http://www.hindawi.com The latest articles from Hindawi Publishing Corporation © 2013 , Hindawi Publishing Corporation . All rights reserved. Thu, 09 May 2013 14:30:28 +0000 http://www.hindawi.com/isrn/pain/2013/196429/ Analgesics can be administered in combination with caffeine for improved analgesic effectiveness in a process known as synergism. The mechanisms by which these combinations produce synergism are not yet fully understood. The aim of this study was to analyze whether the administration of diclofenac combined with caffeine produced antinociceptive synergism and whether opioid mechanisms played a role in this event. The formalin model was used to evaluate the antinociception produced by the oral administration of diclofenac, caffeine, or their combination. Opioid involvement was analyzed through intracerebroventricular (i.c.v.) administration of naloxone followed by the oral administration of the study drugs. Diclofenac presented a dose-dependent effect, with a mean effective dose (ED50) of 6.7 mg/kg. Caffeine presented an analgesic effect with a 17–36% range. The combination of subeffective doses of each of the two drugs presented the greatest synergism with an effect of 57.7 ± 5.6%. The maximal antinociceptive effect was obtained with the combination of 10.0 mg/kg diclofenac and 1.0 mg/kg of caffeine, with an effect of 76.7 ± 5.6%. The i.c.v. administration of naloxone inhibited the effect of diclofenac, both separately and combined. In conclusion, caffeine produces antinociceptive synergism when administered in combination with diclofenac, and this synergism is partially mediated by opioid mechanisms at the central level. José María Flores-Ramos and M. Irene Díaz-Reval Copyright © 2013 José María Flores-Ramos and M. Irene Díaz-Reval. All rights reserved. Mon, 15 Apr 2013 16:25:52 +0000 http://www.hindawi.com/isrn/pain/2013/567175/ Chronic neck pain (CNP) is common and costly, and the effect of physiotherapeutic interventions on the condition is unclear. We reviewed the literature for evidence of effect of physiotherapy interventions on patients with CNP. Five bibliographic databases (MEDLINE, EMBASE, CINAHL, Cochrane Library, and PEDro) were systematically searched. Randomised, placebo and active-treatment-controlled trials including physiotherapy interventions for adults with CNP were selected. Data were extracted primary outcome was pain. Risk of bias was appraised. Effect of an intervention was assessed, weighted to risk of bias. 42 trials reporting on randomised comparisons of various physiotherapy interventions and control conditions were eligible for inclusion involving 3919 patients with CNP. Out of these, 23 were unclear or at high risk of bias, and their results were considered moderate- or low-quality evidence. Nineteen were at low risk of bias, and here eight trials found effect on pain of a physiotherapy intervention. Only exercise therapy, focusing on strength and endurance training, and multimodal physiotherapy, cognitive-behavioural interventions, massage, manipulations, laser therapy, and to some extent also TNS appear to have an effect on CNP. However, sufficient evidence for application of a specific physiotherapy modality or aiming at a specific patient subgroup is not available. Pia Damgaard, Else Marie Bartels, Inge Ris, Robin Christensen, and Birgit Juul-Kristensen Copyright © 2013 Pia Damgaard et al. All rights reserved. Sun, 07 Apr 2013 16:17:06 +0000 http://www.hindawi.com/isrn/pain/2013/792383/ Background. Acupuncture-like TENS (AL-TENS) is a treatment modality that can be used to temporarily reduce pain. However, there is no clear data in the literature regarding the specific duration of analgesia induced by AL-TENS. Objectives. To describe and quantify the duration and magnitude of AL-TENS analgesia on experimental heat pain in healthy subjects and verify if the duration or magnitude of analgesia induced by the AL-TENS was influenced by the duration of the application of the AL-TENS (15 versus 30 minutes). Methods. A repeated-measures, intrasubject randomized experimental design was used, where each participant was his/her own control. 22 healthy volunteers underwent heat pain stimulations with a contact thermode before (pretest) and after (posttest) AL-TENS application (15 and 30 minutes). Outcome measures included subjective pain during AL-TENS, duration, and magnitude of AL-TENS-induced analgesia. Results. Survival analysis showed that the median duration of AL-TENS analgesia was 10 minutes following the application of either 15 or 30 minutes of AL-TENS. The magnitude of analgesia following either application was comparable at all points in time ( values > 0.05) and ranged between −20% and −36% pain reduction. Conclusion. Only half of the participants still had heat-pain analgesia induced by the AL-TENS at 15 minutes postapplication. Yannick Tousignant-Laflamme, Marilyne Brochu, Cynthia Dupuis-Michaud, Catherine Pagé, Draga Popovic, and Marie-Eve Simard Copyright © 2013 Yannick Tousignant-Laflamme et al. All rights reserved. Thu, 04 Apr 2013 08:12:31 +0000 http://www.hindawi.com/isrn/pain/2013/315626/ The NMDA