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Jensen MP, Barrett TD. The Role of Electroencephalogram-Assessed Bandwidth Power in Response to Hypnotic Analgesia. Brain Sci 2024; 14:557. [PMID: 38928559 PMCID: PMC11201437 DOI: 10.3390/brainsci14060557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/28/2024] Open
Abstract
Research supports the efficacy of therapeutic hypnosis for reducing acute and chronic pain. However, little is known about the mechanisms underlying these effects. This paper provides a review of the evidence regarding the role that electroencephalogram-assessed bandwidth power has in identifying who might benefit the most from hypnotic analgesia and how these effects occur. Findings are discussed in terms of the slow wave hypothesis, which posits that brain activity in slower bandwidths (e.g., theta and alpha) can facilitate hypnosis responsivity. Although the extant research is limited by small sample sizes, the findings from this research are generally consistent with the slow wave hypothesis. More research, including and especially studies with larger sample sizes, is needed to confirm these preliminary positive findings.
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Affiliation(s)
- Mark P. Jensen
- Department of Rehabilitation Medicine, University of Washington, Seattle, WA 98195, USA;
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2
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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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3
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Rajan J, Gaur GS, Shanmugavel K, S A. Relation between heart rate variability and spectral analysis of electroencephalogram in chronic neuropathic pain patients. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2024; 28:253-264. [PMID: 38682173 PMCID: PMC11058544 DOI: 10.4196/kjpp.2024.28.3.253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 02/12/2024] [Accepted: 02/28/2024] [Indexed: 05/01/2024]
Abstract
Chronic neuropathic pain (CNP) is a complex condition often arising from neural maladaptation after nerve injury. Understanding CNP complications involves the intricate interplay between brain-heart dynamics, assessed through quantitative electroencephalogram (qEEG) and heart rate variability (HRV). However, insights into their interaction in chronic pain are limited. Resting EEG and simultaneous electrocardiogram (lead II) of the participants were recorded for qEEG and HRV analysis. Correlations between HRV and qEEG parameters were calculated and compared with age, sex, and body mass index (BMI)-matched controls. CNP patients showed reduced HRV and significant increases in qEEG power spectral densities within delta, theta, and beta frequency ranges. A positive correlation was found between low frequency/ high frequency (LF/HF) ratio in HRV analysis and theta, alpha, and beta frequency bands in qEEG among CNP patients. However, no significant correlation was observed between parasympathetic indices and theta, beta bands in qEEG within CNP group, unlike age, sex, and BMI-matched healthy controls. CNP patients display significant HRV reductions and distinctive qEEG patterns. While healthy controls exhibit significant correlations between parasympathetic HRV parameters and qEEG spectral densities, these relationships are diminished or absent in CNP individuals. LF/HF ratio, reflecting sympathovagal balance, correlates significantly with qEEG frequency bands (theta, alpha, beta), illuminating autonomic dysregulation in CNP. These findings emphasize the intricate brain-heart interplay in chronic pain, warranting further exploration.
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Affiliation(s)
- John Rajan
- Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry 605006, India
| | - Girwar Singh Gaur
- Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry 605006, India
| | - Karthik Shanmugavel
- Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry 605006, India
| | - Adinarayanan S
- Department of Anesthesiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Puducherry 605006, India
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Onofrj M, Russo M, Delli Pizzi S, De Gregorio D, Inserra A, Gobbi G, Sensi SL. The central role of the Thalamus in psychosis, lessons from neurodegenerative diseases and psychedelics. Transl Psychiatry 2023; 13:384. [PMID: 38092757 PMCID: PMC10719401 DOI: 10.1038/s41398-023-02691-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/06/2023] [Accepted: 11/27/2023] [Indexed: 12/17/2023] Open
Abstract
The PD-DLB psychosis complex found in Parkinson's disease (PD) and Dementia with Lewy Bodies (DLB) includes hallucinations, Somatic Symptom/Functional Disorders, and delusions. These disorders exhibit similar presentation patterns and progression. Mechanisms at the root of these symptoms also share similarities with processes promoting altered states of consciousness found in Rapid Eye Movement sleep, psychiatric disorders, or the intake of psychedelic compounds. We propose that these mechanisms find a crucial driver and trigger in the dysregulated activity of high-order thalamic nuclei set in motion by ThalamoCortical Dysrhythmia (TCD). TCD generates the loss of finely tuned cortico-cortical modulations promoted by the thalamus and unleashes the aberrant activity of the Default Mode Network (DMN). TCD moves in parallel with altered thalamic filtering of external and internal information. The process produces an input overload to the cortex, thereby exacerbating DMN decoupling from task-positive networks. These phenomena alter the brain metastability, creating dreamlike, dissociative, or altered states of consciousness. In support of this hypothesis, mind-altering psychedelic drugs also modulate thalamic-cortical pathways. Understanding the pathophysiological background of these conditions provides a conceptual bridge between neurology and psychiatry, thereby helping to generate a promising and converging area of investigation and therapeutic efforts.
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Affiliation(s)
- Marco Onofrj
- Behavioral Neurology and Molecular Neurology Units, Center for Advanced Studies and Technology - CAST, Institute for Advanced Biomedical Technology-ITAB University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
| | - Mirella Russo
- Behavioral Neurology and Molecular Neurology Units, Center for Advanced Studies and Technology - CAST, Institute for Advanced Biomedical Technology-ITAB University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Stefano Delli Pizzi
- Behavioral Neurology and Molecular Neurology Units, Center for Advanced Studies and Technology - CAST, Institute for Advanced Biomedical Technology-ITAB University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Danilo De Gregorio
- Division of Neuroscience, Vita-Salute San Raffaele University, Milan, Italy
| | - Antonio Inserra
- Neurobiological Psychiatry Unit, McGill University, Montreal, QC, Canada
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, McGill University, Montreal, QC, Canada
| | - Stefano L Sensi
- Behavioral Neurology and Molecular Neurology Units, Center for Advanced Studies and Technology - CAST, Institute for Advanced Biomedical Technology-ITAB University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
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Lopes TS, Santana JE, Silva WS, Fraga FJ, Montoya P, Sá KN, Lopes LC, Lucena R, Zana Y, Baptista AF. Increased Delta and Theta Power Density in Sickle Cell Disease Individuals with Chronic Pain Secondary to Hip Osteonecrosis: A Resting-State Eeg Study. Brain Topogr 2023:10.1007/s10548-023-01027-x. [PMID: 38060074 DOI: 10.1007/s10548-023-01027-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 11/27/2023] [Indexed: 12/08/2023]
Abstract
PURPOSE Identify the presence of a dysfunctional electroencephalographic (EEG) pattern in individuals with sickle cell disease (SCD) and hip osteonecrosis, and assess its potential associations with depression, anxiety, pain severity, and serum levels of brain-derived neurotrophic factor (BDNF). METHODS In this cross-sectional investigation, 24 SCD patients with hip osteonecrosis and chronic pain were matched by age and sex with 19 healthy controls. Resting-state EEG data were recorded using 32 electrodes for both groups. Power spectral density (PSD) and peak alpha frequency (PAF) were computed for each electrode across Delta, Theta, Alpha, and Beta frequency bands. Current Source Density (CSD) measures were performed utilizing the built-in Statistical nonparametric Mapping Method of the LORETA-KEY software. RESULTS Our findings demonstrated that SCD individuals exhibited higher PSD in delta and theta frequency bands when compared to healthy controls. Moreover, SCD individuals displayed increased CSD in delta and theta frequencies, coupled with decreased CSD in the alpha frequency within brain regions linked to pain processing, motor function, emotion, and attention. In comparison to the control group, depression symptoms, and pain intensity during hip abduction were positively correlated with PSD and CSD in the delta frequency within the parietal region. Depression symptoms also exhibited a positive association with PSD and CSD in the theta frequency within the same region, while serum BDNF levels showed a negative correlation with CSD in the alpha frequency within the left insula. CONCLUSION This study indicates that individuals with SCD experiencing hip osteonecrosis and chronic pain manifest a dysfunctional EEG pattern characterized by the persistence of low-frequency PSD during a resting state. This dysfunctional EEG pattern may be linked to clinical and biochemical outcomes, including depression symptoms, pain severity during movement, and serum BDNF levels.
