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Hobson BA, Rowland DJ, Dou Y, Saito N, Harmany ZT, Bruun DA, Harvey DJ, Chaudhari AJ, Garbow JR, Lein PJ. A longitudinal MRI and TSPO PET-based investigation of brain region-specific neuroprotection by diazepam versus midazolam following organophosphate-induced seizures. Neuropharmacology 2024; 251:109918. [PMID: 38527652 DOI: 10.1016/j.neuropharm.2024.109918] [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: 11/29/2023] [Revised: 03/01/2024] [Accepted: 03/13/2024] [Indexed: 03/27/2024]
Abstract
Acute poisoning with organophosphorus cholinesterase inhibitors (OPs), such as OP nerve agents and pesticides, can cause life threatening cholinergic crisis and status epilepticus (SE). Survivors often experience significant morbidity, including brain injury, acquired epilepsy, and cognitive deficits. Current medical countermeasures for acute OP poisoning include a benzodiazepine to mitigate seizures. Diazepam was long the benzodiazepine included in autoinjectors used to treat OP-induced seizures, but it is now being replaced in many guidelines by midazolam, which terminates seizures more quickly, particularly when administered intramuscularly. While a direct correlation between seizure duration and the extent of brain injury has been widely reported, there are limited data comparing the neuroprotective efficacy of diazepam versus midazolam following acute OP intoxication. To address this data gap, we used non-invasive imaging techniques to longitudinally quantify neuropathology in a rat model of acute intoxication with the OP diisopropylfluorophosphate (DFP) with and without post-exposure intervention with diazepam or midazolam. Magnetic resonance imaging (MRI) was used to monitor neuropathology and brain atrophy, while positron emission tomography (PET) with a radiotracer targeting translocator protein (TSPO) was utilized to assess neuroinflammation. Animals were scanned at 3, 7, 28, 65, 91, and 168 days post-DFP and imaging metrics were quantitated for the hippocampus, amygdala, piriform cortex, thalamus, cerebral cortex and lateral ventricles. In the DFP-intoxicated rat, neuroinflammation persisted for the duration of the study coincident with progressive atrophy and ongoing tissue remodeling. Benzodiazepines attenuated neuropathology in a region-dependent manner, but neither benzodiazepine was effective in attenuating long-term neuroinflammation as detected by TSPO PET. Diffusion MRI and TSPO PET metrics were highly correlated with seizure severity, and early MRI and PET metrics were positively correlated with long-term brain atrophy. Collectively, these results suggest that anti-seizure therapy alone is insufficient to prevent long-lasting neuroinflammation and tissue remodeling.
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Affiliation(s)
- Brad A Hobson
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA; Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA 95616, USA.
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA 95616, USA.
| | - Yimeng Dou
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
| | - Naomi Saito
- Department of Public Health Sciences, University of California, Davis, School of Medicine, California 95616, USA.
| | - Zachary T Harmany
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA 95616, USA.
| | - Donald A Bruun
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
| | - Danielle J Harvey
- Department of Public Health Sciences, University of California, Davis, School of Medicine, California 95616, USA.
| | - Abhijit J Chaudhari
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA 95616, USA; Department of Radiology, University of California, Davis, School of Medicine, California 95817, USA.
| | - Joel R Garbow
- Biomedical Magnetic Resonance Center, Mallinckrodt Institute of Radiology, School of Medicine, Washington University in St. Louis, St. Louis, Missouri, 63110, USA.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA 95616, USA.
