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Jin S, Cho HJ. Cerebral hemodynamics as biomarkers for neuropathic pain in rats: a longitudinal study using a spinal nerve ligation model. Pain 2024:00006396-990000000-00655. [PMID: 38985168 DOI: 10.1097/j.pain.0000000000003332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 06/07/2024] [Indexed: 07/11/2024]
Abstract
ABSTRACT Neuropathic pain is one of the most challenging types of pain to diagnose and treat, a problem exacerbated by the lack of a quantitative biomarker. Recently, several clinical and preclinical studies have shown that neuropathic pain induces cerebral hemodynamic changes as a result of neuroplasticity in the brain. Our hypothesis in this study is that neuropathic pain leads to cerebral hemodynamic changes over postoperative time in a spinal nerve ligation (SNL) rat model, which has not been longitudinally explored previously. Furthermore, by identifying multiple regional hemodynamic features that are the most distinct between SNL and sham groups, where the sham group underwent only an incision without SNL, it may be possible to classify the SNL group regardless of when the onset of pain occurs. We investigate cerebral hemodynamic changes using dynamic susceptibility contrast magnetic resonance imaging in a rat model up to 28 days after ligating L5/L6 spinal nerves. We trained a linear support vector machine with relative cerebral blood volume data from different brain regions and found that the prediction model trained on the nucleus accumbens, motor cortex, pretectal area, and thalamus classified the SNL group and sham group at a 79.27% balanced accuracy, regardless of when the onset of pain occurred (SNL/sham: 60/45 data points). From the use of the SNL model without prior knowledge of the onset time of pain, the current findings highlight the potential of relative cerebral blood volume in the 4 highlighted brain regions as a biomarker for neuropathic pain.
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Affiliation(s)
- Seokha Jin
- Department of Biomedical Engineering, Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
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2
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Meylakh N, Crawford LS, Mills EP, Macefield VG, Vickers ER, Macey PM, Keay KA, Henderson LA. Altered Corticobrainstem Connectivity during Spontaneous Fluctuations in Pain Intensity in Painful Trigeminal Neuropathy. eNeuro 2024; 11:ENEURO.0522-23.2024. [PMID: 38997145 PMCID: PMC11277291 DOI: 10.1523/eneuro.0522-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 06/02/2024] [Accepted: 06/06/2024] [Indexed: 07/14/2024] Open
Abstract
Chronic neuropathic pain can result from nervous system injury and can persist in the absence of external stimuli. Although ongoing pain characterizes the disorder, in many individuals, the intensity of this ongoing pain fluctuates dramatically. Previously, it was identified that functional magnetic resonance imaging signal covariations between the midbrain periaqueductal gray (PAG) matter, rostral ventromedial medulla (RVM), and spinal trigeminal nucleus are associated with moment-to-moment fluctuations in pain intensity in individuals with painful trigeminal neuropathy (PTN). Since this brainstem circuit is modulated by higher brain input, we sought to determine which cortical sites might be influencing this brainstem network during spontaneous fluctuations in pain intensity. Over 12 min, we recorded the ongoing pain intensity in 24 PTN participants and classified them as fluctuating (n = 13) or stable (n = 11). Using a PAG seed, we identified connections between the PAG and emotional-affective sites such as the hippocampal and posterior cingulate cortices, the sensory-discriminative posterior insula, and cognitive-affective sites such as the dorsolateral prefrontal (dlPFC) and subgenual anterior cingulate cortices that were altered dependent on spontaneous high and low pain intensity. Additionally, sliding-window functional connectivity analysis revealed that the dlPFC-PAG connection anticorrelated with perceived pain intensity over the entire 12 min period. These findings reveal cortical systems underlying moment-to-moment changes in perceived pain in PTN, which likely cause dysregulation in the brainstem circuits previously identified, and consequently alter the appraisal of pain across time.
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Affiliation(s)
- Noemi Meylakh
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2050, Australia
| | - Lewis S Crawford
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2050, Australia
| | - Emily P Mills
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2050, Australia
| | - Vaughan G Macefield
- Department of Neuroscience, Monash University, Melbourne, Victoria 3800, Australia
| | - E Russell Vickers
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2050, Australia
| | - Paul M Macey
- UCLA School of Nursing and Brain Research Institute, University of California, Los Angeles, California 90095
| | - Kevin A Keay
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2050, Australia
| | - Luke A Henderson
- School of Medical Sciences (Neuroscience), Brain and Mind Centre, University of Sydney, Sydney, New South Wales 2050, Australia
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Fu Z, Zhu H, Zhang Y, Huan R, Chen S, Pan Y. A Spatiotemporal Deep Learning Framework for Scalp EEG-Based Automated Pain Assessment in Children. IEEE Trans Biomed Eng 2024; 71:1889-1900. [PMID: 38231823 DOI: 10.1109/tbme.2024.3355215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
OBJECTIVE Common pain assessment approaches such as self-evaluation and observation scales are inappropriate for children as they require patients to have reasonable communication ability. Subjective, inconsistent, and discontinuous pain assessment in children may reduce therapeutic effectiveness and thus affect their later life. METHODS To address the need for suitable assessment measures, this paper proposes a spatiotemporal deep learning framework for scalp electroencephalogram (EEG)-based automated pain assessment in children. The dataset comprises scalp EEG data recorded from 33 pediatric patients with an arterial puncture as a pain stimulus. Two electrode reduction plans in line with clinical findings are proposed. Combining three-dimensional hand-crafted features and preprocessed raw signals, the proposed transformer-based pain assessment network (STPA-Net) integrates both spatial and temporal information. RESULTS STPA-Net achieves superior performance with a subject-independent accuracy of 87.83% for pain recognition, and outperforms other state-of-the-art approaches. The effectiveness of electrode combinations is explored to analyze pain-related cortical activities and correspondingly reduce cost. The two proposed electrode reduction plans both demonstrate competitive pain assessment performance qualitatively and quantitatively. CONCLUSION AND SIGNIFICANCE This study is the first to develop a scalp EEG-based automated pain assessment for children adopting a method that is objective, standardized, and consistent. The findings provide a potential reference for future clinical research.
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Hu Y, Ma J, Chen B, Pang J, Liang W, Wu W. The Duration of Chronic Pain Can Affect Brain Functional Changes of the Pain Matrix in Patients with Chronic Back Pain: A Resting-State fMRI Study. J Pain Res 2024; 17:1941-1951. [PMID: 38828086 PMCID: PMC11141710 DOI: 10.2147/jpr.s457575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 05/13/2024] [Indexed: 06/05/2024] Open
Abstract
Purpose This study was conducted to explore the differences in functional changes in the pain matrix in patients with chronic back pain (CBP) at different stages and identify whether these brain changes were related to the pain duration. Patients and Methods In this study, 29 healthy individuals and 54 patients with CBP were recruited. According to the pain duration, 25 patients (3 to 12 months) were divided into the CBP-S group and 29 patients (≥ 24 months) were divided into the CBP-L group. All subjects completed clinical pain-related measurement and functional magnetic resonance imaging (fMRI) scans. Moreover, the amplitude of low-frequency fluctuation (ALFF), functional connectivity (FC), and correlation analysis were conducted in this study. Results Compared with healthy controls, patients in the CBP-L group showed significantly decreased ALFF in the left precuneus. In the FC analysis, patients in the CBP-S and CBP-L groups showed significantly decreased FC in several regions in the bilateral orbitofrontal cortices (OFC) and the left ventral posterior insula. Moreover, there were significant differences in the FC between the left hyper granular insula and the probabilistic area in OFC in pairwise group comparisons. The correlation analysis results demonstrated that pain duration was correlated with these functional brain changes, and the ANCOVA results revealed that pain intensity and pain interference scores did not affect the FC analysis results. Conclusion There are different changes in the pain neural matrix in patients with chronic pain at different stages. Furthermore, the pain duration is related to brain functional changes.
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Affiliation(s)
- Yingxuan Hu
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China
| | - Junqin Ma
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China
| | - Bingmei Chen
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China
| | - Jiahui Pang
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China
| | - Wen Liang
- Department of Radiology, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China
| | - Wen Wu
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, People’s Republic of China
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Emvalomenos GM, Kang JWM, Jupp B, Mychasiuk R, Keay KA, Henderson LA. Recent developments and challenges in positron emission tomography imaging of gliosis in chronic neuropathic pain. Pain 2024:00006396-990000000-00597. [PMID: 38713812 DOI: 10.1097/j.pain.0000000000003247] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Accepted: 03/05/2024] [Indexed: 05/09/2024]
Abstract
ABSTRACT Understanding the mechanisms that underpin the transition from acute to chronic pain is critical for the development of more effective and targeted treatments. There is growing interest in the contribution of glial cells to this process, with cross-sectional preclinical studies demonstrating specific changes in these cell types capturing targeted timepoints from the acute phase and the chronic phase. In vivo longitudinal assessment of the development and evolution of these changes in experimental animals and humans has presented a significant challenge. Recent technological advances in preclinical and clinical positron emission tomography, including the development of specific radiotracers for gliosis, offer great promise for the field. These advances now permit tracking of glial changes over time and provide the ability to relate these changes to pain-relevant symptomology, comorbid psychiatric conditions, and treatment outcomes at both a group and an individual level. In this article, we summarize evidence for gliosis in the transition from acute to chronic pain and provide an overview of the specific radiotracers available to measure this process, highlighting their potential, particularly when combined with ex vivo/in vitro techniques, to understand the pathophysiology of chronic neuropathic pain. These complementary investigations can be used to bridge the existing gap in the field concerning the contribution of gliosis to neuropathic pain and identify potential targets for interventions.
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Affiliation(s)
- Gaelle M Emvalomenos
- School of Medical Sciences [Neuroscience], and the Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - James W M Kang
- School of Medical Sciences [Neuroscience], and the Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Bianca Jupp
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Australia
| | - Kevin A Keay
- School of Medical Sciences [Neuroscience], and the Brain and Mind Centre, The University of Sydney, Sydney, Australia
| | - Luke A Henderson
- School of Medical Sciences [Neuroscience], and the Brain and Mind Centre, The University of Sydney, Sydney, Australia
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Szabo E, Ashina S, Melo-Carrillo A, Bolo NR, Borsook D, Burstein R. Peripherally acting anti-CGRP monoclonal antibodies alter cortical gray matter thickness in migraine patients: A prospective cohort study. Neuroimage Clin 2023; 40:103531. [PMID: 37866119 PMCID: PMC10623369 DOI: 10.1016/j.nicl.2023.103531] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 10/13/2023] [Accepted: 10/13/2023] [Indexed: 10/24/2023]
Abstract
Migraine is underpinned by central nervous system neuroplastic alterations thought to be caused by the repetitive peripheral afferent barrage the brain receives during the headache phase (cortical hyperexcitability). Calcitonin gene-related peptide monoclonal antibodies (anti-CGRP-mAbs) are highly effective migraine preventative treatments. Their ability to alter brain morphometry in treatment-responders vs. non-responders is not well understood. Our aim was to determine the effects of the anti-CGRP-mAb galcanezumab on cortical thickness after 3-month treatment of patients with high-frequency episodic or chronic migraine. High-resolution magnetic resonance imaging was performed pre- and post-treatment in 36 migraine patients. In this group, 19 patients were classified responders (≥50 % reduction in monthly migraine days) and 17 were considered non-responders (<50 % reduction in monthly migraine days). Following cross-sectional processing to analyze the baseline differences in cortical thickness, two-stage longitudinal processing and symmetrized percent change were conducted to investigate treatment-related brain changes. At baseline, no significant differences were found between the responders and non-responders. After 3-month treatment, decreased cortical thickness (compared to baseline) was observed in the responders in regions of the somatosensory cortex, anterior cingulate cortex, medial frontal cortex, superior frontal gyrus, and supramarginal gyrus. Non-responders demonstrated decreased cortical thickness in the left dorsomedial cortex and superior frontal gyrus. We interpret the cortical thinning seen in the responder group as suggesting that reduction in head pain could lead to changes in neural swelling and dendritic complexity and that such changes reflect the recovery process from maladaptive neural activity. This conclusion is further supported by our recent study showing that 3 months after treatment initiation, the incidence of premonitory symptoms and prodromes that are followed by headache decreases but not the incidence of the premonitory symptoms or prodromes themselves (that is, cortical thinning relates to reductions in the nociceptive signals in the responders). We speculate that a much longer recovery period is required to allow the brain to return to a more 'normal' functioning state whereby prodromes and premonitory symptoms no longer occur.