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Affiliation(s)
- Tiago S Lopes
- Center for Mathematics, Computation, and Cognition, Federal University of ABC, Santo Andre, Brazil.
- NAPEN network (Nucleus of Assistance, Research, and Teaching in Neuromodulation), São Paulo, Brazil.
- Bahia Adventist College, Cachoeira, Brazil.
| | - Jamille E Santana
- Center for Mathematics, Computation, and Cognition, Federal University of ABC, Santo Andre, Brazil
- NAPEN network (Nucleus of Assistance, Research, and Teaching in Neuromodulation), São Paulo, Brazil
| | | | - Francisco J Fraga
- Engineering, Modelling, and Applied Social Sciences Center, Federal University of ABC, Santo André, SP, Brazil
| | - Pedro Montoya
- Center for Mathematics, Computation, and Cognition, Federal University of ABC, Santo Andre, Brazil
- Research Institute of Health Sciences, University of Balearic Islands, Palma de Mallorca, Spain
| | - Katia N Sá
- NAPEN network (Nucleus of Assistance, Research, and Teaching in Neuromodulation), São Paulo, Brazil
- Postgraduate and Research, Escola Bahiana de Medicina e Saúde Pública, Salvador, Bahia, Brazil
| | - Larissa C Lopes
- Graduate Program in Medicine and Health, Federal University of Bahia, Salvador, Brazil
| | - Rita Lucena
- Graduate Program in Medicine and Health, Federal University of Bahia, Salvador, Brazil
| | - Yossi Zana
- Center for Mathematics, Computation, and Cognition, Federal University of ABC, Santo Andre, Brazil
| | - Abrahão F Baptista
- Center for Mathematics, Computation, and Cognition, Federal University of ABC, Santo Andre, Brazil
- NAPEN network (Nucleus of Assistance, Research, and Teaching in Neuromodulation), São Paulo, Brazil
- Laboratory of Medical Investigations 54, Clinics Hospital, São Paulo State University, São Paulo, Brazil
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Rockholt MM, Kenefati G, Doan LV, Chen ZS, Wang J. In search of a composite biomarker for chronic pain by way of EEG and machine learning: where do we currently stand? Front Neurosci 2023; 17:1186418. [PMID: 37389362 PMCID: PMC10301750 DOI: 10.3389/fnins.2023.1186418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/12/2023] [Indexed: 07/01/2023] Open
Abstract
Machine learning is becoming an increasingly common component of routine data analyses in clinical research. The past decade in pain research has witnessed great advances in human neuroimaging and machine learning. With each finding, the pain research community takes one step closer to uncovering fundamental mechanisms underlying chronic pain and at the same time proposing neurophysiological biomarkers. However, it remains challenging to fully understand chronic pain due to its multidimensional representations within the brain. By utilizing cost-effective and non-invasive imaging techniques such as electroencephalography (EEG) and analyzing the resulting data with advanced analytic methods, we have the opportunity to better understand and identify specific neural mechanisms associated with the processing and perception of chronic pain. This narrative literature review summarizes studies from the last decade describing the utility of EEG as a potential biomarker for chronic pain by synergizing clinical and computational perspectives.
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Affiliation(s)
- Mika M. Rockholt
- Department of Anesthesiology, Perioperative Care and Pain Management, New York University Grossman School of Medicine, New York, NY, United States
| | - George Kenefati
- Department of Anesthesiology, Perioperative Care and Pain Management, New York University Grossman School of Medicine, New York, NY, United States
| | - Lisa V. Doan
- Department of Anesthesiology, Perioperative Care and Pain Management, New York University Grossman School of Medicine, New York, NY, United States
| | - Zhe Sage Chen
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
- Department of Neuroscience & Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biomedical Engineering, New York University Tandon School of Engineering, Brooklyn, NY, United States
| | - Jing Wang
- Department of Anesthesiology, Perioperative Care and Pain Management, New York University Grossman School of Medicine, New York, NY, United States
- Department of Neuroscience & Physiology, Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, United States
- Department of Biomedical Engineering, New York University Tandon School of Engineering, Brooklyn, NY, United States
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7
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Zebhauser PT, Hohn VD, Ploner M. Resting-state electroencephalography and magnetoencephalography as biomarkers of chronic pain: a systematic review. Pain 2023; 164:1200-1221. [PMID: 36409624 PMCID: PMC10184564 DOI: 10.1097/j.pain.0000000000002825] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 10/28/2022] [Accepted: 11/04/2022] [Indexed: 11/22/2022]
Abstract
ABSTRACT Reliable and objective biomarkers promise to improve the assessment and treatment of chronic pain. Resting-state electroencephalography (EEG) is broadly available, easy to use, and cost efficient and, therefore, appealing as a potential biomarker of chronic pain. However, results of EEG studies are heterogeneous. Therefore, we conducted a systematic review (PROSPERO CRD42021272622) of quantitative resting-state EEG and magnetoencephalography (MEG) studies in adult patients with different types of chronic pain. We excluded populations with severe psychiatric or neurologic comorbidity. Risk of bias was assessed using a modified Newcastle-Ottawa Scale. Semiquantitative data synthesis was conducted using modified albatross plots. We included 76 studies after searching MEDLINE, Web of Science Core Collection, Cochrane Central Register of Controlled Trials, and EMBASE. For cross-sectional studies that can serve to develop diagnostic biomarkers, we found higher theta and beta power in patients with chronic pain than in healthy participants. For longitudinal studies, which can yield monitoring and/or predictive biomarkers, we found no clear associations of pain relief with M/EEG measures. Similarly, descriptive studies that can yield diagnostic or monitoring biomarkers showed no clear correlations of pain intensity with M/EEG measures. Risk of bias was high in many studies and domains. Together, this systematic review synthesizes evidence on how resting-state M/EEG might serve as a diagnostic biomarker of chronic pain. Beyond, this review might help to guide future M/EEG studies on the development of pain biomarkers.
