17 tertiary hospitals after spinal surgery for degenerative spine disease were evaluated using a self-administered questionnaire. A total of 79 (20%) patients received pre-emptive analgesics, which included cyclooxygenase-2 (COX-2) inhibitors, with or without administration of anticonvulsants, immediately before surgery at the time of antibiotic prophylaxis. Postoperative pain was managed mainly by multi-modal therapy (363 cases, 92%), along with various combinations of patient controlled anesthesia (PCA), conventional nonsteroidal anti-inflammatory drugs (NSAIDs), COX-2 inhibitors, and narcotics. Self-reported levels of pain were not significantly different among postoperative multiple modalities of pain management, but were different significantly for pre-emptive pain management regimens (P < 0.05, independent t-test). The number of patients that reported the self-administrative use of PCA was higher in the no pre-emptive pain management group compared to the pre-emptive group (P < 0.05). In regards to EQ-5D usual activity, depression/anxiety and self-care improved significantly in the pre-emptive pain management group when

  5. [Mild whole body hyperthermia in combination with inpatient multimodal oriented pain therapy: evaluation in patients with chronic unspecific lumbar back pain].

    PubMed

    Ettrich, U; Konrad, B; Prate, K; Seifert, J; Krummenauer, F

    2014-02-01

    A randomized controlled clinical trial was implemented to evaluate the effectiveness of combined mild hyperthermia therapy (body core temperature 38.4 °C) and multimodal inpatient rehabilitation for patients suffering from chronic low back pain when compared to multimodal pain therapy alone. A total of 88 patients were randomly assigned to the combined or single therapeutic schemes according to a block randomization scheme. According to the trial inclusion criteria all patients suffered from chronic low back pain and showed morphological degeneration. All patients underwent a 12-day inpatient multimodal pain therapy, which was complemented with a 6-session schedule of mild hyperthermia therapy for the intervention group (1 h at 38.6 °C). On admission and 3 months after treatment the study patients were asked to complete an interview assessment with the Oswestry low back pain disability questionnaire (Oswestry disability index). The change in the Oswestry disability index total score (%) 3 months after versus before therapy was defined as the primary clinical endpoint of the investigation. The patients in the control group and in the intervention group had a median age of 50 years. In the intervention group 70 % of the patients were female and 55 % reported having half to full time employment compared to 55 % and 43 % in the control group, respectively. On admission the control patients reported a median Oswestry disability index of 64 % and on recall the same of 64 %. The intervention group showed median Oswestry disability index estimates of 60 % and 66 %, respectively. The changes in the overall Oswestry disability index after 3 months differed significantly with an estimated 6 % for the intervention group versus 0 % for the control group (Wilcoxon p = 0.050). When combined with a multimodal inpatient lower back pain functional therapy in patients showing morphological degeneration, the mild hyperthermia therapy demonstrated

  6. Manual Therapy, Therapeutic Patient Education, and Therapeutic Exercise, an Effective Multimodal Treatment of Nonspecific Chronic Neck Pain: A Randomized Controlled Trial.

    PubMed

    Beltran-Alacreu, Hector; López-de-Uralde-Villanueva, Ibai; Fernández-Carnero, Josué; La Touche, Roy

    2015-10-01

    The aim of this study was to determine the effectiveness of a multimodal treatment in the short and medium term for disability in nonspecific chronic neck pain. The design of this study is a single-blinded randomized controlled trial carried out in a university research laboratory. Forty-five patients between 18 and 65 yrs with nonspecific chronic neck pain were included in this study. Each patient was treated eight times over a 4-wk period. The sample was divided into three groups: control group, subjected to a protocol of manual therapy; experimental group 1, subjected to a protocol of manual therapy and therapeutic patient education; and experimental group 2, subjected to manual therapy, therapeutic patient education, and a therapeutic exercise protocol. Assessments were performed at baseline and at 4, 8, and 16 wks using the following measurements: the Neck Disability Index, the 11-item Tampa Scale of Kinesiophobia, the Fear Avoidance Beliefs Questionnaire, the Neck Flexor Muscle Endurance Test, and the Visual Analog Fatigue Scale. The nonparametric Kruskal-Wallis test for the Neck Disability Index showed statistically significant differences between baseline outcomes and all follow-up periods (P < 0.01). In the Kruskal-Wallis test, differences were found for the Visual Analog Fatigue Scale and the Neck Flexor Muscle Endurance Test in the follow-ups at 8 and 16 wks (P < 0.05). Analysis of variance for group × time interaction showed statistically significant changes (Tampa Scale of Kinesiophobia, F = 3.613, P = 0.005; Fear Avoidance Beliefs Questionnaire, F = 2.803, P = 0.022). Minimal detectable changes were obtained in both experimental groups for the 11-item Tampa Scale of Kinesiophobia but not in the control group. Differences between experimental groups and the control group were found in the short and medium term. A multimodal treatment is a good method for reducing disability in patients with nonspecific chronic neck pain in the short and medium term.

  7. Low and therapeutic doses of antidepressants are associated with similar response in the context of multimodal treatment of pain.

    PubMed

    Bajwa, Zahid H; Simopoulos, Thomas T; Pal, Joshua; Kraemer, Jan J; Chopra, Pradeep; Nagda, Jyotsna V; Najib, Umer; Celestin, James; Sial, Khuram; Ahmad, Bilal; Warfield, Carol; Steinman, Theodore I; Wootton, Joshua

    2009-01-01

    Antidepressants are prescribed in a wide range of doses to treat both depression and chronic pain, with optimal psychopharmacology individualized for each patient. In the past decade more antidepressants from different chemical classes have become available and are being used for the treatment of both chronic pain and depression. To review the utilization pattern changes and compare response rates of different classes and doses of antidepressants for various pain conditions in the context of multimodal therapies. Chart review. We reviewed 5,916 records at an outpatient multidisciplinary pain center. Of these, 379 records were for patients diagnosed with cancer pain. Because the mechanisms and treatment approaches to cancer pain can differ greatly from non-cancer chronic pain, these records were excluded from the analysis. We assessed 1,506 medical records for patients with chronic non-caner pain who had used at least one antidepressant, with the main outcome measure being the Numeric Rating Pain Scale, 0-10. Of the 5,916 charts reviewed, 1,506 (25.4%) chronic non-cancer pain charts recorded the prescription of at least one antidepressant. Most patients received a combination of medications and procedures. Of the 450 patients receiving secondary amines, favorable responses were recorded for 340 (76%) patients, while 103 (23%) did not respond and 7 had unknown responses. Of the 492 patients receiving tertiary amines, favorable responses were recorded for 375 (76%) patients, while 113 (23%) did not respond, and 4 had unknown responses. Of the 533 patients receiving SSRI/SNRIs, favorable responses were recorded for 382 (72%) patients, while 147 (28%) did not respond, and 4 had unknown responses. Of the 369 patients receiving atypical antidepressants, favorable responses were recorded for 272 (74%) patients, while 94 (25%) did not respond, and 3 had unknown responses. A retrospective study design and the use of antidepressants as a part of multimodal treatment of pain

  8. Adding pregabalin to a multimodal analgesic regimen does not reduce pain scores following cosmetic surgery: a randomized trial.

    PubMed

    Chaparro, Luis Enrique; Clarke, Hance; Valdes, Paola A; Mira, Mauricio; Duque, Lorena; Mitsakakis, Nicholas

    2012-12-01

    Multimodal analgesia increases the chance of successful discharge and pain control after surgery, and pregabalin is being promoted as an effective analgesic, based on placebo-controlled studies. We investigated whether adding pregabalin improved pain control and reduced opioid requests when it was added to a multimodal analgesic regimen for cosmetic surgery. One hundred and ten women who underwent same-day cosmetic surgery were randomized to receive oral pregabalin, 75 mg q12 h for five consecutive days starting the night before surgery, or identical placebos. Participants, outcomes assessors, and the statistician were blinded. The primary outcome was postoperative numerical movement-evoked pain scores at 2, 24, 48, 72, and 96 h after surgery. The secondary outcomes included pain scores at rest; incidence of moderate to severe pain; and analgesic and antiemetic requirements; as well as the incidence of nausea, vomiting, and somnolence. Based on 99 patients who completed the study, we found no difference between the groups in the primary outcome; 72 h after surgery, movement-evoked median pain scores were <4/10 in both groups. We found no differences in opioid requirements (p = 0.95) or anti-inflammatory requirements (p = 0.45), and no difference in opioid-related adverse events. Perioperative pregabalin 75 mg twice a day does not increase benefit when it is added to an already multimodal analgesic regimen for patients undergoing cosmetic surgery. Several factors could explain our findings, including the possibility of publication bias in the current literature.

  9. Perception of multimodal cognitive treatment for people with chronic widespread pain--changing one's life plan.

    PubMed

    Bremander, Ann; Bergman, Stefan; Arvidsson, Barbro

    2009-01-01

    The aim of this study was to gain a deeper understanding of chronic widespread pain patients' perception of a multimodal treatment with a cognitive approach. A reformulated grounded theory study based on interviews with 16 participants in the programme was conducted at the end of a 6-month treatment period. The result describes a conceptual model of the informants' perception of the treatment. The core category 'changing one's life plan' comprised of three categories: 'changing one's perception of life', 'depending on support' and 'managing one's life'. Changing one's perception of life could be deep and overwhelming 'overall life changes' or more superficial 'life adjustments'. Support by health professionals and the patient group were of importance. At the end of the rehabilitation program managing one's life was perceived as either 'reorientation' or 'stagnation'. The informants who experienced overall life changes achieved reorientation with support by others, while those who experienced life adjustments did not change their way of managing one's life to any great extent. The core category changing one's life plan included the categories; changing one's perception of life, depending on support and managing one's life. Informants experiencing overall life changes were more likely to achieve reorientation than those who experienced life adjustments.

  10. Characteristics of response to experimental pain in sexually abused women.

    PubMed

    Granot, Michal; Somer, Eli; Zisman-Ilani, Yaara; Beny, Ahuva; Sadger, Ronit; Mirkin, Ronit; Moont, Ruth; Yovell, Yoram

    2011-09-01

    Women with a history of sexual abuse (SA) commonly report greater pain symptoms. It is still unclear whether enhanced pain susceptibility is the result of altered pain processing and response. Therefore, this pilot study aimed to explore pain sensitivity to experimentally induced pain and associated psychology in women with a history of severe SA. Twenty-one survivors of severe, long-lasting SA and 21 control women underwent experimentally induced heat pain and completed psychological questionnaires. Pain measures included heat pain thresholds, pain intensity ratings, and pain tolerance in response to contact heat, painful stimulation delivered to the volar forearm. Questionnaires included somatization (Brief Symptom Inventory), personality traits including harm avoidance, novelty seeking, and reward dependence (Cloninger tridimensional personality questionnaire), and levels of dissociation (Dissociative Experiences Scale). SA women had elevated heat pain thresholds (45.7±2.2°C vs. 43.9±3.1°C; P=0.042) and higher pain intensity ratings (on a 0 to 100 scale: 80.0±26.6 vs. 51.2±27.7; P=0.001). In addition, they had lower tolerability to painful tonic stimulation, greater somatization, and larger harm avoidance scores. Regression analyses showed that higher pain intensity ratings in SA women associated with greater tendency for harm avoidance but not with levels of dissociation. Women with a history of severe SA seem to have a paradoxical pattern of experimental pain response, characterized by both higher pain thresholds and increased pain intensity ratings. This pattern is associated with the personality trait of harm avoidance. Models that might account for these findings are discussed.

  11. [German Pain Questionnaire for Children, Adolescents and Parents (DSF-KJ). A multimodal questionnaire for diagnosis and treatment of children and adolescents suffering from chronic pain].

    PubMed

    Schroeder, S; Hechler, T; Denecke, H; Müller-Busch, M; Martin, A; Menke, A; Zernikow, B

    2010-02-01

    A multidimensional assessment of chronic pain is the most important tool for diagnosis and treatment. While the German Pain Questionnaire is routinely implemented in the treatment of adults with chronic pain, similar questionnaires are scarce for children and adolescents. It was the aim of the present study to report on the development and quality of a multimodal questionnaire assessing all relevant aspects of chronic pain in children and adolescents. The quality of the questionnaire was assessed (1) by implementing the questionnaire in a sample of children and adolescents suffering from chronic pain (aged 4-18 years), (2) by analysing missing items in the child, adolescent and parent version and (3) by analysing experts' ratings of the questionnaire. The German Pain Questionnaire for Children, Adolescents and Parents (DSF-KJ) was developed on the basis of the biopsychosocial model of chronic pain in experts' meetings. The DSF-KJ entails an assessment of sociodemographic variables, pain characteristics, triggering factors, previous pain treatment, pain-related disability and cognitive and emotional factors related to the pain experience. A total of 284 children and adolescents who presented for pain treatment in our tertiary institute completed the DSF-KJ. Eleven pain experts rated the questionnaire regarding its utility for diagnosis and treatment. With the use of the DSF-KJ, a detailed sample description was derived on the basis of the biopsychosocial model. More adolescent girls than boys presented to the institute. The majority of the children and adolescents suffered from headache and were severely affected by their chronic pain. Children and adolescents displayed similar pain characteristics. However, adolescents were more disabled due to chronic pain and had already undergone a variety of pain treatments. These differences may reflect an ongoing chronification in adolescents. Children, adolescents and their parents filled in the questionnaire thoroughly with

  12. Identifying prognostic factors predicting outcome in patients with chronic neck pain after multimodal treatment: A retrospective study.

    PubMed

    De Pauw, R; Kregel, J; De Blaiser, C; Van Akeleyen, J; Logghe, T; Danneels, L; Cagnie, B

    2015-08-01

    This study was conducted to identify possible prognostic factors to predict drop-out and favorable outcome in patients following a multimodal treatment program at an outpatient rehabilitation clinic. A retrospective cohort study was conducted on 437 patients with chronic neck pain involved in an exercise-based rehabilitation program of an outpatient rehabilitation center between January 2008 and November 2011. Prognostic factors were analyzed through a univariate and a multivariate logistic regression analysis. Multivariate logistic regression revealed that a higher age (OR=0.960), presence of headache (OR=0.436) or low back pain (OR=0.525), and having low levels of depression (OR=1.044) increase the odds to complete the multimodal treatment program. A high NDI-score (OR=0.945), a high NRS-score for pain in the upper extremities (OR=0.862), a low NRS score for pain in the neck (OR=1.372), and a trauma in the patient's history (OR=0.411) decrease the odds of having a favorable outcome after the given treatment program. It is important to assess these prognostic factors as they may help therapists to identify patients with a good prognosis or patients at risk. For those at risk, this would allow the treatment approach to be redirected to address their specific needs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The effect of a multimodal group programme in hospital workers with persistent low back pain: a prospective observational study.

    PubMed

    Pillastrini, P; Bonfiglioli, Roberta; Banchelli, F; Capra, F; Resende, Fernanda de Lima e Sa'; Villafane, J H; Vanti, Carla; Violante, F S

    2013-01-01

    Low Back Pain (LBP) is a very common disorder in hospital workers. Several studies examined the efficacy of multimodal interventions for health care providers suffering from LBP; nevertheless their results did not appear to be consistent. The aim of the study was to determine the effect of a multimodal group programme (MGP) on pain and disability in a sample of hospital workers with persistent LBP. A prospective cohort study was conducted to compare baseline measurements with changes over an eight-month period. The study focused on 109 workers suffering from persistent LBP with or without radiating pain. 62 nurses and 47 blue collars not involved in health care. The MGP consisted of six group sessions including supervised exercises, an at-home programme and ergonomic advice. The primary outcome measurement was the level of disability recorded with the Roland & Morris Disability Questionnaire, while the secondary outcome measurement was the evaluation of lumbar physical discomfort with the Visual Analogue Scale. Data were analyzed using the Multiple Imputation method for dropouts. At the short-term follow-up participants showed a statistically significant reduction (from baseline) of all outcome measurements, particularly for the nurses group. Moreover, about a third of the subjects showed clinically significant improvement. No significant reduction in pain and disability (from baseline) was observed at the mid-term follow-up in either group. An MGP dedicated to hospital workers seems to be partially useful only for short-term follow-up, particularly for health care providers.

  14. Pain-related emotions modulate experimental pain perception and autonomic responses.

    PubMed

    Rainville, Pierre; Bao, Quoc Viet Huynh; Chrétien, Pablo

    2005-12-05

    The effect of emotions on pain perception is generally recognized but the underlying mechanisms remain unclear. Here, emotions related to pain were induced in healthy volunteers using hypnosis, during 1-min immersions of the hand in painfully hot water. In Experiment 1, hypnotic suggestions were designed to induce various positive or negative emotions. Compared to a control condition with hypnotic-relaxation, negative emotions produced robust increases in pain. In Experiment 2, induction of pain-related anger and sadness were found to increase pain. Pain increases were associated with increases in self-rated desire for relief and decreases in expectation of relief, and with increases in arousal, negative affective valence and decreases in perceived control. In Experiment 3, hypnotic suggestions specifically designed to increase and decrease the desire for relief produced increases and decreases in pain, respectively. In all three experiments, emotion-induced changes in pain were most consistently found on ratings of pain unpleasantness compared to pain intensity. Changes in pain-evoked cardiac responses (R-R interval decrease), measured in experiments 2 and 3, were consistent with changes in pain unpleasantness. Correlation and multiple regression analyses suggest that negative emotions and desire for relief influence primarily pain affect and that pain-evoked autonomic responses are strongly associated with pain affect. These results confirm the hypothesized influence of the desire for relief on pain perception, and particularly on pain affect, and support the functional relation between pain affect and autonomic nociceptive responses. This study provides further experimental confirmation that pain-related emotions influence pain perception and pain-related physiological responses.

  15. [Patient perspectives in outcome research : Development of a focus group concept for collating patient perspectives on determination of effectiveness of multimodal pain therapy - A pilot study].

    PubMed

    Neustadt, K; Deckert, S; Heineck, R; Kopkow, C; Preißler, A; Sabatowski, R; Schmitt, J; Kaiser, U

    2017-04-01

    To assess the efficacy of multimodal pain therapy for chronic pain patients it is necessary to use suitable outcome domains as well as reliable and valid measurement instruments. Using pain intensity as an example, however, it is shown that there are critical issues with respect to suitability for chronic pain patients and the quality (e.g. content validity, feasibility and interpretability) of commonly used measurement instruments. A focus group concept was designed to discuss the construct of pain intensity and common measurement instruments with chronic pain patients who underwent multimodal pain therapy. The focus group concept was tested in two pilot groups (N = 10) where eight issues previously established in guidelines were discussed. The results of the pilot studies affirmed that the construct of pain intensity as well as the measurement instruments must be critically considered when applied to chronic pain patients and the effectiveness of multimodal pain therapy. The concept of patient focus groups proved to be a suitable method for patient participation. Integrating patients should be considered not only in discussions of existing pain scales but also in developing new measurement instruments.

  16. Registration of multimodal brain images: some experimental results

    NASA Astrophysics Data System (ADS)

    Chen, Hua-mei; Varshney, Pramod K.

    2002-03-01

    Joint histogram of two images is required to uniquely determine the mutual information between the two images. It has been pointed out that, under certain conditions, existing joint histogram estimation algorithms like partial volume interpolation (PVI) and linear interpolation may result in different types of artifact patterns in the MI based registration function by introducing spurious maxima. As a result, the artifacts may hamper the global optimization process and limit registration accuracy. In this paper we present an extensive study of interpolation-induced artifacts using simulated brain images and show that similar artifact patterns also exist when other intensity interpolation algorithms like cubic convolution interpolation and cubic B-spline interpolation are used. A new joint histogram estimation scheme named generalized partial volume estimation (GPVE) is proposed to eliminate the artifacts. A kernel function is involved in the proposed scheme and when the 1st order B-spline is chosen as the kernel function, it is equivalent to the PVI. A clinical brain image database furnished by Vanderbilt University is used to compare the accuracy of our algorithm with that of PVI. Our experimental results show that the use of higher order kernels can effectively remove the artifacts and, in cases when MI based registration result suffers from the artifacts, registration accuracy can be improved significantly.

  17. Comparison of 2 Multimodal Interventions With and Without Whole Body Vibration Therapy Plus Traction on Pain and Disability in Patients With Nonspecific Chronic Low Back Pain.

    PubMed

    Maddalozzo, Gianni F; Kuo, Brian; Maddalozzo, Walker A; Maddalozzo, Conner D; Galver, Johnny W

    2016-12-01

    The purpose of this secondary data analysis was to compare the effect of 2 multimodal exercise-based physical therapy interventions (one with and one without whole-body vibration [WBV] therapy plus traction) on pain and disability in patients with nonspecific chronic low back pain (NSCLBP). We conducted a secondary analysis of data from 2 distinct samples. One sample was from the Focus on Therapeutic Outcomes Inc. (FOTO) group (n = 55, age 55.1 ± 19.0 years), and the other was the Illinois Back Institute (IBI) (n = 70, age 47.5 ± 13.4 years). Both groups of patients had NSCLBP for more than 3 months and a pain numeric rating scale (NRS) score of ≥7. Both groups received treatment consisting of flexibility or stretching exercises, core stability training, functional training, and postural exercises and strengthening exercises. However, the IBI group also received WBV plus traction. NSCLBP was measured before and after therapeutic trials using the NRS for pain and Oswestry Disability Index (ODI). The NRS scores were significantly improved in both groups, decreasing by 2 points in the FOTO group and by 5 points in the IBI group. The ODI scores were significantly improved in both groups; the FOTO group score improved by 9 points and the IBI group improved by 22 points. The results of this preliminary study suggest that NPS and ODI scores statistically improved for both NSCLBP groups receiving multimodal care. However, the group that included WBV therapy plus traction in combination with multimodal care had greater clinical results. This study had several limitations making it difficult to generalize the results from this study sample to the entire population.

  18. Meta-analysis on brain representation of experimental dental pain.

    PubMed

    Lin, C-S; Niddam, D M; Hsu, M-L

    2014-02-01

    Functional magnetic resonance imaging (fMRI) has been widely used for investigating the brain representation associated with dental pain evoked by pulpal electrical stimulation. However, because of the heterogeneity of experimental designs and the small sample size of individual studies, the common brain representation regarding dental pain has remained elusive. We used imaging meta-analysis to investigate six dental pain-related fMRI studies (n = 87) and tested 3 hypotheses: (1) Dental pain is associated with the 'core' pain-related network; (2) pain-related brain activation is somatotopically organized in the somatosensory cortex; and (3) dental pain is associated with the cognitive-affective network related to pain. Qualitative and quantitative meta-analyses revealed: (1) common activation of the core pain-related network, including the somatosensory cortex, the insula, and the cingulate cortex; (2) inconsistency in somatotopically organized activation of the primary somatosensory cortex; and (3) common activation in the dorsolateral prefrontal cortex, suggesting a role of re-appraisal and coping in the experience of dental pain. In conclusion, fMRI combined with pulpal stimulation can effectively evoke activity in the pain-related network. The dental pain-related brain representation disclosed the mechanisms of how sensory and cognitive-affective factors shape dental pain, which will help in the development of more effective customized methods for central pain control.

  19. Imaging of nontraumatic acute hip pain in children: multimodality approach with attention to the reduction of medical radiation exposure.

    PubMed

    Sarwar, Zahir U; DeFlorio, Robert; Catanzano, Tara M

    2014-08-01

    Nontraumatic acute hip pain in children is common. However, the presentation and etiology is variable, including difficulty with weight bearing and abnormal gait. Barriers in communication, multiple possible etiologies, and age-specific anatomical variations of the pediatric hip make the evaluation of hip pain in children a difficult clinical diagnosis. Multimodality radiologic approach plays an important role for the evaluation of these children. However, owing to the complexity of pediatric hip disease, children sometimes undergo multiple radiologic examinations, resulting in delay in diagnosis and increased radiation dose. This article focuses on the illustration and discussion of common causes of acute hip pain or limp in children. Current recommendations for the imaging of these patients with specific attention to the ALARA (as low radiation as reasonably achievable) principle of radiation exposure are considered. Examples of the entities discussed are provided. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. A multimodal approach to management of suspected neuropathic pain in a prairie falcon (Falco mexicanus).

    PubMed

    Shaver, Stephanie L; Robinson, Narda G; Wright, Bonnie D; Kratz, Gail E; Johnston, Matthew S

    2009-09-01

    An adult male prairie falcon (Falco mexicanus) was presented for evaluation and treatment of self-inflicted wounds along the right proximal patagium. The bird had started self-traumatizing approximately 1 month after fracturing the right metacarpus, although the fracture had stabilized, surface wounds had healed completely, and treatment with a nonsteroidal antiinflammatory drug had been administered. The bird was treated with gabapentin (11 mg/kg p.o. q12h), ketamine (0.5 mg/kg i.m. q24h), and low level laser therapy (LLLT) (<5 mW, 630-680 nm, 5-second application per site) for 3 weeks, but, despite initial improvement, new self-inflicted wounds appeared at the same site. Approximately 1.5 months later, a radial and medianoulnar nerve block was performed by using bupivacaine (2 mg/kg) and medetomidine (0.5 microg/kg). In addition, the dosing interval of ketamine was increased to q12h, and the dose of gabapentin was increased 7.5-fold. A higher energy and wavelength of LLLT (1040 mW, 830 nm, 2 J/cm2) was applied once to the injured region and fracture site, then the original LLLT protocol was applied once daily. After 2.5 months, the wounds healed completely and no further mutilation took place. Once deemed ready for release, the falcon was returned to the wild after 181 days in captivity. This is the first reported application of successful multimodal analgesia in a raptor with uncontrolled neuropathic pain.

  1. Inclusion of trigger point dry needling in a multimodal physical therapy program for postoperative shoulder pain: a randomized clinical trial.

    PubMed

    Arias-Buría, José L; Valero-Alcaide, Raquel; Cleland, Joshua Aland; Salom-Moreno, Jaime; Ortega-Santiago, Ricardo; Atín-Arratibel, María A; Fernández-de-las-Peñas, César

    2015-01-01

    The purpose of this study was to evaluate the effects of including 1 session of trigger point dry needling (TrP-DN) into a multimodal physiotherapy treatment on pain and function in postoperative shoulder pain. Twenty patients (5 male; 15 female; age, 58 ± 12 years) with postoperative shoulder pain after either open reduction and internal fixation with Proximal Humeral Internal Locking System plate plate or rotator cuff tear repair were randomly divided into 2 groups: physiotherapy group (n = 10) who received best evidence physical therapy interventions and a physical therapy plus TrP-DN group (n = 10) who received the same intervention plus a single session of TrP-DN targeted at active TrPs. The Constant-Murley score was used to determine pain, activities of daily living, range of motion, and strength, which was captured at baseline and 1 week after by an assessor blinded to group assignment. Analysis of variance showed that subjects receiving TrP-DN plus physical therapy exhibited greater improvement in the Constant-Murley total score (P < .001) and also activities of daily living (P < .001) and strength (P = .019) subscales than those receiving physical therapy alone. Between-group effect sizes were large in favor of the TrP-DN group (0.97 < SMD < 1.45). Both groups experienced similar improvements in pain (P < .001) and range of motion (P < .001). Our results suggest that including a single session of TrP-DN in the first week of a multimodal physical therapy approach may assist with faster increases in function in individuals with postoperative shoulder pain. Copyright © 2015 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  2. Multimodal therapy for category III chronic prostatitis/chronic pelvic pain syndrome in UPOINTS phenotyped patients

    PubMed Central

    MAGRI, VITTORIO; MARRAS, EMANUELA; RESTELLI, ANTONELLA; WAGENLEHNER, FLORIAN M.E.; PERLETTI, GIANPAOLO

    2015-01-01

    The complex network of etiological factors, signals and tissue responses involved in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) cannot be successfully targeted by a single therapeutic agent. Multimodal approaches to the therapy of CP/CPPS have been and are currently being tested, as in the frame of complex diagnostic-therapeutic phenotypic approaches such as the urinary, psychosocial, organ-specific, infection, neurological and muscle tenderness (UPOINTS) system. In this study, the effect of combination therapy on 914 patients diagnosed, phenotyped and treated in a single specialized prostatitis clinic was analyzed. Patients received α-blockers, Serenoa repens (S. repens) extracts combined or not with supplements (lycopene and selenium) and, in the presence of documented or highly suspected infection, antibacterial agents. Combination treatment induced marked and significant improvements of National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) prostatitis symptom scores, International Index of Erectile Function (IIEF) sexual dysfunction scores, urinary peak flow rates and bladder voiding efficiency. These improvements, assessed after a 6-month course of therapy, were sustained throughout a follow-up period of 18 months. A clinically appreciable reduction of ≥6 points of the total NIH-CPSI score was achieved in 77.5% of patients subjected to combination therapy for a period of 6 months. When the patients were divided in two cohorts, depending on the diagnosis of CP/CPPS [inflammatory (IIIa) vs. non-inflammatory (IIIb) subtypes], significant improvements of all signs and symptoms of the syndrome were observed in both cohorts at the end of therapy. Intergroup comparison showed that patients affected by the IIIa sub-category of CP/CPPS showed more severe signs and symptoms (NIH-CPSI total, pain and quality of life impact scores, and Qmax) at baseline when compared with IIIb patients. However, the improvement of symptoms after

  3. Multimodal therapy for category III chronic prostatitis/chronic pelvic pain syndrome in UPOINTS phenotyped patients.

    PubMed

    Magri, Vittorio; Marras, Emanuela; Restelli, Antonella; Wagenlehner, Florian M E; Perletti, Gianpaolo

    2015-03-01

    The complex network of etiological factors, signals and tissue responses involved in chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) cannot be successfully targeted by a single therapeutic agent. Multimodal approaches to the therapy of CP/CPPS have been and are currently being tested, as in the frame of complex diagnostic-therapeutic phenotypic approaches such as the urinary, psychosocial, organ-specific, infection, neurological and muscle tenderness (UPOINTS) system. In this study, the effect of combination therapy on 914 patients diagnosed, phenotyped and treated in a single specialized prostatitis clinic was analyzed. Patients received α-blockers, Serenoa repens (S. repens) extracts combined or not with supplements (lycopene and selenium) and, in the presence of documented or highly suspected infection, antibacterial agents. Combination treatment induced marked and significant improvements of National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) prostatitis symptom scores, International Index of Erectile Function (IIEF) sexual dysfunction scores, urinary peak flow rates and bladder voiding efficiency. These improvements, assessed after a 6-month course of therapy, were sustained throughout a follow-up period of 18 months. A clinically appreciable reduction of ≥6 points of the total NIH-CPSI score was achieved in 77.5% of patients subjected to combination therapy for a period of 6 months. When the patients were divided in two cohorts, depending on the diagnosis of CP/CPPS [inflammatory (IIIa) vs. non-inflammatory (IIIb) subtypes], significant improvements of all signs and symptoms of the syndrome were observed in both cohorts at the end of therapy. Intergroup comparison showed that patients affected by the IIIa sub-category of CP/CPPS showed more severe signs and symptoms (NIH-CPSI total, pain and quality of life impact scores, and Qmax) at baseline when compared with IIIb patients. However, the improvement of symptoms after

  4. A Randomized Controlled Trial Comparing Two Multimodal Analgesic Techniques in Patients Predicted to Have Severe Pain After Cesarean Delivery.

    PubMed

    Booth, Jessica L; Harris, Lynnette C; Eisenach, James C; Pan, Peter H

    2016-04-01

    .99). Adding a higher dose of intrathecal morphine and oral acetaminophen to a multimodal pain regimen in patients predicted to be at risk for high acute postpartum pain after cesarean delivery results in a significant reduction of acute postoperative pain scores at 24 hours.

  5. Associations between psychological variables and pain in experimental pain models. A systematic review.

    PubMed

    Hansen, M S; Horjales-Araujo, E; Dahl, J B

    2015-10-01

    The association between pain and psychological characteristics has been widely debated. Thus, it remains unclear whether an individual's psychological profile influences a particular pain experience, or if previous pain experience contributes to a certain psychological profile. Translational studies performed in healthy volunteers may provide knowledge concerning psychological factors in healthy individuals as well as basic pain physiology. The aim of this review was to investigate whether psychological vulnerability or specific psychological variables in healthy volunteers are predictive of the level of pain following experimental pain models. A systematic search on the databases, PubMed, Embase, Cochcrane library, and Clinicaltrials.gov was performed during September 2014. All trials investigating the association between psychological variables and experimental pain in healthy volunteers were considered for inclusion. Twenty-nine trials met the inclusion criteria, with a total of 2637 healthy volunteers. The included trials investigated a total of 45 different psychological tests and 27 different types of pain models. The retrieved trials did not present a sufficiently homogenous group to perform meta-analysis. The collected results were diverse. A total of 16 trials suggested that psychological factors may predict the level of pain, seven studies found divergent results, and six studies found no significant association between psychological variables and experimental pain. Psychological factors may have predictive value when investigating experimental pain. However, due to substantial heterogeneity and methodological shortcomings of the published literature, firm conclusions are not possible. © 2015 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  6. Spontaneous Chronic Pain After Experimental Thoracotomy Revealed by Conditioned Place Preference: Morphine Differentiates Tactile Evoked Pain From Spontaneous Pain.

    PubMed

    Hung, Ching-Hsia; Wang, Jeffrey Chi-Fei; Strichartz, Gary R

    2015-09-01

    Chronic pain after surgery limits social activity, interferes with work, and causes emotional suffering. A major component of such pain is reported as resting or spontaneous pain with no apparent external stimulus. Although experimental animal models can simulate the stimulus-evoked chronic pain that occurs after surgery, there have been no studies of spontaneous chronic pain in such models. Here the conditioned place preference (CPP) paradigm was used to reveal resting pain after experimental thoracotomy. Male Sprague Dawley rats received a thoracotomy with 1-hour rib retraction, resulting in evoked tactile hypersensitivity, previously shown to last for at least 9 weeks. Intraperitoneal injections of morphine (2.5 mg/kg) or gabapentin (40 mg/kg) gave equivalent 2- to 3-hour-long relief of tactile hypersensitivity when tested 12 to 14 days postoperatively. In separate experiments, single trial CPP was conducted 1 week before thoracotomy and then 12 days (gabapentin) or 14 days (morphine) after surgery, followed the next day by 1 conditioning session with morphine or gabapentin, both versus saline. The gabapentin-conditioned but not the morphine-conditioned rats showed a significant preference for the analgesia-paired chamber, despite the equivalent effect of the 2 agents in relieving tactile allodynia. These results show that experimental thoracotomy in rats causes spontaneous pain and that some analgesics, such as morphine, that reduce evoked pain do not also relieve resting pain, suggesting that pathophysiological mechanisms differ between these 2 aspects of long-term postoperative pain. Perspective: Spontaneous pain, a hallmark of chronic postoperative pain, is demonstrated here in a rat model of experimental postthoracotomy pain, further validating the use of this model for the development of analgesics to treat such symptoms. Although stimulus-evoked pain was sensitive to systemic morphine, spontaneous pain was not, suggesting different mechanistic

  7. An Innovative and Portable Multimodal Pain Relief Device for the Management of Neuropathic Low Back Pain - a Study from Kashmir (Southeast Asia).

    PubMed

    Tarfarosh, Shah Faisal Ahmad; Lone, Baseer-Ul-Rasool; Beigh, Mirza-Idrees-Ul-Haq; Manzoor, Mushbiq

    2016-06-29

    We developed a portable multimodal system with seven different mechanisms of pain relief incorporated into a lumbar belt called the Comfort-N-Harmony Belt (C&H belt). Here, we describe the technical details of the system and also summarize the effects of this multimodal pain relieving technology as an adjuvant to analgesics versus analgesics alone, on the level of pain, improvement of psychological status, disability, and the quality of life in the patients with neuropathic low back pain (LBP). We tracked the volunteers who were following up at a tertiary health care center for the complaints of neuropathic LBP of minimum three months duration and were on analgesics alone with no relief in the severity of the pain. Study group A (n = 45) consisted of volunteers with LBP on C&H belt therapy, along with the usually prescribed analgesic intake, and group B (n = 45) with LBP volunteers on analgesics, plus a similar looking but plain leather belt (placebo). For pain, the VAS (Visual Analogue Scale); for anxiety and depression, the (HADS) Hospital Anxiety-Depression Scale; for disability, the RMDQ (Roland Morris Disability Questionnaire); and for quality of life, (NHP) Nottingham-Health-Profile were used before and after the study period.  There were no significant differences in demographic variables between the groups (p < 0.05). After the study period of one month, VAS, RMDQ, NHP-pain, NHP-physical activity, and HADS scores in both groups were significantly improved compared to the pre-treatment scores (p < 0.05). Group A also showed significant improvements in the scores of NHP-energy level and NHP-social isolation (p < 0.05). The post-treatment scores did not significantly show any difference between the two groups (p > 0.05). However, in comparison of pre- and post-treatment scores, the pre-treatment score values of RMDQ, NHP-pain, NHP-physical activity, and NHP-social isolation were much higher in group A compared to the group B, but still these scores were

  8. An Innovative and Portable Multimodal Pain Relief Device for the Management of Neuropathic Low Back Pain - a Study from Kashmir (Southeast Asia)

    PubMed Central

    Lone, Baseer-ul-Rasool; Beigh, Mirza-Idrees-ul-Haq; Manzoor, Mushbiq

    2016-01-01

    We developed a portable multimodal system with seven different mechanisms of pain relief incorporated into a lumbar belt called the Comfort-N-Harmony Belt (C&H belt). Here, we describe the technical details of the system and also summarize the effects of this multimodal pain relieving technology as an adjuvant to analgesics versus analgesics alone, on the level of pain, improvement of psychological status, disability, and the quality of life in the patients with neuropathic low back pain (LBP). We tracked the volunteers who were following up at a tertiary health care center for the complaints of neuropathic LBP of minimum three months duration and were on analgesics alone with no relief in the severity of the pain. Study group A (n = 45) consisted of volunteers with LBP on C&H belt therapy, along with the usually prescribed analgesic intake, and group B (n = 45) with LBP volunteers on analgesics, plus a similar looking but plain leather belt (placebo). For pain, the VAS (Visual Analogue Scale); for anxiety and depression, the (HADS) Hospital Anxiety-Depression Scale; for disability, the RMDQ (Roland Morris Disability Questionnaire); and for quality of life, (NHP) Nottingham-Health-Profile were used before and after the study period.  There were no significant differences in demographic variables between the groups (p < 0.05). After the study period of one month, VAS, RMDQ, NHP-pain, NHP-physical activity, and HADS scores in both groups were significantly improved compared to the pre-treatment scores (p < 0.05). Group A also showed significant improvements in the scores of NHP-energy level and NHP-social isolation (p < 0.05). The post-treatment scores did not significantly show any difference between the two groups (p > 0.05). However, in comparison of pre- and post-treatment scores, the pre-treatment score values of RMDQ, NHP-pain, NHP-physical activity, and NHP-social isolation were much higher in group A compared to the group B, but still these scores were

  9. Amantadine sulfate reduces experimental sensitization and pain in chronic back pain patients.

    PubMed

    Kleinböhl, Dieter; Görtelmeyer, Roman; Bender, Hans-Joachim; Hölzl, Rupert

    2006-03-01

    We investigated if established psychophysical measures of enhanced experimental sensitization in chronic musculoskeletal pain can be reduced by adjuvant treatment with a N-methyl-d-aspartate receptor antagonist, amantadine sulfate, and whether a reduction in sensitization might be accompanied by a concurrent improvement in clinical pain. Sensitization was evaluated by an experimental tonic heat model of short-term sensitization with concurrent subjective and behavioral psychophysical scaling. Twenty-six patients with chronic back pain were included in the randomized, double-blind, placebo-controlled study and received daily dosages of either placebo or 100 mg of amantadine sulfate during a 1-wk treatment. Participants completed quantitative sensory testing of pain thresholds and experimental sensitization before and after treatment and clinical pain ratings before, during, and after treatment. Experimental sensitization and clinical pain were reduced in patients receiving verum. Initially, experimental sensitization was enhanced in patients, with early sensitization at nonpainful intensities of contact heat and enhanced sensitization at painful intensities, as shown previously. After 1 wk of treatment, experimental sensitization was reduced with amantadine sulfate but not with placebo. We conclude that adjuvant chronic pain treatment with N-methyl-d-aspartate receptor antagonists might be beneficial for chronic pain if enhanced sensitization is involved and that the quantitative sensory test of temporal summation may be used to verify this.

  10. The influence of experimentally induced pain on shoulder muscle activity.

    PubMed

    Diederichsen, Louise Pyndt; Winther, Annika; Dyhre-Poulsen, Poul; Krogsgaard, Michael R; Nørregaard, Jesper

    2009-04-01

    Muscle function is altered in painful shoulder conditions. However, the influence of shoulder pain on muscle coordination of the shoulder has not been fully clarified. The aim of the present study was to examine the effect of experimentally induced shoulder pain on shoulder muscle function. Eleven healthy men (range 22-27 years), with no history of shoulder or cervical problems, were included in the study. Pain was induced by 5% hypertonic saline injections into the supraspinatus muscle or subacromially. Seated in a shoulder machine, subjects performed standardized concentric abduction (0 degrees -105 degrees) at a speed of approximately 120 degrees/s, controlled by a metronome. During abduction, electromyographic (EMG) activity was recorded by intramuscular wire electrodes inserted in two deeply located shoulder muscles and by surface-electrodes over six superficially located shoulder muscles. EMG was recorded before pain, during pain and after pain had subsided and pain intensity was continuously scored on a visual analog scale (VAS). During abduction, experimentally induced pain in the supraspinatus muscle caused a significant decrease in activity of the anterior deltoid, upper trapezius and the infraspinatus and an increase in activity of lower trapezius and latissimus dorsi muscles. Following subacromial injection a significantly increased muscle activity was seen in the lower trapezius, the serratus anterior and the latissimus dorsi muscles. In conclusion, this study shows that acute pain both subacromially and in the supraspinatus muscle modulates coordination of the shoulder muscles during voluntary movements. During painful conditions, an increased activity was detected in the antagonist (latissimus), which support the idea that localized pain affects muscle activation in a way that protects the painful structure. Further, the changes in muscle activity following subacromial pain induction tend to expand the subacromial space and thereby decrease the load

  11. Heritability of Pain Catastrophizing and Associations with Experimental Pain Outcomes: A Twin Study

    PubMed Central

    Trost, Zina; Strachan, Eric; Sullivan, Michael; Vervoort, Tine; Avery, Ally R.; Afari, Niloofar

    2014-01-01

    The current study employed a twin paradigm to examine the genetic and environmental contributions to pain catastrophizing as well as the observed association between pain catastrophizing and cold pressor task (CPT) outcomes. Male and female monozygotic (n=206) and dizygotic twins (n=194) from the University of Washington Twin Registry completed a measure of pain catastrophizing and performed a CPT challenge. As expected, pain catastrophizing emerged as a significant predictor of several CPT outcomes, including cold pressor immersion tolerance, pain tolerance, and delayed pain rating. The heritability estimate for pain catastrophizing was found to be 37% with the remaining 63% of variance attributable to unique environmental influence. Additionally, the observed associations between pain catastrophizing and CPT outcomes were not found attributable to shared genetics or environmental exposure, suggesting a direct relationship between catastrophizing and experimental pain outcomes. This study is the first to examine the heritability of pain catastrophizing and potential processes by which pain catastrophizing is related to experimental pain response. PMID:25599234

  12. Experimental neck muscle pain impairs standing balance in humans.

    PubMed

    Vuillerme, Nicolas; Pinsault, Nicolas

    2009-02-01

    Impaired postural control has been reported in patients with chronic neck pain of both traumatic and non-traumatic etiologies, but whether painful stimulation of neck muscle per se can affect balance control during quiet standing in humans remains unclear. The purpose of the present experiment was thus to investigate the effect of experimental neck muscle pain on standing balance in young healthy adults. To achieve this goal, 16 male university students were asked to stand upright as still as possible on a force platform with their eyes closed in two conditions of No pain and Pain of the neck muscles elicited by experimental painful electrical stimulation. Postural control and postural performance were assessed by the displacements of the center of foot pressure (CoP) and of the center of mass (CoM), respectively. The results showed increased CoP and CoM displacements variance, range, mean velocity, and mean and median frequencies in the Pain relative to the No pain condition. The present findings emphasize the destabilizing effect of experimental neck muscle pain per se, and more largely stress the importance of intact neck neuromuscular function on standing balance.

  13. Verbally reinforcing pain reports: an experimental test of the operant model of chronic pain.

    PubMed

    Jolliffe, Christopher D; Nicholas, Michael K

    2004-01-01

    Effective treatments for chronic pain have been based on the operant model for chronic pain, which holds that pain behaviours can be operantly controlled by various reinforcers. Support for the operant model comes primarily from treatment/outcome studies which report significant reductions in pain behaviours in chronic pain patients, but fail to demonstrate the underlying operant thesis that various reinforcers play a significant role in the establishment and maintenance of pain behaviours. In an experimental test of this hypothesis, the pain reports of forty-six healthy undergraduate students were measured over two sets of fifteen trials, in which the pressure from a blood-pressure cuff applied to their arm either remained stable or decreased over time. Half of the subjects received positive verbal reinforcement from the experimenter after each trial if their report of pain intensity exceeded that of the previous trial. Overall, the mean pain reports of reinforced subjects were significantly greater than those of the non-reinforced subjects both when the intensity of the cuff was stable over trials, and when it decreased, as expected. These results provide support for the operant model of chronic pain. The clinical and theoretical implications of these results for the operant model of chronic pain are discussed, and suggestions for future research are made.

  14. Pain referral and regional deep tissue hyperalgesia in experimental human hip pain models.

    PubMed

    Izumi, Masashi; Petersen, Kristian Kjær; Arendt-Nielsen, Lars; Graven-Nielsen, Thomas

    2014-04-01

    Hip disorder patients typically present with extensive pain referral and hyperalgesia. To better understand underlying mechanisms, an experimental hip pain model was established in which pain referrals and hyperalgesia could be studied under standardized conditions. In 16 healthy subjects, pain was induced by hypertonic saline injection into the gluteus medius tendon (GMT), adductor longus tendon (ALT), or gluteus medius muscle (GMM). Isotonic saline was injected contralaterally as control. Pain intensity was assessed on a visual analogue scale (VAS), and subjects mapped the pain distribution. Before, during, and after injections, passive hip joint pain provocation tests were completed, together with quantitative sensory testing as follows: pressure pain thresholds (PPTs), cuff algometry pain thresholds (cuff PPTs), cutaneous pin-prick sensitivity, and thermal pain thresholds. Hypertonic saline injected into the GMT resulted in higher VAS scores than hypertonic injections into the ALT and GMM (P<.05). Referred pain areas spread to larger parts of the leg after GMT and GMM injections compared with more regionalized pain pattern after ALT injections (P<.05). PPTs at the injection site were decreased after hypertonic saline injections into GMT and GMM compared with baseline, ALT injections, and isotonic saline. Cuff PPTs from the thigh were decreased after hypertonic saline injections into the ALT compared with baseline, GMT injections, and isotonic saline (P<.05). More subjects had positive joint pain provocation tests after hypertonic compared with isotonic saline injections (P<.05), indicating that this provocation test also assessed hyperalgesia in extra-articular soft tissues. The experimental models may open for better understanding of pain mechanisms associated with painful hip disorders.

  15. The genetic influences on oxycodone response characteristics in human experimental pain.

    PubMed

    Olesen, Anne E; Sato, Hiroe; Nielsen, Lecia M; Staahl, Camilla; Droney, Joanne; Gretton, Sophy; Branford, Ruth; Drewes, Asbjørn M; Arendt-Nielsen, Lars; Riley, Julia; Ross, Joy

    2015-08-01

    Human experimental pain studies are of value to study basic pain mechanisms under controlled conditions. The aim of this study was to investigate whether genetic variation across selected mu-, kappa- and delta-opioid receptor genes (OPRM1, OPRK1and OPRD1, respectively) influenced analgesic response to oxycodone in healthy volunteers. Experimental multimodal, multitissue pain data from previously published studies carried out in Caucasian volunteers were used. Data on thermal skin pain tolerance threshold (PTT) (n = 37), muscle pressure PTT (n = 31), mechanical visceral PTT (n = 43) and thermal visceral PTT (n = 41) were included. Genetic associations with pain outcomes were explored. Nineteen opioid receptor genetic polymorphisms were included in this study. Variability in oxycodone response to skin heat was associated with OPRM1 single-nucleotide polymorphisms (SNPs) rs589046 (P < 0.0001) and rs563649 (P < 0.0001). Variability in oxycodone response to visceral pressure was associated with four OPRM1 SNPs: rs589046 (P = 0.015), rs1799971 (P = 0.045), rs9479757 (P = 0.009) and rs533586 (P = 0.046). OPRM1 SNPs were not associated with oxycodone visceral heat threshold, however, one OPRD1 rs419335 reached significance (P = 0.015). Another OPRD1 SNP rs2234918 (P = 0.041) was associated with muscle pressure. There were no associations with OPRK1 SNPs and oxycodone response for any of the pain modalities. Associations were found between analgesic effects of oxycodone and OPRM1 and OPRD1 SNPs; therefore, variation in opioid receptor genes may partly explain responder characteristics to oxycodone.

  16. Phenotypically directed multimodal therapy for chronic prostatitis/chronic pelvic pain syndrome: a prospective study using UPOINT.

    PubMed

    Shoskes, Daniel A; Nickel, J Curtis; Kattan, Michael W

    2010-06-01

    Large, controlled trials in chronic pelvic pain syndrome (CPPS) have failed due to patient heterogeneity. To phenotype CPPS patients, we developed the UPOINT system with 6 domains (Urinary, Psychosocial, Organ-Specific, Infection, Neurologic/Systemic and Tenderness). In this study, we treated patients with multimodal therapy based on the UPOINT phenotype and measured response after at least 6 months. Patients with CPPS were offered multimodal therapy based on the UPOINT phenotype (eg, Urinary: alpha blocker or antimuscarinic; Organ-specific: quercetin; Tenderness: physical therapy). One hundred patients agreed to therapy and were reexamined after 26 weeks. Primary endpoint was a minimum 6-point drop in NIH-Chronic Prostatitis Symptom Index (CPSI). Mean age was 46 years, and median symptom duration was 24 months. A median of 3 UPOINT domains were positive, the most common being Organ-specific (70%), Tenderness (64%), and Urinary (59%). With a median 50-week follow-up, 84% had at least a 6-point fall in CPSI. Number of domains and initial CPSI did not predict response. Mean changes (+/-SD) for CPSI subscores were pain 11.5+/-3.2 to 6.1+/-3.9, urine 4.7+/-3.1 to 2.6+/-2.0, QOL 9.1+/-2.3 to 4.5+/-2.8, and total 25.2+/-6.1 to 13.2+/-7.2 (all P<.0001). No domain predicted outcome; however, quercetin use resulted in a greater CPSI decrease. Multimodal therapy using UPOINT leads to significant improvement in symptoms and quality of life. Moreover, a placebo-controlled trial for every therapy combination is not feasible, and results using UPOINT compare favorably with all large trials of monotherapy. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  17. The effect of experimentally-induced subacromial pain on proprioception.

    PubMed

    Sole, Gisela; Osborne, Hamish; Wassinger, Craig

    2015-02-01

    Shoulder injuries may be associated with proprioceptive deficits, however, it is unknown whether these changes are due to the experience of pain, tissue damage, or a combination of these. The aim of this study was to investigate the effect of experimentally-induced sub-acromial pain on proprioceptive variables. Sub-acromial pain was induced via hypertonic saline injection in 20 healthy participants. Passive joint replication (PJR) and threshold to detection of movement direction (TTDMD) were assessed with a Biodex System 3 Pro isokinetic dynamometer for baseline control, experimental pain and recovery control conditions with a starting position of 60° shoulder abduction. The target angle for PJR was 60° external rotation, starting from 40°. TTDMD was tested from a position of 20° external rotation. Repeated measures ANOVAs were used to determine differences between PJR absolute and variable errors and TTDMD for the control and experimental conditions. Pain was elicited with a median 7 on the Numeric Pain Rating Scale. TTDMD was significantly decreased for the experimental pain condition compared to baseline and recovery conditions (≈30%, P = 0.003). No significant differences were found for absolute (P = 0.152) and variable (P = 0.514) error for PJR. Movement sense was enhanced for the experimental sub-acromial pain condition, which may reflect protective effects of the central nervous system in response to the pain. Where decreased passive proprioception is observed in shoulders with injuries, these may be due to a combination of peripheral tissue injury and neural adaptations that differ from those due to acute pain. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Effect of experimental chewing on masticatory muscle pain onset

    PubMed Central

    CONTI, Paulo César Rodrigues; SILVA, Rafael dos Santos; de ARAUJO, Carlos dos Reis Pereira; ROSSETI, Leylha Maria N.; YASSUDA, Shigueharu; da SILVA, Renato Oliveira Ferreira; PEGORARO, Luiz Fernando

    2011-01-01

    Objectives To evaluate the effect of a chewing exercise on pain intensity and pressurepain threshold in patients with myofascial pain. Methods Twenty-nine consecutive women diagnosed with myofascial pain (MFP) according to the Research Diagnostic Criteria comprised the experimental group and 15 healthy age-matched female were used as controls. Subjects were asked to chew a gum stick for 9 min and to stay at rest for another 9 min afterwards. Pain intensity was rated on a visual analog scale (VAS) every 3 min. At 0, 9 and 18 min, the pressure-pain threshold (PPT) was measured bilaterally on the masseter and the anterior, medium, and posterior temporalis muscles. Results Patients with myofascial pain reported increase (76%) and no change (24%) on the pain intensity measured with the VAS. A reduction of the PPT at all muscular sites after the exercise and a non-significant recovery after rest were also observed. Conclusion The following conclusions can be drawn: 1. there are at least two subtypes of patients with myofascial pain that respond differently to experimental chewing; 2. the chewing protocol had an adequate discriminative ability in distinguishing patients with myofascial pain from healthy controls. PMID:21437467

  19. Affect balance style, experimental pain sensitivity, and pain-related responses

    PubMed Central

    Sibille, Kimberly T.; Kindler, Lindsay L.; Glover, Toni L.; Staud, Roland; Riley, Joseph L.; Fillingim, Roger B.

