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Qin L, Xiao L, Zhu H, Du Y, Tang Y, Feng L. Translocator protein (18 kDa) positron emission tomography imaging as a biomarker of neuroinflammation in epilepsy. Neurol Sci 2024; 45:5201-5211. [PMID: 38879831 DOI: 10.1007/s10072-024-07648-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 06/11/2024] [Indexed: 10/13/2024]
Abstract
Increasing evidence indicate that neuroinflammation triggered by glial cells plays a significant role in epileptogenesis. To this effect, the overexpression of translocator protein 18 kDa (TSPO) in activated microglia and astrocytes has been identified as an inflammatory biomarker in epilepsy. It is now possible to quantify neuroinflammation using non-invasive positron emission tomography (PET) imaging of TSPO. With the advancement of radiotracers, TSPO PET has become an innovative tool in elucidating the "neuroinflammatory machinery" of drug-resistant epilepsy. Furthermore, TSPO PET has demonstrated potential in detecting MRI-negative epileptogenic zones (EZ) and provided an innovative perspective in epileptic medical treatment. This manuscript presents a comprehensive exploration of the neuroinflammatory mechanisms of epilepsy, alongside a thorough review of TSPO PET studies conducted in clinical and preclinical settings. The primary objective is to deepen our understanding of epilepsy progression and to establish TSPO PET as an effective monitoring tool for treatment efficacy.
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Affiliation(s)
- Li Qin
- Department of Neurology, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Ling Xiao
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Haoyue Zhu
- Department of Neurology, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Yangsa Du
- Department of Neurology, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Yongxiang Tang
- Department of Nuclear Medicine, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
| | - Li Feng
- Department of Neurology, National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- Department of Neurology, Xiangya Hospital, Central South University (Jiangxi Branch), Nanchang, 330000, Jiangxi, China.
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VanElzakker MB, Bues HF, Brusaferri L, Kim M, Saadi D, Ratai EM, Dougherty DD, Loggia ML. Neuroinflammation in post-acute sequelae of COVID-19 (PASC) as assessed by [ 11C]PBR28 PET correlates with vascular disease measures. Brain Behav Immun 2024; 119:713-723. [PMID: 38642615 PMCID: PMC11225883 DOI: 10.1016/j.bbi.2024.04.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 02/28/2024] [Accepted: 04/16/2024] [Indexed: 04/22/2024] Open
Abstract
The COVID-19 pandemic caused by SARS-CoV-2 has triggered a consequential public health crisis of post-acute sequelae of COVID-19 (PASC), sometimes referred to as long COVID. The mechanisms of the heterogeneous persistent symptoms and signs that comprise PASC are under investigation, and several studies have pointed to the central nervous and vascular systems as being potential sites of dysfunction. In the current study, we recruited individuals with PASC with diverse symptoms, and examined the relationship between neuroinflammation and circulating markers of vascular dysfunction. We used [11C]PBR28 PET neuroimaging, a marker of neuroinflammation, to compare 12 PASC individuals versus 43 normative healthy controls. We found significantly increased neuroinflammation in PASC versus controls across a wide swath of brain regions including midcingulate and anterior cingulate cortex, corpus callosum, thalamus, basal ganglia, and at the boundaries of ventricles. We also collected and analyzed peripheral blood plasma from the PASC individuals and found significant positive correlations between neuroinflammation and several circulating analytes related to vascular dysfunction. These results suggest that an interaction between neuroinflammation and vascular health may contribute to common symptoms of PASC.