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Affiliation(s)
- Paul Theo Zebhauser
- Department of Neurology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
| | - Vanessa D. Hohn
- Department of Neurology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
| | - Markus Ploner
- Department of Neurology, School of Medicine, Technical University of Munich (TUM), Munich, Germany
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8
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Ming LG, Hu DX, Zuo C, Zhang WJ. G protein-coupled P2Y12 receptor is involved in the progression of neuropathic pain. Biomed Pharmacother 2023; 162:114713. [PMID: 37084563 DOI: 10.1016/j.biopha.2023.114713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Revised: 04/13/2023] [Accepted: 04/14/2023] [Indexed: 04/23/2023] Open
Abstract
The pathological mechanism of neuropathic pain is complex, which seriously affects the physical and mental health of patients, and its treatment is also difficult. The role of G protein-coupled P2Y12 receptor in pain has been widely recognized and affirmed. After nerve injury, stimulated cells can release large amounts of nucleotides into the extracellular matrix, act on P2Y12 receptor. Activated P2Y12 receptor activates intracellular signal transduction and is involved in the development of pain. P2Y12 receptor activation can sensitize primary sensory neurons and receive sensory information. By transmitting the integrated information through the dorsal root of the spinal cord to the secondary neurons of the posterior horn of the spinal cord. The integrated information is then transmitted to the higher center through the ascending conduction tract to produce pain. Moreover, activation of P2Y12 receptor can mediate immune cells to release pro-inflammatory factors, increase damage to nerve cells, and aggravate pain. While inhibits the activation of P2Y12 receptor can effectively relieve pain. Therefore, in this article, we described P2Y12 receptor antagonists and their pharmacological properties. In addition, we explored the potential link between P2Y12 receptor and the nervous system, discussed the intrinsic link of P2Y12 receptor and neuropathic pain and as a potential pharmacological target for pain suppression.
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Affiliation(s)
- Li-Guo Ming
- Department of Gastrointestinal surgery, the Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi Province 343000, China
| | - Dong-Xia Hu
- Department of Rehabilitation Medicine, the Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi Province 343000, China
| | - Cheng Zuo
- Department of Gastrointestinal surgery, the Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi Province 343000, China
| | - Wen-Jun Zhang
- Department of Rehabilitation Medicine, the Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi Province 343000, China.
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9
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Liu J, Chen DH, Li XS, Xu CY, Hu T. Activating PV-positive neurons in ventral thalamic reticular nucleus reduces pain sensitivity in mice. Brain Res 2023; 1799:148174. [PMID: 36427592 DOI: 10.1016/j.brainres.2022.148174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/01/2022] [Accepted: 11/20/2022] [Indexed: 11/25/2022]
Abstract
Previous studies have demonstrated that thalamic reticular nucleus (TRN) and the sub-nuclei play important roles in pain sensation. Our previous findings showed that activating parvalbumin-positive (PV+) neurons in dorsal sector of TRN (dTRN) could reduce the pain threshold and consequently increase the pain sensitivity of mice. Recent studies have shown that activation of GABAergic projection of TRN to ventrobasal thalamus (VB) alleviated pathological pain. GABAergic neurons in TRN are mainly PV+ neurons. However, the exact roles of ventral TRN (vTRN) PV+ neurons in pain sensation remain unclear. In this study, the designer receptors exclusively activated by designer drugs (DREADD) method was used to activate the PV+ neurons in vTRN of PV-Cre transgenic mice, and the mechanical threshold and thermal latency were measured to investigate the regulatory effects of vTRN on pain sensitivity in mice. Thereafter, PV-Cre transgenic mice, conditional anterograde axonal tract tracing, and immunohistochemistry were used to investigate the distribution of PV+ neurons fibers in vTRN. The results showed that the activation of PV+ neurons in vTRN increased the mechanical threshold and thermal latency, which indicated reduction of pain sensitivity. The fibers of these neurons mainly projected to ventral posterolateral thalamic nucleus (VPL), ventral posteromedial thalamic nucleus (VPM), ventrolateral thalamic nucleus (VL), centrolateral thalamic nucleus (CL) and various other brain regions. These findings indicated that activation of PV+ neurons in the vTRN decreased pain sensitivity in mice, which provided additional evidence on the mechanisms of PV+ neurons of TRN in regulating neuralgia.
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Affiliation(s)
- Jing Liu
- Department of Cell Biology and Neurobiology, Life Sciences College, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China; Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Dan-Hua Chen
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Xiao-Shuang Li
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Chuan-Ying Xu
- Department of Neurology, The Affiliated Hospital of Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China.
| | - Tao Hu
- Department of Anatomy, Basic Medical College, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China.
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10
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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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11
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Fauchon C, Kim JA, El-Sayed R, Osborne NR, Rogachov A, Cheng JC, Hemington KS, Bosma RL, Dunkley BT, Oh J, Bhatia A, Inman RD, Davis KD. A Hidden Markov Model reveals magnetoencephalography spectral frequency-specific abnormalities of brain state power and phase-coupling in neuropathic pain. Commun Biol 2022; 5:1000. [PMID: 36131088 PMCID: PMC9492713 DOI: 10.1038/s42003-022-03967-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 09/08/2022] [Indexed: 11/09/2022] Open
Abstract
Neuronal populations in the brain are engaged in a temporally coordinated manner at rest. Here we show that spontaneous transitions between large-scale resting-state networks are altered in chronic neuropathic pain. We applied an approach based on the Hidden Markov Model to magnetoencephalography data to describe how the brain moves from one activity state to another. This identified 12 fast transient (~80 ms) brain states including the sensorimotor, ascending nociceptive pathway, salience, visual, and default mode networks. Compared to healthy controls, we found that people with neuropathic pain exhibited abnormal alpha power in the right ascending nociceptive pathway state, but higher power and coherence in the sensorimotor network state in the beta band, and shorter time intervals between visits of the sensorimotor network, indicating more active time in this state. Conversely, the neuropathic pain group showed lower coherence and spent less time in the frontal attentional state. Therefore, this study reveals a temporal imbalance and dysregulation of spectral frequency-specific brain microstates in patients with neuropathic pain. These findings can potentially impact the development of a mechanism-based therapeutic approach by identifying brain targets to stimulate using neuromodulation to modify abnormal activity and to restore effective neuronal synchrony between brain states.