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Tsytsarev V, Sopova JV, Leonova EI, Inyushin M, Markina AA, Chirinskaite AV, Volnova AB. Neurophotonic methods in approach to in vivo animal epileptic models: Advantages and limitations. Epilepsia 2024; 65:600-614. [PMID: 38115808 PMCID: PMC10948300 DOI: 10.1111/epi.17870] [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: 07/18/2023] [Revised: 12/16/2023] [Accepted: 12/18/2023] [Indexed: 12/21/2023]
Abstract
Neurophotonic technology is a rapidly growing group of techniques that are based on the interactions of light with natural or genetically modified cells of the neural system. New optical technologies make it possible to considerably extend the tools of neurophysiological research, from the visualization of functional activity changes to control of brain tissue excitability. This opens new perspectives for studying the mechanisms underlying the development of human neurological diseases. Epilepsy is one of the most common brain disorders; it is characterized by recurrent seizures and affects >1% of the world's population. However, how seizures occur, spread, and terminate in a healthy brain is still unclear. Therefore, it is extremely important to develop appropriate models to accurately explore the causal relationship of epileptic activity. The use of neurophotonic technologies in epilepsy research falls into two broad categories: the visualization of neural epileptic activity, and the direct optical influence on neurons to induce or suppress epileptic activity. An optogenetic variant of the classical kindling model of epileptic seizures, in which activatable cells are genetically defined, is called optokindling. Research is also underway concerning the application of neurophotonic techniques for suppressing epileptic activity, aiming to bring these methods into clinical practice. This review aims to systematize and describe new approaches that use combinations of different neurophotonic methods to work with in vivo models of epilepsy. These approaches overcome many of the shortcomings associated with classical animal models of epilepsy and thus increase the effectiveness of developing new diagnostic methods and antiepileptic therapy.
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Affiliation(s)
- Vassiliy Tsytsarev
- University of Maryland School of Medicine, Department of Neurobiology 20 Penn St, HSF-2, 21201 MD, Baltimore, United States
| | - Julia V. Sopova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Elena I. Leonova
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Mikhail Inyushin
- School of Medicine, Universidad Central del Caribe, Bayamon, PR 00956, USA
| | - Alisa A. Markina
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg 199034, Russia
| | - Angelina V. Chirinskaite
- Center of Transgenesis and Genome Editing, St. Petersburg State University, 199034 St. Petersburg, Russia
| | - Anna B. Volnova
- Institute of Translational Biomedicine, Saint Petersburg State University, St. Petersburg 199034, Russia
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Lungren MP, Wilson DU. Artificial intelligence in veterinary care will be a major driving force behind ai advancements in healthcare. Vet Radiol Ultrasound 2022; 63 Suppl 1:913-915. [PMID: 36514232 DOI: 10.1111/vru.13161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 12/04/2021] [Accepted: 02/08/2022] [Indexed: 12/15/2022] Open
Affiliation(s)
| | - Diane U Wilson
- Antech Imaging Services, Fountain Valley, California, USA
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van Vliet EA, Immonen R, Prager O, Friedman A, Bankstahl JP, Wright DK, O'Brien TJ, Potschka H, Gröhn O, Harris NG. A companion to the preclinical common data elements and case report forms for in vivo rodent neuroimaging: A report of the TASK3-WG3 Neuroimaging Working Group of the ILAE/AES Joint Translational Task Force. Epilepsia Open 2022. [PMID: 35962745 DOI: 10.1002/epi4.12643] [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: 12/12/2021] [Accepted: 02/01/2022] [Indexed: 11/10/2022] Open
Abstract
The International League Against Epilepsy/American Epilepsy Society (ILAE/AES) Joint Translational Task Force established the TASK3 working groups to create common data elements (CDEs) for various aspects of preclinical epilepsy research studies, which could help improve the standardization of experimental designs. In this article, we discuss CDEs for neuroimaging data that are collected in rodent models of epilepsy, with a focus on adult rats and mice. We provide detailed CDE tables and case report forms (CRFs), and with this companion manuscript, we discuss the methodologies for several imaging modalities and the parameters that can be collected.