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Affiliation(s)
- Michael B VanElzakker
- Division of Neurotherapeutics, Department of Psychiatry, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; PolyBio Research Foundation, Medford, MA, USA.
| | - Hannah F Bues
- Division of Neurotherapeutics, Department of Psychiatry, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ludovica Brusaferri
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Computer Science And Informatics, School of Engineering, London South Bank University, London, UK
| | - Minhae Kim
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Deena Saadi
- Division of Neurotherapeutics, Department of Psychiatry, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Eva-Maria Ratai
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Darin D Dougherty
- Division of Neurotherapeutics, Department of Psychiatry, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Marco L Loggia
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA; Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
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3
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Traub-Weidinger T, Arbizu J, Barthel H, Boellaard R, Borgwardt L, Brendel M, Cecchin D, Chassoux F, Fraioli F, Garibotto V, Guedj E, Hammers A, Law I, Morbelli S, Tolboom N, Van Weehaeghe D, Verger A, Van Paesschen W, von Oertzen TJ, Zucchetta P, Semah F. EANM practice guidelines for an appropriate use of PET and SPECT for patients with epilepsy. Eur J Nucl Med Mol Imaging 2024; 51:1891-1908. [PMID: 38393374 PMCID: PMC11139752 DOI: 10.1007/s00259-024-06656-3] [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: 11/01/2023] [Accepted: 02/13/2024] [Indexed: 02/25/2024]
Abstract
Epilepsy is one of the most frequent neurological conditions with an estimated prevalence of more than 50 million people worldwide and an annual incidence of two million. Although pharmacotherapy with anti-seizure medication (ASM) is the treatment of choice, ~30% of patients with epilepsy do not respond to ASM and become drug resistant. Focal epilepsy is the most frequent form of epilepsy. In patients with drug-resistant focal epilepsy, epilepsy surgery is a treatment option depending on the localisation of the seizure focus for seizure relief or seizure freedom with consecutive improvement in quality of life. Beside examinations such as scalp video/electroencephalography (EEG) telemetry, structural, and functional magnetic resonance imaging (MRI), which are primary standard tools for the diagnostic work-up and therapy management of epilepsy patients, molecular neuroimaging using different radiopharmaceuticals with single-photon emission computed tomography (SPECT) and positron emission tomography (PET) influences and impacts on therapy decisions. To date, there are no literature-based praxis recommendations for the use of Nuclear Medicine (NM) imaging procedures in epilepsy. The aims of these guidelines are to assist in understanding the role and challenges of radiotracer imaging for epilepsy; to provide practical information for performing different molecular imaging procedures for epilepsy; and to provide an algorithm for selecting the most appropriate imaging procedures in specific clinical situations based on current literature. These guidelines are written and authorized by the European Association of Nuclear Medicine (EANM) to promote optimal epilepsy imaging, especially in the presurgical setting in children, adolescents, and adults with focal epilepsy. They will assist NM healthcare professionals and also specialists such as Neurologists, Neurophysiologists, Neurosurgeons, Psychiatrists, Psychologists, and others involved in epilepsy management in the detection and interpretation of epileptic seizure onset zone (SOZ) for further treatment decision. The information provided should be applied according to local laws and regulations as well as the availability of various radiopharmaceuticals and imaging modalities.
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Affiliation(s)
- Tatjana Traub-Weidinger
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Javier Arbizu
- Department of Nuclear Medicine, University of Navarra Clinic, Pamplona, Spain
| | - Henryk Barthel
- Department of Nuclear Medicine, Leipzig University Medical Centre, Leipzig, Germany
| | - Ronald Boellaard
- Department of Radiology and Nuclear Medicine, Amsterdam UMC, Location VUmc, Amsterdam, The Netherlands
| | - Lise Borgwardt