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Affiliation(s)
- Edina Szabo
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA; Department of Anaesthesiology, Harvard Medical School, Boston, MA 02215, USA
| | - Sait Ashina
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA; Department of Anaesthesiology, Harvard Medical School, Boston, MA 02215, USA; Comprehensive Headache Center, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA; Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
| | - Agustin Melo-Carrillo
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA; Department of Anaesthesiology, Harvard Medical School, Boston, MA 02215, USA
| | - Nicolas R Bolo
- Department of Psychiatry, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA 02215, USA
| | - David Borsook
- Department of Anaesthesiology, Harvard Medical School, Boston, MA 02215, USA; Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02215, USA; Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02215, USA
| | - Rami Burstein
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA; Department of Anaesthesiology, Harvard Medical School, Boston, MA 02215, USA; Comprehensive Headache Center, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
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Hervert EA, Birdsong W. The Endogenous Opioid Met-Enkephalin Modulates Thalamo-Cortical Excitation Inhibition Balance in a Medial Thalamus-Anterior Cingulate Cortex Circuit. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.13.547220. [PMID: 37503144 PMCID: PMC10369945 DOI: 10.1101/2023.07.13.547220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Activation of opioid receptors in the anterior cingulate cortex (ACC) mediates aspects of analgesia induced by both exogenous and endogenous opioids. We have previously shown that opioid signaling disrupts both afferent excitatory and indirect inhibitory synaptic transmission from the medial thalamus (MThal) to the ACC, but the effects of endogenous opioids within this circuit remain poorly understood. The goal of the current study was to understand how the endogenous opioid, [Met]5-enkephalin (ME), modulates thalamic-driven excitatory and inhibitory synaptic transmission onto layer V pyramidal neurons in the ACC. We used pharmacology, brain slice electrophysiology and optogenetic stimulation to study opioid-mediated modulation of optically evoked glutamatergic and GABAergic transmission. The results revealed that ME inhibited both AMPA-mediated excitatory and GABA-mediated inhibitory synaptic transmission in the ACC. However, inhibitory transmission was more potently inhibited than excitatory transmission by ME. This preferential reduction in GABAA-mediated synaptic transmission was primarily due to the activation of delta opioid receptors by ME and resulted in a net disinhibition of MThal-ACC excitatory pathway. These results suggest that moderate concentrations of ME can lead to net excitation of ACC circuitry and that analgesia may be associated with disinhibition rather than inhibition of ACC subcircuits.
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Affiliation(s)
| | - William Birdsong
- Department of Pharmacology, University of Michigan, Ann Arbor, MI
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Labrakakis C. The Role of the Insular Cortex in Pain. Int J Mol Sci 2023; 24:ijms24065736. [PMID: 36982807 PMCID: PMC10056254 DOI: 10.3390/ijms24065736] [Citation(s) in RCA: 35] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Revised: 03/09/2023] [Accepted: 03/15/2023] [Indexed: 03/19/2023] Open
Abstract
The transition from normal to chronic pain is believed to involve alterations in several brain areas that participate in the perception of pain. These plastic changes are then responsible for aberrant pain perception and comorbidities. The insular cortex is consistently found activated in pain studies of normal and chronic pain patients. Functional changes in the insula contribute to chronic pain; however, the complex mechanisms by which the insula is involved in pain perception under normal and pathological conditions are still not clear. In this review, an overview of the insular function is provided and findings on its role in pain from human studies are summarized. Recent progress on the role of the insula in pain from preclinical experimental models is reviewed, and the connectivity of the insula with other brain regions is examined to shed new light on the neuronal mechanisms of the insular cortex’s contribution to normal and pathological pain sensation. This review underlines the need for further studies on the mechanisms underlying the involvement of the insula in the chronicity of pain and the expression of comorbid disorders.
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Affiliation(s)
- Charalampos Labrakakis
- Department of Biological Applications and Technology, University of Ioannina, 45110 Ioannina, Greece;
- Institute of Biosciences, University Research Center of Ioannina (URCI), 45110 Ioannina, Greece
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Meregalli C, Monza L, Jongen JLM. A mechanistic understanding of the relationship between skin innervation and chemotherapy-induced neuropathic pain. FRONTIERS IN PAIN RESEARCH (LAUSANNE, SWITZERLAND) 2022; 3:1066069. [PMID: 36582196 PMCID: PMC9792502 DOI: 10.3389/fpain.2022.1066069] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 11/24/2022] [Indexed: 12/14/2022]
Abstract
Neuropathic pain is a frequent complication of chemotherapy-induced peripheral neurotoxicity (CIPN). Chemotherapy-induced peripheral neuropathies may serve as a model to study mechanisms of neuropathic pain, since several other common causes of peripheral neuropathy like painful diabetic neuropathy may be due to both neuropathic and non-neuropathic pain mechanisms like ischemia and inflammation. Experimental studies are ideally suited to study changes in morphology, phenotype and electrophysiologic characteristics of primary afferent neurons that are affected by chemotherapy and to correlate these changes to behaviors reflective of evoked pain, mainly hyperalgesia and allodynia. However, hyperalgesia and allodynia may only represent one aspect of human pain, i.e., the sensory-discriminative component, while patients with CIPN often describe their pain using words like annoying, tiring and dreadful, which are affective-emotional descriptors that cannot be tested in experimental animals. To understand why some patients with CIPN develop neuropathic pain and others not, and which are the components of neuropathic pain that they are experiencing, experimental and clinical pain research should be combined. Emerging evidence suggests that changes in subsets of primary afferent nerve fibers may contribute to specific aspects of neuropathic pain in both preclinical models and in patients with CIPN. In addition, the role of cutaneous neuroimmune interactions is considered. Since obtaining dorsal root ganglia and peripheral nerves in patients is problematic, analyses performed on skin biopsies from preclinical models as well as patients provide an opportunity to study changes in primary afferent nerve fibers and to associate these changes to human pain. In addition, other biomarkers of small fiber damage in CIPN, like corneal confocal microscope and quantitative sensory testing, may be considered.
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Affiliation(s)
- Cristina Meregalli
- School of Medicine and Surgery, Experimental Neurology Unit and Milan Center for Neuroscience, University of Milano-Bicocca, Monza, Italy,Correspondence: Cristina Meregalli
| | - Laura Monza
- School of Medicine and Surgery, Experimental Neurology Unit and Milan Center for Neuroscience, University of Milano-Bicocca, Monza, Italy
| | - Joost L. M. Jongen
- Department of Neurology, Brain Tumor Center, Erasmus MC Cancer Institute, Rotterdam, Netherlands
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Lia EN, Papassidero PC, Coelho EB, Dach F, Alexandre-Santos L, Trevisan AC, Santos LELE, Silvah JH, Lanchote VL, Pasqua OD, Wichert-Ana L. Neurobiological substrates of chronic low back pain (CLBP): a brain [ 99mTc]Tc-ECD SPECT study. Eur J Hybrid Imaging 2022; 6:26. [PMID: 36404393 PMCID: PMC9676153 DOI: 10.1186/s41824-022-00145-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 07/18/2022] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Recent neuroimaging studies have demonstrated pathological mechanisms related to cerebral neuroplasticity in chronic low back pain (CLBP). Few studies have compared cerebral changes between patients with and without pain in the absence of an experimentally induced stimulus. We investigated the neurobiological substrates associated with chronic low back pain using [99mTc]Tc-ECD brain SPECT and correlated rCBF findings with the numeric rating scale (NRS) of pain and douleur neuropathique en 4 questions (DN4). Ten healthy control volunteers and fourteen patients with neuropathic CLBP due to lumbar disc herniation underwent cerebral SPECT scans. A quantitative comparison of rCBF findings between patients and controls was made using the Statistical Parametric Mapping (SPM), revealing clusters of voxels with a significant increase or decrease in rCBF. The intensity of CLBP was assessed by NRS and by DN4. RESULTS The results demonstrated an rCBF increase in clusters A (occipital and posterior cingulate cortex) and B (right frontal) and a decrease in cluster C (superior parietal lobe and middle cingulate cortex). NRS scores were inversely and moderately correlated with the intensity of rCBF increase in cluster B, but not to rCBF changes in clusters A and C. DN4 scores did not correlate with rCBF changes in all three clusters. CONCLUSIONS This study will be important for future therapeutic studies that aim to validate the association of rCBF findings with the pharmacokinetic and pharmacodynamic profiles of therapeutic challenges in pain.
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Affiliation(s)
- Erica Negrini Lia
- grid.7632.00000 0001 2238 5157Department of Dentistry, School of Health Sciences, University of Brasilia (UnB), Brasilia, DF Brazil
| | - Priscila Colavite Papassidero
- grid.11899.380000 0004 1937 0722Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP Brazil
| | - Eduardo Barbosa Coelho
- grid.11899.380000 0004 1937 0722Department of Internal Medicine, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP Brazil
| | - Fabíola Dach
- grid.11899.380000 0004 1937 0722Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP Brazil
| | - Leonardo Alexandre-Santos
- grid.11899.380000 0004 1937 0722Nuclear Medicine and PET/CT Laboratory, Department of Medical Imaging, Hematology and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP Brazil
| | - Ana Carolina Trevisan
- grid.11899.380000 0004 1937 0722Nuclear Medicine and PET/CT Laboratory, Department of Medical Imaging, Hematology and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP Brazil
| | - Lucas Emmanuel Lopes e Santos
- grid.11899.380000 0004 1937 0722Nuclear Medicine and PET/CT Laboratory, Department of Medical Imaging, Hematology and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP Brazil
| | - Jose Henrique Silvah
- grid.11899.380000 0004 1937 0722Nuclear Medicine and PET/CT Laboratory, Department of Medical Imaging, Hematology and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP Brazil
| | - Vera Lúcia Lanchote
- grid.11899.380000 0004 1937 0722Department of Clinical Analysis, Food Science and Toxicology, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP Brazil
| | - Oscar Della Pasqua
- grid.83440.3b0000000121901201Clinical Pharmacology and Therapeutics, School of Life and Medical Sciences, University College London, London, UK
| | - Lauro Wichert-Ana
- grid.11899.380000 0004 1937 0722Department of Internal Medicine, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP Brazil ,grid.11899.380000 0004 1937 0722Nuclear Medicine and PET/CT Laboratory, Department of Medical Imaging, Hematology and Clinical Oncology, Ribeirão Preto Medical School, University of São Paulo (USP), Ribeirão Preto, SP Brazil ,Seção de Medicina Nuclear, Hospital das Clínicas – FMRP – USP, Av. Bandeirantes, 3900, CEP: 14048-900 Ribeirão Preto, SP Brasil
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Pricope CV, Tamba BI, Stanciu GD, Cuciureanu M, Neagu AN, Creanga-Murariu I, Dobrovat BI, Uritu CM, Filipiuc SI, Pricope BM, Alexa-Stratulat T. The Roles of Imaging Biomarkers in the Management of Chronic Neuropathic Pain. Int J Mol Sci 2022; 23:13038. [PMID: 36361821 PMCID: PMC9657736 DOI: 10.3390/ijms232113038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/22/2022] [Accepted: 10/24/2022] [Indexed: 08/04/2023] Open
Abstract
Chronic neuropathic pain (CNP) affects around 10% of the general population and has a significant social, emotional, and economic impact. Current diagnosis techniques rely mainly on patient-reported outcomes and symptoms, which leads to significant diagnostic heterogeneity and subsequent challenges in management and assessment of outcomes. As such, it is necessary to review the approach to a pathology that occurs so frequently, with such burdensome and complex implications. Recent research has shown that imaging methods can detect subtle neuroplastic changes in the central and peripheral nervous system, which can be correlated with neuropathic symptoms and may serve as potential markers. The aim of this paper is to review available imaging methods used for diagnosing and assessing therapeutic efficacy in CNP for both the preclinical and clinical setting. Of course, further research is required to standardize and improve detection accuracy, but available data indicate that imaging is a valuable tool that can impact the management of CNP.
