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Augmented Pain Processing in Primary and Secondary Somatosensory Cortex in Fibromyalgia: A Magnetoencephalography Study Using Intra-Epidermal Electrical Stimulation. PLoS One 2016; 11:e0151776. [PMID: 26992095 PMCID: PMC4798786 DOI: 10.1371/journal.pone.0151776] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 03/03/2016] [Indexed: 11/19/2022] Open
Abstract
The aim of this study was to investigate augmented pain processing in the cortical somatosensory system in patients with fibromyalgia (FM). Cortical evoked responses were recorded in FM (n = 19) and healthy subjects (n = 21) using magnetoencephalography after noxious intra-epidermal electrical stimulation (IES) of the hand dorsum (pain rating 6 on a numeric rating scale, perceptually-equivalent). In addition, healthy subjects were stimulated using the amplitude corresponding to the average stimulus intensity rated 6 in patients with FM (intensity-equivalent). Quantitative sensory testing was performed on the hand dorsum or thenar muscle (neutral site) and over the trapezius muscle (tender point), using IES (thresholds, ratings, temporal summation of pain, stimulus-response curve) and mechanical stimuli (threshold, ratings). Increased amplitude of cortical responses was found in patients with FM as compared to healthy subjects. These included the contralateral primary (S1) and bilateral secondary somatosensory cortices (S2) in response to intensity-equivalent stimuli and the contralateral S1 and S2 in response to perceptually-equivalent stimuli. The amplitude of the contralateral S2 response in patients with FM was positively correlated with average pain intensity over the last week. Quantitative sensory testing results showed that patients with FM were more sensitive to painful IES as well as to mechanical stimulation, regardless of whether the stimulation site was the hand or the trapezius muscle. Interestingly, the slope of the stimulus-response relationship as well as temporal summation of pain in response to IES was not different between groups. Together, these results suggest that the observed pain augmentation in response to IES in patients with FM could be due to sensitization or disinhibition of the cortical somatosensory system. Since the S2 has been shown to play a role in higher-order functions, further studies are needed to clarify the role of augmented S2 response in clinical characteristics of FM.
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152
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Chan ACY, Wilder-Smith EP. Small fiber neuropathy: Getting bigger! Muscle Nerve 2016; 53:671-82. [PMID: 26872938 DOI: 10.1002/mus.25082] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2016] [Indexed: 12/13/2022]
Abstract
Etiological and clinical heterogeneity of small fiber neuropathy (SFN) precludes a unifying approach and necessitates reliance on recognizable clinical syndromes. Symptoms of SFN arise from dysfunction in nociception, temperature, and autonomic modalities. This review focuses on SFN involving nociception and temperature, examining epidemiology, etiology, clinical presentation, diagnosis, pathophysiology, and management. Prevalence of SFN is 52.95 per 100,000 population, and diabetes and idiopathic are the most common etiologies. Dysesthesia, allodynia, pain, burning, and coldness sensations frequently present in a length-dependent pattern. Additional autonomic features in gastrointestinal, urinary, or cardiovascular systems are frequent but poorly objectified. SFN is diagnosed by intraepidermal nerve fiber density and quantitative sensory and autonomic tests in combination with normal nerve conduction. Pathophysiological understanding centers on sodium channel dysfunction, and genetic forms are beginning to be understood. Treatment is directed at the underlying etiology supported by symptomatic treatment using antidepressants and anticonvulsants. Little is known about long-term outcomes, and systematic cohort studies are needed.
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Affiliation(s)
- Amanda C Y Chan
- Division of Neurology, National University Hospital, Level 10 Tower Block, University Medicine Cluster, 1E Kent Ridge Road, 119228, Singapore
| | - Einar P Wilder-Smith
- Division of Neurology, National University Hospital, Level 10 Tower Block, University Medicine Cluster, 1E Kent Ridge Road, 119228, Singapore.,Neurology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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153
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Wang SM, Han C, Lee SJ, Patkar AA, Masand PS, Pae CU. Fibromyalgia diagnosis: a review of the past, present and future. Expert Rev Neurother 2016; 15:667-79. [PMID: 26035624 DOI: 10.1586/14737175.2015.1046841] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Diagnosis of fibromyalgia (FM) remains controversial even though diverse diagnostic criteria have been developed. This review looks at the history, evolution of diagnostic criteria, endless controversy, recent trends and future perspectives regarding FM diagnosis. Some have criticized that diagnosis of FM could lead to medicalization, whereas others have raised concerns of under-diagnosing FM. With the evolution of diagnosis criteria from American College of Rheumatology 1990 to modified American College of Rheumatology 2010, diagnosis of FM has become simpler. The recent trend of applying patient-reported questionnaires has also increased a simpler FM diagnosis. Reliable biomarkers will not be available for the foreseeable future, so diverse assessment tools will have to be used more pro-actively. After initial diagnosis, multiple and comprehensive assessment measures are needed during the course of treatment in order to better understand type and severity of FM symptoms. These, in turn, could help classify FM based on symptom domain, symptom severity, and comorbidity which would enable more personalized treatment.
