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Velickovic Z, Radunovic G. Repetitive Transcranial Magnetic Stimulation in Fibromyalgia: Exploring the Necessity of Neuronavigation for Targeting New Brain Regions. J Pers Med 2024; 14:662. [PMID: 38929883 PMCID: PMC11204413 DOI: 10.3390/jpm14060662] [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: 05/16/2024] [Revised: 06/15/2024] [Accepted: 06/18/2024] [Indexed: 06/28/2024] Open
Abstract
Fibromyalgia and osteoarthritis are among the most prevalent rheumatic conditions worldwide. Nonpharmacological interventions have gained scientific endorsements as the preferred initial treatments before resorting to pharmacological modalities. Repetitive transcranial magnetic stimulation (rTMS) is among the most widely researched neuromodulation techniques, though it has not yet been officially recommended for fibromyalgia. This review aims to summarize the current evidence supporting rTMS for treating various fibromyalgia symptoms. Recent findings: High-frequency rTMS directed at the primary motor cortex (M1) has the strongest support in the literature for reducing pain intensity, with new research examining its long-term effectiveness. Nonetheless, some individuals may not respond to M1-targeted rTMS, and symptoms beyond pain can be prominent. Ongoing research aims to improve the efficacy of rTMS by exploring new brain targets, using innovative stimulation parameters, incorporating neuronavigation, and better identifying patients likely to benefit from this treatment. Summary: Noninvasive brain stimulation with rTMS over M1 is a well-tolerated treatment that can improve chronic pain and overall quality of life in fibromyalgia patients. However, the data are highly heterogeneous, with a limited level of evidence, posing a significant challenge to the inclusion of rTMS in official treatment guidelines. Research is ongoing to enhance its effectiveness, with future perspectives exploring its impact by targeting additional areas of the brain such as the medial prefrontal cortex, anterior cingulate cortex, and inferior parietal lobe, as well as selecting the right patients who could benefit from this treatment.
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Affiliation(s)
| | - Goran Radunovic
- Institute of Rheumatology, Resavska 69, 11000 Belgrade, Serbia;
- School of Medicine, University of Belgrade, Dr Subotića 1, 11000 Belgrade, Serbia
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2
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Shigetoh H, Koga M, Tanaka Y, Hirakawa Y, Morioka S. Characterizing clinical progression in patients with musculoskeletal pain by pain severity and central sensitization-related symptoms. Sci Rep 2024; 14:4873. [PMID: 38418550 PMCID: PMC10902372 DOI: 10.1038/s41598-024-55290-4] [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: 04/16/2023] [Accepted: 02/22/2024] [Indexed: 03/01/2024] Open
Abstract
Central sensitization-related symptoms (CSS) are associated with the severity and progression of pain. The relationship between the severity of pain/CSS and clinical progresses remains unclear. This multicenter, collaborative, longitudinal study aimed to characterize the clinical outcomes of patients with musculoskeletal pain by classifying subgroups based on the severity of pain/CSS and examining changes in subgroups over time. We measured the pain intensity, CSS, catastrophic thinking, and body perception disturbance in 435 patients with musculoskeletal pain. Reevaluation of patients after one month included 166 patients for pain intensity outcome and 110 for both pain intensity and CSS outcome analysis. We classified the patients into four groups (mild pain/CSS, severe pain/mild CSS, severe pain/CSS, and mild pain/severe CSS groups) and performed multiple comparison analyses to reveal the differences between the CSS severity groups. Additionally, we performed the adjusted residual chi-square to identify the number of patients with pain improvement, group transition, changing pain, and CSS pattern groups at baseline. The most characteristic result was that the mild and severe CSS groups showed worsening pain. Moreover, many of the group transitions were to the same group, with a few transitioning to a group with mild pain/CSS. Our findings suggest that the severity and improvement of CSS influence pain prognosis.
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Affiliation(s)
- Hayato Shigetoh
- Department of Physical Therapy, Faculty of Health Science, Kyoto Tachibana University, Kyoto, 607-8175, Japan.
- Neurorehabilitation Research Center, Kio University, Nara, 635-0832, Japan.