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Affiliation(s)
- Cosmin Vasilica Pricope
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
- Department of Pharmacology, Clinical Pharmacology and Algesiology, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Bogdan Ionel Tamba
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
- Department of Pharmacology, Clinical Pharmacology and Algesiology, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Gabriela Dumitrita Stanciu
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Magdalena Cuciureanu
- Department of Pharmacology, Clinical Pharmacology and Algesiology, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Anca Narcisa Neagu
- Laboratory of Animal Histology, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, Carol I bvd. No. 22, 700505 Iasi, Romania
| | - Ioana Creanga-Murariu
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Bogdan-Ionut Dobrovat
- Department of Radiology, Grigore T. Popa University of Medicine and Pharmacy of Iasi, 16 University Street, 700115 Iasi, Romania
| | - Cristina Mariana Uritu
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Silviu Iulian Filipiuc
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Bianca-Mariana Pricope
- Department of Preventive Medicine and Interdisciplinarity, Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
| | - Teodora Alexa-Stratulat
- Advanced Research and Development Center for Experimental Medicine (CEMEX), Grigore T. Popa University of Medicine and Pharmacy, 16 Universitatii Street, 700115 Iasi, Romania
- Medical Oncology-Radiotherapy Department, Grigore T. Popa University of Medicine and Pharmacy, 16 University Street, 700115 Iasi, Romania
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Abstract
Pain is an unpleasant sensory and emotional experience. Understanding the neural mechanisms of acute and chronic pain and the brain changes affecting pain factors is important for finding pain treatment methods. The emergence and progress of non-invasive neuroimaging technology can help us better understand pain at the neural level. Recent developments in identifying brain-based biomarkers of pain through advances in advanced imaging can provide some foundations for predicting and detecting pain. For example, a neurologic pain signature (involving brain regions that receive nociceptive afferents) and a stimulus intensity-independent pain signature (involving brain regions that do not show increased activity in proportion to noxious stimulus intensity) were developed based on multivariate modeling to identify processes related to the pain experience. However, an accurate and comprehensive review of common neuroimaging techniques for evaluating pain is lacking. This paper reviews the mechanism, clinical application, reliability, strengths, and limitations of common neuroimaging techniques for assessing pain to promote our further understanding of pain.
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Affiliation(s)
- Jing Luo
- Department of Sport Rehabilitation, Xian Physical Education University, Xian, China
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China
| | - Hui-Qi Zhu
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China
- Department of Sport Rehabilitation, Shenyang Sport University, Shenyang, China
| | - Bo Gou
- Department of Sport Rehabilitation, Xian Physical Education University, Xian, China.
| | - Xue-Qiang Wang
- Department of Sport Rehabilitation, Shanghai University of Sport, Shanghai, China.
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13
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Lin WY, Hsieh JC, Lu CC, Ono Y. Altered metabolic connectivity between the amygdala and default mode network is related to pain perception in patients with cancer. Sci Rep 2022; 12:14105. [PMID: 35982228 PMCID: PMC9388574 DOI: 10.1038/s41598-022-18430-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 08/11/2022] [Indexed: 11/21/2022] Open
Abstract
We investigated the neural correlates for chronic cancer pain conditions by retrospectively analyzing whole brain regions on 18F-fluoro-2-deoxyglucose-positron emission tomography images acquired from 80 patients with head and neck squamous cell carcinoma and esophageal cancer. The patients were divided into three groups according to perceived pain severity and type of analgesic treatment, namely patients not under analgesic treatment because of no or minor pain, patients with good pain control under analgesic treatment, and patients with poor pain control despite analgesic treatment. Uncontrollable cancer pain enhanced the activity of the hippocampus, amygdala, inferior temporal gyrus, and temporal pole. Metabolic connectivity analysis further showed that amygdala co-activation with the hippocampus was reduced in the group with poor pain control and preserved in the groups with no or minor pain and good pain control. The increased although imbalanced activity of the medial temporal regions may represent poor pain control in patients with cancer. The number of patients who used anxiolytics was higher in the group with poor pain control, whereas the usage rates were comparable between the other two groups. Therefore, further studies should investigate the relationship between psychological conditions and pain in patients with cancer and analyze the resultant brain activity.Trial registration: This study was registered at clinicaltrials.gov on 9/3/20 (NCT04537845).
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Affiliation(s)
- Wen-Ying Lin
- grid.19188.390000 0004 0546 0241Department of Anesthesiology, National Taiwan University Cancer Center, Taipei, Taiwan ,grid.412094.a0000 0004 0572 7815Department of Anesthesiology, National Taiwan University Hospital, Taipei, Taiwan
| | - Jen-Chuen Hsieh
- grid.260539.b0000 0001 2059 7017Department of Biological Science and Technology, College of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
| | - Ching-Chu Lu
- grid.412094.a0000 0004 0572 7815Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Yumie Ono
- grid.411764.10000 0001 2106 7990School of Science and Technology, Meiji University, Kawasaki, Japan
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14
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Time-Dependent Changes in Protein Composition of Medial Prefrontal Cortex in Rats with Neuropathic Pain. Int J Mol Sci 2022; 23:ijms23020955. [PMID: 35055141 PMCID: PMC8781622 DOI: 10.3390/ijms23020955] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/10/2022] [Accepted: 01/14/2022] [Indexed: 01/03/2023] Open
Abstract
Chronic pain is associated with time-dependent structural and functional reorganization of the prefrontal cortex that may reflect adaptive pain compensatory and/or maladaptive pain-promoting mechanisms. However, the molecular underpinnings of these changes and whether there are time-dependent relationships to pain progression are not well characterized. In this study, we analyzed protein composition in the medial prefrontal cortex (mPFC) of rats at two timepoints after spinal nerve ligation (SNL) using two-dimensional gel electrophoresis (2D-ELFO) and liquid chromatography with tandem mass spectrometry (LC–MS/MS). SNL, but not sham-operated, rats developed persistent tactile allodynia and thermal hyperalgesia, confirming the presence of experimental neuropathic pain. Two weeks after SNL (early timepoint), we identified 11 proteins involved in signal transduction, protein transport, cell homeostasis, metabolism, and apoptosis, as well as heat-shock proteins and chaperones that were upregulated by more than 1.5-fold compared to the sham-operated rats. Interestingly, there were only four significantly altered proteins identified at 8 weeks after SNL (late timepoint). These findings demonstrate extensive time-dependent modifications of protein expression in the rat mPFC under a chronic neuropathic pain state that might underlie the evolution of chronic pain characterized by early pain-compensatory and later aberrant mechanisms.
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15
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Spinal and Cerebral Integration of Noxious Inputs in Left-handed Individuals. Brain Topogr 2021; 34:568-586. [PMID: 34338897 DOI: 10.1007/s10548-021-00864-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 07/23/2021] [Indexed: 10/20/2022]
Abstract
Some pain-related information is processed preferentially in the right cerebral hemisphere. Considering that functional lateralization can be affected by handedness, spinal and cerebral pain-related responses may be different between right- and left-handed individuals. Therefore, this study aimed to investigate the cortical and spinal mechanisms of nociceptive integration when nociceptive stimuli are applied to right -handed vs. left -handed individuals. The NFR, evoked potentials (ERP: P45, N100, P260), and event-related spectral perturbations (ERSP: theta, alpha, beta and gamma band oscillations) were compared between ten right-handed and ten left-handed participants. Pain was induced by transcutaneous electrical stimulation of the lower limbs and left upper limb. Stimulation intensity was adjusted individually in five counterbalanced conditions of 21 stimuli each: three unilateral (right lower limb, left lower limb, and left upper limb stimulation) and two bilateral conditions (right and left lower limbs, and the right lower limb and left upper limb stimulation). The amplitude of the NFR, ERP, ERSP, and pain ratings were compared between groups and conditions using a mixed ANOVA. A significant increase of responses was observed in bilateral compared with unilateral conditions for pain intensity, NFR amplitude, N100, theta oscillations, and gamma oscillations. However, these effects were not significantly different between right- and left-handed individuals. These results suggest that spinal and cerebral integration of bilateral nociceptive inputs is similar between right- and left-handed individuals. They also imply that pain-related responses measured in this study may be examined independently of handedness.
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16
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Current Understanding of the Involvement of the Insular Cortex in Neuropathic Pain: A Narrative Review. Int J Mol Sci 2021; 22:ijms22052648. [PMID: 33808020 PMCID: PMC7961886 DOI: 10.3390/ijms22052648] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/03/2021] [Accepted: 03/04/2021] [Indexed: 12/22/2022] Open
Abstract
Neuropathic pain is difficult to cure and is often accompanied by emotional and psychological changes. Exploring the mechanisms underlying neuropathic pain will help to identify a better treatment for this condition. The insular cortex is an important information integration center. Numerous imaging studies have documented increased activity of the insular cortex in the presence of neuropathic pain; however, the specific role of this region remains controversial. Early studies suggested that the insular lobe is mainly involved in the processing of the emotional motivation dimension of pain. However, increasing evidence suggests that the role of the insular cortex is more complex and may even be related to the neural plasticity, cognitive evaluation, and psychosocial aspects of neuropathic pain. These effects contribute not only to the development of neuropathic pain, but also to its comorbidity with neuropsychiatric diseases. In this review, we summarize the changes that occur in the insular cortex in the presence of neuropathic pain and analgesia, as well as the molecular mechanisms that may underlie these conditions. We also discuss potential sex-based differences in these processes. Further exploration of the involvement of the insular lobe will contribute to the development of new pharmacotherapy and psychotherapy treatments for neuropathic pain.
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17
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Xiao X, Ding M, Zhang YQ. Role of the Anterior Cingulate Cortex in Translational Pain Research. Neurosci Bull 2021; 37:405-422. [PMID: 33566301 PMCID: PMC7954910 DOI: 10.1007/s12264-020-00615-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/03/2020] [Indexed: 02/06/2023] Open
Abstract
As the most common symptomatic reason to seek medical consultation, pain is a complex experience that has been classified into different categories and stages. In pain processing, noxious stimuli may activate the anterior cingulate cortex (ACC). But the function of ACC in the different pain conditions is not well discussed. In this review, we elaborate the commonalities and differences from accumulated evidence by a variety of pain assays for physiological pain and pathological pain including inflammatory pain, neuropathic pain, and cancer pain in the ACC, and discuss the cellular receptors and signaling molecules from animal studies. We further summarize the ACC as a new central neuromodulation target for invasive and non-invasive stimulation techniques in clinical pain management. The comprehensive understanding of pain processing in the ACC may lead to bridging the gap in translational research between basic and clinical studies and to develop new therapies.
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Affiliation(s)
- Xiao Xiao
- Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, Ministry of Education; Institute of Science and Technology for Brain-Inspired Intelligence, Behavioral and Cognitive Neuroscience Center, Fudan University, Shanghai, 200433, China.
| | - Ming Ding
- Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, Ministry of Education; Institute of Science and Technology for Brain-Inspired Intelligence, Behavioral and Cognitive Neuroscience Center, Fudan University, Shanghai, 200433, China
| | - Yu-Qiu Zhang
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Translational Neuroscience, Jing'an District Centre Hospital of Shanghai, Institutes of Brain Science; Institute of Integrative Medicine, Fudan University, Shanghai, 200032, China.
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18
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Motor cortical excitability behavior in chronic spinal cord injury neuropathic pain individuals submitted to transcranial direct current stimulation-case reports. Spinal Cord Ser Cases 2020; 6:101. [PMID: 33208726 DOI: 10.1038/s41394-020-00355-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 10/06/2020] [Accepted: 10/17/2020] [Indexed: 11/09/2022] Open
Abstract
INTRODUCTION Increased excitability of the motor cortex through transcranial direct current stimulation (tDCS) has been described as a non-pharmacological strategy for the treatment of Spinal Cord Injury neuropathic pain (SCINP). It is also believed that the ability to enhance motor cortex excitability (MCE) could be impaired within chronic SCINP individuals. The following case reports describe the MCE behavior in individuals with chronic SCINP submitted to electrical non-invasive neuromodulation. CASE PRESENTATIONS This article reports 11 cases with chronic SCINP in which each individual was submitted to a 5-day pre-post MCE analysis in order to evaluate its behavior after the anodal tDCS sessions. All cases maintained ongoing pharmacological treatment. Four individuals have shown negative variation of the MCE, two of which reported pain intensity reduction. Three other individuals had MCE-positive variation along 5 days, from which only one reported a VAS 0.5 pain reduction after the 5th day of observation. The other four individuals did not present significant variation of the MCE. DISCUSSION The positive variation of MCE was significantly altered by adjunctive tDCS only in three individuals, though no clinically relevant reduction in pain intensity was reported among these participants. Key factors such as pain and injury duration, age, chronic medication use and underlying maladaptive neuroplasticity may influence responsiveness to brain stimulation within this population. These case reports try to add evidence for cautious recommendation of tDCS in chronic SCINP individuals and to the necessity of identifying groups of individuals that are most susceptible to neuromodulation.