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Affiliation(s)
- Camille Fauchon
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada
| | - Junseok A Kim
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Rima El-Sayed
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Natalie R Osborne
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Anton Rogachov
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Joshua C Cheng
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Kasey S Hemington
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Rachael L Bosma
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada
| | - Benjamin T Dunkley
- Neurosciences & Mental Health Program, The Hospital for Sick Children Research Institute, Toronto, ON, M5G 0A4, Canada.,Diagnostic Imaging, The Hospital for Sick Children, Toronto, ON, M5G 0A4, Canada.,Department of Medical Imaging, University of Toronto, Toronto, ON, M5T 1W7, Canada
| | - Jiwon Oh
- Div of Neurology, Dept of Medicine, St. Michael's Hospital, Toronto, ON, M5B 1W8, Canada
| | - Anuj Bhatia
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada.,Department of Anesthesia and Pain Medicine, Toronto Western Hospital, and University of Toronto, Toronto, ON, M5T 2S8, Canada
| | - Robert D Inman
- Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada.,Division of Immunology, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Karen Deborah Davis
- Division of Brain, Imaging, and Behaviour, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 2S8, Canada. .,Institute of Medical Science, University of Toronto, Toronto, ON, M5S 1A8, Canada. .,Department of Surgery, University of Toronto, Toronto, ON, M5T 1P5, Canada.
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12
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Exploring sex differences in alpha brain activity as a potential neuromarker associated with neuropathic pain. Pain 2022; 163:1291-1302. [PMID: 34711764 DOI: 10.1097/j.pain.0000000000002491] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 09/09/2021] [Indexed: 12/31/2022]
Abstract
ABSTRACT Alpha oscillatory activity (8-13 Hz) is the dominant rhythm in the awake brain and is known to play an important role in pain states. Previous studies have identified alpha band slowing and increased power in the dynamic pain connectome (DPC) of people with chronic neuropathic pain. However, a link between alpha-band abnormalities and sex differences in brain organization in healthy individuals and those with chronic pain is not known. Here, we used resting-state magnetoencephalography to test the hypothesis that peak alpha frequency (PAF) abnormalities are general features across chronic central and peripheral conditions causing neuropathic pain but exhibit sex-specific differences in networks of the DPC (ascending nociceptive pathway [ANP], default mode network, salience network [SN], and subgenual anterior cingulate cortex). We found that neuropathic pain (N = 25 men and 25 women) was associated with increased PAF power in the DPC compared with 50 age- and sex-matched healthy controls, whereas slower PAF in nodes of the SN (temporoparietal junction) and the ANP (posterior insula) was associated with higher trait pain intensity. In the neuropathic pain group, women exhibited lower PAF power in the subgenual anterior cingulate cortex and faster PAF in the ANP and SN than men. The within-sex analyses indicated that women had neuropathic pain-related increased PAF power in the ANP, SN, and default mode network, whereas men with neuropathic pain had increased PAF power restricted to the ANP. These findings highlight neuropathic pain-related and sex-specific abnormalities in alpha oscillations across the DPC that could underlie aberrant neuronal communication in nociceptive processing and modulation.
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13
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Mussigmann T, Bardel B, Lefaucheur JP. Resting-state electroencephalography (EEG) biomarkers of chronic neuropathic pain. A systematic review. Neuroimage 2022; 258:119351. [PMID: 35659993 DOI: 10.1016/j.neuroimage.2022.119351] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/09/2022] [Accepted: 05/31/2022] [Indexed: 10/18/2022] Open
Abstract
Diagnosis and management of chronic neuropathic pain are challenging, leading to current efforts to characterize 'objective' biomarkers of pain using imaging or neurophysiological techniques, such as electroencephalography (EEG). A systematic literature review was conducted in PubMed-Medline and Web-of-Science until October 2021 to identify EEG biomarkers of chronic neuropathic pain in humans. The risk of bias was assessed by the Newcastle-Ottawa-Scale. Experimental, provoked, or chronic non-neuropathic pain studies were excluded. We identified 14 studies, in which resting-state EEG spectral analysis was compared between patients with pain related to a neurological disease and patients with the same disease but without pain or healthy controls. From these heterogeneous exploratory studies, some conclusions can be drawn, even if they must be weighted by the fact that confounding factors, such as medication and association with anxio-depressive disorders, are generally not taken into account. Overall, EEG signal power was increased in the θ band (4-7Hz) and possibly in the high-β band (20-30Hz), but decreased in the high-α-low-β band (10-20Hz) in the presence of ongoing neuropathic pain, while increased γ band oscillations were not evidenced, unlike in experimental pain. Consequently, the dominant peak frequency was decreased in the θ-α band and increased in the whole-β band in neuropathic pain patients. Disappointingly, pain intensity correlated with various EEG changes across studies, with no consistent trend. This review also discusses the location of regional pain-related EEG changes in the pain connectome, as the perspectives offered by advanced techniques of EEG signal analysis (source location, connectivity, or classification methods based on artificial intelligence). The biomarkers provided by resting-state EEG are of particular interest for optimizing the treatment of chronic neuropathic pain by neuromodulation techniques, such as transcranial alternating current stimulation or neurofeedback procedures.
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Affiliation(s)
- Thibaut Mussigmann
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France
| | - Benjamin Bardel
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France
| | - Jean-Pascal Lefaucheur
- Univ Paris Est Creteil, EA4391, ENT, Créteil, France; Clinical Neurophysiology Unit, Henri Mondor Hospital, AP-HP, Créteil, France.
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14
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Effect of surgical damage to spinal nerve on dorsal root ganglion genes expression: Comprehensive analysis of differentially expressed genes. Asian J Surg 2022; 45:2618-2625. [PMID: 35184964 DOI: 10.1016/j.asjsur.2021.12.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Revised: 12/01/2021] [Accepted: 12/17/2021] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Neuropathic pain can cause significant physical and economic burden, and there are no effective long-term treatments. We conducted a bioinformatics analysis to identify mechanisms to determine strategies for more effective treatments of neuropathic pain. METHOD GSE24982 and GSE63442 microarray datasets were extracted from the Gene Expression Omnibus database to analyze transcriptome differences of neuropathic pain in the dorsal root ganglions (DRGs). We filtered the differentially expressed genes (DEGs) in the two datasets and conducted Gene Ontology (GO) functional analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the shared DEGs. The Protein-Protein Interaction network was used to determine the hub genes, which were verified in the GSE30691 dataset. miRDB and miRWalk Databases were used to predict potential miRNA of the selected DEGs. We made the spinal nerve ligation (SNL) rat model and qPCR was used to verify the differential expression of hub genes. RESULTS A total of 182 overlapped DEGs were found between GSE24982 and GSE63442 datasets. The GO and KEGG analysis showed that the selected DEGs were enriched in infection, transmembrane transport of ion channels, and synaptic transmission. We identified seven hub genes (Atf3, Aif1, Ctss, Gfap, Scg2, Jun, and Vgf). qPCR verified the expression differences of the hub genes in the DRGs after SNL model. Predicted miRNA targeting each selected hub genes were identified. CONCLUSIONS Seven hub genes related to the pathogenesis of neuropathic pain and potential targeting miRNA were identified, expanding understanding of the mechanism of neuropathic pain and facilitating treatment development.