    2011-01-01

    Objectives Affect is neurobiologically based, influences emotions, contributes to temperamental characteristics, and can be evaluated from both a state and trait perspective. Associations between state-related positive affect (PA), negative affect (NA), and chronic pain have been investigated. However, little is known about the relationship between trait affect patterns and pain-related experiences. Affect balance style (ABS) provides a framework to assess the combined contribution of trait PA and NA. Psychological factors and experimental pain sensitivity are indicated as predictors of chronic pain onset. The current study investigated the relationship between ABS, pain sensitivity, and pain-related measures in healthy adults. Methods Subjects (n=372) completed quantitative sensory testing, pain-related questionnaires, and the Positive and Negative Affect Scale (PANAS). ABS groups were categorized as Healthy (high PA, low NA), Low (low PA, low NA), Depressive (low PA, high NA), and Reactive (high PA, high NA). Z-scores were computed for three experimental pain measures: ischemic, pressure, and heat. Results ABS groups significantly differed on ischemic pain sensitivity and pain-related measures. Specifically, the Healthy group demonstrated lower ischemic pain sensitivity compared to the Reactive group (p=0.02); the Depressive and Reactive groups endorsed higher somatic symptoms compared to the Healthy group (p<0.02); the Low and Depressive groups reported more physical stimuli sensitivity than the Healthy group (p<0.02); and the Reactive group indicated more passive coping strategies then the Low and Healthy groups (p=0.001). Discussion Findings from the study suggest that among healthy adults, trait affect patterns are associated with ischemic experimental pain sensitivity and other pain-related measures. PMID:22367502

  20. Affect balance style, experimental pain sensitivity, and pain-related responses.

    PubMed

    Sibille, Kimberly T; Kindler, Lindsay L; Glover, Toni L; Staud, Roland; Riley, Joseph L; Fillingim, Roger B

    2012-06-01

    Affect is neurobiologically based, influences emotions, contributes to temperamental characteristics, and can be evaluated from both state and trait perspectives. Associations between state-related positive affect (PA), negative affect (NA), and chronic pain have been investigated. However, little is known about the relationship between trait affect patterns and pain-related experiences. Affect balance style (ABS) provides a framework to assess the combined contribution of trait PA and NA. Psychological factors and experimental pain sensitivity are indicated as predictors of chronic pain onset. The current study investigated the relationship between ABS, pain sensitivity, and pain-related measures in healthy adults. Participants (n=372) completed quantitative sensory testing, pain-related questionnaires, and the Positive and Negative Affect Scale. ABS groups were categorized as Healthy (high PA, low NA), Low (low PA, low NA), Depressive (low PA, high NA), and Reactive (high PA, high NA). Z-scores were computed for 3 experimental pain measures: ischemic, pressure, and heat. ABS groups significantly differed on ischemic pain sensitivity and pain-related measures. Specifically, the Healthy group demonstrated lower ischemic pain sensitivity compared with the Reactive group (P=0.02); the Depressive and Reactive groups endorsed higher somatic symptoms compared with the Healthy group (P<0.02); the Low and Depressive groups reported more physical stimuli sensitivity than the Healthy group (P<0.02); and the Reactive group indicated more passive coping strategies then the Low and Healthy groups (P=0.001). Findings from the study suggest that among healthy adults, trait affect patterns are associated with ischemic experimental pain sensitivity and other pain-related measures.

  1. Experimental verification of optical models of graphene with multimode slab waveguides.

    PubMed

    Chang, Zeshan; Chiang, Kin Seng

    2016-05-01

    We compare three optical models of graphene, namely, the interface model, the isotropic model, and the anisotropic model, and verify them experimentally with two multimode slab waveguide samples operating at the wavelengths of 632.8 and 1536 nm. By comparing the calculated graphene-induced losses and the measurement data, we confirm that the interface model and the anisotropic model give correct results for both the transverse electric (TE) and transverse magnetic modes, while the isotropic model gives correct results only for the TE modes. With the experimental data, we also quantitatively verify the widely used expression for the surface conductivity of graphene in the optical regime. Our findings clarify the issue of modeling graphene in the analysis of graphene-incorporated waveguides and offer deeper insight into the optical properties of graphene for waveguide applications.

  2. [Multimodal integrated assessment and treatment of patients with back pain. Pain related results and ability to work].

    PubMed

    Marnitz, U; Weh, L; Müller, G; Seidel, W; Bienek, K; Lindena, G; Gussek, A

    2008-08-01

    The results of conventional chronic back pain therapy are unsatisfactory. Deconditioning, psychosocial disorders and prolonged disability are common sequelae. The health insurance fund Deutsche Angestellten Krankenkasse (DAK) offers an interdisciplinary assessment by the Berlin-Brandenburg back pain network (BBR) to its members with ongoing work disability on account of back pain. After medical, physiotherapeutic and psychological exploration one of the following four options is suggested: further diagnostics, outpatient monomodal treatment, day-care pain management program of two intensities or inpatient pain treatment. The data of 394 patients with the leading diagnostic group of back pain (M54, ICD 10, 65.7%) and disability for 92.7 days (mean) are presented. The patients were severely impaired in physical and psychosocial aspects. The chronification was moderate (stage II-III of Mainz Staging System, MPSS). The success of treatment was evaluated 6 months after the initial assessment. All groups showed a significant reduction of pain, anxiety and depression whereas the wellbeing and daily activities improved, but best in the day-care pain management groups. Patient selection by a health fund, interdisciplinary assessment and severity adapted treatment resulted in significant reduction in pain and functional improvement in disabled back pain patients.

  3. Multimodal analgesia in moderate-to-severe pain: a role for a new fixed combination of dexketoprofen and tramadol.

    PubMed

    Varrassi, Giustino; Hanna, Magdi; Macheras, Giorgos; Montero, Antonio; Montes Perez, Antonio; Meissner, Winfried; Perrot, Serge; Scarpignato, Carmelo

    2017-06-01

    Untreated and under-treated pain represent one of the most pervasive health problems, which is worsening as the population ages and accrues risk for pain. Multiple treatment options are available, most of which have one mechanism of action, and cannot be prescribed at unlimited doses due to the ceiling of efficacy and/or safety concerns. Another limitation of single-agent analgesia is that, in general, pain is due to multiple causes. Combining drugs from different classes, with different and complementary mechanism(s) of action, provides a better opportunity for effective analgesia at reduced doses of individual agents. Therefore, there is a potential reduction of adverse events, often dose-related. Analgesic combinations are recommended by several organizations and are used in clinical practice. Provided the two agents are combined in a fixed-dose ratio, the resulting medication may offer advantages over extemporaneous combinations. Dexketoprofen/tramadol (25 mg/75 mg) is a new oral fixed-dose combination offering a comprehensive multimodal approach to moderate-to-severe acute pain that encompasses central analgesic action, peripheral analgesic effect and anti-inflammatory activity, together with a good tolerability profile. The analgesic efficacy of dexketoprofen/tramadol combination is complemented by a favorable pharmacokinetic and pharmacodynamic profile, characterized by rapid onset and long duration of action. This has been well documented in both somatic- and visceral-pain human models. This review discusses the available clinical evidence and the future possible applications of dexketoprofen/tramadol fixed-dose combination that may play an important role in the management of moderate-to-severe acute pain.

  4. A Magnetoencephalography study of multi-modal processing of pain anticipation in primary sensory cortices

    PubMed Central

    Gopalakrishnan, Raghavan; Burgess, Richard C.; Plow, Ela B.; Floden, Darlene; Machado, Andre G

    2015-01-01

    Pain anticipation plays a critical role in pain chronification and results in disability due to pain avoidance. It is important to understand how different sensory modalities (auditory, visual or tactile) may influence pain anticipation as different strategies could be applied to mitigate anticipatory phenomena and chronification. In this study, using a countdown paradigm, we evaluated with magnetoencephalography the neural networks associated with pain anticipation elicited by different sensory modalities in normal volunteers. When encountered with well-established cues that signaled pain, visual and somatosensory cortices engaged the pain neuromatrix areas early during the countdown process, whereas auditory cortex displayed delayed processing. In addition, during pain anticipation, visual cortex displayed independent processing capabilities after learning the contextual meaning of cues from associative and limbic areas. . Interestingly, cross-modal activation was also evident and strong when visual and tactile cues signaled upcoming pain. Dorsolateral prefrontal cortex and mid-cingulate cortex showed significant activity during pain anticipation regardless of modality. Our results show pain anticipation is processed with great time efficiency by a highly specialized and hierarchical network. The highest degree of higher-order processing is modulated by context (pain) rather than content (modality) and rests within the associative limbic regions, corroborating their intrinsic role in chronification. PMID:26210576

  5. Pain by Association? Experimental Modulation of Human Pain Thresholds Using Classical Conditioning.

    PubMed

    Madden, Victoria J; Bellan, Valeria; Russek, Leslie N; Camfferman, Danny; Vlaeyen, Johan W S; Moseley, G Lorimer

    2016-10-01

    A classical conditioning framework is often used for clinical reasoning about pain that persists after tissue healing. However, experimental studies demonstrating classically conditioned pain in humans are lacking. The current study tested whether non-nociceptive somatosensory stimuli can come to modulate pain thresholds after being paired with painful nociceptive stimuli in healthy humans. We used a differential simultaneous conditioning paradigm in which one nonpainful vibrotactile conditioned stimulus (CS(+)) was simultaneously paired with an unconditioned painful laser stimulus, and another vibrotactile stimulus (CS(-)) was paired with a nonpainful laser stimulus. After acquisition, at-pain-threshold laser stimuli were delivered simultaneously with a CS(+) or CS(-) vibrotactile stimulus. The primary outcome was the percentage of at-threshold laser stimuli that were reported as painful. The results were as expected: after conditioning, at-threshold laser trials paired with the CS(+) were reported as painful more often, as more intense, and as more unpleasant than those paired with the CS(-). This study provides new evidence that pain thresholds can be modulated via classical conditioning, even when the stimulus used to test the threshold cannot be anticipated. As such, it lays a critical foundation for further investigations of classical conditioning as a possible driver of persistent pain. This study provides new evidence that human pain thresholds can be influenced by non-nociceptive somatosensory stimuli, via a classical conditioning effect. As such, it lays a critical foundation for further investigations of classical conditioning as a possible driver of persistent pain. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

  6. Does an online psychological intervention improve self-efficacy and disability in people also receiving Multimodal Manual Therapy for chronic low back pain compared to Multimodal Manual Therapy alone? Design of a randomized controlled trial.

    PubMed

    Petrozzi, M John; Leaver, Andrew; Jones, Mairwen K; Ferreira, Paulo H; Rubinstein, Sidney M; Mackey, Martin G

    2015-01-01

    Various interventions are available for the treatment of chronic low back pain (LBP), including Manual Therapy and Cognitive Behavioural Therapy (CBT). The purpose of this study is to evaluate whether the addition of an internet-based CBT program leads to better outcomes in patients who are treated with multimodal manual therapy for chronic LBP. A randomized controlled trial comparing a combined intervention, consisting of internet-based CBT utilising MoodGYM plus multimodal manual therapy, to multimodal manual therapy alone for patients with chronic LBP. Multimodal manual therapy will be delivered by experienced chiropractors and physiotherapists. Treatment sessions will consist of a combination of joint and soft tissue mobilisation; spinal manipulation as well as muscle and fascia massage; education and reassurance; and rehabilitative exercise prescription. In total, 108 adult participants will be recruited from multiple chiropractic and physiotherapy private practices in Australia. Participants older than 18 years of age and diagnosed with chronic non-specific LBP will be included in the trial, where chronic LBP is defined as continuous or fluctuating pain for a minimum of three months. The Keele STarT Back screening tool will be used to screen for potential participants who are in the medium risk category. The primary outcomes are self efficacy and disability measured by the Patient Self-Efficacy Questionnaire (PSEQ) and Roland Morris Disability Questionnaire (RMDQ) respectively. Secondary outcome measures will assess pain, catastrophising, depression, anxiety, stress and work ability. Participants will be randomly allocated into one of two groups. Both groups will receive an upper limit of 12 multimodal manual therapy sessions over a period of 8 weeks. The intervention group will also receive five weeks of MoodGYM covering five modules in total. Assessment will be conducted at pre-treatment, post-treatment 8- and follow-up at 26- and 52 weeks. In addition

  7. SPONTANEOUS CHRONIC PAIN AFTER EXPERIMENTAL THORACTOMY REVEALED BY CONDITIONED PLACE PREFERENCE: morphine differentiates tactile evoked pain from spontaneous pain

    PubMed Central

    Hung, Ching-Hsia; Wang, Jeffrey Chi-Fei; Strichartz, Gary

    2015-01-01

    Chronic pain following surgery limits social activity, interferes with work and causes emotional suffering. A major component of such pain is is reported as “resting” or spontaneous pain with no apparent external stimulus. Although experimental animal models can simulate the stimulus-evoked chronic pain that occurs after surgery, there have been no studies of spontaneous chronic pain in such models. Here the Conditioned Place Preference (CPP) paradigm was used to reveal resting pain after experimental thoracotomy. Male Sprague-Dawley rats received a thoracotomy with 1 hour rib retraction, resulting in evoked tactile hypersensitivity, previously shown to last for at least 9 weeks. Intraperitoneal injections of morphine (2.5 mg/kg) or gabapentin (40mg/kg) gave equivalent 2-3h long relief of tactile hypersensitivity, when tested 12-14 days post-operative. In separate experiments, single trial CPP was conducted 1 week before thoracotomy and then 12 days (gabapentin) or 14 days (morphine) after surgery, followed the next day by one conditioning sesssion with morphine or gabapentin, both vs saline. The gabapentin-conditioned, but not the morphine-conditioned rats showed a significant preference for the analgesia-paired chamber, despite the two agents’ equivalent effect in relieving tactile allodynia. These results show that experimental thoracotomy in rats causes spontaneous pain, and that some analgesics, such as morphine, that reduce evoked pain do not also relieve resting pain, suggesting that pathophysiological mechanisms differ between these two aspects of long-term post-operative pain. PMID:26116369

  8. Interaction between histamine-induced itch and experimental muscle pain.

    PubMed

    Wasner, G; Schwarz, K; Schattschneider, J; Binder, A; Jensen, T S; Baron, R

    2004-06-01

    Itch sensation can be inhibited by simultaneously applied cutaneous pain at the same skin site via a central mechanism. Deep muscle pain is often associated with sensory changes in the corresponding dermatome. We investigated whether experimentally induced muscle pain has any influence on histamine-induced itch and vice versa in a double blind placebo-controlled study. Experiments were performed in 18 healthy subjects. In nine individuals control iontophoresis of histamine into the forearm produced a distinct itch sensation. Another nine individuals participated in an additional experiment in which histamine and saline were iontophoresed on the forearm in a randomized double-blinded two-way crossover design after intramuscular injection of capsaicin into the ipsilateral brachioradial muscle. Capsaicin-induced muscle pain reduced itch sensation significantly. In contrast, capsaicin-induced muscle pain increased significantly after cutaneous histamine application compared to muscle pain after iontophoresis of saline (placebo). These novel data indicate that muscle pain inhibits itch and histamine increases muscle pain. A bi-directional interaction between cutaneous histamine-sensitive afferents and nociceptive muscle afferents via central mechanisms is suggested.

  9. Multimodal approaches to the management of neuropathic pain: the role of topical analgesia.

    PubMed

    de Leon-Casasola, Oscar A

    2007-03-01

    Because of their localized activity and low systemic absorption, topical analgesics have a favorable safety profile and a low risk for drug-drug interactions. There is a growing body of evidence on the efficacy and safety of these agents in a variety of pain disorders, including the most prevalent neuropathic pain conditions. The molecular basis for the usage of peripheral analgesics in neuropathic pain and the available clinical trial evidence for a wide variety of topical agents are reviewed.

  10. Decreased pain sensitivity among people with schizophrenia: a meta-analysis of experimental pain induction studies.

    PubMed

    Stubbs, Brendon; Thompson, Trevor; Acaster, Sarah; Vancampfort, Davy; Gaughran, Fiona; Correll, Christoph U

    2015-11-01

    Patients with schizophrenia report reduced pain sensitivity in clinical studies, but experimental studies are required to establish pain sensitivity as a potential endophenotype. We conducted a systematic review of electronic databases from database inception until April 15, 2015, including experimental studies investigating pain among patients with schizophrenia spectrum disorder vs healthy controls. A random-effect meta-analysis yielding Hedges' g ±95% confidence intervals (CIs) as the effect size (ES) measure was conducted. Primary outcome was a pooled composite of pain threshold and pain tolerance; secondary outcomes included these parameters individually, plus sensory threshold, physiological pain response, and pain intensity or unpleasantness. Across 17 studies, patients with schizophrenia spectrum disorder (n = 387; age, 30.7 ± 6.9 years; females, 31.9%; illness duration, 7.0 ± 5.7 years) were compared with controls (n = 483; age, 29.5 ± 7.4 years; females, 31.0%). Patients had elevated pain threshold/pain tolerance vs controls (ES = 0.583; 95% CI, 0.212-0.954; P = 0.002; studies = 15). Results were similar in antipsychotic-free individuals (ES = 0.599; 95% CI, 0.291-0.907; P < 0.0001; studies = 8), with trend-level significance in antipsychotic-treated individuals (ES = 0.566; 95% CI, -0.007 to 1.125; P = 0.047; studies = 9). Likewise, patients with schizophrenia had increased pain tolerance (ES = 0.566; 95% CI, 0.235-0.897; P = 0.0001; studies = 6), sensory threshold (ES = 1.16; 95% CI, 0.505-1.727; P < 0.0001; studies = 5), and pain threshold (ES = 0.696; 95% CI, 0.407-0.986; P < 0.001; studies = 9), as well as reduced physiological response to noxious stimuli (ES = 0.456; 95% CI, 0.131-0.783; P = 0.006) and pain intensity/unpleasantness ratings (ES = 0.547; 95% CI, 0.146-0.949; P = 0.008). Findings were similarly significant in antipsychotic-free patients with schizophrenia (analysable parameters = 4) and antipsychotic-treated individuals (analysable

  11. Multi-Mode transport modeling of the International Thermonuclear Experimental Reactor (ITER)

    SciTech Connect

    Bateman, G.; Kritz, A.H.; Kinsey, J.E.; Redd, A.J.

    1998-06-01

    Predictions are made for the performance of the International Thermonuclear Experimental Reactor (ITER) [R. Aymar, V. Chuyanov, M. Huguet, R. Parker, and Y. Shimomura, in {ital Proceedings of the Sixteenth International Atomic Energy Agency Fusion Energy Conference, Montr{acute e}al, Canada 1996} (International Atomic Energy Agency, Vienna, 1997), Paper IAEA-CN-64/01-1] design using the Multi-Mode model in the time-dependent one- and one-half-dimensional (1-1/2-D) BALDUR [C. E. Singer {ital et al.}, Comput. Phys. Commun. {bold 49}, 275 (1988)] transport code. This model predicts the temperature and density profiles observed in present-day tokamak experiments more closely on the average than other models currently available. Simulations using the Multi-Mode transport model, with its inherent gyro-Bohm scaling, indicate that ITER will ignite, even with edge temperatures as low as 0.25 keV (L-mode, or low-confinement mode, boundary conditions) or with volume averaged density as low as 0.775{times}10{sup 20}m{sup {minus}3} (just below the Greenwald density limit, when T{sub edge}=0.75keV). The ignition is found to be thermally stable, and the fusion power production is easily controlled by varying plasma density, impurity content, or edge temperatures. The nonequilibrium impurity radiation model used in these simulations predicts that a significant fraction of the fusion power is radiated when conditions are close to marginal ignition. {copyright} {ital 1998 American Institute of Physics.}

  12. Effects of hypnotic analgesia and hypnotizability on experimental ischemic pain.

    PubMed

    DeBenedittis, G; Panerai, A A; Villamira, M A

    1989-01-01

    Mechanisms of hypnotic analgesia are still poorly understood and conflicting data are reported regarding the underlying neurochemical correlates. The present study was designed to investigate the effects of hypnotically induced analgesia and hypnotizability on experimental ischemic pain, taking into account pain and distress tolerance as well as the neurochemical correlates. 11 high hypnotizable Ss and 10 low hypnotizable Ss, as determined by scores on the Stanford Hypnotic Susceptibility Scale, Form C (Weitzenhoffer & E. R. Hilgard, 1962), were administered an ischemic pain test in both waking and hypnotic conditions. The following variables were measured: (a) pain and distress tolerance, (b) anxiety levels, and (c) plasma concentrations of beta-endorphin and adrenocorticotropic hormone (ACTH). Results confirmed significant increases of pain and distress tolerance during hypnosis as compared to the waking state, with positive correlations between pain and distress relief and hypnotizability. Moreover, a hypnotically induced dissociation between the sensory-discriminative and the affective-motivational dimensions of pain experience was found, but only in high hypnotizable Ss. Hypnotic analgesia was unrelated to anxiety reduction and was not mediated either by endorphins or by ACTH.

  13. Effectiveness of Inclusion of Dry Needling in a Multimodal Therapy Program for Patellofemoral Pain: A Randomized Parallel-Group Trial.

    PubMed

    Espí-López, Gemma V; Serra-Añó, Pilar; Vicent-Ferrando, Juan; Sánchez-Moreno-Giner, Miguel; Arias-Buría, Jose L; Cleland, Joshua; Fernández-de-Las-Peñas, César

    2017-06-01

    Study Design Randomized controlled trial. Background Evidence suggests that multimodal interventions that include exercise therapy may be effective for patellofemoral pain (PFP); however, no study has investigated the effects of trigger point (TrP) dry needling (DN) in people with PFP. Objectives To compare the effects of adding TrP DN to a manual therapy and exercise program on pain, function, and disability in individuals with PFP. Methods Individuals with PFP (n = 60) recruited from a public hospital in Valencia, Spain were randomly allocated to manual therapy and exercises (n = 30) or manual therapy and exercise plus TrP DN (n = 30). Both groups received the same manual therapy and strengthening exercise program for 3 sessions (once a week for 3 weeks), and 1 group also received TrP DN to active TrPs within the vastus medialis and vastus lateralis muscles. The pain subscale of the Knee injury and Osteoarthritis Outcome Score (KOOS; 0-100 scale) was used as the primary outcome. Secondary outcomes included other subscales of the KOOS, the Knee Society Score, the International Knee Documentation Committee Subjective Knee Evaluation Form (IKDC), and the numeric pain-rating scale. Patients were assessed at baseline and at 15-day (posttreatment) and 3-month follow-ups. Analysis was conducted with mixed analyses of covariance, adjusted for baseline scores. Results At 3 months, 58 subjects (97%) completed the follow-up. No significant between-group differences (all, P>.391) were observed for any outcome: KOOS pain subscale mean difference, -2.1 (95% confidence interval [CI]: -4.6, 0.4); IKDC mean difference, 2.3 (95% CI: -0.1, 4.7); knee pain intensity mean difference, 0.3 (95% CI: -0.2, 0.8). Both groups experienced similar moderate-to-large within-group improvements in all outcomes (standardized mean differences of 0.6 to 1.1); however, only the KOOS function in sport and recreation subscale surpassed the prespecified minimum important change. Conclusion The current

  14. Nonpainful wide-area compression inhibits experimental pain

    PubMed Central

    Honigman, Liat; Bar-Bachar, Ofrit; Yarnitsky, David; Sprecher, Elliot; Granovsky, Yelena

    2016-01-01

    Abstract Compression therapy, a well-recognized treatment for lymphoedema and venous disorders, pressurizes limbs and generates massive non-noxious afferent sensory barrages. The aim of this study was to study whether such afferent activity has an analgesic effect when applied on the lower limbs, hypothesizing that larger compression areas will induce stronger analgesic effects, and whether this effect correlates with conditioned pain modulation (CPM). Thirty young healthy subjects received painful heat and pressure stimuli (47°C for 30 seconds, forearm; 300 kPa for 15 seconds, wrist) before and during 3 compression protocols of either SMALL (up to ankles), MEDIUM (up to knees), or LARGE (up to hips) compression areas. Conditioned pain modulation (heat pain conditioned by noxious cold water) was tested before and after each compression protocol. The LARGE protocol induced more analgesia for heat than the SMALL protocol (P < 0.001). The analgesic effect interacted with gender (P = 0.015). The LARGE protocol was more efficient for females, whereas the MEDIUM protocol was more efficient for males. Pressure pain was reduced by all protocols (P < 0.001) with no differences between protocols and no gender effect. Conditioned pain modulation was more efficient than the compression-induced analgesia. For the LARGE protocol, precompression CPM efficiency positively correlated with compression-induced analgesia. Large body area compression exerts an area-dependent analgesic effect on experimental pain stimuli. The observed correlation with pain inhibition in response to robust non-noxious sensory stimulation may suggest that compression therapy shares similar mechanisms with inhibitory pain modulation assessed through CPM. PMID:27152691

  15. Nonpainful wide-area compression inhibits experimental pain.

    PubMed

    Honigman, Liat; Bar-Bachar, Ofrit; Yarnitsky, David; Sprecher, Elliot; Granovsky, Yelena

    2016-09-01

    Compression therapy, a well-recognized treatment for lymphoedema and venous disorders, pressurizes limbs and generates massive non-noxious afferent sensory barrages. The aim of this study was to study whether such afferent activity has an analgesic effect when applied on the lower limbs, hypothesizing that larger compression areas will induce stronger analgesic effects, and whether this effect correlates with conditioned pain modulation (CPM). Thirty young healthy subjects received painful heat and pressure stimuli (47°C for 30 seconds, forearm; 300 kPa for 15 seconds, wrist) before and during 3 compression protocols of either SMALL (up to ankles), MEDIUM (up to knees), or LARGE (up to hips) compression areas. Conditioned pain modulation (heat pain conditioned by noxious cold water) was tested before and after each compression protocol. The LARGE protocol induced more analgesia for heat than the SMALL protocol (P < 0.001). The analgesic effect interacted with gender (P = 0.015). The LARGE protocol was more efficient for females, whereas the MEDIUM protocol was more efficient for males. Pressure pain was reduced by all protocols (P < 0.001) with no differences between protocols and no gender effect. Conditioned pain modulation was more efficient than the compression-induced analgesia. For the LARGE protocol, precompression CPM efficiency positively correlated with compression-induced analgesia. Large body area compression exerts an area-dependent analgesic effect on experimental pain stimuli. The observed correlation with pain inhibition in response to robust non-noxious sensory stimulation may suggest that compression therapy shares similar mechanisms with inhibitory pain modulation assessed through CPM.

  16. IL17 Mediates Pelvic Pain in Experimental Autoimmune Prostatitis (EAP)

    PubMed Central

    Murphy, Stephen F.; Schaeffer, Anthony J.; Done, Joseph; Wong, Larry; Bell-Cohn, Ashlee; Roman, Kenny; Cashy, John; Ohlhausen, Michelle; Thumbikat, Praveen

    2015-01-01

    Chronic pelvic pain syndrome (CPPS) is the most common form of prostatitis, accounting for 90–95% of all diagnoses. It is a complex multi-symptom syndrome with unknown etiology and limited effective treatments. Previous investigations highlight roles for inflammatory mediators in disease progression by correlating levels of cytokines and chemokines with patient reported symptom scores. It is hypothesized that alteration of adaptive immune mechanisms results in autoimmunity and subsequent development of pain. Mouse models of CPPS have been developed to delineate these immune mechanisms driving pain in humans. Using the experimental autoimmune prostatitis (EAP) in C57BL/6 mice model of CPPS we examined the role of CD4+T-cell subsets in the development and maintenance of prostate pain, by tactile allodynia behavioral testing and flow cytometry. In tandem with increased CD4+IL17A+ T-cells upon EAP induction, prophylactic treatment with an anti-IL17 antibody one-day prior to EAP induction prevented the onset of pelvic pain. Therapeutic blockade of IL17 did not reverse pain symptoms indicating that IL17 is essential for development but not maintenance of chronic pain in EAP. Furthermore we identified a cytokine, IL7, to be associated with increased symptom severity in CPPS patients and is increased in patient prostatic secretions and the prostates of EAP mice. IL7 is fundamental to development of IL17 producing cells and plays a role in maturation of auto-reactive T-cells, it is also associated with autoimmune disorders including multiple sclerosis and type-1 diabetes. More recently a growing body of research has pointed to IL17’s role in development of neuropathic and chronic pain. This report presents novel data on the role of CD4+IL17+ T-cells in development and maintenance of pain in EAP and CPPS. PMID:25933188

  17. Postoperative Multimodal Analgesia Pain Management With Nonopioid Analgesics and Techniques: A Review.

    PubMed

    Wick, Elizabeth C; Grant, Michael C; Wu, Christopher L

    2017-07-01

    Amid the current opioid epidemic in the United States, the enhanced recovery after surgery pathway (ERAS) has emerged as one of the best strategies to improve the value and quality of surgical care and has been increasingly adopted for a broad range of complex surgical procedures. The goal of this article was to outline important components of opioid-sparing analgesic regimens. Regional analgesia, acetaminophen, nonsteroidal anti-inflammatory agents, gabapentinoids, tramadol, lidocaine, and/or the N-methyl-d-aspartate class of glutamate receptor antagonists have been shown to be effective adjuncts to narcotic analgesia. Nonsteroidal anti-inflammatory agents are not associated with an increase in postoperative bleeding. A meta-analysis of 27 randomized clinical trials found no difference in postoperative bleeding between the groups taking ketorolac tromethamine (33 of 1304 patients [2.5%]) and the control groups (21 of 1010 [2.1%]) (odds ratio [OR], 1.1; 95% CI, 0.61-2.06; P = .72). After adoption of the multimodal analgesia approach for a colorectal ERAS pathway, most patients used less opioids while in the hospital and many did not need opioids after hospital discharge, although approximately 50% of patients received some opioid during their stay. Multimodal analgesia is readily available and the evidence is strong to support its efficacy. Surgeons should use this effective approach for patients both using and not using the ERAS pathway to reduce opioid consumption.

  18. Multimodal stepped care approach with acupuncture and PPAR-α agonist palmitoylethanolamide in the treatment of a patient with multiple sclerosis and central neuropathic pain.

    PubMed

    Kopsky, David J; Hesselink, Jan M Keppel

    2012-03-01

    Central neuropathic pain is a common debilitating symptom in patients with multiple sclerosis. Side effects of analgesics often limit reaching therapeutic dosages. In this case report, a 61-year-old woman with chronic central neuropathic pain due to multiple sclerosis is described. Acupuncture could only partly and temporarily reduce the pain. However, after adding the natural compound palmitoylethanolamide, a glial modulator and peroxisome proliferator-activated receptor-α agonist, pain reduction was more pronounced and the interval between acupuncture sessions could be increased. A multimodal stepped care approach is demonstrated, with acupuncture and palmitoylethanolamide both influencing non-neuronal cells, such as activated glial cells, which are key factors in the development and maintenance of neuropathic pain.

  19. Hypoalgesic effect of caffeine in experimental ischemic muscle contraction pain.

    PubMed

    Myers, D E; Shaikh, Z; Zullo, T G

    1997-01-01

    It has been theorized that adenosine is a leading candidate for the metabolite responsible for ischemic muscle pain. The purpose of this study was to determine the effect of the non-selective adenosine receptor antagonist, caffeine, on ischemic skeletal muscle contraction pain. Seven healthy adult volunteers with no history of pain disorders, systemic disease, or habitual caffeine use, were chosen for the two-session, cross-over, double-blind study. Every subject received either 200 mg of caffeine (NoDoz, Bristol-Myers) or identical placebo 1 hour before each of the two trials. Ischemia of the forearm was achieved by inflation of a blood pressure cuff to 250 mm Hg. Forearm muscle activity was generated by performance of wrist curis using a 5-gram bar at a rate of 40 cycles per minute. Pain was rated at 15-second intervals for 1 minute using a visual analog scale (0 to 10) with verbal descriptors. Significance was determined by univariate and multivariate analyses of variance and covariance including repeated measures. Pain ratings at 15 seconds in the caffeine trial were significantly lower (P < 0.02) than those in the placebo trial. This effect continued at 30 seconds (P < 0.05). However, by 45 seconds, pain in the caffeine trial was not significantly lower (P = 0.4) than that in the placebo trial. These results show that high-dose caffeine exhibits considerable analgesic efficacy in experimental muscle pain, adding support for a role of adenosine in producing ischemic muscle contraction pain.

  20. Pregabalin as adjunct in a multimodal pain therapy after traumatic foot amputation - A case report of a 4-year-old girl.

    PubMed

    Wössner, Stephanie; Weber, Kirsten; Steinbeck, Anna C; Oberhauser, Markus; Feuerecker, Matthias

    2017-09-22

    The purpose of this case report is to describe a multimodal pain therapeutic concept including the adjunct use of pregabalin in a 4.5 year-old child after forefoot amputation. Phantom limb pain and sensation is a complex pain syndrome that is difficult to treat and prevent. 70-75% of all children develop such a pain syndrome after amputation. We describe here a paediatric patient who underwent forefoot amputation following traumatic foot injury and received multimodal pain therapy including pregabalin. A 4.5 year-old otherwise healthy girl suffered severe injuries of the right foot and lower leg during a motor vehicle accident. Due to development of severe necrosis, forefoot amputation had to be performed during the hospital stay. Initial pain therapy included paracetamol, ibuprofen, metamizol, morphine and fentanyl. With mounting pain and anxiety, regional anaesthesia of the distal sciatic nerve was administered in combination with a ketamine and morphine patient controlled analgesia pump (PCA). The peripheral blockade of the distal sciatic nerve was placed with the guidance of ultrasound and nerve stimulator. The PCA concept included a continuous basal rate combined with a bolus function. Although the regional anaesthesia was well positioned and functioning, there was inadequate pain control. The pain was described by the patient as short, highly intense and sharp sensations with intensity on the visual analogue scale (VAS) of 10 (out of 10). Furthermore, she suffered from anxiety episodes and sleep disturbance. The medical team decided to treat with pregabalin to resolve these issues while awaiting amputation (Lisfranc line). She received psychological counselling as adjunct treatment. This multimodal concept enabled an early and efficient pain reduction pre- and post-amputation and allowed for the possibility of a hospital discharge without any opioid pain medication. The multimodal pain therapy including pregabalin was well tolerated, safe and highly effective

  1. Effects of intrathecal ketorolac on human experimental pain

    PubMed Central

    Eisenach, James C.; Curry, Regina; Tong, Chuanyao; Houle, Timothy T.; Yaksh, Tony L.

    2010-01-01

    Background Nonsteroidal antiinflammatory drugs, the most commonly used analgesics, reduce pain by inhibiting cyclooxygenase at peripheral sites of inflammation, but potentially also by inhibiting cyclooxygenase in the central nervous system, especially the spinal cord. Animal studies suggest that products of cyclooxygenase in the spinal cord do not alter pain responses to acute noxious stimuli, but reduce pain and sensitization following peripheral inflammation. We used spinal injection of small doses of the cyclooxygenase inhibitor, ketorolac, to survey the role of spinal cyclooxygenase in human experimental pain and hypersensitivity states. Methods Following regulatory agency approval and informed consent, we examined the effect of 2.0 mg intrathecal ketorolac in 41 healthy volunteers to acute noxious thermal stimuli in normal skin and to mechanical stimuli in skin sensitized by topical capsaicin or ultraviolet burn. We also examined the effect of intravenous ketorolac, Results Intrathecal ketorolac reduced hypersensitivity when it was induced by a combination of ultraviolet burn plus intermittent heat and, according to one of two analytical strategies, when it was induced by ultraviolet burn alone. Conclusions These data suggest a more limited role for spinal cord cyclooxygenase in human pain states than predicted by studies in animals. PMID:20395821

  2. Experimentally induced pain perception is acutely reduced by aerobic exercise in people with chronic low back pain.

    PubMed

    Hoffman, Martin D; Shepanski, Melissa A; Mackenzie, Sean P; Clifford, Philip S

    2005-01-01

    This study examined whether subjects with chronic low back pain demonstrate exercise-induced analgesia to experimentally induced pressure pain. We employed a repeated measures design to study eight subjects with chronic low back pain (mean +/- standard deviation age = 40 +/- 10, duration of pain = 7 +/- 4 years). Pain ratings were measured immediately before and 2 minutes and 32 minutes after 25 minutes of cycle ergometry (5 minutes at 50% peak oxygen uptake, then 20 minutes at 70% peak oxygen uptake). We based the pain ratings on subject input on a visual analog scale at 10-second intervals during the 2-minute pressure pain stimulus to the nondominant index finger. Compared with preexercise values, pain ratings were significantly (p < 0.05) decreased after exercise at both 2 and 32 minutes postexercise. We conclude that pressure pain perception can be reduced for more than 30 minutes following aerobic exercise from leg cycling among people with chronic low back pain.

  3. Multimodal Chiropractic Care for Pain and Disability in a Patient Diagnosed With Ehlers-Danlos Syndrome-Hypermobility Type: A Case Report.

    PubMed

    Strunk, Richard G

    2017-06-01

    The purpose of this article is to describe the clinical response to multimodal chiropractic treatment of a patient diagnosed with Ehlers-Danlos syndrome, hypermobility type (EDS-HT), and chronic pain. A 22-year-old woman presented with severe chronic neck and low back pain, headaches, and bilateral hand pain and stiffness. In addition to these pain complaints, the patient had a family history of EDS, weekly or daily recurring joint dislocations, and upper and lower extremity joint hypermobility. As a result of her significant history and examination findings, which met the Brighton and Villefranche criteria, she was diagnosed with EDS-HT. Treatment primarily consisted of low force joint manipulative therapy and soft tissue therapy intermittently over 21 months concurrently with conventional and complementary medical care. Multiple outcome questionnaires were administered pragmatically at follow-up intervals of 3, 5½, 8½, 19, and 21 months, including but not limited to the Headache and Neck Disability Indices and the Oswestry Low Back Questionnaire. The patient had clinically meaningful improvements on the Neck Disability Index, the Headache Disability Index, and the Revised Oswestry after 3, 5½, 8½, and 21 months from baseline. This patient with EDS-HT had clinically meaningful decreases in disability, headache, and spine pain after a course of multimodal chiropractic care combined with conventional and complementary medical care.

  4. Pain management in total knee arthroplasty: efficacy of a multimodal opiate-free protocol

    PubMed Central

    CANATA, GIAN LUIGI; CASALE, VALENTINA; CHIEY, ALFREDO

    2016-01-01

    Purpose this study was conducted to identify the most effective method of postoperative pain management, comparing the intravenous opiate infusion protocol with the use of a single periarticular local anesthetic infiltration (LAI) in patients undergoing total knee arthroplasty (TKA) surgery. Methods 50 patients submitted to TKA surgery between 2013 and 2015 were divided into two groups. Buprenorphine was administered intravenously to the patients in Group A, while the Group B patients received a single periarticular LAI (ropivacaine and ketorolac) during surgery. Pain was assessed using a visual analog scale (VAS) and the knee injury and osteoarthritis outcome score. Hemoglobin and hematocrit were measured in the early postoperative period and at 40 days post-surgery. Range of motion and inflammatory markers were also assessed. Statistical analysis was performed using Student’s t-test. Results student’s t-test showed no significant difference between the groups in functional outcomes or blood values, but a difference in VAS score on the day of surgery was found (p < 0.0001), in favor of Group B. Conclusions LAI considerably reduces postoperative pain, allowing rapid mobilization and accelerating functional recovery. Level of evidence Level I, prospective single-blind randomized trial. PMID:28217658

  5. Searching for success: Development of a combined patient-reported-outcome ("PRO") criterion for operationalizing success in multi-modal pain therapy.

    PubMed

    Donath, Carolin; Dorscht, Lisa; Graessel, Elmar; Sittl, Reinhard; Schoen, Christoph

    2015-07-17

    There is a need for a way to measure success in multi-modal pain therapy that researchers and clinicians can agree upon. According to developments in health services research, operationalizing success should take patient-reported outcomes into account. We will present a success criterion for pain therapy that combines different patient-reported variables and includes validity measures. The usable criterion should be part of a statistically significant and satisfactory model identifying predictors of successful pain therapy. Routine data from 375 patients treated with multi-modal pain therapy from 2008 to 2013 were used. The change scores of five constructs were used for the combined success criterion: pain severity, disability due to pain, depressiveness, and physical- and mental-health-related quality of life. According to the literature, an improvement of at least ½ standard deviation was required on at least four of the five constructs to count as successful. A three-step analytical approach including multiple binary logistic regression analysis was chosen to identify the predictors of therapy success with the success criterion as the dependent variable. A total of 58.1% of the patients were classified as successful. Convergent and predictive validity data show significant correlations between the criterion and established instruments, while discriminative validity could also be shown. A multiple binary logistic regression analysis confirmed the feasibility; a significant model (Chi(2) (8) = 52.585; p < .001) that explained 17.6% of the variance identified the following predictors of therapy success: highest pain severity in the last 4 weeks, disability due to pain, and number of physician visits in the last 6 months. It is possible to develop a feasible success criterion that combines several variables and includes patient-reported outcomes ("PROs") with routine data that can be used in a predictor analysis in multi-modal pain therapy. The criterion

  6. Returning to work - a long-term process reaching beyond the time frames of multimodal non-specific back pain rehabilitation.

    PubMed

    Hellman, Therese; Jensen, Irene; Bergström, Gunnar; Busch, Hillevi

    2015-01-01

    To explore and describe health professionals' experience of working with return to work (RTW) in multimodal rehabilitation for people with non-specific back pain. An interview study using qualitative content analysis. Fifteen participants were interviewed, all were working with multimodal rehabilitation for people with non-specific back pain in eight different rehabilitation units. The participants experienced RTW as a long-term process reaching beyond the time frames of the multimodal rehabilitation (MMR). Their attitudes and, their patients' condition, impacted on their work which focused on psychological and physical well-being as well as participation in everyday life. They often created an action plan for the RTW process, however the responsibility for its realisation was transferred to other actors. The participants described limited interventions in connection with patients' workplaces. Recommended support in the RTW process in MMR comprises the provision of continuous supervision of vocational issues for the health care professionals, the development of guidelines and a checklist for how to work in close collaboration with patients' workplaces and employers, the provision of long-term follow-up in relation to the patients' work, and the development of proper interventions in order to promote transitions between all the different actors involved. Rehabilitation programs targeting return to work (RTW) for people with non-specific back pain needs to include features concretely focusing on vocational issues. Health and RTW is often seen as a linear process in which health comes before RTW. Rehabilitation programs could be tailored to better address the reciprocal relationship between health and work, in which they are interconnected and affect each other. The RTW process is reaching beyond the time frames of the multimodal rehabilitation but further support from the patients are asked for. The rehabilitation programs needs to be designed to provide long

  7. Pain patients' experiences of validation and invalidation from physicians before and after multimodal pain rehabilitation: Associations with pain, negative affectivity, and treatment outcome.

    PubMed

    Edlund, Sara M; Wurm, Matilda; Holländare, Fredrik; Linton, Steven J; Fruzzetti, Alan E; Tillfors, Maria

    2017-08-04

    Validating and invalidating responses play an important role in communication with pain patients, for example regarding emotion regulation and adherence to treatment. However, it is unclear how patients' perceptions of validation and invalidation relate to patient characteristics and treatment outcome. The aim of this study was to investigate the occurrence of subgroups based on pain patients' perceptions of validation and invalidation from their physicians. The stability of these perceptions and differences between subgroups regarding pain, pain interference, negative affectivity and treatment outcome were also explored. A total of 108 pain patients answered questionnaires regarding perceived validation and invalidation, pain severity, pain interference, and negative affectivity before and after pain rehabilitation treatment. Two cluster analyses using perceived validation and invalidation were performed, one on pre-scores and one on post-scores. The stability of patient perceptions from pre- to post-treatment was investigated, and clusters were compared on pain severity, pain interference, and negative affectivity. Finally, the connection between perceived validation and invalidation and treatment outcome was explored. Three clusters emerged both before and after treatment: (1) low validation and heightened invalidation, (2) moderate validation and invalidation, and (3) high validation and low invalidation. Perceptions of validation and invalidation were generally stable over time, although there were individuals whose perceptions changed. When compared to the other two clusters, the low validation/heightened invalidation cluster displayed significantly higher levels of pain interference and negative affectivity post-treatment but not pre-treatment. The whole sample significantly improved on pain interference and depression, but treatment outcome was independent of cluster. Unexpectedly, differences between clusters on pain interference and negative affectivity

  8. The comparative effectiveness of a multimodal program versus exercise alone for the secondary prevention of chronic low back pain and disability.

    PubMed

    Ewert, Thomas; Limm, Heribert; Wessels, Tina; Rackwitz, Berid; von Garnier, Katharina; Freumuth, Robert; Stucki, Gerold

    2009-09-01

    The objective of this study was to examine whether a multimodal, secondary prevention program (MP) is superior to a general physical exercise program (EP) in influencing the process leading to chronic low back pain (LBP) in nurses with a history of back pain. The study was conducted as a randomized controlled parallel-group trial. The interventions were performed in a single center at the Department of Physical and Rehabilitation Medicine at the University of Munich in Germany. A total of 235 nurses from 14 nearby hospitals and nursing homes who experienced at least one episode of back pain during the previous 2 years were invited into the study. Of these, 183 nurses were enrolled and 169 (83 in the MP and 86 in the EP) qualified for the intent-to-treat analysis. The EP consisted of 11 group sessions, each lasting 1 hour. After introductory sessions, subsequent sessions included general physical strengthening and stretching exercises as well as instructions for a home-training program. The MP consisted of 17 group sessions of 1.75 hours and one individual session of 45 minutes. In addition to the full EP, the MP included 5 psychological units, 7 segmental stabilization exercises units, and 8 ergonomic and workplace-specific units. The primary study end-point variable was pain interference, and the secondary study end-point variables were pain intensity and functioning as measured with the West Haven-Yale Multidimensional Pain Inventory and the Short Form-36, respectively. These study end-point variables were defined a priori. There was no statistically significant difference between the 2 groups. Small-to-moderate effects were observed in both intervention programs across all study end-point variables. For pain interference, the effect size at 12 months after intervention was 0.58 in the MP and 0.47 in the EP. A multimodal program is not superior to a general exercise program in influencing the process leading to chronic LBP in a population of nurses with a history

  9. Ultrasound guided, painful electrical stimulation of lumbar facet joint structures: an experimental model of acute low back pain.

    PubMed

    O'Neill, Søren; Graven-Nielsen, Thomas; Manniche, Claus; Arendt-Nielsen, Lars

    2009-07-01

    Quantitative sensory testing has indicated generalized muscle hyperalgesia in patients with chronic low back pain. The temporal development of such hyperalgesia is not well understood. The aim of the present study was to demonstrate whether generalized muscle hyperalgesia can develop within minutes of acute low back pain using a new experimental model of lumbar facet joint pain. Thirteen healthy volunteers were included and baseline pressure pain thresholds were assessed at eight separate sites, outside the area of evoked low back and referred pain. Using ultrasonography, two electrode needles were placed either side of a lumbar facet joint (right L3-4) and used to induce experimental low back pain for 10 min with continuous stimulation. Thresholds, stimulus-response relationships, distribution and quality of the electrically induced pain were recorded. Electrical facet joint stimulation induced low back pain and pain referral into the anterior leg, ipsilaterally, proximal to the knee, similar to what is observed clinically. Pressure pain thresholds did not change significantly before, during and after facet joint stimulation. In conclusion, we describe a novel model of acute experimental low back pain and demonstrate that generalized hyperalgesia did not develop within minutes of acute low back pain.

  10. Multisite, multimodal neuroimaging of chronic urological pelvic pain: Methodology of the MAPP Research Network.

    PubMed

    Alger, Jeffry R; Ellingson, Benjamin M; Ashe-McNalley, Cody; Woodworth, Davis C; Labus, Jennifer S; Farmer, Melissa; Huang, Lejian; Apkarian, A Vania; Johnson, Kevin A; Mackey, Sean C; Ness, Timothy J; Deutsch, Georg; Harris, Richard E; Clauw, Daniel J; Glover, Gary H; Parrish, Todd B; Hollander, Jan den; Kusek, John W; Mullins, Chris; Mayer, Emeran A

    2016-01-01

    The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP) Research Network is an ongoing multi-center collaborative research group established to conduct integrated studies in participants with urologic chronic pelvic pain syndrome (UCPPS). The goal of these investigations is to provide new insights into the etiology, natural history, clinical, demographic and behavioral characteristics, search for new and evaluate candidate biomarkers, systematically test for contributions of infectious agents to symptoms, and conduct animal studies to understand underlying mechanisms for UCPPS. Study participants were enrolled in a one-year observational study and evaluated through a multisite, collaborative neuroimaging study to evaluate the association between UCPPS and brain structure and function. 3D T1-weighted structural images, resting-state fMRI, and high angular resolution diffusion MRI were acquired in five participating MAPP Network sites using 8 separate MRI hardware and software configurations. We describe the neuroimaging methods and procedures used to scan participants, the challenges encountered in obtaining data from multiple sites with different equipment/software, and our efforts to minimize site-to-site variation.

  11. Duloxetine and Subacute Pain after Knee Arthroplasty when Added to a Multimodal Analgesic Regimen: A Randomized, Placebo-controlled, Triple-blinded Trial.

    PubMed

    YaDeau, Jacques T; Brummett, Chad M; Mayman, David J; Lin, Yi; Goytizolo, Enrique A; Padgett, Douglas E; Alexiades, Michael M; Kahn, Richard L; Jules-Elysee, Kethy M; Fields, Kara G; Goon, Amanda K; Gadulov, Yuliya; Westrich, Geoffrey

    2016-09-01

    Duloxetine is effective for chronic musculoskeletal and neuropathic pain, but there are insufficient data to recommend the use of antidepressants for postoperative pain. The authors hypothesized that administration of duloxetine for 15 days would reduce pain with ambulation at 2 weeks after total knee arthroplasty. In this triple-blinded, randomized, placebo-controlled trial, patients received either duloxetine or placebo for 15 days, starting from the day of surgery. Patients also received a comprehensive multimodal analgesic regimen including neuraxial anesthesia, epidural analgesia, an adductor canal block, meloxicam, and oxycodone/acetaminophen as needed. The primary outcome was the pain score (0 to 10 numeric rating scale) with ambulation on postoperative day 14. One hundred six patients were randomized and analyzed. On day 14, duloxetine had no effect on pain with ambulation; mean pain was 3.8 (SD, 2.3) for placebo versus 3.5 (SD, 2.1) for duloxetine (difference in means [95% CI], 0.4 [-0.5 to 1.2]; P = 0.386). Symptoms potentially attributable to duloxetine discontinuation at study drug completion (nausea, anxiety) occurred among nine patients (duloxetine) and five patients (placebo); this was not statistically significant (P = 0.247). Statistically significant secondary outcomes included opioid consumption (difference in mean milligram oral morphine equivalents [95% CI], 8.7 [3.3 to 14.1], P = 0.002 by generalized estimating equation) over the postoperative period and nausea on day 1 (P = 0.040). There was no difference in other side effects or in anxiety and depression scores. When included as a part of a multimodal analgesic regimen for knee arthroplasty, duloxetine does not reduce subacute pain with ambulation.

  12. Introducing the Geneva Multimodal expression corpus for experimental research on emotion perception.

    PubMed

    Bänziger, Tanja; Mortillaro, Marcello; Scherer, Klaus R

    2012-10-01

    Research on the perception of emotional expressions in faces and voices is exploding in psychology, the neurosciences, and affective computing. This article provides an overview of some of the major emotion expression (EE) corpora currently available for empirical research and introduces a new, dynamic, multimodal corpus of emotion expressions, the Geneva Multimodal Emotion Portrayals Core Set (GEMEP-CS). The design features of the corpus are outlined and justified, and detailed validation data for the core set selection are presented and discussed. Finally, an associated database with microcoded facial, vocal, and body action elements, as well as observer ratings, is introduced.

  13. Multimodal assessment of painful peripheral neuropathy induced by chronic oxaliplatin-based chemotherapy in mice

    PubMed Central

    2011-01-01

    Background A major clinical issue affecting 10-40% of cancer patients treated with oxaliplatin is severe peripheral neuropathy with symptoms including cold sensitivity and neuropathic pain. Rat models have been used to describe the pathological features of oxaliplatin-induced peripheral neuropathy; however, they are inadequate for parallel studies of oxaliplatin's antineoplastic activity and neurotoxicity because most cancer models are developed in mice. Thus, we characterized the effects of chronic, bi-weekly administration of oxaliplatin in BALB/c mice. We first studied oxaliplatin's effects on the peripheral nervous system by measuring caudal and digital nerve conduction velocities (NCV) followed by ultrastructural and morphometric analyses of dorsal root ganglia (DRG) and sciatic nerves. To further characterize the model, we examined nocifensive behavior and central nervous system excitability by in vivo electrophysiological recording of spinal dorsal horn (SDH) wide dynamic range neurons in oxaliplatin-treated mice Results We found significantly decreased NCV and action potential amplitude after oxaliplatin treatment along with neuronal atrophy and multinucleolated DRG neurons that have eccentric nucleoli. Oxaliplatin also induced significant mechanical allodynia and cold hyperalgesia, starting from the first week of treatment, and a significant increase in the activity of wide dynamic range neurons in the SDH. Conclusions Our findings demonstrate that chronic treatment with oxaliplatin produces neurotoxic changes in BALB/c mice, confirming that this model is a suitable tool to conduct further mechanistic studies of oxaliplatin-related antineoplastic activity, peripheral neurotoxicity and pain. Further, this model can be used for the preclinical discovery of new neuroprotective and analgesic compounds. PMID:21521528

  14. Does Addition of Multimodal Periarticular Analgesia to Adductor Canal Block Improve Lengths of Stay, Pain, Discharge Status, and Opioid Use After Total Knee Arthroplasty?

    PubMed

    Gwam, Chukwuweike U; Mistry, Jaydev B; Khlopas, Anton; Chughtai, Morad; Thomas, Melbin; Mont, Michael A; Delanois, Ronald E

    2017-05-01

    Postoperative pain after total knee arthroplasty (TKA) can be burdensome. Multiple methods of pain control have been used, including adductor canal block (ACB) and multimodal periarticular analgesia (MPA). These two techniques have been studied have proven to be efficacious separately. The purpose of this study was to compare: (1) lengths of stay (LOS), (2) pain level, (3) discharge status, and (4) opioid use in TKA patients who received ACB alone vs patients who received ACB and MPA. A single surgeon database was reviewed for patients who had a TKA between January 2015 and April 2016. Patients who received ACB with or without MPA were included. This yielded 127 patients who had a mean age of 63 years. Patients were grouped into having received ACB alone (n = 52) and having received ACB and MPA (n = 75). Patient records were reviewed to obtain demographic and end point data (LOS, pain, discharge status, and opioid use). Student t test and chi-squared test were used to compare continuous and categorical variables respectively. There were no significant difference in mean LOS (P = .934), pain level (P = .142), discharge status (P = .077), or total opioid use (P = .708) between the 2 groups. There was no significant difference in LOS, pain levels, discharge status, and opiate requirements between the 2 groups. ACB alone may be as effective as combined ACB and MPA in TKA patients for postoperative pain control. Larger prospective studies are needed to verify these findings and to improve generalization. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Effects of mindfulness and distraction on pain depend upon individual differences in pain catastrophizing: an experimental study.