| | - Masayuki Koga
- Department of Neurorehabilitation, Graduate School of Health Sciences, Kio University, Nara, 635-0832, Japan
| | - Yoichi Tanaka
- Neurorehabilitation Research Center, Kio University, Nara, 635-0832, Japan
| | - Yoshiyuki Hirakawa
- Neurorehabilitation Research Center, Kio University, Nara, 635-0832, Japan
| | - Shu Morioka
- Neurorehabilitation Research Center, Kio University, Nara, 635-0832, Japan
- Department of Neurorehabilitation, Graduate School of Health Sciences, Kio University, Nara, 635-0832, Japan
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3
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Ghavidel-Parsa B, Bidari A. The crosstalk of the pathophysiologic models in fibromyalgia. Clin Rheumatol 2023; 42:3177-3187. [PMID: 37749410 DOI: 10.1007/s10067-023-06778-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 09/12/2023] [Accepted: 09/16/2023] [Indexed: 09/27/2023]
Abstract
Fibromyalgia (FM) is a heterogeneous condition with various mechanisms (endotype) and manifestations (phenotypes). Many worthy endeavors have been dedicated to exploring the main trajectories of FM pathogenesis, depicted as the models of FM development. The Imbalance of Threat and Soothing Systems (FITSS) model, which is an advancing psychosocial form of the "central sensitization" model, and autonomic nervous system (ANS) model, besides new discoveries of potential pathways for FM development such as autoimmunity, small fiber pathology, and gut-brain axis currently comprise all our knowledge assets about FM pathogenesis. The pathophysiology of fibromyalgia is too complex to justify with one model, one main loop of pathogenesis, and one terminator. It appears that the variable FM models could justify some phenotypes of FM. Currently, our knowledge about FM pathogenesis and trying to match the different pathways and links mimic solving a puzzle in the hands of beginners. Until unraveling many missed interconnections and formulas between numerous scrambled pieces of the FM puzzle, proposing an integrated model seems not possible. This review focuses on the main trajectories of FM pathogenesis proposed thus far and tries to illuminate the crosstalking between them. We also propose the subgrouping FM into more homogenous categories based on the endotype-phenotype characteristics. It could provide a more pragmatic approach toward understanding of the diverse network of FM pathogenesis as well as the personalized stratification of FM. Key Points • The disentangled nature of FM pathogenesis escapes from embracing under one integrated model. • There appears to be no way for formulizing FM pathogenesis except the acknowledgment of the different pathways and their crosstalk explored as yet. • Acknowledging the different endotypes/phenotypes of FM spectrum and classifying them into more homogenous groups can help to the pragmatic approach to FM.
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Affiliation(s)
- Banafsheh Ghavidel-Parsa
- Rheumatology Research Center, Razi Hospital, School of Medicine, Guilan University of Medical Sciences, Sardar Jangal St, Rasht, Iran.
| | - Ali Bidari
- Department of Rheumatology, Iran University of Medical Sciences, Tehran, Iran
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4
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Fanton S, Menezes J, Krock E, Sandström A, Tour J, Sandor K, Jurczak A, Hunt M, Baharpoor A, Kadetoff D, Jensen KB, Fransson P, Ellerbrock I, Sitnikov R, Svensson CI, Kosek E. Anti-satellite glia cell IgG antibodies in fibromyalgia patients are related to symptom severity and to metabolite concentrations in thalamus and rostral anterior cingulate cortex. Brain Behav Immun 2023; 114:371-382. [PMID: 37683961 DOI: 10.1016/j.bbi.2023.09.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 08/29/2023] [Accepted: 09/05/2023] [Indexed: 09/10/2023] Open
Abstract
Recent translational work has shown that fibromyalgia might be an autoimmune condition with pathogenic mechanisms mediated by a peripheral, pain-inducing action of immunoglobulin G (IgG) antibodies binding to satellite glia cells (SGC) in the dorsal root ganglia. A first clinical assessment of the postulated autoimmunity showed that fibromyalgia subjects (FMS) had elevated levels of antibodies against SGC (termed anti-SGC IgG) compared to healthy controls and that anti-SGC IgG were associated with a more severe disease status. The overarching aim of the current study was to determine whether the role of anti-SGC IgG in driving pain is exclusively through peripheral mechanisms, as indirectly shown so far, or could be attributed also to central mechanisms. To this end, we wanted to first confirm, in a larger cohort of FMS, the relation between anti-SGC IgG and pain-related clinical measures. Secondly, we explored the associations of these autoantibodies with brain metabolite concentrations (assessed via magnetic resonance spectroscopy, MRS) and pressure-evoked cerebral pain processing (assessed via functional magnetic resonance imaging, fMRI) in FMS. Proton MRS was performed in the thalamus and rostral anterior cingulate cortex (rACC) of FMS and concentrations of a wide spectrum of metabolites were assessed. During fMRI, FMS received individually calibrated painful pressure stimuli corresponding to low and high pain intensities. Our results confirmed a positive correlation between anti-SGC IgG and clinical measures assessing condition severity. Additionally, FMS with high anti-SGC IgG levels had higher pain intensity and a worse disease status than FMS with low anti-SGC IgG levels. Further, anti-SGC IgG levels negatively correlated with metabolites such as scyllo-inositol in thalamus and rACC as well as with total choline and macromolecule 12 in thalamus, thus linking anti-SGC IgG levels to the concentration of metabolites in the brain of FMS. However, anti-SGC IgG levels in FMS were not associated with the sensitivity to pressure pain or the cerebral processing of evoked pressure pain. Taken together, our results suggest that anti-SGC IgG might be clinically relevant for spontaneous, non-evoked pain. Our current and previous translational and clinical findings could provide a rationale to try new antibody-related treatments in FMS.
