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Kloc ML, Holmes GL, Barry JM. Sex differences in cholinergic signaling affect functional outcomes for theta-gamma coordination in hippocampal subcircuits following experimental febrile status epilepticus. Epilepsia 2024; 65:2138-2151. [PMID: 38780490 PMCID: PMC11251858 DOI: 10.1111/epi.18017] [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: 12/11/2023] [Revised: 05/06/2024] [Accepted: 05/06/2024] [Indexed: 05/25/2024]
Abstract
OBJECTIVE Sex determines cognitive outcome in animal models of early life seizure, where males exhibit impaired hippocampal-dependent learning and memory compared with females. The physiological underpinnings of this sex effect are unclear. Cholinergic signaling is essential for the generation of hippocampal oscillations, and supplementation of cholinergic precursors prior to status epilepticus in immature male rats prevents subsequent memory deficits. We hypothesized that there are sex differences in acetylcholine circuits and their response to experimental febrile status epilepticus (eFSE). METHODS eFSE was induced in male and female rat pups. We transversed the hippocampus of postnatal day >60 control (CTL) and eFSE rats with a 64-channel laminar silicon probe to assay cholinergic-dependent theta oscillations under urethane anesthesia. Local field potential properties were compared during (1) baseline sensory stimulation, (2) pharmacological stimulation via acetylcholine reuptake blockade, and (3) sensory stimulation after muscarinic acetylcholine receptor block (atropine). RESULTS In all groups, a baseline tail pinch could elicit theta oscillations via corticohippocampal synaptic input. Following atropine, a tail pinch response could no longer be elicited in CTL male, CTL female, or eFSE female rats. In contrast, induced slow theta power in eFSE males after atropine was not decreased to spontaneous levels. Analysis of oscillation bandwidths revealed sex differences in acetylcholine modulation of theta frequency and slow gamma frequency and power. This study also identified significant effects of both sex and eFSE on baseline theta-gamma comodulation, indicating a loss of coupling in eFSE males and a potential gain of function in eFSE females. SIGNIFICANCE There are differences in cholinergic modulation of theta and gamma signal coordination between male and female rats. These differences may underlie worse cognitive outcomes in males following eFSE. Promoting the efficacy of muscarinic acetylcholine signaling prior to or following early life seizures could elucidate a mechanism for the temporal discoordination of neural signals within and between hippocampus and neocortex and provide a novel therapeutic approach for improving cognitive outcomes.
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Affiliation(s)
- Michelle L Kloc
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
| | - Gregory L Holmes
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
| | - Jeremy M Barry
- Epilepsy Cognition and Development Group, Department of Neurological Sciences, University of Vermont, Larner College of Medicine, Burlington, Vermont, USA
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2
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Balikci A, Eryilmaz U, Guler VK, Ilbay G. Tactile stimulation of young WAG/Rij rats prevents development of depression but not absence epilepsy. Front Behav Neurosci 2024; 18:1433431. [PMID: 38993266 PMCID: PMC11236540 DOI: 10.3389/fnbeh.2024.1433431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Accepted: 06/17/2024] [Indexed: 07/13/2024] Open
Abstract
Investigations in Wistar Albino Glaxo from Rijswijk (WAG/Rij) rats that are susceptible to genetic absence epilepsy have demonstrated that environmental modifications affect absence seizures. Previously, we showed that neonatal tactile stimulations produce disease-modifying effect on genetically determined absence epilepsy and associated depression in Wag/Rij rats. The study presented here examined the effect of TS during late ontogenesis (adolescence and young adulthood) on epilepsy and depression outcomes in this genetically epileptic rat strain. On postnatal day (PND) 38, male WAG/Rij rats randomly were assigned to either the tactile stimulation (TS), handled or control group (unhandled) with 8 animals in each group. Following a 7-day adaptation period to their new surroundings, the animals were submitted to tactile stimulation from PND 45 to PND 90, five days per week, for 5 min daily. The tactile-stimulated rat was removed from its cage, placed on the experimenter's lap, and had its neck and back gently stroked by the researcher. The handled rats were taken to another cage and left alone for 5 min daily from PND 45 to PND 90. The control rats were left undisturbed in their home cage, except for regular cage cleaning. After PND 90, all rats were left undisturbed until behavioral testing and EEG recording. When the animals were 7 months old, they were subjected to the sucrose consumption test (SCT) and the forced swimming test (FST). Electroencephalogram (EEG) recordings were made at 8 months of age in order to measure electroencephalographic seizure activity, thus, the spike-wave discharges (SWDs). Tactile-stimulated rats showed increased sucrose consumption and number of approaches to the sucrose solution in the SCT when compared with the handled and control rats. In the FST, rats in TS group showed lower immobility time and greater immobility latency, active swimming time and diving frequency than the handled and control rats. The duration and the number of seizures were not different amongst the groups. The data obtained suggest that TS in young rats is able to prevent depression in WAG/Rij rats.