    PubMed

    Prins, B; Decuypere, A; Van Damme, S

    2014-10-01

    The aim of this study was to investigate whether the perception of experimental pain was different during a mindfulness manipulation than during a distraction manipulation. Furthermore, it was examined if effects were moderated by dispositional pain catastrophizing. Undergraduate students (n = 51) completed self-report measures of pain catastrophizing and mindfulness. Subsequently, they were administered a series of mildly painful heat stimuli, which they had to rate. During pain induction, participants listened to either a pre-recorded mindfulness instruction (mindfulness group) or a pre-recorded story (distraction group). After controlling for baseline experimental pain ratings, we found no overall group effect, indicating that there was no difference in experienced pain between the mindfulness group and the distraction group. However, a significant moderation effect was found. When dispositional pain catastrophizing was high, pain was less pronounced in the mindfulness group than in the distraction group, whereas the opposite effect was found when the level of pain catastrophizing was low. The findings suggest that in persons with a high level of catastrophic thinking about pain, mindfulness-based coping may be a better approach than distraction. © 2014 European Pain Federation - EFIC®

  16. Assessing analgesic actions of opioids by experimental pain models in healthy volunteers – an updated review

    PubMed Central

    Staahl, Camilla; Olesen, Anne Estrup; Andresen, Trine; Arendt-Nielsen, Lars; Drewes, Asbjørn Mohr

    2009-01-01

    AIM Experimental pain models may help to evaluate the mechanisms of action of analgesics and target the clinical indications for their use. This review addresses how the efficacy of opioids can be assessed in human volunteers using experimental pain models. The drawback with the different study designs is also discussed. METHOD A literature search was completed for randomized controlled studies which included human experimental pain models, healthy volunteers and opioids. RESULTS Opioids with a strong affinity for the µ-opioid receptor decreased the sensation in a variety of experimental pain modalities, but strong tonic pain was attenuated more than short lasting pain and non-painful sensations. The effects of opioids with weaker affinity for the µ-opioid receptor were detected by a more narrow range of pain models, and the assessment methods needed to be more sensitive. CONCLUSION The way the pain is induced, assessed and summarized is very important for the sensitivity of the pain models. This review gives an overview of how different opioids perform in experimental pain models. Generally experimental pain models need to be designed with careful consideration of pharmacological mechanisms and pharmacokinetics of analgesics. This knowledge can aid the decisions needed to be taken when designing experimental pain studies for compounds entering phase 1 clinical trials. PMID:19694733

  17. Multimodal anesthesia with the addition of methadone is superior to epidural analgesia: A retrospective comparison of intraoperative anesthetic techniques and pain management for 124 pediatric patients undergoing the Nuss procedure.

    PubMed

    Singhal, Neil R; Jones, John; Semenova, Janet; Williamson, Amber; McCollum, Katelyn; Tong, Dennis; Jerman, Jonathan; Notrica, David M; Nguyen, Hayden

    2016-04-01

    The Nuss procedure corrects pectus excavatum by forceful displacement of the sternum with metal bars. Optimal pain management remains a challenge. Mutimodal anesthesia alleviates pain through blockade of multiple nociceptive and inflammatory pain receptors. A retrospective chart review of anesthetic and postoperative mangement of 125 children undergoing the Nuss procedure was conducted. Anesthetic mangement strategies were analyzed in four groups: opioid during general anesthesia (GA), epidural with general anesthesia (Epidural), multimodal anesthesia (MM), and multimodal anesthesia with methadone (MM+M). Data collection included total opioid use (as equivalent milligrams of morphine (Mmg)), pain scores, length of stay (LOS), and adverse effects. Total opioid use varied by group (median, IQR (in Mg)): Epidural 213 [149, 293], GA 179 [134, 298], MM (150 [123, 281]), and MM+M (106 [87, 149]), as did severe pain (in minutes): Epidural (208 [73, 323]), GA (115 [7, 255]), MM (54 [0, 210]), and MM+M (49 [0, 151]). LOS was shortest for the MM+M group (MM+M=3.8+1.0days; MM=4.5+1.3days; GA=4.9+1.4days, Epidural=5.5+2.3days). Multimodal anesthesia is associated with less postoperative pain and shorter LOS compared to epidural or traditional anesthetic techniques for the Nuss procedure. Multimodal anesthesia with a single intraoperative dose of methadone was associated with lowest total opioid use, time with uncontrolled pain, and shortest LOS. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. Experimental Pain Phenotype Profiles in a Racially and Ethnically Diverse Sample of Healthy Adults

    PubMed Central

    Cruz-Almeida, Yenisel; Riley, Joseph L.; Fillingim, Roger B.

    2014-01-01

    Objective To examine patterns of interindividual variability in experimental pain responses emerging from multiple experimental pain measures in a racially/ethnically diverse sample of healthy adults and to examine the association between the derived phenotype profiles with demographic, psychological, and health-related measures. Methods Two hundred and ninety-one participants underwent heat, cold, pressure, and ischemic pain assessments, and completed several psychological and health-related assessments. The experimental pain measures were subjected to a principal component analysis and factor scores were used to compute Pain Sensitivity Index scores. The scores were subsequently submitted to a cluster analysis to identify patterns of pain sensitivity across experimental pain modalities. Results The sample was equally composed of non-Hispanic whites, African Americans, and Hispanic whites. Sensitivity scores were computed for heat pain, pressure pain, cold pain, ischemic pain, and temporal summation of heat pain. Five distinct clusters were characterized by high heat pain sensitivity, low ischemic pain sensitivity, low cold pain sensitivity, low pressure pain sensitivity, and high temporal summation. Cluster membership was significantly different by sex as well as somatic reactivity and catastrophizing, although cluster differences were most pronounced between the heat pain-sensitive individuals vs the cold pain-insensitive individuals. Conclusions Our findings highlight the importance of phenotyping individuals to account for interindividual differences in pain responses. Our findings also replicate previously reported pain phenotypes, which are not solely related to demographic, psychosocial, or health-related factors in our healthy participants. Future studies designed to elucidate the biological underpinnings of pain sensitivity profiles would be of substantial value. PMID:23889771

  19. Suggestions to Reduce Clinical Fibromyalgia Pain and Experimentally Induced Pain Produce Parallel Effects on Perceived Pain but Divergent Functional MRI–Based Brain Activity

    PubMed Central

    Derbyshire, Stuart W.G.; Whalley, Matthew G.; Seah, Stanley T.H.; Oakley, David A.

    2017-01-01

    ABSTRACT Objective Hypnotic suggestion is an empirically validated form of pain control; however, the underlying mechanism remains unclear. Methods Thirteen fibromyalgia patients received suggestions to alter their clinical pain, and 15 healthy controls received suggestions to alter experimental heat pain. Suggestions were delivered before and after hypnotic induction with blood oxygen level–dependent (BOLD) activity measured concurrently. Results Across groups, suggestion produced substantial changes in pain report (main effect of suggestion, F2, 312 = 585.8; p < .0001), with marginally larger changes after induction (main effect of induction, F1, 312 = 3.6; p = .060). In patients, BOLD response increased with pain report in regions previously associated with pain, including thalamus and anterior cingulate cortex. In controls, BOLD response decreased with pain report. All changes were greater after induction. Region-of-interest analysis revealed largely linear patient responses with increasing pain report. Control responses, however, were higher after suggestion to increase or decrease pain from baseline. Conclusions Based on behavioral report alone, the mechanism of suggestion could be interpreted as largely similar regardless of the induction or type of pain experience. The functional magnetic resonance imaging data, however, demonstrated larger changes in brain activity after induction and a radically different pattern of brain activity for clinical pain compared with experimental pain. These findings imply that induction has an important effect on underlying neural activity mediating the effects of suggestion, and the mechanism of suggestion in patients altering clinical pain differs from that in controls altering experimental pain. Patient responses imply that suggestions altered pain experience via corresponding changes in pain-related brain regions, whereas control responses imply suggestion engaged cognitive control. PMID:27490850

  20. The Effects of Mindful Attention and State Mindfulness on Acute Experimental Pain Among Adolescents

    PubMed Central

    Chambers, Christine T.; Dick, Bruce D.

    2014-01-01

    Objective Attention-based coping strategies for pain are widely used in pediatric populations. The purpose of this study was to test a novel mindful attention manipulation on adolescent’s experimental pain responses. Furthermore, the relationship between state mindfulness and experimental pain was examined. Methods A total of 198 adolescents were randomly assigned to a mindful attention manipulation or control group prior to an experimental pain task. Participants completed measures of state mindfulness immediately prior to the pain task, and situational catastrophizing and pain intensity following the task. Results Overall the manipulation had no effect on pain. Secondary analysis showed that meditation experience moderated the effect of the manipulation. State mindfulness predicted pain outcomes, with reductions in situational catastrophizing mediating this relationship. Conclusions The mindful attention manipulation was effective among adolescents with a regular meditation practice. State mindfulness was related to ameliorated pain responses, and these effects were mediated by reduced catastrophizing. PMID:24599947

  1. Immediate effects and short-term retention of multi-modal instruction compared to written only on muscle activity during the prone horizontal abduction exercise in individuals with shoulder pain.

    PubMed

    Seitz, Amee L; Kocher, Jordan H; Uhl, Timothy L

    2014-10-01

    In rehabilitation, exercise instructions are multi-modal and can include a focus of increasing mean activity of a target muscle and inhibiting aberrant synergistic muscle activity, particularly during shoulder exercises, such as the prone horizontal abduction (PHA). The objective was to compare the immediate effects and short-term retention of multi-modal exercise instruction by a physical therapist written only instruction on normalized mean upper and lower trapezius muscle activity during three phases (concentric/isometric/eccentric) versus of an isotonic PHA exercise between participants with and without shoulder pain. Surface electromyography (EMG) was recorded from fourteen healthy participants and twelve participants with shoulder pain during the PHA exercise under two conditions: (1) written only instructions and (2) multi-modal instruction. Retention of multi-modal instruction on muscle activity was assessed one week later. Results demonstrate 12.8-16.0% increase in lower trapezius muscle activity during the concentric and isometric phases with multi-modal instructions in both groups. Inhibition of the upper trapezius did not occur in either group. Facilitation effects were maintained in short-term follow-up. Findings suggest that regardless of shoulder pain, multi-modal instruction by a physical therapist facilitates greater neuromuscular activity of a targeted muscle compared to written instructions alone and these effects are retained. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Experimental pain responses in children with chronic pain and in healthy children: How do they differ?

    PubMed Central

    Tsao, Jennie CI; Evans, Subhadra; Seidman, Laura C; Zeltzer, Lonnie K

    2012-01-01

    BACKGROUND: Extant research comparing laboratory pain responses of children with chronic pain with healthy controls is mixed, with some studies indicating lower pain responsivity for controls and others showing no differences. Few studies have included different pain modalities or assessment protocols. OBJECTIVES: To compare pain responses among 26 children (18 girls) with chronic pain and matched controls (mean age 14.8 years), to laboratory tasks involving thermal heat, pressure and cold pain. Responses to cold pain were assessed using two different protocols: an initial trial of unspecified duration and a second trial of specified duration. METHODS: Four trials of pressure pain and of thermal heat pain stimuli, all of unspecified duration, were administered, as well as the two cold pain trials. Heart rate and blood pressure were assessed at baseline and after completion of the pain tasks. RESULTS: Pain tolerance and pain intensity did not differ between children with chronic pain and controls for the unspecified trials. For the specified cold pressor trial, 92% of children with chronic pain completed the entire trial compared with only 61.5% of controls. Children with chronic pain exhibited a trend toward higher baseline and postsession heart rate and reported more anxiety and depression symptoms compared with control children. CONCLUSIONS: Contextual factors related to the fixed trial may have exerted a greater influence on pain tolerance in children with chronic pain relative to controls. Children with chronic pain demonstrated a tendency toward increased arousal in anticipation of and following pain induction compared with controls. PMID:22518373

  3. A practical guide and perspectives on the use of experimental pain modalities with children and adolescents

    PubMed Central

    Birnie, Kathryn A; Caes, Line; Wilson, Anna C; Williams, Sara E; Chambers, Christine T

    2014-01-01

    SUMMARY Use of experimental pain is vital for addressing research questions that would otherwise be impossible to examine in the real world. Experimental induction of pain in children is highly scrutinized given the potential for harm and lack of direct benefit to a vulnerable population. However, its use has critically advanced our understanding of the mechanisms, assessment and treatment of pain in both healthy and chronically ill children. This article introduces various experimental pain modalities, including the cold pressor task, the water load symptom provocation test, thermal pain, pressure pain and conditioned pain modulation, and discusses their application for use with children and adolescents. It addresses practical implementation and ethical issues, as well as the advantages and disadvantages offered by each task. The incredible potential for future research is discussed given the array of experimental pain modalities now available to pediatric researchers. PMID:24641434

  4. Nonverbal Communication as a Pain Reliever: The Impact of Physician Supportive Nonverbal Behavior on Experimentally Induced Pain.

    PubMed

    Ruben, Mollie A; Blanch-Hartigan, Danielle; Hall, Judith A

    2017-08-01

    Despite the evidence for the potential of supportive communication to alleviate physical pain, no study to date has assessed the impact of supportive nonverbal behavior on the objective and subjective experience of pain. This analogue study examined the impact of an actor-physician's supportive nonverbal behavior on experimentally induced pain. Participants (N = 205) were randomly assigned to interact with a videotaped physician conveying high or low supportive nonverbal behaviors. Participant pain was assessed with subjective and objective measures. Participants interacting with the high nonverbal support physicians showed increased pain tolerance and a reduction in the amount of pain expressed compared to those interacting with the low nonverbal support physicians. For subjectively rated pain, a gender difference existed such that for men, high physician nonverbal support decreased pain ratings and memory of pain, but for women, high physician nonverbal support increased pain ratings and memory of pain. These results highlight the importance of nonverbal communication in altering pain with broad implications for clinical care.

  5. Does a Multimodal No-Compression Suture Technique of the Intercostal Space Reduce Chronic Postthoracotomy Pain? A Prospective Randomized Study.

    PubMed

    Ibrahim, Mohsen; Menna, Cecilia; Andreetti, Claudio; Puyo, Carlos; Maurizi, Giulio; D'Andrilli, Antonio; Ciccone, Anna Maria; Massullo, Domenico; Vanni, Camilla; Berardi, Giammauro; Baldini, Rossella; Rendina, Erino Angelo

    2016-09-01

    Chronic postthoracotomy pain is a significant adverse outcome of thoracic surgery. We evaluated with a prospective randomized trial the effect of a multimodal no-compression suture technique of the intercostal space on postoperative pain occurrence in patients undergoing minithoracotomy. Patients undergoing a muscle-sparing lateral minithoracotomy for different thoracic diseases were randomly divided into two groups: 146 patients received intercostal muscle flap harvesting and pericostal no-compression "edge" suture (the IMF group), and 151 patients received a standard suture technique associated with an intrapleural intercostal nerve block (the IINB group). Pain scores and interference of pain with daily activities were assessed by using the Italian version of the Brief Pain Inventory on day 1, and at 1 to 6 months postoperatively. The results of pulmonary function tests (spirometry and the 6-minute walking test ) were evaluated preoperatively and at 1 and 6 months postoperatively. Postthoracotomy pain scores throughout the first postoperative day were significantly lower in the IMF group. After 1 and 6 months, patients in the IMF group had a significantly lower average pain score (p = 0.001). There were no significant differences in pain interference scores at each evaluation time point in either group. However, differences were shown in lung function test results at 1 and 6 months postoperatively (the forced expiratory volume in 1 second in the IINB group averaged 68.8 ± 17.4% of predicted value and 72.8 ± 10.5%, respectively, and in the IMF group it averaged 83.1 ± 7.4% and 86.4 ± 12.8%, respectively [p = 0.023 and 0.013, respectively]; the 6-minute walking test results in the IINB group averaged 311.1 ± 51.0 and 329.9 ± 54.8 m, respectively, and those in the IMF group averaged 371.2 ± 54.8 and 395.7 ± 56.4 m, respectively [p = 0.0001]). The multimodal no-compression suture technique is a rapid and feasible procedure that reduces the intensity of

  6. Pain perception in people with Down syndrome: a synthesis of clinical and experimental research

    PubMed Central

    McGuire, Brian E.; Defrin, Ruth

    2015-01-01

    People with an intellectual disability experience both acute and chronic pain with at least the same frequency as the general population. However, considerably less is known about the pain perception of people with Down syndrome. In this review paper, we evaluated the available clinical and experimental evidence. Some experimental studies of acute pain have indicated that pain threshold was higher than normal but only when using a reaction time method to measure pain sensitivity. However, when reaction time is not part of the calculation of the pain threshold, pain sensitivity in people with Down syndrome is in fact lower than normal (more sensitive to pain). Clinical studies of chronic pain have shown that people with an intellectual disability experience chronic pain and within that population, people with Down syndrome also experience chronic pain, but the precise prevalence of chronic pain in Down syndrome has yet to be established. Taken together, the literature suggests that people with Down syndrome experience pain, both acute and chronic, with at least the same frequency as the rest of the population. Furthermore, the evidence suggests that although acute pain expression appears to be delayed, once pain is registered, there appears to be a magnified pain response. We conclude by proposing an agenda for future research in this area. PMID:26283936

  7. Experimental reduction of pain catastrophizing modulates pain report but not spinal nociception as verified by mediation analyses.

    PubMed

    Terry, Ellen L; Thompson, Kathryn A; Rhudy, Jamie L

    2015-08-01

    Pain catastrophizing is associated with enhanced pain; however, the mechanisms by which it modulates pain are poorly understood. Evidence suggests that catastrophizing modulates supraspinal processing of pain but does not modulate spinal nociception (as assessed by nociceptive flexion reflex [NFR]). Unfortunately, most NFR studies have been correlational. To address this, this study experimentally reduced catastrophizing to determine whether it modulates spinal nociception (NFR). Healthy pain-free participants (N = 113) were randomly assigned to a brief 30-minute catastrophizing reduction manipulation or a control group that received pain education. Before and after manipulations, 2 types of painful stimuli were delivered to elicit (1) NFR (single trains of stimuli) and (2) temporal summation of NFR (3 stimulations at 2 Hz). After each set of stimuli, participants were asked to report their pain intensity and unpleasantness, as well as their situation-specific catastrophizing. Manipulation checks verified that catastrophizing was effectively reduced. Furthermore, pain intensity and unpleasantness to both stimulation types were reduced by the catastrophizing manipulation, effects that were mediated by catastrophizing. Although NFRs were not affected by the catastrophizing manipulation, temporal summation of NFR was reduced. However, this effect was not mediated by catastrophizing. These results indicate that reductions in catastrophizing lead to reductions in pain perception but do not modulate spinal nociception and provides further evidence that catastrophizing modulates pain at the supraspinal, not the spinal, level.

  8. Theoretical and Experimental Study of a Numerical Aperture for Multimode PCS Fiber Optics Using an Imaging Technique

    NASA Astrophysics Data System (ADS)

    Saman, Q. Mawlud; Nahlah, Q. Muhamad

    2012-11-01

    We study theoretically and experimentally the properties of numerical aperture (NA) of multimode graded-index plastic core silica (PCS) fibers by using an image technique. A He-Ne laser at wavelength 632.8 nm and output power 1 mW is used as the transmitter light source. The output beam images and intensity profiles of an optical fiber are investigated by using an imaging technique. The laser beam profiles captured by a sensitive digital Nikon camera are processed and analyzed by using a Gaussian intensity distribution in a 2D graph. A MathCAD 14 program is used for converting the image of the laser output beam into data. The theoretical and experimental values of the numerical aperture for the used optical fiber in this study are found to be 0.5 and 0.4924, respectively. The theoretical value of V-number is also calculated to be approximately 2482.

  9. Validation and application of a core set of patient-relevant outcome domains to assess the effectiveness of multimodal pain therapy (VAPAIN): a study protocol

    PubMed Central

    Kaiser, Ulrike; Kopkow, Christian; Deckert, Stefanie; Sabatowski, Rainer; Schmitt, Jochen

    2015-01-01

    Introduction Multimodal pain therapy (MPT) has been established accounting for biopsychosocial consideration in diagnostic and therapy. MPT seems to be effective, but comparability of studies is limited due to diversity of study designs and outcome measurements. The presented study aims to develop a core outcome set consisting of a minimum of outcome measures deemed necessary for medical and therapeutic decision-making, which must be measured in all clinical trials and non-randomised intervention studies. Methods and analysis The study consists of several parts. First, the development and recommendation of preliminary core outcome domains will be based on results of a systematic review and structured online surveys. Participants of the expert panel are representatives of methodological, medical, physiotherapeutic, psychotherapeutic profession and patients suffering from chronic pain (n=25). Subsequently, candidate instruments to measure preliminary core outcome domains will be recommended by these experts. Therefore, systematic reviews on measurement properties of preliminary outcome measures will be conducted and finalised in a consensus meeting. Consented instruments and lacking psychometric properties of relevant instruments will be addressed and validated in the following part, a prospective multicentre study in multimodal pain centres on approximately 300 patients with chronic pain. Based on all previous results, a core outcome set for MPT measured in effectiveness studies and daily recordkeeping will be finalised by consensus. Statistical analyses will be performed according to methodological standards (COSMIN). Ethics and dissemination The methods and procedure of the study are developed in compliance with the ethical principles of the Helsinki Declaration and Good Epidemiologic Practice. Recruitment of study participants will require approval of the study by the responsible ethics committee and signed informed consent from each participant. Pseudonymised

  10. Validation and application of a core set of patient-relevant outcome domains to assess the effectiveness of multimodal pain therapy (VAPAIN): a study protocol.

    PubMed

    Kaiser, Ulrike; Kopkow, Christian; Deckert, Stefanie; Sabatowski, Rainer; Schmitt, Jochen

    2015-11-06

    Multimodal pain therapy (MPT) has been established accounting for biopsychosocial consideration in diagnostic and therapy. MPT seems to be effective, but comparability of studies is limited due to diversity of study designs and outcome measurements. The presented study aims to develop a core outcome set consisting of a minimum of outcome measures deemed necessary for medical and therapeutic decision-making, which must be measured in all clinical trials and non-randomised intervention studies. The study consists of several parts. First, the development and recommendation of preliminary core outcome domains will be based on results of a systematic review and structured online surveys. Participants of the expert panel are representatives of methodological, medical, physiotherapeutic, psychotherapeutic profession and patients suffering from chronic pain (n=25). Subsequently, candidate instruments to measure preliminary core outcome domains will be recommended by these experts. Therefore, systematic reviews on measurement properties of preliminary outcome measures will be conducted and finalised in a consensus meeting. Consented instruments and lacking psychometric properties of relevant instruments will be addressed and validated in the following part, a prospective multicentre study in multimodal pain centres on approximately 300 patients with chronic pain. Based on all previous results, a core outcome set for MPT measured in effectiveness studies and daily recordkeeping will be finalised by consensus. Statistical analyses will be performed according to methodological standards (COSMIN). The methods and procedure of the study are developed in compliance with the ethical principles of the Helsinki Declaration and Good Epidemiologic Practice. Recruitment of study participants will require approval of the study by the responsible ethics committee and signed informed consent from each participant. Pseudonymised data will be used for statistical analysis. Published by the

  11. Cortical representation of experimental tooth pain in humans.

    PubMed

    Jantsch, H H F; Kemppainen, P; Ringler, R; Handwerker, H O; Forster, C

    2005-12-05

    Cortical processing of electrically induced pain from the tooth pulp was studied in healthy volunteers with fMRI. In a first experiment, cortical representation of tooth pain was compared with that of painful mechanical stimulation to the hand. The contralateral S1 cortex was activated during painful mechanical stimulation of the hand, whereas tooth pain lead to bilateral activation of S1. The S2 and insular region were bilaterally activated by both stimuli. In S2, the center of gravity of the activation during painful mechanical stimulation was more medial/posterior compared to tooth pain. In the insular region, tooth pain induced a stronger activation of the anterior and medial parts. The posterior part of the anterior cingulate gyrus was more strongly activated by painful stimulation of the hand. Differential activations were also found in motor and frontal areas including the orbital frontal cortex where tooth pain lead to greater activations. In a second experiment, we compared the effect of weak with strong tooth pain. A significantly greater activation by more painful tooth stimuli was found in most of those areas in which tooth pain had induced more activation than hand pain. In the medial frontal and right superior frontal gyri, we found an inverse relationship between pain intensity and BOLD contrast. We concluded that tooth pain activates a cortical network which is in several respects different from that activated by painful mechanical stimulation of the hand, not only in the somatotopically organized somatosensory areas but also in parts of the 'medial' pain projection system.

  12. Experimental and Theoretical Investigations on Stimulated Brillouin Scattering (SBS) in Multimode Fibers, at 1550 nm Wavelength

    DTIC Science & Technology

    2003-09-01

    determines a beam radius w,, which is equal to the second moment beam radius in the case of a Gaussian beam ( ISO 11146 :1999). The beam propagation...moments, M has to be corrected using the following formula (from ISO 11146 :1999): MA4 0.81 -1+1 (13) The siiilar correction should be done to obtain the...multimode fibers 3 . THEORETICAL MODEL I11o) -1 114 Fiber - " t "I. 5(L) 4/01 L Fig. 2 Schematic used to model the SBS interaction in the fiber The

  13. Pain modulatory phenotypes differentiate subgroups with different clinical and experimental pain sensitivity.

    PubMed

    Vaegter, Henrik B; Graven-Nielsen, Thomas

    2016-07-01

    Pain biomarkers are warranted for individualized pain management. Based on different pain modulatory phenotypes, the objectives of this study were to explore the existence of subgroups within patients with nonmalignant chronic pain and to investigate differences in clinical pain and pain hypersensitivity between subgroups. Cuff algometry was performed on lower legs in 400 patients with chronic pain to assess pressure pain threshold, pressure pain tolerance, temporal summation of pain (TSP: increase in pain scores to 10 repeated stimulations), and conditioned pain modulation (CPM: increase in cuff pressure pain threshold during cuff pain conditioning on the contralateral leg). Heat detection and heat pain thresholds at clinical painful and nonpainful body areas were assessed. Based on TSP and CPM, 4 distinct groups were formed: group 1 (n = 85) had impaired CPM and facilitated TSP; group 2 (n = 148) had impaired CPM and normal TSP; group 3 (n = 45) had normal CPM and facilitated TSP; and group 4 (n = 122) had normal CPM and normal TSP. Group 1 showed more pain regions than the other 3 groups (P < 0.001), indicating that impaired CPM and facilitated TSP play an important role in widespread pain. Groups 1 and 2 compared with group 4 had lower heat pain threshold at nonpainful areas and lower cuff pressure pain tolerance (P < 0.02), indicating that CPM plays a role for widespread hyperalgesia. Moreover, group 1 demonstrated higher clinical pain scores than group 4 (P < 0.05). Although not different between subgroups, patients were profiled on demographics, disability, pain catastrophizing, and fear of movement. Future research should investigate interventions tailored towards these subgroups.

  14. Experimental pain induces attentional bias that is modified by enhanced motivation: An eye tracking study.

    PubMed

    Sun, Z-K; Wang, J-Y; Luo, F

    2016-09-01

    In this study, the effects of prior pain experience and motivation on attentional bias towards pain-related information were investigated within two visual-probe tasks via eye movement behaviours. It is hypothesized that pain experience would induce stronger attentional bias and such bias could be suppressed by the motivation to avoid impeding pain. All participants took part in visual-probe tasks with pictures and words as stimuli that are typically used in studies of attentional bias. They were allocated to three groups: no-pain (NP) group, performing tasks without experiencing pain; pain-experience (PE) group, performing the same tasks following painful stimuli; and pain-experience-with-motivation (PEM) group, undergoing the same procedure as PE group with additional instructions about avoiding impeding pain. Eye movements were recorded during the tasks. The eye movement data showed that: (1) participants in the PE group exhibited stronger attention bias towards painful pictures than those in the NP group; (2) the attentional bias towards painful pictures was significantly reduced in the PEM group as compared to the PE group. By contrast, the verbal task failed to find these effects using sensory pain words as stimuli. This study was the first that revealed the impact of acute experimental pain on attentional bias towards pain-related information in healthy individuals through eye tracking. It may provide a possible solution to reduce hypervigilance towards pain-related information by altering the motivational relevance. WHAT DOES THIS STUDY ADD?: (1) This study revealed the impact of experimental pain on attentional bias in healthy individuals; (2) This study may provide a possible approach of altering motivational relevance to control the pain-induced attentional bias towards pain-related information. © 2016 European Pain Federation - EFIC®

  15. Identifying experimental methods to determine the effect of pain on attention: a review of pain, caffeine, alcohol and nicotine studies.

    PubMed

    Moore, David J; Keogh, Edmund; Eccleston, Christopher

    2009-12-01

    To review published studies of the effects that pain and common psychopharmacological substances have on the attentional performance of healthy adults. To identify which attentional tasks have the greatest potential to investigate the effect of pain on attention and provide recommendations for future research. A search was conducted for reports of experimental studies of attention in the context of pain. This was supplemented with studies on attention and caffeine, nicotine and alcohol. Studies were included if they used a healthy adult sample, used experimental or quasi-experimental methods, were relevant to the study of attention or interruption of pain and/or examined the acute effects of a substance on attention. Thirty-two papers, with 49 different experimental studies were identified (12 pain, 21 nicotine, 7 caffeine, 9 alcohol). Fourteen different tasks were reviewed across six domains of attention. The most promising measures of attention were the continuous performance task, flanker task, endogenous pre-cuing task, n-back task, inhibition task and dual task. There are reliable tasks that could be used to determine the effects of pain on attention. Future research is required that develops the utility of these tasks to improve our understanding of the effects pain and analgesia have on attentional performance. Copyright (c) 2009 John Wiley & Sons, Ltd.

  16. Ethnic Identity Predicts Experimental Pain Sensitivity In African Americans and Hispanics

    PubMed Central

    Rahim-Williams, F. Bridgett; Riley, Joseph L.; Herrera, Dyanne; Campbell, Claudia; Hastie, Barbara A.; Fillingim, Roger B.

    2007-01-01

    The aim of this study was to examine experimental pain sensitivity in three ethnic groups, African Americans, Hispanic Americans and non-Hispanic whites, and to determine whether ethnic identity is differentially associated with pain sensitivity across ethnic groups. Participants included sixty-three African American, sixty-one Hispanic and eighty-two non-Hispanic white participants who were assessed using three experimental pain measures: thermal, cold-pressor and ischemic. Participants’ ethnic identity was assessed using the Multi-group Ethnic Identity Measure (MEIM). Ethnic group differences in pain responses were observed, with African American and Hispanic subjects showing lower cold and heat pain tolerances than non-Hispanic whites. In addition, pain range (i.e. tolerance – threshold) was computed for heat, cold and ischemic pain, and the two minority groups again had lower values compared to non-Hispanic whites. Ethnic identity was associated with pain range only for African American and Hispanic groups. Statistically controlling for ethnic identity rendered some of the group differences in pain range non-significant. These findings indicate that ethnic identity is associated with pain sensitivity in ethnic minority groups, and may partially mediate group differences in pain perception. The results of the present investigation provide evidence of ethnic group differences in responses to experimental pain across multiple noxious stimuli, with both minority groups exhibiting greater sensitivity to laboratory evoked pain compared to non-Hispanic whites. PMID:17296267

  17. Sex differences in experimental pain among healthy children: a systematic review and meta-analysis.

    PubMed

    Boerner, Katelynn E; Birnie, Kathryn A; Caes, Line; Schinkel, Meghan; Chambers, Christine T

    2014-05-01

    Sex differences in response to experimental pain are commonly reported in systematic reviews in the adult literature. The objective of the present research was to conduct a systematic review and meta-analysis of sex differences in healthy children's responses to experimental pain (e.g., cold pressor, heat pain, pressure pain) and, where possible, to conduct analyses separately for children and adolescents. A search was conducted of electronic databases for published papers in English of empirical research using experimental pain tasks to examine pain-related outcomes in healthy boys and girls between 0 and 18 years of age. Eighty articles were eligible for inclusion and were coded to extract information relevant to sex differences. The systematic review indicated that, across different experimental pain tasks, the majority of studies reported no significant differences between boys and girls on pain-related outcomes. However, the meta-analysis of available combined data found that girls reported significantly higher cold pressor pain intensity compared to boys in studies where the mean age of participants was greater than 12 years. Additionally, a meta-analysis of heat pain found that boys had significantly higher tolerance than girls overall, and boys had significantly higher heat pain threshold than girls in studies where the mean age of participants was 12 years or younger. These findings suggest that developmental stage may be relevant for understanding sex differences in pain.

  18. Assessment of knee joint pain in experimental rodent models of osteoarthritis.

    PubMed

    Piel, Margaret J; Kroin, Jeffrey S; Im, Hee-Jeong

    2015-01-01

    Pain assessment in animal models of osteoarthritis is integral to interpretation of a model's utility in representing the clinical condition, and enabling accurate translational medicine. Here we describe two methods for behavioral pain assessments available for use in animal models of experimental osteoarthritic pain: Von Frey filaments and spontaneous activity monitoring.

  19. Efficacy and safety of PPC-5650 on experimental rectal pain in patients with irritable bowel syndrome.

    PubMed

    Nielsen, Lecia Møller; Olesen, Anne Estrup; Andresen, Trine; Simrén, Magnus; Törnblom, Hans; Drewes, Asbjørn Mohr

    2015-02-01

    PPC-5650 is a new pharmacological agent that can modulate acid-sensing ion channel activity, leading to a reduction in the pain signal under up-regulated conditions. The non-clinical programme for PPC-5650 supported a role for this novel agent in the treatment of pain in patients with irritable bowel syndrome (IBS). In patients with IBS, the aims of the study were: (1) to assess the efficacy of a single bolus of PPC-5650 locally applied in the rectum using multi-modal stimulations of the recto sigmoid and (2) to assess the safety profile of PPC-5650. The study was a randomized, double-blind, placebo-controlled, cross-over trial in patients with IBS, excluding females of child-bearing potential. The study consisted of a training visit, study visit 1 and 2 and a follow-up visit. Rectosigmoid electrical, thermal and mechanical stimulations were performed, pain perception was rated on a pain intensity scale and referred pain areas were assessed. All adverse events were registered. Twenty-five patients with IBS were enrolled and completed the study (9 women and 16 men; mean age 50.4 ± 12.7 years). No effects of the study drug were found on any of the rectal stimulations or for referred pain areas (all p > 0.05). No significant or clinically relevant treatment-related differences were seen for the laboratory safety variables or any other reported adverse event. In conclusion, in patients with IBS on rectal sensitivity to multi-modal stimulations, PPC-5650 did not produce efficacy relative to placebo. The overall safety and tolerability of PPC-5650 was acceptable.

  20. Experimental study on the statistic characteristics of a 3x3 RF MIMO channel over a single conventional multimode fiber.

    PubMed

    Lei, Yi; Li, Jianqiang; Wu, Rui; Fan, Yuting; Fu, Songnian; Yin, Feifei; Dai, Yitang; Xu, Kun

    2017-06-01

    Based on the observed random fluctuation phenomenon of speckle pattern across multimode fiber (MMF) facet and received optical power distribution across three output ports, we experimentally investigate the statistic characteristics of a 3×3 radio frequency multiple-input multiple-output (MIMO) channel enabled by mode division multiplexing in a conventional 50 µm MMF using non-mode-selective three-dimensional waveguide photonic lanterns as mode multiplexer and demultiplexer. The impacts of mode coupling on the MIMO channel coefficients, channel matrix, and channel capacity have been analyzed over different fiber lengths. The results indicate that spatial multiplexing benefits from the greater fiber length with stronger mode coupling, despite a higher optical loss.

  1. Experimental investigation of the compressible Richtmyer-Meshkov instability from a broad-spectrum, multimode initial perturbation

    SciTech Connect

    Farley, D.; Peyser, T.; Miller, P.; Logory, L.; Stry, P.; Burke, E., LLNL

    1997-11-01

    Experiments have been conducted using the Nova laser system to investigate the growth of the Richtmyer-Meshkov (RM) instability resuling from a strong shock wave (M{approximately}30) crossing a prescribed well-defined initial multimode perturbation. The perturbation was a 100 mode superposition of 1 {micro}m amplitude sine waves with randomly generated phases between 0 and 2{pi}. The two working fluids were fluidized brominated plastic and carbon resorcinol foam, giving a post-shock Atwood number of approximately 0.6. The present experimental results give a power-law coefficient of 0.87 {+-} 0.2 for the growth of the interface. This value is higher than results previously published.

  2. Mechanistic experimental pain assessment in computer users with and without chronic musculoskeletal pain.

    PubMed

    Ge, Hong-You; Vangsgaard, Steffen; Omland, Øyvind; Madeleine, Pascal; Arendt-Nielsen, Lars

    2014-12-06

    Musculoskeletal pain from the upper extremity and shoulder region is commonly reported by computer users. However, the functional status of central pain mechanisms, i.e., central sensitization and conditioned pain modulation (CPM), has not been investigated in this population. The aim was to evaluate sensitization and CPM in computer users with and without chronic musculoskeletal pain. Pressure pain threshold (PPT) mapping in the neck-shoulder (15 points) and the elbow (12 points) was assessed together with PPT measurement at mid-point in the tibialis anterior (TA) muscle among 47 computer users with chronic pain in the upper extremity and/or neck-shoulder pain (pain group) and 17 pain-free computer users (control group). Induced pain intensities and profiles over time were recorded using a 0-10 cm electronic visual analogue scale (VAS) in response to different levels of pressure stimuli on the forearm with a new technique of dynamic pressure algometry. The efficiency of CPM was assessed using cuff-induced pain as conditioning pain stimulus and PPT at TA as test stimulus. The demographics, job seniority and number of working hours/week using a computer were similar between groups. The PPTs measured at all 15 points in the neck-shoulder region were not significantly different between groups. There were no significant differences between groups neither in PPTs nor pain intensity induced by dynamic pressure algometry. No significant difference in PPT was observed in TA between groups. During CPM, a significant increase in PPT at TA was observed in both groups (P < 0.05) without significant differences between groups. For the chronic pain group, higher clinical pain intensity, lower PPT values from the neck-shoulder and higher pain intensity evoked by the roller were all correlated with less efficient descending pain modulation (P < 0.05). This suggests that the excitability of the central pain system is normal in a large group of computer users with low pain intensity

  3. Experimental investigation of the effect of multimodal inclined interface on Richtmyer-Meshkov instability evolution

    NASA Astrophysics Data System (ADS)

    Mohaghar, Mohammad; Carter, John; Musci, Benjamin; Ranjan, Devesh

    2016-11-01

    In the Georgia Tech Shock Tube and Advanced Mixing Laboratory, the evolution of Richtmyer-Meshkov instability (RMI) which arises from two initial conditions, namely, a predominantly single mode, inclined interface between two gases, and a perturbed, multimodal, inclined interface are studied. The gas combination of nitrogen-acetone as light gas and carbon dioxide as heavy gas (Atwood number of 0.23) with an inclination angle of 80 degrees (η/ λ = 0.097) was chosen in this set of experiments. The interface is visualized using planar laser diagnostics (simultaneous PLIF/PIV measurements), once impulsively accelerated by a Mach 1.55. The ensemble-averaged turbulence measurements of the density, velocity and density-velocity cross-statistics are used to investigate the effects of added secondary modes to the interface on the correlation between turbulence and mixing quantities.

  4. Optical fibre sensors based on multi-mode fibres and MIMO signal processing: an experimental approach

    NASA Astrophysics Data System (ADS)

    Ahrens, Andreas; Sandmann, Andre; Bremer, Kort; Roth, Bernhard; Lochmann, Steffen

    2015-09-01

    In this paper multiple-input multiple-output (MIMO) signal processing is investigated for fibre optic sensor applications. A (2 × 2) MIMO implementation is realized by using lower-order and higher-order mode groups of a graded-index (GI) multi-mode fibre (MMF) as separate transmission channels. A micro-bending pressure sensor changes these separate transmission characteristics and introduces additional crosstalk. By observing the weight-factors of the MIMO system the amount of load applied was determined. Experiments verified a good correlation between the change of the MIMO weight coefficients and the load applied to the sensor and thus verified that MIMO signal processing can beneficially be used for fibre optic sensor applications.

  5. Women with dysmenorrhea are hypersensitive to experimental deep muscle pain across the menstrual cycle.

    PubMed

    Iacovides, Stella; Baker, Fiona C; Avidon, Ingrid; Bentley, Alison

    2013-10-01

    Primary dysmenorrhea is a common painful condition in women that recurs every month across the reproductive years. The recurrent nociceptive input into the central nervous system that occurs during menstruation each month in women with dysmenorrhea is hypothesized to lead to increased sensitivity to painful stimuli. We investigated whether women with primary dysmenorrhea are hyperalgesic to deep muscle pain induced by a cleanly nociceptive method of hypertonic saline injection. Pain stimulation was applied both within an area of referred menstrual pain (lower back) and at a remote site outside of referred menstrual pain (forearm) in 12 healthy women with severe dysmenorrhea and 9 healthy women without dysmenorrhea, at 3 phases of the menstrual cycle: menstruation and follicular and luteal phases. Women rated their pain severity on a 100-mm visual analog scale every 30 seconds after injection until the pain subsided. In both groups of women, menstrual cycle phase had no effect on the reported intensity and duration of muscle pain. However, women with dysmenorrhea had increased sensitivity to experimental muscle pain both at the site of referred pain and at a remote nonpainful site, as assessed by peak pain severity visual analog scale rating, area under the visual analog scale curve, and pain duration, compared to women without dysmenorrhea. These data show that women with severe primary dysmenorrhea, who experience monthly menstrual pain, are hyperalgesic to deep muscle pain compared to women without dysmenorrhea. Our findings that dysmenorrheic women are hyperalgesic to a clinically relevant, deep muscle pain in areas within and outside of referred menstrual pain indicates lasting changes in pain sensitivity outside of the painful period during menstruation. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  6. Observational learning and pain-related fear: an experimental study with colored cold pressor tasks.

    PubMed

    Helsen, Kim; Goubert, Liesbet; Peters, Madelon L; Vlaeyen, Johan W S

    2011-12-01

    The primary aim of the current study was to experimentally test whether pain-related fear can be acquired through observational learning, whether extinction occurs after actual exposure to the aversive stimulus, and whether pain-related fear was associated with increased pain ratings. During an observation phase, female volunteers watched a video showing models performing cold pressor tasks (CPT), of which the color served as a conditioned stimulus (CS). In a differential fear conditioning paradigm, each of 2 colors were either paired with models' painful (CS+) or neutral (CS-) facial expressions. Exposure consisted of participants performing CPTs of both colors (10°C). Self-reported fear of pain and expected pain ratings were obtained after the observation period, while actual pain and avoidance measures were obtained during and after exposure. Results show that after observing another person performing the CPT associated with the painful faces, subjects report more fear of pain and expect more intense and unpleasant pain as compared with the CPT associated with the neutral faces. This effect of observational learning on pain-related fear persisted until after exposure. During and after exposure no stimulus-type effect for pain ratings was found. This study provides preliminary evidence for observational learning of pain-related fear in humans. Fear of pain can be more disabling than pain itself, and is a risk factor for chronic pain. Knowledge about the acquisition of pain-related fear may help to develop novel pain management programs. This study is one of the first to demonstrate the effects of observational learning on pain-related fear. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

  7. Human experimental pain models: A review of standardized methods in drug development

    PubMed Central

    Reddy, K. Sunil kumar; Naidu, M. U. R.; Rani, P. Usha; Rao, T. Ramesh Kumar

    2012-01-01

    Human experimental pain models are essential in understanding the pain mechanisms and appear to be ideally suited to test analgesic compounds. The challenge that confronts both the clinician and the scientist is to match specific treatments to different pain-generating mechanisms and hence reach a pain treatment tailored to each individual patient. Experimental pain models offer the possibility to explore the pain system under controlled settings. Standardized stimuli of different modalities (i.e., mechanical, thermal, electrical, or chemical) can be applied to the skin, muscles, and viscera for a differentiated and comprehensive assessment of various pain pathways and mechanisms. Using a multimodel-multistructure testing, the nociception arising from different body structures can be explored and modulation of specific biomarkers by new and existing analgesic drugs can be profiled. The value of human experimental pain models is to link animal and clinical pain studies, providing new possibilities for designing successful clinical trials. Spontaneous pain, the main compliant of the neuropathic patients, but currently there is no human model available that would mimic chronic pain. Therefore, current human pain models cannot replace patient studies for studying efficacy of analgesic compounds, although being helpful for proof-of-concept studies and dose finding. PMID:23626642

  8. The role of experimentally-induced subacromial pain on shoulder strength and throwing accuracy.

    PubMed

    Wassinger, Craig A; Sole, Gisela; Osborne, Hamish

    2012-10-01

    Shoulder injuries often comprise two separate yet related components, structural tissue damage and pain. The role of each of these components on shoulder function is difficult to ascertain. Experimental pain models allow the assessment of consequences of localized pain when applied to healthy individuals. By understanding the role of pain on shoulder function, clinicians will be able to more efficiently assess and treat shoulder injuries. The objective of the study was to evaluate the role of experimentally-induced sub-acromial pain on shoulder isokinetic rotational strength and throwing accuracy. This was a block counterbalanced, crossover, repeated measures study design utilizing 20 individuals without self-reported shoulder or cervical pathology. Shoulder function was measured with and without experimental pain injection (2 mL of 5% hypertonic saline) in the sub-acromial space. Functional tasks consisted of shoulder rotational strength utilizing isokinetic testing and throwing accuracy via the functional throwing performance index. The hypertonic saline induced moderate pain levels in all participants (4.3-5.1/10). Normalized shoulder internal (t = 3.76, p = 0.001) and external (t = 3.12, p = 0.006) rotation strength were both diminished in the painful condition compared to the pain free condition. Throwing accuracy was also reduced while the participants experienced pain (t = 3.99, p = 0.001). Moderate levels of experimental shoulder pain were sufficient to negatively influence shoulder strength and throwing accuracy in participants without shoulder pathology.

  9. Sex differences in parent and child pain ratings during an experimental child pain task.

    PubMed

    Moon, E C; Chambers, C T; Larochette, Anne-Claire; Hayton, K; Craig, K D; McGrath, P J

    2008-01-01

    Research in the field of pediatric pain has largely ignored the role of fathers in their children's pain experiences. The first objective of the present study was to examine the effect of the presence of mothers versus fathers on children's subjective ratings, facial expressions and physiological responses to acute pain. The second objective was to examine whether child and parent sex influence parents' proxy ratings of their children's pain. The final objective was to compare levels of agreement between mothers' and fathers' assessments of their children's pain. Participants included 73 children (37 boys, 36 girls), four to 12 years of age, along with 32 fathers and 41 mothers. Children undertook the cold pressor pain task while observed by one of their parents. During the task, the children's heart rates and facial expressions were recorded. Children provided self-reports and parents provided proxy reports of child pain intensity using the seven-point Faces Pain Scale. Neither child nor parent sex had a significant impact on children's subjective reports, facial expressions or heart rates in response to acute pain. Fathers gave their sons higher pain ratings than their daughters, whereas mothers' ratings of their sons' and daughters' pain did not differ. Kappa statistics and t tests revealed that fathers tended to be more accurate judges of their children's pain than mothers. Overall, this research highlights the importance of examining both parent and child sex differences in pediatric pain research.

  10. Multimodal physical therapy management of a 48-year-old female with post-stroke complex regional pain syndrome.

    PubMed

    Anandkumar, Sudarshan; Manivasagam, Murugavel

    2014-01-01

    This case report describes a 48-year-old female who presented with complaints of right shoulder pain, hyperesthesias and swelling of the hand along with added symptoms of pain centralization following a cerebrovascular accident. On clinical evaluation, the patient satisfied the Budapest diagnostic criteria for Complex Regional Pain Syndrome (CRPS) type-1. Physical therapy management (1st three sessions) was initially focused on pain neurophysiology education with an aim to reduce kinesiophobia and reconceptualise her pain perception. The patient had an immediate significant improvement in her pain and functional status. Following this, pain modulation in the form of transcutaneous electrical nerve stimulation, kinesio tape application, "pain exposure" physical therapy and exercise therapy was carried out for a period of 7 weeks. The patient had complete resolution of her symptoms which was maintained at a six-month follow-up.

  11. In Vivo praying and catastrophizing mediate the race differences in experimental pain sensitivity.

    PubMed

    Meints, Samantha M; Hirsh, Adam T

    2015-05-01

    Black individuals have a lower tolerance for experimental pain than white individuals. Black and white individuals also differ in their use of pain coping strategies, which may explain the race differences in pain sensitivity. We examined the extent to which situation-specific pain coping mediated black-white differences in pain sensitivity. We hypothesized that 1) black participants would demonstrate lower pain tolerance than white participants, 2) black participants would use different pain coping strategies than white participants, and 3) the differential use of these strategies would mediate the relationship between race and pain tolerance. Healthy college undergraduates (N = 190) participated in a cold pressor task and then completed the Coping Strategies Questionnaire-Revised to assess their situation-specific pain coping. Compared with white participants, black participants demonstrated lower pain tolerance, engaged in more situation-specific catastrophizing and praying, and ignored pain less frequently. Catastrophizing and praying were inversely related to pain tolerance and were significant mediators of the relationship between race and pain tolerance. The indirect effect of praying was stronger than that of catastrophizing. Race differences in pain sensitivity may be due, in part, to differences in the use of catastrophizing and praying as coping strategies. These results may help guide treatments addressing maladaptive pain coping. This study suggests that race differences in pain sensitivity may be due, in part, to the differential use of catastrophizing and praying strategies. Psychosocial treatments for pain should encourage patients to take an active role in their pain management. Copyright © 2015 American Pain Society. Published by Elsevier Inc. All rights reserved.

  12. Nurses' response to pain communication from patients: a post-test experimental study.

    PubMed

    McDonald, Deborah Dillon; Laporta, Matthew; Meadows-Oliver, Mikki

    2007-01-01

    Inadequate communication about pain can result in increased pain for patients. The purpose of the current pilot study was to test how nurses respond when patients use their own words, a pain intensity scale, or both to communicate pain. A post-test only experimental design was used with three pain description conditions, personal and numeric; personal only; numeric only. The setting included six hospitals and one school of nursing located in the northeastern United States. PARTICIPANTS included 122 registered medical surgical nurses. Nurses were randomly assigned to condition, and read a vignette about a trauma patient with moderately severe pain. The vignettes were identical except for the patient's pain description and age. The nurses then wrote how they would respond to the patient's pain. Two blind raters content analyzed the responses, giving nurses one point for including each of six a priori criteria derived from the Acute Pain Management Panel [1992. Acute Pain Management: operative or medical procedures and trauma. Clinical practice guideline (AHCPR Publication No. 92-0032)., Rockville, MD, USA] and the American Pain Society [2003. Principles of analgesic use in the treatment of acute pain and cancer pain, Glenville, IL, USA]. Nurses planned similar numbers of pain management strategies across the three conditions, with a mean of 2.1 (SD=1.14) strategies out of the recommended six. Nurses did not respond with more pain management strategies when patients describe pain in their own words, or in their own words and a pain intensity scale. The relatively small number of pain management strategies planned by the nurses suggests that nurses use few strategies to respond to moderately severe pain problems.

  13. Effects of coping statements on experimental pain in chronic pain patients.

    PubMed

    Roditi, Daniela; Robinson, Michael E; Litwins, Nola

    2009-08-19

    The present study measured the effects of catastrophizing self-statements and positive coping self-statements on cold pressor-induced pain. Participants were 58 adult chronic pain patients with current facial pain. It was hypothesized that catastrophizing would lead to a decrease in pain endurance whereas positive coping would lead to an increase in pain endurance. It was also hypothesized that catastrophizing would lead to an increase in peak pain intensity whereas positive coping would lead to a decrease in peak pain intensity. At pretest, participants submerged their nondominant hand in the cold pressor. Pain sensitivity ranges (PSR) were subsequently determined by calculating the difference between tolerance and threshold times. Ratings of peak pain intensity were measured using a pressure sensitive bladder/transducer. Participants underwent random assignment to either a catastrophizing group or a positive coping self-statement group. ANCOVA results revealed that on average, participants employing catastrophizing statements as a coping strategy experienced significantly lower PSR (M = 35.53, SD = 39.71) compared to participants employing positive coping self-statements (M = 73.70, SD = 86.14) when controlling for pretest PSR. Group assignment had no significant influence on peak pain intensity ratings. Thus, our results reveal that manipulation of coping causes changes in pain endurance.

  14. Relationships among Eysenck's extraversion, Rorschach's Erlebnistypus, and tolerance of experimental tonic pain (Cold Water Pressor Test).

    PubMed

    Ferracuti, Stefano; De Carolis, Antonella

    2005-02-01

    In a group of 42 healthy volunteers the correlations between the concept of Extraversion-Introversion as defined by Eysenck and Erlebnistypus as defined by Rorschach were analysed to relate these with the tolerance of an experimentally induced tonic pain. We conducted an experimental procedure comprising a test and retest. At test the subjects were administered the Rorschach, the Eysenck Personality Inventory, the Cold Water Pressor Test, a nongraduated Visual Analogue Scale, and the Italian version of the McGill Pain Questionnaire. At retest the experimental induction of pain was measured again. At test subjects who scored higher on the EPI Extraversion scale tolerated pain longer and did not modify their performance at retest. Also, the concepts of Extroversion defined by the Rorschach test and by the Extraversion scale of the Eysenck Personality Inventory shared some psychophysiological features of higher tolerance to pain. These personality features did not influence how subjects qualitatively describe the immediate painful experience.

  15. An experimental investigation of the effects of preferred and relaxing music listening on pain perception.

    PubMed

    Mitchell, Laura A; MacDonald, Raymond A R

    2006-01-01

    This study investigates the effects of music listening on perception and tolerance of experimentally induced cold pressor pain. Fifty-four participants (34 females, 20 males) each underwent 3 cold pressor trials while listening to (a) white noise, (b) specially designed relaxation music, and (c) their own chosen music. Tolerance time, pain intensity on visual analog scale, and the pain rating index of the McGill Pain Questionnaire and perceived control over the pain were measured in each condition. While listening to their own preferred music, male and female participants tolerated the painful stimulus significantly longer than during both the relaxation music and control conditions. However, only female participants rated the intensity of the pain as significantly lower in the preferred music condition. Both male and female participants reported feeling significantly more control when listening to their preferred music. It is suggested that personal preference is an influential factor when considering the efficacy of music listening for pain relief.