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19
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Tinnermann A, Büchel C, Cohen-Adad J. Cortico-spinal imaging to study pain. Neuroimage 2020; 224:117439. [PMID: 33039624 DOI: 10.1016/j.neuroimage.2020.117439] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 09/21/2020] [Accepted: 10/01/2020] [Indexed: 12/15/2022] Open
Abstract
Functional magnetic resonance imaging of the brain has helped to reveal mechanisms of pain perception in health and disease. Recently, imaging approaches have been developed that allow recording neural activity simultaneously in the brain and in the spinal cord. These approaches offer the possibility to examine pain perception in the entire central pain system and in addition, to investigate cortico-spinal interactions during pain processing. Although cortico-spinal imaging is a promising technique, it bears challenges concerning data acquisition and data analysis strategies. In this review, we discuss studies that applied simultaneous imaging of the brain and spinal cord to explore central pain processing. Furthermore, we describe different MR-related acquisition techniques, summarize advantages and disadvantages of approaches that have been implemented so far and present software that has been specifically developed for the analysis of spinal fMRI data to address challenges of spinal data analysis.
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Affiliation(s)
- Alexandra Tinnermann
- Department for Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Max Planck School of Cognition, Leipzig, Germany.
| | - Christian Büchel
- Department for Systems Neuroscience, University Medical Center Hamburg-Eppendorf, Hamburg, Germany; Max Planck School of Cognition, Leipzig, Germany
| | - Julien Cohen-Adad
- NeuroPoly Lab, Institute of Biomedical Engineering, Polytechnique Montreal, Montreal, Quebec, Canada; Functional Neuroimaging Unit, CRIUGM, Université de Montréal, Montreal, Quebec, Canada.
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20
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Forstenpointner J, Berry D, Baron R, Borsook D. The cornucopia of central disinhibition pain - An evaluation of past and novel concepts. Neurobiol Dis 2020; 145:105041. [PMID: 32800994 DOI: 10.1016/j.nbd.2020.105041] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 07/18/2020] [Accepted: 08/08/2020] [Indexed: 12/12/2022] Open
Abstract
Central disinhibition (CD), as applied to pain, decreases thresholds of endogenous systems. This provokes onset of spontaneous or evoked pain in an individual beyond the ability of the nervous system to inhibit pain resulting from a disease or tissue damage. The original CD concept as proposed by Craig entails a shift from the lateral pain pathway (i.e. discriminative pain processing) towards the medial pain pathway (i.e. emotional pain processing), within an otherwise neurophysiological intact environment. In this review, the original CD concept as proposed by Craig is extended by the primary "nociceptive pathway damage - CD" concept and the secondary "central pathway set point - CD". Thereby, the original concept may be transferred into anatomical and psychological non-functional conditions. We provide examples for either primary or secondary CD concepts within different clinical etiologies as well as present surrogate models, which directly mimic the underlying pathophysiology (A-fiber block) or modulate the CD pathway excitability (thermal grill). The thermal grill has especially shown promising advancements, which may be useful to examine CD pathway activation in the future. Therefore, within this topical review, a systematic review on the thermal grill illusion is intended to stimulate future research. Finally, the authors review different mechanism-based treatment approaches to combat CD pain.
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Affiliation(s)
- Julia Forstenpointner
- Division of Neurological Pain Research and Therapy, Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3, 24105 Kiel, Germany; Center for Pain and the Brain, Boston Children's Hospital, Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA.
| | - Delany Berry
- Center for Pain and the Brain, Boston Children's Hospital, Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA
| | - Ralf Baron
- Division of Neurological Pain Research and Therapy, Department of Neurology, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3, 24105 Kiel, Germany
| | - David Borsook
- Center for Pain and the Brain, Boston Children's Hospital, Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, MA, USA
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21
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Di Pietro F, Lee B, Henderson LA. Altered resting activity patterns and connectivity in individuals with complex regional pain syndrome. Hum Brain Mapp 2020; 41:3781-3793. [PMID: 32510695 PMCID: PMC7416050 DOI: 10.1002/hbm.25087] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 05/20/2020] [Accepted: 05/20/2020] [Indexed: 12/20/2022] Open
Abstract
Complex regional pain syndrome (CRPS) is a chronic neuropathic pain disorder that typically occurs in the limbs, usually the upper limb. CRPS usually develops from a peripheral event but its maintenance relies on changes within the central nervous system. While functional abnormalities in the thalamus and primary somatosensory cortex (S1) of the brain are some of the most consistently reported brain findings in CRPS, the mechanisms are yet to be explored in full, not least of all how these two regions interact and how they might relate to clinical deficits, such as the commonly reported poor tactile acuity in this condition. This study recruited 15 upper‐limb CRPS subjects and 30 healthy controls and used functional magnetic resonance imaging (fMRI) to investigate infra‐slow oscillations (ISOs) in critical pain regions of the brain in CRPS. As hypothesised, we found CRPS was associated with increases in resting signal intensity ISOs (0.03–0.06 Hz) in the thalamus contralateral to the painful limb in CRPS subjects. Interestingly, there was no such difference between groups in S1, however CRPS subjects displayed stronger thalamo‐S1 functional connectivity than controls, and this was related to pain. As predicted, CRPS subjects displayed poor tactile acuity on the painful limb which, interestingly, was also related to thalamo‐S1 functional connectivity strength. Our findings provide novel evidence of altered patterns of resting activity and connectivity in CRPS which may underlie altered thalamocortical loop dynamics and the constant perception of pain.
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Affiliation(s)
- Flavia Di Pietro
- Department of Anatomy and Histology, Brain and Mind Centre, University of Sydney, Sydney, Australia.,School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin University, Perth, Australia
| | - Barbara Lee
- Department of Anatomy and Histology, Brain and Mind Centre, University of Sydney, Sydney, Australia
| | - Luke A Henderson
- Department of Anatomy and Histology, Brain and Mind Centre, University of Sydney, Sydney, Australia
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22
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De Groote S, Goudman L, Peeters R, Linderoth B, Van Schuerbeek P, Sunaert S, De Jaeger M, De Smedt A, De Andrés J, Moens M. The influence of High Dose Spinal Cord Stimulation on the descending pain modulatory system in patients with failed back surgery syndrome. NEUROIMAGE-CLINICAL 2019; 24:102087. [PMID: 31795057 PMCID: PMC6978217 DOI: 10.1016/j.nicl.2019.102087] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 11/04/2019] [Accepted: 11/09/2019] [Indexed: 12/22/2022]
Abstract
For the first time, the influence of HD-SCS on the descending pathways was tested. rsfMRI and functional connectivity were used to evaluate this a priori hypothesis. HD-SCS does influence the descending pain modulatory system.
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Affiliation(s)
- Sander De Groote
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, Brussels 1090, Belgium
| | - Lisa Goudman
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, Brussels 1090, Belgium; Pain in Motion International Research Group, www.paininmotion.be and Department of Physiotherapy, Human Physiology and Anatomy, Faculty of Physical Education & Physiotherapy, Vrije Universiteit Brussel, Brussels, Belgium
| | - Ronald Peeters
- Department of Radiology, Universitair Ziekenhuis Leuven, UZ Herestraat 49-bus 7003, Leuven 3000, Belgium
| | - Bengt Linderoth
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Peter Van Schuerbeek
- Department of Radiology, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, Brussels 1090, Belgium
| | - Stefan Sunaert
- Department of Radiology, Universitair Ziekenhuis Leuven, UZ Herestraat 49-bus 7003, Leuven 3000, Belgium
| | - Mats De Jaeger
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, Brussels 1090, Belgium
| | - Ann De Smedt
- Department of Neurology, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, Brussels 1090, Belgium
| | - José De Andrés
- Surgical Specialties Department Valencia University Medical School, Department of Anesthesiology Critical Care and Pain Management, General University Hospital, Valencia, Spain
| | - Maarten Moens
- Department of Neurosurgery, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, Brussels 1090, Belgium; Department of Radiology, Universitair Ziekenhuis Brussel, Laarbeeklaan 101, Brussels 1090, Belgium; Center for Neurosciences (C4N), Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, Brussels 1090, Belgium.
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23
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Gu D, Zhou M, Han C, Lei D, Xie S, Yuan Y, Ma T. Preoperative anxiety induces chronic postoperative pain by activating astrocytes in the anterior cingulate cortex region. REVISTA DA ASSOCIACAO MEDICA BRASILEIRA (1992) 2019; 65:1174-1180. [PMID: 31618333 DOI: 10.1590/1806-9282.65.9.1174] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 05/13/2019] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The study aims to explore the relationship between preoperative anxiety and chronic postoperative pain. METHODS A total of forty rats were divided into four groups, control, single-prolonged stress alone, Hysterectomy alone, and SPS+ Hysterectomy. The paw withdrawal mechanical thresholds (PWMT) were examined. qRT-PCR and western blotting assay were performed to detect the GFAP expression in astrocytes isolated from the anterior cingulate cortex (ACC) region. In addition, the long-term potentiation (LTP) in ACC was examined. RESULTS Rats in the SPS group or the Hysterectomy alone group had no significant effect on chronic pain formation, but SPS can significantly induce chronic pain after surgery. Astrocytes were still active, and the LTP was significantly increased three days after modeling in the SPS+Hysterectomy group. CONCLUSIONS anxiety can induce chronic pain by activating astrocytes in the ACC region.
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Affiliation(s)
- Damin Gu
- . Department of Anesthesiology, The Affiliated Yixing Hospital of Jiangsu University, Yixing, Jiangsu, China
| | - Minmin Zhou
- . Department of Anesthesiology, The Affiliated Yixing Hospital of Jiangsu University, Yixing, Jiangsu, China
| | - Chao Han
- . Department of Anesthesiology, The Affiliated Yixing Hospital of Jiangsu University, Yixing, Jiangsu, China
| | - Daoyun Lei
- . Department of Anesthesiology, The Affiliated Yixing Hospital of Jiangsu University, Yixing, Jiangsu, China
| | - Songhui Xie
- . Department of Anesthesiology, The Affiliated Yixing Hospital of Jiangsu University, Yixing, Jiangsu, China
| | - Yanbo Yuan
- . Department of Anesthesiology, The Affiliated Yixing Hospital of Jiangsu University, Yixing, Jiangsu, China
| | - Tieliang Ma
- . Department of Anesthesiology, The Affiliated Yixing Hospital of Jiangsu University, Yixing, Jiangsu, China
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Tozaki-Saitoh H, Tsuda M. Microglia-neuron interactions in the models of neuropathic pain. Biochem Pharmacol 2019; 169:113614. [PMID: 31445020 DOI: 10.1016/j.bcp.2019.08.016] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 08/19/2019] [Indexed: 12/31/2022]
Abstract
Chronic pain is a debilitating condition that often emerges as a clinical symptom of inflammatory diseases. It has therefore been widely accepted that the immune system critically contributes to the pathology of chronic pain. Microglia, a type of immune cell in the central nervous system, has attracted researchers' attention because in rodent models of neuropathic pain that develop strong mechanical and thermal hypersensitivity, histologically activated microglia are seen in the dorsal horn of spinal cord. Several kinds of cytokines are generated by damaged peripheral neurons and contribute to microglial activation at the distal site of the injury where damaged neurons send their projections. Microglia are known as key players in the surveillance of the local environment in the central nervous system and have a significant role of circuit remodeling by physical contact to synapses. Key molecules for the pathology of neuropathic pain exist in the activated microglia, but the factors driving pain-inducible microglial activation remain unclear. Therefore, to find the key molecules inducing activation of spinal microglia and to figure out the precise mechanism of how microglia modulate neuronal circuits in the spinal cord to form chronic pain state is a critical step for developing effective treatment of neuropathic pain.