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Affiliation(s)
- Aymen Balikci
- Department of Physiology, Faculty of Medicine, Kocaeli University, İzmit, Türkiye
| | - Ugur Eryilmaz
- Department of Physiology, Faculty of Medicine, Kocaeli University, İzmit, Türkiye
| | - Vildan Keles Guler
- Department of Physiology, Faculty of Medicine, Kocaeli University, İzmit, Türkiye
| | - Gul Ilbay
- Department of Physiology, Faculty of Medicine, Kocaeli University, İzmit, Türkiye
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3
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Crespo M, León-Navarro DA, Martín M. Maternal Caffeine Consumption during Gestation and Lactation Abolishes Cortical Oxidative Stress and Restores Na +/K +-ATPase Activity in Neonates Exposed to Hyperthermia-Induced Seizures. Biomedicines 2023; 11:3292. [PMID: 38137513 PMCID: PMC10741554 DOI: 10.3390/biomedicines11123292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 12/05/2023] [Accepted: 12/09/2023] [Indexed: 12/24/2023] Open
Abstract
Caffeine is a psychoactive substance that is widely consumed by individuals of various demographics, including pregnant women. It can readily cross the blood-brain and placental barriers, easily reaching the fetal brain. In addition, caffeine has also shown antioxidant properties, as its consumption reduces oxidative stress in various pathologies, including epilepsy. Febrile seizures (FS) are among the most common convulsive disorders in infants and young children. Here, we used an animal model of FS to learn whether maternal caffeine (1 g/L) intake consumption during gestation and lactation could exert beneficial effects on the rat cortex. Neonatal development was analyzed by measuring pinna opening, eye opening, righting reflex on the surface, and geotaxis reflex. Five and twenty days after HIS, the rats were euthanized, and plasma membranes and cytosolic fractions were isolated from their cortex brain. The enzymatic activities of glutathione reductase, glutathione S-transferase, Na+/K+-ATPase, and Mg2+-ATPase, as well as the levels of thiobarbituric acid reacting substances, were quantified. Results showed that maternal caffeine intake eliminates oxidative stress and normalizes Na+/K+-ATPase activity disrupted by HIS and also affects some parameters relating to the neurodevelopment of neonates. As FS in infants has been related to epilepsy in adults, the antioxidant properties of caffeine could prevent potential damage from hyperthermia.
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Affiliation(s)
- María Crespo
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - David Agustín León-Navarro
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - Mairena Martín
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, School of Medicine of Ciudad Real, Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain;
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4
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Cheng Y, Zhai Y, Yuan Y, Li H, Zhao W, Fan Z, Zhou L, Gao X, Zhan Y, Sun H. Xenon inhalation attenuates neuronal injury and prevents epilepsy in febrile seizure Sprague-Dawley pups. Front Cell Neurosci 2023; 17:1155303. [PMID: 37645594 PMCID: PMC10461106 DOI: 10.3389/fncel.2023.1155303] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 07/27/2023] [Indexed: 08/31/2023] Open
Abstract
Background Febrile seizures (FS) usually occur in childhood and may cause irreversible neuronal damage, cognitive functional defects, and an increase in the risk of epilepsy later in life. Anti-epileptic drugs (AEDs), currently used to treat FS in children, can relieve seizures. However, their effects in preventing the risk of developing epilepsy in later life are unsatisfactory. Moreover, AEDs may damage child brain development. Here, we evaluated the efficiency of xenon in treating prolonged FS (PFS) and preventing epilepsy in Sprague-Dawley pups. Methods Prolonged FS was induced by hyperthermic treatment. After 90 min of PFS, the pups in the xenon treatment group were immediately treated with 70% xenon/21% oxygen/9% nitrogen for 60 min. The levels of glutamate, mitochondrial oxidative stress, mitophagy, and neuronal injury, seizures, learning, and memory functions were measured at specific time points. Results Neonatal period PFS led to spontaneous seizure, learning and memory dysfunction, accompanied by increased levels of glutamate, mitochondrial oxidative stress, mitophagy, and neuronal injury. Xenon treatment alleviated the changes caused by PFS and reduced the risk of PFS developing into epilepsy later. Conclusion Our results suggest that xenon inhalation could be a potential therapeutic strategy to attenuate neuronal injury and prevent epilepsy in patients with FS.