  16. Experimental knee pain impairs submaximal force steadiness in isometric, eccentric, and concentric muscle actions.

    PubMed

    Rice, David A; McNair, Peter J; Lewis, Gwyn N; Mannion, Jamie

    2015-09-12

    Populations with knee joint damage, including arthritis, have noted impairments in the regulation of submaximal muscle force. It is difficult to determine the exact cause of such impairments given the joint pathology and associated neuromuscular adaptations. Experimental pain models that have been used to isolate the effects of pain on muscle force regulation have shown impaired force steadiness during acute pain. However, few studies have examined force regulation during dynamic contractions, and these findings have been inconsistent. The goal of the current study was to examine the effect of experimental knee joint pain on submaximal quadriceps force regulation during isometric and dynamic contractions. The study involved fifteen healthy participants. Participants were seated in an isokinetic dynamometer. Knee extensor force matching tasks were completed in isometric, eccentric, and concentric muscle contraction conditions. The target force was set to 10 % of maximum for each contraction type. Hypertonic saline was then injected into the infrapatella fat pad to generate acute joint pain. The force matching tasks were repeated during pain and once more 5 min after pain had subsided. Hypertonic saline resulted in knee pain with an average peak pain rating of 5.5 ± 2.1 (0-10 scale) that lasted for 18 ± 4 mins. Force steadiness significantly reduced during pain across all three muscle contraction conditions. There was a trend to increased force matching error during pain but this was not significant. Experimental knee pain leads to impaired quadriceps force steadiness during isometric, eccentric, and concentric contractions, providing further evidence that joint pain directly affects motor performance. Given the established relationship between submaximal muscle force steadiness and function, such an effect may be detrimental to the performance of tasks in daily life. In order to restore motor performance in people with painful arthritic conditions of the

  17. [Efficacy of epidural steroid injections for chronic lumbar pain syndromes without neurological deficits. A randomized, double blind study as part of a multimodal treatment concept].

    PubMed

    Niemier, K; Schindler, M; Volk, T; Baum, K; Wolf, B; Eberitsch, J; Seidel, W

    2015-07-01

    Chronic lumbar pain syndromes without neurological deficits are generated by a multitude of causes. Functional, morphological and psychosocial factors are discussed. In many cases a diseased intervertebral disc is found on radiological examination but the clinical relevance of these findings is not clear. For this study it was postulated that a diseased disc results in a local inflammatory reaction therefore causing pain and impairing treatability of patients. An epidural injection of steroids can reduce inflammation and therefore improve treatability and ultimately treatment outcome. A double blind randomized prospective trial was carried out. Patients treated in hospital for a chronic lumbar pain syndrome without neurological deficits within a multimodal treatment program were screened for indications for an epidural steroid injection (e.g. diseased lumbar disc and intention to treat). Patients eligible for the study were randomized into two groups. The treatment group received an epidural injection of 80 mg triamcinolone and 8 ml bupivacaine 0.25 %. The control group received only an epidural injection of 8 ml bupivacaine 0.25 %. In both groups pain intensity and treatability showed a statistically significant improvement after the epidural injection. The differences between the control and treatment groups were small and not clinically relevant. A small subgroup might profit from the steroid injection. In addition the treatability was dependent on psychometric values and the long-term outcome from a reduction of muscular skeletal dysfunctions. After the epidural injection the decrease in pain and increase in treatability was statistically significant. The mechanism of the improvement is not clear and should be examined further. The epidural injection of a steroid in this subgroup of patients did not lead to a clinical improvement in the outcome.

  18. Periodontal CGRP contributes to orofacial pain following experimental tooth movement in rats.

    PubMed

    Long, Hu; Liao, Lina; Gao, Meiya; Ma, Wenqiang; Zhou, Yang; Jian, Fan; Wang, Yan; Lai, Wenli

    2015-08-01

    Calcitonin-related gene peptide (CGRP) plays an important role in orofacial inflammatory pain. The aim of this study was to determine whether periodontal CGRP contributes to orofacial pain induced by experimental tooth movement in rats. Male Sprague-Dawley rats were used in this study. Closed coil springs were used to deliver forces. Rats were euthanized on 0d, 1d, 3d, 5d, 7d, and 14d following experimental tooth movement. Then, alveolar bones were obtained for immunostaining of periodontal tissues against CGRP. Two hours prior to euthanasia on each day, orofacial pain levels were assessed through rat grimace scale. CGRP and olcegepant (CGRP receptor antagonist) were injected into periodontal tissues to verify the roles of periodontal CGRP in orofacial pain induced by experimental tooth movement. Periodontal CGRP expression levels and orofacial pain levels were elevated on 1d, 3d, 5d, and 7d following experimental tooth movement. The two indices were significantly correlated with each other and fitted into a dose-response model. Periodontal administration of CGRP could elevate periodontal CGRP expressions and exacerbate orofacial pain. Moreover, olcegepant administration could decrease periodontal CGRP expressions and alleviate orofacial pain. Therefore, periodontal CGRP plays an important role in pain transmission and modulation following experimental tooth movement. We suggest that it may participate in a positive feedback aiming to amplify orofacial pain signals.

  19. Multimodal imaging with hybrid semiconductor detectors Timepix for an experimental MRI-SPECT system

    NASA Astrophysics Data System (ADS)

    Zajicek, J.; Jakubek, J.; Burian, M.; Vobecky, M.; Fauler, A.; Fiederle, M.; Zwerger, A.

    2013-01-01

    An increasing number of clinical applications are being based on multimodal imaging systems (MIS), including anatomical (CT, MRI) and functional (PET, SPECT) techniques to provide complex information in a single image. CT with one of the scintigraphic methods (PET or SPECT) is nowadays a combination of choice for clinical practice and it is mostly used in cardiography and tumour diagnostics. Combination with MRI is also being implemented as no radiation dose is imparted to the patient and it is possible to gain higher structural resolution of soft tissues (brain imaging). A major disadvantage of such systems is inability to operate scintillators with photomultipliers (used for detection of γ rays) in presence of high magnetic fields. In this work we present the application of the semiconductor pixel detector for SPECT method in combination with MR imaging. We propose a novel approach based on MRI compatible setup with CdTe pixel sensor Timepix and non-conductive collimator. Measurements were performed on high proton-density (PD) phantom (1H) with an embedded radioisotopic source inside the shielded RF coil by MRI animal scanner (4.7 T). Our results pave the way for a combined MRI-SPECT system. The project was performed in the framework of the Medipix Collaboration.

  20. Sex, Gender, and Pain: A Review of Recent Clinical and Experimental Findings

    PubMed Central

    Fillingim, Roger B.; King, Christopher D.; Ribeiro-Dasilva, Margarete C.; Rahim-Williams, Bridgett; Riley, Joseph L.

    2009-01-01

    Sex-related influences on pain and analgesia have become a topic of tremendous scientific and clinical interest, especially in the last 10 to 15 years. Members of our research group published reviews of this literature more than a decade ago, and the intervening time period has witnessed robust growth in research regarding sex, gender, and pain. Therefore, it seems timely to revisit this literature. Abundant evidence from recent epidemiologic studies clearly demonstrates that women are at substantially greater risk for many clinical pain conditions, and there is some suggestion that postoperative and procedural pain may be more severe among women than men. Consistent with our previous reviews, current human findings regarding sex differences in experimental pain indicate greater pain sensitivity among females compared with males for most pain modalities, including more recently implemented clinically relevant pain models such as temporal summation of pain and intramuscular injection of algesic substances. The evidence regarding sex differences in laboratory measures of endogenous pain modulation is mixed, as are findings from studies using functional brain imaging to ascertain sex differences in pain-related cerebral activation. Also inconsistent are findings regarding sex differences in responses to pharmacologic and non-pharmacologic pain treatments. The article concludes with a discussion of potential biopsychosocial mechanisms that may underlie sex differences in pain, and considerations for future research are discussed. Perspective This article reviews the recent literature regarding sex, gender, and pain. The growing body of evidence that has accumulated in the past 10 to 15 years continues to indicate substantial sex differences in clinical and experimental pain responses, and some evidence suggests that pain treatment responses may differ for women versus men. PMID:19411059

  1. Antihyperalgesic effect of pentoxifylline on experimental inflammatory pain

    PubMed Central

    Vale, Mariana L; Benevides, Verônica M; Sachs, Daniela; Brito, Gerly A C; da Rocha, Francisco A C; Poole, Stephen; Ferreira, Sérgio H; Cunha, Fernando Q; Ribeiro, Ronaldo A

    2004-01-01

    The antihyperalgesic effect of pentoxifylline was investigated in three experimental pain models. Pentoxifylline (0.5–1.6 mg kg−1) given 30 min before the stimulus significantly inhibited the writhing response induced by the intraperitoneal (i.p.) administration of either acetic acid (−90%) or zymosan (−83%), but not that of iloprost, in mice, as well as the zymosan-induced articular hyperalgesia in the zymosan arthritis in rats (−50%). Pentoxifylline also inhibited the mechanical hypernociception in rats induced by the intraplantar injection of either carrageenin (−81%), bradykinin (−56%) or tumor necrosis factor α (TNF-α; −46%), but not that induced by interleukin-1β (IL-1β) or prostaglandin E2 (PGE2). Pentoxifylline did not inhibit the nociceptive response in the hot plate test in mice. Further, the antinociceptive effect of pentoxifylline in the writhing test in mice and the zymosan-induced articular hyperalgesia were not reversed by the coadministration of the opioid receptor antagonist naloxone. Thus, pentoxifylline antinociceptive effect is probably not mediated at a central level. Pentoxifylline significantly reduced TNF-α (−43%) and IL-1β (−42%) concentrations in the joint exudates of rats stimulated by intra-articular injection of zymosan and the production of both cytokines (−66 and −86%, respectively) by mouse peritoneal macrophages stimulated in vivo with zymosan as well as the expression of TNF-α at the tissue level in carrageenin-injected rat paws. In conclusion, the antinociceptive activity of pentoxifylline is associated with the inhibition of the release of both TNF-α and IL-1β. PMID:15520047

  2. Antihyperalgesic effect of pentoxifylline on experimental inflammatory pain.

    PubMed

    Vale, Mariana L; Benevides, Verônica M; Sachs, Daniela; Brito, Gerly A C; da Rocha, Francisco A C; Poole, Stephen; Ferreira, Sérgio H; Cunha, Fernando Q; Ribeiro, Ronaldo A

    2004-12-01

    The antihyperalgesic effect of pentoxifylline was investigated in three experimental pain models. Pentoxifylline (0.5-1.6 mg kg(-1)) given 30 min before the stimulus significantly inhibited the writhing response induced by the intraperitoneal (i.p.) administration of either acetic acid (-90%) or zymosan (-83%), but not that of iloprost, in mice, as well as the zymosan-induced articular hyperalgesia in the zymosan arthritis in rats (-50%). Pentoxifylline also inhibited the mechanical hypernociception in rats induced by the intraplantar injection of either carrageenin (-81%), bradykinin (-56%) or tumor necrosis factor alpha (TNF-alpha; -46%), but not that induced by interleukin-1beta (IL-1beta) or prostaglandin E(2) (PGE(2)). Pentoxifylline did not inhibit the nociceptive response in the hot plate test in mice. Further, the antinociceptive effect of pentoxifylline in the writhing test in mice and the zymosan-induced articular hyperalgesia were not reversed by the coadministration of the opioid receptor antagonist naloxone. Thus, pentoxifylline antinociceptive effect is probably not mediated at a central level. Pentoxifylline significantly reduced TNF-alpha (-43%) and IL-1beta (-42%) concentrations in the joint exudates of rats stimulated by intra-articular injection of zymosan and the production of both cytokines (-66 and -86%, respectively) by mouse peritoneal macrophages stimulated in vivo with zymosan as well as the expression of TNF-alpha at the tissue level in carrageenin-injected rat paws. In conclusion, the antinociceptive activity of pentoxifylline is associated with the inhibition of the release of both TNF-alpha and IL-1beta.

  3. Empathy Predicts an Experimental Pain Reduction During Touch.

    PubMed

    Goldstein, Pavel; Shamay-Tsoory, Simone G; Yellinek, Shahar; Weissman-Fogel, Irit

    2016-10-01

    Previous studies have provided evidence for pain-alleviating effects of segmental tactile stimulation, yet the effect of social touch and its underlying mechanism is still unexplored. Considering that the soma affects the way we think, feel, and interact with others, it has been proposed that touch may communicate emotions, including empathy, interacting with the identity of the toucher. Thus, the goal of the current study was to examine the analgesic effects of social touch, and to test the moderating role of the toucher's empathy in analgesia using an ecological paradigm. Tonic heat stimuli were administered to women. Concurrently, their partners either watched or touched their hands, a stranger touched their hands, or no one interacted with them. The results revealed diminished levels of pain during partners' touch compared with all other control conditions. Furthermore, taking into account the dyadic interaction, only during the touch condition we found 1) a significant relationship between the partners' pain ratings, and 2) a significant negative relationship between the male touchers' empathy and the pain experience of their female partners. The findings highlight the powerful analgesic effect of social touch and suggest that empathy between romantic partners may explain the pain-alleviating effects of social touch. Pain research mostly concentrates on different factors around a single pain target, without taking into account various social interactions with the observers. Our findings support the idea that pain perception models should be extended, taking into account some psychological characteristics of observers. Our conclusions are on the basis of advanced statistical methods. Copyright © 2016 American Pain Society. Published by Elsevier Inc. All rights reserved.

  4. Role of gender norms and group identification on hypothetical and experimental pain tolerance.

    PubMed

    Pool, Gregory J; Schwegler, Andria F; Theodore, Brian R; Fuchs, Perry N

    2007-05-01

    Previous research indicates that men typically tolerate more pain in experimental settings than women. One likely explanation for these group differences in pain tolerance is conformity to traditional, gender group social norms (i.e., the ideal man is masculine and tolerates more pain; the ideal woman is feminine and tolerates less pain). According to self-categorization theory, norms guide behavior to the degree that group members adopt the group identity. Therefore, high-identifying men are expected to conform to gender norms and tolerate more pain than high-identifying women who conform to different gender norms as a guide for their behavior. We conducted two studies to investigate whether gender group identification moderates individuals' conformity to pain tolerance and reporting norms. In the first study, participants indicated their gender identification and expected tolerance of a hypothetical painful stimulus. As anticipated, high-identifying men reported significantly greater pain tolerance than high-identifying women. No differences existed between low-identifying men and women. To determine if self-reported pain tolerance in a role-playing scenario corresponds to actual pain tolerance in an experimental setting, the second study examined pain tolerance to a noxious stimulus induced by electrical stimulation of the index finger. The experimental outcome revealed that high-identifying men tolerated more painful stimulation than high-identifying women. Further, high-identifying men tolerated more pain than low-identifying men. These results highlight the influence of social norms on behavior and suggest the need to further explore the role of norms in pain reporting behaviors.

  5. Pre-emptive injection of peri-articular-multimodal drug for post-operative pain management in total knee arthroplasty: a double-blind randomized clinical trial.

    PubMed

    Motififard, Mahdi; Omidian, Ali; Badiei, Sajad

    2017-05-01

    Severe post-operative pain is one of the main problems after total knee arthroplasty. In this study, we investigated the effect of a peri-articular multimodal drugs injections pre-emptively on post-operative pain control and knee functions following total knee arthroplasty. This study was a double-blind randomized clinical trial. Eligible cases including 137 patients-aged 30 to 80 years old-were randomly divided into one of two groups: the drug group received a cocktail consisting of bupivacaine hydrochloride, morphine sulphate, epinephrine, and ketorolac. The control group received epinephrine only. The injections were given 15 minutes before incision. Joint range of motion (ROM) and the severity of pain by using visual analog scale (VAS) of 1 to 10 and patient's facial expression, were assessed in the pre-operative visit, after 24 hours, 48 hours, and six weeks after operation. Knee Society score (KSS) was recorded before the operation, six weeks, and six months after the operation for each patient. The data of VAS showed no significant difference between the groups before operation but there was statistically significant difference between the two groups at 24 hours, 48 hours, and six weeks after the operation. In KSS, difference was not significant between the two groups before the operation and six months after surgery while our results showed a statistically significant difference between groups six weeks after the operation. In ROM, there was no significant difference between the groups before operation. There was a statistically significant difference between the two groups at 24 hours, 48 hours and six weeks after the operation. Complications were recorded at six weeks after surgery. Peri-articular multimodal injection including bupivacaine, morphine, and ketorolac preferably with pre-emptive injection method provided proper post-operative pain relief, less opioid consumption, and better early rehabilitation following TKA at 48 hours after

  6. Experimental pain processing in individuals with cognitive impairment: current state of the science.

    PubMed

    Defrin, Ruth; Amanzio, Martina; de Tommaso, Marina; Dimova, Violeta; Filipovic, Sasa; Finn, David P; Gimenez-Llort, Lydia; Invitto, Sara; Jensen-Dahm, Christina; Lautenbacher, Stefan; Oosterman, Joukje M; Petrini, Laura; Pick, Chaim G; Pickering, Gisele; Vase, Lene; Kunz, Miriam

    2015-08-01

    Cognitive impairment (CI) can develop during the course of ageing and is a feature of many neurological and neurodegenerative diseases. Many individuals with CI have substantial, sustained, and complex health care needs, which frequently include pain. However, individuals with CI can have difficulty communicating the features of their pain to others, which in turn presents a significant challenge for effective diagnosis and treatment of their pain. Herein, we review the literature on responsivity of individuals with CI to experimental pain stimuli. We discuss pain responding across a large number of neurological and neurodegenerative disorders in which CI is typically present. Overall, the existing data suggest that pain processing is altered in most individuals with CI compared with cognitively intact matched controls. The precise nature of these alterations varies with the type of CI (or associated clinical condition) and may also depend on the type of pain stimulation used and the type of pain responses assessed. Nevertheless, it is clear that regardless of the etiology of CI, patients do feel noxious stimuli, with more evidence for hypersensitivity than hyposensitivity to these stimuli compared with cognitively unimpaired individuals. Our current understanding of the neurobiological mechanisms underpinning these alterations is limited but may be enhanced through the use of animal models of CI, which also exhibit alterations in nociceptive responding. Further research using additional behavioural indices of pain is warranted. Increased understanding of altered experimental pain processing in CI will facilitate the development of improved diagnostic and therapeutic approaches for pain in individuals with CI.

  7. Group-based multimodal exercises integrated with cognitive-behavioural therapy improve disability, pain and quality of life of subjects with chronic neck pain: a randomized controlled trial with one-year follow-up.

    PubMed

    Monticone, Marco; Ambrosini, Emilia; Rocca, Barbara; Cazzaniga, Daniele; Liquori, Valentina; Pedrocchi, Alessandra; Vernon, Howard

    2017-06-01

    To evaluate the effect of a group-based multidisciplinary rehabilitation programme on disability, pain and quality of life in subjects with chronic neck pain. Randomized controlled trial. Specialized rehabilitation centre. A total of 170 patients (mean age of 53 years (13); 121 females). The multidisciplinary group underwent a multidisciplinary rehabilitation programme combining multimodal exercises with psychologist-lead cognitive-behavioural therapy sessions. The general exercise group underwent general physiotherapy. Both groups followed group-based programmes once a week for ten weeks. Additionally, the multidisciplinary group met with the psychologist once a week for a 60-minute session. The Neck Disability Index (primary outcome), the Tampa Scale for Kinesiophobia, the Pain Catastrophizing Scale, a pain numerical rating scale and the Short-Form Health Survey. The participants were evaluated before, after training and after 12 months. A linear mixed model for repeated measures was used for each outcome measure. Significant effects ( p-value <0.001) were found over time and between groups for all outcome measures. After training, significant improvements were found for both groups for all outcome measures except kinesiophobia and catastrophizing, which did not change in the control group; however, the improvements were significantly greater for the multidisciplinary group. At 12-month follow-up a clinically meaningful between-group difference of 12.4 Neck Disability Index points was found for disability. A group-based multidisciplinary rehabilitation programme including cognitive-behavioural therapy was superior to group-based general physiotherapy in improving disability, pain and quality of life of subjects with chronic neck pain. The effects lasted for at least one year.

  8. Sex differences in pain: a brief review of clinical and experimental findings

    PubMed Central

    Bartley, E. J.; Fillingim, R. B.

    2013-01-01

    Summary Recent years have witnessed substantially increased research regarding sex differences in pain. The expansive body of literature in this area clearly suggests that men and women differ in their responses to pain, with increased pain sensitivity and risk for clinical pain commonly being observed among women. Also, differences in responsivity to pharmacological and non-pharmacological pain interventions have been observed; however, these effects are not always consistent and appear dependent on treatment type and characteristics of both the pain and the provider. Although the specific aetiological basis underlying these sex differences is unknown, it seems inevitable that multiple biological and psychosocial processes are contributing factors. For instance, emerging evidence suggests that genotype and endogenous opioid functioning play a causal role in these disparities, and considerable literature implicates sex hormones as factors influencing pain sensitivity. However, the specific modulatory effect of sex hormones on pain among men and women requires further exploration. Psychosocial processes such as pain coping and early-life exposure to stress may also explain sex differences in pain, in addition to stereotypical gender roles that may contribute to differences in pain expression. Therefore, this review will provide a brief overview of the extant literature examining sex-related differences in clinical and experimental pain, and highlights several biopsychosocial mechanisms implicated in these male–female differences. The future directions of this field of research are discussed with an emphasis aimed towards further elucidation of mechanisms which may inform future efforts to develop sex-specific treatments. PMID:23794645

  9. Patient-controlled epidural analgesia or multimodal pain regimen with periarticular injection after total hip arthroplasty: a randomized, double-blind, placebo-controlled study.

    PubMed

    Jules-Elysee, Kethy M; Goon, Amanda K; Westrich, Geoffrey H; Padgett, Douglas E; Mayman, David J; Ranawat, Amar S; Ranawat, Chitranjan S; Lin, Yi; Kahn, Richard L; Bhagat, Devan D; Goytizolo, Enrique A; Ma, Yan; Reid, Shane C; Curren, Jodie; YaDeau, Jacques T

    2015-05-20

    The optimal postoperative analgesia after primary total hip arthroplasty remains in question. This randomized, double-blind, placebo-controlled study compared the use of patient-controlled epidural analgesia (PCEA) with use of a multimodal pain regimen including periarticular injection (PAI). We hypothesized that PAI would lead to earlier readiness for discharge, decreased opioid consumption, and lower pain scores. Forty-one patients received PAI, and forty-three patients received PCEA. Preoperatively, both groups were administered dexamethasone (6 mg, orally). The PAI group received a clonidine patch and sustained-release oxycodone (10 mg), while the PCEA group had placebo. Both groups received combined spinal-epidural anesthesia and used an epidural pain pump postoperatively; the PAI group had normal saline solution, while the PCEA group had bupivacaine and hydromorphone. The primary outcome, readiness for discharge, required the discontinuation of the epidural, a pain score of <4 (numeric rating scale) without parenteral narcotics, normal eating, minimal nausea, urination without a catheter, a dry surgical wound, no acute medical problems, and the ability to independently transfer and walk 12.2 m (40 ft). The mean time to readiness for discharge (and standard deviation) was 2.4 ± 0.7 days (PAI) compared with 2.3 ± 0.8 days (PCEA) (p = 0.86). The mean length of stay was 3.0 ± 0.8 days (PAI) compared with 3.1 ± 0.7 days (PCEA) (p = 0.46). A significant mean difference in pain score of 0.74 with ambulation (p = 0.01; 95% confidence interval [CI], 0.18 to 1.31) and 0.80 during physical therapy (p = 0.03; 95% CI, 0.09 to 1.51) favored the PCEA group. The mean opioid consumption (oral morphine equivalents in milligrams) was significantly higher in the PAI group on postoperative day 0 (43 ± 21 compared with 28 ± 23; p = 0.002) and postoperative days 0 through 2 (136 ± 59 compared with 90 ± 79; p = 0.004). Opioid-Related Symptom Distress Scale (ORSDS) composite

  10. Asians differ from non-Hispanic Whites in experimental pain sensitivity.

    PubMed

    Rowell, Lauren N; Mechlin, Beth; Ji, Ellen; Addamo, Michael; Girdler, Susan S

    2011-08-01

    This study examined differences between Asians and non-Hispanic Whites (Whites) in pain sensitivity, and its relationship to mean arterial pressure (MAP) and heart rate (HR). In 30 Whites (50% female) and 30 Asians (50% female), experimental pain sensitivity was assessed with a hand cold pressor task, yielding measures of pain threshold, tolerance, intensity, and unpleasantness. Mean arterial pressure and HR measurements taken at rest and in response to speech stress were assessed. Perceived stress, anxiety, perfectionism, parental criticism, parental expectations and depressive symptoms were also measured. The results indicated that for the cold pain test, Asians demonstrated significantly lower pain threshold and tolerance levels than Whites. Although no ethnic differences were seen for MAP or HR responses to stress, for Whites higher stress MAP levels were correlated with reduced pain sensitivity, while for Asians higher baseline and stress HR levels were correlated with reduced pain sensitivity. Asians reported higher parental expectations and greater parental criticism than Whites. For Asians only, higher levels of perfectionism were related to more depressive symptoms, anxiety and perceived stress. These results indicate that Asian Americans are more sensitive to experimental pain than Whites and suggest ethnic differences in endogenous pain regulatory mechanisms (e.g. MAP and HR). The results may also have implications for understanding ethnic differences in clinical pain.

  11. Spinal Disinhibition in Experimental and Clinical Painful Diabetic Neuropathy.

    PubMed

    Marshall, Andrew G; Lee-Kubli, Corinne; Azmi, Shazli; Zhang, Michael; Ferdousi, Maryam; Mixcoatl-Zecuatl, Teresa; Petropoulos, Ioannis N; Ponirakis, Georgios; Fineman, Mark S; Fadavi, Hassan; Frizzi, Katie; Tavakoli, Mitra; Jeziorska, Maria; Jolivalt, Corinne G; Boulton, Andrew J M; Efron, Nathan; Calcutt, Nigel A; Malik, Rayaz A

    2017-02-15

    Impaired rate dependent depression (RDD) of the Hoffman-reflex is associated with reduced dorsal spinal cord potassium chloride co-transporter expression and impaired spinal GABAA receptor function, indicative of spinal inhibitory dysfunction. We have investigated the pathogenesis of impaired RDD in diabetic rodents exhibiting features of painful neuropathy and the translational potential of this marker of spinal inhibitory dysfunction in human painful diabetic neuropathy. Impaired RDD and allodynia were present in type 1 and type 2 diabetic rats but not in rats with type 1 diabetes receiving insulin supplementation that did not restore normoglycemia. Impaired RDD in diabetic rats was rapidly normalized by spinal delivery of duloxetine acting via 5HT2A receptors and temporally coincident with the alleviation of allodynia. Deficits in RDD and corneal nerve density were demonstrated in patients with painful diabetic neuropathy when compared to healthy control subjects and patients with painless diabetic neuropathy. Spinal inhibitory dysfunction and peripheral small fibre pathology may contribute to the clinical phenotype in painful diabetic neuropathy. Deficits in RDD may help to identify patients with spinally mediated painful diabetic neuropathy who may respond optimally to therapies such as duloxetine.

  12. Positive medium-term influence of multimodal pain management on socioeconomic factors and health care utilization in patients with lumbar radiculopathy: a prospective study

    PubMed Central

    Benditz, Achim; Loher, Martin; Boluki, Daniel; Grifka, Joachim; Völlner, Florian; Renkawitz, Tobias; Maderbacher, Günther; Götz, Jürgen

    2017-01-01

    Background Multimodal pain management (MPM) represents a central approach to avoiding surgery in patients with lumbar radiculopathy. Independent of the type of health system, cost effectiveness and socioeconomic factors are becoming increasingly important. This study investigated the medium-term influence of conservative MPM on health care utilization and socioeconomic factors. Methods This study compared subjective, objective, and socioeconomic factors of 60 patients after inpatient MPM because of lumbar radiculopathy, before and 1 year ± 2 weeks after treatment. Results Over the course of the 1-year follow-up, one-third of the patients had not required any conservative treatment in comparison to 100% of patients before MPM therapy. The number of patients requiring analgesics could be significantly reduced from 26 to 12, and the number of patients who did not require any analgesics had increased from 14 to 32. After 1 year, the number of patients who had to regularly contact a physician because of low back pain (once per month for 6 months) had been reduced from 58 to 27. Conclusion MPM is an effective approach to treating lumbar radiculopathy and reducing its negative influence on socioeconomic factors. Therapeutic benefits also include a decrease in health care utilization. Therefore, health care providers should place the mid-term success for patients and socioeconomic factors before the short-term costs of therapy. PMID:28243143

  13. Experimental verification of a novel MEMS multi-modal vibration energy harvester for ultra-low power remote sensing nodes

    NASA Astrophysics Data System (ADS)

    Iannacci, J.; Sordo, G.; Serra, E.; Kucera, M.; Schmid, U.

    2015-05-01

    In this work, we discuss the verification and preliminary experimental characterization of a MEMS-based vibration Energy Harvester (EH) design. The device, named Four-Leaf Clover (FLC), is based on a circular-shaped mechanical resonator with four petal-like mass-spring cascaded systems. This solution introduces several mechanical Degrees of Freedom (DOFs), and therefore enables multiple resonant modes and deformation shapes in the vibrations frequency range of interest. The target is to realize a wideband multi-modal EH-MEMS device, that overcomes the typical narrowband working characteristics of standard cantilevered EHs, by ensuring flexible and adaptable power source to ultra-low power electronics for integrated remote sensing nodes (e.g. Wireless Sensor Networks - WSNs) in the Internet of Things (IoT) scenario, aiming to self-powered and energy autonomous smart systems. Finite Element Method simulations of the FLC EH-MEMS show the presence of several resonant modes for vibrations up to 4-5 kHz, and level of converted power up to a few μW at resonance and in closed-loop conditions (i.e. with resistive load). On the other hand, the first experimental tests of FLC fabricated samples, conducted with a Laser Doppler Vibrometer (LDV), proved the presence of several resonant modes, and allowed to validate the accuracy of the FEM modeling method. Such a good accordance holds validity for what concerns the coupled field behavior of the FLC EH-MEMS, as well. Both measurements and simulations performed at 190 Hz (i.e. out of resonance) showed the generation of power in the range of nW (Root Mean Square - RMS values). Further steps of this work will include the experimental characterization in a full range of vibrations, aiming to prove the whole functionality of the FLC EH-MEMS proposed design concept.

  14. Analgesic efficacy of lidocaine and multimodal analgesia for chest tube removal: A randomized trial study1

    PubMed Central

    Pinheiro, Valdecy Ferreira de Oliveira; da Costa, José Madson Vidal; Cascudo, Marcelo Matos; Pinheiro, Ênio de Oliveira; Fernandes, Maria Angela Ferreira; de Araujo, Ivonete Batista

    2015-01-01

    Objective: to assess the analgesic efficacy of subcutaneous lidocaine and multimodal analgesia for chest tube removal following heart surgery. Methods: sixty volunteers were randomly allocated in two groups; 30 participants in the experimental group were given 1% subcutaneous lidocaine, and 30 controls were given a multimodal analgesia regime comprising systemic anti-inflammatory agents and opioids. The intensity and quality of pain and trait and state anxiety were assessed. The association between independent variables and final outcome was assessed by means of the Chi-squared test with Yates' correction and Fisher's exact test. Results: the groups did not exhibit significant difference with respect to the intensity of pain upon chest tube removal (p= 0.47). The most frequent descriptors of pain reported by the participants were pressing, sharp, pricking, burning and unbearable. Conclusion: the present study suggests that the analgesic effect of the subcutaneous administration of 1% lidocaine combined with multimodal analgesia is most efficacious. PMID:26625989

  15. Is experimentally induced pain associated with socioeconomic status? Do poor people hurt more?

    PubMed Central

    Miljković, Ana; Stipčić, Ana; Braš, Marijana; Đorđević, Veljko; Brajković, Lovorka; Hayward, Caroline; Pavić, Arsen; Kolčić, Ivana; Polašek, Ozren

    2014-01-01

    Background The association of pain and socioeconomic status is widely reported, yet much less clearly understood. The aim of this study was to investigate the association of experimentally induced pain threshold and tolerance with socioeconomic status. Material/Methods The study sample consisted of 319 adult subjects from the population of the island of Vis, Croatia, which was previously shown to have a high level of social homogeneity. A manual dolorimeter was used to measure mechanical pressure pain threshold (least stimulus intensity) and pain tolerance (maximum tolerance stimulus intensity) on both hands. Pain tolerance interval was defined as the difference between pain tolerance and threshold. Years of schooling and material status were used as socioeconomic estimates. Results Both of the socioeconomic estimates were significantly correlated with pain threshold, tolerance, and tolerance interval (P<0.001). The mixed modeling analysis, controlled for the effects of age, gender, and 4 psychological variables, indicated that education was not a significant predictor in any of the 3 models. However, lower material status was significantly associated with lower pain tolerance (P=0.038) and narrower pain tolerance interval (P=0.032), but not with pain threshold (P=0.506). The overall percentages of explained variance were lower in the tolerance interval model (20.2%) than in pain tolerance (23.1%) and threshold (33.1%), suggesting the increasing share of other confounding variables in pain tolerance and even more so in tolerance interval model. Conclusions These results suggest a significant association between experimentally induced pain tolerance and tolerance interval with material status, suggesting that poor people indeed do hurt more. PMID:25029965

  16. Experimental tonic hand pain modulates the corticospinal plasticity induced by a subsequent hand deafferentation.

    PubMed

    Mavromatis, N; Gagné, M; Voisin, J I A V; Reilly, K T; Mercier, C

    2016-08-25

    Sensorimotor reorganization is believed to play an important role in the development and maintenance of phantom limb pain, but pain itself might modulate sensorimotor plasticity induced by deafferentation. Clinical and basic research support this idea, as pain prior to amputation increases the risk of developing post-amputation pain. The aim of this study was to examine the influence of experimental tonic cutaneous hand pain on the plasticity induced by temporary ischemic hand deafferentation. Sixteen healthy subjects participated in two experimental sessions (Pain, No Pain) in which transcranial magnetic stimulation was used to assess corticospinal excitability in two forearm muscles (flexor carpi radialis and flexor digitorum superficialis) before (T0, T10, T20, and T40) and after (T60 and T75) inflation of a cuff around the wrist. The cuff was inflated at T45 in both sessions and in the Pain session capsaicin cream was applied on the dorsum of the hand at T5. Corticospinal excitability was significantly greater during the Post-inflation phase (p=0.002) and increased similarly in both muscles (p=0.861). Importantly, the excitability increase in the Post-inflation phase was greater for the Pain than the No-Pain condition (p=0.006). Post-hoc analyses revealed a significant difference between the two conditions during the Post-inflation phase (p=0.030) but no difference during the Pre-inflation phase (p=0.601). In other words, the corticospinal facilitation was greater when pain was present prior to cuff inflation. These results indicate that pain can modulate the plasticity induced by another event, and could partially explain the sensorimotor reorganization often reported in chronic pain populations. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Antinociceptive Interaction of Tramadol with Gabapentin in Experimental Mononeuropathic Pain.

    PubMed

    Miranda, Hugo F; Noriega, Viviana; Prieto, Juan Carlos; Zanetta, Pilar; Castillo, Rodrigo; Aranda, Nicolás; Sierralta, Fernando

    2016-08-01

    Neuropathic pain is the result of injury to the nervous system, and different animal models have been established to meet the manifestations of neuropathy. The pharmacotherapy for neuropathic pain includes gabapentin and tramadol, but these are only partially effective when given alone. The aim of this study was to assess the antinociceptive interaction between both drugs using the isobolographic analysis and changes of the IL-1β concentration in a mouse model of neuropathic pain (partial sciatic nerve ligation or PSNL). The i.p. administration of gabapentin (5-100 mg/kg) or tramadol (12.5-100 mg/kg) displayed a dose-dependent antinociception in the hot plate assay of PSNL mice, and effects induced by gabapentin with tramadol were synergistic. Administration of gabapentin or tramadol reversed significantly the increase in the concentration of IL-1β induced by PSNL after either 7 or 14 days and their combination was significantly more potent in reversing the elevated concentration of IL-1β. The synergism obtained by the co-administration of gabapentin and tramadol is proposed to result from action on different mechanisms in pain pathways. Gabapentin or tramadol or their combination modulates the expression of pro-inflammatory cytokine, IL-1β, in a model of mice PSNL which could be due to an inhibition of glial function. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

  18. Side effects of pain and analgesia in animal experimentation.

    PubMed

    Jirkof, Paulin

    2017-03-22

    This review highlights selected effects of untreated pain and of widely used analgesics such as opioids, non-steroid anti-inflammatory drugs and antipyretics, to illustrate the relevance of carefully planned, appropriate and controlled analgesia for greater reproducibility in animal experiments involving laboratory rodents.

  19. Tryptase - PAR2 axis in Experimental Autoimmune Prostatitis, a model for Chronic Pelvic Pain Syndrome

    PubMed Central

    Roman, Kenny; Done, Joseph D.; Schaeffer, Anthony J.; Murphy, Stephen F.; Thumbikat, Praveen

    2014-01-01

    Chronic prostatitis/Chronic pelvic pain syndrome (CP/CPPS) affects up to 15% of the male population and is characterized by pelvic pain. Mast cells are implicated in the murine experimental autoimmune prostatitis (EAP) model as key to chronic pelvic pain development. The mast cell mediator tryptase-β and its cognate receptor protease-activated receptor 2 (PAR2) are involved in mediating pain in other visceral disease models. Prostatic secretions and urines from CP/CPPS patients were examined for the presence of mast cell degranulation products. Tryptase-β and PAR2 expression were examined in murine experimental autoimmune prostatitis (EAP). Pelvic pain and inflammation were assessed in the presence or absence of PAR2 expression and upon PAR2 neutralization. Tryptase-β and carboxypeptidase A3 were elevated in CP/CPPS compared to healthy volunteers. Tryptase-β was capable of inducing pelvic pain and was increased in EAP along with its receptor PAR2. PAR2 was required for the development of chronic pelvic pain in EAP. PAR2 signaling in dorsal root ganglia lead to ERK1/2 phosphorylation and calcium influx. PAR2 neutralization using antibodies attenuated chronic pelvic pain in EAP. The tryptase-PAR2 axis is an important mediator of pelvic pain in EAP and may play a role in the pathogenesis of CP/CPPS. PMID:24726923

  20. Is distraction less effective when pain is threatening? An experimental investigation with the cold pressor task.

    PubMed

    Van Damme, Stefaan; Crombez, Geert; Van Nieuwenborgh-De Wever, Kathleen; Goubert, Liesbet

    2008-01-01

    Distraction is a commonly used strategy to control pain. However there is doubt about its effectiveness as a clinical tool, and results from both experimental and clinical studies remain inconclusive. Recent theoretical advancements suggest that distraction of attention may be less effective when pain is threatening. The aim of the present study was to experimentally investigate this hypothesis. Pain-free volunteers (N=101) participated in a cold pressor test. Half of the participants simultaneously performed a cognitive distraction task, the other half did not. The threat value of the pain was manipulated by means of verbal information. The results showed that distraction resulted in less attention to the pain and lower pain ratings once the cold pressor procedure was halted. The hypothesis that the effectiveness of distraction is modulated by the threat value of pain could not be confirmed. However, threatening information increased catastrophic thoughts and anxiety, and interfered with performance on the distraction task. These findings suggest that caution is required in using distraction as a pain control strategy when the threat value is high, because fearful appraisal of pain is associated with less engagement in distraction tasks.

  1. The effects of experimental pain and induced optimism on working memory task performance.

    PubMed

    Boselie, Jantine J L M; Vancleef, Linda M G; Peters, Madelon L

    2016-07-01

    Pain can interrupt and deteriorate executive task performance. We have previously shown that experimentally induced optimism can diminish the deteriorating effect of cold pressor pain on a subsequent working memory task (i.e., operation span task). In two successive experiments we sought further evidence for the protective role of optimism on pain-induced working memory impairments. We used another working memory task (i.e., 2-back task) that was performed either after or during pain induction. Study 1 employed a 2 (optimism vs. no-optimism)×2 (pain vs. no-pain)×2 (pre-score vs. post-score) mixed factorial design. In half of the participants optimism was induced by the Best Possible Self (BPS) manipulation, which required them to write and visualize about a life in the future where everything turned out for the best. In the control condition, participants wrote and visualized a typical day in their life (TD). Next, participants completed either the cold pressor task (CPT) or a warm water control task (WWCT). Before (baseline) and after the CPT or WWCT participants working memory performance was measured with the 2-back task. The 2-back task measures the ability to monitor and update working memory representation by asking participants to indicate whether the current stimulus corresponds to the stimulus that was presented 2 stimuli ago. Study 2 had a 2 (optimism vs. no-optimism)×2 (pain vs. no-pain) mixed factorial design. After receiving the BPS or control manipulation, participants completed the 2-back task twice: once with painful heat stimulation, and once without any stimulation (counter-balanced order). Continuous heat stimulation was used with temperatures oscillating around 1°C above and 1°C below the individual pain threshold. In study 1, the results did not show an effect of cold pressor pain on subsequent 2-back task performance. Results of study 2 indicated that heat pain impaired concurrent 2-back task performance. However, no evidence was found

  2. Effect of adding intrathecal morphine to a multimodal analgesic regimen for postoperative pain management after laparoscopic bariatric surgery: a prospective, double-blind, randomized controlled trial

    PubMed Central

    El Sherif, Fatma Adel; Othman, Ahmed Hassan; Abd El-Rahman, Ahmad Mohammad; Taha, Osama

    2016-01-01

    Background: Pain control after bariatric surgery is a major challenge. Our objective was to study the efficacy and safety of intrathecal (IT) morphine 0.3 mg added to bupivacaine 0.5% for postoperative pain after laparoscopic bariatric surgery. Methods: After local ethics committee approval, 100 morbidly obese patients scheduled for laparoscopic bariatric surgery were enrolled in this study. Patients were randomly assigned into two groups: Group I received IT 0.3 mg morphine (0.3 mL) added to 1.2 mL of bupivacaine 0.5%; Group II received IT 0.3 mL saline added to 1.2 mL of bupivacaine 0.5%, immediately before induction of general anaesthesia. For both groups, 60 mg ketorolac and 1000 mg paracetamol were infused 30 minutes before the end of surgery. After wound closure, 20 mL bupivacaine 0.25% was infiltrated at wound edges. Results: Visual Analogue Scale (VAS) score was significantly lower in group I immediately, 30 minutes and 1 hour postoperatively. Time to first ambulation, return of intestinal sounds and hospital stay were shorter in group I than group II (p < 0.05); total morphine consumption was significantly lower in group I than group II (p < 0.05). Sedation score was significantly higher in group I immediately postoperatively, while at 30 minutes, 1, 2 and 6 hours postoperatively sedation scores were significantly higher in group II. Itching was significantly higher in group I. Conclusion: The addition of IT morphine to a multimodal analgesic regimen after laparoscopic bariatric surgery was an effective and safe method that markedly reduced postoperative pain, systemic opioid consumption and length of hospital stay. PMID:27867510

  3. Experimenter Effects on Pain Reporting in Women Vary across the Menstrual Cycle

    PubMed Central

    Vigil, Jacob M.; DiDomenico, Jared; Strenth, Chance; Coulombe, Patrick; Kruger, Eric; Mueller, Andrea A.; Guevara Beltran, Diego; Adams, Ian

    2015-01-01

    Background. Separate lines of research have shown that menstrual cycling and contextual factors such as the gender of research personnel influence experimental pain reporting. Objectives. This study examines how brief, procedural interactions with female and male experimenters can affect experimentally reported pain (cold pressor task, CPT) across the menstrual cycle. Methods. Based on the menstrual calendars 94 naturally cycling women and 38 women using hormonal contraceptives (Mage = 19.83,  SD = 3.09) were assigned to low and high fertility groups. This assignment was based on estimates of their probability of conception given their current cycle day. Experimenters (12 males, 7 females) engaged in minimal procedural interactions with participants before the CPT was performed in solitude. Results. Naturally cycling women in the high fertility group showed significantly higher pain tolerance (81 sec, d = .79) following interactions with a male but not a female experimenter. Differences were not found for women in the low fertility or contraceptive groups. Discussion. The findings illustrate that menstrual functioning moderates the effect that experimenter gender has on pain reporting in women. Conclusion. These findings have implications for standardizing pain measurement protocols and understanding how basic biopsychosocial mechanisms (e.g., person-perception systems) can modulate pain experiences. PMID:25892990

  4. Implementation of WHO multimodal strategy for improvement of hand hygiene: a quasi-experimental study in a Traditional Chinese Medicine hospital in Xi'an, China.

    PubMed

    Shen, Li; Wang, Xiaoqing; An, Junming; An, Jialu; Zhou, Ning; Sun, Lu; Chen, Hong; Feng, Lin; Han, Jing; Liu, Xiaorong

    2017-01-01

    Hand hygiene (HH) is an essential component for preventing and controlling of healthcare-associated infection (HAI), whereas compliance with HH among health care workers (HCWs) is frequently poor. This study aimed to assess compliance and correctness with HH before and after the implementation of a multimodal HH improvement strategy launched by the World Health Organization (WHO). A quasi-experimental study design including questionnaire survey generalizing possible factors affecting HH behaviors of HCWs and direct observation method was used to evaluate the effectiveness of WHO multimodal HH strategy in a hospital of Traditional Chinese Medicine. Multimodal HH improvement strategy was drawn up according to the results of questionnaire survey. Compliance and correctness with HH among HCWs were compared before and after intervention. Also HH practices for different indications based on WHO "My Five Moments for Hand Hygiene" were recorded. In total, 553 HCWs participated in the questionnaire survey and multimodal HH improvement strategy was developed based on individual, environment and management levels. A total of 5044 observations in 23 wards were recorded in this investigation. The rate of compliance and correctness with HH improved from 66.27% and 47.75% at baseline to 80.53% and 88.35% after intervention. Doctors seemed to have better compliance with HH after intervention (84.04%) than nurses and other HCWs (81.07% and 69.42%, respectively). When stratified by indication, compliance with HH improved for all indications after intervention (P < 0.05) except for "after body fluid exposure risk" and "after touching patient surroundings". Implementing the WHO multimodal HH strategy can significantly improve HH compliance and correctness among HCWs.

  5. Placebo effect of an inert gel on experimentally induced leg muscle pain

    PubMed Central

    Hopker, James G; Foad, Abigail J; Beedie, Christopher J; Coleman, Damian A; Leach, Geoffrey

    2010-01-01

    Purpose This study examined the therapeutic effects of an inert placebo gel on experimentally induced muscle pain in a sports therapy setting. It aimed to investigate the degree to which conditioned analgesia, coupled with an expectation of intervention, was a factor in subsequent analgesia. Methods Participants were sixteen male and eight female sports therapy students at a UK University. With institutional ethics board approval and following informed consent procedures, each was exposed to pain stimulus in the lower leg in five conditions, ie, conditioning, prebaseline, experimental (two placebo gel applications), and postbaseline. In conditioning trials, participants identified a level of pain stimulus equivalent to a perceived pain rating of 6/10. An inert placebo gel was then applied to the site with the explicit instruction that it was an analgesic. Participants were re-exposed to the pain stimulus, the level of which, without their knowledge, had been decreased, creating the impression of an analgesic effect resulting from the gel. In experimental conditions, the placebo gel was applied and the level of pain stimulus required to elicit a pain rating of 6/10 recorded. Results Following application of the placebo gel, the level of pain stimulus required to elicit a pain rating of 6/10 increased by 8.2%. Application of the placebo gel significantly decreased participant’s perceptions of muscle pain (P = 0.001). Conclusion Subjects’ experience and expectation of pain reduction may be major factors in the therapeutic process. These factors should be considered in the sports therapeutic environment. PMID:24198560

  6. Virtual reality immersion method of distraction to control experimental ischemic pain.

    PubMed

    Magora, Florella; Cohen, Sarale; Shochina, Mara; Dayan, Ehud

    2006-04-01

    Virtual reality immersion has been advocated as a new effective adjunct to drugs for pain control. The attenuation of pain perception and unpleasantness has been attributed to the patient's attention being diverted from the real, external environment through immersion in a virtual environment transmitted by an interactive 3-D software computer program via a VR helmet. To investigate whether VR immersion can extend the amount of time subjects can tolerate ischemic tourniquet pain. The study group comprised 20 healthy adult volunteers. The pain was induced by an inflated blood pressure cuff during two separate, counterbalanced, randomized experimental conditions for each subject: one with VR and the control without VR exposure. The VR equipment consisted of a standard computer, a lightweight helmet and an interactive software game. Tolerance time to ischemia was significantly longer for VR conditions than for those without (P < 0.001). Visual Analogue Scale (0-10) ratings were recorded for pain intensity, pain unpleasantness, and the time spent thinking about pain. Affective distress ratings of unpleasantness and of time spent thinking about pain were significantly lower during VR as compared with the control condition (P< 0.003 and 0.001 respectively). The VR method in pain control was shown to be beneficial. The relatively inexpensive equipment will facilitate the use of VR immersion in clinical situations. Future research is necessary to establish the optimal selection of clinical patients appropriate for VR pain therapy and the type of software required according to age, gender, personality, and cultural factors.

  7. Clinical pharmacology of analgesics assessed with human experimental pain models: bridging basic and clinical research

    PubMed Central

    Oertel, Bruno Georg; Lötsch, Jörn

    2013-01-01

    The medical impact of pain is such that much effort is being applied to develop novel analgesic drugs directed towards new targets and to investigate the analgesic efficacy of known drugs. Ongoing research requires cost-saving tools to translate basic science knowledge into clinically effective analgesic compounds. In this review we have re-examined the prediction of clinical analgesia by human experimental pain models as a basis for model selection in phase I studies. The overall prediction of analgesic efficacy or failure of a drug correlated well between experimental and clinical settings. However, correct model selection requires more detailed information about which model predicts a particular clinical pain condition. We hypothesized that if an analgesic drug was effective in an experimental pain model and also a specific clinical pain condition, then that model might be predictive for that particular condition and should be selected for development as an analgesic for that condition. The validity of the prediction increases with an increase in the numbers of analgesic drug classes for which this agreement was shown. From available evidence, only five clinical pain conditions were correctly predicted by seven different pain models for at least three different drugs. Most of these models combine a sensitization method. The analysis also identified several models with low impact with respect to their clinical translation. Thus, the presently identified agreements and non-agreements between analgesic effects on experimental and on clinical pain may serve as a solid basis to identify complex sets of human pain models that bridge basic science with clinical pain research. PMID:23082949

  8. Peripheral opioid analgesia in experimental human pain models.

    PubMed

    Tegeder, Irmgard; Meier, Silke; Burian, Maria; Schmidt, Helmut; Geisslinger, Gerd; Lötsch, Jörn

    2003-05-01

    This placebo-controlled, double-blind crossover study assessed whether exclusive activation of peripheral opioid receptors results in significant pain reduction. To achieve opioid activity restricted to the periphery, we used a short-term (2 h) low dose infusion of morphine-6-beta-glucuronide (M6G) because M6G does not pass the blood-brain barrier during this time in amounts sufficient to induce CNS effects. The lack of central opioid effects of M6G was confirmed by a lack of change of the pupil size and absence of other opioid-related CNS effects. As a positive control, morphine was infused at a dosage that definitely produced CNS effects. This was evident by a rapid decrease of the pupil size and by other typical opioid-related side effects including nausea, vomiting, itchiness, hiccup and sedation. Three different pain models were employed to evaluate the analgesic effects: (i) cutaneous inflammatory hyperalgesia induced by briefly freezing a small skin area to -30 degrees C ('freeze lesion'); (ii) muscle hyperalgesia induced by a series of concentric and eccentric muscle contractions (DOMS model; delayed onset of muscle soreness); and (iii) pain induced by electrical current (5 Hz sinus stimuli of 0-10 mA). M6G significantly reduced cutaneous hyperalgesia in the 'freeze lesion' model as assessed with von Frey hairs. It also reduced muscle hyperalgesia in the DOMS model. Electrical pain, however, was not affected by M6G. Morphine was significantly more active in the 'freeze lesion' and DOMS model, and also significantly increased the electrical pain threshold and tolerance. Subcutaneous tissue concentrations of M6G and morphine as assessed with microdialysis were about half those of the respective plasma concentrations. The results of the study indicate that M6G has antihyperalgesic effects in inflammatory pain through activation of peripheral opioid receptors. Since this occurs at concentrations that do not cause central opioid effects, M6G might be useful as a

  9. It’s About Me: Patients’ Experiences of Patient Participation in the Web Behavior Change Program for Activity in Combination With Multimodal Pain Rehabilitation

    PubMed Central

    Michaelson, Peter; Eriksson, Margareta K; Gard, Gunvor

    2017-01-01

    Background Patients’ participation in their health care is recognized as a key component in high-quality health care. Persons with persistent pain are recommended treatments with a cognitive approach from a biopsychosocial explanation of pain, in which a patient’s active participation in their rehabilitation is in focus. Web-based interventions for pain management have the potential to increase patient participation by enabling persons to play a more active role in rehabilitation. However, little is known about patients’ experiences of patient participation in Web-based interventions in clinical practice. Objective The objective of our study was to explore patients’ experiences of patient participation in a Web Behavior Change Program for Activity (Web-BCPA) in combination with multimodal rehabilitation (MMR) among patients with persistent pain in primary health care. Methods Qualitative interviews were conducted with 15 women and 4 men, with a mean age of 45 years. Data were analyzed with qualitative content analysis. Results One theme, “It’s about me,” and 4 categories, “Take part in a flexible framework of own priority,” “Acquire knowledge and insights,” “Ways toward change,” and “Personal and environmental conditions influencing participation,” were developed. Patient participation was depicted as being confirmed in an individualized and structured rehabilitation framework of one’s own choice. Being confirmed was fundamental to patient participation in the interaction with the Web-BCPA and with the health care professionals in MMR. To acquire knowledge and insights about pain and their life situation, through self-reflection in the solitary work in the Web-BCPA and through feedback from the health care professionals in MMR, was experienced as patient participation by the participants. Patient participation was described as structured ways to reach their goals of behavior change, which included analyzing resources and restrictions

  10. It's About Me: Patients' Experiences of Patient Participation in the Web Behavior Change Program for Activity in Combination With Multimodal Pain Rehabilitation.

