Impact of Nervous System Hyperalgesia on Pain, Disability, and Quality of Life in Patients With Knee Osteoarthritis: A Controlled Analysis

Objective. Refractory, disabling pain associated with knee osteoarthritis (OA) is usually treated with total knee replacement. However, pain in these patients might be associated with central nervous sensitization rather than peripheral inflammation and injury. We evaluated the presence of hyperalgesia in patients scheduled for a total knee replacement due to knee osteoarthritis with refractory pain, and we assessed the impact of pressure pain threshold measurements (PPT) on pain, disability, and quality of life of these patients. Methods. Sixty-two female patients were compared with 22 age-matched healthy controls without reported pain for the last year. PPT was measured at the lower extremities subcutaneous dermatomes, over the vastus medialis, adductor longus, rectus femoris, vastus lateralis, tibialis anterior, peroneus longus, iliacus, quadratus lumborum and popliteus muscles and at the supraspinous ligaments from L1-L5, over the L5-S1 and S1-S2 sacral areas and at the pes anserinus bursae and patellar tendon. Results. Patients with knee OA had significantly lower PPT over all evaluated structures versus healthy control subjects (P < 0.001). Lower PPT values were correlated with higher pain intensity, higher disability scores, and with poorer quality of life, except for the role-emotional and general health status. Combined PPT values over the patellar tendon, at the S2 subcutaneous dermatome and at the adductor longus muscle were the best predictors for visual analog scale and Western Ontario and McMaster Universities Osteoarthritis Index pain scores. Conclusion. Patients with pain due to osteoarthritis who were scheduled for total knee replacement showed hyperalgesia of nervous system origin that negatively impacted pain, knee functional capacity, and most aspects of quality of life.

Non-pharmacological approach to neuropathic pain: the use of repetitive transcranial magnetic stimulation

Neuromodulation is the branch of neurophysiology related to the therapeutic effects of electrical stimulations of the nervous system. There are currently different practical applications of neuromodulation techniques for the treatment of various neurological disorders, such as deep brain stimulation for Parkinson`s disease and repetitive transcranial magnetic stimulation (rTMS) for major depression. An increasing number of studies have been devoted to the analgesic effects of rTMS in chronic pain patients. RTMS has been used either as a therapeutic tool per se, or as a preoperative test in patients undergoing epidural precentral gyrus stimulation. High-frequency rTMS (a parts per thousand yen5 Hz) is considered to be excitatory, while low-frequency stimulation (a parts per thousand currency sign1 Hz) is considered to exert an inhibitory effect over neuronal populations of the primary motor cortex. However, other parameters of stimulation may play a central role on its clinical effects such as the type of coil, its orientation over the scalp, and the total number of rTMS sessions performed. Experimental data from animals, healthy volunteers, and neuropathic pain patients have suggested that stimulation of the primary motor cortex by rTMS is able to activate brain regions implicated in the processing of the different aspects of chronic pain, and influence brain regions involved in the endogenous opioid system. Over twenty prospective randomized sham-controlled trials have studied the analgesic effects of rTMS on chronic pain. Most of the patients included in these trials had central or peripheral neuropathic pain. Although most studies used a single session of stimulation, recent studies have shown that the analgesic effects of rTMS may outlast the stimulation period for many days when repetitive sessions are performed. This opens the possibility to use rTMS as a therapeutic tool of its own in the armamentarium against neuropathic pain.