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15
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Zhang P, Jiang Y, Liu G, Han J, Wang J, Ma L, Hu W, Zhang J. Altered brain functional network dynamics in classic trigeminal neuralgia: a resting-state functional magnetic resonance imaging study. J Headache Pain 2021; 22:147. [PMID: 34895135 PMCID: PMC8903588 DOI: 10.1186/s10194-021-01354-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 11/06/2021] [Indexed: 12/20/2022] Open
Abstract
Background Accumulating studies have indicated a wide range of brain alterations with respect to the structure and function of classic trigeminal neuralgia (CTN). Given the dynamic nature of pain experience, the exploration of temporal fluctuations in interregional activity covariance may enhance the understanding of pain processes in the brain. The present study aimed to characterize the temporal features of functional connectivity (FC) states as well as topological alteration in CTN. Methods Resting-state functional magnetic resonance imaging and three-dimensional T1-weighted images were obtained from 41 CTN patients and 43 matched healthy controls (HCs). After group independent component analysis, sliding window based dynamic functional network connectivity (dFNC) analysis was applied to investigate specific FC states and related temporal properties. Then, the dynamics of the whole brain topological organization were estimated by calculating the coefficient of variation of graph-theoretical properties. Further correlation analyses were performed between all these measurements and clinical data. Results Two distinct states were identified. Of these, the state 2, characterized by complicated coupling between default mode network (DMN) and cognitive control network (CC) and tight connections within DMN, was expressed more in CTN patients and presented as increased fractional windows and dwell time. Moreover, patients switched less frequently between states than HCs. Regarding the dynamic topological analysis, disruptions in global graph-theoretical properties (including network efficiency and small-worldness) were observed in patients, coupled with decreased variability in nodal efficiency of anterior cingulate cortex (ACC) in the salience network (SN) and the thalamus and caudate nucleus in the subcortical network (SC). The variation of topological properties showed negative correlation with disease duration and attack frequency. Conclusions The present study indicated disrupted flexibility of brain topological organization under persistent noxious stimulation and further highlighted the important role of “dynamic pain connectome” regions (including DMN/CC/SN) in the pathophysiology of CTN from the temporal fluctuation aspect. Additionally, the findings provided supplementary evidence for current knowledge about the aberrant cortical-subcortical interaction in pain development. Supplementary Information The online version contains supplementary material available at 10.1186/s10194-021-01354-z.
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Affiliation(s)
- Pengfei Zhang
- Second Clinical School, Lanzhou University, Lanzhou, 730000, China.,Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, 730000, China
| | - Yanli Jiang
- Second Clinical School, Lanzhou University, Lanzhou, 730000, China.,Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, 730000, China
| | - Guangyao Liu
- Second Clinical School, Lanzhou University, Lanzhou, 730000, China.,Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, 730000, China
| | - Jiao Han
- Second Clinical School, Lanzhou University, Lanzhou, 730000, China
| | - Jun Wang
- Second Clinical School, Lanzhou University, Lanzhou, 730000, China.,Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, 730000, China
| | - Laiyang Ma
- Second Clinical School, Lanzhou University, Lanzhou, 730000, China.,Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, 730000, China
| | - Wanjun Hu
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, 730000, China
| | - Jing Zhang
- Department of Magnetic Resonance, Lanzhou University Second Hospital, Lanzhou, 730000, China. .,Gansu Province Clinical Research Center for Functional and Molecular Imaging, Cuiyingmen No.82, Chengguan District, Lanzhou, 730030, P. R. China.
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16
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De Ridder D, Adhia D, Vanneste S. The anatomy of pain and suffering in the brain and its clinical implications. Neurosci Biobehav Rev 2021; 130:125-146. [PMID: 34411559 DOI: 10.1016/j.neubiorev.2021.08.013] [Citation(s) in RCA: 60] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 08/09/2021] [Accepted: 08/13/2021] [Indexed: 02/08/2023]
Abstract
Pain is an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Chronic pain, with a prevalence of 20-30 % is the major cause of human suffering worldwide, because effective, specific and safe therapies have yet to be developed. It is unevenly distributed among sexes, with women experiencing more pain and suffering. Chronic pain can be anatomically and phenomenologically dissected into three separable but interacting pathways, a lateral 'painfulness' pathway, a medial 'suffering' pathway and a descending pain inhibitory pathway. One may have pain(fullness) without suffering and suffering without pain(fullness). Pain sensation leads to suffering via a cognitive, emotional and autonomic processing, and is expressed as anger, fear, frustration, anxiety and depression. The medial pathway overlaps with the salience and stress networks, explaining that behavioural relevance or meaning determines the suffering associated with painfulness. Genetic and epigenetic influences trigger chronic neuroinflammatory changes which are involved in transitioning from acute to chronic pain. Based on the concept of the Bayesian brain, pain (and suffering) can be regarded as the consequence of an imbalance between the two ascending and the descending pain inhibitory pathways under control of the reward system. The therapeutic clinical implications of this simple pain model are obvious. After categorizing the working mechanisms of each of the available treatments (pain killers, psychopharmacology, psychotherapy, neuromodulation, psychosurgery, spinal cord stimulation) to 1 or more of the 3 pathways, a rational combination can be proposed of activating the descending pain inhibitory pathway in combination with inhibition of the medial and lateral pathway, so as to rebalance the pain (and suffering) pathways.