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Affiliation(s)
- Silvia Fanton
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden.
| | - Joana Menezes
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Emerson Krock
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden; Faculty of Dental Medicine and Oral Health Sciences, Alan Edwards Centre for Research on Pain, McGill University, Montreal, Canada
| | - Angelica Sandström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; Department of Radiology, Massachusetts General Hospital, A.A. Martinos Center for Biomedical Imaging, Harvard Medical School, Boston, MA, USA
| | - Jeanette Tour
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Katalin Sandor
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Alexandra Jurczak
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Matthew Hunt
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Azar Baharpoor
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Diana Kadetoff
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; Stockholm Spine Center, Löwenströmska Hospital, Upplands Väsby, Sweden
| | - Karin B Jensen
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Peter Fransson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Isabel Ellerbrock
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Rouslan Sitnikov
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; MRI Research Center, Karolinska University Hospital, Stockholm, Sweden
| | - Camilla I Svensson
- Department of Physiology and Pharmacology, Center for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Eva Kosek
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden; Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
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Schmidt H, Blechschmidt V. [Nociplastic pain in research and practice : Overview of biopsychosocial principles, possibilities and difficulties]. Schmerz 2023:10.1007/s00482-023-00734-5. [PMID: 37432482 DOI: 10.1007/s00482-023-00734-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 05/24/2023] [Accepted: 05/25/2023] [Indexed: 07/12/2023]
Abstract
Traditionally, two mechanistic pain categories were distinguished: nociceptive and neuropathic pain. After the definitions of these two mechanistic descriptors were refined more precisely in the International Association for the Study of Pain (IASP) taxonomy in 2011, a large group of patients remained whose pain could not be assigned to either of the two categories. Nociplastic pain was therefore proposed as a third mechanistic descriptor in 2016. This review article presents the current state of the integration of nociplastic pain into research and clinical practice. In particular, the possibilities and difficulties of applying this concept are addressed from a human and animal experimental research perspective.
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Affiliation(s)
- Hannah Schmidt
- Abteilung für Neurophysiologie, Mannheimer Zentrum für Translationale Neurowissenschaft, Universität Heidelberg, Ludolf-Krehl-Str. 13-17, 68167, Mannheim, Deutschland
| | - Vivian Blechschmidt
- Abteilung für Neurophysiologie, Mannheimer Zentrum für Translationale Neurowissenschaft, Universität Heidelberg, Ludolf-Krehl-Str. 13-17, 68167, Mannheim, Deutschland.
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Carle-Toulemonde G, Goutte J, Do-Quang-Cantagrel N, Mouchabac S, Joly C, Garcin B. Overall comorbidities in functional neurological disorder: A narrative review. L'ENCEPHALE 2023:S0013-7006(23)00086-6. [PMID: 37414721 DOI: 10.1016/j.encep.2023.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 06/06/2023] [Indexed: 07/08/2023]
Abstract
INTRODUCTION The importance to assess and include the frequent comorbidities in the personalised care management plan of patients with functional neurological disorders (FND) has arisen through the years. FND patients are not only complaining from motor and/or sensory symptoms. They also report some non-specific symptoms that participate to the burden of FND. In this narrative review, we aim to better describe these comorbidities in terms of prevalence, clinical characteristics and their variability depending on the subtype of FND. METHODS The literature was searched for on Medline and PubMed. The search was narrowed to articles between 2000 and 2022. RESULTS Fatigue is the most common symptom reported in relation to FND (from 47 to 93%), followed by cognitive symptoms (from 80 to 85%). Psychiatric disorders are reported in 40 to 100% FND patients, depending on the FND subtype (functional motor disorder [FMD], functional dissociative seizures [FDS]…) but also on the type of psychiatric disorder (anxiety disorders being the most frequent, followed by mood disorders and neurodevelopmental disorders). Stress factors such as childhood trauma exposure (emotional neglect and physical abuse predominantly) have also been identified in up to 75% of FND patients, along with maladaptive coping strategies. Organic disorders are commonly reported in FND, such as neurological disorders (including epilepsy in FDS [20%] and FMD in Parkinson's Disease [7%]). Somatic symptom disorders including chronic pain syndromes are frequently associated to FND (about 50%). To be noted, recent data also suggest a high comorbidity between FND and hypermobile Ehlers Danlos Syndrome (about 55%). CONCLUSION Put together, this narrative review highlights the high burden of FND patients, not only due to somatosensory alterations but also by considering the frequent comorbidities reported. Thus, such comorbidities must be taken into consideration when defining the FND personalised care management strategy for the patients.