    PubMed

    Nordin, Catharina; Michaelson, Peter; Eriksson, Margareta K; Gard, Gunvor

    2017-01-18

    Patients' participation in their health care is recognized as a key component in high-quality health care. Persons with persistent pain are recommended treatments with a cognitive approach from a biopsychosocial explanation of pain, in which a patient's active participation in their rehabilitation is in focus. Web-based interventions for pain management have the potential to increase patient participation by enabling persons to play a more active role in rehabilitation. However, little is known about patients' experiences of patient participation in Web-based interventions in clinical practice. The objective of our study was to explore patients' experiences of patient participation in a Web Behavior Change Program for Activity (Web-BCPA) in combination with multimodal rehabilitation (MMR) among patients with persistent pain in primary health care. Qualitative interviews were conducted with 15 women and 4 men, with a mean age of 45 years. Data were analyzed with qualitative content analysis. One theme, "It's about me," and 4 categories, "Take part in a flexible framework of own priority," "Acquire knowledge and insights," "Ways toward change," and "Personal and environmental conditions influencing participation," were developed. Patient participation was depicted as being confirmed in an individualized and structured rehabilitation framework of one's own choice. Being confirmed was fundamental to patient participation in the interaction with the Web-BCPA and with the health care professionals in MMR. To acquire knowledge and insights about pain and their life situation, through self-reflection in the solitary work in the Web-BCPA and through feedback from the health care professionals in MMR, was experienced as patient participation by the participants. Patient participation was described as structured ways to reach their goals of behavior change, which included analyzing resources and restrictions, problem solving, and evaluation. The individual's emotional and

  11. Pain: A Statistical Account

    PubMed Central

    Thacker, Michael A.; Moseley, G. Lorimer

    2017-01-01

    Perception is seen as a process that utilises partial and noisy information to construct a coherent understanding of the world. Here we argue that the experience of pain is no different; it is based on incomplete, multimodal information, which is used to estimate potential bodily threat. We outline a Bayesian inference model, incorporating the key components of cue combination, causal inference, and temporal integration, which highlights the statistical problems in everyday perception. It is from this platform that we are able to review the pain literature, providing evidence from experimental, acute, and persistent phenomena to demonstrate the advantages of adopting a statistical account in pain. Our probabilistic conceptualisation suggests a principles-based view of pain, explaining a broad range of experimental and clinical findings and making testable predictions. PMID:28081134

  12. Modulation of trigeminal laser evoked potentials and laser silent periods by homotopical experimental pain.

    PubMed

    Romaniello, Antonietta; Arendt-Nielsen, Lars; Cruccu, Giorgio; Svensson, Peter

    2002-07-01

    Cutaneous laser stimulation activates predominantly the A-delta and C mechano-heat nociceptors. Applied to the perioral region, low intensity CO(2)-laser pulses evoke reproducible trigeminal cortical evoked potentials (LEPs). High intensity CO(2)-laser stimuli induce a reflex response in the contracted jaw-closing muscle, the so-called laser silent period (LSP). Both LEPs and LSP provide a useful tool to study the physiology of the trigeminal nociceptive system. In ten healthy subjects we recorded the subjective ratings of the perioral laser stimulation and the trigeminal LEPs and LSP before, during and after homotopic experimental tonic muscle (infusion of hypertonic saline into the masseter muscle) and tonic skin pain (topical application of capsaicin to the cheek). LEPs were recorded from the vertex at two stimulus intensities: low (1.1 x pain threshold, PTh) and high (1.5 x PTh). LSP from masseter and temporalis muscles were recorded bilaterally through surface electromyographic (EMG) electrodes. CO(2)-laser pulses were applied to the perioral region (V2/V3) on the painful and non-painful side. The amplitude of LEPs increased with higher stimulus intensities (P<0.0001), but were suppressed by 42.3+/-5.3% during experimental muscle pain (P<0.0001) and by 41.6+/-3.2% during skin pain (P<0.0001). No pain-related effects were observed for the N and P latency of the LEPs (P> 0.20). The LSP in the masseter and temporalis muscles had similar onset-latency (80+/-5 ms), offset-latency (111+/-5 ms) and duration (31+/-4 ms). Experimental pain had no effect on the onset- and offset-latency (P>0.05). Experimental pain, whether from muscle or from skin, reduced the degree of suppression (P<0.01) and the area under the EMG curve (P< 0.005) of the LSP. The LSP was still suppressed during the post-pain recordings when the skin pain had disappeared (P<0.05). In all experiments experimental tonic pain decreased the subjective ratings of the perioral laser stimulation (P< 0

  13. Effects of restricted environmental stimulation: enhancement of hypnotizability for experimental and chronic pain control.

    PubMed

    Barabasz, A F; Barabasz, M

    1989-07-01

    Enhancement of hypnotizability and pain tolerance has been demonstrated using restricted environmental stimulation therapy (REST) with university students as Ss (A. F. Barabasz, 1982). The purpose of the present study was to determine whether or not similar results could be obtained with chronic pain patients. Ss consisted of outpatients in treatment for conditions in which pain is prominent who also demonstrated low hypnotizability after repeated hypnosis plateau sessions. 2 groups of Ss were exposed to REST. Situational demand characteristics (Orne, 1962) favored an increase in hypnotizability for REST Group 1 (high demand). REST Group 2 (low demand) was exposed to situational demand characteristics designed to disguise the experimental hypothesis. 2 groups of control Ss were exposed to the same alternative demand characteristic manipulations as the experimental groups, but environmental stimulation was maintained. The Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C) of Weitzenhoffer and E. R. Hilgard (1962), including a posthypnotic suggestion for an anesthetic reaction, and an ischemic pain test were administered prior to treatment and again immediately following treatment. After 6 hours of REST, significant increases in SHSS:C scores were found for high-demand and low-demand experimental Ss, as well as for high-demand control Ss. No such increase was found for low-demand controls. Significant decreases in pain scores were found for both high- and low-demand experimental groups. No significant pain score decreases were found for either control group, suggesting a relatively weak effect of demand characteristics. An independent postexperimental inquiry suggested all Ss believed they received active treatments. The inquiry, conducted 10-15 days after the experiment, also revealed a majority of experimental Ss were using hypnosis on a daily basis to reduce pain with a substantial decrease in pain medication. Only 2 control Ss (highest in hypnotizability

  14. Statins alleviate experimental nerve injury-induced neuropathic pain.

    PubMed

    Shi, Xiang Qun; Lim, Tony K Y; Lee, Seunghwan; Zhao, Yuan Qing; Zhang, Ji

    2011-05-01

    The statins are a well-established class of drugs that lower plasma cholesterol levels by inhibiting HMG-CoA (3-hydroxy-3-methyl-glutaryl-coenzyme A) reductase. They are widely used for the treatment of hypercholesterolemia and for the prevention of coronary heart disease. Recent studies suggest that statins have anti-inflammatory effects beyond their lipid-lowering properties. We sought to investigate whether statins could affect neuropathic pain by mediating nerve injury-associated inflammatory responses. The effects of hydrophilic rosuvastatin and lipophilic simvastatin were examined in the mouse partial sciatic nerve ligation model. Systemic daily administration of either statin from days 0 to 14 completely prevented the development of mechanical allodynia and thermal hyperalgesia. When administered from days 8 to 14 after injury, both statins dose-dependently reduced established hypersensitivity. After treatment, the effects of the statins were washed out within 2 to 7 days, depending on dose. Effects of both statins in alleviating mechanical allodynia were further confirmed in a different injury-associated neuropathic pain model, mental nerve chronic constriction, in rats. Both statins were able to abolish interleukin-1β expression in sciatic nerve triggered by nerve ligation. Additionally, quantitative analysis with Iba-1 and glial fibrillary acid protein immunoreactivity demonstrated that rosuvastatin and simvastatin significantly reduced the spinal microglial and astrocyte activation produced by sciatic nerve injury. The increase of interleukin-1β mRNA in the ipsilateral side of spinal cords was also reduced by the treatment of either statin. We identified a potential new application of statins in the treatment of neuropathic pain. The pain-alleviating effects of statins are likely attributable to their immunomodulatory effects.

  15. Multimodality Imaging of the Painful Elbow: Current Imaging Concepts and Image-Guided Treatments for the Injured Thrower's Elbow.

    PubMed

    Gustas, Cristy N; Lee, Kenneth S

    2016-09-01

    Elbow pain in overhead sport athletes is not uncommon. Repetitive throwing can lead to chronic overuse and/or acute injury to tendons, ligaments, bones, or nerves about the elbow. A thorough history and physical examination of the thrower's elbow frequently establishes the diagnosis for pain. Imaging can provide additional information when the clinical picture is unclear or further information is necessary for risk stratification and treatment planning. This article focuses on current imaging concepts and image-guided treatments for injuries commonly affecting the adult throwing athlete's elbow.

  16. Abnormal Pain Response to Visual Feedback During Cervical Movements in Chronic Whiplash: An Experimental Study.

    PubMed

    De Kooning, Margot; Daenen, Liesbeth; Verhelpen, Sam; Don, Sanneke; Voogt, Lennard; Roussel, Nathalie; Ickmans, Kelly; Van Loo, Michel; Cras, Patrick; Nijs, Jo

    2017-02-01

    Whiplash-associated disorders (WAD) are a debilitating condition. In chronic WAD, sensorimotor incongruence exacerbates symptoms. Sensorimotor incongruence occurs when somatosensory input and predicted motor output are in conflict, which can trigger pain. On the other hand, there is evidence that visual feedback can decrease pain in certain chronic pain conditions. Therefore, the aim of this study was to examine the effect of visual feedback and sensorimotor incongruence on pain thresholds in chronic WAD. Sixty-four participants (healthy controls and patients with chronic WAD) were subjected to six experimental conditions. Participants watched correct real-time or modified visual feedback of the neck or hand (without movement as well as during repetitive neck lateroflexion). Sensorimotor incongruence was induced by manipulating visual feedback. Pressure pain thresholds were measured at baseline and during each condition. Marked between-group differences were observed. Visual feedback of the neck-correct or modified-did not influence pain thresholds in chronic WAD. In contrast, healthy controls had significantly higher pain thresholds when provided with the correct or modified visual feedback. When a movement of the neck was added during visual feedback, patients with chronic WAD showed no significant difference in pain thresholds, while an increase in pain thresholds was found in the healthy control group. In contrast to the healthy controls, visual feedback and sensorimotor incongruence did not alter pain thresholds in patients with chronic WAD. These findings suggest an abnormal pain response to visual feedback and somatosensory incongruence as well as failing mechanisms of pain inhibition in chronic WAD. © 2016 World Institute of Pain.

  17. The role of periodontal ASIC3 in orofacial pain induced by experimental tooth movement in rats.

    PubMed

    Gao, Meiya; Long, Hu; Ma, Wenqiang; Liao, Lina; Yang, Xin; Zhou, Yang; Shan, Di; Huang, Renhuan; Jian, Fan; Wang, Yan; Lai, Wenli

    2016-12-01

    This study aimed to clarify the roles of Acid-sensing ion channel 3 (ASIC3) in orofacial pain following experimental tooth movement. Sixty male Sprague-Dawley rats were divided into the experimental group (40g, n = 30) and the sham group (0g, n = 30). Closed coil springs were ligated between maxillary incisor and molars to achieve experimental tooth movement. Rat grimace scale (RGS) scores were assessed at 0, 1, 3, 5, 7, and 14 days after the placement of the springs. ASIC3 immunostaining was performed and the expression levels of ASIC3 were measured through integrated optical density/area in Image-Pro Plus 6.0. Moreover, 18 rats were divided into APETx2 group (n = 6), amiloride group (n = 6), and vehicle group (n = 6), and RGS scores were obtained compared among them to verify the roles of ASIC3 in orofacial pain following tooth movement. ASIC3 expression levels became significantly higher in the experimental group than in sham group on 1, 3, and 5 days and became similar on 7 and 14 days. Pain levels (RGS scores) increased in both groups and were significantly higher in the experimental group on 1, 3, 5, and 7 days and were similar on 14 days. Periodontal ASIC3 expression levels were correlated with orofacial pain levels following experimental tooth movement. Periodontal administrations of ASIC3 antagonists (APETx2 and amiloride) could alleviate pain. This study needs to be better evidenced by RNA interference of ASIC3 in periodontal tissues in rats following experimental tooth movement. Moreover, we hope further studies would concentrate on the pain perception of ASIC3 knockout (ASIC3(-/-)) mice. Our results suggest that periodontal ASIC3 plays an important role in orofacial pain induced by experimental tooth movement. © The Author 2015. Published by Oxford University Press on behalf of the European Orthodontic Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  18. Sex Differences in How Social Networks and Relationship Quality Influence Experimental Pain Sensitivity

    PubMed Central

    Vigil, Jacob M.; Rowell, Lauren N.; Chouteau, Simone; Chavez, Alexandre; Jaramillo, Elisa; Neal, Michael; Waid, David

    2013-01-01

    This is the first study to examine how both structural and functional components of individuals’ social networks may moderate the association between biological sex and experimental pain sensitivity. One hundred and fifty-two healthy adults (mean age = 22yrs., 53% males) were measured for cold pressor task (CPT) pain sensitivity (i.e., intensity ratings) and core aspects of social networks (e.g., proportion of friends vs. family, affection, affirmation, and aid). Results showed consistent sex differences in how social network structures and intimate relationship functioning modulated pain sensitivity. Females showed higher pain sensitivity when their social networks consisted of a higher proportion of intimate types of relationship partners (e.g., kin vs. non kin), when they had known their network partners for a longer period of time, and when they reported higher levels of logistical support from their significant other (e.g., romantic partner). Conversely, males showed distinct patterns in the opposite direction, including an association between higher levels of logistical support from one’s significant other and lower CPT pain intensity. These findings show for the first time that the direction of sex differences in exogenous pain sensitivity is likely dependent on fundamental components of the individual’s social environment. The utility of a social-signaling perspective of pain behaviors for examining, comparing, and interpreting individual and group differences in experimental and clinical pain reports is discussed. PMID:24223836

  19. Sex differences in how social networks and relationship quality influence experimental pain sensitivity.

    PubMed

    Vigil, Jacob M; Rowell, Lauren N; Chouteau, Simone; Chavez, Alexandre; Jaramillo, Elisa; Neal, Michael; Waid, David

    2013-01-01

    This is the first study to examine how both structural and functional components of individuals' social networks may moderate the association between biological sex and experimental pain sensitivity. One hundred and fifty-two healthy adults (mean age = 22yrs., 53% males) were measured for cold pressor task (CPT) pain sensitivity (i.e., intensity ratings) and core aspects of social networks (e.g., proportion of friends vs. family, affection, affirmation, and aid). Results showed consistent sex differences in how social network structures and intimate relationship functioning modulated pain sensitivity. Females showed higher pain sensitivity when their social networks consisted of a higher proportion of intimate types of relationship partners (e.g., kin vs. non kin), when they had known their network partners for a longer period of time, and when they reported higher levels of logistical support from their significant other (e.g., romantic partner). Conversely, males showed distinct patterns in the opposite direction, including an association between higher levels of logistical support from one's significant other and lower CPT pain intensity. These findings show for the first time that the direction of sex differences in exogenous pain sensitivity is likely dependent on fundamental components of the individual's social environment. The utility of a social-signaling perspective of pain behaviors for examining, comparing, and interpreting individual and group differences in experimental and clinical pain reports is discussed.

  20. Sex-independent suppression of experimental inflammatory pain by minocycline in two mouse strains.

    PubMed

    Bastos, Leandro F S; Prazeres, Júlia D M; Godin, Adriana M; Menezes, Raquel R; Soares, Darly G; Ferreira, Wallace C; Dutra, Marcela M G B; Machado, Renes R; Coelho, Márcio M

    2013-10-11

    The research on sex differences in nociception and antinociception as well as sex and gender differences in pain and analgesia is a maturing field. There is a vast literature showing experimental and clinical pain suppressive effects induced by minocycline, especially in inflammatory pain. However, as far as we know, possible qualitative or quantitative sex differences in those effects remained to be examined. By employing the formalin test, which has two phases of experimental pain behavior that models nociceptive pain (i.e., first phase) and inflammatory pain (i.e., second phase), we initially evaluated the effect induced by minocycline in female or male C57BL/6 mice. The treatment reduced the second phase of licking behavior in both females and males, and the effects were quantitatively similar in both sexes. Likewise, the same sex-independent effect was observed in Swiss mice, suggesting a genotype-unspecific sex-independent effect. While minocycline is already being tested in clinical trials, this appears to be the first preclinical investigation of sex differences in the experimental pain suppressive effects induced by this widely studied drug. The independence of sex in the antinociceptive effect induced by minocycline may be hopefully translated to gender-independent analgesic effects, which would be surely promising in a therapeutic paradigm. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  1. Peripheral sensory neuron injury contributes to neuropathic pain in experimental autoimmune encephalomyelitis

    PubMed Central

    Wang, I-Ching; Chung, Chen-Yen; Liao, Fang; Chen, Chih-Cheng; Lee, Cheng-Han

    2017-01-01

    Multiple sclerosis (MS)-induced neuropathic pain deteriorates quality of life in patients but is often refractory to treatment. In experimental autoimmune encephalomyelitis (EAE), a rodent model of MS, animals develop neuropathy and inflammation-induced tissue acidosis, which suggests the involvement of acid-sensing ion channels (ASICs). Also, peripheral neuropathy is reported in MS patients. However, the involvement of the peripheral nervous system (PNS) in MS neuropathic pain remains elusive. This study investigated the contribution of ASICs and peripheral neuropathy in MS-induced neuropathic pain. Elicited pain levels were as high in Asic1a−/−, Asic2−/− and Asic3−/− mice as wild-type mice even though only Asic1a−/− mice showed reduced EAE disease severity, which indicates that pain in EAE was independent of disease severity. We thus adopted an EAE model without pertussis toxin (EAEnp) to restrain activated immunity in the periphery and evaluate the PNS contribution to pain. Both EAE and EAEnp mice showed similar pain behaviors and peripheral neuropathy in nerve fibers and DRG neurons. Moreover, pregabalin significantly reduced neuropathic pain in both EAE and EAEnp mice. Our findings highlight the essential role of the PNS in neuropathic pain in EAE and pave the way for future development of analgesics without side effects in the CNS. PMID:28181561

  2. Tryptase-PAR2 axis in experimental autoimmune prostatitis, a model for chronic pelvic pain syndrome.

    PubMed

    Roman, Kenny; Done, Joseph D; Schaeffer, Anthony J; Murphy, Stephen F; Thumbikat, Praveen

    2014-07-01

    Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) affects up to 15% of the male population and is characterized by pelvic pain. Mast cells are implicated in the murine experimental autoimmune prostatitis (EAP) model as key to chronic pelvic pain development. The mast cell mediator tryptase-β and its cognate receptor protease-activated receptor 2 (PAR2) are involved in mediating pain in other visceral disease models. Prostatic secretions and urines from CP/CPPS patients were examined for the presence of mast cell degranulation products. Tryptase-β and PAR2 expression were examined in murine EAP. Pelvic pain and inflammation were assessed in the presence or absence of PAR2 expression and upon PAR2 neutralization. Tryptase-β and carboxypeptidase A3 were elevated in CP/CPPS compared to healthy volunteers. Tryptase-β was capable of inducing pelvic pain and was increased in EAP along with its receptor PAR2. PAR2 was required for the development of chronic pelvic pain in EAP. PAR2 signaling in dorsal root ganglia led to extracellular signal-regulated kinase (ERK)1/2 phosphorylation and calcium influx. PAR2 neutralization using antibodies attenuated chronic pelvic pain in EAP. The tryptase-PAR2 axis is an important mediator of pelvic pain in EAP and may play a role in the pathogenesis of CP/CPPS.

  3. Social comparison performance standards, threat, and tolerance for experimentally-induced pain.

    PubMed

    Jackson, Todd; Phillips, Heath

    2011-11-01

    Social modelling experiments have illustrated how upward social comparisons (i.e., observing pain tolerant role models) can facilitate tolerance relative to downward social comparison (i.e., observing pain intolerant alternatives). However, because clinical studies suggest that people prefer to make downward social comparisons with less fortunate others when they are threatened or overwhelmed with pain or illness, it seems plausible that upward social comparisons confer fewer benefits when pain is appraised as threatening. To address this issue, we assessed effects of verbally-presented upward and downward social comparison standards on tolerance for cold pressor pain among 124 Australian adults (44 men, 80 women) primed with either more or less threatening orienting information about task-related pain sensations. As predicted, participants exposed to the lower threat orienting prime and upward comparison performance standard were significantly more pain tolerant than peers in all other conditions. Conversely, the average tolerance time for participants presented with the higher threat orienting prime and upward comparison standard did not differ from that of either downward comparison group. The research highlighted powerful situational influences on tolerance for experimental pain and identified conditions under which verbally-presented upward social comparison standards may facilitate and hinder the capacity to bear pain.

  4. Experimental endotoxemia as a model to study neuroimmune mechanisms in human visceral pain.

    PubMed

    Benson, Sven; Engler, Harald; Schedlowski, Manfred; Elsenbruch, Sigrid

    2012-07-01

    The administration of bacterial endotoxin (i.e., lipopolysaccharide, LPS) constitutes a well-established experimental approach to study the effects of an acute and transient immune activation on physiological, behavioral, and emotional aspects of sickness behavior in animals and healthy humans. However, little is known about possible effects of experimental endotoxemia on pain in humans. This knowledge gap is particularly striking in the context of visceral pain in functional as well as chronic-inflammatory gastrointestinal disorders. Although inflammatory processes have been implicated in the pathophysiology of visceral pain, it remains incompletely understood how inflammatory mediators interact with bottom-up (i.e., increased afferent input) and top-down (i.e., altered central pain processing) mechanisms of visceral hyperalgesia. Considering the recent findings of visceral hyperalgesia after LPS application in humans, in this review, we propose that experimental endotoxemia with its complex peripheral and central effects constitutes an experimental model to study neuroimmune communication in human pain research. We summarize and attempt to integrate relevant animal and human studies concerning neuroimmune communication in visceral and somatic pain, discuss putative mechanisms, and conclude with future research directions. © 2012 New York Academy of Sciences.

  5. [Patient first - The impact of characteristics of target populations on decisions about therapy effectiveness of complex interventions: Psychological variables to assess effectiveness in interdisciplinary multimodal pain therapy].

    PubMed

    Kaiser, Ulrike; Sabatowski, Rainer; Balck, Friedrich

    2017-08-01

    The assessment of treatment effectiveness in public health settings is ensured by indicators that reflect the changes caused by specific interventions. These indicators are also applied in benchmarking systems. The selection of constructs should be guided by their relevance for affected patients (patient reported outcomes). The interdisciplinary multimodal pain therapy (IMPT) is a complex intervention based on a biopsychosocial understanding of chronic pain. For quality assurance purposes, psychological parameters (depression, general anxiety, health-related quality of life) are included in standardized therapy assessment in pain medicine (KEDOQ), which can also be used for comparative analyses in a benchmarking system. The aim of the present study was to investigate the relevance of depressive symptoms, general anxiety and mental quality of life in patients undergoing IMPT under real life conditions. In this retrospective, one-armed and exploratory observational study we used secondary data of a routine documentation of IMST in routine care, applying several variables of the German Pain Questionnaire and the facility's comprehensive basic documentation. 352 participants with IMPT (from 2006 to 2010) were included, and the follow-up was performed over two years with six assessments. Because of statistically heterogeneous characteristics a complex analysis consisting of factor and cluster analyses was applied to build subgroups. These subgroups were explored to identify differences in depressive symptoms (HADS-D), general anxiety (HADS-A), and mental quality of life (SF 36 PSK) at the time of therapy admission and their development estimated by means of effect sizes. Analyses were performed using SPSS 21.0®. Six subgroups were derived and mainly proved to be clinically and psychologically normal, with the exception of one subgroup that consistently showed psychological impairment for all three parameters. The follow-up of the total study population revealed medium

  6. Ethnicity Interacts with the OPRM1 Gene in Experimental Pain Sensitivity

    PubMed Central

    Hastie, Barbara A.; Riley, Joseph L.; Kaplan, Lee; Herrera, Dyanne G.; Campbell, Claudia M.; Virtusio, Kathrina; Mogil, Jeffrey S.; Wallace, Margaret R.; Fillingim, Roger B.

    2013-01-01

    Robust inter-individual variation in pain sensitivity has been observed and recent evidence suggests that some of the variability may be genetically-mediated. Our previous data revealed significantly higher pressure pain thresholds among individuals possessing the minor G allele of the A118G SNP of the mu-opioid receptor gene (OPRM1) compared to those with two consensus alleles. Moreover, ethnic differences in pain sensitivity have been widely reported. Yet, little is known about the potential interactive associations of ethnicity and genotype with pain perception. This study aimed to identify ethnic differences in OPRM1 allelic associations with experimental pain responses. Two-hundred and forty-seven healthy young adults from three ethnic groups (81 African Americans; 79 non-white Hispanics; and 87 non-Hispanic whites) underwent multiple experimental pain modalities (thermal, pressure, ischemic, cold pressor). Few African Americans (7.4%) expressed the rare allele of OPRM1 compared to non-Hispanic-whites and Hispanics (28.7% vs. 27.8%, respectively). Across the entire sample, OPRM1 genotype did not significantly affect pain sensitivity. However, analysis in each ethnic group separately revealed significant genotype effects for most pain modalities among non-Hispanic-whites (ps<0.05) but not Hispanics or African Americans. The G allele was associated with decreased pain sensitivity among whites only; a trend in the opposite direction emerged in Hispanics. The reasons for this dichotomy are unclear but may involve ethnic differences in haplotypic structure or A118G may be a tag-SNP linked to other functional polymorphisms. These findings demonstrate an ethnic-dependent association of OPRM1 genotype with pain sensitivity. Additional research is warranted to uncover the mechanisms influencing these relationships. PMID:22717102

  7. Gender role affects experimental pain responses: a systematic review with meta-analysis.

    PubMed

    Alabas, O A; Tashani, O A; Tabasam, G; Johnson, M I

    2012-10-01

    Gender role refers to the culturally and socially constructed meanings that describe how women and men should behave in certain situations according to feminine and masculine roles learned throughout life. The aim of this meta-analysis was to evaluate the relationship between gender role and experimental pain responses in healthy human participants. We searched computerized databases for studies published between January 1950 and May 2011 that had measured gender role in healthy human adults and pain response to noxious stimuli. Studies were entered into a meta-analysis if they calculated a correlation coefficient (r) for gender role and experimental pain. Searches yielded 4465 'hits' and 13 studies were eligible for review. Sample sizes were 67-235 participants and the proportion of female participants was 45-67%. Eight types of gender role instrument were used. Meta-analysis of six studies (406 men and 539 women) found a significant positive correlation between masculine and feminine personality traits and pain threshold and tolerance, with a small effect size (r = 0.17, p = 0.01). Meta-analysis of four studies (263 men and 297 women) found a significant negative correlation between gender stereotypes specific to pain and pain threshold and tolerance, with a moderate effect size (r = -0.41, p < 0.001). In conclusion, individuals who considered themselves more masculine and less sensitive to pain than the typical man showed higher pain thresholds and tolerances. Gender stereotypes specific to pain scales showed stronger associations with sex differences in pain sensitivity response than masculine and feminine personality trait scales.

  8. A quantitative review of ethnic group differences in experimental pain response: do biology, psychology, and culture matter?

    PubMed

    Rahim-Williams, Bridgett; Riley, Joseph L; Williams, Ameenah K K; Fillingim, Roger B

    2012-04-01

    Pain is a subjectively complex and universal experience. We examine research investigating ethnic group differences in experimental pain response and factors contributing to group differences. We conducted a systematic literature review and analysis of studies using experimental pain stimuli to assess pain sensitivity across multiple ethnic groups. Our search covered the period from 1944 to 2011, and used the PubMed bibliographic database; a reference source containing over 17 million citations. We calculated effect sizes; identified ethnic/racial group categories, pain stimuli, and measures; and examined findings regarding biopsychosociocultural factors contributing to ethnic/racial group differences. We found 472 studies investigating ethnic group differences and pain. Twenty-six of these met our review inclusion criteria of investigating ethnic group differences in experimental pain. The majority of studies included comparisons between African Americans (AA) and non-Hispanic Whites (NHW). There were consistently moderate to large effect sizes for pain tolerance across multiple stimulus modalities; AA demonstrated lower pain tolerance. For pain threshold, findings were generally in the same direction, but effect sizes were small to moderate across ethnic groups. Limited data were available for suprathreshold pain ratings. A subset of studies comparing NHW and other ethnic groups showed a variable range of effect sizes for pain threshold and tolerance. There are potentially important ethnic/racial group differences in experimental pain perception. Elucidating ethnic group differences has translational merit for culturally competent clinical care and for addressing and reducing pain treatment disparities among ethnically/racially diverse groups. Wiley Periodicals, Inc.

  9. Development of a behavior model of pain induced by experimental tooth movement in rats.

    PubMed

    Yang, Zhi; Luo, Wei; Hou, Jingqiu; Zhao, Zhihe; Jian, Fan; Wamalwa, Peter; Lai, Wenli; Wang, Jing; Wang, Yan; Liao, Zhenyu

    2009-08-01

    The mechanism of orthodontic pain and discomfort is poorly understood partly because of the limited number of animal behavioral models for pain assessment. This study aimed to develop a behavioral model for assessment of tooth-movement pain in rats using directed face-grooming activity. Male Sprague-Dawley rats weighing 200-300 g were used. They were videotaped on days 1, 3, 5, 7, and 14 after experimental tooth movement and their directed face-grooming behavior was evaluated. In addition, we also evaluated behavioral responses to the application of a progressively higher magnitude force and to multiple applications of an equal magnitude force. Finally, the effects of peripherally and systemically administered morphine and of the N-methyl-d-aspartate (NMDA) receptor antagonist, MK-801, on the behavioral responses were evaluated. The results indicated that time spent on directed face-grooming activity increased dramatically after initiating experimental tooth movement. The change concurred with the initial orthodontic pain response. This behavioral change was reproducible and was related to force magnitude. Application of both systemic and peripheral morphine and MK-801 could exert an analgesic effect on this pain model. These results suggest that directed face-grooming behavior can be a reliable measure for tooth-movement pain in rats, which could be widely used in investigating the orthodontic pain mechanism.

  10. Changes in pain catastrophizing predict later changes in fibromyalgia clinical and experimental pain report: cross-lagged panel analyses of dispositional and situational catastrophizing

    PubMed Central

    2012-01-01

    Introduction Fibromyalgia (FM), characterized by wide-spread diffuse pain and sensory abnormalities, is associated with elevated indices of distress and pain-related catastrophizing compared to both pain-free samples and those with chronic pain conditions. Catastrophizing is a pervasive negative mental set, and is a strong predictor of negative pain-related outcomes such as clinical pain intensity, and physical disability. Situational catastrophizing, measured in the context of experimentally-induced pain, is strongly related to enhanced pain sensitivity, a core aspect of the pathophysiology of fibromyalgia. However, little is known regarding the temporal course of the association between catastrophizing and pain-related "outcomes". Most studies involve only static assessments of pain and catastrophizing at a single time point, which provides little insight into the direction of the observed associations. We sought to investigate the temporal relationships between catastrophizing and indices of both clinical pain (substudy 1) and experimentally-induced pain (substudy 2) in a larger randomized controlled longitudinal trial. Methods Fifty-seven patients with FM completed catastrophizing, depression, and pain questionnaires as well as laboratory cold pressor pain testing at baseline, post-intervention and three month follow-up during a lifestyle physical activity study. Cross-lagged panel analyses were used to address these temporal relationships. Results In substudy 1, analyses revealed that pre-to-post changes in dispositional catastrophizing ratings prospectively accounted for unique variance in subsequent post-to-follow-up changes in clinical pain ratings (p = 0.005), while pre-to-post changes in pain ratings did not account for unique variance in post-to-follow-up changes in catastrophizing ratings. An identical pattern was observed experimentally in substudy 2, with pre-to-post changes in situational catastrophizing ratings prospectively accounting for unique

  11. Comparison of location, depth, quality, and intensity of experimentally induced pain in 6 low back muscles.

    PubMed

    Tucker, Kylie J; Fels, Matthew; Walker, Scott R; Hodges, Paul W

    2014-09-01

    The pattern of pain originating from experimentally induced low back pain appears diffuse. This may be because sensory information from low back muscles converges, sensory innervation extends over multiple vertebral levels, or people have difficulty accurately representing the painful location on standardized pain maps. The aim of this study was to provide insight into the perception of pain from noxious stimulation of a range of low back muscles using novel depth and location measures. Hypertonic saline (1 mL, 7% NaCl) was injected into bellies of longissimus (LO), quadratus lumborum (QL), superficial multifidus (SM), and deep multifidus (DM) at the level of the fourth lumbar vertebrae (L4) and in SM and DM at L5 using ultrasound guidance over 6 sessions. Fifteen participants reported depth, location, intensity, size, and descriptive quality of pain throughout the painful period (∼14 min). Pain was reported deeper (P<0.04) for DML4/L5 compared with SML4/L5, LO and QL; more cranial for LO compared with DML4 and QL (P<0.01); more lateral for LO compared with DML4 (P<0.02); and more lateral for QL compared with all other muscles at L4 (P<0.0001). Pain intensity was higher in DML4/L5 than all other muscles (P<0.04) for ∼3 minutes. Descriptive qualities varied slightly between muscles. Depth and lateral position may be the most critical descriptors to determine the source of acute lumbar muscular pain. Overlapping regions of pain may be explained by convergence of receptive fields, innervation of multifidus fascicles at multiple lumbar segments, and convergence of sensory input from different muscles to the same sensory cell bodies as demonstrated in the lumbar spine of animal preparations.

  12. No effect of a single session of transcranial direct current stimulation on experimentally induced pain in patients with chronic low back pain--an exploratory study.

    PubMed

    Luedtke, Kerstin; May, Arne; Jürgens, Tim P

    2012-01-01

    Transcranial direct current stimulation (tDCS) has been shown to modulate cortical excitability. A small number of studies suggested that tDCS modulates the response to experimental pain paradigms. No trials have been conducted to evaluate the response of patients already suffering from pain, to an additional experimental pain before and after tDCS. The present study investigated the effect of a single session of anodal, cathodal and sham stimulation (15 mins/1 mA) over the primary motor cortex on the perceived intensity of repeated noxious thermal and electrical stimuli and on elements of quantitative sensory testing (thermal pain and perception thresholds) applied to the right hand in 15 patients with chronic low back pain. The study was conducted in a double-blind sham-controlled and cross-over design. No significant alterations of pain ratings were found. Modalities of quantitative sensory testing remained equally unchanged. It is therefore hypothesized that a single 15 mins session of tDCS at 1 mA may not be sufficient to alter the perception of experimental pain and in patients with chronic pain. Further studies applying repetitive tDCS to patients with chronic pain are required to fully answer the question whether experimental pain perception may be influenced by tDCS over the motor cortex.

  13. No Effect of a Single Session of Transcranial Direct Current Stimulation on Experimentally Induced Pain in Patients with Chronic Low Back Pain – An Exploratory Study

    PubMed Central

    Luedtke, Kerstin; May, Arne; Jürgens, Tim P.

    2012-01-01

    Transcranial direct current stimulation (tDCS) has been shown to modulate cortical excitability. A small number of studies suggested that tDCS modulates the response to experimental pain paradigms. No trials have been conducted to evaluate the response of patients already suffering from pain, to an additional experimental pain before and after tDCS. The present study investigated the effect of a single session of anodal, cathodal and sham stimulation (15 mins/1 mA) over the primary motor cortex on the perceived intensity of repeated noxious thermal and electrical stimuli and on elements of quantitative sensory testing (thermal pain and perception thresholds) applied to the right hand in 15 patients with chronic low back pain. The study was conducted in a double-blind sham-controlled and cross-over design. No significant alterations of pain ratings were found. Modalities of quantitative sensory testing remained equally unchanged. It is therefore hypothesized that a single 15 mins session of tDCS at 1 mA may not be sufficient to alter the perception of experimental pain and in patients with chronic pain. Further studies applying repetitive tDCS to patients with chronic pain are required to fully answer the question whether experimental pain perception may be influenced by tDCS over the motor cortex. PMID:23189136

  14. Noneffect of manual needle acupuncture on experimental pain parameters in healthy young men.

    PubMed

    Micalos, Peter S; Pak, Sok Cheon

    2011-01-01

    The purpose of this study is to assess the effect of manual acupuncture on experimental pain parameters in healthy participants. The experimental design was a repeated-measures, three-group pre- and postprocedure. All subjects participated in a control, sham, and acupuncture procedure, separated by 1 week, in a counterbalanced sequence to forestall an order effect. Data were collected in a laboratory environment. The participants included 12 healthy young men (mean age 21.3 ± 2.6 years; height 183.8 ± 5 cm; weight 77.7 ± 9.5 kg). The control procedure comprised assessing the experimental pain parameters before and after a quiet rest for 20 minutes. The sham procedure was performed with the needle inserted bilaterally 1-1.5 cm outside each acupoint. The manual acupuncture procedure was performed at two bilateral acupoints of LI-4 (Large Intestine 4, Hegu) and ST-44 (Stomach 44, Nei Ting). Pain parameters assessed included the pain threshold, nociceptive reflex threshold, and nociceptive reflex amplitude. Repeated-measures analysis of variance between pre- and postcontrol, sham, and acupuncture procedures for pain threshold, nociceptive reflex threshold, and nociceptive reflex amplitude revealed no significant difference. Manual acupuncture at bilateral acupoints LI-4 and ST-44 did not show a change in pain threshold, nociceptive flexion reflex threshold, or the nociceptive reflex amplitude in healthy participants.

  15. Mere intention to perform painful movements elicits fear of movement-related pain: an experimental study on fear acquisition beyond actual movements.

    PubMed

    Meulders, Ann; Vlaeyen, Johan W S

    2013-04-01

    Fresh empirical evidence supports the notion that fear of movement-related pain can be acquired through associative learning. In the context of these findings, 2 ideas are appealing, yet uninvestigated. The first is that merely the intention to perform a painful movement acts as a covert conditioned stimulus (CS) inducing defensive fear responses (ie, gaining excitatory properties following Pavlovian acquisition). The second idea is that after extinction, fear of movement-related pain can easily be reinstated after unexpected painful stimuli (ie, reinstatement). In a voluntary differential conditioning movement paradigm with movements as CSs and a painful electrocutaneous stimulus as the unconditioned stimulus (pain-US), 2 groups were included (Experimental/Control). One movement (CS+) was followed by the pain-US and another movement (CS-) was not during acquisition, while the CS+ was no longer reinforced during extinction. Next, the Experimental group received 2 reinstating pain-USs, whereas the Control group did not. The CS+ but not the CS- evoked fear of movement-related pain in self-reports and eye-blink startles. Intriguingly, the mere intention to perform the painful movement produced higher eye-blink startle responses than the intention to perform the nonpainful movement. We also demonstrated nondifferential reinstatement in the verbal fear ratings in the Experimental group only. This study demonstrates that the mere intention to perform a painful movement prior to the actual painful movement itself can come to elicit conditioned fear responses. These results suggest that actual movement may not be necessary to elicit pain-related fear responses, maintaining chronic pain-related fear, avoidance, and disability. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  16. Is multimodal care effective for the management of patients with whiplash-associated disorders or neck pain and associated disorders? A systematic review by the Ontario Protocol for Traffic Injury Management (OPTIMa) Collaboration.

    PubMed

    Sutton, Deborah A; Côté, Pierre; Wong, Jessica J; Varatharajan, Sharanya; Randhawa, Kristi A; Yu, Hainan; Southerst, Danielle; Shearer, Heather M; van der Velde, Gabrielle M; Nordin, Margareta C; Carroll, Linda J; Mior, Silvano A; Taylor-Vaisey, Anne L; Stupar, Maja

    2016-12-01

    Little is known about the effectiveness of multimodal care for individuals with whiplash-associated disorders (WAD) and neck pain and associated disorders (NAD). To update findings of the Bone and Joint Decade 2000-2010 Task Force on Neck Pain and Its Associated Disorders and evaluate the effectiveness of multimodal care for the management of patients with WAD or NAD. Systematic review and best-evidence synthesis. We included randomized controlled trials (RCTs), cohort studies, and case-control studies. Self-rated recovery, functional recovery (eg, disability, return to activities, work, or school), pain intensity, health-related quality of life, psychological outcomes (eg, depression, fear), or adverse events. We systematically searched five electronic databases (MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Central Register of Controlled Trials) from 2000 to 2013. RCTs, cohort, and case-control studies meeting our selection criteria were eligible for critical appraisal. Random pairs of independent reviewers critically appraised eligible studies using the Scottish Intercollegiate Guidelines Network criteria. Scientifically admissible studies were summarized using evidence tables and synthesized following best-evidence synthesis principles. We retrieved 2,187 articles, and 23 articles were eligible for critical appraisal. Of those, 18 articles from 14 different RCTs were scientifically admissible. There were a total of 31 treatment arms, including 27 unique multimodal programs of care. Overall, the evidence suggests that multimodal care that includes manual therapy, education, and exercise may benefit patients with grades I and II WAD and NAD. General practitioner care that includes reassurance, advice to stay active, and resumption of regular activities may be an option for the early management of WAD grades I and II. Our synthesis suggests that patients receiving high-intensity health care tend to experience poorer outcomes than those who receive fewer

  17. Women with dysmenorrhoea are hypersensitive to experimentally induced forearm ischaemia during painful menstruation and during the pain-free follicular phase.

    PubMed

    Iacovides, S; Avidon, I; Baker, F C

    2015-07-01

    Monthly primary dysmenorrhoeic pain is associated with increased sensitivity to painful stimuli, particularly in deep tissue. We investigated whether women with dysmenorrhoea, compared with controls, have increased sensitivity to experimentally induced deep-tissue muscle ischaemia in a body area distant from that of referred menstrual pain. The sub-maximal effort tourniquet test was used to induce forearm ischaemia in 11 women with severe dysmenorrhoea and in nine control women both during menstruation and in the follicular phase of the menstrual cycle. Von Frey hair assessments confirmed the presence of experimental ischaemia. Women rated the intensity of menstrual and ischaemic pain on a 100-mm visual analogue scale. Women with dysmenorrhoea [mean (SD): 68 (20) mm] reported significantly greater menstrual pain compared with controls [mean (SD): 2 (6) mm; p = 0.0001] during the menstruation phase. They also rated their forearm ischaemic pain as significantly greater than the controls during the menstruation [dysmenorrhoeics vs. controls mean (SD): 58 (19) mm vs. 31 (21) mm, p < 0.01] and follicular [dysmenorrhoeics vs. controls mean (SD): 60 (18) mm vs. 40 (14) mm, p < 0.01] phases of the menstrual cycle. These data show that compared with controls, women who experience severe recurrent dysmenorrhoea have deep-tissue hyperalgesia to ischaemic pain in muscles outside of the referred area of menstrual pain both during the painful menstruation phase and pain-free follicular phase. These findings suggest the presence of long-lasting changes in muscle pain sensitivity in women with dysmenorrhoea. Our findings that dysmenorrhoeic women are hyperalgesic to a clinically relevant, deep-muscle ischaemic pain in areas outside of referred menstrual pain confirm other studies showing long-lasting changes in pain sensitivity outside of the painful period during menstruation. © 2014 European Pain Federation - EFIC®

  18. Chemokine ligand 2 in the trigeminal ganglion regulates pain induced by experimental tooth movement.

    PubMed

    Yang, Zhi; Luo, Wei; Wang, Jing; Tan, Yu; Fu, Runqing; Fang, Bing

    2014-07-01

    To test the hypothesis that the chemokine ligand 2/chemokine receptor 2 (CCL2/CCR2) signaling pathway plays an important role in pain induced by experimental tooth movement. Expression of CCL2/CCR2 in the trigeminal ganglion (TG) was determined by Western blotting 0 hours, 4 hours, 1 day, 3 days, 5 days, and 7 days after tooth movement. CCL2 localization and cell size distribution were revealed by immunohistochemistry. The effects of increasing force on CCL2 expression and behavioral changes were investigated. Furthermore, the effects of CCL2/CCR2 antagonists on these changes in pain behaviors were all evaluated. Exogenous CCL2 was injected into periodontal tissues and cultured TG neurons with different concentrations, and then the pain responses or c-fos expression were assessed. Experimental tooth movement led to a statistically significant increase in CCL2/CCR2 expression from day 3 to day 7, especially in small to medium-sized TG neurons. It also triggered an increase in the time spent on directed face-grooming behaviors in a force magnitude-dependent and CCL2 dose-dependent manner. Pain induced by experimental tooth movement was effectively blocked by a CCR2 antagonist and by CCL2 neutralizing antibody. Also, exogenous CCL2 led to an increase in c-fos expression in cultured TG neurons, which was blocked by CCL2 neutralizing antibody. The peripheral CCL2/CCR2 axis is modulated by experimental tooth movement and involved in the development of tooth movement pain.

  19. The effect of spinal manipulative therapy on experimentally induced pain: a systematic literature review

    PubMed Central

    2012-01-01

    Background Although there is evidence that spinal manipulative therapy (SMT) can reduce pain, the mechanisms involved are not well established. There is a need to review the scientific literature to establish the evidence-base for the reduction of pain following SMT. Objectives To determine if SMT can reduce experimentally induced pain, and if so, if the effect is i) only at the level of the treated spinal segment, ii) broader but in the same general region as SMT is performed, or iii) systemic. Design A systematic critical literature review. Methods A systematic search was performed for experimental studies on healthy volunteers and people without chronic syndromes, in which the immediate effect of SMT was tested. Articles selected were reviewed blindly by two authors. A summary quality score was calculated to indicate level of manuscript quality. Outcome was considered positive if the pain-reducing effect was statistically significant. Separate evidence tables were constructed with information relevant to each research question. Results were interpreted taking into account their manuscript quality. Results Twenty-two articles were included, describing 43 experiments, primarily on pain produced by pressure (n = 27) or temperature (n = 9). Their quality was generally moderate. A hypoalgesic effect was shown in 19/27 experiments on pressure pain, produced by pressure in 3/9 on pain produced by temperature and in 6/7 tests on pain induced by other measures. Second pain provoked by temperature seems to respond to SMT but not first pain. Most studies revealed a local or regional hypoalgesic effect whereas a systematic effect was unclear. Manipulation of a “restricted motion segment” (“manipulable lesion”) seemed not to be essential to analgesia. In relation to outcome, there was no discernible difference between studies with higher vs. lower quality scores. Conclusions These results indicate that SMT has a direct local/regional hypoalgesic effect on

  20. Inflammation-induced pain sensitization in men and women: does sex matter in experimental endotoxemia?

    PubMed Central

    Wegner, Alexander; Elsenbruch, Sigrid; Rebernik, Laura; Roderigo, Till; Engelbrecht, Elisa; Jäger, Marcus; Engler, Harald; Schedlowski, Manfred; Benson, Sven

    2015-01-01

    Abstract A role of the innate immune system is increasingly recognized as a mechanism contributing to pain sensitization. Experimental administration of the bacterial endotoxin lipopolysaccharide (LPS) constitutes a model to study inflammation-induced pain sensitization, but all existing human evidence comes from male participants. We assessed visceral and musculoskeletal pain sensitivity after low-dose LPS administration in healthy men and women to test the hypothesis that women show greater LPS-induced hyperalgesia compared with men. In this randomized, double-blind, placebo-controlled crossover study, healthy men (n = 20) and healthy women using oral contraceptives (n = 20) received an intravenous injection of 0.4 ng/kg body weight LPS or placebo. Pain sensitivity was assessed with established visceral and musculoskeletal pain models (ie, rectal pain thresholds; pressure pain thresholds for different muscle groups), together with a heartbeat perception (interoceptive accuracy) task. Plasma cytokines (tumor necrosis factor-α and interleukin-6) were measured along with state anxiety at baseline and up to 6-hour postinjection. Lipopolysaccharide application led to significant increases in plasma cytokines and state anxiety and decreased interoceptive awareness in men and women (P < 0.001, condition effects), with more pronounced LPS-induced cytokine increases in women (P < 0.05, interaction effects). Although both rectal and pressure pain thresholds were significantly decreased in the LPS condition (all P < 0.05, condition effect), no sex differences in endotoxin-induced sensitization were observed. In summary, LPS-induced systemic immune activation leads to visceral and musculoskeletal hyperalgesia, irrespective of biological sex. These findings support the broad applicability of experimental endotoxin administration as a translational preclinical model of inflammation-induced pain sensitization in both sexes. PMID:26058036

  1. Inflammation-induced pain sensitization in men and women: does sex matter in experimental endotoxemia?

    PubMed

    Wegner, Alexander; Elsenbruch, Sigrid; Rebernik, Laura; Roderigo, Till; Engelbrecht, Elisa; Jäger, Marcus; Engler, Harald; Schedlowski, Manfred; Benson, Sven

    2015-10-01

    A role of the innate immune system is increasingly recognized as a mechanism contributing to pain sensitization. Experimental administration of the bacterial endotoxin lipopolysaccharide (LPS) constitutes a model to study inflammation-induced pain sensitization, but all existing human evidence comes from male participants. We assessed visceral and musculoskeletal pain sensitivity after low-dose LPS administration in healthy men and women to test the hypothesis that women show greater LPS-induced hyperalgesia compared with men. In this randomized, double-blind, placebo-controlled crossover study, healthy men (n = 20) and healthy women using oral contraceptives (n = 20) received an intravenous injection of 0.4 ng/kg body weight LPS or placebo. Pain sensitivity was assessed with established visceral and musculoskeletal pain models (ie, rectal pain thresholds; pressure pain thresholds for different muscle groups), together with a heartbeat perception (interoceptive accuracy) task. Plasma cytokines (tumor necrosis factor-α and interleukin-6) were measured along with state anxiety at baseline and up to 6-hour postinjection. Lipopolysaccharide application led to significant increases in plasma cytokines and state anxiety and decreased interoceptive awareness in men and women (P < 0.001, condition effects), with more pronounced LPS-induced cytokine increases in women (P < 0.05, interaction effects). Although both rectal and pressure pain thresholds were significantly decreased in the LPS condition (all P < 0.05, condition effect), no sex differences in endotoxin-induced sensitization were observed. In summary, LPS-induced systemic immune activation leads to visceral and musculoskeletal hyperalgesia, irrespective of biological sex. These findings support the broad applicability of experimental endotoxin administration as a translational preclinical model of inflammation-induced pain sensitization in both sexes.

  2. Effects of Experimental Pain and Lidocaine on Mechanical Somatosensory Profile and Face Perception.

    PubMed

    Costa, Yuri Martins; Castrillon, Eduardo E; Bonjardim, Leonardo Rigoldi; Rodrigues Conti, Paulo César; Baad-Hansen, Lene; Svensson, Peter

    2017-01-01

    To assess the effects of experimental muscle pain and topical lidocaine applied to the skin overlying the masseter muscle on the mechanical somatosensory profile and face perception of the masseter muscle in healthy participants. A total of 28 healthy participants received a 45-minute application of a lidocaine or placebo patch to the skin overlying the masseter muscle followed by one injection of 0.2 mL sterile solution of monosodium glutamate. Measurements were taken four times during each session of quantitative sensory testing (QST) (T0 = baseline, T1 = 45 minutes after patch application, T2 = immediately after glutamate injection, and T3 = 25 minutes after the glutamate injection), and the following variables were measured: mechanical detection threshold (MDT), mechanical pain threshold (MPT), pressure pain threshold (PPT), pain report (pain on palpation, pain spreading on palpation, and pain intensity), pain drawing, and perceptual distortion. Multi-way within-subjects analysis of variance (ANOVA) was applied to the data. The highest MDTs were present at T2 (F = 49.28, P < .001), the lowest PPTs were present at T2 and T3 (F = 21.78, P < .001), and the largest magnitude and area of perceptual distortion were reported at T2 (F > 6.48, P < .001). Short-lasting experimental muscle pain was capable of causing loss of tactile sensitivity as well as perceptual distortion of the face, regardless of preconditioning with a topical lidocaine patch. Short-term application of a lidocaine patch did not significantly affect the mechanical somatosensory profile.

  3. The effect of paracetamol and tropisetron on pain: experimental studies and a review of published data.

    PubMed

    Tiippana, Elina; Hamunen, Katri; Kontinen, Vesa; Kalso, Eija

    2013-02-01

    Experimental studies suggest that paracetamol-induced analgesia is mediated via central serotonergic pathways and attenuated by 5-HT3-antagonists. However, clinical studies do not support this, and 5-HT3-antagonists are expected to reduce pain by blocking the descending pronociceptive pathway. The current project tested whether tropisetron attenuates analgesia by paracetamol. Two randomized, double-blind, crossover studies with 18 healthy male volunteers in each were performed. Pain stimuli were cold water immersion (cold pressor test), contact heat pain (study 1) and electrical stimulation (study 2). In both studies, tropisetron 5 mg i.v. or saline was administered, followed by paracetamol 2 g i.v. 30 min. later. Individual changes in heat and cold pain intensity, cold pain tolerance and unpleasantness were recorded. The same thresholds were also expressed as scores (% of the individual score at baseline). Additionally, previously published findings on the effects of paracetamol and its interaction with 5HT3-antagonists in human experimental pain models were reviewed. After calculation of the sensory and pain scores (%), tropisetron seemed to amplify the analgesic action of paracetamol. Paracetamol 2 g i.v. did not show any statistically significant analgesia in thermal tests (study 1), or differences in sensory, pain detection or moderate pain thresholds of the electrical stimulus (study 2). As paracetamol did not have a measurable analgesic effect in these tests, no conclusions can be drawn about the interaction between paracetamol and tropisetron. However, tropisetron may have an analgesic effect of its own. Clinicians should not avoid using these drugs together, unless larger clinical studies indicate otherwise.

  4. TENS attenuates repetition-induced summation of activity-related pain following experimentally induced muscle soreness.

    PubMed

    Mankovsky-Arnold, Tsipora; Wideman, Timothy H; Larivière, Christian; Sullivan, Michael J L

    2013-11-01

    This study sought to determine whether repetition-induced summation of activity-related pain (RISP) could be demonstrated in healthy individuals in response to experimentally induced musculoskeletal pain. This study also assessed the effects of transcutaneous electrical nerve stimulation on RISP. The relation between the index of RISP and psychological factors such as catastrophizing and fear of pain was also explored. The sample consisted of 56 healthy (35 women, 21 men) participants who underwent 2 testing sessions, separated by 24 hours. In the first session, musculoskeletal pain was induced with a delayed-onset muscle soreness protocol. During the second session, participants were randomly assigned to the transcutaneous electrical nerve stimulation or placebo condition and were asked to rate their pain as they lifted a series of 18 weighted canisters. An index of RISP was derived as the change in pain ratings across repeated lifts. Approximately 25% of participants showed evidence of RISP. Results also revealed that transcutaneous electrical nerve stimulation attenuated the RISP effect. Psychological measures (fear of pain, catastrophizing) were not significantly correlated with the index of RISP, but the index of RISP was significantly correlated with a measure of physical tolerance. Discussion addresses the clinical implications of the findings as well as the potential mechanisms underlying RISP. This study showed that RISP could be demonstrated in healthy individuals in response to experimentally induced musculoskeletal pain with delayed-onset muscle soreness. Transcutaneous electrical nerve stimulation led to a significant reduction in RISP. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  5. Effect of transdermal opioids in experimentally induced superficial, deep and hyperalgesic pain.