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Affiliation(s)
- Dirk De Ridder
- Section of Neurosurgery, Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand.
| | - Divya Adhia
- Section of Neurosurgery, Department of Surgical Sciences, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
| | - Sven Vanneste
- Global Brain Health Institute, Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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17
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Peek AL, Leaver AM, Foster S, Oeltzschner G, Puts NA, Galloway G, Sterling M, Ng K, Refshauge K, Aguila MER, Rebbeck T. Increased GABA+ in People With Migraine, Headache, and Pain Conditions- A Potential Marker of Pain. THE JOURNAL OF PAIN 2021; 22:1631-1645. [PMID: 34182103 DOI: 10.1016/j.jpain.2021.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 05/25/2021] [Accepted: 06/04/2021] [Indexed: 11/27/2022]
Abstract
Treatment outcomes for migraine and other chronic headache and pain conditions typically demonstrate modest results. A greater understanding of underlying pain mechanisms may better inform treatments and improve outcomes. Increased GABA+ has been identified in recent studies of migraine, however, it is unclear if this is present in other headache, and pain conditions. We primarily investigated GABA+ levels in the posterior cingulate gyrus (PCG) of people with migraine, whiplash-headache and low back pain compared to age- and sex-matched controls, GABA+ levels in the anterior cingulate cortex (ACC) and thalamus formed secondary aims. Using a cross-sectional design, we studied people with migraine, whiplash-headache or low back pain (n = 56) and compared them with a pool of age- and sex-matched controls (n = 22). We used spectral-edited magnetic resonance spectroscopy at 3T (MEGA-PRESS) to determine levels of GABA+ in the PCG, ACC and thalamus. PCG GABA+ levels were significantly higher in people with migraine and low back pain compared with controls (eg, migraine 4.89 IU ± 0.62 vs controls 4.62 IU ± 0.38; P = .02). Higher GABA+ levels in the PCG were not unique to migraine and could reflect a mechanism of chronic pain in general. A better understanding of pain at a neurochemical level informs the development of treatments that target aberrant brain neurochemistry to improve patient outcomes. PERSPECTIVE: This study provides insights into the underlying mechanisms of chronic pain. Higher levels of GABA+ in the PCG may reflect an underlying mechanism of chronic headache and pain conditions. This knowledge may help improve patient outcomes through developing treatments that specifically address this aberrant brain neurochemistry.
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Affiliation(s)
- Aimie L Peek
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia; NHMRC Centre of Research Excellence in Road Traffic Injury Recovery, Queensland, Australia.
| | - Andrew M Leaver
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | - Sheryl Foster
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia; Department of Radiology, Westmead Hospital, New South Wales, Australia
| | - Georg Oeltzschner
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland; F.M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Institute, Baltimore, Maryland
| | - Nicolaas A Puts
- Department of Forensic and Neurodevelopmental Sciences, Sackler Institute for Translational Neurodevelopment, Institute of Psychiatry, Psychology, and Neuroscience, King's College London, UK; MRC Centre for Neurodevelopmental Disorders, King's College London, UK
| | - Graham Galloway
- The University of Queensland, Brisbane, Queensland, Australia; Translational Research Institute, Woolloongabba, Queensland, Australia
| | - Michele Sterling
- NHMRC Centre of Research Excellence in Road Traffic Injury Recovery, Queensland, Australia; RECOVER Injury Research Centre, Herston, Queensland, Australia
| | - Karl Ng
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia; Department of Neurology, Royal North Shore Hospital, New South Wales, Australia
| | - Kathryn Refshauge
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia
| | | | - Trudy Rebbeck
- Faculty of Medicine and Health, University of Sydney, Sydney, Australia; NHMRC Centre of Research Excellence in Road Traffic Injury Recovery, Queensland, Australia
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18
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Ma RE, Murdoch JB, Bogner W, Andronesi O, Dydak U. Atlas-based GABA mapping with 3D MEGA-MRSI: Cross-correlation to single-voxel MRS. NMR IN BIOMEDICINE 2021; 34:e4275. [PMID: 32078755 PMCID: PMC7438238 DOI: 10.1002/nbm.4275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Revised: 01/11/2020] [Accepted: 01/23/2020] [Indexed: 06/10/2023]
Abstract
The purpose of this work is to develop and validate a new atlas-based metabolite quantification pipeline for edited magnetic resonance spectroscopic imaging (MEGA-MRSI) that enables group comparisons of brain structure-specific GABA levels. By using brain structure masks segmented from high-resolution MPRAGE images and coregistering these to MEGA-LASER 3D MRSI data, an automated regional quantification of neurochemical levels is demonstrated for the example of the thalamus. Thalamic gamma-aminobutyric acid + coedited macromolecules (GABA+) levels from 21 healthy subjects scanned at 3 T were cross-validated both against a single-voxel MEGA-PRESS acquisition in the same subjects and same scan sessions, as well as alternative MRSI processing techniques (ROI approach, four-voxel approach) using Pearson correlation analysis. In addition, reproducibility was compared across the MRSI processing techniques in test-retest data from 14 subjects. The atlas-based approach showed a significant correlation with SV MEGA-PRESS (correlation coefficient r [GABA+] = 0.63, P < 0.0001). However, the actual values for GABA+, NAA, tCr, GABA+/tCr and tNAA/tCr obtained from the atlas-based approach showed an offset to SV MEGA-PRESS levels, likely due to the fact that on average the thalamus mask used for the atlas-based approach only occupied 30% of the SVS volume, ie, somewhat different anatomies were sampled. Furthermore, the new atlas-based approach showed highly reproducible GABA+/tCr values with a low median coefficient of variance of 6.3%. In conclusion, the atlas-based metabolite quantification approach enables a more brain structure-specific comparison of GABA+ and other neurochemical levels across populations, even when using an MRSI technique with only cm-level resolution. This approach was successfully cross-validated against the typically used SVS technique as well as other different MRSI analysis methods, indicating the robustness of this quantification approach.
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Affiliation(s)
- Ruoyun E. Ma
- Center for Magnetic Resonance Research, Department of Radiology, University of Minnesota, Minneapolis, MN, USA
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | - Wolfgang Bogner
- High Field MR Center, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Ovidiu Andronesi
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ulrike Dydak
- School of Health Sciences, Purdue University, West Lafayette, IN, USA
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
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19
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Martinelli D, Castellazzi G, De Icco R, Bacila A, Allena M, Faggioli A, Sances G, Pichiecchio A, Borsook D, Gandini Wheeler-Kingshott CAM, Tassorelli C. Thalamocortical Connectivity in Experimentally-Induced Migraine Attacks: A Pilot Study. Brain Sci 2021; 11:165. [PMID: 33514029 PMCID: PMC7911420 DOI: 10.3390/brainsci11020165] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/19/2021] [Accepted: 01/20/2021] [Indexed: 11/17/2022] Open
Abstract
In this study we used nitroglycerin (NTG)-induced migraine attacks as a translational human disease model. Static and dynamic functional connectivity (FC) analyses were applied to study the associated functional brain changes. A spontaneous migraine-like attack was induced in five episodic migraine (EM) patients using a NTG challenge. Four task-free functional magnetic resonance imaging (fMRI) scans were acquired over the study: baseline, prodromal, full-blown, and recovery. Seed-based correlation analysis (SCA) was applied to fMRI data to assess static FC changes between the thalamus and the rest of the brain. Wavelet coherence analysis (WCA) was applied to test time-varying phase-coherence changes between the thalamus and salience networks (SNs). SCA results showed significantly FC changes between the right thalamus and areas involved in the pain circuits (insula, pons, cerebellum) during the prodromal phase, reaching its maximal alteration during the full-blown phase. WCA showed instead a loss of synchronisation between thalami and SN, mainly occurring during the prodrome and full-blown phases. These findings further support the idea that a temporal change in thalamic function occurs over the experimentally induced phases of NTG-induced headache in migraine patients. Correlation of FC changes with true clinical phases in spontaneous migraine would validate the utility of this model.