receptor is central in the generation and maintenance of chronic pain. This receptor has several sites of modulation. One is the glutamate recognition site that can be blocked by (±)-3-(2-carboxypiperazin-yl)propyl-1-phosphoric acid or (±)-CPP. We investigated whether the effect of glial inhibition produced by propentophylline (PPF) can be enhanced when combined with (±)-CPP. We used Sprague-Dawley rats with experimental monoarthritis, administering intrathecally the ED30 for both drugs (3.97 μg of (±)-CPP and 1.42 μg of PPF), since this combination produces an antinociceptive supra-additive effect when used in mechanical nociception (Randall-Selitto test). The combination of (±)-PPF and CPP produced an antinociceptive effect which was greater than that each drug alone as tested by both the C reflex and windup. We conclude that the antinociceptive effect of the combination of (±)-PPF and CPP possibly generates a supra additive interaction type in monoarthritic rats. Claudio Laurido, José L. Martínez, and Francisco Morales Copyright © 2013 Claudio Laurido et al. All rights reserved. Mon, 25 Feb 2013 14:00:02 +0000 http://www.hindawi.com/isrn/pain/2013/617698/ Background. The flexion relaxation ratio (FRR) has been suggested as a measure of muscular performance in patients with low back pain (LBP). The purpose of this study was to investigate whether the FRR was responsive to acute LBP produced from a delayed onset muscle soreness (DOMS) protocol. Methods. Fifty-one pain-free volunteers performed DOMS to induce LBP. Current pain intensity, trunk flexion range of motion (ROM), and passive straight leg raise (SLR) were measured at baseline, 24 and 48 hours after DOMS. Participants were categorized into pain groups based on reported current pain intensity. Changes in FRR, trunk flexion ROM, and SLR ROM were examined using two-way repeated measures analysis of variance. Results. Pain group was not found to have a significant effect on FRR ( = 0.054, ), nor were there any two-way interactions for changes in FRR. The pain group had decreased trunk flexion ROM compared to the minimal pain group ( = 7.21, ), but no decreases in SLR ROM ( = 3.51, ) over time. Interpretation. There were no differences in FRR based on reported pain intensity of LBP from a DOMS protocol. The responsiveness of FRR might be limited in patients with acute onset LBP of muscular origin. Maggie E. Horn and Mark D. Bishop Copyright © 2013 Maggie E. Horn and Mark D. Bishop. All rights reserved. Tue, 25 Dec 2012 18:21:34 +0000 http://www.hindawi.com/isrn/pain/2013/726891/ Recent studies demonstrate that glial glutamate transporter-1 (GLT-1) upregulation attenuates visceral nociception. The present work further characterized the effect of ceftriaxone- (CTX-) mediated GLT-1 upregulation on visceral hyperalgesia. Intrathecal pretreatment with dihydrokainate, a selective GLT-1 antagonist, produced a reversal of the antinociceptive response to bladder distension produced by CTX. The hyperalgesic response to urinary bladder distension caused by intravesicular acrolein was also attenuated by CTX treatment as was the enhanced time spent licking of abdominal area due to intravesicular acrolein. Bladder inflammation via cyclophosphamide injections enhanced the nociceptive to bladder distension; cohorts administered CTX and concomitant cyclophosphamide showed reduced hyperalgesic response. Cyclophosphamide-induced bladder hyperalgesia correlated with a significant 22% increase in GluR1 AMPA receptor subunit expression in the membrane fraction of the lumbosacral spinal cord, which was attenuated by CTX coadministration. Finally, neonatal colon insult-induced hyperalgesia caused by intracolonic mustard oil (2%) administration at P9 and P11 was attenuated by CTX. These studies suggest that GLT-1 upregulation (1) attenuates the hyperalgesia caused by bladder irritation/inflammation or by neonatal colonic insult, (2) acts at a spinal site, and (3) may produce antinociceptive effects by attenuating GluR1 membrane trafficking. These findings support further consideration of this FDA-approved drug to treat chronic pelvic pain syndromes. K. Roman, M. Yang, and Robert L. Stephens Jr. Copyright © 2013 K. Roman et al. All rights reserved. Sat, 01 Dec 2012 11:10:43 +0000 http://www.hindawi.com/isrn/pain/2013/401732/ Chronic pain and depression are two major causes of disability. Comorbidity decreases psychosocial and physical functioning while increasing economic burden. The prevailing belief that Hispanics somaticize depression may hinder the diagnostic process and, thus, may impact outcomes. The purpose of this study was to explore the relationships among depression and depressive symptoms (somatic or nonsomatic) and function in chronic pain sufferers residing along the USA-Mexico border. Like other studies, as level of depression increased, level of pain increased and level of functioning decreased. So much so that almost a quarter of the participants reported moderate-to-severe depression, and another quarter of the participants reported suicidal ideation independent of depression or treatment. Unlike other published