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Affiliation(s)
| | - Julie Goutte
- Internal Medicine Department, Saint-Etienne University Hospital, Saint-Priest-en-Jarez, France
| | | | - Stéphane Mouchabac
- Sorbonne University, Department of Psychiatry, AP-HP, Saint-Antoine University Hospital, Paris, France
| | - Charlotte Joly
- Neurology Department, Assistance Publique-Hôpitaux de Paris, AP-HP Avicenne University Hospital, Bobigny, France
| | - Béatrice Garcin
- Neurology Department, Assistance Publique-Hôpitaux de Paris, AP-HP Avicenne University Hospital, Bobigny, France
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7
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Bułdyś K, Górnicki T, Kałka D, Szuster E, Biernikiewicz M, Markuszewski L, Sobieszczańska M. What Do We Know about Nociplastic Pain? Healthcare (Basel) 2023; 11:1794. [PMID: 37372912 PMCID: PMC10298569 DOI: 10.3390/healthcare11121794] [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: 03/22/2023] [Revised: 06/13/2023] [Accepted: 06/16/2023] [Indexed: 06/29/2023] Open
Abstract
Nociplastic pain is a recently distinguished type of pain, distinct from neuropathic and nociceptive pain, and is well described in the literature. It is often mistaken for central sensitization. Pathophysiology has not been clearly established with regard to alteration of the concentration of spinal fluid elements, the structure of the white and gray matter of the brain, and psychological aspects. Many different diagnostic tools, i.e., the painDETECT and Douleur Neuropathique 4 questionnaires, have been developed to diagnose neuropathic pain, but they can also be applied for nociplastic pain; however, more standardized instruments are still needed in order to assess its occurrence and clinical presentation. Numerous studies have shown that nociplastic pain is present in many different diseases such as fibromyalgia, complex regional pain syndrome type 1, and irritable bowel syndrome. Current pharmacological and nonpharmacological treatments for nociceptive and neuropathic pain are not entirely suitable for treating nociplastic pain. There is an ongoing effort to establish the most efficient way to manage it. The significance of this field has led to several clinical trials being carried out in a short time. The aim of this narrative review was to discuss the currently available evidence on pathophysiology, associated diseases, treatment possibilities, and clinical trials. It is important that physicians widely discuss and acknowledge this relatively new concept in order to provide optimized pain control for patients.
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Affiliation(s)
- Kacper Bułdyś
- Faculty of Medical Sciences and Health Sciences, Kazimierz Pulaski University of Technology and Humanities in Radom, 26-600 Radom, Poland
| | - Tomasz Górnicki
- Faculty of Medicine, Wroclaw Medical University, 50-367 Wroclaw, Poland
| | - Dariusz Kałka
- Faculty of Physiotherapy, Wroclaw University of Health and Sport Sciences, 51-612 Wroclaw, Poland
- Men’s Health Centre in Wrocław, 53-151 Wroclaw, Poland
| | - Ewa Szuster
- Cardiosexology Students Club, Wroclaw Medical University, 50-368 Wroclaw, Poland
| | | | - Leszek Markuszewski
- Faculty of Medical Sciences and Health Sciences, Kazimierz Pulaski University of Technology and Humanities in Radom, 26-600 Radom, Poland
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8
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Sunzini F, Schrepf A, Clauw DJ, Basu N. The Biology of Pain: Through the Rheumatology Lens. Arthritis Rheumatol 2023; 75:650-660. [PMID: 36599071 DOI: 10.1002/art.42429] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 11/07/2022] [Accepted: 12/20/2022] [Indexed: 01/06/2023]
Abstract
Chronic pain is a major socioeconomic burden globally. The most frequent origin of chronic pain is musculoskeletal. In inflammatory musculoskeletal diseases such as rheumatoid arthritis (RA), chronic pain is a primary determinant of deleterious quality of life. The pivotal role of peripheral inflammation in the initiation and perpetuation of nociceptive pain is well-established among patients with musculoskeletal diseases. However, the persistence of pain, even after the apparent resolution of peripheral inflammation, alludes to the coexistence of different pain states. Recent advances in neurobiology have highlighted the importance of nociplastic pain mechanisms. In this review we aimed to explore the biology of pain with a particular focus on nociplastic pain in RA.
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Affiliation(s)
- Flavia Sunzini
- Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
| | - Andrew Schrepf
- Department of Anesthesiology, Chronic Pain and Fatigue Research Center, University of Michigan Medical School, Ann Arbor
| | - Daniel J Clauw
- Department of Anesthesiology, Chronic Pain and Fatigue Research Center, University of Michigan Medical School, Ann Arbor
| | - Neil Basu
- Institute of Infection, Immunity and Inflammation, University of Glasgow, UK
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9
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Ocay DD, Ross BD, Moscaritolo L, Ahmed N, Ouellet JA, Ferland CE, Ingelmo PM. The Psychosocial Characteristics and Somatosensory Function of Children and Adolescents Who Meet the Criteria for Chronic Nociplastic Pain. J Pain Res 2023; 16:487-500. [PMID: 36815125 PMCID: PMC9939946 DOI: 10.2147/jpr.s397829] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 02/10/2023] [Indexed: 02/17/2023] Open
Abstract
Purpose Nociplastic pain distinguishes individuals with pain and hypersensitivity in body regions with apparently normal tissues, without any signs of neuropathy, but with contribution of central and/or peripheral sensitization. There is a lack of literature describing nociplastic pain in the pediatric population. The objective of this study was to investigate the differences between pediatric patients with nociplastic pain compared with patients with non-nociplastic pain. Patients and Methods This study included 414 pediatric patients followed at an interdisciplinary centre for complex pain. All patients underwent an exhaustive pain assessment consisting of face-to-face interviews, validated self-report questionnaires and quantitative sensory testing. Recently established criteria for chronic nociplastic pain, and quantitative sensory testing was used to describe and stratify our cohort. Results One hundred and sixty-five patients (40%) were stratified as having possible nociplastic pain and two hundred and forty-nine (60%) patients, as non-nociplastic pain. Patients with nociplastic pain displayed pain hypersensitivity in the region of pain, more symptoms of panic and social phobia, and worse sleep quality than patients with non-nociplastic pain. The proportion of patients achieving a meaningful clinical outcome after completion of their treatment (medications, physiotherapy, psychology, nursing, social worker, and/or interventional procedures) was lower in patients with nociplastic pain (62%) than those without nociplastic pain (86%). Conclusion Our results suggest that patients who meet the criteria for nociplastic pain can be identified in a population of children and adolescents being treated in a center for complex pain. Combining screening with validated questionnaires and quantitative sensory testing facilitates the phenotyping and graded severity of patients with nociplastic pain in daily clinical practice.