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Affiliation(s)
- Erwin A van Vliet
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, The Netherlands
- Amsterdam UMC Location University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Riikka Immonen
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Ofer Prager
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Alon Friedman
- Departments of Physiology and Cell Biology, Cognitive and Brain Sciences, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Department of Medical Neuroscience and Brain Repair Center, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - David K Wright
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Terence J O'Brien
- The Royal Melbourne Hospital, The University of Melbourne, The Alfred Hospital, Monash University, Melbourne, Victoria, Australia
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Olli Gröhn
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Neil G Harris
- Department of Neurosurgery UCLA, UCLA Brain Injury Research Center, Los Angeles, California, USA
- Intellectual and Developmental Disabilities Research Center, UCLA, Los Angeles, California, USA
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Jahreis I, Bascuñana P, Ross TL, Bankstahl JP, Bankstahl M. Choice of anesthesia and data analysis method strongly increases sensitivity of 18F-FDG PET imaging during experimental epileptogenesis. PLoS One 2021; 16:e0260482. [PMID: 34818362 PMCID: PMC8612569 DOI: 10.1371/journal.pone.0260482] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 11/09/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose Alterations in brain glucose metabolism detected by 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) positron emission tomography (PET) may serve as an early predictive biomarker and treatment target for epileptogenesis. Here, we aimed to investigate changes in cerebral glucose metabolism before induction of epileptogenesis, during epileptogenesis as well as during chronic epilepsy. As anesthesia is usually unavoidable for preclinical PET imaging and influences the distribution of the radiotracer, four different protocols were compared. Procedures We investigated 18F-FDG uptake phase in conscious rats followed by a static scan as well as dynamic scans under continuous isoflurane, medetomidine-midazolam-fentanyl (MMF), or propofol anesthesia. Furthermore, we applied different analysis approaches: atlas-based regional analysis, statistical parametric mapping, and kinetic analysis. Results At baseline and compared to uptake in conscious rats, isoflurane and propofol anesthesia resulted in decreased cortical 18F-FDG uptake while MMF anesthesia led to a globally decreased tracer uptake. During epileptogenesis, MMF anesthesia was clearly best distinctive for visualization of prominently increased glucometabolism in epilepsy-related brain areas. Kinetic modeling further increased sensitivity, particularly for continuous isoflurane anesthesia. During chronic epilepsy, hypometabolism affecting more or less the whole brain was detectable with all protocols. Conclusion This study reveals evaluation of anesthesia protocols for preclinical 18F-FDG PET imaging as a critical step in the study design. Together with an appropriate data analysis workflow, the chosen anesthesia protocol may uncover otherwise concealed disease-associated regional glucometabolic changes.
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Affiliation(s)
- Ina Jahreis
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Pablo Bascuñana
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Tobias L. Ross
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
| | - Jens P. Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
- * E-mail:
| | - Marion Bankstahl
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
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Balak N. Letter: Deep Brain Stimulation in Epilepsy: A Role for Modulation of the Mammillothalamic Tract in Seizure Control? Neurosurgery 2021; 88:E283-E284. [PMID: 33428768 DOI: 10.1093/neuros/nyaa500] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 09/20/2020] [Indexed: 11/14/2022] Open
Affiliation(s)
- Naci Balak
- Department of Neurosurgery Göztepe Education and Research Hospital Istanbul Medeniyet University Istanbul, Turkey
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Niu N, Xing H, Wu M, Ma Y, Liu Y, Ba J, Zhu S, Li F, Huo L. Performance of PET imaging for the localization of epileptogenic zone in patients with epilepsy: a meta-analysis. Eur Radiol 2021; 31:6353-6366. [PMID: 33523306 DOI: 10.1007/s00330-020-07645-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 12/02/2020] [Accepted: 12/17/2020] [Indexed: 01/31/2023]
Abstract
OBJECTIVES The aim of this meta-analysis was to estimate the clinical use value of 11C-FMZ and 18F-FDG in PET for the localization of epileptogenic zone and to provide evidence for practitioners' clinical decision-making. METHODS We searched PubMed and Embase in a time frame from inception to May 31, 2020. Studies utilizing FMZ or FDG-PET or FDG-PET/MRI used in patients with epilepsy, with EEG or surgical outcomes as the gold standard and corresponding outcomes such as concordance rates of PET or PET/MRI scan compared with reference standard, absolute numbers of participants with true-positive (TP), false-positive (FP), true-negative (TN), and false-negative (FN) results in FDG or FMZ PET. Pooled concordance rates, overall sensitivity, and specificity of 11C-FMZ-PET and 18F-FDG-PET were calculated. RESULTS In total, 44 studies met the inclusion criteria. The pooled concordance rates of FDG-PET, FMZ-PET, and FDG-PET/MRI coregistration compared with reference standard were 0.67 (95% CI: 0.60-0.73), 0.75 (95% CI: 0.57-0.93), and 0.93 (95% CI: 0.89-0.97), respectively. The concordance rate of 18F-FDG-PET in patients with temporal lobe epilepsy (TLE) was 0.79 (0.63; 0.92). The overall sensitivity and specificity of 18F-FDG-PET were 0.66 (95% CI: 0.58-0.73) and 0.71 (95% CI: 0.63-0.78), respectively. 11C-FMZ-PET displayed an overall sensitivity of 0.62 (95% CI: 0.49-0.73) and specificity of 0.73 (95% CI: 0.59-0.84). CONCLUSIONS Both 11C-FMZ PET and 18F-FDG PET are the choice of modalities for the localization of epileptogenic zone, especially when coregistered with MRI. KEY POINTS • 11C-FMZ-PET may be more helpful than 18F-FDG-PET in the localization of epilepsy foci. • Coregistration of FDG-PET and MRI is recommended in the localization of epileptogenic zone.
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Affiliation(s)
- Na Niu
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, 100730, China
| | - Haiqun Xing
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, 100730, China
| | - Meiqi Wu
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, 100730, China
| | - Yanru Ma
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, 100730, China
| | - Yimin Liu
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, 100730, China
| | - Jiantao Ba
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, 100730, China
| | - Shikun Zhu
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, 100730, China
| | - Fang Li
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, 100730, China
| | - Li Huo
- Department of Nuclear Medicine, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, Beijing, 100730, China.
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Serrano ME, Bahri MA, Becker G, Seret A, Germonpré C, Lemaire C, Giacomelli F, Mievis F, Luxen A, Salmon E, Rogister B, Raedt R, Plenevaux A. Exploring with [ 18F]UCB-H the in vivo Variations in SV2A Expression through the Kainic Acid Rat Model of Temporal Lobe Epilepsy. Mol Imaging Biol 2020; 22:1197-1207. [PMID: 32206990 PMCID: PMC7497718 DOI: 10.1007/s11307-020-01488-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
PURPOSE The main purpose of this study was to understand how the positron emission tomography (PET) measure of the synaptic vesicle 2A (SV2A) protein varies in vivo during the development of temporal lobe epilepsy (TLE) in the kainic acid rat model. PROCEDURES Twenty Sprague Dawley male rats were administered with multiple systemic doses of saline (control group, n = 5) or kainic acid (5 mg/kg/injection, epileptic group, n = 15). Both groups were scanned at the four phases of TLE (early, latent, transition, and chronic phase) with the [18F]UCB-H PET radiotracer and T2-structural magnetic resonance imaging. At the end of the scans (3 months post-status epilepticus), rats were monitored for 7 days with electroencephalography for the detection of spontaneous electrographic seizures. Finally, the immunofluorescence staining for SV2A expression was performed. RESULTS Control rats presented a significant increase in [18F]UCB-H binding at the last two scans, compared with the first ones (p < 0.001). This increase existed but was lower in epileptic animals, producing significant group differences in all the phases of the disease (p < 0.028). Furthermore, the quantification of the SV2A expression in vivo with the [18F]UCB-H radiotracer or ex vivo with immunofluorescence led to equivalent results, with a positive correlation between both. CONCLUSIONS Even if further studies in humans are required, the ability to detect a progressive decrease in SV2A expression during the development of temporal lobe epilepsy supports the use of [18F]UCB-H as a useful tool to differentiate, in vivo, between healthy and epileptic animals along with the development of the epileptic disease.
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Affiliation(s)
- Maria Elisa Serrano
- GIGA, CRC in vivo imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium.
- Department of Neuroimaging, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, SE5 9NU, UK.