- Department of Clinical Physiology and Nuclear Medicine, University of Copenhagen, Blegdamsvej 9, DK-2100, RigshospitaletCopenhagen, Denmark
| | - Matthias Brendel
- Department of Nuclear Medicine, Ludwig Maximilian-University of Munich, Munich, Germany
- DZNE-German Center for Neurodegenerative Diseases, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Diego Cecchin
- Nuclear Medicine Unit, Department of Medicine-DIMED, University-Hospital of Padova, Padova, Italy
| | - Francine Chassoux
- Université Paris-Saclay, CEA, CNRS, Inserm, BioMaps, 91401, Orsay, France
| | - Francesco Fraioli
- Institute of Nuclear Medicine, University College London (UCL), London, UK
| | - Valentina Garibotto
- Division of Nuclear Medicine and Molecular Imaging, Geneva University Hospitals, Geneva, Switzerland
- NIMTLab, Faculty of Medicine, University of Geneva, Geneva, Switzerland
- Center for Biomedical Imaging (CIBM), Geneva, Switzerland
| | - Eric Guedj
- APHM, CNRS, Centrale Marseille, Institut Fresnel, Timone Hospital, CERIMED, Nuclear Medicine Department, Aix Marseille Univ, Marseille, France
| | - Alexander Hammers
- School of Biomedical Engineering and Imaging Sciences, Faculty of Life Sciences and Medicine, King's College London & Guy's and St Thomas' PET Centre, King's College London, London, UK
| | - Ian Law
- Department of Clinical Physiology and Nuclear Medicine, Rigshospitalet, University of Copenhagen, Blegdamsvej 9, DK-2100, Copenhagen, Denmark
| | - Silvia Morbelli
- Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy
| | - Nelleke Tolboom
- Department of Radiology and Nuclear Medicine, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | - Antoine Verger
- Department of Nuclear Medicine and Nancyclotep Imaging Platform, CHRU Nancy, Université de Lorraine, IADI, INSERM U1254, Nancy, France
| | - Wim Van Paesschen
- Laboratory for Epilepsy Research, KU Leuven and Department of Neurology, University Hospitals, Leuven, Belgium
| | - Tim J von Oertzen
- Depts of Neurology 1&2, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Pietro Zucchetta
- Nuclear Medicine Unit, Department of Medicine-DIMED, University-Hospital of Padova, Padova, Italy
| | - Franck Semah
- Nuclear Medicine Department, University Hospital, Inserm, CHU Lille, U1172-LilNCog-Lille, F-59000, Lille, France.
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Zhou C, Satpute V, Yip KL, Anderson LL, Hawkins N, Kearney J, Arnold JC. A high seizure burden increases several prostaglandin species in the hippocampus of a Scn1a +/- mouse model of Dravet syndrome. Prostaglandins Other Lipid Mediat 2024; 172:106836. [PMID: 38599513 DOI: 10.1016/j.prostaglandins.2024.106836] [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: 01/09/2024] [Revised: 04/02/2024] [Accepted: 04/05/2024] [Indexed: 04/12/2024]
Abstract
Dravet syndrome is an intractable epilepsy with a high seizure burden that is resistant to current anti-seizure medications. There is evidence that neuroinflammation plays a role in epilepsy and seizures, however few studies have specifically examined neuroinflammation in Dravet syndrome under conditions of a higher seizure burden. Here we used an established genetic mouse model of Dravet syndrome (Scn1a+/- mice), to examine whether a higher seizure burden impacts the number and morphology of microglia in the hippocampus. Moreover, we examined whether a high seizure burden influences classical inflammatory mediators in this brain region. Scn1a+/- mice with a high seizure burden induced by thermal priming displayed a localised reduction in microglial cell density in the granule cell layer and subgranular zone of the dentate gyrus, regions important to postnatal neurogenesis. However, microglial cell number and morphology remained unchanged in other hippocampal subfields. The high seizure burden in Scn1a+/- mice did not affect hippocampal mRNA expression of classical inflammatory mediators such as interleukin 1β and tumour necrosis factor α, but increased cyclooxygenase 2 (COX-2) expression. We then quantified hippocampal levels of prostanoids that arise from COX-2 mediated metabolism of fatty acids and found that Scn1a+/- mice with a high seizure burden displayed increased hippocampal concentrations of numerous prostaglandins, notably PGF2α, PGE2, PGD2, and 6-K-PGF1A, compared to Scn1a+/- mice with a low seizure burden. In conclusion, a high seizure burden increased hippocampal concentrations of various prostaglandin mediators in a mouse model of Dravet syndrome. Future studies could interrogate the prostaglandin pathways to further better understand their role in the pathophysiology of Dravet syndrome.