    PubMed

    Andresen, T; Staahl, C; Oksche, A; Mansikka, H; Arendt-Nielsen, L; Drewes, A M

    2011-10-01

    Chronic pain and hyperalgesia can be difficult to treat with classical opioids acting predominately at the µ-opioid receptor. Buprenorphine and its active metabolite are believed to act through µ-, κ- and δ-receptors and may therefore possess different analgesic and anti-hyperalgesic effects compared with pure µ-receptor agonists, for example, fentanyl. Here, we have compared the analgesic and anti-hyperalgesic effects of buprenorphine and fentanyl. Twenty-two healthy volunteers were randomized to treatment with transdermal buprenorphine (20 µg·h(-1), 144 h), fentanyl (25 µg·h(-1), 72 h) or placebo patches in a double-blind, cross-over experimental pain study. The experimental pain tests (phasic pain, sensitization) involved pressure at the tibial bone, cutaneous electrical and thermal stimulation, intramuscular nerve growth factor, UVB light burn injury model and intradermal capsaicin-induced hyperalgesia. Pain testing was carried out at baseline, 24, 48, 72 and 144 h after application of the drugs. Compared with placebo, buprenorphine, but not fentanyl, significantly attenuated pressure at the tibial bone as well as pressure pain in the primary hyperalgesic area induced by UVB light The two drugs were equipotent and better than placebo against cutaneous thermal pain stimulation), but failed to show significant analgesic effect to cutaneous electrical stimulation, nerve growth factor-induced muscle soreness and to capsaicin-induced hyperalgesia. Buprenorphine, but not fentanyl, showed analgesic effects against experimentally induced, bone-associated pain and primary hyperalgesia compared with placebo. These tissue- and modality-differentiated properties may reflect the variable effects of opioid drugs observed in individual patients. © 2011 The Authors. British Journal of Pharmacology © 2011 The British Pharmacological Society.

  6. Antihypernociceptive activity of anethole in experimental inflammatory pain.

    PubMed

    Ritter, Alessandra M V; Domiciano, Talita P; Verri, Waldiceu A; Zarpelon, Ana Carla; da Silva, Lorena G; Barbosa, Carmem P; Natali, Maria Raquel M; Cuman, Roberto K N; Bersani-Amado, Ciomar A

    2013-04-01

    Anethole has been reported to have antioxidant, antibacterial, antifungal, antiinflammatory, and anesthetic properties. In the present study, we evaluated the effects of anethole in two pain models of inflammatory origin: acute inflammation induced by carrageenan and persistent inflammation induced by Complete Freund's adjuvant. We evaluated the effects of anethole (125, 250, and 500 mg/kg) on the development of paw oedema and mechanical hypernociception. The liver was collected for histological analysis. Paw skin was collected to determine the levels of the cytokines tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-17 (IL-17), and myeloperoxidase activity. Blood was collected to assess alanine transaminase (ALT) and aspartate transaminase (AST). The chemical composition of star anise oil was determined by gas chromatography/mass spectrometry (GC/MS), showing a presence of anethole of 98.1%. Oral pretreatment with anethole in mice inhibited paw oedema, mechanical pernociception, myelopewroxidase activity, TNF-α, IL-1β and IL-17 levels in acute and persistent inflammation models. Additionally, anethole treatment did not alter prostaglandin E2-induced mechanical hypernociception. Possible side effects were also examined. Seven-day anethole treatment did not alter plasma AST and ALT levels, and the histological profile of liver tissue was normal. The present study provides evidence of the antiinflammatory and analgesic activities of anethole in acute and persistent inflammation models.

  7. American Academy of Pain Medicine

    MedlinePlus

    ... More Essential Tools for Treating the Patient in Pain TM What Primary Care and Pain Specialists Need to Know Get Started Medications Management ... Whole Patient Get Started AAPM... the Voice of Pain Medicine Become part of the distinguished multimodal, interdisciplinary ...

  8. Neuronal and immunological basis of action of antidepressants in chronic pain - clinical and experimental studies.

    PubMed

    Mika, Joanna; Zychowska, Magdalena; Makuch, Wioletta; Rojewska, Ewelina; Przewlocka, Barbara

    2013-01-01

    The current knowledge of the pharmacological actions of the tricyclic antidepressants (TCAs) has slowly evolved through their over 40-year history. Chronic pain represents one of the most important public health problems, and antidepressants are an essential part of the therapeutic strategy in addition to classical analgesics. This article reviews the available evidence on the efficacy and safety of antidepressants in chronic pain conditions; namely, headaches, low back pain, fibromyalgia, cancer pain and especially neuropathic pain. TCAs are traditionally the main type of depression medication used to treat chronic pain. Recently, new antidepressants were introduced into clinical use, with a significant reduction in side effects and equivalent efficacy on mood disorders. These new drugs that are effective for chronic pain belong to the tetracyclic antidepressants (TeCAs) group (amoxapine, maprotiline), the serotonin and noradrenaline reuptake inhibitors (SNRIs) group (duloxetine, venlafaxine, milnacipran) and the atypical antidepressants group (bupropion, trazodone, mirtazapine, nefazodone). In this review, we present the available publications on TCAs (amitriptyline, doxepin, imipramine, desipramine, nortriptyline), TeCAs (amoxapine, maprotiline), selective serotonin reuptake inhibitors (SSRIs) (citalopram, fluoxetine, paroxetine), SNRIs (duloxetine, venlafaxine, milnacipran) and atypical antidepressants (bupropion) for the treatment of neuropathic pain. We also review analgesics acting as both opioid receptor agonists and also acting as aminergic reuptake inhibitors. Existing data are insufficient to conclude which of these new classes of antidepressants has the best clinical profile and will be the most effective in the treatment of neuropathic pain; in addition, a lower incidence of side effects should be considered. Increased experimental and translational research is a key for further improvement of the treatment of chronic pain with antidepressants. However

  9. Impact of a novel online learning module on specialist palliative care nurses' pain assessment competencies and patients' reports of pain: Results from a quasi-experimental pilot study.

    PubMed

    Phillips, Jane L; Heneka, Nicole; Hickman, Louise; Lam, Lawrence; Shaw, Tim

    2014-06-01

    Pain is a complex multidimensional phenomenon moderated by consumer, provider and health system factors. Effective pain management cuts across professional boundaries, with failure to screen and assess contributing to the burden of unrelieved pain. To test the impact of an online pain assessment learning module on specialist palliative care nurses' pain assessment competencies, and to determine whether this education impacted positively on palliative care patients' reported pain ratings. A quasi-experimental pain assessment education pilot study utilising 'Qstream(©)', an online methodology to deliver 11 case-based pain assessment learning scenarios, developed by an interdisciplinary expert panel and delivered to participants' work emails over a 28-day period in mid-2012. The 'Self-Perceived Pain Assessment Competencies' survey and chart audit data, including patient-reported pain intensity ratings, were collected pre-intervention (T1) and post-intervention (T2) and analysed using inferential statistics to determine key outcomes. Nurses working at two Australian inpatient specialist palliative care services in 2012. The results reported conform to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Guidelines. Participants who completed the education intervention ( n = 34) increased their pain assessment knowledge, assessment tool knowledge and confidence to undertake a pain assessment ( p < 0.001). Participants were more likely to document pain intensity scores in patients' medical records than non-participants (95% confidence interval = 7.3%-22.7%, p = 0.021). There was also a significant reduction in the mean patient-reported pain ratings between the admission and audit date at post-test of 1.5 (95% confidence interval = 0.7-2.3) units in pain score. This pilot confers confidence of the education interventions capacity to improve specialist palliative care nurses' pain assessment practices and to reduce patient-rated pain intensity

  10. The Role of Coping and Race in Healthy Children’s Experimental Pain Responses

    PubMed Central

    Evans, Subhadra; Lu, Qian; Tsao, Jennie C. I.; Zelter, Lonnie K.

    2009-01-01

    This study examined the relationship between race, laboratory-based coping strategies and anticipatory anxiety and pain intensity for cold, thermal (heat) and pressure experimental pain tasks. Participants were 123 healthy children and adolescents, including 33 African Americans (51% female; mean age =13.9 years) and 90 Caucasians (50% female; mean age = 12.6 years). Coping in response to the cold task was assessed with the Lab Coping Style interview; based on their interview responses, participants were categorized as ‘attenders’ (i.e., those who focused on the task) vs. ‘distractors’ (i.e., those who distracted themselves during the task). Analysis of covariance (ANCOVA) revealed significant interactions between race (African-American vs. Caucasian) and lab-based coping style after controlling for sex, age and socioeconomic status. African-American children classified as attenders reported less anticipatory anxiety for the cold task and lower pain intensity for the cold, heat and pressure tasks compared to those categorized as distractors. For these pain outcomes, Caucasian children classified as distractors reported less anticipatory anxiety and lower pain intensity relative to those categorized as attenders. The findings point to the moderating effect of coping in the relationship between race and experimental pain sensitivity. PMID:20352035

  11. Adult Stem Cell as New Advanced Therapy for Experimental Neuropathic Pain Treatment

    PubMed Central

    Franchi, Silvia; Castelli, Mara; Amodeo, Giada; Niada, Stefania; Ferrari, Daniela; Vescovi, Angelo; Brini, Anna Teresa; Panerai, Alberto Emilio; Sacerdote, Paola

    2014-01-01

    Neuropathic pain (NP) is a highly invalidating disease resulting as consequence of a lesion or disease affecting the somatosensory system. All the pharmacological treatments today in use give a long lasting pain relief only in a limited percentage of patients before pain reappears making NP an incurable disease. New approaches are therefore needed and research is testing stem cell usage. Several papers have been written on experimental neuropathic pain treatment using stem cells of different origin and species to treat experimental NP. The original idea was based on the capacity of stem cell to offer a totipotent cellular source for replacing injured neural cells and for delivering trophic factors to lesion site; soon the researchers agreed that the capacity of stem cells to contrast NP was not dependent upon their regenerative effect but was mostly linked to a bidirectional interaction between the stem cell and damaged microenvironment resident cells. In this paper we review the preclinical studies produced in the last years assessing the effects induced by several stem cells in different models of neuropathic pain. The overall positive results obtained on pain remission by using stem cells that are safe, of easy isolation, and which may allow an autologous transplant in patients may be encouraging for moving from bench to bedside, although there are several issues that still need to be solved. PMID:25197647

  12. Adult stem cell as new advanced therapy for experimental neuropathic pain treatment.

    PubMed

    Franchi, Silvia; Castelli, Mara; Amodeo, Giada; Niada, Stefania; Ferrari, Daniela; Vescovi, Angelo; Brini, Anna Teresa; Panerai, Alberto Emilio; Sacerdote, Paola

    2014-01-01

    Neuropathic pain (NP) is a highly invalidating disease resulting as consequence of a lesion or disease affecting the somatosensory system. All the pharmacological treatments today in use give a long lasting pain relief only in a limited percentage of patients before pain reappears making NP an incurable disease. New approaches are therefore needed and research is testing stem cell usage. Several papers have been written on experimental neuropathic pain treatment using stem cells of different origin and species to treat experimental NP. The original idea was based on the capacity of stem cell to offer a totipotent cellular source for replacing injured neural cells and for delivering trophic factors to lesion site; soon the researchers agreed that the capacity of stem cells to contrast NP was not dependent upon their regenerative effect but was mostly linked to a bidirectional interaction between the stem cell and damaged microenvironment resident cells. In this paper we review the preclinical studies produced in the last years assessing the effects induced by several stem cells in different models of neuropathic pain. The overall positive results obtained on pain remission by using stem cells that are safe, of easy isolation, and which may allow an autologous transplant in patients may be encouraging for moving from bench to bedside, although there are several issues that still need to be solved.

  13. Experimentally induced pain perception in men and women in the morning and evening.

    PubMed

    Koltyn, K F; Focht, B C; Ancker, J M; Pasley, J

    1999-01-01

    The literature regarding whether or not there are diurnal differences in pain perception in men and women is equivocal. The purpose of this study was to examine the influence of time of day on experimentally induced pain threshold in men and women. A secondary purpose was to measure selected psychological and physiological responses. Pressure (3000 gm force) was applied to the middle digit of the left forefinger for 2-min with the Forgione-Barber pain stimulator. Twenty-nine volunteers (women = 14; men = 15) completed two randomly assigned sessions between 6.00-8.00 in the AM and PM. Selected psychological variables (STAI,POMS) and physiological variables (BP, HR, TEMP) were assessed before application of the pressure stimulus. Data were analyzed with a 2x2 ANOVA. Results indicated that men had significantly higher (p<.05) systolic blood pressure and pain thresholds than women however, there was not a significant time of day effect for pain threshold. Significant time of day effects (p<.05) were found for systolic blood pressure and tympanic temperature. Heart rate, and tympanic temperature were found to be significantly higher (p<.05) in women in comparison to men. It is concluded that pain threshold did not differ in the AM and PM. Furthermore, men were found to have higher pain thresholds compared to the women.

  14. Experimental pain thresholds and plasma beta-endorphin levels during exercise.

    PubMed

    Droste, C; Greenlee, M W; Schreck, M; Roskamm, H

    1991-03-01

    Experimental pain thresholds (electrical intracutaneous finger and dental pulp stimulation) and plasma hormone levels (beta-endorphin, cortisol, and catecholamines) were measured in ten healthy sportive men before, during, and after progressively more strenuous physical exercise. In a double-blind study conducted on two different days, 20 mg of the opioid-antagonist naloxone or placebo was administered prior to exercise. A significant pain threshold elevation was found during exercise for finger (ANOVA, P less than 0.004) and dental pulp stimulation (P less than 0.01). Pain threshold elevation was most pronounced during maximal exertion, at which time the subjects reported the greatest subjective fatigue. Thresholds remained elevated 10-15 min after the end of exercise, and, 60 min after exercise, thresholds returned to baseline values. The subjective magnitude estimation of suprathreshold stimuli was significantly reduced (P less than 0.0001) 5-10 min after exercise. Plasma beta-endorphin, cortisol, and catecholamines increased significantly (P less than 0.0005, all values) during exercise. Plasma beta-endorphin levels did not correlate significantly with pain thresholds (r = -0.37, NS). Naloxone failed to affect pain thresholds, although beta-endorphin and cortisol increased significantly more (P less than 0.02) during exercise after naloxone. It is concluded that short-term, exhaustive physical exercise can evoke a transient elevation in pain thresholds. This exercise-induced elevation in pain threshold does not, however, appear to be directly related to plasma endorphin levels.

  15. Genetic predictors for acute experimental cold and heat pain sensitivity in humans

    PubMed Central

    Kim, H; Mittal, D P; Iadarola, M J; Dionne, R A

    2006-01-01

    Background The genetic contribution to pain sensitivity underlies a complex composite of parallel pain pathways, multiple mechanisms, and diverse inter‐individual pain experiences and expectations. Methods Variations for genes encoding receptors related to cold and heat sensation, such as transient receptor potential A subtype 1 (TRPA1), M subtype 8 (TRPM8), V subtype 1 (TRPV1), δ opioid receptor subtype 1 (OPRD1), catechol O‐methyltransferase (COMT), and fatty acid amide hydrolyase (FAAH), were investigated in four major ethnic populations. Results We defined 13 haplotype blocks in European Americans, seven blocks in African Americans, seven blocks in Hispanic subjects, and 11 blocks in Asian Americans. Further study in European American subjects found significant associations between short duration cold pain sensitivity and variations in TRPA1, COMT, and FAAH in a gender dependent manner. Our observations demonstrate that genetic variations in TRPA1, COMT, and FAAH contribute gender specifically to individual variations in short duration cold pain sensitivity in a European American cohort. Conclusions The effects of TRPA1 variations on experimental short duration heat pain sensitivity may contribute to inter‐individual variation in pain sensitivity in humans. PMID:16882734

  16. Effect of pulsed electromagnetic field therapy on experimental pain: A double-blind, randomized study in healthy young adults.

    PubMed

    Beaulieu, Karen; Beland, Patricia; Pinard, Marilee; Handfield, Guilène; Handfield, Nicole; Goffaux, Philippe; Corriveau, Hélène; Léonard, Guillaume

    2016-01-01

    Previous studies suggested that pulsed electromagnetic field (PEMF) therapy can decrease pain. To date, however, it remains difficult to determine whether the analgesic effect observed in patients are attributable to a direct effect of PEMF on pain or to an indirect effect of PEMF on inflammation and healing. In the present study, we used an experimental pain paradigm to evaluate the direct effect of PEMF on pain intensity, pain unpleasantness, and temporal summation of pain. Twenty-four healthy subjects (mean age 22 ± 2 years; 9 males) participated in the experiment. Both real and sham PEMF were administered to every participant using a randomized, double-blind, cross-over design. For each visit, PEMF was applied for 10 minutes on the right forearm using a portable device. Experimental pain was evoked before (baseline) and after PEMF with a 9 cm(2) Pelletier-type thermode, applied on the right forearm (120 s stimulation; temperature individually adjusted to produce moderate baseline pain). Pain intensity and unpleasantness were evaluated using a 0-100 numerical pain rating scale. Temporal summation was evaluated by comparing pain intensity ratings obtained at the end of tonic nociceptive stimulation (120 s) with pain intensity ratings obtained after 60 s of stimulation. When compared to baseline, there was no change in pain intensity and unpleasantness following the application of real or sham PEMF. PEMF did not affect temporal summation. The present observations suggest that PEMF does not directly influence heat pain perception in healthy individuals.

  17. The efficacy of multimodal high-volume wound infiltration in primary total knee replacement in facilitating immediate post-operative pain relief and attainment of early rehabilitation milestones.

    PubMed

    Banerjee, Purnajyoti

    2014-05-01

    Inadequate pain relief after lower limb joint replacement surgery has been a well-recognised limiting factor affecting post-operative mobilisation and length of hospital stay. Multimodal local wound infiltration with local anaesthetics, adrenaline and non-steroidal anti-inflammatory agents can lower the opiate intake, reduce the length of stay and enhance early mobilisation in knee replacement patients. A retrospective review of 64 patients undergoing primary total knee replacement was undertaken. Thirty-two patients (cases) had their wounds infiltrated with ropivacaine, adrenaline and ketorolac by the operating surgeon, intraoperatively. Subsequently, a 19G wound catheter placed into the knee joint. They received two further top-up doses of the same combination at 10 and 20 h post-operatively. This group was compared with a control group of 32 patients who did not receive any local infiltration. Both groups were comparable in terms of BMI and age. Post-operative opiate drug consumption in first 48 h after surgery, length of hospital stays and time taken to mobilise after surgery were recorded. There was significant reduction in opiate consumption in the treatment group with an average consumption of 49.35 mg of morphine compared to 71.48 mg in the control group (p = 0.004). The median length of hospital stay was significantly reduced from 5 days in the control group to 4 days in the treatment group (p = 0.03). The patients in the treatment group mobilised around 19 h earlier (p = 0.001). No major post-operative complications were encountered in either group. Wound infiltration is an effective and safe technique that promotes early rehabilitation and discharge of patients following primary total knee replacement.

  18. Comparison of acceptance and distraction strategies in coping with experimentally induced pain

    PubMed Central

    Moore, Hazel; Stewart, Ian; Barnes-Holmes, Dermot; Barnes-Holmes, Yvonne; McGuire, Brian E

    2015-01-01

    Background This study compared an acceptance-based strategy with a control-based strategy (distraction) in terms of the ability of participants to tolerate a painful stimulus, across two experiments. In addition, participants were either actively encouraged, or not, to link pain tolerance with pursuit of valued goals to examine the impact of pursuing a personally meaningful goal or value on the extent to which pain will be tolerated. Methods Participants in experiment 1 (n=41) and experiment 2 (n=52) were equally assigned to acceptance or distraction protocols. Further, half the participants in each group generated examples from their own lives in which they had pursued a valued objective, while the other half did not. In experiment 2, the values focus was enhanced to examine the impact on pain tolerance. Results There were no significant differences overall between the acceptance and distraction groups on pain tolerance in either experiment. However, in experiment 2, individuals classified as accepting in terms of general coping style and who were assigned to the acceptance strategy showed significantly better pain tolerance than accepting individuals who were in the distraction condition. Across both experiments, those with strong goal-driven values in both protocols were more tolerant of pain. Participants appeared to have more difficulty adhering to acceptance than to distraction as a strategy. Conclusion Acceptance may be associated with better tolerance of pain, but may also be more difficult to operationalize than distraction in experimental studies. Matching coping style and coping strategy may be most effective, and enhancement of goal-driven values may assist in pain coping. PMID:25834464

  19. The role of motivation in distracting attention away from pain: an experimental study.

    PubMed

    Verhoeven, Katrien; Crombez, Geert; Eccleston, Christopher; Van Ryckeghem, Dimitri M L; Morley, Stephen; Van Damme, Stefaan

    2010-05-01

    Research on the effectiveness of distraction as a method of pain control is inconclusive. One mechanism pertains to the motivational relevance of distraction tasks. In this study the motivation to engage in a distraction task during pain was experimentally manipulated. Undergraduate students (N=73) participated in a cold pressor test (CPT) and were randomly assigned to three groups: a distraction-only group performed a tone-detection task during the CPT, a motivated-distraction group performed the same task and received a monetary reward for good task performance, and a control group did not perform the tone-detection task. Results indicated that engagement in the distraction task was better in the motivated-distraction group in comparison with the distraction-only group. Participants in both distraction groups experienced less pain compared to the control group. There were no overall differences in pain intensity between the two distraction groups. The effect of distraction was influenced by the level of catastrophic thinking about pain. For low catastrophizers, both distraction groups reported less pain as compared to the non-distracted control group. This was not the case for high catastrophizers. For high catastrophizers it mattered whether the distraction task was motivationally relevant: high catastrophizers reported less intense pain in the motivated-distraction group, as compared to the non-distracted control group. We conclude that increasing the motivational relevance of the distraction task may increase the effects of distraction, especially for those who catastrophize about pain. Copyright 2010 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  20. Comparison of acceptance and distraction strategies in coping with experimentally induced pain.

    PubMed

    Moore, Hazel; Stewart, Ian; Barnes-Holmes, Dermot; Barnes-Holmes, Yvonne; McGuire, Brian E

    2015-01-01

    This study compared an acceptance-based strategy with a control-based strategy (distraction) in terms of the ability of participants to tolerate a painful stimulus, across two experiments. In addition, participants were either actively encouraged, or not, to link pain tolerance with pursuit of valued goals to examine the impact of pursuing a personally meaningful goal or value on the extent to which pain will be tolerated. Participants in experiment 1 (n=41) and experiment 2 (n=52) were equally assigned to acceptance or distraction protocols. Further, half the participants in each group generated examples from their own lives in which they had pursued a valued objective, while the other half did not. In experiment 2, the values focus was enhanced to examine the impact on pain tolerance. There were no significant differences overall between the acceptance and distraction groups on pain tolerance in either experiment. However, in experiment 2, individuals classified as accepting in terms of general coping style and who were assigned to the acceptance strategy showed significantly better pain tolerance than accepting individuals who were in the distraction condition. Across both experiments, those with strong goal-driven values in both protocols were more tolerant of pain. Participants appeared to have more difficulty adhering to acceptance than to distraction as a strategy. Acceptance may be associated with better tolerance of pain, but may also be more difficult to operationalize than distraction in experimental studies. Matching coping style and coping strategy may be most effective, and enhancement of goal-driven values may assist in pain coping.

  1. Emotional stress- and pain-related behaviors evoked by experimental tooth movement.

    PubMed

    Yozgatian, Joseph H; Zeredo, Jorge L; Hotokezaka, Hitoshi; Koga, Yoshiyuki; Toda, Kazuo; Yoshida, Noriaki

    2008-05-01

    To investigate by behavioral methods the relationship between emotional stress and pain during experimental tooth movement in rats. Sixteen male Sprague-Dawley rats (210 to 250 g) were divided into two groups. The experimental group was treated with an active Ti-Ni appliance, and the control group received a passive appliance. A force of 20 gf was delivered by the active appliance between the maxillary first and second molars for 3 days. During this period the rat's behavior was evaluated eight times by means of open-field test and resistance-to-capture test. The specific parameters of animal activity were facial grooming, rearing, and locomotor activity, movement into the center of the open field, and response to capture. Parameters related to stress and pain were higher in the group carrying active appliance, compared to the group with a passive appliance. Statistically significant differences in stress-related behavior between control and experimental groups were found 8 hours after placing the appliance and were most evident on the second day. Pain-related behavior was significantly greater in the experimental group than in the control group at 24 hours. The increase in emotional stress evoked by orthodontic tooth movement may precede the appearance of periodontal pain.

  2. The effect of experimental low back pain on lumbar muscle activity in people with a history of clinical low back pain: a muscle functional MRI study.

    PubMed

    Danneels, Lieven; Cagnie, Barbara; D'hooge, Roseline; De Deene, Yves; Crombez, Geert; Vanderstraeten, Guy; Parlevliet, Thierry; Van Oosterwijck, Jessica

    2016-02-01

    In people with a history of low back pain (LBP), structural and functional alterations have been observed at several peripheral and central levels of the sensorimotor pathway. These existing alterations might interact with the way the sensorimotor system responds to pain. We examined this assumption by evaluating the lumbar motor responses to experimental nociceptive input of 15 participants during remission of unilateral recurrent LBP. Quantitative T2 images (muscle functional MRI) were taken bilaterally of multifidus, erector spinae, and psoas at several segmental levels (L3 upper and L4 upper and lower endplate) and during several conditions: 1) at rest, 2) upon trunk-extension exercise without pain, and 3) upon trunk-extension exercise with experimental induced pain at the clinical pain-side (1.5-ml intramuscular hypertonic saline injections in erector spinae). Following experimental pain induction, muscle activity levels similarly reduced for all three muscles, on both painful and nonpainful sides, and at multiple segmental levels (P = 0.038). Pain intensity and localization from experimental LBP were similar as during recalled clinical LBP episodes. In conclusion, unilateral and unisegmental experimental LBP exerts a generalized and widespread decrease in lumbar muscle activity during remission of recurrent LBP. This muscle response is consistent with previous observed patterns in healthy people subjected to the same experimental pain paradigm. It is striking that similar inhibitory patterns in response to pain could be observed, despite the presence of preexisting alterations in the lumbar musculature during remission of recurrent LBP. These results suggest that motor output can modify along the course of recurrent LBP. Copyright © 2016 the American Physiological Society.

  3. The role of neuroplasticity in experimental neck pain: a study of potential mechanisms impeding clinical outcomes of training.

    PubMed

    Rittig-Rasmussen, Bjarne; Kasch, Helge; Fuglsang-Frederiksen, Anders; Svensson, Peter; Jensen, Troels Staehelin

    2014-08-01

    Training is a mainstay in the clinical management of neck pain, yet, effects of various training protocols are only small to moderate and improvements are required. Previous investigations of the nervous system indicate a correlation between neuroplastic adaptation to training and functional recovery. The interaction between neck pain and training thus needs further exploration. This was a randomized experimental study of the effects of experimental neck pain and training on corticomotor excitability. Healthy volunteers were randomized to training and experimental neck pain, training and no pain, and pain and no training. Primary endpoints were corticomotor excitability assessed by transcranial magnetic stimulation and electromyography measured as changes in amplitudes and latencies of motor evoked potentials (MEPs), recorded at baseline and after 30 min, 1 h, and 1 week. Additionally, correlations between changes in MEPs and motor learning, effects of pain and concomitant neck training on pain, muscle strength, and fatigue were investigated. Data were analyzed by repeated measurement ANOVA, paired t tests, Grubbs' outlier test and correlation coefficients. Results indicated that neck pain and training significantly enhanced the inhibition of the amplitudes of the MEPs for 1 week. The results indicate that moderate neck pain and training induce long-lasting inhibition of the corticomotor pathways. This inhibition may limit the outcome of neck training in painful conditions in contrast to pain-free training conditions.

  4. Antinociceptive effect of botulinum toxin type A on experimental abdominal pain.

    PubMed

    Drinovac, Višnja; Bach-Rojecky, Lidija; Babić, Ana; Lacković, Zdravko

    2014-12-15

    Visceral pain, especially in the abdominal region, represents one of the most common types of pain. Its chronic form is usually very hard to treat by conventional analgesic agents and adjuvants. We investigated the antinociceptive effect of botulinum toxin type A (BTX-A) in male Wistar rats in two models of visceral pain: peritonitis induced by intraperitoneal injection of 1% acetic acid and colitis induced by intracolonic instillation of 0.1% capsaicin. Pain was measured as the number of abdominal writhes. Additionally, referred mechanical sensitivity in the ventral abdominal area was evaluated by von Frey test and the extent of spinal c-Fos expression was immunohistochemically examined. BTX-A significantly reduced the number of abdominal writhes in both models of visceral pain after intrathecal application in a dose of 2 U/kg. In the experimental colitis model, BTX-A (2 U/kg) reduced both referred mechanical allodynia and c-Fos expression in the dorsal horn of the spinal cord (S2/S3 segments). In contrast to intrathecal administration, BTX-A (2 U/kg) administered into the cisterna magna had no effect on pain suggesting that the primary site of its action is a spinal cord.

  5. Effect of Experimental Cutaneous Hand Pain on Corticospinal Excitability and Short Afferent Inhibition

    PubMed Central

    Mercier, Catherine; Gagné, Martin; Reilly, Karen T.; Bouyer, Laurent J.

    2016-01-01

    Sensorimotor integration is altered in people with chronic pain. While there is substantial evidence that pain interferes with neural activity in primary sensory and motor cortices, much less is known about its impact on integrative sensorimotor processes. Here, the short latency afferent inhibition (SAI) paradigm was used to assess sensorimotor integration in the presence and absence of experimental cutaneous heat pain applied to the hand. Ulnar nerve stimulation was combined with transcranial magnetic stimulation to condition motor evoked potentials (MEPs) in the first dorsal interosseous muscle. Four interstimulus intervals (ISI) were tested, based on the latency of the N20 component of the afferent sensory volley (N20−5 ms, N20+2 ms, N20+4 ms, N20+10 ms). In the PAIN condition, MEPs were smaller compared to the NEUTRAL condition (p = 0.005), and were modulated as a function of the ISI (p = 0.012). Post-hoc planned comparisons revealed that MEPs at N20+2 and N20+4 were inhibited compared to unconditioned MEPs. However, the level of inhibition (SAI) was similar in the PAIN and NEUTRAL conditions. This suggests that the interplay between pain and sensorimotor integration is not mediated through direct and rapid pathways as assessed by SAI, but rather might involve higher-order integrative areas. PMID:27690117

  6. Preoccupation in an early-romantic relationship predicts experimental pain relief.

    PubMed

    Nilakantan, Aneesha; Younger, Jarred; Aron, Arthur; Mackey, Sean

    2014-06-01

    Individuals involved in the early stages of a passionate romantic relationship can be consumed by the experience and report emotional dependence and constant focus on their romantic partner. A few studies have shown that viewing pictures of a romantic partner can significantly reduce experimental pain. The strength of the effect, however, varies substantially between individuals. To study why some individuals experience significant pain reduction when looking at a picture of their partner, we examined partner preoccupation. We hypothesized that a greater degree of preoccupation in the early stages of a romantic relationship would be associated with greater analgesia during a pain induction task. Participants were shown pictures of their romantic partner or an equally attractive and familiar acquaintance while exposed to low, moderate, or high levels of thermal pain. Participants were also asked to rate how much time they spent thinking about their romantic partner during an average day. Degree of preoccupation was defined as the percentage of time participants spent thinking about their partner on an average day. In two separate experiments, viewing pictures of a romantic partner produced an analgesic effect. The degree of pain relief was positively correlated with partner preoccupation. The results suggest that preoccupation with a romantic partner during early stage romantic love is a predictor of pain relief when viewing pictures of the beloved. Wiley Periodicals, Inc.

  7. Preoccupation in an early-romantic relationship predicts experimental pain relief

    PubMed Central

    Nilakantan, Aneesha; Younger, Jarred; Aron, Arthur; Mackey, Sean

    2014-01-01

    Objective Individuals involved in the early stages of a passionate romantic relationship can be consumed by the experience and report emotional dependence and constant focus on their romantic partner. A few studies have shown that viewing pictures of a romantic partner can significantly reduce experimental pain. The strength of the effect, however, varies substantially between individuals. To study why some individuals experience significant pain reduction when looking at a picture of their partner, we examined partner preoccupation. We hypothesized that a greater degree of preoccupation in the early stages of a romantic relationship would be associated with greater analgesia during a pain induction task. Methods Participants were shown pictures of their romantic partner or an equally attractive and familiar acquaintance while exposed to low, moderate or high levels of thermal pain. Participants were also asked to rate how much time they spent thinking about their romantic partner during an average day. Degree of preoccupation was defined as the percentage of time participants spent thinking about their partner on an average day. Results In two separate experiments, viewing pictures of a romantic partner produced an analgesic effect. The degree of pain relief was positively correlated with partner preoccupation. The results suggest that preoccupation with a romantic partner during early stage romantic love is a predictor of pain relief when viewing pictures of the beloved. PMID:24716721

  8. Opioid treatment of experimental pain activates nuclear factor-κB

    PubMed Central

    Compton, Peggy; Griffis, Charles; Breen, Elizabeth Crabb; Torrington, Matthew; Sadakane, Ryan; Tefera, Eshetu; Irwin, Michael R.

    2015-01-01

    Objective To determine the independent and combined effects of pain and opioids on the activation of an early marker of inflammation, nuclear factor-κB (NF-κB). Design NF-κB activation was compared within-subjects following four randomly ordered experimental sessions of opioid-only (intravenous fentanyl 1 μg/kg), pain-only (cold-pressor), opioid + pain, and a resting condition. Setting University General Clinical Research Center. Participants Twenty-one (11 female) healthy controls. Interventions Following exposure to treatment (fentanyl administration and/or cold-pressor pain), blood samples for NF-kB analysis were obtained. Main outcome measures Intracellular levels of activated NF-κB, in unstimulated and stimulated peripheral blood mononuclear cells at 15 and 30 minutes. Results Neither pain nor opioid administration alone effected NF-κB levels in cell populations; however, the combination of treatments induced significant increases of NF-κB in stimulated peripheral blood mononuclear cell, lymphocytes, and monocytes. Conclusions The combination of acute pain with opioids, as occurs in clinical situations, activates a key transcription factor involved in proinflammatory responses. PMID:25901477

  9. Effect of Experimental Cutaneous Hand Pain on Corticospinal Excitability and Short Afferent Inhibition.

    PubMed

    Mercier, Catherine; Gagné, Martin; Reilly, Karen T; Bouyer, Laurent J

    2016-09-29

    Sensorimotor integration is altered in people with chronic pain. While there is substantial evidence that pain interferes with neural activity in primary sensory and motor cortices, much less is known about its impact on integrative sensorimotor processes. Here, the short latency afferent inhibition (SAI) paradigm was used to assess sensorimotor integration in the presence and absence of experimental cutaneous heat pain applied to the hand. Ulnar nerve stimulation was combined with transcranial magnetic stimulation to condition motor evoked potentials (MEPs) in the first dorsal interosseous muscle. Four interstimulus intervals (ISI) were tested, based on the latency of the N20 component of the afferent sensory volley (N20-5 ms, N20+2 ms, N20+4 ms, N20+10 ms). In the PAIN condition, MEPs were smaller compared to the NEUTRAL condition (p = 0.005), and were modulated as a function of the ISI (p = 0.012). Post-hoc planned comparisons revealed that MEPs at N20+2 and N20+4 were inhibited compared to unconditioned MEPs. However, the level of inhibition (SAI) was similar in the PAIN and NEUTRAL conditions. This suggests that the interplay between pain and sensorimotor integration is not mediated through direct and rapid pathways as assessed by SAI, but rather might involve higher-order integrative areas.

  10. Experimental orofacial pain and sensory deprivation lead to perceptual distortion of the face in healthy volunteers.

    PubMed

    Dagsdóttir, Lilja Kristín; Skyt, Ina; Vase, Lene; Baad-Hansen, Lene; Castrillon, Eduardo; Svensson, Peter

    2015-09-01

    Patients suffering from persistent orofacial pain may sporadically report that the painful area feels "swollen" or "differently," a phenomenon that may be conceptualized as a perceptual distortion because there are no clinical signs of swelling present. Our aim was to investigate whether standardized experimental pain and sensory deprivation of specific orofacial test sites would lead to changes in the size perception of these face areas. Twenty-four healthy participants received either 0.2 mL hypertonic saline (HS) or local anesthetics (LA) into six regions (buccal, mental, lingual, masseter muscle, infraorbital and auriculotemporal nerve regions). Participants estimated the perceived size changes in percentage (0 % = no change, -100 % = half the size or +100 % = double the size), and somatosensory function was checked with tactile stimuli. The pain intensity was rated on a 0-10 Verbal Numerical Rating Scale (VNRS), and sets of psychological questionnaires were completed. HS and LA were associated with significant self-reported perceptual distortions as indicated by consistent increases in perceived size of the adjacent face areas (P ≤ 0.050). Perceptual distortion was most pronounced in the buccal region, and the smallest increase was observed in the auriculotemporal region. HS was associated with moderate levels of pain VNRS = 7.3 ± 0.6. Weak correlations were found between HS-evoked perceptual distortion and level of dissociation in two regions (P < 0.050). Experimental pain and transient sensory deprivation evoked perceptual distortions in all face regions and overall demonstrated the importance of afferent inputs for the perception of the face. We propose that perceptual distortion may be an important phenomenon to consider in persistent orofacial pain conditions.

  11. Patients with chronic pain.

    PubMed

    Salama-Hanna, Joseph; Chen, Grace

    2013-11-01

    Preoperative evaluation of patients with chronic pain is important because it may lead to multidisciplinary preoperative treatment of patients' pain and a multimodal analgesia plan for effective pain control. Preoperative multidisciplinary management of chronic pain and comorbid conditions, such as depression, anxiety, deconditioning, and opioid tolerance, can improve patient satisfaction and surgical recovery. Multimodal analgesia using pharmacologic and nonpharmacologic strategies shifts the burden of analgesia away from simply increasing opioid dosing. In more complicated chronic pain patients, multidisciplinary treatment, including pain psychology, physical therapy, judicious medication management, and minimally invasive interventions by pain specialists, can improve patients' satisfaction and surgical outcome. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. A multimodal parallel architecture: A cognitive framework for multimodal interactions.

    PubMed

    Cohn, Neil

    2016-01-01

    Human communication is naturally multimodal, and substantial focus has examined the semantic correspondences in speech-gesture and text-image relationships. However, visual narratives, like those in comics, provide an interesting challenge to multimodal communication because the words and/or images can guide the overall meaning, and both modalities can appear in complicated "grammatical" sequences: sentences use a syntactic structure and sequential images use a narrative structure. These dual structures create complexity beyond those typically addressed by theories of multimodality where only a single form uses combinatorial structure, and also poses challenges for models of the linguistic system that focus on single modalities. This paper outlines a broad theoretical framework for multimodal interactions by expanding on Jackendoff's (2002) parallel architecture for language. Multimodal interactions are characterized in terms of their component cognitive structures: whether a particular modality (verbal, bodily, visual) is present, whether it uses a grammatical structure (syntax, narrative), and whether it "dominates" the semantics of the overall expression. Altogether, this approach integrates multimodal interactions into an existing framework of language and cognition, and characterizes interactions between varying complexity in the verbal, bodily, and graphic domains. The resulting theoretical model presents an expanded consideration of the boundaries of the "linguistic" system and its involvement in multimodal interactions, with a framework that can benefit research on corpus analyses, experimentation, and the educational benefits of multimodality. Copyright © 2015.

  13. Viewing Pictures of a Romantic Partner Reduces Experimental Pain: Involvement of Neural Reward Systems

    PubMed Central

    Younger, Jarred; Aron, Arthur; Parke, Sara; Chatterjee, Neil; Mackey, Sean

    2010-01-01

    The early stages of a new romantic relationship are characterized by intense feelings of euphoria, well-being, and preoccupation with the romantic partner. Neuroimaging research has linked those feelings to activation of reward systems in the human brain. The results of those studies may be relevant to pain management in humans, as basic animal research has shown that pharmacologic activation of reward systems can substantially reduce pain. Indeed, viewing pictures of a romantic partner was recently demonstrated to reduce experimental thermal pain. We hypothesized that pain relief evoked by viewing pictures of a romantic partner would be associated with neural activations in reward-processing centers. In this functional magnetic resonance imaging (fMRI) study, we examined fifteen individuals in the first nine months of a new, romantic relationship. Participants completed three tasks under periods of moderate and high thermal pain: 1) viewing pictures of their romantic partner, 2) viewing pictures of an equally attractive and familiar acquaintance, and 3) a word-association distraction task previously demonstrated to reduce pain. The partner and distraction tasks both significantly reduced self-reported pain, although only the partner task was associated with activation of reward systems. Greater analgesia while viewing pictures of a romantic partner was associated with increased activity in several reward-processing regions, including the caudate head, nucleus accumbens, lateral orbitofrontal cortex, amygdala, and dorsolateral prefrontal cortex – regions not associated with distraction-induced analgesia. The results suggest that the activation of neural reward systems via non-pharmacologic means can reduce the experience of pain. PMID:20967200

  14. Lack of effect of chronic dextromethorphan on experimental pain tolerance in methadone-maintained patients

    PubMed Central

    Compton, Peggy A.; Ling, Walter; Torrington, Matt A.

    2014-01-01

    Good evidence exists to suggest that individuals on opioid maintenance for the treatment of addiction (i.e. methadone) are less tolerant of experimental pain than are matched controls or ex-opioid addicts, a phenomenon theorized to reflect opioid-induced hyperalgesia (OIH). Agonist activity at the excitatory ionotropic N-methyl-D-aspartate (NMDA) receptor on dorsal horn neurons has been implicated in the development of both OIH and its putative expression at the clinical level—opioid tolerance. The aim of this study was to evaluate the potential utility of the NMDA-receptor antagonist, dextromethorphan (DEX), to reverse or treat OIH in methadone-maintenance (MM) patients. Utilizing a clinical trial design and double-blind conditions, changes in pain threshold and tolerance [cold pressor (CP) and electrical stimulation (ES)] following a 5-week trial of DEX (titrated to 480 mg/day) in comparison with placebo was evaluated in a well-characterized sample of MM patients. The sample (n = 40) was 53% male and ethnically diverse (53% Latino, 28% African American, 10% White, 9% other), with a mean age of 48.0 years (SD = 6.97). Based on t-test analyses, no difference was found between groups on CP pain threshold, CP pain tolerance, ES pain threshold or ES pain tolerance, both pre- and postmedication. Notably, DEX-related changes significantly differed by gender, with women tending to show diminished tolerance for pain with DEX therapy. These results support that chronic high-dose NMDA antagonism does not improve tolerance for pain in MM patients, although a gender effect on DEX response is suggested. PMID:18507735

  15. REPEATED EXPOSURE TO EXPERIMENTAL PAIN DIFFERENTIATES COMBAT TBI WITH AND WITHOUT PTSD.

    PubMed

    Strigo, Irina A; Spadoni, Andrea D; Inslicht, Sabra S; Simmons, Alan N

    2017-09-20

    Mild traumatic brain injury(mTBI) and posttraumatic stress disorder(PTSD) are highly comorbid conditions that often co-occur with chronic pain. We have shown that women with PTSD following intimate partner violence show attenuated brain response to repeated experimental pain that was related to symptoms of avoidance. The aim of this study was to extend our prior findings to males with combat trauma and to examine brain response to experimental pain in men with and without PTSD who sustained mTBI during combat. Seventy male Veterans performed an experimental pain paradigm during fMRI. Of the 70 total subjects, 46 self-reported a history of mTBI during combat(46/70). Of those with mTBI, 26 also met criteria for PTSD(26/46) .  As in our prior study, we examined change in brain activity to repeated heat pain with linear mixed effects modeling for group by administration interaction effects. We observed a significant group by administration interaction to repeated heat pain within insular, frontal and parietal cortices such that the control group showed increased activation over time, while mTBI groups(mTBI-only, mTBI+PTSD) showed decreased activation within bilateral anterior insulas(AI) between administrations. Importantly, change in the right AI response was inversely correlated with avoidance symptoms, but only in those with co-morbid mTBI+PTSD. Furthermore, in the comorbid group greater AI attenuation was associated with decreased connectivity with anterior cingulate(ACC). The current study provides further evidence that repeated exposure to brief painful stimuli results in attenuation of insula activation over time in traumatized individuals. Furthermore, in PTSD, AI shows greatest attenuation in those with the highest level of avoidance - a finding that was replicated across diverse samples.  Thus, this mechanism may be a generalized mechanism of maladaptive response to experimental pain in those with significant trauma.

  16. A method for studying jaw muscle activity during standardized jaw movements under experimental jaw muscle pain.

    PubMed

    Sae-Lee, Daraporn; Wanigaratne, Kamal; Whittle, Terry; Peck, Christopher C; Murray, Greg M

    2006-10-30

    This paper describes a method for studying superficial and deep jaw muscle activity during standardized jaw movements under experimental jaw muscle pain. In 22 healthy adults, pain was elicited in the right masseter muscle via tonic infusion of 4.5% hypertonic saline and which resulted in scores of 30-60 mm on a 100-mm visual analogue scale. Subjects performed tasks in five sessions in a repeated measures design, i.e., control 1, test 1 (during hypertonic or isotonic saline infusion), control 2 (without infusion), test 2 (during isotonic or hypertonic saline infusion), control 3 (without infusion). During each session, subjects performed maximal clenching and standardized jaw tasks, i.e., protrusion, lateral excursion, open/close, chewing. Mandibular movement was recorded with a 6-degree-of-freedom tracking system simultaneously with electromyographic (EMG) activity from the inferior head of the lateral pterygoid muscle with fine-wire electrodes (verified by computer tomography), and from posterior temporalis, the submandibular muscle group and bilateral masseter muscles with surface electrodes. EMG root mean square values were calculated at each 0.5 mm increment of mandibular incisor movement for all tasks under each experimental session. This establishes an experimental model for testing the effects of pain on jaw muscle activity where the jaw motor system is required to perform goal-directed tasks, and therefore should extend our understanding of the effects of pain on the jaw motor system.

  17. Dose-specific effects of transcutaneous electrical nerve stimulation (TENS) on experimental pain: a systematic review.

    PubMed

    Claydon, Leica S; Chesterton, Linda S; Barlas, Panos; Sim, Julius

    2011-09-01

    To determine the hypoalgesic effects of transcutaneous electrical nerve stimulation (TENS) parameter combinations on experimental models in healthy humans. Searches were performed using the electronic databases Ovid MEDLINE, CINAHL, AMED, and Web of Science (from inception to December 2009). Manual searches of journals and reference lists of retrieved trials were also performed. Randomized controlled trials (RCTs) were included in the review if they compared the hypoalgesic effect of TENS relative with placebo and control, using an experimental pain model in healthy human participants. Two reviewers independently selected the trials, assessed their methodologic quality and extracted data. Forty-three RCTs were eligible for inclusion. A best evidence synthesis revealed: Overall "conflicting" (inconsistent findings in multiple RCTs) evidence of TENS efficacy on experimental pain irrespective of TENS parameters used. Overall intense TENS has "moderate" evidence of efficacy (1 high-quality and 2 low-quality trials). Conventional TENS has overall conflicting evidence of efficacy, this is derived from "strong" evidence of efficacy (generally consistent findings in multiple high-quality RCTs) on pressure pain but strong evidence of inefficacy on other pain models. "Limited" evidence (positive findings from 1 RCT) of hypoalgesia exists for some novel parameters. Low-intensity, low-frequency, local TENS has strong evidence of inefficacy. Inappropriate TENS (using "barely perceptible" intensities) has moderate evidence of inefficacy. The level of hypoalgesic efficacy of TENS is clearly dependent on TENS parameter combination selection (defined in terms of intensity, frequency, and stimulation site) and experimental pain model. Future clinical RCTs may consider these TENS dose responses.

  18. Complex regional pain syndrome (CRPS) or continuous unilateral distal experimental pain stimulation in healthy subjects does not bias visual attention towards one hemifield.

    PubMed

    Filippopulos, Filipp M; Grafenstein, Jessica; Straube, Andreas; Eggert, Thomas

    2015-11-01

    In natural life pain automatically draws attention towards the painful body part suggesting that it interacts with different attentional mechanisms such as visual attention. Complex regional pain syndrome (CRPS) patients who typically report on chronic distally located pain of one extremity may suffer from so-called neglect-like symptoms, which have also been linked to attentional mechanisms. The purpose of the study was to further evaluate how continuous pain conditions influence visual attention. Saccade latencies were recorded in two experiments using a common visual attention paradigm whereby orientating saccades to cued or uncued lateral visual targets had to be performed. In the first experiment saccade latencies of healthy subjects were measured under two conditions: one in which continuous experimental pain stimulation was applied to the index finger to imitate a continuous pain situation, and one without pain stimulation. In the second experiment saccade latencies of patients suffering from CRPS were compared to controls. The results showed that neither the continuous experimental pain stimulation during the experiment nor the chronic pain in CRPS led to an unilateral increase of saccade latencies or to a unilateral increase of the cue effect on latency. The results show that unilateral, continuously applied pain stimuli or chronic pain have no or only very limited influence on visual attention. Differently from patients with visual neglect, patients with CRPS did not show strong side asymmetries of saccade latencies or of cue effects on saccade latencies. Thus, neglect-like clinical symptoms of CRPS patients do not involve the allocation of visual attention.

  19. Exostosis Bursata - Multimodality Imaging Approach.

    PubMed

    Ali, Asik Ali Mohamed; Sharma, Praveen; Rege, Rujuta; Seena, C R; Rajesh, Saveetha

    2016-09-01

    Osteochondromas or exostosis are common benign bone tumours, commonly arising from the metaphyseal region of long bones (femur, humerus, tibia). Osteochondroma of the scapula are rare and cause mechanical irritation leading to bursal formation. We hereby report a case of 30-year-old man who presented with painful chest wall swelling and its multimodality approach to establish the diagnosis.

  20. A Quantitative Review of Ethnic Group Differences in Experimental Pain Response: Do Biology, Psychology and Culture Matter?

    PubMed Central

    Riley, Joseph L.; Williams, Ameenah K.K.; Fillingim, Roger B.

    2012-01-01

    Objective Pain is a subjectively complex and universal experience. We examine research investigating ethnic group differences in experimental pain response, and factors contributing to group differences. Method We conducted a systematic literature review and analysis of studies using experimental pain stimuli to assess pain sensitivity across multiple ethnic groups. Our search covered the period from 1944-2011, and utilized the PUBMED bibliographic database; a reference source containing over 17 million citations. We calculated effect sizes, identified ethnic/racial group categories, pain stimuli and measures, and examined findings regarding biopsychosociocultural factors contributing to ethnic/racial group differences. Results We found 472 studies investigating ethnic group differences and pain. Twenty-six of these met our review inclusion criteria of investigating ethnic group differences in experimental pain. The majority of studies included comparisons between African Americans (AA) and non-Hispanic Whites (NHW). There were consistently moderate to large effect sizes for pain tolerance across multiple stimulus modalities; African Americans demonstrated lower pain tolerance. For pain threshold, findings were generally in the same direction, but effect sizes were small to moderate across ethnic groups. Limited data were available for suprathreshold pain ratings. A subset of studies comparing NHW and other ethnic groups showed a variable range of effect sizes for pain threshold and tolerance. Conclusion There are potentially important ethnic/racial group differences in experimental pain perception. Elucidating ethnic group differences, has translational merit for culturally-competent clinical care and for addressing and reducing pain treatment disparities among ethnically/racially diverse groups. PMID:22390201

  1. The effect of spinal manipulation on deep experimental muscle pain in healthy volunteers.

    PubMed

    O'Neill, Søren; Ødegaard-Olsen, Øystein; Søvde, Beate

    2015-01-01

    High-velocity low-amplitude (HVLA) spinal manipulation is commonly used in the treatment of spinal pain syndromes. The mechanisms by which HVLA-manipulation might reduce spinal pain are not well understood, but often assumed to relate to the reduction of biomechanical dysfunction. It is also possible however, that HVLA-manipulation involves a segmental or generalized inhibitory effect on nociception, irrespective of biomechanical function. In the current study it was investigated whether a local analgesic effect of HVLA-manipulation on deep muscle pain could be detected, in healthy individuals. Local, para-spinal muscle pain was induced by injection of 0.5 ml sterile, hyper-tonic saline on two separate occasions 1 week apart. Immediately following the injection, treatment was administered as either a) HVLA-manipulation or b) placebo treatment, in a randomized cross-over design. Both interventions were conducted by an experienced chiropractor with minimum 6 years of clinical experience. Participants and the researcher collecting data were blinded to the treatment allocation. Pain scores following saline injection were measured by computerized visual analogue pain scale (VAS) (0-100 VAS, 1 Hz) and summarized as a) Pain duration, b) Maximum VAS, c) Time to maximum VAS and d) Summarized VAS (area under the curve). Data analysis was performed as two-way analysis of variance with treatment allocation and session number as explanatory variables. Twenty-nine healthy adults (mean age 24.5 years) participated, 13 women and 16 men. Complete data was available for 28 participants. Analysis of variance revealed no statistically significant difference between active and placebo manipulation on any of the four pain measures. The current findings do not support the theory that HVLA-manipulation has a non-specific, reflex-mediated local or generalized analgesic effect on experimentally induced deep muscle pain. This in turn suggests, that any clinical analgesic effect of HVLA

  2. Caffeine does not attenuate experimentally induced ischemic pain in healthy subjects.

    PubMed

    Dellermalm, J; Segerdahl, M; Grass, S

    2009-11-01

    Caffeine is likely the most widely used psychoactive substance in the world. It is also an analgesic adjuvant and has individual analgesic properties. The latter effect has been attributed to adenosine receptor antagonism, but the site of action is unknown. The aim of this study was to investigate the analgesic properties of caffeine on experimentally induced ischemic pain and to attempt to elucidate whether the site of action is central or peripheral. Seventeen healthy subjects received intravenous (i.v.) regional and systemic infusions of caffeine at 10 mg/kg or placebo in a double-blind, crossover fashion to investigate the site of action for caffeine-induced analgesia. Subjects underwent a sub-maximum effort tourniquet test. Pain scores [visual analogue scale (VAS), 0-100] were assessed every minute up to a maximum of 45 min. The sum of pain scores (SPS, accumulation of VAS scores) was attenuated neither by systemic 2405 (+/-234) nor by i.v. regional caffeine 2427 (+/-190) as compared with placebo 2442 (+/-205), P=0.99 (mean+/-SEM). Time to maximal VAS score did not differ significantly between treatments, P=0.94. There was no correlation between caffeine concentration in plasma and time to maximal pain score, or between SPS and plasma concentration. Caffeine does not have an analgesic effect on ischemic pain, either by a peripheral or by a central site of action.

  3. Experimental muscle pain changes the spatial distribution of upper trapezius muscle activity during sustained contraction.