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Affiliation(s)
- Daniele Martinelli
- Headache Science Center, IRCCS Mondino Foundation, 27100 Pavia, Italy; (R.D.I.); (M.A.); (G.S.); (C.T.)
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy; (A.P.); (C.A.M.G.W.-K.)
| | - Gloria Castellazzi
- NMR Research Unit Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, Faculty of Brain Sciences, London WC1N3BG, UK;
- Department of Electrical Computer and Biomedical Engineering, University of Pavia, 27100 Pavia, Italy
- IRCCS Mondino Foundation, 27100 Pavia, Italy
| | - Roberto De Icco
- Headache Science Center, IRCCS Mondino Foundation, 27100 Pavia, Italy; (R.D.I.); (M.A.); (G.S.); (C.T.)
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy; (A.P.); (C.A.M.G.W.-K.)
| | - Ana Bacila
- Center of Advance Imaging and Radiomics, IRCCS Mondino Foundation, 27100 Pavia, Italy; (A.B.); (A.F.)
| | - Marta Allena
- Headache Science Center, IRCCS Mondino Foundation, 27100 Pavia, Italy; (R.D.I.); (M.A.); (G.S.); (C.T.)
| | - Arianna Faggioli
- Center of Advance Imaging and Radiomics, IRCCS Mondino Foundation, 27100 Pavia, Italy; (A.B.); (A.F.)
| | - Grazia Sances
- Headache Science Center, IRCCS Mondino Foundation, 27100 Pavia, Italy; (R.D.I.); (M.A.); (G.S.); (C.T.)
| | - Anna Pichiecchio
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy; (A.P.); (C.A.M.G.W.-K.)
- Center of Advance Imaging and Radiomics, IRCCS Mondino Foundation, 27100 Pavia, Italy; (A.B.); (A.F.)
| | - David Borsook
- Centre for Pain and The Brain Boston Children’s Hospital and Massachussetts General Hospital (MGH) Harvard Medical School, Boston, MA 02115, USA;
| | - Claudia A. M. Gandini Wheeler-Kingshott
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy; (A.P.); (C.A.M.G.W.-K.)
- NMR Research Unit Queen Square MS Centre, Department of Neuroinflammation, UCL Institute of Neurology, Faculty of Brain Sciences, London WC1N3BG, UK;
| | - Cristina Tassorelli
- Headache Science Center, IRCCS Mondino Foundation, 27100 Pavia, Italy; (R.D.I.); (M.A.); (G.S.); (C.T.)
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy; (A.P.); (C.A.M.G.W.-K.)
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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: 19] [Impact Index Per Article: 4.8] [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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21
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Peek AL, Rebbeck T, Puts NAJ, Watson J, Aguila MER, Leaver AM. Brain GABA and glutamate levels across pain conditions: A systematic literature review and meta-analysis of 1H-MRS studies using the MRS-Q quality assessment tool. Neuroimage 2020; 210:116532. [DOI: 10.1016/j.neuroimage.2020.116532] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Revised: 12/06/2019] [Accepted: 01/08/2020] [Indexed: 12/24/2022] Open
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Abnormal alpha band power in the dynamic pain connectome is a marker of chronic pain with a neuropathic component. NEUROIMAGE-CLINICAL 2020; 26:102241. [PMID: 32203904 PMCID: PMC7090370 DOI: 10.1016/j.nicl.2020.102241] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 02/25/2020] [Accepted: 03/10/2020] [Indexed: 01/08/2023]
Abstract
High theta and low gamma activity in the dynamic pain connectome is linked to chronic pain. High alpha-band activity is present when neuropathic pain is likely. Spectral frequency band strength distinguish neuropathic from non-neuropathic pain.
We previously identified alpha frequency slowing and beta attenuation in the dynamic pain connectome related to pain severity and interference in patients with multiple sclerosis-related neuropathic pain (NP). Here, we determined whether these abnormalities, are markers of aberrant temporal dynamics in non-neuropathic inflammatory pain (non-NP) or when NP is also suspected. We measured resting-state magnetoencephalography (MEG) spectral density in 45 people (17 females, 28 males) with chronic back pain due to ankylosing spondylitis (AS) and 38 age/sex matched healthy controls. We used painDETECT scores to divide the chronic pain group into those with only non-NP (NNP) and those who likely also had a component of NP in addition to their inflammatory pain. We also assessed pain severity, pain interference, and disease activity with the Brief Pain Inventory and Bath AS Disease Activity Index (BASDAI). We examined spectral power in the dynamic pain connectome, including nodes of the ascending nociceptive pathway (ANP), default mode (DMN), and salience networks (SN). Compared to the healthy controls, the AS patients exhibited increased theta power in the DMN and decreased low-gamma power in the DMN and ANP, but did not exhibit beta-band attenuation or peak-alpha slowing. The NNP patients were not different from HCs. Compared to both healthy controls and NNP, NP patients had increased alpha power in the ANP. Increased alpha power within the ANP was associated with reduced BASDAI in the NNP group, and increased pain in the mixed-NP group within the DMN, SN, and ANP. Thus, high theta and low gamma activity may be markers of chronic pain but high alpha-band activity may relate to particular features of neuropathic chronic pain.
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23
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Bismuth J, Vialatte F, Lefaucheur JP. Relieving peripheral neuropathic pain by increasing the power-ratio of low-β over high-β activities in the central cortical region with EEG-based neurofeedback: Study protocol for a controlled pilot trial (SMRPain study). Neurophysiol Clin 2020; 50:5-20. [DOI: 10.1016/j.neucli.2019.12.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 12/16/2019] [Accepted: 12/17/2019] [Indexed: 12/27/2022] Open
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24
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Vierck C. Mechanisms of Below-Level Pain Following Spinal Cord Injury (SCI). THE JOURNAL OF PAIN 2019; 21:262-280. [PMID: 31493490 DOI: 10.1016/j.jpain.2019.08.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 07/05/2019] [Accepted: 08/07/2019] [Indexed: 12/18/2022]
Abstract
Mechanisms of below-level pain are discoverable as neural adaptations rostral to spinal injury. Accordingly, the strategy of investigations summarized here has been to characterize behavioral and neural responses to below-level stimulation over time following selective lesions of spinal gray and/or white matter. Assessments of human pain and the pain sensitivity of humans and laboratory animals following spinal injury have revealed common disruptions of pain processing. Interruption of the spinothalamic pathway partially deafferents nocireceptive cerebral neurons, rendering them spontaneously active and hypersensitive to remaining inputs. The spontaneous activity among these neurons is disorganized and unlikely to generate pain. However, activation of these neurons by their remaining inputs can result in pain. Also, injury to spinal gray matter results in a cascade of secondary events, including excitotoxicity, with rostral propagation of excitatory influences that contribute to chronic pain. Establishment and maintenance of below-level pain results from combined influences of injured and spared axons in the spinal white matter and injured neurons in spinal gray matter on processing of nociception by hyperexcitable cerebral neurons that are partially deafferented. A model of spinal stenosis suggests that ischemic injury to the core spinal region can generate below-level pain. Additional questions are raised about demyelination, epileptic discharge, autonomic activation, prolonged activity of C nocireceptive neurons, and thalamocortical plasticity in the generation of below-level pain. PERSPECTIVE: An understanding of mechanisms can direct therapeutic approaches to prevent development of below-level pain or arrest it following spinal cord injury. Among the possibilities covered here are surgical and other means of attenuating gray matter excitotoxicity and ascending propagation of excitatory influences from spinal lesions to thalamocortical systems involved in pain encoding and arousal.