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Affiliation(s)
- Sheng-Min Wang
- Department of Psychiatry, The Catholic University of Korea College of Medicine, Seoul, Korea
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154
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155
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Tigerholm J, Petersson ME, Obreja O, Eberhardt E, Namer B, Weidner C, Lampert A, Carr RW, Schmelz M, Fransén E. C-fiber recovery cycle supernormality depends on ion concentration and ion channel permeability. Biophys J 2016; 108:1057-71. [PMID: 25762318 DOI: 10.1016/j.bpj.2014.12.034] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Revised: 11/30/2014] [Accepted: 12/17/2014] [Indexed: 12/20/2022] Open
Abstract
Following each action potential, C-fiber nociceptors undergo cyclical changes in excitability, including a period of superexcitability, before recovering their basal excitability state. The increase in superexcitability during this recovery cycle depends upon their immediate firing history of the axon, but also determines the instantaneous firing frequency that encodes pain intensity. To explore the mechanistic underpinnings of the recovery cycle phenomenon a biophysical model of a C-fiber has been developed. The model represents the spatial extent of the axon including its passive properties as well as ion channels and the Na/K-ATPase ion pump. Ionic concentrations were represented inside and outside the membrane. The model was able to replicate the typical transitions in excitability from subnormal to supernormal observed empirically following a conducted action potential. In the model, supernormality depended on the degree of conduction slowing which in turn depends upon the frequency of stimulation, in accordance with experimental findings. In particular, we show that activity-dependent conduction slowing is produced by the accumulation of intraaxonal sodium. We further show that the supernormal phase results from a reduced potassium current Kdr as a result of accumulation of periaxonal potassium in concert with a reduced influx of sodium through Nav1.7 relative to Nav1.8 current. This theoretical prediction was supported by data from an in vitro preparation of small rat dorsal root ganglion somata showing a reduction in the magnitude of tetrodotoxin-sensitive relative to tetrodotoxin -resistant whole cell current. Furthermore, our studies provide support for the role of depolarization in supernormality, as previously suggested, but we suggest that the basic mechanism depends on changes in ionic concentrations inside and outside the axon. The understanding of the mechanisms underlying repetitive discharges in recovery cycles may provide insight into mechanisms of spontaneous activity, which recently has been shown to correlate to a perceived level of pain.
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Affiliation(s)
- Jenny Tigerholm
- Department of Computational Biology, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden; Stockholm Brain Institute, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Marcus E Petersson
- Department of Computational Biology, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden; Stockholm Brain Institute, KTH Royal Institute of Technology, Stockholm, Sweden
| | - Otilia Obreja
- Anaesthesiology, Universitaetsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Esther Eberhardt
- Institute of Physiology and Pathophysiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Barbara Namer
- Department of Anesthesiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Christian Weidner
- Department of Anesthesiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Angelika Lampert
- Institute of Physiology and Pathophysiology, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany; Institute of Physiology, RWTH Aachen University, Aachen, Germany
| | - Richard W Carr
- Anaesthesiology, Universitaetsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Martin Schmelz
- Anaesthesiology, Universitaetsmedizin Mannheim, University of Heidelberg, Mannheim, Germany
| | - Erik Fransén
- Department of Computational Biology, School of Computer Science and Communication, KTH Royal Institute of Technology, Stockholm, Sweden; Stockholm Brain Institute, KTH Royal Institute of Technology, Stockholm, Sweden.
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156
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Oaklander AL. Immunotherapy Prospects for Painful Small-fiber Sensory Neuropathies and Ganglionopathies. Neurotherapeutics 2016; 13:108-17. [PMID: 26526686 PMCID: PMC4720682 DOI: 10.1007/s13311-015-0395-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The best-known peripheral neuropathies are those affecting the large, myelinated motor and sensory fibers. These have well-established immunological causes and therapies. Far less is known about the somatic and autonomic "small fibers"; the unmyelinated C-fibers, thinly myelinated A-deltas, and postganglionic sympathetics. The small fibers sense pain and itch, innervate internal organs and tissues, and modulate the inflammatory and immune responses. Symptoms of small-fiber neuropathy include chronic pain and itch, sensory impairment, edema, and skin color, temperature, and sweating changes. Small-fiber polyneuropathy (SFPN) also causes cardiovascular, gastrointestinal, and urological symptoms, the neurologic origin of which often remains unrecognized. Routine electrodiagnostic study does not detect SFPN, so skin biopsies immunolabeled to reveal axons are recommended for diagnostic confirmation. Preliminary evidence suggests that dysimmunity causes some cases of small-fiber neuropathy. Several autoimmune diseases, including Sjögren and celiac, are associated with painful small-fiber ganglionopathy and distal axonopathy, and some patients with "idiopathic" SFPN have evidence of organ-specific dysimmunity, including serological markers. Dysimmune SFPN first came into focus in children and teenagers as they lack other risk factors, for example diabetes or toxic exposures. In them, the rudimentary evidence suggests humoral rather than cellular mechanisms and complement consumption. Preliminary evidence supports efficacy of corticosteroids and immunoglobulins in carefully selected children and adult patients. This paper reviews the evidence of immune causality and the limited data regarding immunotherapy for small-fiber-predominant ganglionitis, regional neuropathy (complex regional pain syndrome), and distal SFPN. These demonstrate the need to develop case definitions and outcome metrics to improve diagnosis, enable prospective trials, and dissect the mechanisms of small-fiber neuropathy.
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Affiliation(s)
- Anne Louise Oaklander
- Department of Neurology and Department of Pathology (Neuropathology) Massachusetts General Hospital, Harvard Medical School, Boston, MA, 02114, USA.
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157
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Jørum E. Advancing methods for characterizing structure and functions of small nerve fibres in neuropathic conditions. Scand J Pain 2016; 10:54-56. [PMID: 28361772 DOI: 10.1016/j.sjpain.2015.09.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ellen Jørum
- Section of Clinical Neurophysiology, Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
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158
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The influence of offset analgesia on the onset and offset of pain in patients with fibromyalgia. Pain 2015; 156:2521-2527. [DOI: 10.1097/j.pain.0000000000000321] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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159
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160
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Abstract
Recent neuroimaging studies suggest that the brain adapts with pain, as well as imparts risk for developing chronic pain. Within this context, we revisit the concepts for nociception, acute and chronic pain, and negative moods relative to behavior selection. We redefine nociception as the mechanism protecting the organism from injury, while acute pain as failure of avoidant behavior, and a mesolimbic threshold process that gates the transformation of nociceptive activity to conscious pain. Adaptations in this threshold process are envisioned to be critical for development of chronic pain. We deconstruct chronic pain into four distinct phases, each with specific mechanisms, and outline current state of knowledge regarding these mechanisms: the limbic brain imparting risk, and the mesolimbic learning processes reorganizing the neocortex into a chronic pain state. Moreover, pain and negative moods are envisioned as a continuum of aversive behavioral learning, which enhance survival by protecting against threats.