    PubMed

    Madeleine, Pascal; Leclerc, Fredéric; Arendt-Nielsen, Lars; Ravier, Philippe; Farina, Dario

    2006-11-01

    To investigate the effect of local excitation of nociceptive muscle afferents on the spatial distribution of muscle activity. Surface electromyographic (EMG) signals were recorded from the upper trapezius muscle of 10 healthy volunteers with a 5 x 13 electrode grid during 90-s isometric contractions before, during, 15 and 30 min after intramuscular injection of hypertonic (painful) or isotonic (non-painful) saline. From the multi-channel EMG recordings, two-dimensional maps of root mean square and mean power frequency were obtained. The centre of gravity of the root mean square map was used to quantify global changes in the spatial distribution of muscle activity. During sustained contractions, average root mean square increased, average mean frequency decreased and the centre of gravity moved cranially. During experimental muscle pain, compared to before injection, the average root mean square decreased and there was a caudal shift of the centre of gravity. Fifteen minutes after the painful injection the centre of gravity returned to its original position. Short-term dynamic reorganization of the spatial distribution of muscle activity occurred in response to nociceptive afferent input. The study furnishes an extension of the pain adaptation model indicating heterogeneous inhibition of muscle activity.

  4. Prices need no preferences: social trends determine decisions in experimental markets for pain relief.

    PubMed

    Vlaev, Ivo; Seymour, Ben; Chater, Nick; Winston, Joel S; Yoshida, Wako; Wright, Nicholas; Symmonds, Mkael; Dolan, Ray

    2014-01-01

    A standard view in health economics is that, although there is no market that determines the "prices" for health states, people can nonetheless associate health states with monetary values (or other scales, such as quality adjusted life year [QALYs] and disability adjusted life year [DALYs]). Such valuations can be used to shape health policy, and a major research challenge is to elicit such values from people; creating experimental "markets" for health states is a theoretically attractive way to address this. We explore the possibility that this framework may be fundamentally flawed-because there may not be any stable values to be revealed. Instead, perhaps people construct ad hoc values, influenced by contextual factors, such as the observed decisions of others. The participants bid to buy relief from equally painful electrical shocks to the leg and arm in an experimental health market based on an interactive second-price auction. Thirty subjects were randomly assigned to two experimental conditions where the bids by "others" were manipulated to follow increasing or decreasing price trends for one, but not the other, pain. After the auction, a preference test asked the participants to choose which pain they prefer to experience for a longer duration. Players remained indifferent between the two pain-types throughout the auction. However, their bids were differentially attracted toward what others bid for each pain, with overbidding during decreasing prices and underbidding during increasing prices. Health preferences are dissociated from market prices, which are strongly referenced to others' choices. This suggests that the price of health care in a free-market has the capacity to become critically detached from people's underlying preferences. 2014 APA, all rights reserved

  5. Within-team Patterns of Communication and Referral in Multimodal Treatment of Chronic Low Back Pain Patients by an Integrative Care Team

    PubMed Central

    O'Connor, Bonnie B.; Eisenberg, David M.; Buring, Julie E.; Liang, Catherine L.; Osypiuk, Kamila; Levy, Donald B.

    2015-01-01

    Background: Nonspecific chronic low back pain (CLBP) is a highly prevalent and costly public health problem with few treatment options that provide consistent and greater than modest benefits. Treatment of CLBP is shifting from unimodal to multimodal and multidisciplinary approaches, including biopsychosocially-based complementary and integrative care. Multidisciplinary approaches require unique levels of communication and coordination amongst clinicians; however, to date few studies have evaluated patterns of communication and decision making amongst clinicians collaborating in the care of challenging patients with CLBP. Methods: As part of an observational study evaluating the effectiveness and cost-effectiveness of an integrative, team-based care model for the treatment of CLBP, we used multiple qualitative research methods to characterize within-team cross-referral and communication amongst jointly-trained practitioners representing diverse biomedical and complementary disciplines. Patterns of communication and coordinated care are summarized for 3 cases of CLBP treated by multiple members (≥3) of an integrative medical team embedded within an academic hospital. Results: Patients were aged from 36 to 88 years with varied comorbidities. Qualitative content analysis revealed 5 emergent themes regarding integrative patient care and treatment decision in this clinic: (1) the fundamental importance of the clinic's formal teamwork training; (2) the critical communicative and collaborative function of regular team meetings; (3) the importance to patient care goals of having the varied disciplines practicing “under one roof”; (4) a universal commitment to understanding and treating patients as whole persons; and (5) a shared philosophy of helping patients to help themselves. These key themes are all interconnected and form the foundation of the clinic's culture. Conclusions: Our qualitative findings provide context for current trends in enhancing patient

  6. The impact of neurodynamic testing on the perception of experimentally induced muscle pain.

    PubMed

    Coppieters, Michel W; Kurz, Kimberly; Mortensen, Thor Einar; Richards, Nicola L; Skaret, Ingrid A; McLaughlin, Laurie M; Hodges, Paul W

    2005-02-01

    Neurodynamic tests such as the straight leg raising (SLR) and slump test are frequently used for assessment of mechanosensitivity of neural tissues. However, there is ongoing debate in the literature regarding the contributions of neural and non-neural tissues to the elicited symptoms because many structures are affected by these tests. Sensitizing manoeuvres are limb or spinal movements added to neurodynamic tests, which aim to identify the origin of the symptoms by preferentially loading or unloading neural structures. A prerequisite for the use of sensitizing manoeuvres to identify neural involvement is that the addition of sensitizing manoeuvres has no impact on pain perception when the origin of the pain is non-neural. In this study, experimental muscle pain was induced by injection of hypertonic saline in tibialis anterior or soleus in 25 asymptomatic, naive volunteers. A first experiment investigated the impact of hip adduction, abduction, medial and lateral rotation in the SLR position. In a second experiment, the different stages of the slump test were examined. The intensity and area of experimentally induced muscle pain did not increase when sensitizing manoeuvres were added to the SLR or throughout the successive stages of the slump test. The findings of this study lend support to the validity of the use of sensitizing manoeuvres during neurodynamic testing.

  7. Evaluation of pain in rats through facial expression following experimental tooth movement.

    PubMed

    Liao, Lina; Long, Hu; Zhang, Li; Chen, Helin; Zhou, Yang; Ye, Niansong; Lai, Wenli

    2014-04-01

    This study was carried out to evaluate pain in rats by monitoring their facial expressions following experimental tooth movement. Male Sprague-Dawley rats were divided into the following five groups based on the magnitude of orthodontic force applied and administration of analgesics: control; 20 g; 40 g; 80 g; and morphine + 40 g. Closed-coil springs were used to mimic orthodontic forces. The facial expressions of each rat were videotaped, and the resulting rat grimace scale (RGS) coding was employed for pain quantification. The RGS score increased on day 1 but showed no significant change thereafter in the control and 20-g groups. In the 40- and 80-g groups, the RGS scores increased on day 1, peaked on day 3, and started to decrease on day 5. At 14 d, the RGS scores were similar in control and 20-, 40-, and 80-g groups and did not return to baseline. The RGS scores in the morphine + 40-g group were significantly lower than those in the control group. Our results reveal that coding of facial expression is a valid method for evaluation of pain in rats following experimental tooth movement. Inactivated springs (no force) still cause discomfort and result in an increase in the RGS. The threshold force magnitude required to evoke orthodontic pain in rats is between 20 and 40 g. © 2014 Eur J Oral Sci.

  8. Multimodality imaging techniques.

    PubMed

    Martí-Bonmatí, Luis; Sopena, Ramón; Bartumeus, Paula; Sopena, Pablo

    2010-01-01

    In multimodality imaging, the need to combine morphofunctional information can be approached by either acquiring images at different times (asynchronous), and fused them through digital image manipulation techniques or simultaneously acquiring images (synchronous) and merging them automatically. The asynchronous post-processing solution presents various constraints, mainly conditioned by the different positioning of the patient in the two scans acquired at different times in separated machines. The best solution to achieve consistency in time and space is obtained by the synchronous image acquisition. There are many multimodal technologies in molecular imaging. In this review we will focus on those multimodality image techniques more commonly used in the field of diagnostic imaging (SPECT-CT, PET-CT) and new developments (as PET-MR). The technological innovations and development of new tracers and smart probes are the main key points that will condition multimodality image and diagnostic imaging professionals' future. Although SPECT-CT and PET-CT are standard in most clinical scenarios, MR imaging has some advantages, providing excellent soft-tissue contrast and multidimensional functional, structural and morphological information. The next frontier is to develop efficient detectors and electronics systems capable of detecting two modality signals at the same time. Not only PET-MR but also MR-US or optic-PET will be introduced in clinical scenarios. Even more, MR diffusion-weighted, pharmacokinetic imaging, spectroscopy or functional BOLD imaging will merge with PET tracers to further increase molecular imaging as a relevant medical discipline. Multimodality imaging techniques will play a leading role in relevant clinical applications. The development of new diagnostic imaging research areas, mainly in the field of oncology, cardiology and neuropsychiatry, will impact the way medicine is performed today. Both clinical and experimental multimodality studies, in

  9. A Learning Algorithm for Multimodal Grammar Inference.

    PubMed

    D'Ulizia, A; Ferri, F; Grifoni, P

    2011-12-01

    The high costs of development and maintenance of multimodal grammars in integrating and understanding input in multimodal interfaces lead to the investigation of novel algorithmic solutions in automating grammar generation and in updating processes. Many algorithms for context-free grammar inference have been developed in the natural language processing literature. An extension of these algorithms toward the inference of multimodal grammars is necessary for multimodal input processing. In this paper, we propose a novel grammar inference mechanism that allows us to learn a multimodal grammar from its positive samples of multimodal sentences. The algorithm first generates the multimodal grammar that is able to parse the positive samples of sentences and, afterward, makes use of two learning operators and the minimum description length metrics in improving the grammar description and in avoiding the over-generalization problem. The experimental results highlight the acceptable performances of the algorithm proposed in this paper since it has a very high probability of parsing valid sentences.

  10. Experimental tooth clenching. A model for studying mechanisms of muscle pain.

    PubMed

    Dawson, Andreas

    2013-01-01

    The overall goal of this thesis was to broaden knowledge of pain mechanisms in myofascial temporomandibular disorders (M-TMD). The specific aims were to: Develop a quality assessment tool for experimental bruxism studies (study I). Investigate proprioceptive allodynia after experimental tooth clenching exercises (study II). Evaluate the release of serotonin (5-HT), glutamate, pyruvate, and lactate in healthy subjects (study III) and in patients with M-TMD (study IV), after experimental tooth clenching exercises. In (I), tool development comprised 5 steps: (i) preliminary decisions, (ii) item generation, (iii) face-validity assessment, (iv) reliability and discriminative validity testing, and (v) instrument refinement. After preliminary decisions and a literature review, a list of 52 items to be considered for inclusion in the tool was generated. Eleven experts were invited to participate on the Delphi panel, of which 10 agreed. After four Delphi rounds, 8 items remained and were included in the Quality Assessment Tool for Experimental Bruxism Studies (Qu-ATEBS). Inter-observer reliability was acceptable (k = 0.77), and discriminative validity high (phi coefficient 0.79; P < 0.01). During refinement, 1 item was removed; the final tool comprised 7 items. In (II), 16 healthy females participated in three 60-min sessions, each with 24- and 48-h follow-ups. Participants were randomly assigned to a repetitive experimental tooth clenching task with a clenching level of 10%, 20%, or 40% of maximal voluntary clenching force (MVCF). Pain intensity, fatigue, perceived intensity of vibration (PIV), perceived discomfort (PD), and pressure pain threshold (PPT) were measured throughout. A significant increase in pain intensity and fatigue but not in PD was observed over time. A significant increase in PIV was only observed at 40 min, and PPT decreased significantly over time at 50 and 60 min compared to baseline. In (III), 30 healthy subjects (16 females, and 14 males

  11. The effect of cognitive bias modification for interpretation on avoidance of pain during an acute experimental pain task.

    PubMed

    Jones, Emma Blaisdale; Sharpe, Louise

    2014-08-01

    Research confirms that patients with chronic pain show a tendency to interpret ambiguous stimuli as pain related. However, whether modifying these interpretive pain biases impacts pain outcomes is unknown. This study aimed to demonstrate that interpretation biases towards pain can be modified, and that changing these biases influences pain outcomes in the cold pressor task. One hundred and six undergraduate students were randomly allocated to receive either threatening or reassuring information regarding the cold pressor. They also were randomly allocated to 1 of 2 conditions in the Ambiguous Scenarios Task, in which they were trained to have either a threatening interpretation of pain (pain bias condition) or a nonthreatening interpretation of pain (no pain bias condition). Therefore, the study had a 2 (threat/reassuring)×2 (pain bias/no pain bias) design. Analyses showed that a bias was induced contingent on condition, and that the threat manipulation was effective. Participants in the pain bias condition hesitated more before doing the cold pressor task than those in the no pain bias condition, as did those in the threat compared with the reassurance condition. The major finding was that interpretive bias mediated the relationship between bias condition and hesitance time, supporting the causal role of interpretive biases for avoidance behaviors in current chronic pain models. No differences were found on other pain outcomes regarding bias or threat, and the efficacy of the bias modification was not impacted by different levels of threat. These results suggest that cognitive bias modification should be further explored as a potential intervention in pain.

  12. Pain.

    PubMed

    Melzack, Ronald; Katz, Joel

    2013-01-01

    Pain has many valuable functions. It often signals injury or disease, generates a wide range of adaptive behaviors, and promotes healing through rest. Despite these beneficial aspects of pain, there are negative features that challenge our understanding of the puzzle of pain, including persistent phantom limb pain after amputation or total spinal cord transection. Pain is a personal, subjective experience influenced by cultural learning, the meaning of the situation, attention, and other psychological variables. Pain processes do not begin with the stimulation of receptors. Rather, injury or disease produces neural signals that enter an active nervous system that (in the adult organism) is the substrate of past experience, culture, and a host of other environmental and personal factors. These brain processes actively participate in the selection, abstraction, and synthesis of information from the total sensory input. Pain is not simply the end product of a linear sensory transmission system; it is a dynamic process that involves continuous interactions among complex ascending and descending systems. The neuromatrix theory guides us away from the Cartesian concept of pain as a sensation produced by injury, inflammation, or other tissue pathology and toward the concept of pain as a multidimensional experience produced by multiple influences. These influences range from the existing synaptic architecture of the neuromatrix-which is determined by genetic and sensory factors-to influences from within the body and from other areas in the brain. Genetic influences on synaptic architecture may determine-or predispose toward-the development of chronic pain syndromes. WIREs Cogn Sci 2013, 4:1-15. doi: 10.1002/wcs.1201 For further resources related to this article, please visit the WIREs website.

  13. Effectiveness of a Multimodal Community Intervention Program to Prevent Suicide and Suicide Attempts: A Quasi-Experimental Study

    PubMed Central

    Ono, Yutaka; Sakai, Akio; Otsuka, Kotaro; Uda, Hidenori; Oyama, Hirofumi; Ishizuka, Naoki; Awata, Shuichi; Ishida, Yasushi; Iwasa, Hiroto; Kamei, Yuichi; Motohashi, Yutaka; Nakamura, Jun; Nishi, Nobuyuki; Watanabe, Naoki; Yotsumoto, Toshihiko; Nakagawa, Atsuo; Suzuki, Yuriko; Tajima, Miyuki; Tanaka, Eriko; Sakai, Hironori; Yonemoto, Naohiro

    2013-01-01

    Background Multilevel and multimodal interventions have been suggested for suicide prevention. However, few studies have reported the outcomes of such interventions for suicidal behaviours. Methods We examined the effectiveness of a community-based multimodal intervention for suicide prevention in rural areas with high suicide rates, compared with a parallel prevention-as-usual control group, covering a total of 631,133 persons. The effectiveness was also examined in highly populated areas near metropolitan cities (1,319,972 persons). The intervention started in July 2006, and continued for 3.5 years. The primary outcome was the incidence of composite outcome, consisting of completed suicides and suicide attempts requiring admission to an emergency ward for critical care. We compared the rate ratios (RRs) of the outcomes adjusted by sex, age group, region, period and interaction terms. Analyses were performed on an intention-to-treat basis and stratified by sex and age groups. Findings In the rural areas, the overall median adherence of the intervention was significantly higher. The RR of the composite outcome in the intervention group decreased 7% compared with that of the control group. Subgroup analyses demonstrated heterogeneous effects among subpopulations: the RR of the composite outcome in the intervention group was significantly lower in males (RR = 0.77, 95% CI 0.59–0.998, p = 0.0485) and the RR of suicide attempts was significantly lower in males (RR = 0.39, 95% CI 0.22–0.68, p = 0.001) and the elderly (RR = 0.35, 95% CI 0.17–0.71, p = 0.004). The intervention had no effect on the RR of the composite outcome in the highly populated areas. Interpretation Our findings suggest that this community-based multimodal intervention for suicide prevention could be implemented in rural areas, but not in highly populated areas. The effectiveness of the intervention was shown for males and for the elderly in rural areas. Trial

  14. Multimodal Analgesia in the Hip Fracture Patient.

    PubMed

    Fabi, David W

    2016-05-01

    Hip fracture is one of the most common injuries among the elderly and, because the population is aging, it is expected to remain a major clinical challenge and public health problem for the foreseeable future. The clinical importance of early mobilization and prompt participation in physical therapy after hip fracture surgery is now widely recognized. Because postoperative pain can impair mobility and delay physical therapy, much attention is now being paid to finding more effective ways of controlling pain after hip fracture. Oversedation with opioid drugs inhibits communication between the patient and the health care team, can delay ambulation and rehabilitation therapy, and may increase the probability of the patient requiring a skilled nursing facility, which adds further cost to the overall health care system. Multiple pain pathways contribute to the perception of postoperative pain, and although opioids are highly effective in blocking nociceptive pain through inhibition of the mu receptors, they do not block other pain pathways. Multimodal analgesia involves the use of several anesthetic and analgesic modalities that are strategically combined to block pain perception at different sites in the peripheral and central nervous systems. This balanced, multifaceted approach provides more effective control of postoperative pain than opioid drugs alone, allows lower doses of opioids to be used as part of the multimodal regimen (thereby reducing the risk of opioid-related adverse events and complications), and may facilitate more rapid recovery and improve certain outcome measures related to recovery time. One prospective randomized study evaluating the clinical value of multimodal pain management in elderly patients undergoing bipolar hip hemiarthroplasty found that a multimodal regimen, including preemptive pain medication and intraoperative periarticular injections, reduced pain on postoperative days 1 and 4, and reduced overall opioid use. This article describes

  15. CONTROL OF LASER RADIATION PARAMETERS: Gerchberg—Saxton algorithm: experimental realisation and modification for the problem of formation of multimode laser beams

    NASA Astrophysics Data System (ADS)

    Il'ina, I. V.; Cherezova, T. Yu; Kudryashov, A. V.

    2009-06-01

    An original method is proposed to calculate the formation of specified far-field intensity distributions by a bimorph mirror in the case of initial transverse-multimode beams. The method is based on the Gerchberg—Saxton algorithm with replacement of the phase function in the plane of the control element by a function that takes into account both the intensity and phase distributions of each mode. The numerical results on the formation of a beam with the third-order super-Gaussian intensity distribution from beams composed of two or four lowest transverse modes are discussed. The experimental results on using the conventional Gerchberg—Saxton algorithm to form a desired intensity distribution from single-mode laser beams using a liquid-crystal modulator are presented.

  16. Endogenous Opioid Antagonism in Physiological Experimental Pain Models: A Systematic Review

    PubMed Central

    Werner, Mads U.; Pereira, Manuel P.; Andersen, Lars Peter H.; Dahl, Jørgen B.

    2015-01-01

    Opioid antagonists are pharmacological tools applied as an indirect measure to detect activation of the endogenous opioid system (EOS) in experimental pain models. The objective of this systematic review was to examine the effect of mu-opioid-receptor (MOR) antagonists in placebo-controlled, double-blind studies using ʻinhibitoryʼ or ʻsensitizingʼ, physiological test paradigms in healthy human subjects. The databases PubMed and Embase were searched according to predefined criteria. Out of a total of 2,142 records, 63 studies (1,477 subjects [male/female ratio = 1.5]) were considered relevant. Twenty-five studies utilized ʻinhibitoryʼ test paradigms (ITP) and 38 studies utilized ʻsensitizingʼ test paradigms (STP). The ITP-studies were characterized as conditioning modulation models (22 studies) and repetitive transcranial magnetic stimulation models (rTMS; 3 studies), and, the STP-studies as secondary hyperalgesia models (6 studies), ʻpainʼ models (25 studies), summation models (2 studies), nociceptive reflex models (3 studies) and miscellaneous models (2 studies). A consistent reversal of analgesia by a MOR-antagonist was demonstrated in 10 of the 25 ITP-studies, including stress-induced analgesia and rTMS. In the remaining 14 conditioning modulation studies either absence of effects or ambiguous effects by MOR-antagonists, were observed. In the STP-studies, no effect of the opioid-blockade could be demonstrated in 5 out of 6 secondary hyperalgesia studies. The direction of MOR-antagonist dependent effects upon pain ratings, threshold assessments and somatosensory evoked potentials (SSEP), did not appear consistent in 28 out of 32 ʻpainʼ model studies. In conclusion, only in 2 experimental human pain models, i.e., stress-induced analgesia and rTMS, administration of MOR-antagonist demonstrated a consistent effect, presumably mediated by an EOS-dependent mechanisms of analgesia and hyperalgesia. PMID:26029906

  17. Pain in experimental autoimmune encephalitis: a comparative study between different mouse models

    PubMed Central

    2012-01-01

    Background Pain can be one of the most severe symptoms associated with multiple sclerosis (MS) and develops with varying levels and time courses. MS-related pain is difficult to treat, since very little is known about the mechanisms underlying its development. Animal models of experimental autoimmune encephalomyelitis (EAE) mimic many aspects of MS and are well-suited to study underlying pathophysiological mechanisms. Yet, to date very little is known about the sensory abnormalities in different EAE models. We therefore aimed to thoroughly characterize pain behavior of the hindpaw in SJL and C57BL/6 mice immunized with PLP139-151 peptide or MOG35-55 peptide respectively. Moreover, we studied the activity of pain-related molecules and plasticity-related genes in the spinal cord and investigated functional changes in the peripheral nerves using electrophysiology. Methods We analyzed thermal and mechanical sensitivity of the hindpaw in both EAE models during the whole disease course. Qualitative and quantitative immunohistochemical analysis of pain-related molecules and plasticity-related genes was performed on spinal cord sections at different timepoints during the disease course. Moreover, we investigated functional changes in the peripheral nerves using electrophysiology. Results Mice in both EAE models developed thermal hyperalgesia during the chronic phase of the disease. However, whereas SJL mice developed marked mechanical allodynia over the chronic phase of the disease, C57BL/6 mice developed only minor mechanical allodynia over the onset and peak phase of the disease. Interestingly, the magnitude of glial changes in the spinal cord was stronger in SJL mice than in C57BL/6 mice and their time course matched the temporal profile of mechanical hypersensitivity. Conclusions Diverse EAE models bearing genetic, clinical and histopathological heterogeneity, show different profiles of sensory and pathological changes and thereby enable studying the mechanistic basis

  18. Sacroiliac joint pain: Prospective, randomised, experimental and comparative study of thermal radiofrequency with sacroiliac joint block.

    PubMed

    Cánovas Martínez, L; Orduña Valls, J; Paramés Mosquera, E; Lamelas Rodríguez, L; Rojas Gil, S; Domínguez García, M

    2016-05-01

    To compare the analgesic effects between the blockade and bipolar thermal radiofrequency in the treatment of sacroiliac joint pain. Prospective, randomised and experimental study conducted on 60 patients selected in the two hospitals over a period of nine months, who had intense sacroiliac joint pain (Visual Analogue Scale [VAS]>6) that lasted more than 3 months. Patients were randomised into three groups (n=20): Group A (two intra-articular sacroiliac injections of local anaesthetic/corticosteroid guided by ultrasound in 7 days). Group B: conventional bipolar radiofrequency "palisade". Target points were the lateral branch nerves of S1, S2, and S3, distance needles 1cm. Group C: modified bipolar radiofrequency "palisade" (needle distance >1cm). Patients were evaluated at one month, three months, and one year. Demographic data, VAS reduction, and side effects of the techniques were assessed. One month after the treatment, pain reduction was >50% in the three groups P<.001. Three and 12 months after the technique, the patients of the group A did not have a significant reduction in pain. At 3 months, almost 50% patients of the group B referred to improvement of the pain (P=.03), and <25% at 12 months, and those results were statistically significant (P=.01) compared to the baseline. Group C showed an improvement of 50% at 3 and 12 months (P<.001). All patients completed the study. Bipolar radiofrequency "palisade", especially when the distance between the needles was increased, was more effective and lasted longer, compared to join block and steroids, in relieving pain sacroiliac joint. Copyright © 2015 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  19. Length of perineal pain relief after ice pack application: A quasi-experimental study.

    PubMed

    de Souza Bosco Paiva, Caroline; Junqueira Vasconcellos de Oliveira, Sonia Maria; Amorim Francisco, Adriana; da Silva, Renata Luana; de Paula Batista Mendes, Edilaine; Steen, Mary

    2016-04-01

    Ice pack is effective for alleviating postpartum perineal pain in primiparous women while multiparous women's levels of perineal pain appear to be poorly explored. Ice pack is a low-cost non-invasive localised treatment that can be used with no impact on breastfeeding. However, how long perineal analgesia persists after applying an ice pack is still unknown. To evaluate if perineal analgesia is maintained up to 2h after applying an ice pack to the perineum for 20min. A quasi-experimental study, using a pre and post-test design, was undertaken with a sample size of 50 multiparous women in Brazil. Data was collected by structured interview. The intervention involved a single application of an ice pack applied for 20min to the perineal area of women who reported perineal pain ≥3 by use of a numeric rating scale (0-10), with intact perineum, 1st or 2nd degree lacerations or episiotomy, between 6 and 24h after spontaneous vaginal birth. Perineal pain was evaluated at three points of time: before, immediately after and 2h after applying an ice pack. Immediately after applying an ice pack to the perineal area, there was a significant reduction in the severity of perineal pain reported (5.4 vs. 1.0, p<0.0005), which continued for 1h 35min up to 2h after the local application. Ice pack application for 20min is effective for alleviating postpartum perineal pain and continues to be effective between 1h 35min for up to 2h. Copyright © 2015 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  20. Central Pain Processing in Early-Stage Parkinson's Disease: A Laser Pain fMRI Study

    PubMed Central

    Petschow, Christine; Scheef, Lukas; Paus, Sebastian; Zimmermann, Nadine; Schild, Hans H.; Klockgether, Thomas; Boecker, Henning

    2016-01-01

    Background & Objective Pain is a common non-motor symptom in Parkinson’s disease. As dopaminergic dysfunction is suggested to affect intrinsic nociceptive processing, this study was designed to characterize laser-induced pain processing in early-stage Parkinson’s disease patients in the dopaminergic OFF state, using a multimodal experimental approach at behavioral, autonomic, imaging levels. Methods 13 right-handed early-stage Parkinson’s disease patients without cognitive or sensory impairment were investigated OFF medication, along with 13 age-matched healthy control subjects. Measurements included warmth perception thresholds, heat pain thresholds, and central pain processing with event-related functional magnetic resonance imaging (erfMRI) during laser-induced pain stimulation at lower (E = 440 mJ) and higher (E = 640 mJ) target energies. Additionally, electrodermal activity was characterized during delivery of 60 randomized pain stimuli ranging from 440 mJ to 640 mJ, along with evaluation of subjective pain ratings on a visual analogue scale. Results No significant differences in warmth perception thresholds, heat pain thresholds, electrodermal activity and subjective pain ratings were found between Parkinson’s disease patients and controls, and erfMRI revealed a generally comparable activation pattern induced by laser-pain stimuli in brain areas belonging to the central pain matrix. However, relatively reduced deactivation was found in Parkinson’s disease patients in posterior regions of the default mode network, notably the precuneus and the posterior cingulate cortex. Conclusion Our data during pain processing extend previous findings suggesting default mode network dysfunction in Parkinson’s disease. On the other hand, they argue against a genuine pain-specific processing abnormality in early-stage Parkinson’s disease. Future studies are now required using similar multimodal experimental designs to examine pain processing in more advanced

  1. Central Pain Processing in Early-Stage Parkinson's Disease: A Laser Pain fMRI Study.

    PubMed

    Petschow, Christine; Scheef, Lukas; Paus, Sebastian; Zimmermann, Nadine; Schild, Hans H; Klockgether, Thomas; Boecker, Henning

    2016-01-01

    Pain is a common non-motor symptom in Parkinson's disease. As dopaminergic dysfunction is suggested to affect intrinsic nociceptive processing, this study was designed to characterize laser-induced pain processing in early-stage Parkinson's disease patients in the dopaminergic OFF state, using a multimodal experimental approach at behavioral, autonomic, imaging levels. 13 right-handed early-stage Parkinson's disease patients without cognitive or sensory impairment were investigated OFF medication, along with 13 age-matched healthy control subjects. Measurements included warmth perception thresholds, heat pain thresholds, and central pain processing with event-related functional magnetic resonance imaging (erfMRI) during laser-induced pain stimulation at lower (E = 440 mJ) and higher (E = 640 mJ) target energies. Additionally, electrodermal activity was characterized during delivery of 60 randomized pain stimuli ranging from 440 mJ to 640 mJ, along with evaluation of subjective pain ratings on a visual analogue scale. No significant differences in warmth perception thresholds, heat pain thresholds, electrodermal activity and subjective pain ratings were found between Parkinson's disease patients and controls, and erfMRI revealed a generally comparable activation pattern induced by laser-pain stimuli in brain areas belonging to the central pain matrix. However, relatively reduced deactivation was found in Parkinson's disease patients in posterior regions of the default mode network, notably the precuneus and the posterior cingulate cortex. Our data during pain processing extend previous findings suggesting default mode network dysfunction in Parkinson's disease. On the other hand, they argue against a genuine pain-specific processing abnormality in early-stage Parkinson's disease. Future studies are now required using similar multimodal experimental designs to examine pain processing in more advanced stages of Parkinson's disease.

  2. Manipulating the Placebo Response in Experimental Pain by Altering Doctor’s Performance Style

    PubMed Central

    Czerniak, Efrat; Biegon, Anat; Ziv, Amitai; Karnieli-Miller, Orit; Weiser, Mark; Alon, Uri; Citron, Atay

    2016-01-01

    Background: Performance is paramount in traditional healing rituals. From a Western perspective, such performative behavior can be understood principally as inducing patients’ faith in the performer’s supernatural healing powers and effecting positive changes through the same mechanisms attributed to the placebo response, which is defined as improvement of clinical outcome in individuals receiving inactive treatment. Here we examined the possibility of using theatrical performance tools, including stage directions and scripting, to reproducibly manipulate the style and content of a simulated doctor–patient encounter and influence the placebo response in experimental pain. Methods: A total of 122 healthy volunteers (18–45 years, 76 men) exposed to experimental pain (the cold pressor test) were assessed for pain threshold and tolerance before and after receiving a placebo cream from a “doctor” impersonated by a trained actor. The actor alternated between two distinct scripts and stage directions, i.e., performance styles created by a theater director/playwright, one emulating a standard doctor–patient encounter (scenario A) and the other emphasizing attentiveness and strong suggestion, elements also present in ritual healing (scenario B). The placebo response size was calculated as the %difference in pain threshold and tolerance after exposure relative to baseline. In addition, subjects demonstrating a ≥30% increase in pain threshold or tolerance relative to baseline were defined as responders. Each encounter was videotaped in its entirety. Results: Inspection of the videotapes confirmed the reproducibility and consistency of the distinct scenarios enacted by the “doctor”-performer. Furthermore, scenario B resulted in a significant increase in pain threshold relative to scenario A. Interestingly, this increase derived from the placebo responder subgroup; as shown by two-way analysis of variance (performance style, F = 4.30; p = 0.040; η2 = 0

  3. Bilateral experimental muscle pain changes electromyographic activity of human jaw-closing muscles during mastication.

    PubMed

    Svensson, P; Houe, L; Arendt-Nielsen, L

    1997-08-01

    The effects of bilateral experimental muscle pain on human masticatory patterns were studied. Jaw movements and electromyographic (EMG) recordings of the jaw-closing muscles were divided into multiple single masticatory cycles and analyzed on a cycle-by-cycle basis. In ten men simultaneous bilateral injections of hypertonic saline (5%) into the masseter muscles caused strong pain (mean+/-SE: 7.5+/-0.4 on a 0-10 scale), significantly reduced EMG activity of jaw-closing muscles in the agonist phase, and significantly increased EMG activity in the antagonist phase. Nine of the subjects reported a sensation of less intense mastication during pain. Injections of isotonic saline (0.9%) did not cause pain or significant changes in masticatory patterns. The influence of higher brain centers on conscious human mastication can not be discarded but the observed phase-dependent modulation could be controlled by local neural circuits and/or a central pattern generator in the brain stem which are capable of integrating bilateral nociceptive afferent activity.

  4. Antero-posterior activity changes in the superficial masseter muscle after exposure to experimental pain.

    PubMed

    Türp, Jens C; Schindler, Hans J; Pritsch, Maria; Rong, Qiguo

    2002-04-01

    The aim of this randomized, controlled, double-blind study was to examine how the activation pattern of the masseter muscle changes during natural function when experimental pain is induced in a discrete anterior area of the muscle. In 20 subjects, three bipolar surface electrodes and three intramuscular fine-wire electrodes (antero-posterior mapping) were simultaneously attached above and in the right masseter muscle to record the electromyographic (EMG) activity during unilateral chewing before and after infusion of a 0.9% isotonic and 5% hypertonic saline bolus in the anterior area of the muscle. The activity of the contralateral masseter muscle was registered by surface electrodes. In addition, the development of pain intensity was quantitatively measured with a numerical rating scale (NRS). While both saline concentrations caused pain, the hypertonic solution evoked stronger pain. The experiments also provided evidence of a significant although differential activity reduction of the ipsilateral masseter muscle in the antero-posterior direction. The activity reduction decreased with increasing distance from the location of the infusion. The results support the idea that the strategy of differential activation protects the injured muscle while simultaneously maintaining optimal function.

  5. Indirect acquisition of pain-related fear: an experimental study of observational learning using coloured cold metal bars.

    PubMed

    Helsen, Kim; Vlaeyen, Johan W S; Goubert, Liesbet

    2015-01-01

    Previous research has demonstrated that pain-related fear can be acquired through observation of another's pain behaviour during an encounter with a painful stimulus. The results of two experimental studies were presented, each with a different pain stimulus, of which the aim was to investigate the effect of observational learning on pain expectancies, avoidance behaviour, and physiological responding. Additionally, the study investigated whether certain individuals are at heightened risk to develop pain-related fear through observation. Finally, changes in pain-related fear and pain intensity after exposure to the feared stimulus were examined. During observational acquisition, healthy female participants watched a video showing coloured cold metal bars being placed against the neck of several models. In a differential fear conditioning paradigm, one colour was paired with painful facial expressions, and another colour was paired with neutral facial expressions of the video models. During exposure, both metal bars with equal temperatures (-25° or +8° Celsius) were placed repeatedly against participants' own neck. Results showed that pain-related beliefs can be acquired by observing pain in others, but do not necessarily cause behavioural changes. Additionally, dispositional empathy might play a role in the acquisition of these beliefs. Furthermore, skin conductance responses were higher when exposed to the pain-associated bar, but only in one of two experiments. Differential pain-related beliefs rapidly disappeared after first-hand exposure to the stimuli. This study enhances our understanding of pain-related fear acquisition and subsequent exposure to the feared stimulus, providing leads for pain prevention and management strategies.

  6. Indirect Acquisition of Pain-Related Fear: An Experimental Study of Observational Learning Using Coloured Cold Metal Bars

    PubMed Central

    Helsen, Kim; Vlaeyen, Johan W. S.; Goubert, Liesbet

    2015-01-01

    Background Previous research has demonstrated that pain-related fear can be acquired through observation of another’s pain behaviour during an encounter with a painful stimulus. The results of two experimental studies were presented, each with a different pain stimulus, of which the aim was to investigate the effect of observational learning on pain expectancies, avoidance behaviour, and physiological responding. Additionally, the study investigated whether certain individuals are at heightened risk to develop pain-related fear through observation. Finally, changes in pain-related fear and pain intensity after exposure to the feared stimulus were examined. Methods During observational acquisition, healthy female participants watched a video showing coloured cold metal bars being placed against the neck of several models. In a differential fear conditioning paradigm, one colour was paired with painful facial expressions, and another colour was paired with neutral facial expressions of the video models. During exposure, both metal bars with equal temperatures (-25° or +8° Celsius) were placed repeatedly against participants’ own neck. Results Results showed that pain-related beliefs can be acquired by observing pain in others, but do not necessarily cause behavioural changes. Additionally, dispositional empathy might play a role in the acquisition of these beliefs. Furthermore, skin conductance responses were higher when exposed to the pain-associated bar, but only in one of two experiments. Differential pain-related beliefs rapidly disappeared after first-hand exposure to the stimuli. Conclusions This study enhances our understanding of pain-related fear acquisition and subsequent exposure to the feared stimulus, providing leads for pain prevention and management strategies. PMID:25806969

  7. Rat experimental model of myocardial ischemia/reperfusion injury: an ethical approach to set up the analgesic management of acute post-surgical pain.

    PubMed

    Ciuffreda, Maria Chiara; Tolva, Valerio; Casana, Renato; Gnecchi, Massimiliano; Vanoli, Emilio; Spazzolini, Carla; Roughan, John; Calvillo, Laura

    2014-01-01

    During the past 30 years, myocardial ischemia/reperfusion injury in rodents became one of the most commonly used model in cardiovascular research. Appropriate pain-prevention appears critical since it may influence the outcome and the results obtained with this model. However, there are no proper guidelines for pain management in rats undergoing thoracic surgery. Accordingly, we evaluated three analgesic regimens in cardiac ischemia/reperfusion injury. This study was strongly focused on 3R's ethic principles, in particular the principle of Reduction. Rats undergoing surgery were treated with pre-surgical tramadol (45 mg/kg intra-peritoneal), or carprofen (5 mg/kg sub-cutaneous), or with pre-surgical administration of carprofen followed by 2 post-surgery tramadol injections (multi-modal group). We assessed behavioral signs of pain and made a subjective evaluation of stress and suffering one and two hours after surgery. Multi-modal treatment significantly reduced the number of signs of pain compared to carprofen alone at both the first hour (61±42 vs 123±47; p<0.05) and the second hour (43±21 vs 74±24; p<0.05) post-surgery. Tramadol alone appeared as effective as multi-modal treatment during the first hour, but signs of pain significantly increased one hour later (from 66±72 to 151±86, p<0.05). Carprofen alone was more effective at the second hour post-surgery when signs of pain reduced to 74±24 from 113±40 in the first hour (p<0.05). Stress behaviors during the second hour were observed in only 20% of rats in the multimodal group compared to 75% and 86% in the carprofen and tramadol groups, respectively (p<0.05). Multi-modal treatment with carprofen and tramadol was more effective in preventing pain during the second hour after surgery compared with both tramadol or carprofen. Our results suggest that the combination of carprofen and tramadol represent the best therapy to prevent animal pain after myocardial ischemia/reperfusion. We obtained our results

  8. Rat Experimental Model of Myocardial Ischemia/Reperfusion Injury: An Ethical Approach to Set up the Analgesic Management of Acute Post-Surgical Pain

    PubMed Central

    Ciuffreda, Maria Chiara; Tolva, Valerio; Casana, Renato; Gnecchi, Massimiliano; Vanoli, Emilio; Spazzolini, Carla; Roughan, John; Calvillo, Laura

    2014-01-01

    Rationale During the past 30 years, myocardial ischemia/reperfusion injury in rodents became one of the most commonly used model in cardiovascular research. Appropriate pain-prevention appears critical since it may influence the outcome and the results obtained with this model. However, there are no proper guidelines for pain management in rats undergoing thoracic surgery. Accordingly, we evaluated three analgesic regimens in cardiac ischemia/reperfusion injury. This study was strongly focused on 3R’s ethic principles, in particular the principle of Reduction. Methods Rats undergoing surgery were treated with pre-surgical tramadol (45 mg/kg intra-peritoneal), or carprofen (5 mg/kg sub-cutaneous), or with pre-surgical administration of carprofen followed by 2 post-surgery tramadol injections (multi-modal group). We assessed behavioral signs of pain and made a subjective evaluation of stress and suffering one and two hours after surgery. Results Multi-modal treatment significantly reduced the number of signs of pain compared to carprofen alone at both the first hour (61±42 vs 123±47; p<0.05) and the second hour (43±21 vs 74±24; p<0.05) post-surgery. Tramadol alone appeared as effective as multi-modal treatment during the first hour, but signs of pain significantly increased one hour later (from 66±72 to 151±86, p<0.05). Carprofen alone was more effective at the second hour post-surgery when signs of pain reduced to 74±24 from 113±40 in the first hour (p<0.05). Stress behaviors during the second hour were observed in only 20% of rats in the multimodal group compared to 75% and 86% in the carprofen and tramadol groups, respectively (p<0.05). Conclusions Multi-modal treatment with carprofen and tramadol was more effective in preventing pain during the second hour after surgery compared with both tramadol or carprofen. Our results suggest that the combination of carprofen and tramadol represent the best therapy to prevent animal pain after myocardial ischemia

  9. Voluntary wheel running delays disease onset and reduces pain hypersensitivity in early experimental autoimmune encephalomyelitis (EAE).

    PubMed

    Benson, Curtis; Paylor, John W; Tenorio, Gustavo; Winship, Ian; Baker, Glen; Kerr, Bradley J

    2015-09-01

    Multiple sclerosis (MS) is classically defined by motor deficits, but it is also associated with the secondary symptoms of pain, depression, and anxiety. Up to this point modifying these secondary symptoms has been difficult. There is evidence that both MS and the animal model experimental autoimmune encephalomyelitis (EAE), commonly used to study the pathophysiology of the disease, can be modulated by exercise. To examine whether limited voluntary wheel running could modulate EAE disease progression and the co-morbid symptoms of pain, mice with EAE were allowed access to running wheels for 1h every day. Allowing only 1h every day of voluntary running led to a significant delay in the onset of clinical signs of the disease. The development of mechanical allodynia was assessed using Von Frey hairs and indicated that wheel running had a modest positive effect on the pain hypersensitivity associated with EAE. These behavioral changes were associated with reduced numbers of cFOS and phosphorylated NR1 positive cells in the dorsal horn of the spinal cord compared to no-run EAE controls. In addition, within the dorsal horn, voluntary wheel running reduced the number of infiltrating CD3(+) T-cells and reduced the overall levels of Iba1 immunoreactivity. Using high performance liquid chromatography (HPLC), we observed that wheel-running lead to significant changes in the spinal cord levels of the antioxidant glutathione. Oxidative stress has separately been shown to contribute to EAE disease progression and neuropathic pain. Together these results indicate that in mice with EAE, voluntary motor activity can delay the onset of clinical signs and reduce pain symptoms associated with the disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Concept priming and pain: an experimental approach to understanding gender roles in sex-related pain differences.

    PubMed

    Fowler, Stephanie L; Rasinski, Heather M; Geers, Andrew L; Helfer, Suzanne G; France, Christopher R

    2011-04-01

    Prior research has found that sex differences in pain are partially due to individual variations in gender roles. In a laboratory study, we tested the hypothesis that the presence of covert gender role cues can also moderate the extent to which women and men experience pain. Specifically, we varied gender role cues by asking male and female participants to write about instances in which they behaved in a stereotypically feminine, masculine, or neutral manner. Pain and cardiovascular reactivity to the cold pressor task were then assessed. Results revealed that, when primed with femininity, men reported less pain and anxiety from the cold pressor task than women. However, no differences existed between the sexes in the masculine or neutral prime conditions. The results indicate that covert gender cues can alter pain reports. Further, at least in some situations, feminine role cues may be more influential on pain reports than masculine role cues.

  11. Effects of hypnotic analgesia and virtual reality on the reduction of experimental pain among high and low hypnotizables.

    PubMed

    Enea, Violeta; Dafinoiu, Ion; Opriş, David; David, Daniel

    2014-01-01

    This research compared a no-treatment control condition and 3 experimentally induced pain treatment conditions: (a) virtual reality distraction (VRD), (b) hypnotic analgesia (HA), and (c) HA + VRD in relieving finger-pressure pain. After receiving baseline pain stimulus, each participant received hypnosis or no hypnosis, followed by VRD or no VRD during another pain stimulus. The data analysis indicated that, overall, all 3 treatments were more effective compared to the control group, irrespective of whether it involved hypnotic analgesia, virtual reality distraction, or both (hypnosis and virtual reality). Nevertheless, the participants responded differently to the pain treatment, depending on the hypnotizability level. High hypnotizables reported hypnotic analgesia, but low hypnotizables did not show hypnotic analgesia. VR distraction reduced pain regardless of hypnotizability.

  12. Treatment Approaches for Interstitial Cystitis: Multimodality Therapy

    PubMed Central

    Evans, Robert J

    2002-01-01

    Interstitial cystitis is an increasingly common disease characterized by urgency, frequency, and pelvic pain. Its etiology is poorly understood but is likely to be multifactorial. A proposed pathophysiology describing a cascade of events, including epithelial dysfunction, mast cell activation, and neurogenic inflammation, is presented. Using this model, multimodality therapy regimens have been developed that treat all components of this cascade. Multimodality therapy appears more effective than single agents in the treatment of interstitial cystitis. PMID:16986029

  13. IL-17 is not essential for inflammation and chronic pelvic pain development in an experimental model of chronic prostatitis/chronic pelvic pain syndrome.

    PubMed

    Motrich, Ruben D; Breser, María L; Sánchez, Leonardo R; Godoy, Gloria J; Prinz, Immo; Rivero, Virginia E

    2016-03-01

    Pain and inflammation in the absence of infection are hallmarks in chronic prostatitis and chronic pelvic pain syndrome (CP/CPPS) patients. The etiology of CP/CPPS is unclear, and autoimmunity has been proposed as a cause. Experimental autoimmune prostatitis (EAP) models have long been used for studying CP/CPPS. Herein, we studied prostate inflammation induction and chronic pelvic pain development in EAP using IL-12p40-KO, IL-4-KO, IL-17-KO, and wild-type (C57BL/6) mice. Prostate antigen (PAg) immunization in C57BL/6 mice induced specific Th1 and Th17 immune responses and severe prostate inflammation and cell infiltration, mainly composed of CD4 T cells and macrophages. Moreover, chronic pelvic pain was evidenced by increased allodynia responses. In immunized IL-17-KO mice, the presence of a prominent PAg-specific Th1 immune response caused similar prostate inflammation and chronic pelvic pain. Furthermore, markedly high PAg-specific Th1 immune responses, exacerbated prostate inflammation, and chronic pelvic pain were detected in immunized IL-4-KO mice. Conversely, immunized IL-12p40-KO mice developed PAg-specific Th2 immune responses, characterized by high IL-4 secretion and neither infiltration nor damage in the prostate. As observed in wild-type control animals, IL12p40-KO mice did not evidence tactile allodynia responses. Our results suggest that, as in patients, chronic pelvic pain is a consequence of prostate inflammation. After PAg immunization, a Th1-associated immune response develops and induces prostate inflammation and chronic pelvic pain. The absence of Th1 or Th2 cytokines, respectively, diminishes or enhances EAP susceptibility. In addition, IL-17 showed not to be essential for pathology induction and chronic pelvic pain development.

  14. Effect of endocannabinoid degradation on pain: role of FAAH polymorphisms in experimental and postoperative pain in women treated for breast cancer.

    PubMed

    Cajanus, Kristiina; Holmström, Emil J; Wessman, Maija; Anttila, Verneri; Kaunisto, Mari A; Kalso, Eija

    2016-02-01

    Fatty acid amide hydrolase (FAAH) metabolizes the endocannabinoid anandamide, which has an important role in nociception. We investigated the role of common FAAH single-nucleotide polymorphisms (SNPs) in experimentally induced and postoperative pain. One thousand women undergoing surgery for breast cancer participated in the study. They were tested for cold (n = 900) and heat pain (n = 1000) sensitivity. After surgery, their pain intensities and analgesic consumption were carefully registered. FAAH genotyping was performed using MassARRAY platform and genome-wide chip (n = 926). Association between 8 FAAH SNPs and 9 pain phenotypes was analyzed using linear regression models. The results showed that carrying 2 copies of a missense variant converting proline at position 129 to threonine (rs324420) resulted in significantly lower cold pain sensitivity and less need for postoperative analgesia. More specifically, rs324420 and another highly correlated SNP, rs1571138, associated significantly with cold pain intensity (corrected P value, 0.0014; recessive model). Patients homozygous for the minor allele (AA genotype) were less sensitive to cold pain (β = -1.48; 95% CI, -2.14 to -0.8). Two other SNPs (rs3766246 and rs4660928) showed nominal association with cold pain, and SNPs rs4141964, rs3766246, rs324420, and rs1571138 nominal association with oxycodone consumption. In conclusion, FAAH gene variation was shown to associate with cold pain sensitivity with P129T/rs324420 being the most likely causal variant as it is known to reduce the FAAH enzyme activity. The same variant showed nominal association with postoperative oxycodone consumption. Our conclusions are, however, limited by the lack of replication and the results should be replicated in an independent cohort.

  15. Multimodal eye recognition

    NASA Astrophysics Data System (ADS)

    Zhou, Zhi; Du, Yingzi; Thomas, N. L.; Delp, Edward J., III

    2010-04-01

    Multimodal biometrics use more than one means of biometric identification to achieve higher recognition accuracy, since sometimes a unimodal biometric is not good enough used to do identification and classification. In this paper, we proposed a multimodal eye recognition system, which can obtain both iris and sclera patterns from one color eye image. Gabor filter and 1-D Log-Gabor filter algorithms have been applied as the iris recognition algorithms. In sclera recognition, we introduced automatic sclera segmentation, sclera pattern enhancement, sclera pattern template generation, and sclera pattern matching. We applied kernelbased matching score fusion to improve the performance of the eye recognition system. The experimental results show that the proposed eye recognition method can achieve better performance compared to unimodal biometric identification, and the accuracy of our proposed kernel-based matching score fusion method is higher than two classic linear matching score fusion methods: Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA).

  16. Emotional modulation of experimental pain: a source imaging study of laser evoked potentials

    PubMed Central

    Stancak, Andrej; Fallon, Nicholas

    2013-01-01

    Negative emotions have been shown to augment experimental pain. As induced emotions alter brain activity, it is not clear whether pain augmentation during noxious stimulation would be related to neural activation existing prior to onset of a noxious stimulus or alternatively, whether emotional stimuli would only alter neural activity during the period of nociceptive processing. We analyzed the spatio-temporal patterns of laser evoked potentials (LEPs) occurring prior to and during the period of cortical processing of noxious laser stimuli during passive viewing of negative, positive, or neutral emotional pictures. Independent component analysis (ICA) was applied to series of source activation volumes, reconstructed using local autoregressive average model (LAURA). Pain was the strongest when laser stimuli were associated with negative emotional pictures. Prior to laser stimulus and during the first 100 ms after onset of laser stimulus, activations were seen in the left and right medial temporal cortex, cerebellum, posterior cingulate, and rostral cingulate/prefrontal cortex. In all these regions, positive or neutral pictures showed stronger activations than negative pictures. During laser stimulation, activations in the right and left anterior insula, temporal cortex and right anterior and posterior parietal cortex were stronger during negative than neutral or positive emotional pictures. Results suggest that negative emotional stimuli increase activation in the left and right anterior insula and temporal cortex, and right posterior and anterior parietal cortex only during the period of nociceptive processing. The role of background brain activation in emotional modulation of pain appears to be only permissive, and consisting in attenuation of activation in structures maintaining the resting state of the brain. PMID:24062659

  17. The effect of experimental pain on motor training performance and sensorimotor integration.

    PubMed

    Dancey, Erin; Murphy, Bernadette; Srbely, John; Yielder, Paul

    2014-09-01

    Experimental pain is known to affect neuroplasticity of the motor cortex as well as motor performance, but less is known about neuroplasticity of somatosensory processing in the presence of pain. Early somatosensory evoked potentials (SEPs) provide a mechanism for investigating alterations in sensory processing and sensorimotor integration (SMI). The overall aim of this study was to investigate the interactive effects of acute pain, motor training, and sensorimotor processing. Two groups of twelve participants (N = 24) were randomly assigned to either an intervention (capsaicin cream) or placebo (inert lotion) group. SEP amplitudes were collected by stimulation of the median nerve at baseline, post-application and post-motor training. Participants performed a motor sequence task while reaction time and accuracy data were recorded. The amplitude of the P22-N24 complex was significantly increased following motor training for both groups F(2,23) = 3.533, p < 0.05, while Friedman's test for the P22-N30 complex showed a significant increase in the intervention group [χ(2) (df = 2, p = 0.016) = 8.2], with no significant change in the placebo group. Following motor training, reaction time was significantly decreased for both groups F(1,23) = 59.575, p < 0.01 and overall accuracy differed by group [χ(2) (df = 3, p < 0.001) = 19.86], with post hoc testing indicating that the intervention group improved in accuracy following motor training [χ(2) (df = 1, p = 0.001) = 11.77] while the placebo group had worse accuracy [χ(2) (df = 1, p = 0.006) = 7.67]. The improved performance in the presence of capsaicin provides support for the enhancement of knowledge acquisition with the presence of nontarget stimuli. In addition, the increase in SEP peak amplitudes suggests that early SEP changes are markers of SMI changes accompanying motor training and acute pain.

  18. Can personality traits and gender predict the response to morphine? An experimental cold pain study.

    PubMed

    Pud, Dorit; Yarnitsky, David; Sprecher, Elliot; Rogowski, Zeev; Adler, Rivka; Eisenberg, Elon

    2006-02-01

    The aim of the present study was to examine the possible role of personality traits, in accordance with Cloninger's theory, and gender, in the variability of responsiveness to opioids. Specifically, it was intended to test whether or not the three personality dimensions - harm avoidance (HA), reward dependence (RD) and novelty seeking (NS) - as suggested by Cloninger, can predict inter-personal differences in responsiveness to morphine after exposure to experimental cold pain. Thirty-four healthy volunteers (15 females, 19 males) were given the cold pressor test (CPT). Pain threshold, tolerance, and magnitude (VAS) were measured before and after (six measures, 30 min apart) the administration of either 0.5 mg/kg oral morphine sulphate (n=21) or 0.33 mg/kg oral active placebo (diphenhydramine) (n=13) in a randomized, double blind design. Assessment of the three personality traits, according to Cloninger's Tridimensional Personality Questionnaire, was performed before the CPT. A high HA score (but not RD, NS, or baseline values of the three pain parameters) predicted a significantly larger pain relief following the administration of morphine sulphate (but not of the placebo). Women exhibited a larger response in response to both treatments, as indicated by a significantly increased threshold and tolerance following morphine sulphate as well as significantly increased tolerance and decreased magnitude following placebo administration. The present study confirms the existence of individual differences in response to analgesic treatment. It suggests that high HA personality trait is associated with better responsiveness to morphine treatment, and that females respond better than men to both morphine and placebo.