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Affiliation(s)
- Yao Cheng
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Yujie Zhai
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Yi Yuan
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Hao Li
- School of Medical Imaging, Binzhou Medical University, Yantai, China
| | - Wenke Zhao
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Zhenhai Fan
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Ling Zhou
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Xue Gao
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
| | - Yan Zhan
- Department of Neurology, Yantai Affiliated Hospital of Binzhou Medical University, Yantai, China
| | - Hongliu Sun
- School of Pharmaceutical Sciences, Binzhou Medical University, Yantai, China
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Seyedhosseinzadeh N, Saeedi N, Hashemi A, Homam SM. Alterations in Seizure Frequency in Patients with Epilepsy Following Coronavirus Disease 2019. J Epilepsy Res 2023; 13:7-12. [PMID: 37720679 PMCID: PMC10501815 DOI: 10.14581/jer.23002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2022] [Revised: 04/30/2023] [Accepted: 05/08/2023] [Indexed: 09/19/2023] Open
Abstract
Background and Purpose During the coronavirus disease 19 (COVID-19) pandemic, a considerable number of studies have focused on the difficulties for accessing the medical services and telemedicine-related issues. However, it is not clear whether COVID-19 affects the clinical course of epilepsy. Therefore, in the current study we aimed to assess the effects of COVID-19 infection on seizure frequency in patients with epilepsy (PWE). Methods We evaluated PWE who consecutively referred to the neurology clinics of 22 Bahman and Qaem hospitals, who had experienced a recent polymerase chain reaction-confirmed-COVID-19 infection. Data were collected through a pre-defined electronic questionnaire. Results A total of 104 patients were included. Females represented 52% of the population. The mean age of the patients was 36.73±17.87. Thirty-six patients (34%) reported increased seizure frequency. The mean age of the patients who had exacerbated seizure frequency was significantly lower than the non-exacerbated group (27.50±9.8 vs. 40.14±18.39; p=0.005). The number of the male patients were significantly higher in the exacerbated group (52% vs. 25%; p=0.014). The majority of exacerbated group had a history of drug resistance (44.4% vs. 8.5%; p=0.022). The number of epileptic seizures before COVID-19 infection was higher in the exacerbated (p=0.04). Conclusions About 34% of PWE experienced exacerbated epileptic seizures after COVID-19 infection. Male patients, young patients, patients with the history of drug resistance, and the patients who had higher seizure frequency were at increased risk for seizure exacerbation. Our results highlight the importance of screening, early diagnosis, and treatment in PWE.