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Affiliation(s)
- Hidetoshi Tozaki-Saitoh
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
| | - Makoto Tsuda
- Department of Life Innovation, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
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Hyakkoku K, Umeda N, Shimada S, Imai T, Morioka Y, Sakaguchi G, Hara H. Post-stroke pain caused by peripheral sensory hypersensitization after transient focal cerebral ischemia in rats. Brain Res 2019; 1715:35-40. [PMID: 30898673 DOI: 10.1016/j.brainres.2019.03.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 02/28/2019] [Accepted: 03/16/2019] [Indexed: 01/15/2023]
Abstract
The mechanisms underlying central post-stroke pain are not well understood and there is no satisfactory treatment. Here, in a rat model of stroke, we measured nociceptive threshold using current stimulation of primary afferent neurons in both hind paws. Male Wistar rats underwent middle cerebral artery occlusion (MCAO) for 50 min. Nociceptive thresholds for Aβ, Aδ and C fiber stimulation (at 2000, 250, and 5 Hz, respectively, using a Neurometer), and neurological deficits, were measured for 23 days after MCAO. Sensory thresholds in both hind paws were significantly lower in MCAO model rats than in control rats for 23 days after MCAO, with the greatest difference seen in Aδ fibers and the smallest in C fibers. Brain infarct area was measured histologically, and the correlation between neurological deficit and infarct size was examined. Neurological deficits were worse in animals with larger infarcts. Furthermore, correlations were observed between infarct size, neurological deficit, and sensory threshold of Aδ fibers 1 day after MCAO. These findings indicate that rats develop hyperalgesia after MCAO and that sensory abnormalities in Aδ fibers after cerebral ischemia may play an important role in post-stroke pain.
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Affiliation(s)
- Kana Hyakkoku
- Pain & Neuroscience, Discovery Research Laboratories for Core Therapeutic Areas, Shionogi & Co., Ltd., 1-1 Futaba-cho, 3-chome, Toyonaka, Osaka 561-0825, Japan.
| | - Nanae Umeda
- Shionogi TechnoAdvance Research & Co., Ltd., 1-1 Futaba-cho, 3-chome, Toyonaka, Osaka 561-0825, Japan
| | - Shinji Shimada
- Shionogi TechnoAdvance Research & Co., Ltd., 1-1 Futaba-cho, 3-chome, Toyonaka, Osaka 561-0825, Japan
| | - Takahiko Imai
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Digakunishi, Gifu 501-1196, Japan
| | - Yasuhide Morioka
- Pain & Neuroscience, Discovery Research Laboratories for Core Therapeutic Areas, Shionogi & Co., Ltd., 1-1 Futaba-cho, 3-chome, Toyonaka, Osaka 561-0825, Japan
| | - Gaku Sakaguchi
- Pain & Neuroscience, Discovery Research Laboratories for Core Therapeutic Areas, Shionogi & Co., Ltd., 1-1 Futaba-cho, 3-chome, Toyonaka, Osaka 561-0825, Japan
| | - Hideaki Hara
- Molecular Pharmacology, Department of Biofunctional Evaluation, Gifu Pharmaceutical University, 1-25-4 Digakunishi, Gifu 501-1196, Japan.
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Esmaeeli S, Murphy K, Swords GM, Ibrahim BA, Brown JW, Llano DA. Visual hallucinations, thalamocortical physiology and Lewy body disease: A review. Neurosci Biobehav Rev 2019; 103:337-351. [PMID: 31195000 DOI: 10.1016/j.neubiorev.2019.06.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2018] [Revised: 06/03/2019] [Accepted: 06/08/2019] [Indexed: 12/22/2022]
Abstract
One of the core diagnostic criteria for Dementia with Lewy Bodies (DLB) is the presence of visual hallucinations. The presence of hallucinations, along with fluctuations in the level of arousal and sleep disturbance, point to potential pathological mechanisms at the level of the thalamus. However, the potential role of thalamic dysfunction in DLB, particularly as it relates to the presence of formed visual hallucinations is not known. Here, we review the literature on the pathophysiology of DLB with respect to modern theories of thalamocortical function and attempt to derive an understanding of how such hallucinations arise. Based on the available literature, we propose that combined thalamic-thalamic reticular nucleus and thalamocortical pathology may explain the phenomenology of visual hallucinations in DLB. In particular, diminished α7 cholinergic activity in the thalamic reticular nucleus may critically disinhibit thalamocortical activity. Further, concentrated pathological changes within the posterior regions of the thalamus may explain the predilection for the hallucinations to be visual in nature.
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Affiliation(s)
- Shooka Esmaeeli
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Kathleen Murphy
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Gabriel M Swords
- University of Illinois at Chicago College of Medicine, Chicago, IL, United States
| | - Baher A Ibrahim
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Jeffrey W Brown
- University of Illinois at Chicago College of Medicine, Chicago, IL, United States
| | - Daniel A Llano
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Carle Neuroscience Institute, Urbana, IL, United States.
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Dopaminergic denervation using [123I]-FPCIT and pain in Parkinson’s disease: a correlation study. J Neural Transm (Vienna) 2019; 126:279-287. [DOI: 10.1007/s00702-019-01974-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Accepted: 01/21/2019] [Indexed: 10/27/2022]
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Ueda H, Neyama H, Sasaki K, Miyama C, Iwamoto R. Lysophosphatidic acid LPA 1 and LPA 3 receptors play roles in the maintenance of late tissue plasminogen activator-induced central poststroke pain in mice. NEUROBIOLOGY OF PAIN (CAMBRIDGE, MASS.) 2019; 5:100020. [PMID: 31194070 PMCID: PMC6550111 DOI: 10.1016/j.ynpai.2018.07.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/17/2018] [Accepted: 07/19/2018] [Indexed: 11/17/2022]
Abstract
We developed a mouse model for central post-stroke pain (CPSP), a centrally-originated neuropathic pain (NeuP). In this mode, mice were first injected with Rose Bengal, followed by photo-irradiation of left middle cerebral artery (MCA) to generate thrombosis. Although the MCA thrombosis was soon dissolved, the reduced blood flow remained for more than 24 h due to subsequent occlusion of microvessels. This photochemically induced thrombosis (PIT) model showed a hypersensitivity to the electrical stimulation of both sides of paw, but did not show any abnormal pain in popular thermal or mechanical nociception tests. When tissue-type plasminogen activator (tPA) was injected 6 h after the PIT stress, tPA-dependent hypersensitivity to the electrical paw stimulation and stable thermal and mechanical hyperalgesia on both sides for more than 17 or 18 days after the PIT treatment. These hyperalgesic effects were abolished in lysophosphatidic acid receptor 1 (LPA1)- and lysophosphatidic acid receptor 3 (LPA3)-deficient mice. When Ki-16425, an LPA1 and LPA3 antagonist was treated twice daily for 6 days consecutively, the thermal and mechanical hyperalgesia at day 17 and 18 were significantly reversed. The liquid chromatography-mass spectrometry (LC-MS/MS) analysis revealed that there is a significant increase in several species of LPA molecules in somatosensory S-I and medial dorsal thalamus (MD), but not in striatum or ventroposterior thalamus. All these results suggest that LPA1 and LPA3 signaling play key roles in the development and maintenance of CPSP.
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Key Words
- CPSP, central post-stroke pain
- Central poststroke pain
- DMSO, dimethyl sulfoxide
- EPW, electrical stimulation-induced paw withdrawal
- HE, Hematoxylin and Eosin
- LC–MS/MS
- LC–MS/MS, liquid chromatography–mass spectrometry
- LPA1, lysophosphatidic acid receptor 1
- LPA1-KO, LPA1-deficient
- LPA3, lysophosphatidic acid receptor 3
- Lysophosphatidic acid
- MCA, middle cerebral artery
- MD, medial dorsal thalamus
- MRM, multiple reaction monitoring
- NeuP, neuropathic pain
- PFA, paraformaldehyde
- PIT, photochemically induced thrombosis
- PWL, paw withdrawal latency
- Photochemically induced thrombosis
- RB, Rose Bengal
- S-I, sensory cortex
- TTC, 2,3,5-triphenyltetrazolium chloride
- i.v., intravenously
- pSNL, partial sciatic nerve ligation
- tMCAO, transient middle cerebral artery occlusion
- tPA
- tPA, tissue-type plasminogen activator
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Affiliation(s)
- Hiroshi Ueda
- Department of Pharmacology and Therapeutic Innovation, Nagasaki University, Institute of Biomedical Sciences, 1-14 Bunkyo-machi, Nagasaki 852-8521, Japan
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Lin WY, Chu WH, Chao THH, Sun WZ, Yen CT. Longitudinal FDG-PET scan study of brain changes in mice with cancer-induced bone pain and after morphine analgesia. Mol Pain 2019; 15:1744806919841194. [PMID: 30868934 PMCID: PMC6492350 DOI: 10.1177/1744806919841194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 02/14/2019] [Accepted: 02/20/2019] [Indexed: 01/21/2023] Open
Abstract
Morphine is the most commonly used drug for treating physical and psychological suffering caused by advanced cancer. Although morphine is known to elicit multiple supraspinal analgesic effects, its behavioral correlates with respect to the whole-brain metabolic activity during cancer-induced bone pain have not been elucidated. We injected 4T1 mouse breast cancer cells into the left femur bone marrow cavity of BALB/c mice. All mice developed limb use deficits, mechanical allodynia, and hypersensitivity to cold, which were effectively suppressed with morphine. Serial 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) was performed for each mouse before cancer induction (0 day), after cancer-induced bone pain was established (14 days), and during effective morphine treatment (16 days). The longitudinal FDG-PET imaging analysis demonstrated that cancer-induced bone pain increased glucose uptake in the insular cortex and hypothalamus and decreased the activity of the retrosplenial cortex. Morphine reversed the activation of the insular cortex and hypothalamus. Furthermore, morphine activated the amygdala and rostral ventromedial medulla and suppressed the activity of anterior cingulate cortex. Our findings of hypothalamic and insular cortical activation support the hypothesis that cancer-induced bone pain has strong inflammatory and affective components in freely moving animals. Morphine may provide descending inhibitory and facilitatory actions in the treatment of cancer-induced bone pain in a clinical setting.
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Affiliation(s)
- Wen-Ying Lin
- Department of Life Science, National Taiwan University,
Taipei
- Department of Anesthesiology, National Taiwan University
Hospital, Taipei
- National Taiwan University Cancer Center, National Taiwan
University College of Medicine, Taipei
| | - Wen-Hua Chu
- Department of Life Science, National Taiwan University,
Taipei
| | | | - Wen-Zen Sun
- Department of Anesthesiology, National Taiwan University
Hospital, Taipei
| | - Chen-Tung Yen
- Department of Life Science, National Taiwan University,
Taipei
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30
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Kang D, McAuley JH, Kassem MS, Gatt JM, Gustin SM. What does the grey matter decrease in the medial prefrontal cortex reflect in people with chronic pain? Eur J Pain 2018; 23:203-219. [PMID: 30101509 DOI: 10.1002/ejp.1304] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 08/05/2018] [Accepted: 08/07/2018] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND OBJECTIVE Alterations in the grey matter volume of several brain regions have been reported in people with chronic pain. The most consistent observation is a decrease in grey matter volume in the medial prefrontal cortex. These findings are important as the medial prefrontal cortex plays a critical role in emotional and cognitive processing in chronic pain. Although a logical cause of grey matter volume decrease may be neurodegeneration, this is not supported by the current evidence. Therefore, the purpose of this review was to evaluate the existing literature to unravel what the decrease in medial prefrontal cortex grey matter volume in people with chronic pain may represent on a biochemical and cellular level. DATABASES AND DATA TREATMENT A literature search for this topical review was conducted using PubMed and SCOPUS library. Search terms included chronic pain, pain, medial prefrontal cortex, anterior cingulate cortex, grey matter, neurochemistry, spectroscopy, magnetic resonance imaging, positron emission tomography, dendrite, neurodegeneration, glia, astrocyte, microglia, neurotransmitter, glutamate, GABA and different combinations of these terms. RESULTS Adopting a stress model of chronic pain, two major pathways are proposed that contribute to grey matter volume decrease in the medial prefrontal cortex: (a) changes in dendritic morphology as a result of hypothalamic-pituitary axis dysfunction and (b) neurotransmitter dysregulation, specifically glutamate and γ-Aminobutyric acid, which affects local microvasculature. CONCLUSION Our model proposes new mechanisms in chronic pain pathophysiology responsible for mPFC grey matter loss as alternatives to neurodegeneration. SIGNIFICANCE It is unclear what the decrease in medial prefrontal cortex grey matter volume represents in chronic pain. The most attractive reason is neurodegeneration. However, there is no evidence to support this. Our review reveals nondegenerative causes of decreased medial prefrontal grey matter to guide future research into chronic pain pathophysiology.