ONSET OF ELECTRICAL ACTIVITY OF PATELLAR STABILIZER MUSCLES IN SUBJECTS WITH PATELLOFEMORAL PAIN

Objective: To asses the onset (%) of patella stabilizer muscles during maximal isometric contraction exercises (MIC) in individuals with and without signs of patellofemoral pain syndrome (PFPS) in open (OKC) and closed (CKC) kinetic chain exercises, Method: Assessments were carried out on 22 women; ten with no complains of anterior knee pain, and 12 with PFPS signs during MIC in OKC and CKC with the knee flexed at 90 degrees. The onset of the electromyographic activity of the vastus mediallis obliquus (VMO), vastus lateralis obliquus (VLO) and vastus lateralis longus (VLL) was identified by means of an algorithm in the Myosystem Br 1 software. The statistical analysis used was Chi-Square test and student`s t test, which are both tests with a level of significance at 5%. Results: The VMO and VLO muscles presented a greater onset compared to the VLL during OKC exercises for both groups and for the PFPS group without CCF No differences were observed between the groups. Conclusion: CKC and OKC exercises seem to benefit the synchronism of the musculature that supposedly benefits the patella stabilizer musculature, and can be recommended in physiotherapeutic treatment programs.

Role of IL-18 in overt pain-like behaviour in mice

There are evidences that targeting IL-18 might be beneficial to inhibit inflammatory symptoms, including hypernociception (decrease in nociceptive threshold). The mechanism of IL-18 mechanical hypernociception depends on endothelin in rats and mice. However, the role of IL-18 in overt pain-like behaviour remains undetermined. Therefore, we addressed the role of IL-18 in writhing response induced by intraperitoneal (i.p.) injection of phenyl-p-benzoquinone (PBQ) and acetic acid in mice. Firstly, it was detected that PBQ and acetic acid i.p. injection induced a dose-dependent number of writhes in Balb/c mice. Subsequently, it was observed that the PBQ- but not the acetic acid-induced writhes were diminished in IL-18 deficient ((-/-)) mice. Therefore, considering that IFN-gamma, endothelin and prostanoids mediate IL-18-induced mechanical hypernociception, we also investigated the role of these mediators in the same model of writhing response in which IL-18 participates. It was noticed that PBQ-induced writhes were diminished in IFN-gamma(-/-) mice and by the treatment with bosentan (mixed enclothelin ETA/ETB receptor antagonist), BQ 123 (cyclo[DTrp-DAsp-Pro-DVal-Leu], selective enclothelin ETA receptor antagonist), BQ 788 (N-cys-2,6-dimethylpiperidinocarbonyl-L-methylleucyl-D-1 -methoxycarboyl-D-norleucine, selective endothelin ETB receptor antagonist) or indomethacin (cycloxigenase inhibitor). Thus, IL-18, IFN-gamma, endothelin acting on endothelin ETA and ETB receptors, and prostanoids mediate PBQ-induced writhing response in mice. To conclude, these results further advance the understanding of the physiopathology of overt pain-like behaviour, and suggest for the first time a role for IL-18 in writhing response in mice. (C) 2008 Elsevier B.V. All rights reserved.

Role of complement C5a in mechanical inflammatory hypernociceptio: potential use of C5a receptor antagonists to control inflammatory pain

particularly neutrophil chemoattraction. Herein, the role of C5a in the genesis of inflammatory hypernociception was investigated in rats and mice using the specific C5a receptor antagonist PMX53 (AcF-[OP(D-Cha)WR]). Experimental approach: Mechanical hypernociception was evaluated with a modification of the Randall-Selitto test in rats and electronic pressure meter paw test in mice. Cytokines were measured by ELISA and neutrophil migration was determined by myeloperoxidase activity. Key results: Local pretreatment of rats with PMX53 (60-180 mg per paw) inhibited zymosan-, carrageenan-, lipopolysaccharide (LPS)- and antigen-induced hypernociception. These effects were associated with C5a receptor blockade since PMX53 also inhibited the hypernociception induced by zymosan- activated serum and C5a but not by the direct-acting hypernociceptive mediators, prostaglandin E-2 and dopamine. Underlying the C5a hypernociceptive mechanisms, PMX53 did not alter the cytokine release induced by inflammatory stimuli. However, PMX53 inhibited cytokine-induced hypernociception. PMX53 also inhibited the recruitment of neutrophils induced by zymosan but not by carrageenan or LPS, indicating an involvement of neutrophils in the hypernociceptive effect of C5a. Furthermore, the C5a-induced hypernociception was reduced in neutrophil-depleted rats. Extending these findings in rats, blocking C5a receptors also reduced zymosan- induced joint hypernociception in mice. Conclusions and implications: These results suggest that C5a is an important inflammatory hypernociceptive mediator, acting by a mechanism independent of hypernociceptive cytokine release, but dependent on the presence of neutrophils. Therefore, we suggest that inhibiting the action of C5a has therapeutic potential in the control of inflammatory pain.