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Affiliation(s)
- Marwan N Baliki
- Department of Physiology, Feinberg School of Medicine, 303 East Chicago Avenue, Chicago, IL 60610, USA.
| | - A Vania Apkarian
- Department of Physiology, Feinberg School of Medicine, 303 East Chicago Avenue, Chicago, IL 60610, USA; Department of Anesthesia, Feinberg School of Medicine, 303 East Chicago Avenue, Chicago, IL 60610, USA; Department of Physical Medicine and Rehabilitation, Feinberg School of Medicine, 303 East Chicago Avenue, Chicago, IL 60610, USA.
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161
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Üçeyler N, Zeller J, Kewenig S, Kittel-Schneider S, Fallgatter AJ, Sommer C. Increased cortical activation upon painful stimulation in fibromyalgia syndrome. BMC Neurol 2015; 15:210. [PMID: 26486985 PMCID: PMC4618366 DOI: 10.1186/s12883-015-0472-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 10/13/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fibromyalgia syndrome (FMS) is a chronic condition characterized by widespread pain and associated symptoms. We investigated cerebral activation in FMS patients by functional near-infrared spectroscopy (fNIRS). METHODS Two stimulation paradigms were applied: a) painful pressure stimulation at the dorsal forearm; b) verbal fluency test (VFT). We prospectively recruited 25 FMS patients, ten patients with unipolar major depression (MD) without pain, and 35 healthy controls. All patients underwent neurological examination and all subjects were investigated with questionnaires (pain, depression, FMS, empathy). RESULTS FMS patients had lower pressure pain thresholds than patients with MD and controls (p < .001) and reported higher pain intensity (p < 0.001). Upon unilateral pressure pain stimulation fNIRS recordings revealed increased bilateral cortical activation in FMS patients compared to controls (p < 0.05). FMS patients also displayed a stronger contralateral activity over the dorsolateral prefrontal cortex in direct comparison to patients with MD (p < 0.05). While all three groups performed equally well in the VFT, a frontal deficit in cortical activation was only found in patients with depression (p < 0.05). Performance and cortical activation correlated negatively in FMS patients (p < 0.05) and positively in patients with MD (p < 0.05). CONCLUSION Our data give further evidence for altered central nervous processing in patients with FMS and the distinction between FMS and MD. TRIAL REGISTRATION ISRCTN registry ID ISRCTN15015327 (24.09.2015).
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Affiliation(s)
- Nurcan Üçeyler
- Department of Neurology, University of Würzburg, Josef-Schneider-Str. 11, Würzburg, 97080, Germany.
| | - Julia Zeller
- Department of Psychiatry, University of Würzburg, Würzburg, Germany.
| | - Susanne Kewenig
- Department of Neurology, University of Würzburg, Josef-Schneider-Str. 11, Würzburg, 97080, Germany.
| | | | | | - Claudia Sommer
- Department of Neurology, University of Würzburg, Josef-Schneider-Str. 11, Würzburg, 97080, Germany.
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162
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Ramírez M, Martínez-Martínez LA, Hernández-Quintela E, Velazco-Casapía J, Vargas A, Martínez-Lavín M. Small fiber neuropathy in women with fibromyalgia. An in vivo assessment using corneal confocal bio-microscopy. Semin Arthritis Rheum 2015; 45:214-9. [DOI: 10.1016/j.semarthrit.2015.03.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 03/01/2015] [Accepted: 03/13/2015] [Indexed: 01/25/2023]
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163
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Abstract
BACKGROUND Adjudication of disability claims related to fibromyalgia (FM) syndrome can be a challenging and complex process. A commentary published in the current issue of Pain Research & Management makes suggestions for improvement. The authors of the commentary contend that: previously and currently used criteria for the diagnosis of FM are irrelevant to clinical practice; the opinions of family physicians should supersede those of experts; there is little evidence that trauma can cause FM; no formal instruments are necessary to assess disability; and many FM patients on or applying for disability are exaggerating or malingering, and tests of symptoms validity should be used to identify malingerers. OBJECTIVES To assess the assertions made by Fitzcharles et al. METHODS A narrative review of the available research literature was performed. RESULTS Available diagnostic criteria should be used in a medicolegal context; family physicians are frequently uncertain about FM and⁄or biased; there is considerable evidence that trauma can be a cause of FM; it is essential to use validated instruments to assess functional impairment; and the available tests of physical effort and symptom validity are of uncertain value in identifying malingering in FM. CONCLUSIONS The available evidence does not support many of the suggestions presented in the commentary. Caution is advised in adopting simple solutions for disability adjudication in FM because they are generally incompatible with the inherently complex nature of the problem.
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164
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Abstract
Although fibromyalgia and complex regional pain syndrome (CRPS) have distinct clinical phenotypes, they do share many other features. Pain, allodynia and dysaesthesia occur in each condition and seem to exist on a similar spectrum. Fibromyalgia and CRPS can both be triggered by specific traumatic events, although fibromyalgia is most commonly associated with psychological trauma and CRPS is most often associated with physical trauma, which is frequently deemed routine or minor by the patient. Fibromyalgia and CRPS also seem to share many pathophysiological mechanisms, among which the most important are those involving central effects. Nonetheless, peripheral effects, such as neurogenic neuroinflammation, are also important contributors to the clinical features of each of these disorders. This Review highlights the differing degrees to which neurogenic neuroinflammation might contribute to the multifactorial pathogenesis of both fibromyalgia and CRPS, and discusses the evidence suggesting that this mechanism is an important link between the two disorders, and could offer novel therapeutic targets.