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Affiliation(s)
| | - Nikoo Saeedi
- Student Research Committee, Islamic Azad University, Mashhad Branch, Mashhad, Iran
| | - Anahita Hashemi
- Student Research Committee, Islamic Azad University, Mashhad Branch, Mashhad, Iran
| | - Seyed Mehran Homam
- Department of Neurology, Islamic Azad University, Mashhad Branch, Mashhad, Iran
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Bando SY, Bertonha FB, Menezes PHN, Takahara AK, Khaled NA, Santos P, S Junqueira M, Cesar RM, Moreira-Filho CA. Transcriptomic analysis reveals distinct adaptive molecular mechanism in the hippocampal CA3 from rats susceptible or not-susceptible to hyperthermia-induced seizures. Sci Rep 2023; 13:10265. [PMID: 37355705 PMCID: PMC10290664 DOI: 10.1038/s41598-023-37535-w] [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: 04/27/2023] [Accepted: 06/23/2023] [Indexed: 06/26/2023] Open
Abstract
Febrile seizures during early childhood are a relevant risk factor for the development of mesial temporal lobe epilepsy. Nevertheless, the molecular mechanism induced by febrile seizures that render the brain susceptible or not-susceptible to epileptogenesis remain poorly understood. Because the temporal investigation of such mechanisms in human patients is impossible, rat models of hyperthermia-induced febrile seizures have been used for that purpose. Here we conducted a temporal analysis of the transcriptomic and microRNA changes in the ventral CA3 of rats that develop (HS group) or not-develop (HNS group) seizures after hyperthermic insult on the eleventh postnatal day. The selected time intervals corresponded to acute, latent, and chronic phases of the disease. We found that the transcriptional differences between the HS and the HNS groups are related to inflammatory pathways, immune response, neurogenesis, and dendritogenesis in the latent and chronic phases. Additionally, the HNS group expressed a greater number of miRNAs (some abundantly expressed) as compared to the HS group. These results indicate that HNS rats were able to modulate their inflammatory response after insult, thus presenting better tissue repair and re-adaptation. Potential therapeutic targets, including genes, miRNAs and signaling pathways involved in epileptogenesis were identified.
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Affiliation(s)
- Silvia Y Bando
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, 05403-900, Brazil.
| | - Fernanda B Bertonha
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, 05403-900, Brazil
| | - Pedro H N Menezes
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, 05403-900, Brazil
| | - André K Takahara
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, 05403-900, Brazil
| | - Nathália A Khaled
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, 05403-900, Brazil
| | - Paula Santos
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, 05403-900, Brazil
| | - Mara S Junqueira
- Department of Radiology and Oncology, Centro de Investigação Translacional em Oncologia-Instituto do Câncer do Estado de São Paulo, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, 05403-000, Brazil
| | - Roberto M Cesar
- Department of Computer Science, Instituto de Matemática e Estatística da Universidade de São Paulo, São Paulo, SP, 05508-040, Brazil
| | - Carlos A Moreira-Filho
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, 05403-900, Brazil
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7
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Arida RM. Physical Exercise as a Strategy to Reduce Seizure Susceptibility. PHARMACORESISTANCE IN EPILEPSY 2023:453-477. [DOI: 10.1007/978-3-031-36526-3_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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8
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Crespo M, León-Navarro DA, Martín M. Na +/K +- and Mg 2+-ATPases and Their Interaction with AMPA, NMDA and D 2 Dopamine Receptors in an Animal Model of Febrile Seizures. Int J Mol Sci 2022; 23:ijms232314638. [PMID: 36498965 PMCID: PMC9737571 DOI: 10.3390/ijms232314638] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 11/05/2022] [Accepted: 11/15/2022] [Indexed: 11/25/2022] Open
Abstract
Febrile seizures (FS) are one of the most common seizure disorders in childhood which are classified into short and prolonged, depending on their duration. Short FS are usually considered as benign. However, epidemiological studies have shown an association between prolonged FS and temporal lobe epilepsy. The development of animal models of FS has been very useful to investigate the mechanisms and the consequences of FS. One of the most used, the "hair dryer model", has revealed that prolonged FS may lead to temporal lobe epilepsy by altering neuronal function. Several pieces of evidence suggest that Na+/ K+-ATPase and Mg2+-ATPase may play a role in this epileptogenic process. In this work, we found that hyperthermia-induced seizures (HIS) significantly increased the activity of Na+/ K+-ATPase and Mg2+-ATPase five and twenty days after hyperthermic insult, respectively. These effects were diminished in response to AMPA, D2 dopamine A1 and A2A receptors activation, respectively. Furthermore, HIS also significantly increased the protein level of the AMPA subunit GluR1. Altogether, the increased Na+/ K+-ATPase and Mg2+-ATPase agree well with the presence of protective mechanisms. However, the reduction in ATPase activities in the presence of NMDA and AMPA suggest an increased propensity for epileptic events in adults.