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Affiliation(s)
- Don Daniel Ocay
- Department of Experimental Surgery, McGill University, Montreal, QC, Canada,Department of Clinical Research, Shriners Hospitals for Children Canada, Montreal, QC, Canada,Edwards Family Interdisciplinary Centre for Complex Pain, Montreal Children’s Hospital, Montreal, QC, Canada
| | - Brendan D Ross
- Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Lorenzo Moscaritolo
- Edwards Family Interdisciplinary Centre for Complex Pain, Montreal Children’s Hospital, Montreal, QC, Canada
| | - Nabeel Ahmed
- Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Jean A Ouellet
- Department of Clinical Research, Shriners Hospitals for Children Canada, Montreal, QC, Canada,Department of Pediatric Surgery, McGill University, Montreal, QC, Canada,Department of Anesthesia, McGill University, Montreal, QC, Canada,Research Institute-McGill University Health Centre, Montreal, QC, Canada
| | - Catherine E Ferland
- Department of Experimental Surgery, McGill University, Montreal, QC, Canada,Department of Clinical Research, Shriners Hospitals for Children Canada, Montreal, QC, Canada,Edwards Family Interdisciplinary Centre for Complex Pain, Montreal Children’s Hospital, Montreal, QC, Canada,Department of Anesthesia, McGill University, Montreal, QC, Canada,Research Institute-McGill University Health Centre, Montreal, QC, Canada,Alan Edwards Research Center for Pain, McGill University, Montreal, QC, Canada
| | - Pablo M Ingelmo
- Edwards Family Interdisciplinary Centre for Complex Pain, Montreal Children’s Hospital, Montreal, QC, Canada,Department of Anesthesia, McGill University, Montreal, QC, Canada,Research Institute-McGill University Health Centre, Montreal, QC, Canada,Alan Edwards Research Center for Pain, McGill University, Montreal, QC, Canada,Correspondence: Pablo M Ingelmo, Edwards Family Interdisciplinary Centre for Complex Pain, Montreal Children’s Hospital, B02-3525-1001 Boulevard Décarie, Montreal, H4A 13J, Canada, Tel +1 514 412-4448, Fax +1 514 412-4341, Email
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10
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Kobayashi S, O'Hashi K, Kobayashi M. Repetitive nociceptive stimulation increases spontaneous neural activation similar to nociception-induced activity in mouse insular cortex. Sci Rep 2022; 12:15190. [PMID: 36071208 PMCID: PMC9452502 DOI: 10.1038/s41598-022-19562-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 08/31/2022] [Indexed: 11/09/2022] Open
Abstract
Recent noninvasive neuroimaging technology has revealed that spatiotemporal patterns of cortical spontaneous activity observed in chronic pain patients are different from those in healthy subjects, suggesting that the spontaneous cortical activity plays a key role in the induction and/or maintenance of chronic pain. However, the mechanisms of the spontaneously emerging activities supposed to be induced by nociceptive inputs remain to be established. In the present study, we investigated spontaneous cortical activities in sessions before and after electrical stimulation of the periodontal ligament (PDL) by applying wide-field and two-photon calcium imaging to anesthetized GCaMP6s transgenic mice. First, we identified the sequential cortical activation patterns from the primary somatosensory and secondary somatosensory cortices to the insular cortex (IC) by PDL stimulation. We, then found that spontaneous IC activities that exhibited a similar spatiotemporal cortical pattern to evoked activities by PDL stimulation increased in the session after repetitive PDL stimulation. At the single-cell level, repetitive PDL stimulation augmented the synchronous neuronal activity. These results suggest that cortical plasticity induced by the repetitive stimulation leads to the frequent PDL stimulation-evoked-like spontaneous IC activation. This nociception-induced spontaneous activity in IC may be a part of mechanisms that induces chronic pain.