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165
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Olausson P, Gerdle B, Ghafouri N, Sjöström D, Blixt E, Ghafouri B. Protein alterations in women with chronic widespread pain--An explorative proteomic study of the trapezius muscle. Sci Rep 2015; 5:11894. [PMID: 26150212 PMCID: PMC4493691 DOI: 10.1038/srep11894] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 06/09/2015] [Indexed: 12/18/2022] Open
Abstract
Chronic widespread pain (CWP) has a high prevalence in the population and is associated with prominent negative individual and societal consequences. There is no clear consensus concerning the etiology behind CWP although alterations in the central processing of nociception maintained by peripheral nociceptive input has been suggested. Here, we use proteomics to study protein changes in trapezius muscle from 18 female patients diagnosed with CWP compared to 19 healthy female subjects. The 2-dimensional gel electrophoresis (2-DE) in combination with multivariate statistical analyses revealed 17 proteins to be differently expressed between the two groups. Proteins were identified by mass spectrometry. Many of the proteins are important enzymes in metabolic pathways like the glycolysis and gluconeogenesis. Other proteins are associated with muscle damage, muscle recovery, stress and inflammation. The altered expressed levels of these proteins suggest abnormalities and metabolic changes in the myalgic trapezius muscle in CWP. Taken together, this study gives further support that peripheral factors may be of importance in maintaining CWP.
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Affiliation(s)
- Patrik Olausson
- Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University and Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, Region Östergötland
| | - Björn Gerdle
- Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University and Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, Region Östergötland
| | - Nazdar Ghafouri
- Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University and Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, Region Östergötland
| | - Dick Sjöström
- Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University and Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, Region Östergötland
| | - Emelie Blixt
- Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University and Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, Region Östergötland
| | - Bijar Ghafouri
- Division of Community Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University and Pain and Rehabilitation Center, Anaesthetics, Operations and Specialty Surgery Center, Region Östergötland
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166
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Kim J, Loggia ML, Cahalan CM, Harris RE, Beissner F, Garcia RG, Kim H, Wasan AD, Edwards RR, Napadow V. The somatosensory link in fibromyalgia: functional connectivity of the primary somatosensory cortex is altered by sustained pain and is associated with clinical/autonomic dysfunction. Arthritis Rheumatol 2015; 67:1395-1405. [PMID: 25622796 DOI: 10.1002/art.39043] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Accepted: 01/15/2015] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Fibromyalgia (FM) is a chronic functional pain syndrome characterized by widespread pain, significant pain catastrophizing, sympathovagal dysfunction, and amplified temporal summation for evoked pain. While several studies have demonstrated altered resting brain connectivity in FM, studies have not specifically probed the somatosensory system and its role in both somatic and nonsomatic FM symptoms. Our objective was to evaluate resting primary somatosensory cortex (S1) connectivity and to explore how sustained, evoked deep tissue pain modulates this connectivity. METHODS We acquired functional magnetic resonance imaging and electrocardiography data on FM patients and healthy controls during rest (the rest phase) and during sustained mechanical pressure-induced pain over the lower leg (the pain phase). Functional connectivity associated with different S1 subregions was calculated, while S1(leg) connectivity (representation of the leg in the primary somatosensory cortex) was contrasted between the rest phase and the pain phase and was correlated with clinically relevant measures in FM. RESULTS During the rest phase, FM patients showed decreased connectivity between multiple ipsilateral and cross-hemispheric S1 subregions, which was correlated with clinical pain severity. Compared to the rest phase, the pain phase produced increased S1(leg) connectivity to the bilateral anterior insula in FM patients, but not in healthy controls. Moreover, in FM patients, sustained pain-altered S1(leg) connectivity to the anterior insula was correlated with clinical/behavioral pain measures and autonomic responses. CONCLUSION Our study demonstrates that both somatic and nonsomatic dysfunction in FM, including clinical pain, pain catastrophizing, autonomic dysfunction, and amplified temporal summation, are closely linked with the degree to which evoked deep tissue pain alters S1 connectivity to salience/affective pain-processing regions. Additionally, diminished connectivity between S1 subregions during the rest phase in FM may result from ongoing widespread clinical pain.
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Affiliation(s)
- Jieun Kim
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA.,Division of Medical Research, Korea Institute of Oriental Medicine, Daejeon, Korea
| | - Marco L Loggia
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA.,Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School (HMS), Chestnut Hill, MA, USA
| | - Christine M Cahalan
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School (HMS), Chestnut Hill, MA, USA
| | - Richard E Harris
- Department of Anesthesiology, Chronic Pain and Fatigue Research Center, University of Michigan Health Center, Ann Arbor, MI, USA
| | - Florian Beissner
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA.,Somatosensory and Autonomic Therapy Research, Institute for Neuroradiology, Hannover Medical School, Hannover, Germany
| | - Ronald G Garcia
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA.,Masira Research Institute, School of Medicine, Universidad de Santander, Bucaramanga, Colombia
| | - Hyungjun Kim
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA.,Division of Medical Research, Korea Institute of Oriental Medicine, Daejeon, Korea
| | - Ajay D Wasan
- Departments of Anesthesiology and Psychiatry, University of Pittsburgh School of Medicine, PA, USA
| | - Robert R Edwards
- Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School (HMS), Chestnut Hill, MA, USA.,Department of Psychiatry, Brigham and Women's Hospital, HMS, Boston, MA, USA
| | - Vitaly Napadow
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA.,Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, Harvard Medical School (HMS), Chestnut Hill, MA, USA.,Department of Biomedical Engineering, College of Electronics and Information, Kyung Hee University, Yongin, Korea
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167
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Lukkahatai N, Walitt B, Espina A, Wang D, Saligan LN. Comparing Genomic Profiles of Women With and Without Fibromyalgia. Biol Res Nurs 2015; 17:373-83. [PMID: 26015072 DOI: 10.1177/1099800415589785] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND Fibromyalgia syndrome (FMS), a chronic musculoskeletal condition characterized by diffuse pain, fatigue, sleep impairment, and cognitive dysfunction, is associated with significant functional disability. Its underlying biological mechanisms are unknown. This study investigated differentially expressed genes between women with FMS and healthy volunteers. METHODS Women who met the 1990 or 2010 American College of Rheumatology fibromyalgia criteria were compared to age- and race-matched pain-free healthy women. Peripheral blood samples were collected, and a full genome microarray gene expression analysis was performed. One-way analysis of variance was used to identify differentially expressed genes using the filtering criterion of 1% false discovery rate. Analysis of canonical pathways associated with these genes was performed. Confirmatory quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay verified microarray results. Independent t-tests compared gene and protein expression between groups. RESULT Participants were 54 women with FMS and 25 controls. Expression arrays from a subset of women with FMS (n = 29) and controls (n = 20) showed upregulation of 12 genes (>1.8-fold change, p < .05) in the FMS sample. Differentially expressed genes were related to B-cell development, primary immunodeficiency signaling, and mitotic roles of polo-like kinase. CENPK and HSP90AA1 were the most differentially expressed genes (p < .01). CONCLUSION Activity of interrelated pathways related to immune response, and homeostasis appears to be relevant to the experience of FMS. Replication and exploration of the relationship between gene expression and symptom severity will help determine clinical relevance of these findings.