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Affiliation(s)
- María Crespo
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
| | - David Agustín León-Navarro
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
- Correspondence: ; Tel.: +34-926-052-114
| | - Mairena Martín
- Department of Inorganic, Organic Chemistry and Biochemistry, Faculty of Chemical and Technological Sciences, School of Medicine of Ciudad Real, Regional Centre of Biomedical Research (CRIB), Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain
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9
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Gao X, Fang D, Liang Y, Deng X, Chen N, Zeng M, Luo M. Circular RNAs as emerging regulators in COVID-19 pathogenesis and progression. Front Immunol 2022; 13:980231. [PMID: 36439162 PMCID: PMC9681929 DOI: 10.3389/fimmu.2022.980231] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 10/19/2022] [Indexed: 11/11/2022] Open
Abstract
Coronavirus disease 2019 (COVID-19), an infectious acute respiratory disease caused by a newly emerging RNA virus, is a still-growing pandemic that has caused more than 6 million deaths globally and has seriously threatened the lives and health of people across the world. Currently, several drugs have been used in the clinical treatment of COVID-19, such as small molecules, neutralizing antibodies, and monoclonal antibodies. In addition, several vaccines have been used to prevent the spread of the pandemic, such as adenovirus vector vaccines, inactivated vaccines, recombinant subunit vaccines, and nucleic acid vaccines. However, the efficacy of vaccines and the onset of adverse reactions vary among individuals. Accumulating evidence has demonstrated that circular RNAs (circRNAs) are crucial regulators of viral infections and antiviral immune responses and are heavily involved in COVID-19 pathologies. During novel coronavirus infection, circRNAs not only directly affect the transcription process and interfere with viral replication but also indirectly regulate biological processes, including virus-host receptor binding and the immune response. Consequently, understanding the expression and function of circRNAs during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection will provide novel insights into the development of circRNA-based methods. In this review, we summarize recent progress on the roles and underlying mechanisms of circRNAs that regulate the inflammatory response, viral replication, immune evasion, and cytokines induced by SARS-CoV-2 infection, and thus highlighting the diagnostic and therapeutic challenges in the treatment of COVID-19 and future research directions.
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Affiliation(s)
- Xiaojun Gao
- Key Laboratory of Medical Electrophysiology, Ministry of Education, Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China
- Laboratory for Cardiovascular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Dan Fang
- Key Laboratory of Medical Electrophysiology, Ministry of Education, Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China
- Laboratory for Cardiovascular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Yu Liang
- College of Integrated Traditional Chinese and Western Medicine, Affiliated Hospital of Traditional Chinese Medicine, Southwest Medical University, Luzhou, Sichuan, China
| | - Xin Deng
- Key Laboratory of Medical Electrophysiology, Ministry of Education, Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China
- Laboratory for Cardiovascular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Ni Chen
- Key Laboratory of Medical Electrophysiology, Ministry of Education, Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China
- Laboratory for Cardiovascular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
| | - Min Zeng
- Department of Pharmacy, the Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan, China
| | - Mao Luo
- Key Laboratory of Medical Electrophysiology, Ministry of Education, Drug Discovery Research Center, Southwest Medical University, Luzhou, Sichuan, China
- Laboratory for Cardiovascular Pharmacology, Department of Pharmacology, School of Pharmacy, Southwest Medical University, Luzhou, Sichuan, China
- College of Integrated Traditional Chinese and Western Medicine, Affiliated Hospital of Traditional Chinese Medicine, Southwest Medical University, Luzhou, Sichuan, China
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10
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Functional network connectivity imprint in febrile seizures. Sci Rep 2022; 12:3267. [PMID: 35228583 PMCID: PMC8885759 DOI: 10.1038/s41598-022-07173-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/10/2022] [Indexed: 11/11/2022] Open
Abstract
Complex febrile seizures (CFS), a subset of paediatric febrile seizures (FS), have been studied for their prognosis, epileptogenic potential and neurocognitive outcome. We evaluated their functional connectivity differences with simple febrile seizures (SFS) in children with recent-onset FS. Resting-state fMRI (rs-fMRI) datasets of 24 children with recently diagnosed FS (SFS-n = 11; CFS-n = 13) were analysed. Functional connectivity (FC) was estimated using time series correlation of seed region–to-whole-brain-voxels and network topology was assessed using graph theory measures. Regional connectivity differences were correlated with clinical characteristics (FDR corrected p < 0.05). CFS patients demonstrated increased FC of the bilateral middle temporal pole (MTP), and bilateral thalami when compared to SFS. Network topology study revealed increased clustering coefficient and decreased participation coefficient in basal ganglia and thalamus suggesting an inefficient-unbalanced network topology in patients with CFS. The number of seizure recurrences negatively correlated with the integration of Left Thalamus (r = − 0.58) and FC of Left MTP to 'Right Supplementary Motor and left Precentral' gyrus (r = − 0.53). The FC of Right MTP to Left Amygdala, Putamen, Parahippocampal, and Orbital Frontal Cortex (r = 0.61) and FC of Left Thalamus to left Putamen, Pallidum, Caudate, Thalamus Hippocampus and Insula (r 0.55) showed a positive correlation to the duration of the longest seizure. The findings of the current study report altered connectivity in children with CFS proportional to the seizure recurrence and duration. Regardless of the causal/consequential nature, such observations demonstrate the imprint of these disease-defining variables of febrile seizures on the developing brain.