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Affiliation(s)
- Shutaro Kobayashi
- Department of Pharmacology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan.,Department of Oral Surgery, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan
| | - Kazunori O'Hashi
- Department of Pharmacology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan. .,Division of Oral and Craniomaxillofacial Research, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan. .,Department of Mental Disorder Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.
| | - Masayuki Kobayashi
- Department of Pharmacology, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan. .,Division of Oral and Craniomaxillofacial Research, Dental Research Center, Nihon University School of Dentistry, 1-8-13 Kanda-Surugadai, Chiyoda-ku, Tokyo, 101-8310, Japan. .,Molecular Imaging Research Center, RIKEN, 6-7-3 Minatojima-minamimachi, Chuo-ku, Kobe, 650-0047, Japan.
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11
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Heitmann H, Gil Ávila C, Nickel MM, Ta Dinh S, May ES, Tiemann L, Hohn VD, Tölle TR, Ploner M. Longitudinal resting-state electroencephalography in patients with chronic pain undergoing interdisciplinary multimodal pain therapy. Pain 2022; 163:e997-e1005. [PMID: 35050961 PMCID: PMC9393803 DOI: 10.1097/j.pain.0000000000002565] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/10/2021] [Accepted: 12/03/2021] [Indexed: 11/27/2022]
Abstract
ABSTRACT Chronic pain is a major healthcare issue posing a large burden on individuals and society. Converging lines of evidence indicate that chronic pain is associated with substantial changes of brain structure and function. However, it remains unclear which neuronal measures relate to changes of clinical parameters over time and could thus monitor chronic pain and treatment responses. We therefore performed a longitudinal study in which we assessed clinical characteristics and resting-state electroencephalography data of 41 patients with chronic pain before and 6 months after interdisciplinary multimodal pain therapy. We specifically assessed electroencephalography measures that have previously been shown to differ between patients with chronic pain and healthy people. These included the dominant peak frequency; the amplitudes of neuronal oscillations at theta, alpha, beta, and gamma frequencies; as well as graph theory-based measures of brain network organization. The results show that pain intensity, pain-related disability, and depression were significantly improved after interdisciplinary multimodal pain therapy. Bayesian hypothesis testing indicated that these clinical changes were not related to changes of the dominant peak frequency or amplitudes of oscillations at any frequency band. Clinical changes were, however, associated with an increase in global network efficiency at theta frequencies. Thus, changes in chronic pain might be reflected by global network changes in the theta band. These longitudinal insights further the understanding of the brain mechanisms of chronic pain. Beyond, they might help to identify biomarkers for the monitoring of chronic pain.
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Affiliation(s)
- Henrik Heitmann
- Technical University of Munich (TUM), School of Medicine, Department of Neurology, Munich, Germany
- TUM, School of Medicine, TUM-Neuroimaging Center, Munich, Germany
- TUM, School of Medicine, Center for Interdisciplinary Pain Medicine, Munich, Germany
| | - Cristina Gil Ávila
- Technical University of Munich (TUM), School of Medicine, Department of Neurology, Munich, Germany
- TUM, School of Medicine, TUM-Neuroimaging Center, Munich, Germany
| | - Moritz M. Nickel
- Technical University of Munich (TUM), School of Medicine, Department of Neurology, Munich, Germany
- TUM, School of Medicine, TUM-Neuroimaging Center, Munich, Germany
| | - Son Ta Dinh
- Technical University of Munich (TUM), School of Medicine, Department of Neurology, Munich, Germany
- TUM, School of Medicine, TUM-Neuroimaging Center, Munich, Germany
| | - Elisabeth S. May
- Technical University of Munich (TUM), School of Medicine, Department of Neurology, Munich, Germany
- TUM, School of Medicine, TUM-Neuroimaging Center, Munich, Germany
| | - Laura Tiemann
- Technical University of Munich (TUM), School of Medicine, Department of Neurology, Munich, Germany
- TUM, School of Medicine, TUM-Neuroimaging Center, Munich, Germany
| | - Vanessa D. Hohn
- Technical University of Munich (TUM), School of Medicine, Department of Neurology, Munich, Germany
- TUM, School of Medicine, TUM-Neuroimaging Center, Munich, Germany
| | - Thomas R. Tölle
- Technical University of Munich (TUM), School of Medicine, Department of Neurology, Munich, Germany
- TUM, School of Medicine, Center for Interdisciplinary Pain Medicine, Munich, Germany
| | - Markus Ploner
- Technical University of Munich (TUM), School of Medicine, Department of Neurology, Munich, Germany
- TUM, School of Medicine, TUM-Neuroimaging Center, Munich, Germany
- TUM, School of Medicine, Center for Interdisciplinary Pain Medicine, Munich, Germany
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12
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Fanton S, Altawil R, Ellerbrock I, Lampa J, Kosek E, Fransson P, Thompson WH. Multiple spatial scale mapping of time-resolved brain network reconfiguration during evoked pain in patients with rheumatoid arthritis. Front Neurosci 2022; 16:942136. [PMID: 36017179 PMCID: PMC9397124 DOI: 10.3389/fnins.2022.942136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Functional brain networks and the perception of pain can fluctuate over time. However, how the time-dependent reconfiguration of functional brain networks contributes to chronic pain remains largely unexplained. Here, we explored time-varying changes in brain network integration and segregation during pain over a disease-affected area (joint) compared to a neutral site (thumbnail) in 28 patients with rheumatoid arthritis (RA) in comparison with 22 healthy controls (HC). During functional magnetic resonance imaging, all subjects received individually calibrated pain pressures corresponding to visual analog scale 50 mm at joint and thumbnail. We implemented a novel approach to track changes of task-based network connectivity over time. Within this framework, we quantified measures of integration (participation coefficient, PC) and segregation (within-module degree z-score). Using these network measures at multiple spatial scales, both at the level of single nodes (brain regions) and communities (clusters of nodes), we found that PC at the community level was generally higher in RA patients compared to HC during and after painful pressure over the inflamed joint and corresponding site in HC. This shows that all brain communities integrate more in RA patients than in HC for time points following painful stimulation to a disease-relevant body site. However, the elevated community-related integration seen in patients appeared to not pertain uniquely to painful stimulation at the inflamed joint, but also at the neutral thumbnail, as integration and segregation at the community level did not differ across body sites in patients. Moreover, there was no specific nodal contribution to brain network integration or segregation. Altogether, our findings indicate widespread and persistent changes in network interaction in RA patients compared to HC in response to painful stimulation.
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Affiliation(s)
- Silvia Fanton
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Reem Altawil
- Rheumatology Unit, Department of Medicine, Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Isabel Ellerbrock
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Jon Lampa
- Rheumatology Unit, Department of Medicine, Center for Molecular Medicine, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Eva Kosek
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
- Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
| | - Peter Fransson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - William H. Thompson
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Division of Cognition and Communication, Department of Applied IT, University of Gothenburg, Gothenburg, Sweden
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13
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Martins D, Dipasquale O, Veronese M, Turkheimer F, Loggia ML, McMahon S, Howard MA, Williams SC. Transcriptional and cellular signatures of cortical morphometric remodelling in chronic pain. Pain 2022; 163:e759-e773. [PMID: 34561394 PMCID: PMC8940732 DOI: 10.1097/j.pain.0000000000002480] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 09/01/2021] [Accepted: 09/07/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT Chronic pain is a highly debilitating and difficult to treat condition, which affects the structure of the brain. Although the development of chronic pain is moderately heritable, how disease-related alterations at the microscopic genetic architecture drive macroscopic brain abnormalities is currently largely unknown. Here, we examined alterations in morphometric similarity (MS) and applied an integrative imaging transcriptomics approach to identify transcriptional and cellular correlates of these MS changes, in 3 independent small cohorts of patients with distinct chronic pain syndromes (knee osteoarthritis, low back pain, and fibromyalgia) and age-matched and sex-matched pain-free controls. We uncover a novel pattern of cortical MS remodelling involving mostly small-to-medium MS increases in the insula and limbic cortex (none of these changes survived stringent false discovery rate correction for the number of regions tested). This pattern of changes is different from that observed in patients with major depression and cuts across the boundaries of specific pain syndromes. By leveraging transcriptomic data from Allen Human Brain Atlas, we show that cortical MS remodelling in chronic pain spatially correlates with the brain-wide expression of genes related to pain and broadly involved in the glial immune response and neuronal plasticity. Our findings bridge levels to connect genes, cell classes, and biological pathways to in vivo imaging correlates of chronic pain. Although correlational, our data suggest that cortical remodelling in chronic pain might be shaped by multiple elements of the cellular architecture of the brain and identifies several pathways that could be prioritized in future genetic association or drug development studies.
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Affiliation(s)
- Daniel Martins
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Ottavia Dipasquale
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Mattia Veronese
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Federico Turkheimer
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Marco L. Loggia
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Harvard Medical School, Massachusetts General Hospital Boston, MA, United States
| | - Stephen McMahon
- Wolfson CARD, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Matthew A. Howard
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
| | - Steven C.R. Williams
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom
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14
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Sandström A, Ellerbrock I, Löfgren M, Altawil R, Bileviciute-Ljungar I, Lampa J, Kosek E. Distinct aberrations in cerebral pain processing differentiating patients with fibromyalgia from patients with rheumatoid arthritis. Pain 2022; 163:538-547. [PMID: 34224497 PMCID: PMC8832547 DOI: 10.1097/j.pain.0000000000002387] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 06/11/2021] [Accepted: 06/15/2021] [Indexed: 11/26/2022]
Abstract
ABSTRACT The current study used functional magnetic resonance imaging to directly compare disease-relevant cerebral pain processing in well-characterized patient cohorts of fibromyalgia (FM, nociplastic pain) and rheumatoid arthritis (RA, nociceptive pain). Secondary aims were to identify pain-related cerebral alterations related to the severity of clinical symptoms such as pain intensity, depression, and anxiety. Twenty-six patients with FM (without RA-comorbidity) and 31 patients with RA (without FM-comorbidity) underwent functional magnetic resonance imaging while stimulated with subjectively calibrated painful pressures corresponding to a pain sensation of 50 mm on a 100-mm visual analogue scale. Stimulation sites were at the most inflamed proximal interphalangeal joint in the left hand in patients with RA and the left thumbnail in patients with FM, 2 sites that have previously been shown to yield the same brain activation in healthy controls. The current results revealed disease-distinct differences during pain modulation in RA and FM. Specifically, in response to painful stimulation, patients with FM compared to patients with RA exhibited increased brain activation in bilateral inferior parietal lobe (IPL), left inferior frontal gyrus (IFG)/ventrolateral prefrontal cortex (vlPFC) encapsulating left dorsolateral prefrontal cortex, and right IFG/vlPFC. However, patients with RA compared to patients with FM exhibited increased functional connectivity (during painful stimulation) between right and left IPL and sensorimotor network and between left IPL and frontoparietal network. Within the FM group only, anxiety scores positively correlated with pain-related brain activation in left dorsolateral prefrontal cortex and right IFG/vlPFC, which further highlights the complex interaction between affective (ie, anxiety scores) and sensory (ie, cerebral pain processing) dimensions in this patient group.