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Affiliation(s)
- Nada Lukkahatai
- School of Nursing, University of Nevada, Las Vegas, NV, USA National Institute of Nursing Research (NINR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Brian Walitt
- National Institute of Nursing Research (NINR), National Institutes of Health (NIH), Bethesda, MD, USA Section of Rheumatology, Washington Hospital Center, Washington, DC, USA
| | - Alexandra Espina
- National Institute of Nursing Research (NINR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Dan Wang
- National Institute of Nursing Research (NINR), National Institutes of Health (NIH), Bethesda, MD, USA
| | - Leorey N Saligan
- National Institute of Nursing Research (NINR), National Institutes of Health (NIH), Bethesda, MD, USA
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168
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Staud R, Lucas YE, Price DD, Robinson ME. Effects of milnacipran on clinical pain and hyperalgesia of patients with fibromyalgia: results of a 6-week randomized controlled trial. THE JOURNAL OF PAIN 2015; 16:750-9. [PMID: 25998206 DOI: 10.1016/j.jpain.2015.04.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 04/19/2015] [Accepted: 04/30/2015] [Indexed: 02/06/2023]
Abstract
UNLABELLED Milnacipran is a serotonin-norepinephrine reuptake inhibitor that was approved by the U.S. Food and Drug Administration as effective therapy for fibromyalgia (FM) symptoms. However, its analgesic mechanism of action is not well understood. We hypothesized that improvement of mechanical and heat hyperalgesia would be a critical component of overall milnacipran efficacy in FM. We used a novel quantitative sensory testing protocol for assessment of mechanical and heat pain sensitivity that can be used for testing of peripheral and central pain mechanisms and their impact on clinical pain over time. We applied tonic mechanical and heat pain stimuli to 46 patients with FM during a randomized controlled trial with either 50 mg milnacipran (n = 23) or placebo (n = 23) twice daily over 6 weeks. During this trial, mean clinical pain (standard deviation) was evaluated daily, and mechanical and heat pain sensitivity every 2 weeks. At study entry, clinical pain was 5.0 (1.8) and 5.5 (1.8) visual analog scale units for patients with FM randomized to placebo and milnacipran, respectively (P > .05). Over 6 weeks, clinical pain of patients with FM significantly declined by 15%, but this improvement was not statistically different between milnacipran and placebo. However, repeated measures of mechanical and heat pain sensitivity reliably predicted up to 80% of the variance in clinical FM pain at every time point. Clinical pain and mechanical/heat pain sensitivity of patients with FM steadily declined during this trial, but the effects of milnacipran were not found to be superior to placebo. Repeated measures of mechanical/heat hyperalgesia reliably predicted large amounts of the variance in clinical pain across all participants, indicating their relevance for FM pain. PERSPECTIVE Although clinical pain and hyperalgesia decreased during this 6-week trial, the efficacy of milnacipran was not superior to placebo. The high correlations between clinical pain and hyperalgesia ratings at every time point seem to emphasize the relevant contributions of mechanical and heat hyperalgesia to clinical FM pain.
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Affiliation(s)
- Roland Staud
- Department of Medicine, University of Florida, Gainesville, Florida.
| | - Yesenia E Lucas
- Department of Medicine, University of Florida, Gainesville, Florida
| | - Donald D Price
- Department of Orofacial Surgery, University of Florida, Gainesville, Florida
| | - Michael E Robinson
- Department of Clinical and Health Psychology, University of Florida, Gainesville, Florida
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169
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Clauw DJ. Diagnosing and treating chronic musculoskeletal pain based on the underlying mechanism(s). Best Pract Res Clin Rheumatol 2015; 29:6-19. [PMID: 26266995 DOI: 10.1016/j.berh.2015.04.024] [Citation(s) in RCA: 96] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Until recently, most clinicians considered chronic pain to be typically due to ongoing peripheral nociceptive input (i.e., damage or inflammation) in the region of the body where the individual is experiencing pain. Clinicians are generally aware of a few types of pain (e.g., headache and phantom limb pain) where chronic pain is not due to such causes, but most do not realize there is not a single chronic pain state where any radiographic, surgical, or pathological description of peripheral nociceptive damage has been reproducibly shown to be related to the presence or severity of pain. The primary reason for this appears to be that both the peripheral and central nervous systems play a critical role in determining which nociceptive input being detected by sensory nerves in the peripheral tissues will lead to the perception of pain in humans. This manuscript reviews some of the latest findings regarding the neural processing of pain, with a special focus on how clinicians can use information gleaned from the history and physical examination to assess which mechanisms are most likely to be responsible for pain in a given individual, and tailors therapy appropriately. A critical construct is that, within any specific diagnostic category (e.g., fibromyalgia (FM), osteoarthritis (OA), and chronic low back pain (CLBP) are specifically reviewed), individual patients may have markedly different peripheral/nociceptive and neural contributions to their pain. Thus, just as low back pain has long been acknowledged to have multiple potential mechanisms, so also is this true of all chronic pain states, wherein some individuals will have pain primarily due to peripheral nociceptive input, whereas in others peripheral (e.g., peripheral sensitization) or central nervous system factors ("central sensitization" or "centralization" of pain via augmented pain processing in spinal and brain) may be playing an equally or even more prominent role in their pain and other symptoms.