| | - Mohamed Ali Bahri
- GIGA, CRC in vivo imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Guillaume Becker
- GIGA, CRC in vivo imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
- Radiobiology Unit, SCK•CEN, Belgian Nuclear Research Centre, 2400, Mol, Belgium
| | - Alain Seret
- GIGA, CRC in vivo imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | | | - Christian Lemaire
- GIGA, CRC in vivo imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Fabrice Giacomelli
- Nucleis, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Frédéric Mievis
- Nucleis, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - André Luxen
- GIGA, CRC in vivo imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
| | - Eric Salmon
- GIGA, CRC in vivo imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
- Neurology Department, CHU, Academic Hospital, University of Liège, 4000, Liège, Belgium
| | - Bernard Rogister
- Neurology Department, CHU, Academic Hospital, University of Liège, 4000, Liège, Belgium
- GIGA-Neurosciences, University of Liège, Avenue Hippocrate, 15, 4000, Liège, Belgium
| | | | - Alain Plenevaux
- GIGA, CRC in vivo imaging, University of Liège, Allée du 6 Août, Building B30, Sart Tilman, 4000, Liège, Belgium
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Gelfuso EA, Reis SL, Pereira AMS, Aguiar DSR, Beleboni RO. Neuroprotective effects and improvement of learning and memory elicited by erythravine and 11α-hydroxy-erythravine against the pilocarpine model of epilepsy. Life Sci 2020; 240:117072. [PMID: 31751584 DOI: 10.1016/j.lfs.2019.117072] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 12/19/2022]
Abstract
Deficits in cognitive functions are often observed in epileptic patients, particularly in temporal lobe epilepsy (TLE). Evidence suggests that this cognitive decline can be associated with the occurrence of focal brain lesions, especially on hippocampus and cortex regions. We previously demonstrated that the erythrinian alkaloids, (+)-erythravine and (+)-11α-hydroxy-erythravine, inhibit seizures evoked in rats by different chemoconvulsants. AIMS The current study evaluated if these alkaloids would be acting in a neuroprotective way, reducing hippocampal sclerosis, and consequently, improving learning/memory performance. MAIN METHODS Here we confirmed the anticonvulsant effect of both alkaloids by means of the pilocarpine seizure-induced model and also showed that they enhanced spatial learning of rats submitted to the Morris Water Maze test reverting the cognition deficit. Additionally, immunohistochemistry assays showed that neuronal death and glial activation were prevented by the alkaloids in the hippocampus CA1, CA3 and dentate gyrus regions at both hemispheres indistinctly 15 days after status epilepticus induction. KEY FINDINGS Our results show, for the first-time, the improvement on memory/learning elicited by these erythrinian alkaloids. Furthermore, data presented herein explain, at least partially, the cellular mechanism of action of these alkaloids. Together, (+)-erythravine and (+)-11α-hydroxy-erythravine seem to be a promising protective strategy against TLE, comprising three main aspects: neuroprotection, control of epileptic seizures and cognitive improvement. SIGNIFICANCE Moreover, our findings on neuroprotection corroborate the view that seizure frequency and severity, hippocampal lesions and memory deficits are interconnected events.
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Affiliation(s)
- Erica Aparecida Gelfuso
- Department of Biotechnology, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil
| | - Suelen Lorenzato Reis
- Department of Biotechnology, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil
| | | | | | - Renê Oliveira Beleboni
- Department of Biotechnology, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil; School of Medicine, University of Ribeirão Preto, Ribeirão Preto, São Paulo, Brazil.
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In vivo measurement of brain network connectivity reflects progression and intrinsic disease severity in a model of temporal lobe epilepsy. Neurobiol Dis 2019; 127:45-52. [PMID: 30798008 DOI: 10.1016/j.nbd.2019.02.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 01/30/2019] [Accepted: 02/20/2019] [Indexed: 12/23/2022] Open
Abstract
Different types of brain injury, such as status epilepticus (SE), trauma, or stroke may initiate the process of epileptogenesis and lead to the development of temporal lobe epilepsy. Epileptogenesis is characterized by an initial latent period during which impaired network communication and synaptic circuit alterations are occurring. Ultimately, these modifications result in the development of spontaneous recurrent seizures (SRS). Current knowledge on the functional connectivity network changes during epileptogenesis and how network alterations relate to seizure is very limited. To investigate these underlying network connectivity modifications, we imaged epileptic and control rats by means of resting-state functional MRI (rsfMRI) during epileptogenesis. A cohort of animals was video-electroencephalography (video-EEG) monitored continuously over 12 weeks to determine disease severity during the course of disease, with the first SRS appearing around 2 weeks post-SE for most of the animals. Epileptic animals displayed a significant wide-spread hyposynchrony at 2 weeks post-SE, followed by a significant increase in network synchronicity from 2 to 4 weeks post-SE. Interestingly, subjects with a delayed epilepsy onset demonstrated significantly lower synchronicity compared to controls and the epileptic group at 4 weeks post-SE. Finally, network connectivity at 4 weeks post-SE was found to correlate with seizure onset (r = 0.858, p < .0001) and disease severity measured over 12 weeks (e.g. cingulate cortex: r = 0.863, p = .002), suggesting a possible network strengthening upon seizure reoccurrence. Our findings indicate that epileptogenesis is characterized by an initial hyposynchrony of brain networks and the disease-associated progression reflects disease severity.
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Neuroimaging Biomarkers of Experimental Epileptogenesis and Refractory Epilepsy. Int J Mol Sci 2019; 20:ijms20010220. [PMID: 30626103 PMCID: PMC6337422 DOI: 10.3390/ijms20010220] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 12/31/2018] [Accepted: 01/03/2019] [Indexed: 11/17/2022] Open
Abstract
This article provides an overview of neuroimaging biomarkers in experimental epileptogenesis and refractory epilepsy. Neuroimaging represents a gold standard and clinically translatable technique to identify neuropathological changes in epileptogenesis and longitudinally monitor its progression after a precipitating injury. Neuroimaging studies, along with molecular studies from animal models, have greatly improved our understanding of the neuropathology of epilepsy, such as the hallmark hippocampus sclerosis. Animal models are effective for differentiating the different stages of epileptogenesis. Neuroimaging in experimental epilepsy provides unique information about anatomic, functional, and metabolic alterations linked to epileptogenesis. Recently, several in vivo biomarkers for epileptogenesis have been investigated for characterizing neuronal loss, inflammation, blood-brain barrier alterations, changes in neurotransmitter density, neurovascular coupling, cerebral blood flow and volume, network connectivity, and metabolic activity in the brain. Magnetic resonance imaging (MRI) is a sensitive method for detecting structural and functional changes in the brain, especially to identify region-specific neuronal damage patterns in epilepsy. Positron emission tomography (PET) and single-photon emission computerized tomography are helpful to elucidate key functional alterations, especially in areas of brain metabolism and molecular patterns, and can help monitor pathology of epileptic disorders. Multimodal procedures such as PET-MRI integrated systems are desired for refractory epilepsy. Validated biomarkers are warranted for early identification of people at risk for epilepsy and monitoring of the progression of medical interventions.
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Immonen R, Smith G, Brady RD, Wright D, Johnston L, Harris NG, Manninen E, Salo R, Branch C, Duncan D, Cabeen R, Ndode-Ekane XE, Gomez CS, Casillas-Espinosa PM, Ali I, Shultz SR, Andrade P, Puhakka N, Staba RJ, O'Brien TJ, Toga AW, Pitkänen A, Gröhn O. Harmonization of pipeline for preclinical multicenter MRI biomarker discovery in a rat model of post-traumatic epileptogenesis. Epilepsy Res 2019; 150:46-57. [PMID: 30641351 DOI: 10.1016/j.eplepsyres.2019.01.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Revised: 12/12/2018] [Accepted: 01/05/2019] [Indexed: 02/07/2023]
Abstract
Preclinical imaging studies of posttraumatic epileptogenesis (PTE) have largely been proof-of-concept studies with limited animal numbers, and thus lack the statistical power for biomarker discovery. Epilepsy Bioinformatics Study for Antiepileptogenic Therapy (EpiBioS4Rx) is a pioneering multicenter trial investigating preclinical imaging biomarkers of PTE. EpiBios4Rx faced the issue of harmonizing the magnetic resonance imaging (MRI) procedures and imaging data metrics prior to its execution. We present here the harmonization process between three preclinical MRI facilities at the University of Eastern Finland (UEF), the University of Melbourne (Melbourne), and the University of California, Los Angeles (UCLA), and evaluate the uniformity of the obtained MRI data. Adult, male rats underwent a lateral fluid percussion injury (FPI) and were followed by MRI 2 days, 9 days, 1 month, and 5 months post-injury. Ex vivo scans of fixed brains were conducted 7 months post-injury as an end point follow-up. Four MRI modalities were used: T2-weighted imaging, multi-gradient-echo imaging, diffusion-weighted imaging, and magnetization transfer imaging, and acquisition parameters for each modality were tailored to account for the different field strengths (4.7 T and 7 T) and different MR hardwares used at the three participating centers. Pilot data collection resulted in comparable image quality across sites. In interim analysis (of data obtained by April 30, 2018), the within-site variation of the quantified signal properties was low, while some differences between sites remained. In T2-weighted images the signal-to-noise ratios were high at each site, being 35 at UEF, 48 at Melbourne, and 32 at UCLA (p < 0.05). The contrast-to-noise ratios were similar between the sites (9, 10, and 8, respectively). Magnetization transfer ratio maps had identical white matter/ gray matter contrast between the sites, with white matter showing 15% higher MTR than gray matter despite different absolute MTR values (MTR both in white and gray matter was 3% lower in Melbourne than at UEF, p < 0.05). Diffusion-weighting yielded different degrees of signal attenuation across sites, being 83% at UEF, 76% in Melbourne, and 80% at UCLA (p < 0.05). Fractional anisotropy values differed as well, being 0.81 at UEF, 0.73 in Melbourne, and 0.84 at UCLA (p < 0.05). The obtained values in sham animals showed low variation within each site and no change over time, suggesting high repeatability of the measurements. Quality control scans with phantoms demonstrated stable hardware performance over time. Timing of post-TBI scans was designed to target specific phases of the dynamic pathology, and the execution at different centers was highly accurate. Besides a few outliers, the 2-day scans were done within an hour from the target time point. At day 9, most animals were scanned within an hour from the target time point, and all but 2 outliers within 24 h from the target. The 1-month post-TBI scans were done within 31 ± 3 days. MRI procedures and animal physiology during scans were similar between the sites. Taken together, the 10% inter-site difference in FA and 3% difference in MTR values should be included into analysis as a covariate or balanced out in post-processing in order to detect disease-related effects on brain structure at the same scale. However, for a MRI biomarker for post-traumatic epileptogenesis to have realistic chance of being successfully translated to validation in clinical trials, it would need to be a robust TBI-induced structural change which tolerates the inter-site methodological variability described here.
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Affiliation(s)
- Riikka Immonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland.
| | - Gregory Smith
- Department of Neurology, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Rhys D Brady
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - David Wright
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia
| | - Leigh Johnston
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC 3052, Australia
| | - Neil G Harris
- Department of Neurology, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Eppu Manninen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Raimo Salo
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Craig Branch
- Albert Einstein College of Medicine, New York, NY 10461, USA
| | - Dominique Duncan
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA
| | - Ryan Cabeen
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA
| | - Xavier Ekolle Ndode-Ekane
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Cesar Santana Gomez
- Department of Neurology, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Pablo M Casillas-Espinosa
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - Idrish Ali
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - Sandy R Shultz
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - Pedro Andrade
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Noora Puhakka
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Richard J Staba
- Department of Neurology, David Geffen School of Medicine at University of California at Los Angeles, Los Angeles, CA 90095, USA
| | - Terence J O'Brien
- Departments of Neuroscience and Neurology, Central Clinical School, Alfred Health, Monash University, Melbourne, Victoria, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Parkville, Victoria, Australia
| | - Arthur W Toga
- USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA 90033, USA
| | - Asla Pitkänen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
| | - Olli Gröhn
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FIN-70211 Kuopio, Finland
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Bankstahl M, Bankstahl JP. Recent Advances in Radiotracer Imaging Hold Potential for Future Refined Evaluation of Epilepsy in Veterinary Neurology. Front Vet Sci 2017; 4:218. [PMID: 29326952 PMCID: PMC5733338 DOI: 10.3389/fvets.2017.00218] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/30/2017] [Indexed: 12/26/2022] Open
Abstract
Non-invasive nuclear imaging by positron emission tomography and single photon emission computed tomography has significantly contributed to epileptic focus localization in human neurology for several decades now. Offering functional insight into brain alterations, it is also of particular relevance for epilepsy research. Access to these techniques for veterinary medicine is becoming more and more relevant and has already resulted in first studies in canine patients. In view of the substantial proportion of drug-refractory epileptic dogs and cats, image-guided epileptic focus localization will be a prerequisite for selection of patients for surgical focus resection. Moreover, radiotracer imaging holds potential for a better understanding of the pathophysiology of underlying epilepsy syndromes as well as to forecast disease risk after epileptogenic brain insults. Importantly, recent advances in epilepsy research demonstrate the suitability and value of several novel radiotracers for non-invasive assessment of neuroinflammation, blood–brain barrier alterations, and neurotransmitter systems. It is desirable that veterinary epilepsy patients will also benefit from these promising developments in the medium term. This paper reviews the current use of radiotracer imaging in the veterinary epilepsy patient and suggests possible future directions for the technique.