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Affiliation(s)
- Chuck Vierck
- Department of Neuroscience, University of Florida College of Medicine and McKnight Brain Institute, Gainesville, Florida.
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25
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Alshelh Z, Mills EP, Kosanovic D, Di Pietro F, Macey PM, Vickers ER, Henderson LA. Effects of the glial modulator palmitoylethanolamide on chronic pain intensity and brain function. J Pain Res 2019; 12:2427-2439. [PMID: 31447580 PMCID: PMC6683964 DOI: 10.2147/jpr.s209657] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 07/09/2019] [Indexed: 12/26/2022] Open
Abstract
Background: Chronic neuropathic pain (NP) is a complex disease that results from damage or presumed damage to the somatosensory nervous system. Current treatment regimens are often ineffective. The major impediment in developing effective treatments is our limited understanding of the underlying mechanisms. Preclinical evidence suggests that glial changes are crucial for the development of NP and a recent study reported oscillatory activity differences within the ascending pain pathway at frequencies similar to that of cyclic gliotransmission in NP. Furthermore, there is evidence that glial modifying medications may be effective in treating NP. The aim of this Phase I open-label clinical trial is to determine whether glial modifying medication palmitoylethanolamide (PEA) will reduce NP and whether this is associated with reductions in oscillatory activity within the pain pathway. Methods: We investigated whether 6 weeks of PEA treatment would reduce pain and infra-slow oscillatory activity within the ascending trigeminal pathway in 22 individuals (17 females) with chronic orofacial NP. Results: PEA reduced pain in 16 (73%) of the 22 subjects, 11 subjects showed pain reduction of over 20%. Whilst both the responders and non-responders showed reductions in infra-slow oscillatory activity where orofacial nociceptor afferents terminate in the brainstem, only responders displayed reductions in the thalamus. Furthermore, functional connections between the brainstem and thalamus were altered only in responders. Conclusion: PEA is effective at relieving NP. This reduction is coupled to a reduction in resting oscillations along the ascending pain pathway that are likely driven by rhythmic astrocytic gliotransmission.
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Affiliation(s)
- Zeynab Alshelh
- Department of Anatomy and Histology, University of Sydney, Sydney, NSW, Australia
| | - Emily P Mills
- Department of Anatomy and Histology, University of Sydney, Sydney, NSW, Australia
| | - Danny Kosanovic
- Department of Anatomy and Histology, University of Sydney, Sydney, NSW, Australia
| | - Flavia Di Pietro
- Department of Anatomy and Histology, University of Sydney, Sydney, NSW, Australia
| | - Paul M Macey
- School of Nursing and Brain Research Institute, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, CA, USA
| | - E Russell Vickers
- Department of Anatomy and Histology, University of Sydney, Sydney, NSW, Australia
| | - Luke A Henderson
- Department of Anatomy and Histology, University of Sydney, Sydney, NSW, Australia
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26
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Neuropathic pain and pain interference are linked to alpha-band slowing and reduced beta-band magnetoencephalography activity within the dynamic pain connectome in patients with multiple sclerosis. Pain 2018; 160:187-197. [DOI: 10.1097/j.pain.0000000000001391] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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27
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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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28
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Di Pietro F, Macey PM, Rae CD, Alshelh Z, Macefield VG, Vickers ER, Henderson LA. The relationship between thalamic GABA content and resting cortical rhythm in neuropathic pain. Hum Brain Mapp 2018; 39:1945-1956. [PMID: 29341331 DOI: 10.1002/hbm.23973] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2017] [Revised: 12/14/2017] [Accepted: 01/05/2018] [Indexed: 12/21/2022] Open
Abstract
Recurrent thalamocortical connections are integral to the generation of brain rhythms and it is thought that the inhibitory action of the thalamic reticular nucleus is critical in setting these rhythms. Our work and others' has suggested that chronic pain that develops following nerve injury, that is, neuropathic pain, results from altered thalamocortical rhythm, although whether this dysrhythmia is associated with thalamic inhibitory function remains unknown. In this investigation, we used electroencephalography and magnetic resonance spectroscopy to investigate cortical power and thalamic GABAergic concentration in 20 patients with neuropathic pain and 20 pain-free controls. First, we found thalamocortical dysrhythmia in chronic orofacial neuropathic pain; patients displayed greater power than controls over the 4-25 Hz frequency range, most marked in the theta and low alpha bands. Furthermore, sensorimotor cortex displayed a strong positive correlation between cortical power and pain intensity. Interestingly, we found no difference in thalamic GABA concentration between pain subjects and control subjects. However, we demonstrated significant linear relationships between thalamic GABA concentration and enhanced cortical power in pain subjects but not controls. Whilst the difference in relationship between thalamic GABA concentration and resting brain rhythm between chronic pain and control subjects does not prove a cause and effect link, it is consistent with a role for thalamic inhibitory neurotransmitter release, possibly from the thalamic reticular nucleus, in altered brain rhythms in individuals with chronic neuropathic pain.
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Affiliation(s)
- Flavia Di Pietro
- Department of Anatomy and Histology, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Paul M Macey
- UCLA School of Nursing and Brain Research Institute, University of California, Los Angeles, California
| | | | - Zeynab Alshelh
- Department of Anatomy and Histology, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Vaughan G Macefield
- Neuroscience Research Australia, Sydney, Australia.,College of Medicine, Mohammed Bin Rashid University of Medicine & Health Sciences, Dubai, United Arab Emirates
| | - E Russell Vickers
- Department of Anatomy and Histology, Sydney Medical School, University of Sydney, Sydney, Australia
| | - Luke A Henderson
- Department of Anatomy and Histology, Sydney Medical School, University of Sydney, Sydney, Australia
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