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Affiliation(s)
- Daniel J Clauw
- Chronic Pain and Fatigue Research Center, The University of Michigan, 24 Frank Lloyd Wright Dr PO Box 385, Ann Arbor, MI 48106, USA.
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170
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Rahm B, Lacour M, Decety J, Müller J, Scheidt CE, Bauer J, König R, Wirsching M, Glauche V, Ohlendorf S, Unterbrink T, Hartmann A, Joos AA. Self-perspective leads to increased activation of pain processing brain regions in fibromyalgia. Compr Psychiatry 2015; 59:80-90. [PMID: 25795103 DOI: 10.1016/j.comppsych.2015.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 01/16/2015] [Accepted: 02/03/2015] [Indexed: 12/19/2022] Open
Abstract
BACKGROUND Dysfunction of central nervous pain processing is assumed to play a key role in primary fibromyalgia (FM) syndrome. This pilot study examined differences of pain processing associated with adopting different interpersonal perspectives. METHODS Eleven FM patients and 11 healthy controls (HC) were scanned with functional magnetic resonance imaging. Participants were trained to take either a self-perspective or another person's perspective when viewing the visual stimuli. Stimuli showed body parts in painful situations of varying intensity (low, medium, and high) and visually similar but neutral situations. RESULTS Patients with FM showed a higher increase in blood oxygen level dependent (BOLD) response, particularly in the supplementary motor area (SMA). All pain-related regions of interest (anterior insula, somatosensory cortices, anterior cingulate cortex, and SMA) showed stronger modulation of BOLD responses in FM patients in the self-perspective. In contrast to pain processing regions, perspective-related regions (e.g. temporoparietal junction) did not differ between FM and HC. CONCLUSIONS The stronger response of all four pain processing cerebral regions during self-perspective is discussed in the light of disturbed bottom-up processing. Furthermore, the results confirm earlier reports of augmented pain processing in FM, and provide evidence for sensitization of central nervous pain processing.
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Affiliation(s)
- Benjamin Rahm
- Medical Psychology and Medical Sociology, Clinic and Polyclinic for Psychosomatic Medicine and Psychotherapy, University Medical Center, Mainz, Germany
| | - Michael Lacour
- Department of Psychosomatic Medicine and Psychotherapy, University of Freiburg, Freiburg, Germany
| | - Jean Decety
- Department of Psychology, and Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, United States
| | - Juliane Müller
- Department of Psychosomatic Medicine and Psychotherapy, University of Freiburg, Freiburg, Germany
| | - Carl-Eduard Scheidt
- Department of Psychosomatic Medicine and Psychotherapy, University of Freiburg, Freiburg, Germany
| | - Joachim Bauer
- Department of Psychosomatic Medicine and Psychotherapy, University of Freiburg, Freiburg, Germany
| | - Ralf König
- Department of Psychosomatic Medicine and Psychotherapy, University of Freiburg, Freiburg, Germany
| | - Michael Wirsching
- Department of Psychosomatic Medicine and Psychotherapy, University of Freiburg, Freiburg, Germany
| | - Volkmar Glauche
- Department of Neurology, University of Freiburg, Freiburg, Germany
| | - Sabine Ohlendorf
- Medical Physics, Department of Radiology, University of Freiburg, Freiburg, Germany
| | - Thomas Unterbrink
- Department of Psychosomatic Medicine and Psychotherapy, University of Freiburg, Freiburg, Germany
| | - Armin Hartmann
- Department of Psychosomatic Medicine and Psychotherapy, University of Freiburg, Freiburg, Germany
| | - Andreas A Joos
- Department of Psychosomatic Medicine and Psychotherapy, University of Freiburg, Freiburg, Germany.
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171
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Bogen O, Bender O, Löwe J, Blenau W, Thevis B, Schröder W, Margolis RU, Levine JD, Hucho F. Neuronally produced versican V2 renders C-fiber nociceptors IB4 -positive. J Neurochem 2015; 134:147-55. [PMID: 25845936 DOI: 10.1111/jnc.13113] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 03/24/2015] [Accepted: 03/25/2015] [Indexed: 12/23/2022]
Abstract
A subpopulation of nociceptors, the glial cell line-derived neurotrophic factor (GDNF)-dependent, non-peptidergic C-fibers, expresses a cell-surface glycoconjugate that can be selectively labeled with isolectin B4 (IB4 ), a homotetrameric plant lectin from Griffonia simplicifolia. We show that versican is an IB4 -binding molecule in rat dorsal root ganglion neurons. Using reverse transcriptase polymerase chain reaction (RT-PCR), in situ hybridization and immunofluorescence experiments on rat lumbar dorsal root ganglion, we provide the first demonstration that versican is produced by neurons. In addition, by probing Western blots with splice variant-specific antibodies we show that the IB4 -binding versican contains only the glycosaminoglycan alpha domain. Our data support V2 as the versican isoform that renders this subpopulation of nociceptors IB4 -positive (+). A subset of nociceptors, the GDNF-dependent non-peptidergic C-fibers can be characterized by its reactivity for isolectin B4 (IB4), a plant lectin from Griffonia simplicifolia. We have previously demonstrated that versican V2 binds IB4 in a Ca2 + -dependent manner. However, given that versican is thought to be the product of glial cells, it was questionable whether versican V2 can be accountable for the IB4-reactivity of this subset of nociceptors. The results presented here prove - for the first time - a neuronal origin of versican and suggest that versican V2 is the molecule that renders GDNF-dependent non-peptidergic C-fibers IB4-positive.