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11
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Jiang XY, Zhou WH. [Influence of coronavirus disease 2019 on the nervous system of children]. ZHONGGUO DANG DAI ER KE ZA ZHI = CHINESE JOURNAL OF CONTEMPORARY PEDIATRICS 2021; 23:530-535. [PMID: 34020746 PMCID: PMC8140346 DOI: 10.7499/j.issn.1008-8830.2012115] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 01/22/2021] [Indexed: 06/12/2023]
Abstract
Coronavirus disease 2019 (COVID-19) has become a worldwide pandemic and can occur at any age, including children. Children with COVID-19 can develop the clinical symptoms of multiple systems, among which symptoms of the nervous system have been reported increasingly, and thus it is particularly important to understand COVID-19-associated neurological damage in children. This article reviews the mechanisms and types of COVID-19-associated neurological damage in children.
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Affiliation(s)
- Xin-Yi Jiang
- Department of Neonatology, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China
| | - Wen-Hao Zhou
- Department of Neonatology, Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, Zhejiang 325000, China
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12
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Crespo M, León-Navarro DA, Martín M. Glutamatergic System is Affected in Brain from an Hyperthermia-Induced Seizures Rat Model. Cell Mol Neurobiol 2021; 42:1501-1512. [PMID: 33492599 DOI: 10.1007/s10571-021-01041-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 01/11/2021] [Indexed: 12/22/2022]
Abstract
One of the most frequent neurological disorders in children is febrile seizures (FS), a risk for epilepsy in adults. Glutamate is the main excitatory neurotransmitter in CNS acting through ionotropic and metabotropic receptors. Excess of glutamate in the extracellular space elicits excitotoxicity and has been associated with neurological disorders, such as epilepsy. The removal of extracellular glutamate by excitatory amino acid transporters (EATT) plays an important neuroprotective role. GLT-1 is the main EAAT present in the cortex brain. On the other hand, an increase in metabotropic glutamate receptors 5 (mGlu5R) levels or their overstimulation have been related to the appearance of seizure events in different animal models and in temporal lobe epilepsy in humans. In this work, the status of several components of the glutamatergic system has been analysed in the cortex brain from an FS rat model at short (48 h) and long (20 days) term after hyperthermia-induced seizures. At the short term, we detected increased GLT-1 levels, reduced glutamate concentration, and unchanged mGlu5R levels, without neuronal loss. However, at the long term, an increase in mGlu5R levels together with a decrease in both GLT-1 and glutamate levels were observed. These changes were associated with the appearance of an anxious phenotype. These results suggest a neuroprotective role of the glutamatergic components mGlu5R and GLT-1 at the short term. However, this neuroprotective effect seems to be lost at the long term, leading to an anxious phenotype and suggesting an increased vulnerability and propensity to epileptic events in adults.