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Affiliation(s)
- Cilla Zhou
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia; Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Vaishali Satpute
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Ka Lai Yip
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Lyndsey L Anderson
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia
| | - Nicole Hawkins
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jennifer Kearney
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, IL 60611, USA
| | - Jonathon C Arnold
- Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, Sydney, NSW 2050, Australia; Discipline of Pharmacology, School of Pharmacy, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia; Brain and Mind Centre, The University of Sydney, Sydney, NSW 2050, Australia.
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5
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Cheval M, Rodrigo S, Taussig D, Caillé F, Petrescu AM, Bottlaender M, Tournier N, Besson FL, Leroy C, Bouilleret V. [ 18F]DPA-714 PET Imaging in the Presurgical Evaluation of Patients With Drug-Resistant Focal Epilepsy. Neurology 2023; 101:e1893-e1904. [PMID: 37748889 PMCID: PMC10663012 DOI: 10.1212/wnl.0000000000207811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 07/17/2023] [Indexed: 09/27/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Translocator protein 18 kDa (TSPO) PET imaging is used to monitor glial activation. Recent studies have proposed TSPO PET as a marker of the epileptogenic zone (EZ) in drug-resistant focal epilepsy (DRFE). This study aims to assess the contributions of TSPO imaging using [18F]DPA-714 PET and [18F]FDG PET for localizing the EZ during presurgical assessment of DRFE, when phase 1 presurgical assessment does not provide enough information. METHODS We compared [18F]FDG and [18F]DPA-714 PET images of 23 patients who had undergone a phase 1 presurgical assessment, using qualitative visual analysis and quantitative analysis, at both the voxel and the regional levels. PET abnormalities (increase in binding for [18F]DPA-714 vs decrease in binding for [18F]FDG) were compared with clinical hypotheses concerning the localization of the EZ based on phase 1 presurgical assessment. The additional value of [18F]DPA-714 PET imaging to [18F]FDG for refining the localization of the EZ was assessed. To strengthen the visual analysis, [18F]DPA-714 PET imaging was also reviewed by 2 experienced clinicians blind to the EZ location. RESULTS The study included 23 patients. Visual analysis of [18F]DPA-714 PET was significantly more accurate than [18F]FDG PET to both, show anomalies (95.7% vs 56.5%, p = 0.022), and provide additional information to refine the EZ localization (65.2% vs 17.4%, p = 0.019). All 10 patients with normal [18F]FDG PET had anomalies when using [18F]DPA-714 PET. The additional value of [18F]DPA-714 PET seemed to be greater in patients with normal brain MRI or with neocortical EZ (especially if insula is involved). Regional analysis of [18F]DPA-714 and [18F]FDG PET provided similar results. However, using voxel-wise analysis, [18F]DPA-714 was more effective than [18F]FDG for unveiling clusters whose localization was more often consistent with the EZ hypothesis (87.0% vs 39.1%, p = 0.019). Nonrelevant bindings were seen in 14 of 23 patients in visual analysis and 9 patients of 23 patients in voxel-wise analysis. DISCUSSION [18F]DPA-714 PET imaging provides valuable information for presurgical assessments of patients with DRFE. TSPO PET could become an additional tool to help to the localization of the EZ, especially in patients with negative [18F]FDG PET. TRIAL REGISTRATION INFORMATION Eudract 2017-003381-27. Inclusion of the first patient: September 24, 2018. CLASSIFICATION OF EVIDENCE This study provides Class IV evidence on the utility of [18F]DPA-714 PET compared with [18F]FDG PET in identifying the epileptic zone in patients undergoing phase 1 presurgical evaluation for intractable epilepsy.