Quercetin Reduces Inflammatory Pain: Inhibition of Oxidative Stress and Cytokine Production

Quercetin (1) is known to have both antioxidant and antinociceptive effects. However, the mechanism involved in its antinociceptive effect is not fully elucidated. Cytokines and reactive oxygen species have been implicated in the cascade of events resulting in inflammatory pain. Therefore, we evaluated the antinociceptive mechanism of 1 focusing on the role of cytokines and Oxidative stress. Intraperitoneal and oral treatments with 1 dose-dependently inhibited inflammatory nociception induced by acetic acid and phenyl-p-benzoquinone and also the second phase of formalin- and carrageenin-induced mechanical hypernociception. Compound I also inhibited the hypernociception induced by cytokines (e.g., TNF alpha and CXCL1), but not by inflammatory mediators that directly sensitize the nociceptor such as PGE(2) and dopamine. On the other hand, 1 reduced carrageenin-induced IL-1 beta production as well as carrageenin-induced decrease of reduced glutathione (GSH) levels. These results suggest that I exerts its analgesic effect by inhibiting pro-nociceptive cytokine production and the oxidative imbalance mediation of inflammatory pain.

Comparison between the reliability levels of manual palpation and pressure pain threshold in children who reported orofacial pain

The aim of this study was to compare the intra-and inter-rater reliability of pressure pain threshold (PPT) and manual palpation (MP) of orofacial structures in symptomatic and symptom-free children for temporomandibular disorders (TMD). Fourteen children reporting pain in masticatory muscles or the temporomandibular joint and 16 symptom-free children were randomly assessed on three different occasions: by rater-1 in the first and third session and by rater-2 in the second session. The trained raters applied algometry and MP as recommended by the Research Diagnostic Criteria for TMD. Intraclass correlation coefficients and the Kappa statistic were used to assess the levels of reliability of PPT and MP, respectively. Excellent intra-and inter-rater reliability levels were observed for PPT values at most of the examined sites for symptom-free children and excellent and moderate reliability levels for children reporting pain. For MP, moderate and poor intra-rater and inter-rater reliability levels were observed for most sites in both groups. Algometry showed higher reliability levels for both groups of children and is recommended for pain assessment in children in association with MP. (C) 2010 Elsevier Ltd. All rights reserved.

Pain and distress reactivity and recovery as early predictors of temperament in toddlers born preterm

Background: Pain reactivity may reflect underlying mechanisms of constitutional aspects of temperament. Aim: To examine whether the neonatal biobehavioral reactivity and recovery responses from pain and distress, as well as the gestational age, the illness severity and the amount of painful procedures undergone the Neonatal Intensive Care Unit (NICU) stay, predict temperament later in toddlerhood, in vulnerable children born preterm. Study design: Prospective-longitudinal study. Subjects: Twenty-six preterm and very low birth weight infants followed from birth to toddlerhood. Outcome measures: Illness severity was assessed with the Clinical Risk Index for Babies (CRIB) score. The medical charts were reviewed prospectively for obtaining the amount of pain exposure in NICU. For assessing the behavioral and cardiac reactivity and recovery from pain and distress, the neonates were evaluated during routine blood collection in the NICU in the first 10 days of life. Pain and distress reactivity and recovery was measured using the Neonatal Facial Coding System score, the duration of crying. and the magnitude of average heart rate. At toddlerhood, mothers answered the Early Childhood Behavior Questionnaire. Results: Higher biobehavioral reactivity to pain and distress predicted higher temperamental Negative Affect, above and beyond gestational age, illness severity and amount of pain exposure in NICU. However, we did not find a predictive relation between gestational age, CRIB score and number of painful procedures undergone NICU and toddler`s temperament. Conclusions: The findings highlight the relevance of the neonatal individual characteristics of reactivity for identifying more vulnerable infants for future problems in biobehavioral regulation. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