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Affiliation(s)
- Oliver Bogen
- Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany.,Department of Medicine and Oral & Maxillofacial Surgery, University of California San Francisco, San Francisco, California, USA
| | - Olaf Bender
- Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany
| | - Jana Löwe
- Universität Potsdam, Institut für Biochemie und Biologie, Potsdam, Germany
| | - Wolfgang Blenau
- Universität Potsdam, Institut für Biochemie und Biologie, Potsdam, Germany
| | - Beatrice Thevis
- Department of Pain Pharmacology, Grünenthal Innovation, Grünenthal GmbH, Aachen, Germany
| | - Wolfgang Schröder
- Early Clinical Development, Department of Translational Science, Grünenthal Innovation, Grünenthal GmbH, Aachen, Germany
| | - Richard U Margolis
- Department of Biochemistry and Molecular Pharmacology, New York University Medical Center, New York City, New York, USA
| | - Jon D Levine
- Department of Medicine and Oral & Maxillofacial Surgery, University of California San Francisco, San Francisco, California, USA
| | - Ferdinand Hucho
- Institut für Chemie und Biochemie, Freie Universität Berlin, Berlin, Germany
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172
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173
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Affiliation(s)
- Nurcan Üçeyler
- Department of Neurology, University of Würzburg, 97080 Würzburg, Germany
| | - Claudia Sommer
- Department of Neurology, University of Würzburg, 97080 Würzburg, Germany.
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174
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Microneurographic recording from unmyelinated nerve fibers in neurological disorders: An update. Clin Neurophysiol 2015; 126:437-45. [DOI: 10.1016/j.clinph.2014.10.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 09/25/2014] [Accepted: 10/06/2014] [Indexed: 12/14/2022]
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175
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Murai N, Fushiki H, Honda S, Murakami Y, Iwashita A, Irie M, Tamura S, Nagakura Y, Aoki T. Relationship between serotonin transporter occupancies and analgesic effects of AS1069562, the (+)-isomer of indeloxazine, and duloxetine in reserpine-induced myalgia rats. Neuroscience 2015; 289:262-9. [DOI: 10.1016/j.neuroscience.2014.12.065] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 12/22/2014] [Accepted: 12/23/2014] [Indexed: 11/26/2022]
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176
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Merkies ISJ, Faber CG, Lauria G. Advances in diagnostics and outcome measures in peripheral neuropathies. Neurosci Lett 2015; 596:3-13. [PMID: 25703220 DOI: 10.1016/j.neulet.2015.02.038] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 02/05/2015] [Accepted: 02/17/2015] [Indexed: 12/13/2022]
Abstract
Peripheral neuropathies are a group of acquired and hereditary disorders presenting with different distribution and nerve fiber class involvement. The overall prevalence is 2.4%, increasing to 8% in the elderly population. However, the frequency may vary depending on the underlying pathogenesis and association with systemic diseases. Distal symmetric polyneuropathy is the most common form, though multiple mononeuropathies, non-length dependent neuropathy and small fiber neuropathy can occur and may require specific diagnostic tools. The use of uniform outcome measures in peripheral neuropathies is important to improve the quality of randomized controlled trials, enabling comparison between studies. Recent developments in defining the optimal set of outcome measures in inflammatory neuropathies may serve as an example for other conditions. Diagnostic and outcome measure advances in peripheral neuropathies will be discussed.
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Affiliation(s)
- Ingemar S J Merkies
- Department of Neurology, Spaarne Hospital, Hoofddorp, The Netherlands; Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Catharina G Faber
- Department of Neurology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Giuseppe Lauria
- 3rd Neurology Unit, IRCCS Foundation "Carlo Besta" Neurological Institute, Milan, Italy.
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177
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Yilmaz U, Bird TT, Carter GT, Wang LH, Weiss MD. Pain in hereditary neuropathy with liability to pressure palsy: An association with fibromyalgia syndrome? Muscle Nerve 2015; 51:385-90. [DOI: 10.1002/mus.24331] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2014] [Indexed: 12/16/2022]
Affiliation(s)
- Ugur Yilmaz
- Department of Neurology; University of Washington Medical Center; Box 356115, 1959 NE Pacific Street Seattle Washington 98195 USA
| | - Thomas T. Bird
- Department of Neurology; University of Washington Medical Center; Box 356115, 1959 NE Pacific Street Seattle Washington 98195 USA
| | - Gregory T. Carter
- MEDEX Division; University of Washington School of Medicine; Seattle Washington USA
| | - Leo H. Wang
- Department of Neurology; University of Washington Medical Center; Box 356115, 1959 NE Pacific Street Seattle Washington 98195 USA
| | - Michael D. Weiss
- Department of Neurology; University of Washington Medical Center; Box 356115, 1959 NE Pacific Street Seattle Washington 98195 USA
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178
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Jason LA, Zinn ML, Zinn MA. Myalgic Encephalomyelitis: Symptoms and Biomarkers. Curr Neuropharmacol 2015; 13:701-34. [PMID: 26411464 PMCID: PMC4761639 DOI: 10.2174/1570159x13666150928105725] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 04/09/2015] [Accepted: 07/14/2015] [Indexed: 01/01/2023] Open
Abstract
Myalgic Encephalomyelitis (ME) continues to cause significant morbidity worldwide with an estimated one million cases in the United States. Hurdles to establishing consensus to achieve accurate evaluation of patients with ME continue, fueled by poor agreement about case definitions, slow progress in development of standardized diagnostic approaches, and issues surrounding research priorities. Because there are other medical problems, such as early MS and Parkinson's Disease, which have some similar clinical presentations, it is critical to accurately diagnose ME to make a differential diagnosis. In this article, we explore and summarize advances in the physiological and neurological approaches to understanding, diagnosing, and treating ME. We identify key areas and approaches to elucidate the core and secondary symptom clusters in ME so as to provide some practical suggestions in evaluation of ME for clinicians and researchers. This review, therefore, represents a synthesis of key discussions in the literature, and has important implications for a better understanding of ME, its biological markers, and diagnostic criteria. There is a clear need for more longitudinal studies in this area with larger data sets, which correct for multiple testing.