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Affiliation(s)
- David Kang
- Neuroscience Research Australia, Sydney, NSW, Australia.,UNSW Medicine, UNSW Sydney, Sydney, NSW, Australia
| | - James H McAuley
- Neuroscience Research Australia, Sydney, NSW, Australia.,UNSW Medicine, UNSW Sydney, Sydney, NSW, Australia
| | | | - Justine M Gatt
- Neuroscience Research Australia, Sydney, NSW, Australia.,School of Psychology, UNSW Sydney, Sydney, NSW, Australia
| | - Sylvia M Gustin
- Neuroscience Research Australia, Sydney, NSW, Australia.,School of Psychology, UNSW Sydney, Sydney, NSW, Australia
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Acute and Chronic Pain Processing in the Thalamocortical System of Humans and Animal Models. Neuroscience 2018; 387:58-71. [DOI: 10.1016/j.neuroscience.2017.09.042] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Revised: 08/24/2017] [Accepted: 09/24/2017] [Indexed: 02/07/2023]
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Walton DM, Elliott JM. A new clinical model for facilitating the development of pattern recognition skills in clinical pain assessment. Musculoskelet Sci Pract 2018; 36:17-24. [PMID: 29669311 DOI: 10.1016/j.msksp.2018.03.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Revised: 03/10/2018] [Accepted: 03/17/2018] [Indexed: 11/16/2022]
Abstract
Common, enigmatic musculoskeletal conditions such as whiplash-associated disorder, myofascial pain syndrome, low back pain, headache, fibromyalgia, osteoarthritis, and rotator cuff pathology, account for significant social, economic, and personal burdens on a global scale. Despite their primacy (and shared sequelae) there remains a paucity of available and effective management options for patients with both acute and chronic conditions. Establishing an accurate prognostic or diagnostic profile on a patient-by-patient basis can challenge the insight of both novice and expert clinicians. Questions remain on how and when to choose the right tool(s), at the right time(s), for the right patient(s), for the right problem(s). The aim of this paper is to introduce a new clinical reasoning framework that is simple in presentation but allows interpretation of complex clinical patterns, and is adaptable across patient populations with acute or chronic, traumatic or non-traumatic pain. The concepts of clinical phenotyping (e.g. identifying observable characteristics of an individual resulting from the interaction of his/her genotype and their environment) and triangulation serve as the foundation for this framework. Based on our own clinical and research programs, we present these concepts using two patient cases; a) whiplash-associated disorder (WAD) following a motor vehicle collision and b) mechanical low back pain.
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Affiliation(s)
- David M Walton
- Faculty of Health Science, Western University Canada, Canada.
| | - James M Elliott
- Faculty of Health Sciences, The University of Sydney, and the Kolling Institute, Royal North Shore Hospital, NSW, Australia.
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Migraine Pain Location and Measures of Healthcare Use and Distress: An Observational Study. Pain Res Manag 2018; 2018:6157982. [PMID: 29973968 PMCID: PMC6008805 DOI: 10.1155/2018/6157982] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2017] [Revised: 03/06/2018] [Accepted: 04/05/2018] [Indexed: 11/17/2022]
Abstract
Introduction Lateralized pain is a core diagnostic feature of migraine. In previous research, left-sided spinal pain was more frequent and associated with greater emotional distress and healthcare use than right-sided pain. We hypothesized therefore that patients with left-sided head pain might experience higher levels of distress or healthcare use than those with right-sided or bilateral pain. Methods Medical record information was extracted for 477 randomly selected patients with migraine seen in 2011 in a tertiary headache clinic. This included demographic data, pain location, handedness, comorbid psychiatric diagnoses, medical and emergency department visits, and use of selected headache medications. Results and Discussion Two hundred twenty-eight of four hundred seventy-seven (47.8%) patients reported lateralized pain, of which 107 (47.9%) patients were right sided compared with 65 (28.5%) left-sided patients (p=0.001), while 56 (24.5%) reported unilateral pain with no side predominance. Contrary to expectations, with the exception of self-reported posttraumatic stress disorder, there were no statistically significant differences between left and right in measures of psychiatric distress, emergency department visits, or healthcare use. Conclusion Although unilateral pain location can be helpful in making a migraine diagnosis, it does not appear to have additional clinical implications. Additionally, its absence does not rule out a diagnosis of migraine since more than half of migraineurs have bilateral head pain.
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Quantitative sensory testing profiles in children, adolescents and young adults (6-20 years) with cerebral palsy: Hints for a neuropathic genesis of pain syndromes. Eur J Paediatr Neurol 2018; 22:470-481. [PMID: 29337004 DOI: 10.1016/j.ejpn.2017.12.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 09/20/2017] [Accepted: 12/19/2017] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Many patients with cerebral palsy (CP) suffer chronic pain as one of the most limiting factors in their quality of life. In CP patients, pain mechanisms are not well understood, and pain therapy remains a challenge. Quantitative sensory testing (QST) might provide unique information about the functional status of the somatosensory system and therefore better guide pain treatment. OBJECTIVES To understand better the underlying pain mechanisms in pediatric CP patients, we aimed to assess clinical and pain parameters, as well as QST profiles, which were matched to the patients' cerebral imaging pathology. PATIENTS AND METHODS Thirty CP patients aged 6-20 years old (mean age 12 years) without intellectual impairment underwent standardized assessments of QST. Cerebral imaging was reassessed. QST results were compared to age- and sex-matched controls (multiple linear regression; Fisher's exact test; linear correlation analysis). RESULTS CP patients were less sensitive to all mechanical and thermal stimuli than healthy controls but more sensitive to all mechanical pain stimuli (each p < 0.001). Fifty percent of CP patients showed a combination of mechanical hypoesthesia, thermal hypoesthesia and mechanical hyperalgesia; 67% of CP patients had periventricular leukomalacia (PVL), which was correlated with mechanic (r = 0.661; p < 0.001) and thermal (r = 0.624; p = 0.001) hypoesthesia. CONCLUSION The combination of mechanical hypoesthesia, thermal hypoesthesia and mechanical hyperalgesia in our CP patients implicates lemniscal and extralemniscal neuron dysfunction in the thalamus region, likely due to PVL. We suspect that extralemniscal tracts are involved in the original of pain in our CP patients, as in adults.
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Alshelh Z, Di Pietro F, Mills EP, Vickers ER, Peck CC, Murray GM, Henderson LA. Altered regional brain T2 relaxation times in individuals with chronic orofacial neuropathic pain. NEUROIMAGE-CLINICAL 2018; 19:167-173. [PMID: 30035014 PMCID: PMC6051476 DOI: 10.1016/j.nicl.2018.04.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 04/10/2018] [Accepted: 04/12/2018] [Indexed: 01/12/2023]
Abstract
The neural mechanisms underlying the development and maintenance of chronic pain following nerve injury remain unclear. There is growing evidence that chronic neuropathic pain is associated with altered thalamic firing patterns, thalamocortical dysrhythmia and altered infra-slow oscillations in ascending pain pathways. Preclinical and post-mortem human studies have revealed that neuropathic pain is associated with prolonged astrocyte activation in the dorsal horn and we have suggested that this may result in altered gliotransmission, which results in altered resting neural rhythm in the ascending pain pathway. Evidence of astrocyte activation above the level of the dorsal horn in living humans is lacking and direct measurement of astrocyte activation in living humans is not possible, however, there is evidence that regional alterations in T2 relaxation times are indicative of astrogliosis. The aim of this study was to use T2 relaxometry to explore regional brain anatomy of the ascending pain pathway in individuals with chronic orofacial neuropathic pain. We found that in individuals with trigeminal neuropathic pain, decreases in T2 relaxation times occurred in the region of the spinal trigeminal nucleus and primary somatosensory cortex, as well as in higher order processing regions such as the dorsolateral prefrontal, cingulate and hippocampal/parahippocampal cortices. We speculate that these regional changes in T2 relaxation times reflect prolonged astrocyte activation, which results in altered brain rhythm and ultimately the constant perception of pain. Blocking prolonged astrocyte activation may be effective in preventing and even reversing the development of chronic pain following neural injury. Reduced T2 relaxation time in the ascending pain pathway in chronic orofacial pain. These reductions may be associated with astrogliosis. Increase astrocyte activity associated with chronic orofacial pain.
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Affiliation(s)
- Z Alshelh
- Department of Anatomy and Histology, Sydney Medical School, University of Sydney, 2006, Australia
| | - F Di Pietro
- Department of Anatomy and Histology, Sydney Medical School, University of Sydney, 2006, Australia
| | - E P Mills
- Department of Anatomy and Histology, Sydney Medical School, University of Sydney, 2006, Australia
| | - E R Vickers
- Department of Anatomy and Histology, Sydney Medical School, University of Sydney, 2006, Australia
| | - C C Peck
- Faculty of Dentistry, University of Sydney, 2006, Australia
| | - G M Murray
- Faculty of Dentistry, University of Sydney, 2006, Australia
| | - L A Henderson
- Department of Anatomy and Histology, Sydney Medical School, University of Sydney, 2006, Australia.
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Rosenow JM. Anatomy of the Nervous System. Neuromodulation 2018. [DOI: 10.1016/b978-0-12-805353-9.00003-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Peng K, Steele SC, Becerra L, Borsook D. Brodmann area 10: Collating, integrating and high level processing of nociception and pain. Prog Neurobiol 2017; 161:1-22. [PMID: 29199137 DOI: 10.1016/j.pneurobio.2017.11.004] [Citation(s) in RCA: 76] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 11/16/2017] [Accepted: 11/28/2017] [Indexed: 02/08/2023]
Abstract
Multiple frontal cortical brain regions have emerged as being important in pain processing, whether it be integrative, sensory, cognitive, or emotional. One such region, Brodmann Area 10 (BA 10), is the largest frontal brain region that has been shown to be involved in a wide variety of functions including risk and decision making, odor evaluation, reward and conflict, pain, and working memory. BA 10, also known as the anterior prefrontal cortex, frontopolar prefrontal cortex or rostral prefrontal cortex, is comprised of at least two cytoarchitectonic sub-regions, medial and lateral. To date, the explicit role of BA 10 in the processing of pain hasn't been fully elucidated. In this paper, we first review the anatomical pathways and functional connectivity of BA 10. Numerous functional imaging studies of experimental or clinical pain have also reported brain activations and/or deactivations in BA 10 in response to painful events. The evidence suggests that BA 10 may play a critical role in the collation, integration and high-level processing of nociception and pain, but also reveals possible functional distinctions between the subregions of BA 10 in this process.
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Affiliation(s)
- Ke Peng
- Center for Pain and the Brain, Harvard Medical School, Boston, MA, United States; Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, MA, United States; Department of Psychiatry and Radiology, Massachusetts General Hospital, Charlestown, MA, United States.
| | - Sarah C Steele
- Center for Pain and the Brain, Harvard Medical School, Boston, MA, United States; Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, MA, United States; Department of Psychiatry and Radiology, Massachusetts General Hospital, Charlestown, MA, United States
| | - Lino Becerra
- Center for Pain and the Brain, Harvard Medical School, Boston, MA, United States; Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, MA, United States; Department of Psychiatry and Radiology, Massachusetts General Hospital, Charlestown, MA, United States; Department of Psychiatry, Mclean Hospital, Belmont, MA, United States
| | - David Borsook
- Center for Pain and the Brain, Harvard Medical School, Boston, MA, United States; Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital, Boston, MA, United States; Department of Psychiatry and Radiology, Massachusetts General Hospital, Charlestown, MA, United States; Department of Psychiatry, Mclean Hospital, Belmont, MA, United States
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Cordeiro Matos S, Zamfir M, Longo G, Ribeiro-da-Silva A, Séguéla P. Noradrenergic fiber sprouting and altered transduction in neuropathic prefrontal cortex. Brain Struct Funct 2017; 223:1149-1164. [PMID: 29094305 DOI: 10.1007/s00429-017-1543-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 10/19/2017] [Indexed: 12/22/2022]
Abstract
Functional changes in hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels have been shown to contribute to medial prefrontal (mPFC) hyperexcitability after peripheral nerve injury. A reduction in the open probability of these neuronal channels might be relevant since this can enhance membrane input resistance and synaptic summation. However, the molecular mechanisms underlying neuropathy-associated alterations in HCN channel activity remain elusive. Using the spared nerve injury model of neuropathic pain in Long-Evans rats, we first discovered a significant increase in noradrenergic innervation within the mPFC of nerve-injured compared to control animals. Patch-clamp recordings in layer II/III pyramidal neurons of the mPFC revealed that adrenoceptors, primarily the α2 subtype, can modulate the voltage-dependent activation of HCN channels and the abnormal prefrontal excitability following peripheral neuropathy. Additionally, microinfusions of the α2 adrenoceptor agonist clonidine in the mPFC of neuropathic rats provided analgesic effects, indicating the behavioral significance for this noradrenergic pathway in manifestations of the chronic pain state. Taken together, our results provide insights into the role of cortical catecholaminergic neuromodulation in neuropathic pain and suggest that altered noradrenergic transduction may play a major role in the HCN channel dysfunction and pyramidal hyperactivity observed in several chronic pain conditions.
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Affiliation(s)
- Steven Cordeiro Matos
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, 3801 University, Montreal, QC, H3A 2B4, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, H3A 0G1, Canada
| | - Maria Zamfir
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, 3801 University, Montreal, QC, H3A 2B4, Canada.,Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, H3A 0G1, Canada
| | - Geraldine Longo
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, H3A 0G1, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Alfredo Ribeiro-da-Silva
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, H3A 0G1, Canada.,Department of Pharmacology and Therapeutics, McGill University, Montreal, QC, H3G 1Y6, Canada
| | - Philippe Séguéla
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, 3801 University, Montreal, QC, H3A 2B4, Canada. .,Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, H3A 0G1, Canada.
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Jarrahi B, Martucci KT, Nilakantan AS, Mackey S. Investigating the BOLD spectral power of the intrinsic connectivity networks in fibromyalgia patients: A resting-state fMRI study. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2017; 2017:497-500. [PMID: 29059918 DOI: 10.1109/embc.2017.8036870] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Recent advances in multivariate statistical analysis of blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) have provided novel insights into the network organization of the human brain. Here, we applied group independent component analysis, a well-established approach for detecting brain intrinsic connectivity networks, to examine the spontaneous BOLD fluctuations in patients with fibromyalgia and healthy controls before and after exposure to a stressor. The BOLD spectral power characteristics of component time courses were calculated using the fast Fourier transform (FFT) algorithm, and group comparison was performed at six frequency bins between 0 and 0.24 Hz at 0.04 Hz intervals. Relative to controls, patients with fibromyalgia displayed significant BOLD spectral power differences in the default-mode, salience, and subcortical networks at the baseline level (PBon ferroni-corrected <; 0.05). Multivariate analysis of covariance (MANCOVA) further revealed significant effects of the cold water temperature, and pain rating on the spectral power of the sensorimotor, salience, and prefrontal networks, while the diagnosis of fibromyalgia influenced the BOLD spectral power of the salience and subcortical networks (PFDR-corrected <; 0.05). Since the BOLD spectral power reflects the degree of fluctuations within a network, future studies of the correlation between BOLD spectral power and pain processing can cast additional light on the nature of the central nervous system dysfunction in patients with chronic pain syndromes.
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Mukaihara K, Hasegawa-Moriyama M, Kanmura Y. Contralateral cerebral hemoglobin oxygen saturation changes in patients undergoing thoracotomy with general anesthesia with or without paravertebral block: a randomized controlled trial. J Anesth 2017; 31:829-836. [DOI: 10.1007/s00540-017-2402-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 08/10/2017] [Indexed: 01/06/2023]
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Kim JH, Choi SH, Jang JH, Lee DH, Lee KJ, Lee WJ, Moon JY, Kim YC, Kang DH. Impaired insula functional connectivity associated with persistent pain perception in patients with complex regional pain syndrome. PLoS One 2017; 12:e0180479. [PMID: 28692702 PMCID: PMC5503260 DOI: 10.1371/journal.pone.0180479] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 06/15/2017] [Indexed: 11/18/2022] Open
Abstract
Given that the insula plays a contributory role in the perception of chronic pain, we examined the resting-state functional connectivity between the insular cortex and other brain regions to investigate neural underpinnings of persisting perception of background pain in patients with complex regional pain syndrome (CRPS). A total of 25 patients with CRPS and 25 matched healthy controls underwent functional magnetic resonance imaging at rest. With the anterior and posterior insular cortices as seed regions, we compared the strength of the resting-state functional connectivity between the two groups. Functional connectivity between the anterior and posterior insular cortices and the postcentral and inferior frontal gyri, cingulate cortices was reduced in patients with CRPS compared with controls. Additionally, greater reductions in functional connectivity between the anterior insula and right postcentral gyrus were associated with more severe sensory pain in patients with CRPS (short-form McGill Pain Questionnaire sensory subscores, r = -.517, P = .023). The present results imply a possible role of the insula in aberrant processing of pain information in patients with CRPS. The findings suggest that a functional derangement of the connection between one of the somatosensory cortical functions of perception and one of the insular functions of awareness can play a significant role in the persistent experience of regional pain that is not confined to a specific nerve territory.
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Affiliation(s)
- Jae-Hun Kim
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
| | - Soo-Hee Choi
- Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Psychiatry and Institute of Human Behavioral Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Joon Hwan Jang
- Department of Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Do-Hyeong Lee
- Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Kyung-Jun Lee
- Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Won Joon Lee
- Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jee Youn Moon
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Yong Chul Kim
- Department of Anesthesiology and Pain Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Do-Hyung Kang
- Department of Psychiatry, Seoul National University Hospital, Seoul, Republic of Korea
- Department of Psychiatry and Institute of Human Behavioral Sciences, Seoul National University College of Medicine, Seoul, Republic of Korea
- * E-mail:
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42
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Miyamoto K, Kume K, Ohsawa M. Role of microglia in mechanical allodynia in the anterior cingulate cortex. J Pharmacol Sci 2017; 134:158-165. [PMID: 28669596 DOI: 10.1016/j.jphs.2017.05.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Revised: 05/12/2017] [Accepted: 05/22/2017] [Indexed: 01/06/2023] Open
Abstract
Plastic changes that increase nociceptive transmission are observed in several brain regions under conditions of chronic pain. Synaptic plasticity in the anterior cingulate cortex (ACC) is particularly associated with neuropathic pain. Glial cells are considered candidates for the modulation of neural plastic changes in the central nervous system. In this study, we aimed to investigate the role of ACC glial cells in the development of neuropathic pain. First, we examined the expression of glial cells in the ACC of nerve-ligated mice. The expression of astrocytes and microglia was increased in the ACC of nerve-ligated mice, which was reversed by intracerebroventricular (i.c.v) treatment with the microglia inhibitor minocycline. Then, we examined the effect of minocycline on mechanical allodynia in nerve-ligated mice. I.c.v. and intra-ACC treatment with minocycline partially inhibited mechanical allodynia in the nerve-ligated mice. The expression of phosphorylated alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluR1 subunit at Ser831, but not at Ser845, was increased in the ACC of the nerve-ligated mice compared to sham-operated mice, which was attenuated by minocycline administration. These results suggest that the activation of microglia in the ACC is involved in the development of hyperalgesia in mice with neuropathic pain.
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Affiliation(s)
- Keisuke Miyamoto
- Department of Neuropharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Kazuhiko Kume
- Department of Neuropharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan
| | - Masahiro Ohsawa
- Department of Neuropharmacology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya 467-8603, Japan.
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43
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Genaro K, Fabris D, Arantes ALF, Zuardi AW, Crippa JAS, Prado WA. Cannabidiol Is a Potential Therapeutic for the Affective-Motivational Dimension of Incision Pain in Rats. Front Pharmacol 2017; 8:391. [PMID: 28680401 PMCID: PMC5478794 DOI: 10.3389/fphar.2017.00391] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/06/2017] [Indexed: 12/11/2022] Open
Abstract
Background: Pain involves different brain regions and is critically determined by emotional processing. Among other areas, the rostral anterior cingulate cortex (rACC) is implicated in the processing of affective pain. Drugs that interfere with the endocannabinoid system are alternatives for the management of clinical pain. Cannabidiol (CBD), a phytocannabinoid found in Cannabis sativa, has been utilized in preclinical and clinical studies for the treatment of pain. Herein, we evaluate the effects of CBD, injected either systemically or locally into the rACC, on mechanical allodynia in a postoperative pain model and on the negative reinforcement produced by relief of spontaneous incision pain. Additionally, we explored whether CBD underlies the reward of pain relief after systemic or rACC injection. Methods and Results: Male Wistar rats were submitted to a model of incision pain. All rats had mechanical allodynia, which was less intense after intraperitoneal CBD (3 and 10 mg/kg). Conditioned place preference (CPP) paradigm was used to assess negative reinforcement. Intraperitoneal CBD (1 and 3 mg/kg) inverted the CPP produced by peripheral nerve block even at doses that do not change mechanical allodynia. CBD (10 to 40 nmol/0.25 μL) injected into the rACC reduced mechanical allodynia in a dose-dependent manner. CBD (5 nmol/0.25 μL) did not change mechanical allodynia, but reduced peripheral nerve block-induced CPP, and the higher doses inverted the CPP. Additionally, CBD injected systemically or into the rACC at doses that did not change the incision pain evoked by mechanical stimulation significantly produced CPP by itself. Therefore, a non-rewarding dose of CBD in sham-incised rats becomes rewarding in incised rats, presumably because of pain relief or reduction of pain aversiveness. Conclusion: The study provides evidence that CBD influences different dimensions of the response of rats to a surgical incision, and the results establish the rACC as a brain area from which CBD evokes antinociceptive effects in a manner similar to the systemic administration of CBD. In addition, the study gives further support to the notion that the sensorial and affective dimensions of pain may be differentially modulated by CBD.
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Affiliation(s)
- Karina Genaro
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloSão Paulo, Brazil.,Department of Psychology and Education, Faculty of Phylosophy, Science and Language Studies of Ribeirão Preto, University of São PauloSão Paulo, Brazil
| | - Débora Fabris
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloSão Paulo, Brazil.,Department of Psychology and Education, Faculty of Phylosophy, Science and Language Studies of Ribeirão Preto, University of São PauloSão Paulo, Brazil
| | - Ana L F Arantes
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloSão Paulo, Brazil.,Department of Psychology and Education, Faculty of Phylosophy, Science and Language Studies of Ribeirão Preto, University of São PauloSão Paulo, Brazil
| | - Antônio W Zuardi
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloSão Paulo, Brazil.,National Institute of Science and Technology for Translational Medicine, Conselho Nacional de Desenvolvimento Cientifico e TecnologicoBrasília, Brazil
| | - José A S Crippa
- Department of Neuroscience and Behavioral Sciences, Ribeirão Preto Medical School, University of São PauloSão Paulo, Brazil.,National Institute of Science and Technology for Translational Medicine, Conselho Nacional de Desenvolvimento Cientifico e TecnologicoBrasília, Brazil
| | - Wiliam A Prado
- Department of Psychology and Education, Faculty of Phylosophy, Science and Language Studies of Ribeirão Preto, University of São PauloSão Paulo, Brazil.,Department of Pharmacology, Ribeirão Preto Medical School, University of São PauloSão Paulo, Brazil
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Zhao Z, Huang T, Tang C, Ni K, Pan X, Yan C, Fan X, Xu D, Luo Y. Altered resting-state intra- and inter- network functional connectivity in patients with persistent somatoform pain disorder. PLoS One 2017; 12:e0176494. [PMID: 28453543 PMCID: PMC5409184 DOI: 10.1371/journal.pone.0176494] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 04/11/2017] [Indexed: 11/18/2022] Open
Abstract
Patients with persistent somatoform pain disorder (PSPD) usually experience various functional impairments in pain, emotion, and cognition, which cannot be fully explained by a physiological process or a physical disorder. However, it is still not clear for the mechanism underlying the pathogenesis of PSPD. The present study aimed to explore the intra- and inter-network functional connectivity (FC) differences between PSPD patients and healthy controls (HCs). Functional magnetic resonance imaging (fMRI) was performed in 13 PSPD patients and 23 age- and gender-matched HCs. We used independent component analysis on resting-state fMRI data to calculate intra- and inter-network FCs, and we used the two-sample t-test to detect the FC differences between groups. Spearman correlation analysis was employed to evaluate the correlations between FCs and clinical assessments. As compared to HCs, PSPD patients showed decreased coactivations in the right superior temporal gyrus within the anterior default-mode network and the anterior cingulate cortex within the salience network, and increased coactivations in the bilateral supplementary motor areas within the sensorimotor network and both the left posterior cingulate cortex and the medial prefrontal cortex within the anterior default-mode network. In addition, we found that the PSPD patients showed decreased FNCs between sensorimotor network and audio network as well as visual network, between default-mode network and executive control network as well as audio network and between salience network and executive control network as well as right frontoparietal network, and increased FNCs between sensorimotor network and left frontoparietal network, salience network as well as cerebellum network, which were negatively correlated with the clinical assessments in PSPD patients. Our findings suggest that PSPD patients experience large-scale reorganization at the level of the functional networks, which suggests a possible mechanism underlying the pathogenesis of PSPD.
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Affiliation(s)
- Zhiyong Zhao
- MOE & Shanghai Key Laboratory of Brain Functional Genomics (East China Normal University), Institute of Cognitive Neuroscience, Shanghai Key Laboratory of Magnetic Resonance Institute of Cognitive Neuroscience, East China Normal University, Shanghai, China
| | - Tianming Huang
- Department of General Psychiatry, Shanghai Changning Mental Health Center, Shanghai, China
| | - Chaozheng Tang
- Department of Rehabilitation Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Kaiji Ni
- Department of Psychiatry, HongKou District Mental Health Center of Shanghai, Shanghai, China
| | - Xiandi Pan
- Department of Psychiatry, Tongji Hospital of Tongji University, Shanghai, China
| | - Chao Yan
- Shanghai Key Laboratory of Brain Functional Genomics (MOE & STCSM), School of Psychology and Cognitive Science, East China Normal University, Shanghai, China
| | - Xiaoduo Fan
- Department of Psychiatry, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | - Dongrong Xu
- MRI Unit, New York State Psychiatric Institute and Columbia University, New York, NY, United States of America
| | - Yanli Luo
- Department of Psychological Medicine, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
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45
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Henderson LA, Keay KA. Imaging Acute and Chronic Pain in the Human Brainstem and Spinal Cord. Neuroscientist 2017; 24:84-96. [PMID: 28447501 DOI: 10.1177/1073858417703911] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
While acute pain serves as a protective mechanism designed to warn an individual of potential or actual damaging stimuli, chronic pain provides no benefit and is now considered a disease in its own right. Since the advent of human brain imaging techniques, many investigations that have explored the central representation of acute and chronic pain have focused on changes in higher order brain regions. In contrast, far fewer have explored brainstem and spinal cord function, mainly due to significant technical difficulties. In this review, we present some of the recent human brain imaging studies that have specifically explored brainstem and spinal cord function during acute noxious stimuli and in individuals with chronic pain. We focus particularly on investigations that explore changes in areas that receive nociceptor afferents and compare humans and experimental animal data in an attempt to describe both microscopic and macroscopic changes associated with acute and chronic pain.
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Affiliation(s)
- Luke A Henderson
- 1 Department of Anatomy and Histology, University of Sydney, Sydney, New South Wales, Australia
| | - Kevin A Keay
- 1 Department of Anatomy and Histology, University of Sydney, Sydney, New South Wales, Australia
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Brain activations during pain: a neuroimaging meta-analysis of patients with pain and healthy controls. Pain 2017; 157:1279-1286. [PMID: 26871535 DOI: 10.1097/j.pain.0000000000000517] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
In response to recent publications from pain neuroimaging experiments, there has been a debate about the existence of a primary pain region in the brain. Yet, there are few meta-analyses providing assessments of the minimum cerebral denominators of pain. Here, we used a statistical meta-analysis method, called activation likelihood estimation, to define (1) core brain regions activated by pain per se, irrelevant of pain modality, paradigm, or participants and (2) activation likelihood estimation commonalities and differences between patients with chronic pain and healthy individuals. A subtraction analysis of 138 independent data sets revealed that the minimum denominator for activation across pain modalities and paradigms included the right insula, secondary sensory cortex, and right anterior cingulate cortex (ACC). Common activations for healthy subjects and patients with pain alike included the thalamus, ACC, insula, and cerebellum. A comparative analysis revealed that healthy individuals were more likely to activate the cingulum, thalamus, and insula. Our results point toward the central role of the insular cortex and ACC in pain processing, irrelevant of modality, body part, or clinical experience; thus, furthering the importance of ACC and insular activation as key regions for the human experience of pain.
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47
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Silva AF, Zortea M, Carvalho S, Leite J, Torres ILDS, Fregni F, Caumo W. Anodal transcranial direct current stimulation over the left dorsolateral prefrontal cortex modulates attention and pain in fibromyalgia: randomized clinical trial. Sci Rep 2017; 7:135. [PMID: 28273933 PMCID: PMC5427889 DOI: 10.1038/s41598-017-00185-w] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 02/13/2017] [Indexed: 12/31/2022] Open
Abstract
Cognitive dysfunction in fibromyalgia patients has been reported, especially when increased attentional demands are required. Transcranial direct current stimulation (tDCS) over the dorsolateral prefrontal cortex (DLPFC) has been effective in modulating attention. We tested the effects of a single session of tDCS coupled with a Go/No-go task in modulating three distinct attentional networks: alertness, orienting and executive control. Secondarily, the effect on pain measures was evaluated. Forty females with fibromyalgia were randomized to receive active or sham tDCS. Anodal stimulation (1 mA, 20 min) was applied over the DLPFC. Attention indices were assessed using the Attention Network Test (ANT). Heat pain threshold (HPTh) and tolerance (HPTo) were measured. Active compared to sham tDCS led to increased performance in the orienting (mean difference [MD] = 14.63) and executive (MD = 21.00) attention networks. There was no effect on alertness. Active tDCS increased HPTh as compared to sham (MD = 1.93) and HPTo (MD = 1.52). Regression analysis showed the effect on executive attention is mostly independent of the effect on pain. DLPFC may be an important target for neurostimulation therapies in addition to the primary motor cortex for patients who do not respond adequately to neurostimulation therapies.
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Affiliation(s)
- Adriana Ferreira Silva
- Post Graduate Program in Medical Sciences, School of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Maxciel Zortea
- Post Graduate Program in Medical Sciences, School of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
- Laboratory of Pain & Neuromodulation, Clinical Hospital of Porto Alegre, Porto Alegre, Brazil
| | - Sandra Carvalho
- Spaulding Center of Neuromodulation, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts, USA
- Neuropsychophysiology Laboratory, CIPsi, School of Psychology (EPsi), University of Minho, Braga, Portugal
| | - Jorge Leite
- Spaulding Center of Neuromodulation, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts, USA
- Neuropsychophysiology Laboratory, CIPsi, School of Psychology (EPsi), University of Minho, Braga, Portugal
| | - Iraci Lucena da Silva Torres
- Post Graduate Program in Medical Sciences, School of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
- Pharmacology Department, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil
| | - Felipe Fregni
- Spaulding Center of Neuromodulation, Department of Physical Medicine and Rehabilitation, Harvard Medical School, Boston, Massachusetts, USA
| | - Wolnei Caumo
- Post Graduate Program in Medical Sciences, School of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
- Laboratory of Pain & Neuromodulation, Clinical Hospital of Porto Alegre, Porto Alegre, Brazil.
- Pharmacology Department, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
- Pain and Palliative Care Service, Clinical Hospital of Porto Alegre, Porto Alegre, Brazil.
- Surgery Department, School of Medicine, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
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48
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Masocha W. Gene expression profile of sodium channel subunits in the anterior cingulate cortex during experimental paclitaxel-induced neuropathic pain in mice. PeerJ 2016; 4:e2702. [PMID: 27896032 PMCID: PMC5119229 DOI: 10.7717/peerj.2702] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 10/19/2016] [Indexed: 12/19/2022] Open
Abstract
Paclitaxel, a chemotherapeutic agent, causes neuropathic pain whose supraspinal pathophysiology is not fully understood. Dysregulation of sodium channel expression, studied mainly in the periphery and spinal cord level, contributes to the pathogenesis of neuropathic pain. We examined gene expression of sodium channel (Nav) subunits by real time polymerase chain reaction (PCR) in the anterior cingulate cortex (ACC) at day 7 post first administration of paclitaxel, when mice had developed paclitaxel-induced thermal hyperalgesia. The ACC was chosen because increased activity in the ACC has been observed during neuropathic pain. In the ACC of vehicle-treated animals the threshold cycle (Ct) values for Nav1.4, Nav1.5, Nav1.7, Nav1.8 and Nav1.9 were above 30 and/or not detectable in some samples. Thus, comparison in mRNA expression between untreated control, vehicle-treated and paclitaxel treated animals was done for Nav1.1, Nav1.2, Nav1.3, Nav1.6, Nax as well as Navβ1–Navβ4. There were no differences in the transcript levels of Nav1.1–Nav1.3, Nav1.6, Nax, Navβ1–Navβ3 between untreated and vehicle-treated mice, however, vehicle treatment increased Navβ4 expression. Paclitaxel treatment significantly increased the mRNA expression of Nav1.1, Nav1.2, Nav1.6 and Nax, but not Nav1.3, sodium channel alpha subunits compared to vehicle-treated animals. Treatment with paclitaxel significantly increased the expression of Navβ1 and Navβ3, but not Navβ2 and Navβ4, sodium channel beta subunits compared to vehicle-treated animals. These findings suggest that during paclitaxel-induced neuropathic pain (PINP) there is differential upregulation of sodium channels in the ACC, which might contribute to the increased neuronal activity observed in the area during neuropathic pain.
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Affiliation(s)
- Willias Masocha
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University , Safat , Kuwait
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49
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Functional brain imaging: what has it brought to our understanding of neuropathic pain? A special focus on allodynic pain mechanisms. Pain 2016; 157 Suppl 1:S67-S71. [PMID: 26785157 DOI: 10.1097/j.pain.0000000000000387] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Brain responses to nociception are well identified. The same is not true for allodynic pain, a strong painful sensation in response to touch or innocuous cold stimuli that may be experienced by patients with neuropathic pain. Brain (or spinal cord) reorganization that may explain this paradoxical perception still remains largely unknown. Allodynic pain is associated with abnormally increased activity in SII and in the anterior insular cortex, contralateral and/or ipsilateral to allodynia. Because a bilateral increase in activity has been repeatedly reported in these areas in nociceptive conditions, the observed activation during allodynia can explain that a physiologically nonpainful stimulus could be perceived by the damaged nervous system as a painful one. Both secondary somatosensory and insular cortices receive input from the thalamus, which is a major relay of sensory and spinothalamic pathways, the involvement of which is known to be crucial for the development of neuropathic pain. Both thalamic function and structure have been reported to be abnormal or impaired in neuropathic pain conditions including in the basal state, possibly explaining the spontaneous component of neuropathic pain. A further indication as to how the brain can create neuropathic pain response in SII and insular cortices stems from examples of diseases, including single-case reports in whom a focal brain lesion leads to central pain disappearance. Additional studies are required to certify the contribution of these areas to the disease processes, to disentangle abnormalities respectively related to pain and to deafferentation, and, in the future, to guide targeting of stimulation studies.
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50
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Puentedura EJ, Flynn T. Combining manual therapy with pain neuroscience education in the treatment of chronic low back pain: A narrative review of the literature. Physiother Theory Pract 2016; 32:408-14. [PMID: 27362980 DOI: 10.1080/09593985.2016.1194663] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Teaching people with chronic low back pain (CLBP) about the neurobiology and neurophysiology of their pain is referred to as pain neuroscience education (PNE). There is growing evidence that when PNE is provided to patients with chronic musculoskeletal pain, it can result in decreased pain, pain catastrophization, disability, and improved physical performance. Because the aim of PNE is to shift the patient's focus from the tissues in the low back as the source of their pain to the brain's interpretation of inputs, many clinicians could mistakenly believe that PNE should be a "hands-off," education-only approach. An argument can be made that by providing manual therapy or exercise to address local tissue pathology, the patient's focus could be brought back to the low back tissues as the source of their problem. In this narrative literature review, we present the case for a balanced approach that combines PNE with manual therapy and exercise by considering how manual therapy can also be incorporated for interventions with patients with CLBP. We propose that as well as producing local mechanical effects, providing manual therapy within a PNE context can be seen as meeting or perhaps enhancing patient expectations, and also refreshing or sharpening body schema maps within the brain. Ideally, all of this should lead to better outcomes in patients with CLBP.
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Affiliation(s)
- Emilio J Puentedura
- a Department of Physical Therapy , University of Nevada, Las Vegas , Las Vegas , NV , USA
| | - Timothy Flynn
- b School of Physical Therapy , South College , Knoxville , TN , USA
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