Influence of the menstrual cycle on the pressure pain threshold of masticatory muscles in patients with masticatory myofascial pain

Objective. The aim of this study was to investigate the influence of the menstrual cycle and oral contraceptive (OC) intake on the pressure pain threshold (PPT) of masticatory muscles in patients with masticatory myofascial pain (MFP). Study design. The sample was composed of 36 women, divided into 4 groups, according to the presence of MFP and the intake of OC (15 patients had MFP [7 taking OC] and 21 were pain-free controls [8 taking OC]). The algometer-based PPT of masseter and temporalis, and the record of subjective pain by visual analog scale (VAS) were determined during 2 consecutives menstrual cycles at 4 phases (menstrual, follicular, periovulatory, and luteal). A 3-way ANOVA for repeated measurements, Kruskal-Wallis, Friedman, and Dunn tests, with a 5% significant level analyzed the data. Results. PPT was significantly lower in MFP patients when compared with controls throughout the experiment (P < .001). The menstrual phases did not influence PPT (P > .05), while the intake of OC seems to raise PPT levels for the left temporalis (P = .01) and right masseter (P = .04). VAS was, in general, higher at the menstrual phase Conclusions. Different phases of the menstrual cycle have no influence on PPT values, regardless of the presence of a previous condition, as masticatory myofascial pain, while the intake of OC is associated with decreased levels of reported pain.

Modification of induced ischaemic pain by placebo electrotherapy

Quantifying the analgesic effect of placebo electrotherapy is an important part of understanding the placebo response in physiotherapy. This repeated measures study of induced ischaemic pain compared reports of pain threshold, pain tolerance, and pain endurance under three conditions: control, placebo interferential, and placebo TENS. Both of the placebo conditions significantly delayed the report of pain threshold. Placebo interferential also delayed pain tolerance. Each placebo condition reduced pain intensity in the 6th minute. Only placebo TENS reduced pain at the 9th minute of ischaemic pain. The nature of pain reduction in the placebo conditions suggests that analgesia was due to learned expectancies and endogenous opioid release. Further research into the impact of positive expectancies of pain relief in our patients could clarify the efficacy of physiotherapy outcomes for pain.

Brazilian National School of Public Administration

The Brazilian National School of Public Administration (Escola Nacional de Administra????o P??blica ??? ENAP) is a public foundation linked to the Ministry of Planning, Budget and Management. Founded in 1986, its core mission is ???to develop competencies of civil servants in order to enhance government capacity for managing public policies???. To fulfill its mission, a wide program of learning and continued education is offered to public policy managers as well as e-learning and customized courses, in accordance to governmental and institutional strategic objectives. ENAP???s courses are framed according to governmental strategic demands for social inclusion, poverty reduction as well as economic development in order to strengthen the leading South American democracy. The range and diversity of its programs mirrors the challenges of deep changes in the jobs market and the work environment, faced by the current 550,000 federal civil servants and the over 7,000,000 state and municipal civil servants in Brazil, as last counted in 2006.