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Affiliation(s)
- Margaux Cheval
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France.
| | - Sebastian Rodrigo
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Delphine Taussig
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Fabien Caillé
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Ana Maria Petrescu
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Michel Bottlaender
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Nicolas Tournier
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Florent L Besson
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Claire Leroy
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
| | - Viviane Bouilleret
- From the Université Paris-Saclay (M.C., C.L., M.B., N.T.); BioMAPS (S.R., F.C., F.L.B.); Bicetre University Hospital (D.T., A.M.P.), Paris; and Imagerie Moléculaire In Vivo (V.B.), SHFJ, CEA, Orsay, France
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Yu C, Deng XJ, Xu D. Microglia in epilepsy. Neurobiol Dis 2023; 185:106249. [PMID: 37536386 DOI: 10.1016/j.nbd.2023.106249] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 07/07/2023] [Accepted: 07/31/2023] [Indexed: 08/05/2023] Open
Abstract
Epilepsy is one of most common chronic neurological disorders, and the antiseizure medications developed by targeting neurocentric mechanisms have not effectively reduced the proportion of patients with drug-resistant epilepsy. Further exploration of the cellular or molecular mechanism of epilepsy is expected to provide new options for treatment. Recently, more and more researches focus on brain network components other than neurons, among which microglia have attracted much attention for their diverse biological functions. As the resident immune cells of the central nervous system, microglia have highly plastic transcription, morphology and functional characteristics, which can change dynamically in a context-dependent manner during the progression of epilepsy. In the pathogenesis of epilepsy, highly reactive microglia interact with other components in the epileptogenic network by performing crucial functions such as secretion of soluble factors and phagocytosis, thus continuously reshaping the landscape of the epileptic brain microenvironment. Indeed, microglia appear to be both pro-epileptic and anti-epileptic under the different spatiotemporal contexts of disease, rendering interventions targeting microglia biologically complex and challenging. This comprehensive review critically summarizes the pathophysiological role of microglia in epileptic brain homeostasis alterations and explores potential therapeutic or modulatory targets for epilepsy targeting microglia.
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Affiliation(s)
- Cheng Yu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei Province 430022, China
| | - Xue-Jun Deng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei Province 430022, China
| | - Da Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, Hubei Province 430022, China.
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7
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Sukprakun C, Tepmongkol S. Nuclear imaging for localization and surgical outcome prediction in epilepsy: A review of latest discoveries and future perspectives. Front Neurol 2022; 13:1083775. [PMID: 36588897 PMCID: PMC9800996 DOI: 10.3389/fneur.2022.1083775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
Background Epilepsy is one of the most common neurological disorders. Approximately, one-third of patients with epilepsy have seizures refractory to antiepileptic drugs and further require surgical removal of the epileptogenic region. In the last decade, there have been many recent developments in radiopharmaceuticals, novel image analysis techniques, and new software for an epileptogenic zone (EZ) localization. Objectives Recently, we provided the latest discoveries, current challenges, and future perspectives in the field of positron emission tomography (PET) and single-photon emission computed tomography (SPECT) in epilepsy. Methods We searched for relevant articles published in MEDLINE and CENTRAL from July 2012 to July 2022. A systematic literature review based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis was conducted using the keywords "Epilepsy" and "PET or SPECT." We included both prospective and retrospective studies. Studies with preclinical subjects or not focusing on EZ localization or surgical outcome prediction using recently developed PET radiopharmaceuticals, novel image analysis techniques, and new software were excluded from the review. The remaining 162 articles were reviewed. Results We first present recent findings and developments in PET radiopharmaceuticals. Second, we present novel image analysis techniques and new software in the last decade for EZ localization. Finally, we summarize the overall findings and discuss future perspectives in the field of PET and SPECT in epilepsy. Conclusion Combining new radiopharmaceutical development, new indications, new techniques, and software improves EZ localization and provides a better understanding of epilepsy. These have proven not to only predict prognosis but also to improve the outcome of epilepsy surgery.