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Affiliation(s)
- M Crespo
- Department of Inorganic, Organic and Biochemistry, Faculty of Chemical and Technological Sciences, School of Medicine of Ciudad Real, Universidad de Castilla-La Mancha, Regional Centre of Biomedical Research (CRIB), Avenida Camilo José Cela, 10, 13071, Ciudad Real, Spain
| | - D A León-Navarro
- Department of Inorganic, Organic and Biochemistry, Faculty of Chemical and Technological Sciences, School of Medicine of Ciudad Real, Universidad de Castilla-La Mancha, Regional Centre of Biomedical Research (CRIB), Avenida Camilo José Cela, 10, 13071, Ciudad Real, Spain.
| | - M Martín
- Department of Inorganic, Organic and Biochemistry, Faculty of Chemical and Technological Sciences, School of Medicine of Ciudad Real, Universidad de Castilla-La Mancha, Regional Centre of Biomedical Research (CRIB), Avenida Camilo José Cela, 10, 13071, Ciudad Real, Spain
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13
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How does the COVID-19 cause seizure and epilepsy in patients? The potential mechanisms. Mult Scler Relat Disord 2020; 46:102535. [PMID: 33010584 PMCID: PMC7521932 DOI: 10.1016/j.msard.2020.102535] [Citation(s) in RCA: 83] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/22/2020] [Accepted: 09/25/2020] [Indexed: 01/08/2023]
Abstract
The new coronavirus has spread throughout the world in a very short time and now has become a pandemic. Most infected people have symptoms such as dry cough, dyspnea, tiredness, and fever. However, the Covid-19 infection disrupts various organs, including the liver, kidney, and nervous system. Common neurological symptoms of the Covid-19 infection include delirium, confusion, headache, and loss of sense of smell and taste. In rare cases it can cause stroke and epilepsy. The virus enters the nervous system either directly through nerve pathways or indirectly through the ACE2 receptor. The neurological symptoms of a Covid-19 infection in the brain are mainly due to either the entry of pro-inflammatory cytokines into the nervous system or the production of these cytokines by microglia and astrocytes. Pro-inflammatory cytokines can cause blood-brain barrier disruption, increase in glutamate and aspartate and reduce GABA levels, impairs the function of ion channels, and finally, high levels of cytokines can cause epilepsy. Understanding the potential mechanisms is necessary to gain better insight into COVID-19 induced seizure pathogenesis and to design the correct treatment strategies to achieve appropriate treatment for seizure and epilepsy.
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14
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Recurrent seizures cause immature brain injury and changes in GABA a receptor α1 and γ2 subunits. Epilepsy Res 2020; 163:106328. [DOI: 10.1016/j.eplepsyres.2020.106328] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/05/2020] [Accepted: 03/31/2020] [Indexed: 02/07/2023]
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15
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Crespo M, León‐Navarro DA, Ruíz MÁ, Martín M. Hyperthermia‐induced seizures produce long‐term effects on the functionality of adenosine A
1
receptor in rat cerebral cortex. Int J Dev Neurosci 2020; 80:1-12. [DOI: 10.1002/jdn.10000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 12/09/2019] [Indexed: 12/12/2022] Open
Affiliation(s)
- María Crespo
- Departamento de Química Inorgánica Orgánica y Bioquímica Facultad de Ciencias y Tecnologías Químicas Centro Regional de Investigaciones Biomédicas Universidad de Castilla‐La Mancha Ciudad Real Spain
| | - David Agustín León‐Navarro
- Departamento de Química Inorgánica Orgánica y Bioquímica Facultad de Ciencias y Tecnologías Químicas Centro Regional de Investigaciones Biomédicas Universidad de Castilla‐La Mancha Ciudad Real Spain
| | - María Ángeles Ruíz
- Departamento de Química Inorgánica Orgánica y Bioquímica Facultad de Ciencias y Tecnologías Químicas Centro Regional de Investigaciones Biomédicas Universidad de Castilla‐La Mancha Ciudad Real Spain
| | - Mairena Martín
- Departamento de Química Inorgánica Orgánica y Bioquímica Facultad de Ciencias y Tecnologías Químicas Facultad de Medicina de Ciudad Real Centro Regional de Investigaciones Biomédicas Universidad de Castilla‐La Mancha Ciudad Real Spain
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16
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Salgueiro-Pereira AR, Duprat F, Pousinha PA, Loucif A, Douchamps V, Regondi C, Ayrault M, Eugie M, Stunault MI, Escayg A, Goutagny R, Gnatkovsky V, Frassoni C, Marie H, Bethus I, Mantegazza M. A two-hit story: Seizures and genetic mutation interaction sets phenotype severity in SCN1A epilepsies. Neurobiol Dis 2019; 125:31-44. [DOI: 10.1016/j.nbd.2019.01.006] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Revised: 12/14/2018] [Accepted: 01/14/2019] [Indexed: 01/07/2023] Open