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Affiliation(s)
- Angelica Sandström
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Isabel Ellerbrock
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
| | - Monika Löfgren
- Department of Clinical Sciences, Karolinska Institutet, Danderyd University Hospital, Stockholm, Sweden
| | - Reem Altawil
- Department of Medicine, Rheumatology Unit, Center for Molecular Medicine (CMM), Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Indre Bileviciute-Ljungar
- Department of Clinical Sciences, Karolinska Institutet, Danderyd University Hospital, Stockholm, Sweden
| | - Jon Lampa
- Department of Medicine, Rheumatology Unit, Center for Molecular Medicine (CMM), Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
| | - Eva Kosek
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
- Department of Neuroradiology, Karolinska University Hospital, Stockholm, Sweden
- Department of Surgical Sciences/Pain Research, Uppsala University, Uppsala, Sweden
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15
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Khoury S, Parisien M, Thompson SJ, Vachon-Presseau E, Roy M, Martinsen AE, Winsvold BS, Mundal IP, Zwart JA, Kania A, Mogil JS, Diatchenko L. Genome-wide analysis identifies impaired axonogenesis in chronic overlapping pain conditions. Brain 2021; 145:1111-1123. [PMID: 34788396 DOI: 10.1093/brain/awab359] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 07/08/2021] [Accepted: 08/20/2021] [Indexed: 11/12/2022] Open
Abstract
Chronic pain is often present at more than one anatomical location, leading to chronic overlapping pain conditions (COPC). Whether COPC represents a distinct pathophysiology from the occurrence of pain at only one site is unknown. Using genome-wide approaches, we compared genetic determinants of chronic single-site vs. multisite pain in the UK Biobank. We found that different genetic signals underlie chronic single-site and multisite pain with much stronger genetic contributions for the latter. Among 23 loci associated with multisite pain, 9 loci replicated in the HUNT cohort, with the DCC netrin-1 receptor (DCC) as the top gene. Functional genomics identified axonogenesis in brain tissues as the major contributing pathway to chronic multisite pain. Finally, multimodal structural brain imaging analysis showed that DCC is most strongly expressed in subcortical limbic regions and is associated with alterations in the uncinate fasciculus microstructure, suggesting that DCC-dependent axonogenesis may contribute to COPC via cortico-limbic circuits.
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Affiliation(s)
- Samar Khoury
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.,Faculty of Dentistry, McGill University, Montreal, QC, Canada.,Department of Anesthesia, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Marc Parisien
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.,Faculty of Dentistry, McGill University, Montreal, QC, Canada.,Department of Anesthesia, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Scott J Thompson
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.,Department of Anesthesiology, University of Minnesota, Minneapolis, MN, USA
| | - Etienne Vachon-Presseau
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.,Faculty of Dentistry, McGill University, Montreal, QC, Canada.,Department of Anesthesia, Faculty of Medicine, McGill University, Montreal, QC, Canada
| | - Mathieu Roy
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.,Department of Psychology, McGill University, Montreal, QC, Canada
| | - Amy E Martinsen
- K. G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Research, Innovation and Education, Division of Clinical Neuroscience, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Bendik S Winsvold
- K. G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Research, Innovation and Education, Division of Clinical Neuroscience, Oslo University Hospital, Oslo, Norway.,Department of Neurology, Oslo University Hospital, Oslo, Norway
| | | | - Ingunn P Mundal
- Department of Health Science, Molde University College, Molde, Norway
| | - John-Anker Zwart
- K. G. Jebsen Center for Genetic Epidemiology, Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Department of Research, Innovation and Education, Division of Clinical Neuroscience, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Artur Kania
- Institut de recherches cliniques de Montreal (IRCM), Montreal, QC, Canada.,Department of Cell Biology and Anatomy, and Experimental Medicine, McGill University, Montreal, QC, Canada
| | - Jeffrey S Mogil
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.,Department of Psychology, McGill University, Montreal, QC, Canada
| | - Luda Diatchenko
- Alan Edwards Centre for Research on Pain, McGill University, Montreal, QC, Canada.,Faculty of Dentistry, McGill University, Montreal, QC, Canada.,Department of Anesthesia, Faculty of Medicine, McGill University, Montreal, QC, Canada
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