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Affiliation(s)
- Marion Bankstahl
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Center of Systems Neuroscience Hannover, Hannover, Germany
| | - Jens P Bankstahl
- Department of Nuclear Medicine, Hannover Medical School, Hannover, Germany
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Hobson BA, Rowland DJ, Supasai S, Harvey DJ, Lein PJ, Garbow JR. A magnetic resonance imaging study of early brain injury in a rat model of acute DFP intoxication. Neurotoxicology 2017; 66:170-178. [PMID: 29183789 DOI: 10.1016/j.neuro.2017.11.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 11/21/2017] [Accepted: 11/24/2017] [Indexed: 11/18/2022]
Abstract
Current treatments for seizures induced by organophosphates do not protect sufficiently against progressive neurodegeneration or delayed cognitive impairment. Developing more effective therapeutic approaches has been challenging because the pathogenesis of these delayed consequences is poorly defined. Using magnetic resonance imaging (MRI), we previously reported brain lesions that persist for months in a rat model of acute intoxication with the OP, diisopropylfluorophosphate (DFP). However, the early spatiotemporal progression of these lesions remains unknown. To address this data gap, we used in vivo MRI to longitudinally monitor brain lesions during the first 3 d following acute DFP intoxication. Adult male Sprague Dawley rats acutely intoxicated with DFP (4mg/kg, sc) were MR imaged at 6, 12, 18, 24, 48, 72h post-DFP, and their brains then taken for correlative histology to assess neurodegeneration using FluoroJade C (FJC) staining. Acute DFP intoxication elicited moderate-to-severe seizure activity. T2-weighted (T2w) anatomic imaging revealed prominent lesions within the thalamus, piriform cortex, cerebral cortex, hippocampus, corpus striatum, and substantia nigra that corresponded to neurodegeneration, evident as bands of FJC positive cells. Semi-quantitative assessment of lesion severity demonstrated significant regional variation in the onset and progression of injury, and suggested that lesion severity may be modulated by isoflurane anesthesia. These results imply that the timing of therapeutic intervention for attenuating brain injury following OP intoxication may be regionally dependent, and that longitudinal assessment of OP-induced damage by MRI may be a powerful tool for assessing therapeutic response.
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Affiliation(s)
- Brad A Hobson
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA, 95616, United States.
| | - Douglas J Rowland
- Center for Molecular and Genomic Imaging, University of California, Davis, College of Engineering, Davis, CA, 95616, United States.
| | - Suangsuda Supasai
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA, 95616, United States.
| | - Danielle J Harvey
- Department of Public Health Sciences, University of California, Davis, School of Medicine, Davis, CA, 95616, United States.
| | - Pamela J Lein
- Department of Molecular Biosciences, University of California, Davis, School of Veterinary Medicine, Davis, CA, 95616, United States.
| | - Joel R Garbow
- Biomedical Magnetic Resonance Laboratory, Mallinckrodt Institute of Radiology, School of Medicine,Washington University in St. Louis, St. Louis, MO, 63110, United States.
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Mammillothalamic and Mammillotegmental Tracts as New Targets for Dementia and Epilepsy Treatment. World Neurosurg 2017; 110:133-144. [PMID: 29129763 DOI: 10.1016/j.wneu.2017.10.168] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/29/2017] [Accepted: 10/31/2017] [Indexed: 01/24/2023]
Abstract
BACKGROUND Recently, neuromodulation through deep brain stimulation (DBS) has appeared as a new surgical procedure in the treatment of some types of dementia and epilepsy. The mammillothalamic and mammillotegmental tracts are involved among the new targets. To our knowledge, a review article focused specifically on these mammillary body efferents is lacking in the medical literature. Their contribution to memory is, regrettably, often overlooked. METHODS A review of the relevant literature was conducted. RESULTS There is evidence that mammillary bodies can contribute to memory independently from hippocampal formation, but the mechanism is not yet known. Recent studies in animals have provided evidence for the specific roles of these mammillary body efferents in regulating memory independently. In animal studies, it has been shown that the disruption of the mammillothalamic tract inhibits seizures and that electrical stimulation of the mammillary body or mammillothalamic tract raises the seizure threshold. In humans, DBS targeting the mammillary body through the mammillothalamic tract or the stimulation of the anterior thalamic nucleus, especially in the areas closely related to the mammillothalamic tract, has been found effective in patients with medically refractory epilepsy. Nonetheless, little knowledge exists on the functional anatomy of the mammillary body efferents, and their role in the exact mechanism of epileptogenic activity and in the memory function of the human brain. CONCLUSIONS A comprehensive knowledge of the white matter anatomy of the mammillothalamic and mammillotegmental tracts is crucial since they have emerged as new DBS targets in the treatment of various disorders including dementia and epilepsy.
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