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Affiliation(s)
- Leonard A. Jason
- Department of Psychology, Center for Community Research, DePaul University, Chicago, Illinois, United States
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179
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Karlsson P, Nyengaard JR, Polydefkis M, Jensen TS. Structural and functional assessment of skin nerve fibres in small-fibre pathology. Eur J Pain 2014; 19:1059-70. [PMID: 25546653 DOI: 10.1002/ejp.645] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2014] [Indexed: 01/19/2023]
Abstract
Damage to nociceptor nerve fibres may give rise to peripheral neuropathies, some of which are pain free and some are painful. A hallmark of many peripheral neuropathies is the loss of small nerve fibres in the epidermis, a condition called small-fibre neuropathy (SFN) when it is predominantly the small nerve fibres that are damaged. Historically, SFN has been very difficult to diagnose as clinical examination and nerve conduction studies mainly detect large nerve fibres, and quantitative sensory testing is not sensitive enough to detect small changes in small nerve fibres. However, taking a 3-mm punch skin biopsy from the distal leg and quantification of the nerve fibre density has proven to be a useful method to diagnose SFN. However, the correlation between the nerve fibre loss and other test results varies greatly. Recent studies have shown that it is possible not only to extract information about the nerve fibre density from the biopsies but also to get an estimation of the nerve fibre length density using stereology, quantify sweat gland innervation and detect morphological changes such as axonal swelling, all of which may be additional parameters indicating diseased small fibres relating to symptoms reported by the patients. In this review, we focus on available tests to assess structure and function of the small nerve fibres, and summarize recent advances that have provided new possibilities to more specifically relate structural findings with symptoms and function in patients with SFN.
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Affiliation(s)
- P Karlsson
- Danish Pain Research Center and Stereology & EM Laboratory, Aarhus University Hospital, Denmark.,Stereology and Electron Microscopy Laboratory and Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University Hospital, Denmark
| | - J R Nyengaard
- Stereology and Electron Microscopy Laboratory and Centre for Stochastic Geometry and Advanced Bioimaging, Aarhus University Hospital, Denmark
| | - M Polydefkis
- Department of Neurology, The Johns Hopkins Hospital, Baltimore, MD, USA
| | - T S Jensen
- Danish Pain Research Center and Stereology & EM Laboratory, Aarhus University Hospital, Denmark.,Department of Neurology, Aarhus University Hospital, Denmark
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180
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Neuropathies douloureuses et atteinte des petites fibres. Rev Neurol (Paris) 2014; 170:825-36. [DOI: 10.1016/j.neurol.2014.10.008] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 10/10/2014] [Indexed: 12/16/2022]
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181
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Gemignani F. Fibromyalgia Syndrome and Small-Fiber Neuropathy: Comment on the Article by Caro and Winter. Arthritis Rheumatol 2014; 66:3526-7. [DOI: 10.1002/art.38812] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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182
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Gemignani F. Fibromyalgia syndrome and small-fiber neuropathy. Ann Neurol 2014; 76:916. [DOI: 10.1002/ana.24269] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Revised: 05/15/2014] [Accepted: 09/01/2014] [Indexed: 11/06/2022]
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183
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Affiliation(s)
- J Serra
- Neuroscience Technologies, Ltd.; Barcelona Spain
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184
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Üçeyler N, Kewenig S, Kafke W, Kittel-Schneider S, Sommer C. Skin cytokine expression in patients with fibromyalgia syndrome is not different from controls. BMC Neurol 2014; 14:185. [PMID: 25240423 PMCID: PMC4175620 DOI: 10.1186/s12883-014-0185-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 09/17/2014] [Indexed: 01/25/2023] Open
Abstract
Background Fibromyalgia syndrome (FMS) is a chronic pain syndrome of unknown etiology. There is increasing evidence for small nerve fiber impairment in a subgroup of patients with FMS. We investigated whether skin cytokine and delta opioid receptor (DOR) gene expression in FMS patients differs from controls as one potential contributor to small nerve fiber sensitization. Methods We investigated skin punch biopsies of 25 FMS patients, ten patients with monopolar depression but no pain, and 35 healthy controls. Biopsies were obtained from the lateral upper thigh and lower calf. Gene expression of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF), interleukin (IL)-6, and IL-8 and of the anti-inflammatory cytokine IL-10 was analyzed using quantitative real-time PCR and normalizing data to 18sRNA as housekeeping gene. Additionally, we assessed DOR gene expression. Results All cytokines and DOR were detectable in skin samples of FMS patients, patients with depression, and healthy controls without intergroup difference. Also, gene expression was not different in skin of the upper and lower leg within and between the groups and in FMS patient subgroups. Conclusions Skin cytokine and DOR gene expression does not differ between patients with FMS and controls. Our results do not support a role of the investigated cytokines in sensitization of peripheral nerve fibers as a potential mechanism of small fiber pathology in FMS.
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185
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Serra J, Collado A, Solà R, Antonelli F, Torres X, Salgueiro M, Quiles C, Bostock H. Reply: To PMID 24243538. Ann Neurol 2014; 76:917-8. [PMID: 25186091 DOI: 10.1002/ana.24268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jordi Serra
- Department of Neurology, MC Mutual, Barcelona, Spain; Neuroscience Technologies, Barcelona Science Park, Barcelona, Spain
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186
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Woolf CJ. What to call the amplification of nociceptive signals in the central nervous system that contribute to widespread pain? Pain 2014; 155:1911-1912. [PMID: 25083929 DOI: 10.1016/j.pain.2014.07.021] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2014] [Accepted: 07/24/2014] [Indexed: 11/19/2022]
Affiliation(s)
- Clifford J Woolf
- FM Kirby Neurobiology Center, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
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187
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Mario Campero S. ¿Es posible objetivar el dolor? REVISTA MÉDICA CLÍNICA LAS CONDES 2014. [DOI: 10.1016/s0716-8640(14)70080-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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