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Affiliation(s)
- Chanan Sukprakun
- Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Supatporn Tepmongkol
- Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand,Chulalongkorn University Biomedical Imaging Group (CUBIG), Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand,Chula Neuroscience Center, King Chulalongkorn Memorial Hospital, Bangkok, Thailand,Cognitive Impairment and Dementia Research Unit, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand,*Correspondence: Supatporn Tepmongkol ✉
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8
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Kagitani-Shimono K, Kato H, Soeda F, Iwatani Y, Mukai M, Ogawa K, Tominaga K, Nabatame S, Taniike M. Extension of microglial activation is associated with epilepsy and cognitive dysfunction in Tuberous sclerosis complex: A TSPO-PET study. Neuroimage Clin 2022; 37:103288. [PMID: 36521371 PMCID: PMC9758490 DOI: 10.1016/j.nicl.2022.103288] [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: 09/17/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND AND OBJECTIVES Neuroinflammation contributes to the severity of various neurological disorders, including epilepsy. Tuberous sclerosis complex (TSC) is a condition that results in the overactivation of the mammalian target of rapamycin (mTOR) pathway, which has been linked to the activation of microglia responsible for neuroinflammation. To clarify the involvement of neuroinflammation in the neuropathophysiology of TSC, we performed a positron emission tomography (PET) study using the translocator protein (TSPO) radioligand, [11C] DPA713, and investigated microglial activation in relation to neurological manifestations, especially epilepsy and cognitive function. METHODS This cross-sectional study included 18 patients with TSC (6 in the no-seizure group, 6 in the refractory seizure group, and 6 in the mTOR-inhibitor [mTOR-i] group). All participants underwent [11C] DPA713-PET. PET results were superimposed with a 3D T2-weighted fluid-attenuated inversion-recovery (FLAIR) and T1-weighted image (T1WI) to evaluate the location of cortical tubers. Microglial activation was assessed using the standardized uptake value ratio (SUVr) of DPA713 binding. The volume ratio of the DPA713-positive area to the intracranial volume (volume ratio of DPA713/ICV) was calculated to evaluate the extent of microglial activation. A correlation analysis was performed to examine the relationship between volume ratio of DPA713/ICV and severity of epilepsy and cognitive function. RESULTS Most cortical tubers with hyperintensity on FLAIR and hypo- or isointensity on T1WI showed microglial activation. The extent of microglial activation was significantly greater in the refractory seizure group than in the no-seizure or mTOR-i groups (p < 0.001). The extent of microglial activation in subjects without mTOR-i treatment correlated positively with epilepsy severity (r = 0.822, P = 0.001) and negatively with cognitive function (r = -0.846, p = 0.001), but these correlations were not present in the mTOR-i group (r = 0.232, P = 0.658, r = 0.371, P = 0.469, respectively). CONCLUSION Neuroinflammation is associated with the severity of epilepsy and cognitive dysfunction in brains with TSC. mTOR-i may suppress the extent of neuroinflammation in TSC. Investigating the spread of microglial activation using TSPO-PET in these patients may help to predict the progression of neuropathy by assessing the degree of neuroinflammation and therefore be useful for determining how aggressive the treatment should be and in assessing the effectiveness of such treatment in patients with TSC.
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Affiliation(s)
- Kuriko Kagitani-Shimono
- Department of Child Development, United Graduate School of Child Development, Osaka University, Osaka, Japan; Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan.