reports, we used a sample of chronic pain patients who received individualized, multimodal pain treatment. Compared to our previous work in a similar population, pain intensity and suicidal ideation were lower in this study. A plausible explanation is the use of antidepressants as adjuvant treatment for pain. Regardless of gender or ethnicity, persons with chronic pain will disclose symptoms of depression when appropriate tools are used to collect the data. Implications for future research and clinical practice are discussed. Kristynia M. Robinson and Jose J. Monsivais Copyright © 2013 Kristynia M. Robinson and Jose J. Monsivais. All rights reserved. Wed, 28 Nov 2012 19:08:02 +0000 http://www.hindawi.com/isrn/pain/2013/452957/ Purpose. Methadone, a synthetic opioid agonist, is an effective alternative to strong opioids (morphine, hydromorphone, oxycodone, and buprenorphine) and is widely available as an oral formulation. Few data have been published so far on the use of intravenous (i.v.) methadone for the management of severe or refractory cancer pain. Methods. We followed 10 consecutives cancer patients with severe pain, treated with IV methadone. All had advanced disease and had already received strong opioids, some in association with ketamine. Pain was assessed at T0, T24 hours, and at the end of the treatment. Results. All patients benefited from the switch to IV methadone with a reduction of pain on VAS after 24 hours (median: 4/10; range 0–5) until the end of the treatment (all cases <3/10). The median starting dose was 100 mg/day (range 20–400) and the final dose remained stable with a median of 100 mg/day (range 27–700). The median duration of IV methadone was 11 days (range 2–59). No cardiac toxicity had been observed. Conclusions. IV methadone is an effective pain relieving alternative for the treatment of severe cancer pain, especially in refractory pain syndrome. Moreover, we did not observe any toxicity (neurological or cardiac) or any other major side effects and the treatment was overall well tolerated. More extensive comparative studies should be planned. D. Lossignol, I. Libert, B. Michel, C. Rousseau, and M. Obiols-Portis Copyright © 2013 D. Lossignol et al. All rights reserved. Wed, 28 Nov 2012 09:52:59 +0000 http://www.hindawi.com/isrn/pain/2013/204108/ Objectives. Our objective was to investigate the time course of the placebo effect of acupuncture on pain and the factors affecting the placebo effect. Methods. Previously we retrieved three-armed randomized acupuncture trials including sham and no-treatment groups which were published until October 2009. We searched electronic databases again to identify additional trials from October 2009 to December 2011. After a screening of trials, fifteen three-armed acupuncture trials for pain were included in the analysis. Standardized mean differences between the sham and no-treatment groups were calculated for placebo effect. We then plotted the magnitude of the placebo effect over time. Results. The placebo effect gradually has increased for 12 weeks with a standardized mean difference of 0.74 (95% CI: 0.54 to 0.94). Then it decreased after 12 weeks as time passed. When the placebo effects were compared for factors including methodological qualities, they were not affected by all factors, except patient blinding. Trials with sufficient patient blinding showed a larger placebo effect at 8 weeks than those with insufficient patient blinding (). Conclusion. The placebo effect of acupuncture showed a unique pattern, which was affected by insufficient patient blinding. Yun Hyung Koog and Won Young Jung Copyright © 2013 Yun Hyung Koog and Won Young Jung. All rights reserved. Wed, 28 Nov 2012 09:12:17 +0000 http://www.hindawi.com/isrn/pain/2013/469575/ Chronic pelvic pain (CPP) is defined as pain of at least 6 months’ duration that occurs in the lower abdomen or below the umbilicus and has resulted in functional or psychological disability or required intervention and treatment. Therapeutic interventions center around the treatment of CPP as a diagnosis in and of itself, and treatment of specific disorders that may be related to CPP. A multidisciplinary approach for diagnosis and treatment seems to be most effective for symptomatic relief. This paper reviews the evidence for such interventions as psychological treatments including the use of complementary and alternative medicine techniques for CPP in women. Unfortunately, finding the best evidence in this setting is difficult as only very few randomized controlled trials are available. A combination of treatments is usually required over time for the treatment of refractory CPP. The multifactorial nature of CPP needs to be discussed with the patient and a good rapport as well as a partnership needs to be developed to plan a management program with regular followup. Promotion of a multidisciplinary approach which includes complementary and alternative medicine techniques in managing CPP in women seems to yield the best results. Sara Paiva and Márcia Mendonça Carneiro Copyright © 2013 Sara Paiva and Márcia Mendonça Carneiro. All rights reserved.