  19. Effects of experimental tooth clenching on pain and intramuscular release of 5-HT and glutamate in patients with myofascial TMD.

    PubMed

    Dawson, Andreas; Ghafouri, Bijar; Gerdle, Björn; List, Thomas; Svensson, Peter; Ernberg, Malin

    2015-08-01

    It has been suggested that tooth clenching may be associated with local metabolic changes, and is a risk factor for myofascial temporomandibular disorders (M-TMD). This study investigated the effects of experimental tooth clenching on the levels of 5-HT, glutamate, pyruvate, and lactate, as well as on blood flow and pain intensity, in the masseter muscles of M-TMD patients. Fifteen patients with M-TMD and 15 pain-free controls participated. Intramuscular microdialysis was performed to collect 5-HT, glutamate, pyruvate, and lactate and to assess blood flow. Two hours after the insertion of a microdialysis catheter, participants performed a 20-minute repetitive tooth clenching task (50% of maximal voluntary contraction). Pain intensity was measured throughout. A significant effect of group (P<0.01), but not of time, was observed on 5-HT levels and blood flow. No significant effects of time or group occurred on glutamate, pyruvate, or lactate levels. Time and group had significant main effects on pain intensity (P<0.05 and <0.001). No significant correlations were identified between: (1) 5-HT, glutamate, and pain intensity; or between (2) pyruvate, lactate, and blood flow. This experimental tooth clenching model increased jaw muscle pain levels in M-TMD patients and evoked low levels of jaw muscle pain in controls. M-TMD patients had significantly higher levels of 5-HT than controls and significantly lower blood flow. These 2 factors may facilitate the release of other algesic substances that may cause pain.

  20. Does experimental low back pain change posteroanterior lumbar spinal stiffness and trunk muscle activity? A randomized crossover study.

    PubMed

    Wong, Arnold Y L; Parent, Eric C; Prasad, Narasimha; Huang, Christopher; Chan, K Ming; Kawchuk, Gregory N

    2016-05-01

    While some patients with low back pain demonstrate increased spinal stiffness that decreases as pain subsides, this observation is inconsistent. Currently, the relation between spinal stiffness and low back pain remains unclear. This study aimed to investigate the effects of experimental low back pain on temporal changes in posteroanterior spinal stiffness and concurrent trunk muscle activity. In separate sessions five days apart, nine asymptomatic participants received equal volume injections of hypertonic or isotonic saline in random order into the L3-L5 interspinous ligaments. Pain intensity, spinal stiffness (global and terminal stiffness) at the L3 level, and the surface electromyographic activity of six trunk muscles were measured before, immediately after, and 25-minute after injections. These outcome measures under different saline conditions were compared by generalized estimating equations. Compared to isotonic saline injections, hypertonic saline injections evoked significantly higher pain intensity (mean difference: 5.7/10), higher global (mean difference: 0.73N/mm) and terminal stiffness (mean difference: 0.58N/mm), and increased activity of four trunk muscles during indentation (P<0.05). Both spinal stiffness and trunk muscle activity returned to baseline levels as pain subsided. While previous clinical research reported inconsistent findings regarding the association between spinal stiffness and low back pain, our study revealed that experimental pain caused temporary increases in spinal stiffness and concurrent trunk muscle co-contraction during indentation, which helps explain the temporal relation between spinal stiffness and low back pain observed in some clinical studies. Our results substantiate the role of spinal stiffness assessments in monitoring back pain progression. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. A Multimodal Evaluation of the Comparative Efficacy of Yoga versus a Patient Centered Support Group for Treating Chronic Pain in Gulf War Illness

    DTIC Science & Technology

    2016-10-01

    Pain, Pathologic Processes, Signs and Symptoms. 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UU 18. NUMBER OF PAGES 12 19a. NAME OF...Attributes, Nervous System Diseases, Neurologic Manifestations, Pain, Pathologic Processes, Signs and Symptoms.   3. ACCOMPLISHMENTS: The PI is...veterans: evidence for efficacy in treating musculoskeletal pain.” Stanton, M.V., Cho, R.H., Mahoney, L., Moore- Downing, D., Avery, T., Varni, J.M

  2. A Multimodal Evaluation of the Comparative Efficacy of Yoga Versus a Patient-Centered Support Group for Treating Chronic Pain in Gulf War Illness

    DTIC Science & Technology

    2015-10-01

    Treating Chronic Pain in Gulf War Illness PRINCIPAL INVESTIGATOR: Peter Bayley, PhD RECIPIENT: PALO ALTO VETERANS INSTITUTE FOR RESEARCH Palo Alto...Patient-Centered Support Group for Treating Chronic Pain in Gulf War Illness 5a. CONTRACT NUMBER W81XWH-14-1-0615 5b. GRANT NUMBER 5c. PROGRAM...Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT The primary objective is to investigate yoga for the treatment of chronic pain in veterans with Gulf War

  3. The Role of Multimodal Analgesia in Spine Surgery.

    PubMed

    Kurd, Mark F; Kreitz, Tyler; Schroeder, Gregory; Vaccaro, Alexander R

    2017-04-01

    Optimal postoperative pain control allows for faster recovery, reduced complications, and improved patient satisfaction. Historically, pain management after spine surgery relied heavily on opioid medications. Multimodal regimens were developed to reduce opioid consumption and associated adverse effects. Multimodal approaches used in orthopaedic surgery of the lower extremity, especially joint arthroplasty, have been well described and studies have shown reduced opioid consumption, improved pain and function, and decreased length of stay. A growing body of evidence supports multimodal analgesia in spine surgery. Methods include the use of preemptive analgesia, NSAIDs, the neuromodulatory agents gabapentin and pregabalin, acetaminophen, and extended-action local anesthesia. The development of a standard approach to multimodal analgesia in spine surgery requires extensive assessment of the literature. Because a substantial number of spine surgeries are performed annually, a standardized approach to multimodal analgesia may provide considerable benefits, particularly in the context of the increased emphasis on accountability within the healthcare system.

  4. [Chronic postoperative pain].

    PubMed

    Cachemaille, Matthieu; Blanc, Catherine

    2016-06-22

    Chronic postoperative pain remains a frequent pathology whose global impact approximates 20 and 30% and accounts for 20% of the consultations in a pain center. Risk factors consider firstly each patient's feature and comorbidity and also different surgical procedures with their technical approach. Neuropathic pain compared to nociceptive pain is a great component in the postoperative period and needs to be recognized by specific tests (DN4). Pain prevention involves risk factors' detection, appropriate anesthetic support and effective postoperative pain management. Treatment is based on the type of pain and includes a multimodal analgesia with interventional pain therapy.

  5. A pragmatic community-based intervention of multimodal physiotherapy plus deep water running (DWR) for fibromyalgia syndrome: a pilot study.

    PubMed

    Cuesta-Vargas, Antonio I; Adams, Nicola

    2011-11-01

    Evidence-based recommendations support the use of multimodal therapy and hydrotherapy for fibromyalgia syndrome; however, there is little standardisation of such programmes. The aim of the study was to assess the effectiveness of a pool-based exercise using deep water running (DWR) as part of a multimodal physiotherapy programme for patients with fibromyalgia syndrome. For a non-randomised clinical study, 44 patients diagnosed with fibromyalgia were recruited from primary care. Patients in the experimental group received a multimodal programme incorporating pool-based exercise using DWR three times a week for an 8-week period. The control group received a leaflet containing advice and continued with normal activities. Patients were evaluated for physical function (Fibromyalgia Impact Questionnaire, FIQ), pain, general health (Short Form-12 Health Survey) and quality of life (European Quality of Life Scale-5D) pre- and post intervention. Statistically significant results were found for the experimental group for FIQ total score, incorporating physical function, pain, fatigue, stiffness and psychological variables (p < 0.05). Statistically significant differences between the experimental group and control were also found for general health (p < 0.05) and quality of life (p < 0.05). The results of this pilot study and the high level of compliance and adherence and low level of attrition suggest that this multimodal programme incorporating DWR is a safe and effective intervention for fibromyalgia syndrome that is acceptable to patients.

  6. Center of Pressure Displacement of Standing Posture during Rapid Movements Is Reorganised Due to Experimental Lower Extremity Muscle Pain

    PubMed Central

    Shiozawa, Shinichiro; Hirata, Rogerio Pessoto; Graven-Nielsen, Thomas

    2015-01-01

    Background Postural control during rapid movements may be impaired due to musculoskeletal pain. The purpose of this study was to investigate the effect of experimental knee-related muscle pain on the center of pressure (CoP) displacement in a reaction time task condition. Methods Nine healthy males performed two reaction time tasks (dominant side shoulder flexion and bilateral heel lift) before, during, and after experimental pain induced in the dominant side vastus medialis or the tibialis anterior muscles by hypertonic saline injections. The CoP displacement was extracted from the ipsilateral and contralateral side by two force plates and the net CoP displacement was calculated. Results Compared with non-painful sessions, tibialis anterior muscle pain during the peak and peak-to-peak displacement for the CoP during anticipatory postural adjustments (APAs) of the shoulder task reduced the peak-to-peak displacement of the net CoP in the medial-lateral direction (P<0.05). Tibialis anterior and vastus medialis muscle pain during shoulder flexion task reduced the anterior-posterior peak-to-peak displacement in the ipsilateral side (P<0.05). Conclusions The central nervous system in healthy individuals was sufficiently robust in maintaining the APA characteristics during pain, although the displacement of net and ipsilateral CoP in the medial-lateral and anterior-posterior directions during unilateral fast shoulder movement was altered. PMID:26680777

  7. Inflammation-induced hyperalgesia: effects of timing, dosage, and negative affect on somatic pain sensitivity in human experimental endotoxemia.

    PubMed

    Wegner, Alexander; Elsenbruch, Sigrid; Maluck, Janina; Grigoleit, Jan-Sebastian; Engler, Harald; Jäger, Marcus; Spreitzer, Ingo; Schedlowski, Manfred; Benson, Sven

    2014-10-01

    Inflammation-induced pain amplification and hypersensitivity play a role in the pathophysiology of numerous clinical conditions. Experimental endotoxemia has recently been implemented as model to analyze immune-mediated processes in human pain. In this study, we aimed to analyze dose- and time-dependent effects of lipopolysaccharide (LPS) on clinically-relevant pain models for musculoskeletal and neuropathic pain as well as the interaction among LPS-induced changes in inflammatory markers, pain sensitivity and negative affect. In this randomized, double-blind, placebo-controlled study, healthy male subjects received an intravenous injection of either a moderate dose of LPS (0.8 ng/kg Escherichiacoli), low-dose LPS (0.4 ng/kg), or saline (placebo control group). Pressure pain thresholds (PPT), mechanical pain sensitivity (MPS), and cold pain sensitivity (CP) were assessed before and 1, 3, and 6h post injection to assess time-dependent LPS effects on pain sensitivity. Plasma cytokines (TNF-α, IL-6, IL-8, IL-10) and state anxiety were repeatedly measured before, and 1, 2, 3, 4, and 6h after injection of LPS or placebo. LPS administration induced a systemic immune activation, reflected by significant increases in cytokine levels, body temperature, and negative mood with pronounced effects to the higher LPS dose. Significant decreases of PPTs were observed only 3h after injection of the moderate dose of LPS (0.8 ng/kg). MPS and CP were not affected by LPS-induced immune activation. Correlation analyses revealed that decreased PPTs were associated with peak IL-6 increases and negative mood. Our results revealed widespread increases in musculoskeletal pain sensitivity in response to a moderate dose of LPS (0.8 ng/kg), which correlate both with changes in IL-6 and negative mood. These data extend and refine existing knowledge about immune mechanisms mediating hyperalgesia with implications for the pathophysiology of chronic pain and neuropsychiatric conditions. Copyright

  8. Observer influences on pain: an experimental series examining same-sex and opposite-sex friends, strangers, and romantic partners.

    PubMed

    Edwards, Rhiannon; Eccleston, Christopher; Keogh, Edmund

    2017-05-01

    Despite the well-documented sex and gender differences, little is known about the relative impact of male-female social interactions on pain. Three experiments were conducted to investigate whether the type of interpersonal relationship men and women have with an observer affects how they respond to experimental pain. Study 1 recruited friends and strangers, study 2 examined the effects of same- and opposite-sex friends, whereas study 3 investigated the differences between opposite-sex friends and opposite-sex romantic partners. One hundred forty-four dyads were recruited (48 in each study). One person from each dyad completed 2 pain tasks, whereas the other person observed in silence. Overall, the presence of another person resulted in an increase in pain threshold and tolerance on the cold-pressor task and algometer. The sex status of the dyads also had a role, but only within the friendship groups. In particular, male friends had the most pronounced effect on men's pain, increasing pain tolerance. We suggest that the presence of an observer, their sex, and the nature of the participant-observer relationship all influence how pain is reported. Further research should focus on dyadic relationships, and their influence on how men and women report and communicate pain in specific contexts.

  9. Experimentally induced masseter-pain changes masseter but not sternocleidomastoid muscle-related activity during mastication.

    PubMed

    Pasinato, Fernanda; Santos-Couto-Paz, Clarissa C; Zeredo, Jorge Luis Lopes; Macedo, Sergio Bruzadelli; Corrêa, Eliane C R

    2016-12-01

    The aim of this study was to verify the effects of induced masseter-muscle pain on the amplitude of muscle activation, symmetry and coactivation of jaw- and neck-muscles during mastication. Twenty-eight male volunteers, mean age±SD 20.6±2.0years, participated in this study. Surface electromyography of the masseter and sternocleidomastoid (SCM) muscles was performed bilaterally during mastication of a gummy candy before and after injections of monosodium glutamate solution and isotonic saline solution. As a result, we observed a decrease in the amplitude of activation of the masseter muscle on the working side (p=0.009; d=0.34) and a reduction in the asymmetry between the working and the balancing side during mastication (p=0.007; d=0.38). No changes were observed either on the craniocervical electromyographic variables. In conclusion, experimentally induced pain reduced the masseter muscle activation on the working side, thereby reducing the physiological masseters' recruitment asymmetry between the two sides during mastication. No effects on SCM activity were detected. These results may partly explain the initial maladaptative changes underlying TMD conditions.

  10. Does electrode placement influence tens-induced antihyperalgesia in experimental inflammatory pain model?

    PubMed

    Neto, Maurício L Poderoso; Maciel, Leonardo Y S; Cruz, Kamilla M L; Filho, Valter J Santana; Bonjardim, Leonardo R; DeSantana, Josimari M

    Transcutaneous electrical nerve stimulation (TENS) is a treatment commonly used for managing pain; however, the ideal placement of the electrodes is not fully understood. To investigate the best way to apply TENS electrodes in an experimental inflammatory pain model. Knee joint inflammation was induced in rats, followed by administration of low-frequency TENS (4Hz) under anesthesia for five days. Animals were randomly allocated to five groups according to electrode placement (n=6, each): dermatome, contralateral, paraspinal, acupoint, and control. Low-frequency TENS at sensory intensity and 100μs pulse duration. Withdrawal thresholds to mechanical (von Frey) and thermal stimuli and joint edema were assessed before induction of inflammation and immediately before and after application of TENS. Reduced paw withdrawal threshold and thermal latency that occur 24h after the induction of inflammation were significantly reversed by the administration of TENS in all groups when compared with sham treatment or with the condition before TENS treatment. No difference was observed in the edema measurement. These results offer more options for practitioners to choose the area of the body most commodious for electrode placement, depending on the clinical condition of the patient, because the effect was similar at all sites. In addition, there was a loss of the effectiveness of TENS in reversing mechanical and thermal hyperalgesia on the fifth day, suggesting the development of the tolerance phenomenon. Copyright © 2017. Publicado por Elsevier Editora Ltda.

  11. Differential sensitivity of three experimental pain models in detecting the analgesic effects of transdermal fentanyl and buprenorphine.

    PubMed

    Koltzenburg, Martin; Pokorny, Rolf; Gasser, Urs E; Richarz, Ute

    2006-12-15

    This is the first randomized controlled trial that tests the analgesic efficacy of transdermally delivered opioids in healthy volunteers and that assesses the sensitivity of different experimental pain tests to detect analgesia in this setting. Transdermal application of the full agonist fentanyl (TDF: 12.5 or 25 microg/h) and the partial agonist buprenorphine (TDB: 35 microg/h) was compared in three experimental models of acute pain (heat pain, painful electrical stimulation, cold pressor) in a double-blind, randomized, placebo-controlled, 4-arm crossover study with 20 healthy subjects (15 men, 5 women). Patches were administered for 72 h and pain levels measured at baseline and 24 and 72 h, with an 11-day wash-out. The cold pressor test was most sensitive to analgesic effects, with significant reductions in area under the pain intensity curve for all active compounds at 24 h (average reductions: 14% TDF 12.5 microg/h, 35% TDF 25 microg/h, 43% TDB 35 microg/h). There were significant increases in heat pain threshold for TDF 25 microg/h and TDB 35 microg/h. Painful electrical stimulation failed to demonstrate an analgesic effect. The magnitude of analgesia in the cold pressor model showed some correlation with TDF dosage and comparable effects for the full agonist fentanyl and the partial agonist buprenorphine. We conclude that the cold pressor test was most sensitive to analgesic effects in healthy subjects and that a transdermal dose of 12.5 microg/h fentanyl achieved significant pain reduction compared with placebo. Subjects experienced opioid-typical AEs including dizziness, nausea and vomiting. No serious AEs occurred.

  12. Effect of experimental low back pain on neuromuscular control of the trunk in healthy volunteers and patients with chronic low back pain.

    PubMed

    Dubois, Jean-Daniel; Piché, Mathieu; Cantin, Vincent; Descarreaux, Martin

    2011-10-01

    Studies of electromyographic (EMG) activity and lumbopelvic rhythm have led to a better understanding of neuromuscular alterations in chronic low back pain (cLBP) patients. Whether these changes reflect adaptations to chronic pain or are induced by acute pain is still unclear. This work aimed to assess the effects of experimental LBP on lumbar erector spinae (LES) EMG activity and lumbopelvic kinematics during a trunk flexion-extension task in healthy volunteers and LBP patients. The contribution of disability to these effects was also examined. Twelve healthy participants and 14 cLBP patients performed flexion-extension tasks in three conditions; control, innocuous heat and noxious heat, applied on the skin over L5 or T7. The results indicated that noxious heat at L5 evoked specific increases in LES activity during static full trunk flexion and extension, irrespective of participants' group. Kinematic data suggested that LBP patients adopted a different movement strategy than controls when noxious heat was applied at the L5 level. Besides, high disability was associated with less kinematic changes when approaching and leaving full flexion. These results indicate that experimental pain can induce neuromechanical alterations in cLBP patients and healthy volunteers, and that higher disability in patients is associated with decreased movement pattern changes.

  13. Effects of experimentally induced low back pain on the sit-to-stand movement and electroencephalographic contingent negative variation

    PubMed Central

    Jacobs, Jesse V.; Yaguchi, Chie; Kaida, Chizuru; Irei, Mariko; Naka, Masami; Henry, Sharon M.; Fujiwara, Katsuo

    2011-01-01

    It is becoming increasingly evident that people with chronic, recurrent low back pain (LBP) exhibit changes in cerebrocortical activity that associate with altered postural coordination, suggesting a need for a better understanding of how the experience of LBP alters postural coordination and cerebrocortical activity. To characterize changes in postural coordination and pre-movement cerebrocortical activity related to the experience of acutely induced LBP, 14 healthy participants with no history of LBP performed sit-to-stand movements in 3 sequential conditions: (1) without experimentally induced LBP; NoPain1, (2) with movement-associated LBP induced by electrocutaneous stimulation; Pain, and (3) again without induced LBP; NoPain2. The Pain condition elicited altered muscle activation and redistributed forces under the seat and feet prior to movement, decreased peak vertical force exerted under the feet during weight transfer, longer movement times, as well as decreased and earlier peak hip extension. Stepwise regression models demonstrated that electroencephalographic amplitudes of contingent negative variation during the Pain condition significantly correlated with the participants’ change in sit-to-stand measures between the NoPain1 and Pain conditions, as well as with the subsequent difference in sit-to-stand measures between the NoPain1 and NoPain2 conditions. The results, therefore, identify the contingent negative variation as a correlate for the extent of an individual’s LBP-related movement modifications and to the subsequent change in movement patterns from before to after the experience of acutely induced LBP, thereby providing a direction for future studies aimed to understand the neural mechanisms underlying the development of altered movement patterns with LBP. PMID:21952791

  14. Sleep Fragmentation Hypersensitizes Healthy Young Women to Deep and Superficial Experimental Pain.

    PubMed

    Iacovides, Stella; George, Kezia; Kamerman, Peter; Baker, Fiona C

    2017-07-01

    The effect of sleep deprivation on pain sensitivity has typically been studied using total and partial sleep deprivation protocols. These protocols do not mimic the fragmented pattern of sleep disruption usually observed in individuals with clinical pain conditions. Therefore, we conducted a controlled experiment to investigate the effect of sleep fragmentation on pain perception (deep pain: forearm muscle ischemia, and superficial pain: graded pin pricks applied to the skin) in 11 healthy young women after 2 consecutive nights of sleep fragmentation, compared with a normal night of sleep. Compared with normal sleep, sleep fragmentation resulted in significantly poorer sleep quality, morning vigilance, and global mood. Pin prick threshold decreased significantly (increased sensitivity), as did habituation to ischemic muscle pain (increased sensitivity), over the course of the 2 nights of sleep fragmentation compared with the night of normal sleep. Sleep fragmentation did not increase the maximum pain intensity reported during muscle ischemia (no increase in gain), and nor did it increase the number of spontaneous pains reported by participants. Our data show that sleep fragmentation in healthy, young, pain-free women increases pain sensitivity in superficial and deep tissues, indicating a role for sleep disruption, through sleep fragmentation, in modulating pain perception. Our findings that pain-free, young women develop hyperalgesia to superficial and deep muscle pain after short-term sleep disruption highlight the need for effective sleep management strategies in patients with pain. Findings also suggest the possibility that short-term sleep disruption associated with recurrent acute pain could contribute to increased risk for future chronic pain conditions. Copyright © 2017 American Pain Society. Published by Elsevier Inc. All rights reserved.

  15. Pilot double-blinded study to assess efficacy and tolerability of morphine sulphate oral solution (Oramorph®) given preoperatively as add-on therapy within a multimodal postoperative pain approach in patients undergoing laparoscopic cholecystectomy.

    PubMed

    Fanelli, A; Ghisi, D; Pergolotti, B; Martinotti, M; Fanelli, G; Danelli, G

    2014-01-01

    This study aims at investigating the effect of a single pre-operative oral administration of morphine sulphate (Oramorph®) on pain after laparoscopic cholecystectomy (LC). Forty-one ASA I-III patients, aged 18-65 years, undergoing LC were randomly, double-blindly allocated to treatment (N.=20, 30mg Oramorph®, group M) or placebo (N.=21, group P). General anesthesia was maintained with propofol and remifentanil. All patients received ketamine 0.2 mg/kg iv at induction, intraoperative ketorolac 30mg iv and tramadol postoperatively (iv PCA: bolus 50 mg, lock-out 30 min, max 100 mg/4 hours). Numerical rating scale for pain (NRS), White's fast track and PADSS scores, tramadol consumption and adverse events were recorded for the first 24h. All patients underwent State Trait Anxiety Inventory (STAI) and Mini Mental State Examination (MMSE). Anthropometric characteristics, MMSE, STAI, ASA status, NRS rest, White's and PADDS scores, PONV incidence were similar. Group M showed significantly lower NRS on movement during the first 3 hours after awakening. Cumulative tramadol consumption was lower in group M than in group P (185±142 mg versus 263±199 mg, P=0.199). Within a multimodal approach, a single preoperative oral administration of 30 mg of morphine sulphate in patients undergoing LC did not improve pain at rest, but improved NRS on movement during the first 3 hours after awakening. Group P required a higher mean dose of tramadol compared to Group M, although not significantly. The safety profile of Oramorph® allowed fast extubation and awakening times as well as prompt home discharge within 6 hours from surgery.

  16. Vector-Resonance-Multimode Instability

    NASA Astrophysics Data System (ADS)

    Sergeyev, S. V.; Kbashi, H.; Tarasov, N.; Loiko, Yu.; Kolpakov, S. A.

    2017-01-01

    The modulation and multimode instabilities are the main mechanisms which drive spontaneous spatial and temporal pattern formation in a vast number of nonlinear systems ranging from biology to laser physics. Using an Er-doped fiber laser as a test bed, here for the first time we demonstrate both experimentally and theoretically a new type of a low-threshold vector-resonance-multimode instability which inherits features of multimode and modulation instabilities. The same as for the multimode instability, a large number of longitudinal modes can be excited without mode synchronization. To enable modulation instability, we modulate the state of polarization of the lasing signal with the period of the beat length by an adjustment of the in-cavity birefringence and the state of polarization of the pump wave. As a result, we show the regime's tunability from complex oscillatory to periodic with longitudinal mode synchronization in the case of resonance matching between the beat and cavity lengths. Apart from the interest in laser physics for unlocking the tunability and stability of dynamic regimes, the proposed mechanism of the vector-resonance-multimode instability can be of fundamental interest for the nonlinear dynamics of various distributed systems.

  17. The association between dry needling-induced twitch response and change in pain and muscle function in patients with low back pain: a quasi-experimental study.

    PubMed

    Koppenhaver, Shane L; Walker, Michael J; Rettig, Charles; Davis, Joel; Nelson, Chenae; Su, Jonathan; Fernández-de-Las-Peñas, Cesar; Hebert, Jeffrey J

    2017-06-01

    To investigate the relationship between dry needling-induced twitch response and change in pain, disability, nociceptive sensitivity, and lumbar multifidus muscle function, in patients with low back pain (LBP). Quasi-experimental study. Department of Defense Academic Institution. Sixty-six patients with mechanical LBP (38 men, 28 women, age: 41.3 [9.2] years). Dry needling treatment to the lumbar multifidus muscles between L3 and L5 bilaterally. Examination procedures included numeric pain rating, the Modified Oswestry Disability Index, pressure algometry, and real-time ultrasound imaging assessment of lumbar multifidus muscle function before and after dry needling treatment. Pain pressure threshold (PPT) was used to measure nocioceptive sensitivity. The percent change in muscle thickness from rest to contraction was calculated to represent muscle function. Participants were dichotomized and compared based on whether or not they experienced at least one twitch response on the most painful side and spinal level during dry needling. Participants experiencing local twitch response during dry needling exhibited greater immediate improvement in lumbar multifidus muscle function than participants who did not experience a twitch (thickness change with twitch: 12.4 [6]%, thickness change without twitch: 5.7 [11]%, mean difference adjusted for baseline value, 95%CI: 4.4 [1 to 8]%). However, this difference was not present after 1-week, and there were no between-groups differences in disability, pain intensity, or nociceptive sensitivity. The twitch response during dry needling might be clinically relevant, but should not be considered necessary for successful treatment. Published by Elsevier Ltd.

  18. Pathogenesis and clinical aspects of pain in patients with osteoporosis

    PubMed Central

    Mediati, Rocco Domenico; Vellucci, Renato; Dodaro, Lucia

    2014-01-01

    Summary Bone pain is one of the most frequent kinds of chronic pain, mainly in elderly patients. It causes a significant worsening of functional capacity and deterioration in the quality of life in people affected. Mechanisms of pain in osteoporosis are poorly known and often extrapolated by other pathologies or other experimental model. One of principal causes would be a “hyper-remodeling” of bone, that involves osteoclasts activity and pathological modifications of bone innervation. Several studies show that osteoclasts play a significant role in bone pain etiology. Pain in osteoporosis is mainly nociceptive, if it become persistent a sensitization of peripheral and central nervous system can occur, so underlining the transition to a chronic pain syndrome. Central sensitization mechanisms are complex and involve several neuromediators and receptors (Substance P, NMDA, etc.). Most common manifestations of osteoporosis are vertebral compression fractures that cause persistent pain, though to differentiate from pain originating in structures as joint or muscle. First manifestation can be an acute pain due to pathological fracture, those of hip often causes disability. Pain in osteoporosis is an important clinical challenge. Often its complications and consequences on patient quality of life are underestimated with not negligible social implications. A balanced and early multimodal pain therapy including opioids as necessary, even in cases of acute pain, improve the functional capacity of patients and helps to prevent neurological alterations that seems to contribute in significant way in causing irreversible pain chronic syndromes. PMID:25568647

  19. Experimental muscle pain increases variability of neural drive to muscle and decreases motor unit coherence in tremor frequency band

    PubMed Central

    Yavuz, Utku Ş.; Negro, Francesco; Falla, Deborah

    2015-01-01

    It has been observed that muscle pain influences force variability and low-frequency (<3 Hz) oscillations in the neural drive to muscle. In this study, we aimed to investigate the effect of experimental muscle pain on the neural control of muscle force at higher frequency bands, associated with afferent feedback (alpha band, 5–13 Hz) and with descending cortical input (beta band, 15–30 Hz). Single-motor unit activity was recorded, in two separate experimental sessions, from the abductor digiti minimi (ADM) and tibialis anterior (TA) muscles with intramuscular wire electrodes, during isometric abductions of the fifth finger at 10% of maximal force [maximum voluntary contraction (MVC)] and ankle dorsiflexions at 25% MVC. The contractions were repeated under three conditions: no pain (baseline) and after intramuscular injection of isotonic (0.9%, control) and hypertonic (5.8%, painful) saline. The results showed an increase of the relative power of both the force signal and the neural drive at the tremor frequency band (alpha, 5–13 Hz) between the baseline and hypertonic (painful) conditions for both muscles (P < 0.05) but no effect on the beta band. Additionally, the strength of motor unit coherence was lower (P < 0.05) in the hypertonic condition in the alpha band for both muscles and in the beta band for the ADM. These results indicate that experimental muscle pain increases the amplitude of the tremor oscillations because of an increased variability of the neural control (common synaptic input) in the tremor band. Moreover, the concomitant decrease in coherence suggests an increase in independent input in the tremor band due to pain. PMID:26019314

  20. SVM-based multimodal classification of activities of daily living in Health Smart Homes: sensors, algorithms, and first experimental results.

    PubMed

    Fleury, Anthony; Vacher, Michel; Noury, Norbert

    2010-03-01

    By 2050, about one third of the French population will be over 65. Our laboratory's current research focuses on the monitoring of elderly people at home, to detect a loss of autonomy as early as possible. Our aim is to quantify criteria such as the international activities of daily living (ADL) or the French Autonomie Gerontologie Groupes Iso-Ressources (AGGIR) scales, by automatically classifying the different ADL performed by the subject during the day. A Health Smart Home is used for this. Our Health Smart Home includes, in a real flat, infrared presence sensors (location), door contacts (to control the use of some facilities), temperature and hygrometry sensor in the bathroom, and microphones (sound classification and speech recognition). A wearable kinematic sensor also informs postural transitions (using pattern recognition) and walk periods (frequency analysis). This data collected from the various sensors are then used to classify each temporal frame into one of the ADL that was previously acquired (seven activities: hygiene, toilet use, eating, resting, sleeping, communication, and dressing/undressing). This is done using support vector machines. We performed a 1-h experimentation with 13 young and healthy subjects to determine the models of the different activities, and then we tested the classification algorithm (cross validation) with real data.

  1. Experimental investigation of cognitive and affective empathy in borderline personality disorder: Effects of ambiguity in multimodal social information processing.

    PubMed

    Niedtfeld, Inga

    2017-07-01

    Borderline personality disorder (BPD) is characterized by affective instability and interpersonal problems. In the context of social interaction, impairments in empathy are proposed to result in inadequate social behavior. In contrast to findings of reduced cognitive empathy, some authors suggested enhanced emotional empathy in BPD. It was investigated whether ambiguity leads to decreased cognitive or emotional empathy in BPD. Thirty-four patients with BPD and thirty-two healthy controls were presented with video clips, which were presented through prosody, facial expression, and speech content. Experimental conditions were designed to induce ambiguity by presenting neutral valence in one of these communication channels. Subjects were asked to indicate the actors' emotional valence, their decision confidence, and their own emotional state. BPD patients showed increased emotional empathy when neutral stories comprised nonverbally expressed emotions. In contrast, when all channels were emotional, patients showed lower emotional empathy than healthy controls. Regarding cognitive empathy, there were no significant differences between BPD patients and healthy control subjects in recognition accuracy, but reduced decision confidence in BPD. These results suggest that patients with BPD show altered emotional empathy, experiencing higher rates of emotional contagion when emotions are expressed nonverbally. The latter may contribute to misunderstandings and inadequate social behavior. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  2. [A clinical and experimental study of the role of long-lasting perioperative epidural anesthesia in the prevention of phantom limb pain].

    PubMed

    Ovechkin, A M; Kukushkin, M L; Gnezdilov, A V; Reshetniak, V K

    1994-01-01

    The aim of this study was to investigate the possible onset of phantom limb pain (PLP) and its development depending on preoperative limb pain and type of anesthesia during limb amputation. It was experimentally proved that preliminary local anesthesia of rat sciatic nerve slowed down the development of pain syndrome after the operation as well as reduced the number of rats with pain syndrome, as compared to the group subjected to preliminary painful electrical stimulation of the operated on limb. The clinical data presented reveal a significant reduction in the incidence of PLP after perioperative epidural anesthesia, as compared to patients with preoperative pain operated on under general anesthesia.

  3. Effect of celecoxib on emotional stress and pain-related behaviors evoked by experimental tooth movement in the rat.

    PubMed

    Shibazaki, Tatsunori; Yozgatian, Joseph H; Zeredo, Jorge L; Gonzales, Carmen; Hotokezaka, Hitoshi; Koga, Yoshiyuki; Yoshida, Noriaki

    2009-11-01

    To test the efficacy of an animal model of pain and stress and evaluate the effects of celecoxib administered when orthodontic force is applied. A 20-g reciprocal force was applied via an orthodontic appliance to the maxillary left first and second molars of 7-week-old male Sprague-Dawley rats. Rat behavior was evaluated at 5, 24, and 48 hours after the appliance was set. Behavior was assessed in a test field by the number of lines crossed in the first 30 seconds and 5 minutes following force application; number of lines crossed to the center; rearing time; and facial grooming time. Experimental group 1 received intraperitoneal administration of 30 mg/kg celecoxib before every behavioral test. Experimental group 2 received 90 mg/kg before the first behavioral test, and physiologic saline was administered before the remaining behavioral tests. Control groups received saline before every behavioral test and were given passive (passive control group) and active (active control group) appliances, respectively. Parameters related to pain increased in the active controls, whereas the parameters in the experimental groups decreased to the level seen in the passive controls. Statistically significant differences in pain-related behavior between control and experimental groups were found at 5 and 24 hours after placing the appliance. Stress-related behavior was significantly less in the experimental groups compared to the active control group during experimental periods. The administration of celecoxib relieves pain- and stress-related behavior evoked by orthodontic tooth movement in the rat. This model might be a useful tool for the evaluation of pain and stress.

  4. Experimental muscle pain decreases the frequency threshold of electrically elicited muscle cramps.

    PubMed

    Serrao, Mariano; Arendt-Nielsen, Lars; Ge, Hong-You; Pierelli, Francesco; Sandrini, Giorgio; Farina, Dario

    2007-09-01

    This study in humans tested the hypothesis that nociceptive muscle afferent input facilitates the occurrence of muscle cramps. In 13 healthy adults, muscle cramps were experimentally induced in the foot by stimulating the tibialis posterior nerve at the ankle with 2-s bursts of stimuli separated by 30 s, with stimulation frequency increasing by 2-Hz increments from 10 Hz until the cramp appeared. The minimum stimulation frequency that induced the cramp was defined "cramp frequency threshold". In 2 days, elicitation of the cramp was performed in the two-feet with and without (baseline condition) injection of hypertonic (painful condition) or isotonic (control condition) saline into the deep midportion of the flexor hallucis brevis muscle, from where surface EMG signals were recorded. The cramp frequency threshold was lower for the painful condition with respect to its baseline (mean +/- SE, hypertonic saline: 25.7 +/- 2.1 Hz, corresponding baseline: 31.2 +/- 2.8 Hz; P < 0.01) while there was no difference between the threshold with isotonic injection with respect to baseline. EMG average rectified value and power spectral frequency were higher during the cramp than immediately before the stimulation that elicited the cramp (pre-cramp: 13.9 +/- 1.6 muV and 75.4 +/- 3.8 Hz, respectively; post-cramp: 19.9 +/- 3.2 muV and 101.6 +/- 6.0 Hz; P < 0.05). The results suggest that nociceptive muscle afferent activity induced by injection of hypertonic saline facilitates the generation of electrically elicited muscle cramps.

  5. Chenopodium ambrosioides L. Reduces Synovial Inflammation and Pain in Experimental Osteoarthritis

    PubMed Central

    Calado, Gustavo P.; Lopes, Alberto Jorge O.; Costa Junior, Livio M.; Lima, Francisco das Chagas A.; Silva, Lucilene A.; Pereira, Wanderson S.; do Amaral, Flávia M. M.; Garcia, João Batista S.; Cartágenes, Maria do Socorro de S.; Nascimento, Flávia R. F.

    2015-01-01

    The chronicity of osteoarthritis (OA), characterized by pain and inflammation in the joints, is linked to a glutamate receptor, N-methyl-D-aspartate (NMDA). The use of plant species such as Chenopodium ambrosioides L. (Amaranthaceae) as NMDA antagonists offers a promising perspective. This work aims to analyze the antinociceptive and anti-inflammatory responses of the crude hydroalcoholic extract (HCE) of C. ambrosioides leaves in an experimental OA model. Wistar rats were separated into six groups (n = 24): clean (C), negative control (CTL-), positive control (CTL+), HCE0.5, HCE5 and HCE50. The first group received no intervention. The other groups received an intra-articular injection of sodium monoiodoacetate (MIA) (8 mg/kg) on day 0. After six hours, they were orally treated with saline, Maxicam plus (meloxicam + chondroitin sulfate) and HCE at doses of 0.5 mg/kg, 5 mg/kg and 50 mg/kg, respectively. After three, seven and ten days, clinical evaluations were performed (knee diameter, mechanical allodynia, mechanical hyperalgesia and motor activity). On the tenth day, after euthanasia, synovial fluid and draining lymph node were collected for cellular quantification, and cartilage was collected for histopathological analysis. Finally, molecular docking was performed to evaluate the compatibility of ascaridole, a monoterpene found in HCE, with the NMDA receptor. After the third day, HCE reduced knee edema. HCE5 showed less cellular infiltrate in the cartilage and synovium and lower intensities of allodynia from the third day and of hyperalgesia from the seventh day up to the last treatment day. The HCE5 and HCE50 groups improved in forced walking. In relation to molecular docking, ascaridole showed NMDA receptor binding affinity. C. ambrosioides HCE was effective in the treatment of OA because it reduced synovial inflammation and behavioral changes due to pain. This effect may be related to the antagonistic effect of ascaridole on the NMDA receptor. PMID:26524084

  6. Chenopodium ambrosioides L. Reduces Synovial Inflammation and Pain in Experimental Osteoarthritis.

    PubMed

    Calado, Gustavo P; Lopes, Alberto Jorge O; Costa Junior, Livio M; Lima, Francisco das Chagas A; Silva, Lucilene A; Pereira, Wanderson S; Amaral, Flávia M M do; Garcia, João Batista S; Cartágenes, Maria do Socorro de S; Nascimento, Flávia R F

    2015-01-01

    The chronicity of osteoarthritis (OA), characterized by pain and inflammation in the joints, is linked to a glutamate receptor, N-methyl-D-aspartate (NMDA). The use of plant species such as Chenopodium ambrosioides L. (Amaranthaceae) as NMDA antagonists offers a promising perspective. This work aims to analyze the antinociceptive and anti-inflammatory responses of the crude hydroalcoholic extract (HCE) of C. ambrosioides leaves in an experimental OA model. Wistar rats were separated into six groups (n = 24): clean (C), negative control (CTL-), positive control (CTL+), HCE0.5, HCE5 and HCE50. The first group received no intervention. The other groups received an intra-articular injection of sodium monoiodoacetate (MIA) (8 mg/kg) on day 0. After six hours, they were orally treated with saline, Maxicam plus (meloxicam + chondroitin sulfate) and HCE at doses of 0.5 mg/kg, 5 mg/kg and 50 mg/kg, respectively. After three, seven and ten days, clinical evaluations were performed (knee diameter, mechanical allodynia, mechanical hyperalgesia and motor activity). On the tenth day, after euthanasia, synovial fluid and draining lymph node were collected for cellular quantification, and cartilage was collected for histopathological analysis. Finally, molecular docking was performed to evaluate the compatibility of ascaridole, a monoterpene found in HCE, with the NMDA receptor. After the third day, HCE reduced knee edema. HCE5 showed less cellular infiltrate in the cartilage and synovium and lower intensities of allodynia from the third day and of hyperalgesia from the seventh day up to the last treatment day. The HCE5 and HCE50 groups improved in forced walking. In relation to molecular docking, ascaridole showed NMDA receptor binding affinity. C. ambrosioides HCE was effective in the treatment of OA because it reduced synovial inflammation and behavioral changes due to pain. This effect may be related to the antagonistic effect of ascaridole on the NMDA receptor.

  7. Experimental muscle pain produces central modulation of proprioceptive signals arising from jaw muscle spindles.

    PubMed

    Capra, N F; Ro, J Y

    2000-05-01

    The aim of the present study was to investigate the effects of intramuscular injection with hypertonic saline, a well-established experimental model for muscle pain, on central processing of proprioceptive input from jaw muscle spindle afferents. Fifty-seven cells were recorded from the medial edge of the subnucleus interpolaris (Vi) and the adjacent parvicellular reticular formation from 11 adult cats. These cells were characterized as central units receiving jaw muscle spindle input based on their responses to electrical stimulation of the masseter nerve, muscle palpation and jaw stretch. Forty-five cells, which were successfully tested with 5% hypertonic saline, were categorized as either dynamic-static (DS) (n=25) or static (S) (n=20) neurons based on their responses to different speeds and amplitudes of jaw movement. Seventy-six percent of the cells tested with an ipsilateral injection of hypertonic saline showed a significant modulation of mean firing rates (MFRs) during opening and/or holding phases. The most remarkable saline-induced change was a significant reduction of MFR during the hold phase in S units (100%, 18/18 modulated). Sixty-nine percent of the DS units (11/16 modulated) also showed significant changes in MFRs limited to the hold phase. However, in the DS neurons, the MFRs increased in seven units and decreased in four units. Finally, five DS neurons showed significant changes of MFRs during both opening and holding phases. Injections of isotonic saline into the ipsilateral masseter muscle had little effect, but hypertonic saline injections made into the contralateral masseter muscle produced similar results to ipsilateral injections with hypertonic saline. These results unequivocally demonstrate that intramuscular injection with an algesic substance, sufficient to produce muscle pain, produces significant changes in the proprioceptive properties of the jaw movement-related neurons. Potential mechanisms involved in saline-induced changes in the

  8. The effect of Reiki on pain and anxiety in women with abdominal hysterectomies: a quasi-experimental pilot study.

    PubMed

    Vitale, Anne T; O'Connor, Priscilla C

    2006-01-01

    The purpose of this pilot study was to compare reports of pain and levels of state anxiety in 2 groups of women after abdominal hysterectomy. A quasi-experimental design was used in which the experimental group (n = 10) received traditional nursing care plus three 30-minute sessions of Reiki, while the control group (n = 12) received traditional nursing care. The results indicated that the experimental group reported less pain and requested fewer analgesics than the control group. Also, the experimental group reported less state anxiety than the control group on discharge at 72 hours postoperation. The authors recommend replication of this study with a similar population, such as women who require nonemergency cesarian section deliveries.

  9. Reduced habituation to experimental pain in migraine patients: a CO(2) laser evoked potential study.

    PubMed

    Valeriani, M; de Tommaso, M; Restuccia, D; Le Pera, D; Guido, M; Iannetti, G D; Libro, G; Truini, A; Di Trapani, G; Puca, F; Tonali, P; Cruccu, G

    2003-09-01

    The habituation to sensory stimuli of different modalities is reduced in migraine patients. However, the habituation to pain has never been evaluated. Our aim was to assess the nociceptive pathway function and the habituation to experimental pain in patients with migraine. Scalp potentials were evoked by CO(2) laser stimulation (laser evoked potentials, LEPs) of the hand and facial skin in 24 patients with migraine without aura (MO), 19 patients with chronic tension-type headache (CTTH), and 28 control subjects (CS). The habituation was studied by measuring the changes of LEP amplitudes across three consecutive repetitions of 30 trials each (the repetitions lasted 5 min and were separated by 5-min intervals). The slope of the regression line between LEP amplitude and number of repetitions was taken as an index of habituation. The LEPs consisted of middle-latency, low-amplitude responses (N1, contralateral temporal region, and P1, frontal region) followed by a late, high-amplitude, negative-positive complex (N2/P2, vertex). The latency and amplitude of these responses were similar in both patients and controls. While CS and CTTH patients showed a significant habituation of the N2/P2 response, in MO patients this LEP component did not develop any habituation at all after face stimulation and showed a significantly lower habituation than in CS after hand stimulation. The habituation index of the vertex N2/P2 complex exceeded the normal limits in 13 out of the 24 MO patients and in none of the 19 CTTH patients (P<0.0001; Fisher's exact test). Moreover, while the N1-P1 amplitude showed a significant habituation in CS after hand stimulation, it did not change across repetitions in MO patients. In conclusion, no functional impairment of the nociceptive pathways, including the trigeminal pathways, was found in either MO or CTTH patients. But patients with migraine had a reduced habituation, which probably reflects an abnormal excitability of the cortical areas involved in

  10. A cuckoo search algorithm for multimodal optimization.

    PubMed

    Cuevas, Erik; Reyna-Orta, Adolfo

    2014-01-01

    Interest in multimodal optimization is expanding rapidly, since many practical engineering problems demand the localization of multiple optima within a search space. On the other hand, the cuckoo search (CS) algorithm is a simple and effective global optimization algorithm which can not be directly applied to solve multimodal optimization problems. This paper proposes a new multimodal optimization algorithm called the multimodal cuckoo search (MCS). Under MCS, the original CS is enhanced with multimodal capacities by means of (1) the incorporation of a memory mechanism to efficiently register potential local optima according to their fitness value and the distance to other potential solutions, (2) the modification of the original CS individual selection strategy to accelerate the detection process of new local minima, and (3) the inclusion of a depuration procedure to cyclically eliminate duplicated memory elements. The performance of the proposed approach is compared to several state-of-the-art multimodal optimization algorithms considering a benchmark suite of fourteen multimodal problems. Experimental results indicate that the proposed strategy is capable of providing better and even a more consistent performance over existing well-known multimodal algorithms for the majority of test problems yet avoiding any serious computational deterioration.

  11. A Cuckoo Search Algorithm for Multimodal Optimization

    PubMed Central

    2014-01-01

    Interest in multimodal optimization is expanding rapidly, since many practical engineering problems demand the localization of multiple optima within a search space. On the other hand, the cuckoo search (CS) algorithm is a simple and effective global optimization algorithm which can not be directly applied to solve multimodal optimization problems. This paper proposes a new multimodal optimization algorithm called the multimodal cuckoo search (MCS). Under MCS, the original CS is enhanced with multimodal capacities by means of (1) the incorporation of a memory mechanism to efficiently register potential local optima according to their fitness value and the distance to other potential solutions, (2) the modification of the original CS individual selection strategy to accelerate the detection process of new local minima, and (3) the inclusion of a depuration procedure to cyclically eliminate duplicated memory elements. The performance of the proposed approach is compared to several state-of-the-art multimodal optimization algorithms considering a benchmark suite of fourteen multimodal problems. Experimental results indicate that the proposed strategy is capable of providing better and even a more consistent performance over existing well-known multimodal algorithms for the majority of test problems yet avoiding any serious computational deterioration. PMID:25147850

  12. Effect of experimental stress in 2 different pain conditions affecting the facial muscles.

    PubMed

    Woda, Alain; L'heveder, Gildas; Ouchchane, Lemlih; Bodéré, Céline

    2013-05-01

    Chronic facial muscle pain is a common feature in both fibromyalgia (FM) and myofascial (MF) pain conditions. In this controlled study, a possible difference in the mode of deregulation of the physiological response to a stressing stimulus was explored by applying an acute mental stress to FM and MF patients and to controls. The effects of the stress test were observed on pain, sympathetic variables, and both tonic and reflex electromyographic activities of masseteric and temporal muscles. The statistical analyses were performed through a generalized linear model including mixed effects. Painful reaction to the stressor was stronger (P < .001) and longer (P = .011) in FM than in MF independently of a higher pain level at baseline. The stress-induced autonomic changes only seen in FM patients did not reach significance. The electromyographic responses to the stress test were strongest for controls and weakest for FM. The stress test had no effect on reflex activity (area under the curve [AUC]) or latency, although AUC was high in FM and latencies were low in both pain groups. It is suggested that FM is characterized by a lower ability to adapt to acute stress than MF. This study showed that an acute psychosocial stress triggered several changes in 2 pain conditions including an increase in pain of larger amplitude in FM than in MF pain. Similar stress-induced changes should be explored as possible mechanisms for differentiation between dysfunctional pain conditions. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

  13. Effectiveness of Self-Hypnosis on the Relief of Experimental Dental Pain: A Randomized Trial.

    PubMed

    Wolf, Thomas Gerhard; Wolf, Dominik; Below, Dagna; d'Hoedt, Bernd; Willershausen, Brita; Daubländer, Monika

    2016-01-01

    This randomized, controlled clinical trial evaluates the effectiveness of self-hypnosis on pain perception. Pain thresholds were measured, and a targeted, standardized pain stimulus was created by electrical stimulation of the dental pulp of an upper anterior tooth. Pain stimulus was rated by a visual analogue scale (VAS). The pain threshold under self-hypnosis was higher (57.1 ± 17.1) than without hypnotic intervention (39.5 ± 11.8) (p < .001). Pain was rated lower on the VAS with self-hypnosis (4.0 ± 3.8) than in the basal condition without self-hypnosis (7.1 ± 2.7) (p < .001). Self-hypnosis can be used in clinical practice as an adjunct to the gold standard of local anesthesia for pain management, as well as an alternative in individual cases.

  14. Exostosis Bursata – Multimodality Imaging Approach

    PubMed Central

    Sharma, Praveen; Rege, Rujuta; Seena, CR; Rajesh, Saveetha

    2016-01-01

    Osteochondromas or exostosis are common benign bone tumours, commonly arising from the metaphyseal region of long bones (femur, humerus, tibia). Osteochondroma of the scapula are rare and cause mechanical irritation leading to bursal formation. We hereby report a case of 30-year-old man who presented with painful chest wall swelling and its multimodality approach to establish the diagnosis. PMID:27790547

  15. Increased COX2 in the trigeminal nucleus caudalis is involved in orofacial pain induced by experimental tooth movement.

    PubMed

    Gao, Yuan; Duan, Yin-Zhong

    2010-03-01

    Pain is among the major problems during orthodontic treatment. Recent studies have shown that central Cyclooxygenase2 (COX2) pathway was involved in several pain models. The present study investigated whether inducible COX2 within the trigeminal nucleus caudalis (Vc) contributed to experimental tooth movement pain in freely moving rats. Elastic rubber bands were inserted between the first and second maxillary molars bilaterally to establish tooth movement model. The directed mouth wiping behavior was used to evaluate the pain during tooth movement. COX2 distribution in Vc was studied by immunohistochemistry and the changes of COX2 expression were detected by Western blot at different time point after rubber band insertion. Our results showed that tooth movement significantly increased COX2 expression in Vc and the time spent on mouth wiping, reaching a maximum at 1 day and then decreasing gradually. Furthermore, the rhythm change of COX2 expression in Vc and the mouth wiping behavior were much correlative with each other. All of the COX2-immunoreactive structures in Vc exhibited NeuN-immunopositive staining and most of these COX2-immunoreactive neurons were Fos-immunopositive. Importantly, the mouth wiping behavior could be attenuated by intracisternal injection of NS-398 (a selective COX2 inhibitor) but not by periodontal administration of NS-398. All these results suggested that increased COX2 in Vc was involved in tooth movement pain and thus may be a central target for orthodontic pain treatment.

  16. Brain Network Response to Acupuncture Stimuli in Experimental Acute Low Back Pain: An fMRI Study.

    PubMed

    Shi, Yu; Liu, Ziping; Zhang, Shanshan; Li, Qiang; Guo, Shigui; Yang, Jiangming; Wu, Wen

    2015-01-01

    Most neuroimaging studies have demonstrated that acupuncture can significantly modulate brain activation patterns in healthy subjects, while only a few studies have examined clinical pain. In the current study, we combined an experimental acute low back pain (ALBP) model and functional magnetic resonance imaging (fMRI) to explore the neural mechanisms of acupuncture analgesia. All ALBP subjects first underwent two resting state fMRI scans at baseline and during a painful episode and then underwent two additional fMRI scans, once during acupuncture stimulation (ACUP) and once during tactile stimulation (SHAM) pseudorandomly, at the BL40 acupoint. Our results showed that, compared with the baseline, the pain state had higher regional homogeneity (ReHo) values in the pain matrix, limbic system, and default mode network (DMN) and lower ReHo values in frontal gyrus and temporal gyrus; compared with the OFF status, ACUP yielded broad deactivation in subjects, including nearly all of the limbic system, pain status, and DMN, and also evoked numerous activations in the attentional and somatosensory systems; compared with SHAM, we found that ACUP induced more deactivations and fewer activations in the subjects. Multiple brain networks play crucial roles in acupuncture analgesia, suggesting that ACUP exceeds a somatosensory-guided mind-body therapy for ALBP.

  17. A New Method for Sham-Controlled Acupuncture in Experimental Visceral Pain - a Randomized, Single-Blinded Study.

    PubMed

    Juel, Jacob; Liguori, Stefano; Liguori, Aldo; Valeriani, Massimiliano; Graversen, Carina; Olesen, Søren S; Drewes, Asbjørn M

    2016-07-01

    Acupuncture is increasingly used as an alternative to medical therapy for various pain conditions. To study the effect of acupuncture in experimental and clinical studies, a control condition with sham acupuncture is needed. However, as such models have not been established in assessment of acupunctures effect against visceral pain, this study aimed to validate a new method for blinded sham acupuncture in experimental rectal pain. Fifteen subjects underwent a sequence of either sham or real acupuncture in randomized order. In the sham arm, a hollow inner tube with a sharp tip was fitted into an outer tube and subjects were blinded to the stimulations. Before and after the intervention, pain was induced by rectal stimulation with an inflatable balloon distended until the subjects' pain threshold was reached. The resting electroencephalogram (EEG) was quantified by spectral power analysis to explore the central nervous system effects objectively. Additionally, after the second study day, the subject was asked to indicate the sequence of interventions. A significant increase in rectal balloon volume w