| | - Hiroki Kato
- Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Fumihiko Soeda
- Department of Nuclear Medicine and Tracer Kinetics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Yoshiko Iwatani
- Department of Child Development, United Graduate School of Child Development, Osaka University, Osaka, Japan; Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Masashi Mukai
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Katsuhiro Ogawa
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Koji Tominaga
- Department of Child Development, United Graduate School of Child Development, Osaka University, Osaka, Japan; Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Shin Nabatame
- Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
| | - Masako Taniike
- Department of Child Development, United Graduate School of Child Development, Osaka University, Osaka, Japan; Department of Pediatrics, Osaka University Graduate School of Medicine, Osaka, Japan
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Cheval M, Rodrigo S, Petrescu AM, Leroy C, Bouilleret V. [18F]DPA-714 PET imaging: a new tool to reveal the hidden part of focal drug-resistant epilepsy? Acta Neurol Belg 2022; 123:757-759. [PMID: 36083422 DOI: 10.1007/s13760-022-02079-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 08/24/2022] [Indexed: 11/01/2022]
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Kinetic modeling and non-invasive approach for translocator protein quantification with 11C-DPA-713. Nucl Med Biol 2022; 108-109:76-84. [DOI: 10.1016/j.nucmedbio.2022.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Revised: 02/22/2022] [Accepted: 02/28/2022] [Indexed: 11/20/2022]
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Bouilleret V, Dedeurwaerdere S. What value can TSPO PET bring for epilepsy treatment? Eur J Nucl Med Mol Imaging 2021; 49:221-233. [PMID: 34120191 DOI: 10.1007/s00259-021-05449-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/03/2021] [Indexed: 12/13/2022]
Abstract
Epilepsy is one of the most common neurological disorders and affects both the young and adult populations. The question we asked for this review was how positron emission tomography (PET) imaging with translocator protein (TSPO) radioligands can help inform the epilepsy clinic and the development of future treatments targeting neuroinflammatory processes.Even though the first TSPO PET scans in epilepsy patients were performed over 20 years ago, this imaging modality has not seen wide adoption in the clinic. There is vast scientific evidence from preclinical studies in rodent models of temporal lobe epilepsy which have shown increased levels of TSPO corresponding to neuroinflammatory processes in the brain. These increases peaked sub-acutely (1-2 weeks) after the epileptogenic insult (e.g. status epilepticus) and remained chronically increased, albeit at lower levels. In addition, these studies have shown a correlation between TSPO levels and seizure outcome, pharmacoresistance and behavioural morbidities. Histological assessment points to a complex interplay between different cellular components such as microglial activation, astrogliosis and cell death changing dynamically over time.In epilepsy patients, a highly sensitive biomarker of neuroinflammation would provide value for the optimization of surgical assessment (particularly for extratemporal lobe epilepsy) and support the clinical development path of anti-inflammatory treatments. Clinical studies have shown a systematic increase in asymmetry indices of TSPO PET binding. However, region-based analysis typically does not yield statistical differences and changes are often not restricted to the epileptogenic zone, limiting the ability of this imaging modality to localise pathology for surgery. In this manuscript, we discuss the biological underpinnings of these findings and review for which applications in epilepsy TSPO PET could bring added value.
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Affiliation(s)
- Viviane Bouilleret
- Unité de Neurophysiologie et d'Epileptologie (UNCE), Université Paris-Saclay APHP, 78, Rue du Général Leclerc, 94275, Le Kremlin Bicêtre, France.
- CEA, CNRS, Inserm, BioMaps, Université Paris-Saclay, Orsay, France.
| | - Stefanie Dedeurwaerdere
- Neurosciences Therapeutic Area, Early Solutions, UCB Pharma, Braine-l'Alleud, Belgium
- Experimental Laboratory of Haematology, University of Antwerp, Wilrijk, Belgium
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Zaitsev АV, Amakhin DV, Dyomina AV, Zakharova MV, Ergina JL, Postnikova TY, Diespirov GP, Magazanik LG. Synaptic Dysfunction in Epilepsy. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s002209302103008x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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The role of inflammatory mediators in epilepsy: Focus on developmental and epileptic encephalopathies and therapeutic implications. Epilepsy Res 2021; 172:106588. [PMID: 33721708 DOI: 10.1016/j.eplepsyres.2021.106588] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 02/06/2023]
Abstract
In recent years, there has been an increasing interest in the potential involvement of neuroinflammation in the pathogenesis of epilepsy. Specifically, the role of innate immunity (that includes cytokines and chemokines) has been extensively investigated either in animal models of epilepsy and in clinical settings. Developmental and epileptic encephalopathies (DEE) are a heterogeneous group of epileptic disorders, in which uncontrolled epileptic activity results in cognitive, motor and behavioral impairment. By definition, epilepsy in DEE is poorly controlled by common antiepileptic drugs but may respond to alternative treatments, including steroids and immunomodulatory drugs. In this review, we will focus on how cytokines and chemokines play a role in the pathogenesis of DEE and why expanding our knowledge about the role of neuroinflammation in DEE may be crucial to develop new and effective targeted therapeutic strategies to prevent seizure recurrence and developmental regression.
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