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17
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Harwood JC, Kent NA, Allen ND, Harwood AJ. Nucleosome dynamics of human iPSC during neural differentiation. EMBO Rep 2019; 20:embr.201846960. [PMID: 31036712 PMCID: PMC6549019 DOI: 10.15252/embr.201846960] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 03/29/2019] [Accepted: 04/02/2019] [Indexed: 01/07/2023] Open
Abstract
Nucleosome positioning is important for neurodevelopment, and genes mediating chromatin remodelling are strongly associated with human neurodevelopmental disorders. To investigate changes in nucleosome positioning during neural differentiation, we generate genome‐wide nucleosome maps from an undifferentiated human‐induced pluripotent stem cell (hiPSC) line and after its differentiation to the neural progenitor cell (NPC) stage. We find that nearly 3% of nucleosomes are highly positioned in NPC, but significantly, there are eightfold fewer positioned nucleosomes in pluripotent cells, indicating increased positioning during cell differentiation. Positioned nucleosomes do not strongly correlate with active chromatin marks or gene transcription. Unexpectedly, we find a small population of nucleosomes that occupy similar positions in pluripotent and neural progenitor cells and are found at binding sites of the key gene regulators NRSF/REST and CTCF. Remarkably, the presence of these nucleosomes appears to be independent of the associated regulatory complexes. Together, these results present a scenario in human cells, where positioned nucleosomes are sparse and dynamic, but may act to alter gene expression at a distance via the structural conformation at sites of chromatin regulation.
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Affiliation(s)
- Janet C Harwood
- MRC Centre for Neuropsychiatric Genetics & Genomics, Cardiff University, Cardiff, UK
| | | | | | - Adrian J Harwood
- School of Biosciences, Cardiff University, Cardiff, UK .,Neuroscience and Mental Health Research Institute (NMHRI), Cardiff University, Cardiff, UK
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18
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Saboory E, Ghadimkhani M, Roshan-Milani S, Derafshpour L, Mohammadi S, Dindarian S, Mohammadi H. Effect of early-life inflammation and magnesium sulfate on hyperthermia-induced seizures in infant rats: Susceptibility to pentylenetetrazol-induced seizures later in life. Dev Psychobiol 2018; 61:96-106. [PMID: 30338516 DOI: 10.1002/dev.21781] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Revised: 08/08/2018] [Accepted: 08/20/2018] [Indexed: 12/21/2022]
Abstract
This study investigated the effect of inflammation and MgSO4 pretreatment on behaviors caused by hyperthermia (HT) and the effect of these interventions on PTZ-induced seizure a week later. In this experimental study, rat pups experienced inflammation on postnatal day 10 (P10). On P18-19, the pups received either saline or MgSO4 then subjected to hyperthermia. On P25-26, PTZ-induced seizure was initiated in the rats. Neonatal inflammation increased the susceptibility to HT-induced seizure. Inflammation and HT increased the susceptibility to PTZ-induced seizure. Pretreatment with MgSO4 before hyperthermia decreased the susceptibility to both HT- and PTZ-induced seizure. Furthermore, calcium and magnesium blood levels significantly decreased compared to control rats. It can be concluded that neonatal inflammation potentiates while pretreatment with MgSO4 attenuates HT-induced seizures. Also, neonatal inflammation and HT potentiate PTZ-induced seizure initiated one week later.
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Affiliation(s)
- Ehsan Saboory
- Neurophysiology Research Center, Urmia University of Medical Sciences, Urmia, Iran.,Department of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Maryam Ghadimkhani
- Neurophysiology Research Center, Urmia University of Medical Sciences, Urmia, Iran
| | - Shiva Roshan-Milani
- Neurophysiology Research Center, Urmia University of Medical Sciences, Urmia, Iran.,Department of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Leila Derafshpour
- Neurophysiology Research Center, Urmia University of Medical Sciences, Urmia, Iran.,Department of Physiology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Sedra Mohammadi
- Student Research Committee, Urmia University of Medical Sciences, Urmia, Iran
| | - Sina Dindarian
- Student Research Committee, Urmia University of Medical Sciences, Urmia, Iran
| | - Hozan Mohammadi
- Student Research Committee, