901
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Haroun OM, Hietaharju A, Bizuneh E, Tesfaye F, Brandsma WJ, Haanpää M, Rice AS, Lockwood DN. Investigation of neuropathic pain in treated leprosy patients in Ethiopia: A cross-sectional study. Pain 2012; 153:1620-1624. [DOI: 10.1016/j.pain.2012.04.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 04/03/2012] [Accepted: 04/09/2012] [Indexed: 11/30/2022]
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902
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Chaparro LE, Wiffen PJ, Moore RA, Gilron I. Combination pharmacotherapy for the treatment of neuropathic pain in adults. Cochrane Database Syst Rev 2012; 2012:CD008943. [PMID: 22786518 PMCID: PMC6481651 DOI: 10.1002/14651858.cd008943.pub2] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
BACKGROUND Pharmacotherapy remains an important modality for the treatment of neuropathic pain. However, as monotherapy current drugs are associated with limited efficacy and dose-related side effects. Combining two or more different drugs may improve analgesic efficacy and, in some situations, reduce overall side effects (e.g. if synergistic interactions allow for dose reductions of combined drugs). OBJECTIVES This review evaluated the efficacy, tolerability and safety of various drug combinations for the treatment of neuropathic pain. SEARCH METHODS We identified randomised controlled trials (RCTs) of various drug combinations for neuropathic pain from CENTRAL, MEDLINE, EMBASE and handsearches of other reviews and trial registries. The most recent search was performed on 9 April 2012. SELECTION CRITERIA Double-blind, randomised studies comparing combinations of two or more drugs (systemic or topical) to placebo and/or at least one other comparator for the treatment of neuropathic pain. DATA COLLECTION AND ANALYSIS Data extracted from each study included: proportion of participants a) reporting ≥ 30% pain reduction from baseline OR ≥ moderate pain relief OR ≥ moderate global improvement; b) dropping out of the trial due to treatment-emergent adverse effects; c) reporting each specific adverse effect (e.g. sedation, dizziness) of ≥ moderate severity. The primary comparison of interest was between study drug(s) and one or both single-agent comparators. We combined studies if they evaluated the same drug class combination at roughly similar doses and durations of treatment. We used RevMan 5 to analyse data for binary outcomes. MAIN RESULTS We identified 21 eligible studies: four (578 participants) evaluated the combination of an opioid with gabapentin or pregabalin; two (77 participants) evaluated an opioid with a tricyclic antidepressant; one (56 participants) of gabapentin and nortriptyline; one (120 participants) of gabapentin and alpha-lipoic acid, three (90 participants) of fluphenazine with a tricyclic antidepressant; three (90 participants) of an N-methyl-D-aspartate (NMDA) blocker with an agent from a different drug class; five (604 participants) of various topical medications; one (313 participants) of tramadol with acetaminophen; and another one (44 participants) of a cholecystokinin blocker (L-365,260) with morphine. The majority of combinations evaluated to date involve drugs, each of which share some element of central nervous system (CNS) depression (e.g. sedation, cognitive dysfunction). This aspect of side effect overlap between the combined agents was often reflected in similar or higher dropout rates for the combination and may thus substantially limit the utility of such drug combinations. Meta-analysis was possible for only one comparison of only one combination, i.e. gabapentin + opioid versus gabapentin alone. This meta-analysis involving 386 participants from two studies demonstrated modest, yet statistically significant, superiority of a gabapentin + opioid combination over gabapentin alone. However, this combination also produced significantly more frequent side effect-related trial dropouts compared to gabapentin alone. AUTHORS' CONCLUSIONS Multiple, good-quality studies demonstrate superior efficacy of two-drug combinations. However, the number of available studies for any one specific combination, as well as other study factors (e.g. limited trial size and duration), preclude the recommendation of any one specific drug combination for neuropathic pain. Demonstration of combination benefits by several studies together with reports of widespread clinical polypharmacy for neuropathic pain surely provide a rationale for additional future rigorous evaluations. In order to properly identify specific drug combinations which provide superior efficacy and/or safety, we recommend that future neuropathic pain studies of two-drug combinations include comparisons with placebo and both single-agent components. Given the apparent adverse impact of combining agents with similar adverse effect profiles (e.g. CNS depression), the anticipated development and availability of non-sedating neuropathic pain agents could lead to the identification of more favourable analgesic drug combinations in which side effects are not compounded.
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903
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Grace PM, Hurley D, Barratt DT, Tsykin A, Watkins LR, Rolan PE, Hutchinson MR. Harnessing pain heterogeneity and RNA transcriptome to identify blood-based pain biomarkers: a novel correlational study design and bioinformatics approach in a graded chronic constriction injury model. J Neurochem 2012; 122:976-94. [PMID: 22697386 DOI: 10.1111/j.1471-4159.2012.07833.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A quantitative, peripherally accessible biomarker for neuropathic pain has great potential to improve clinical outcomes. Based on the premise that peripheral and central immunity contribute to neuropathic pain mechanisms, we hypothesized that biomarkers could be identified from the whole blood of adult male rats, by integrating graded chronic constriction injury (CCI), ipsilateral lumbar dorsal quadrant (iLDQ) and whole blood transcriptomes, and pathway analysis with pain behavior. Correlational bioinformatics identified a range of putative biomarker genes for allodynia intensity, many encoding for proteins with a recognized role in immune/nociceptive mechanisms. A selection of these genes was validated in a separate replication study. Pathway analysis of the iLDQ transcriptome identified Fcγ and Fcε signaling pathways, among others. This study is the first to employ the whole blood transcriptome to identify pain biomarker panels. The novel correlational bioinformatics, developed here, selected such putative biomarkers based on a correlation with pain behavior and formation of signaling pathways with iLDQ genes. Future studies may demonstrate the predictive ability of these biomarker genes across other models and additional variables.
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Affiliation(s)
- Peter M Grace
- Discipline of Pharmacology, School of Medical Sciences, University of Adelaide, Adelaide, Australia.
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904
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Neuropathic pain—From guidelines to clinical practice. Scand J Pain 2012. [DOI: 10.1016/j.sjpain.2012.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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905
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Akural E, Järvimäki V, Korhonen R, Kautiainen H, Haanpää M. Pulsed radiofrequency in peripheral posttraumatic neuropathic pain: A double blind sham controlled randomized clinical trial. Scand J Pain 2012; 3:127-131. [PMID: 29913831 DOI: 10.1016/j.sjpain.2012.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2011] [Accepted: 04/30/2012] [Indexed: 10/28/2022]
Abstract
Background and purpose Pulsed radiofrequency (PRF) is widely used for the treatment of chronic pain, although its mechanism of action is not known. The evidence of efficacy of PRF for neuropathic pain (NP) conditions is limited. A double-blind, randomized, sham-controlled parallel study was conducted to evaluate the efficacy and safety of PRF in the treatment of peripheral posttraumatic NP. Methods Forty-five patients with peripheral posttraumatic NP in their upper or lower limb were randomly assigned to receive PRF or sham treatment to the injured peripheral nerve (s) causing peripheral posttraumatic NP. Only patients whose pain intensity was at least 5 on numerical rating scale (NRS) 0-10 and who had suffered from their NP for at least 6 months were included. All patients had dynamic mechanical allodynia or pinprick hyperalgesia in their painful area. They had achieved temporary pain relief of at least 50% with a local nerve block performed at a previous visit. The primary efficacy variable was the difference in 3-day mean pain intensity score from the baseline to 3 months. Other variables included response defined as ≥30% reduction in mean pain intensity at 3 months compared to baseline, Neuropathic Pain Scale (NPS) results, health related quality of life (SF-36) and adverse effects. The skin was anesthetized with 1% lidocaine. A radiofrequency needle was introduced through the skin, and then guided to a SMK cannula (52, 100 or 144mm depending on the target nerve) with 4 or 5mm active tip (SMK-C5-4, SMK-C10-5, SMK-C15-5, Radionics®, Burlington, MA, USA). The nerve was located accurately by stimulating at 50 Hz (threshold <0.5 V). Sham treatment or PRF was applied for 120s 1-4 times at each treatment point (Radionics®, Burlington, MA, USA). The total treatment time was up to 8 min. Both patients and clinicians were blinded during the whole treatment and follow-up period. Results Forty-three patients were included in the analyses. There was no statistically significant difference between PRF and sham treatment for the primary outcome efficacy variable. Seven patients (3 in PRF group and 4 in sham treatment group) achieved ≥30% pain relief (difference between groups was not significant). There was no statistically significant difference in the NPS or any dimension of SF-36 between the treatments. Eighteen patients reported adverse effects. They were mild and did not necessitate any treatment. Transient pain was reported by 17 patients, local irritation by 5 patients and local inflammation by 1 patient. There was no significant difference between the groups in the presence of adverse effects. Conclusions PRF was well tolerated, but this study failed to show efficacy of PRF over sham treatment for peripheral posttraumatic NP. Implications Based on our results, we do not recommend PRF for peripheral posttraumatic NP. More research of the possible use of PRF for various pain conditions is needed to determine its role in the management of prolonged pains.
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Affiliation(s)
- Ethem Akural
- Department of Anesthesiology, Oulu University Hospital, Oulu, Finland.,Pain Clinic, Helsinki University Central Hospital, Helsinki, Finland
| | - Voitto Järvimäki
- Department of Anesthesiology, Oulu University Hospital, Oulu, Finland
| | - Raija Korhonen
- Department of Anesthesiology, Oulu University Hospital, Oulu, Finland
| | - Hannu Kautiainen
- Unit of Family Practice, Central Hospital Jyväskylä, Kuopio, Finland.,Unit of Primary Health Care, Kuopio University Hospital, Kuopio, Finland
| | - Maija Haanpää
- Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland.,Etera Mutual Pension Insurance Company, Kuopio, Finland
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906
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Gormsen L, Bach FW, Rosenberg R, Jensen TS. Differential pain modulation in patients with peripheral neuropathic pain and fibromyalgia. Scand J Pain 2012; 3:116-123. [DOI: 10.1016/j.sjpain.2012.01.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 01/30/2012] [Indexed: 10/28/2022]
Abstract
Abstract
Background
The definition of neuropathic pain has recently been changed by the International Association for the Study of Pain. This means that conditions such as fibromyalgia cannot, as sometimes discussed, be included in the neuropathic pain conditions. However, fibromyalgia and peripheral neuropathic pain share common clinical features such as spontaneous pain and hypersensitivity to external stimuli. Therefore, it is of interest to directly compare the conditions.
Material and methods
In this study we directly compared the pain modulation in neuropathic pain versus fibromyalgia by recording responses to a cold pressor test in 30 patients with peripheral neuropathic pain, 28 patients with fibromyalgia, and 26 pain-free age-and gender-matched healthy controls. Patients were asked to rate their spontaneous pain on a visual analog scale (VAS (0–100 mm) immediately before and immediately after the cold pressor test. Furthermore the duration (s) of extremity immersion in cold water was used as a measure of the pain tolerance threshold, and the perceived pain intensity at pain tolerance on the VAS was recorded on the extremity in the water after the cold pressor test. In addition, thermal (thermo tester) and mechanical stimuli (pressure algometer) were used to determine sensory detection, pain detection, and pain tolerance thresholds in different body parts. All sensory tests were done by the same examiner, in the same room, and with each subject in a supine position. The sequence of examinations was the following: (1) reaction time, (2) pressure thresholds, (3) thermal thresholds, and (4) cold pressor test. Reaction time was measured to ensure that psychomotoric inhibitions did not influence pain thresholds.
Results
Pain modulation induced by a cold pressor test reduced spontaneous pain by 40% on average in neuropathic pain patients, but increased spontaneous pain by 2.6% in fibromyalgia patients. This difference between fibromyalgia and neuropathic pain patients was significant (P < 0.002). Fibromyalgia patients withdrew their extremity from the cold water significantly earlier than neuropathic pain patients and healthy controls; however, they had a higher perceived pain intensity on the VAS than neuropathic pain patients and control subjects. Furthermore, neuropathic pain patients had a localized hypersensitivity to mechanical and thermal stimuli in the affected area of the body. In contrast, fibromyalgia patients displayed a general hypersensitivity to mechanical and thermal stimuli when the stimuli were rated by the VAS, and hypersensitivity to some of the sensory stimuli.
Conclusions
These findings are the first to suggest that a conditioning stimulus evoked by a cold pressor test reduced spontaneous ongoing pain in patients with peripheral neuropathic pain, but not in fibromyalgia patients when directly compared. The current study supports the notion that fibromyalgia and neuropathic pain are distinct pain conditions with separate sensory patterns and dysfunctions in pain-modulating networks. Fibromyalgia should therefore not, as sometimes discussed, be included in NP conditions.
Implications
On the basis of the findings, it is of interest to speculate on the underlying mechanisms. The results are consistent with the idea that peripheral neuropathic pain is primarily driven from damaged nerve endings in the periphery, while chronic fibromyalgia pain may be a central disorder with increased activity in pain-facilitating systems.
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Affiliation(s)
- Lise Gormsen
- Danish Pain Research Center , Aarhus University Hospital , Aarhus , Denmark
| | | | - Raben Rosenberg
- Center for Psychiatric Research , Aarhus University Hospital Risskov , Risskov , Denmark
| | - Troels S. Jensen
- Danish Pain Research Center , Aarhus University Hospital , Aarhus , Denmark
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907
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Kersten C, Cameron MG. Cetuximab alleviates neuropathic pain despite tumour progression. BMJ Case Rep 2012; 2012:bcr.12.2011.5374. [PMID: 22707700 DOI: 10.1136/bcr.12.2011.5374] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The authors present the case of a 68-year-old male patient with metastatic rectal cancer. A pelvic recurrence resulted in neuropathic pain, radiating down his left leg. The pain was resistant to standard treatments. However, after nearly 3 years of debilitating pain, the patient experienced dramatic relief just hours after an infusion of the antiepidermal growth factor receptor antibody cetuximab. The analgesic effect lasted for 10-12 days and was repeated roughly every 12 days for three and a half years. To test for placebo effect, the patient received (unknown to him) 20% of his usual cetuximab dose and experienced no pain relief. The dramatic analgesic effect was documented in clinical notes, medication lists and in numeric rating scales even while his cancer was in radiological progression. Mitogen-activated protein kinase (MAPK)-signalling is believed to be an important driver of neuropathic pain and therefore, the authors hypothesise a direct inhibition of MAPK-signalling by cetuximab in neuronal or glial cells.
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Affiliation(s)
- Christian Kersten
- Center for Cancer Treatment, Southern Norway Hospital Trust, Kristiansand, Norway.
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908
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Eaton MJ, Berrocal Y, Wolfe SQ, Widerström-Noga E. Review of the history and current status of cell-transplant approaches for the management of neuropathic pain. PAIN RESEARCH AND TREATMENT 2012; 2012:263972. [PMID: 22745903 PMCID: PMC3382629 DOI: 10.1155/2012/263972] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/08/2012] [Accepted: 04/09/2012] [Indexed: 11/18/2022]
Abstract
Treatment of sensory neuropathies, whether inherited or caused by trauma, the progress of diabetes, or other disease states, are among the most difficult problems in modern clinical practice. Cell therapy to release antinociceptive agents near the injured spinal cord would be the logical next step in the development of treatment modalities. But few clinical trials, especially for chronic pain, have tested the transplant of cells or a cell line to treat human disease. The history of the research and development of useful cell-transplant-based approaches offers an understanding of the advantages and problems associated with these technologies, but as an adjuvant or replacement for current pharmacological treatments, cell therapy is a likely near future clinical tool for improved health care.
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Affiliation(s)
- Mary J. Eaton
- Miami VA Health System Center, D806C, 1201 NW 16th Street, Miami, FL 33125, USA
| | - Yerko Berrocal
- Department of Cellular Biology and Pharmacology, Herbert Wertheim College of Medicine, Florida International University, Miami, FL 33199, USA
| | - Stacey Q. Wolfe
- Department of Neurosurgery, Tripler Army Medical Center, 1 Jarrett White Road, Honolulu, HI 96859, USA
| | - Eva Widerström-Noga
- Miami VA Health System Center, D806C, 1201 NW 16th Street, Miami, FL 33125, USA
- The Miami Project to Cure Paralysis, Miller School of Medicine at the University of Miami, Miami, FL 33136, USA
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909
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Petersen GL, Finnerup NB, Nørskov KN, Grosen K, Pilegaard HK, Benedetti F, Price DD, Jensen TS, Vase L. Placebo manipulations reduce hyperalgesia in neuropathic pain. Pain 2012; 153:1292-1300. [DOI: 10.1016/j.pain.2012.03.011] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2011] [Revised: 03/01/2012] [Accepted: 03/09/2012] [Indexed: 12/01/2022]
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910
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Abstract
BACKGROUND Antiepileptic drugs have been used in pain management since the 1960s; some have shown efficacy in treating different neuropathic pain conditions. Clonazepam, a benzodiazepine, is an established antiepileptic drug, but its place in the treatment of neuropathic pain is unclear. OBJECTIVES To assess the analgesic efficacy and adverse effects of the antiepileptic drug clonazepam in neuropathic pain and fibromyalgia. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 2). MEDLINE, and EMBASE to 28 February 2012, together with reference lists of retrieved papers and reviews, and ClinicalTrials.gov. SELECTION CRITERIA We planned to include randomised, double-blind studies of eight weeks duration or longer, comparing clonazepam with placebo or another active treatment in chronic neuropathic pain or fibromyalgia. DATA COLLECTION AND ANALYSIS Two review authors would independently extract data for efficacy and adverse events, and examine issues of study quality. MAIN RESULTS We did not identify any studies that satisfied the inclusion criteria. AUTHORS' CONCLUSIONS This review uncovered no evidence of sufficient quality to support the use of clonazepam in chronic neuropathic pain or fibromyalgia.
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Affiliation(s)
- Ruth Corrigan
- University of OxfordPain Research and Nuffield Department of Clinical Neurosciences (Nuffield Division of Anaesthetics)Churchill HospitalOxfordOxfordshireUKOX3 7LJ
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911
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Oaklander AL, Wilson PR, Moskovitz PA, Manning DC, Lubenow T, Levine JD, Harden NR, Galer BS, Cooper MS, Bruehl S, Broatch J, Berde C, Bennett GJ. Response to “A new definition of neuropathic pain”. Pain 2012; 153:934-935. [DOI: 10.1016/j.pain.2012.01.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 01/11/2012] [Indexed: 11/28/2022]
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912
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Response to letters by Oaklander et al. and Horowitz. Pain 2012. [DOI: 10.1016/j.pain.2012.01.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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913
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Abstract
BACKGROUND Milnacipran is a serotonin-norepinephrine reuptake inhibitor (SNRI) that is sometimes used to treat chronic neuropathic pain and fibromyalgia. OBJECTIVES To evaluate the analgesic efficacy and adverse effects of milnacipran in the management of chronic neuropathic pain or fibromyalgia. SEARCH METHODS We searched CENTRAL, MEDLINE, and EMBASE to 4th of January 2012, together with reference lists of retrieved papers and reviews. SELECTION CRITERIA We included randomised, double-blind studies of eight weeks duration or longer, comparing milnacipran with placebo or another active treatment in chronic neuropathic pain or fibromyalgia. DATA COLLECTION AND ANALYSIS We extracted efficacy and adverse event data, and two study authors examined issues of study quality independently. MAIN RESULTS Five studies (4138 participants) were included, all of which were placebo-controlled, involved participants with fibromyalgia, and used titration to a target dose of 100 mg or 200 mg milnacipran. There were no other active comparators or studies in other neuropathic pain conditions. Study quality was generally good, although the imputation method used in analyses of the primary outcomes could overestimate treatment effect.Both doses of milnacipran provided moderate levels of pain relief to about 40% of those treated, compared to 30% with placebo, giving a number needed to treat of 8 to 10. Adverse events were common in both milnacipran (87%) and placebo (78%) groups, but serious adverse events (< 2%) did not differ between groups. Nausea and constipation were the most common events showing the greatest difference between groups (number needed to treat for an additional harmful outcome of 7 and 13 respectively, compared with placebo).Withdrawals for any reason were more common with milnacipran than placebo, and more common with 200 mg than 100 mg (NNH of 23 and 8.8 respectively, compared with placebo). This was largely driven by adverse event withdrawals, where the NNH compared with placebo was 14 for 100 mg, and 7.0 for 200 mg). Withdrawals due to lack of efficacy were more common with milnacipran than placebo but did not differ between doses (number needed to treat to prevent an additional unwanted outcome of 45 and 41 respectively). AUTHORS' CONCLUSIONS The evidence available indicates that milnacipran 100 mg or 200 mg is effective for a minority in the treatment of pain due to fibromyalgia, providing moderate levels of pain relief (at least 30%) to about 40% of participants, compared with about 30% with placebo. There were insufficient data to assess substantial levels of pain relief (at least 50%), and the use of last observation carried forward imputation may overestimate drug efficacy. Milnacipran is associated with increased adverse events and adverse event withdrawals, which were significantly greater for the higher dose. There were no data for the use of milnacipran for other chronic neuropathic pain conditions.
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Affiliation(s)
- Sheena Derry
- Pain Research and Nuffield Department of Clinical Neurosciences (Nuffield Division of Anaesthetics), University of Oxford, Oxford,UK.
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914
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Finnerup NB, Baastrup C. Spinal Cord Injury Pain: Mechanisms and Management. Curr Pain Headache Rep 2012; 16:207-16. [PMID: 22392531 DOI: 10.1007/s11916-012-0259-x] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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915
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Involvement of calcitonin gene-related peptide and CCL2 production in CD40-mediated behavioral hypersensitivity in a model of neuropathic pain. ACTA ACUST UNITED AC 2012; 7:117-28. [PMID: 22377050 DOI: 10.1017/s1740925x12000026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The neuropeptide calcitonin gene-related peptide (CGRP) is known to play a pro-nociceptive role after peripheral nerve injury upon its release from primary afferent neurons in preclinical models of neuropathic pain. We previously demonstrated a critical role for spinal cord microglial CD40 in the development of spinal nerve L5 transection (L5Tx)-induced mechanical hypersensitivity. Herein, we investigated whether CGRP is involved in the CD40-mediated behavioral hypersensitivity. First, L5Tx was found to significantly induce CGRP expression in wild-type (WT) mice up to 14 days post-L5Tx. This increase in CGRP expression was reduced in CD40 knockout (KO) mice at day 14 post-L5Tx. Intrathecal injection of the CGRP antagonist CGRP8-37 significantly blocked L5Tx-induced mechanical hypersensitivity. In vitro, CGRP induced glial IL-6 and CCL2 production, and CD40 stimulation added to the effects of CGRP in neonatal glia. Further, there was decreased CCL2 production in CD40 KO mice compared to WT mice 21 days post-L5Tx. However, CGRP8-37 did not significantly affect spinal cord CCL2 production following L5Tx in WT mice. Altogether, these data suggest that CD40 contributes to the maintenance of behavioral hypersensitivity following peripheral nerve injury in part through two distinct pathways, the enhancement of CGRP expression and spinal cord CCL2 production.
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916
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von Hehn CA, Baron R, Woolf CJ. Deconstructing the neuropathic pain phenotype to reveal neural mechanisms. Neuron 2012; 73:638-52. [PMID: 22365541 PMCID: PMC3319438 DOI: 10.1016/j.neuron.2012.02.008] [Citation(s) in RCA: 582] [Impact Index Per Article: 48.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/06/2012] [Indexed: 01/01/2023]
Abstract
After nerve injury maladaptive changes can occur in injured sensory neurons and along the entire nociceptive pathway within the CNS, which may lead to spontaneous pain or pain hypersensitivity. The resulting neuropathic pain syndromes present as a complex combination of negative and positive symptoms, which vary enormously from individual to individual. This variation depends on a diversity of underlying pathophysiological changes resulting from the convergence of etiological, genotypic, and environmental factors. The pain phenotype can serve therefore, as a window on underlying pathophysiological neural mechanisms and as a guide for developing personalized pain medicine.
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Affiliation(s)
- Christian A von Hehn
- FM Kirby Neurobiology Center, Children's Hospital Boston, and Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
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917
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Andrade P, Visser-Vandewalle V, Del Rosario JS, Daemen MA, Buurman WA, Steinbusch HW, Hoogland G. The thalidomide analgesic effect is associated with differential TNF-α receptor expression in the dorsal horn of the spinal cord as studied in a rat model of neuropathic pain. Brain Res 2012; 1450:24-32. [PMID: 22425187 DOI: 10.1016/j.brainres.2012.02.033] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 01/29/2012] [Accepted: 02/14/2012] [Indexed: 01/30/2023]
Abstract
The proinflammatory cytokine tumor necrosis factor-α (TNF-α) is well recognized as a key player in nociceptive signaling. Yet, therapeutic capitalization of this knowledge requires a better understanding of how TNF receptors (TNFR) contribute to pain. To address this question, we studied TNFR expression in the chronic sciatic nerve constriction (CCI) model of neuropathic pain. CCI and sham operated rats received two subcutaneous injections (one immediately after surgery, the other on postoperative day 5) containing either saline, GABA-reuptake inhibitor (NO-711), insulin-like growth factor-1 (IGF-1), ZVAD or thalidomide. Mechanical (using von Frey filaments) and thermal hypersensitivity (Hargreaves test) were assessed preoperatively and weekly during the first four postoperative weeks. Spinal cord dorsal horn samples were collected from animals that were sacrificed at 2 weeks and 4 weeks after surgery, and analyzed for TNFR1 and TNFR2 mRNA levels by qPCR and protein levels by Western blot. Compared to saline, all applied drug treatments resulted in a faster recovery from mechanical and thermal hypersensitivity, yet in a potency order of thalidomide>ZVAD=IGF-1>NO-711. CCI resulted in increased TNFR1 and TNFR2 mRNA and protein levels in the ipsilateral dorsal horn. Thalidomide was the only treatment that attenuated these increases. Finally, animals that showed a poor behavioral recovery were characterized by a significantly higher TNFR1/TNFR2 mRNA ratio. These data show that differential expression of TNFR in the dorsal horn is associated with recovery from pain in this model and suggest that the analgesic effects of thalidomide may act via this mechanism.
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Affiliation(s)
- Pablo Andrade
- Department of Neuroscience, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands.
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918
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Abstract
BACKGROUND Antiepileptic drugs have been used in pain management since the 1960s; some seem to be especially useful for neuropathic pain. Lacosamide is an antiepileptic drug that has recently been investigated for neuropathic pain relief, although it failed to get approval for painful diabetic peripheral neuropathy from either the Food and Drug Administration or the European Medicines Agency. OBJECTIVES To evaluate the analgesic efficacy and adverse effects of lacosamide in the management of chronic neuropathic pain or fibromyalgia. SEARCH METHODS We searched the Cochrane Neuromuscular Disease Group Specialized Register (2011, Issue 4), CENTRAL (2011, Issue 3), MEDLINE (January 2000 to August 2011) and EMBASE (2000 to August 2011) without language restriction, together with reference lists of retrieved papers and reviews. SELECTION CRITERIA We included randomised, double-blind studies of eight weeks duration or longer, comparing lacosamide with placebo or another active treatment in chronic neuropathic pain or fibromyalgia. DATA COLLECTION AND ANALYSIS Two review authors independently extracted data for efficacy and adverse events and examined issues of study quality, including risk of bias assessments. Where possible, we calculated numbers needed to treat to benefit from dichotomous data for effectiveness, adverse events and study withdrawals. MAIN RESULTS We included six studies; five (1863 participants) in painful diabetic neuropathy (PDN) and one (159 participants) in fibromyalgia. All were placebo-controlled and titrated to a target dose of 200 mg, 400 mg or 600 mg lacosamide daily, given as a divided dose. Study reporting quality was generally good, although the imputation method of last observation carried forward used in analyses of the primary outcomes is known to known to impart major bias where, as here, adverse event withdrawal rates were high. This, together with small numbers of patients and events for most outcomes at most doses meant that most results were of low quality, with moderate quality evidence available for some efficacy outcomes for 400 mg lacosamide.There were too few data for analysis of the 200 mg dose for painful diabetic neuropathy or any dose for fibromyalgia.In painful diabetic neuropathy, lacosamide 400 mg provided statistically increased rates of achievement of "moderate" and "substantial" benefit (at least 30% and at least 50% reduction from baseline in patient-reported pain respectively) and the patient global impression of change outcome of "much or very much improved". In each case the extra proportion benefiting above placebo was about 10%, yielding numbers needed to treat to benefit compared with placebo of 10 to 12. For lacosamide 600 mg there was no consistent benefit over placebo.There was no significant difference between any dose of lacosamide and placebo for participants experiencing any adverse event or a serious adverse event, but adverse event withdrawals showed a significant dose response. The number needed to treat to harm for adverse event withdrawal was 11 for lacosamide 400 mg and 4 for the 600 mg dose. AUTHORS' CONCLUSIONS Lacosamide has limited efficacy in the treatment of peripheral diabetic neuropathy. Higher doses did not give consistently better efficacy, but were associated with significantly more adverse event withdrawals. Where adverse event withdrawals are high with active treatment compared with placebo and when last observation carried forward imputation is used, as in some of these studies, significant overestimation of treatment efficacy can result. It is likely, therefore, that lacosamide is without any useful benefit in treating neuropathic pain; any positive interpretation of the evidence should be made with caution if at all.
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Affiliation(s)
- Leslie Hearn
- University of OxfordPain Research and Nuffield Department of Clinical Neurosciences (Nuffield Division of Anaesthetics)Pain Research Unit, Churchill HospitalOxfordOxfordshireUKOX3 7LE
| | - Sheena Derry
- University of OxfordPain Research and Nuffield Department of Clinical Neurosciences (Nuffield Division of Anaesthetics)Pain Research Unit, Churchill HospitalOxfordOxfordshireUKOX3 7LE
| | - R Andrew Moore
- University of OxfordPain Research and Nuffield Department of Clinical Neurosciences (Nuffield Division of Anaesthetics)Pain Research Unit, Churchill HospitalOxfordOxfordshireUKOX3 7LE
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919
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Horowitz SH. Response to commentary: A new definition of neuropathic pain. Pain 2012; 153:935. [PMID: 22341564 DOI: 10.1016/j.pain.2012.01.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2011] [Accepted: 01/11/2012] [Indexed: 11/26/2022]
Affiliation(s)
- Steven H Horowitz
- Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA. Tel.: +1 617 724 3992; fax: +1 617 726 6991
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920
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Jnoff E, Christophe B, Collart P, Coloretti F, Debeuckelaere A, De Ryck M, Fuks B, Genicot C, Gillard M, Guyaux M, Price N, Vandergeten MC, Vermeiren C. Discovery of Selective Alpha2CAdrenergic Receptor Agonists. ChemMedChem 2012; 7:385-90. [DOI: 10.1002/cmdc.201100528] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Indexed: 11/09/2022]
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921
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Barrot M. Tests and models of nociception and pain in rodents. Neuroscience 2012; 211:39-50. [PMID: 22244975 DOI: 10.1016/j.neuroscience.2011.12.041] [Citation(s) in RCA: 311] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Revised: 12/19/2011] [Accepted: 12/20/2011] [Indexed: 12/31/2022]
Abstract
Nociception and pain is a large field of both neuroscience and medical research. Over time, various tests and models were developed in rodents to provide tools for fundamental and translational research on the topic. Tests using thermal, mechanical, and chemical stimuli, measures of hyperalgesia and allodynia, models of inflammatory or neuropathic pain, constitute a toolbox available to researchers. These tests and models allowed rapid progress on the anatomo-molecular basis of physiological and pathological pain, even though they have yet to translate into new analgesic drugs. More recently, a growing effort has been put forth trying to assess pain in rats or mice, rather than nociceptive reflexes, or at studying complex states affected by chronic pain. This aids to further improve the translational value of preclinical research in a field with balanced research efforts between fundamental research, preclinical work, and human studies. This review describes classical tests and models of nociception and pain in rodents. It also presents some recent and ongoing developments in nociceptive tests, recent trends for pain evaluation, and raises the question of the appropriateness between tests, models, and procedures.
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Affiliation(s)
- M Barrot
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Strasbourg, France.
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922
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Jensen TS. High prevalence of posttraumatic stress disorder (PTSD) and pain sensitization in two Scandinavian samples of patients referred for pain rehabilitation. Scand J Pain 2012; 3:38. [PMID: 29913767 DOI: 10.1016/j.sjpain.2011.11.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Troels Staehelin Jensen
- Department of Neurology & Danish Pain Research Center, Aarhus University Hospital, Build 1A, Norrebrogade 44, 8000 Aarhus C, Denmark
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923
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Bryce TN, Biering-Sørensen F, Finnerup NB, Cardenas DD, Defrin R, Lundeberg T, Norrbrink C, Richards JS, Siddall P, Stripling T, Treede RD, Waxman SG, Widerström-Noga E, Yezierski RP, Dijkers M. International Spinal Cord Injury Pain Classification: part I. Background and description. Spinal Cord 2011; 50:413-7. [DOI: 10.1038/sc.2011.156] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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