Evaluation of a program to reduce back pain in nursing personnel

OBJECTIVE: To evaluate the effectiveness of a program designed to reduce back pain in nursing aides. METHODS: Female nursing aides from a university hospital who had suffered episodes of back pain for at least six months were included in the study. Participants were randomly divided into a control group and an intervention group. The intervention program involved a set of exercises and an educational component stressing the ergonomic aspect, administered twice a week during working hours for four months. All subjects answered a structured questionnaire and the intensity of pain was assessed before and after the program using a visual analogue scale (VAS). Student's t-test or the Wilcoxon Rank Sum Test for independent samples, and Chi-square test or the Exact Fisher test for categorical analysis, were used. The McNemar test and the Wilcoxon matched pairs test were used to compare the periods before and after the program. RESULTS: There was a statistically significant decrease in the frequency of cervical pain in the last two months and in the last seven days in the intervention group. There was also a reduction in cervical pain intensity in the two periods (2 months, 7 days) and lumbar pain intensity in the last 7 days. CONCLUSIONS: The results suggest that a program of regular exercise with an emphasis on ergonomics can reduce musculoskeletal symptoms in nursing personnel.

Back pain in adults living in quilombola territories of Bahia, Northeastern Brazil

OBJECTIVE To analyze the factors associated with back pain in adults who live in quilombola territories. METHODS A population-based survey was performed on quilombola communities of Vitória da Conquista, state of Bahia, Northeastern Brazil. The sample (n = 750) was established via a raffle of residences. Semi-structured interviews were conducted to investigate sociodemographics and employment characteristics, lifestyle, and health conditions. The outcome was analyzed as a dichotomous variable (Poisson regression). RESULTS The prevalence of back pain was of 39.3%. Age ≥ 30 years and being a smoker were associated with the outcome. The employment status was not related to back pain. CONCLUSIONS The survey identified a high prevalence of back pain in adults. It is suggested to support the restructuring of the local public service in order to outline programs and access to healthy practices, assistance, diagnosis, and treatment of spine problems.

Relationship of cryptosporidiosis to abdominal pain and diarrhea in Mayan Indians

Demonstration of cryptosporidiosis in Mayan Indians living around Lake Atitlan provided an opportunity to correlate infection with abdominal pain and/or diarrhea in different age groups of children. 94 subjects experiencing abdominal pain and/or diarrhea, between the ages of 2 and 13 were studied in towns around Lake Atitlan, Guatemala, over a two-year period. Cryptosporidium oocysts were found in the feces of 29% of children who presented with abdominal pain and 21% with diarrhea. Of the 60 infected subjects, 45% were experiencing abdominal pain and 33% diarrhea, 22% had abdominal pain and diarrhea. Both abdominal pain and diarrhea were significantly higher in children under 10 years of age and were most prevalent in the 6-9 year old age group but the correlation of symptoms to infection was not significantly different as the ages of the children increased. The high frequency of abdominal pain and/or diarrhea with infection in children was consistent with cryptosporidiosis, a disease considered as one of several common intestinal infections that produce these symptoms.

Women's Attachment as a Predictor of Pain During Labour and Post-Delivery: a Prospective Observational Study

INTRODUCTION: Labour is considered to be one of the most painful and significant experiences in a woman's life. The aim of this study was to examine whether women's attachment style is a predictor of the pain experienced throughout labour and post-delivery. MATERIAL AND METHODS:Thirty-two pregnant women were assessed during the third trimester of pregnancy and during labour. Adult attachment was assessed with the Adult Attachment Scale ' Revised. The perceived intensity of labour pain was measured using a visual analogue scale for pain in the early stage of labour, throughout labour and post-delivery. RESULTS:Women with an insecure attachment style reported more pain at 3 cm of cervical dilatation (p < 0.05), before the administration of analgesia (p < 0.01) and post-delivery (p < 0.05) than those securely attached. In multivariate models, attachment style was a significant predictor of labour pain at 3 cm of cervical dilatation and before the first administration of analgesia but not of the perceived pain post-delivery. DISCUSSION: These findings confirm that labour pain is influenced by relevant psychological factors and suggest that a woman's attachment style may be a risk factor for greater pain during labour. CONCLUSION:Future studies in the context of obstetric pain may consider the attachment style as an indicator of individual differences in the pain response during labour. This may have important implications in anaesthesiology and to promote a relevant shift in institutional practices and therapeutic procedures.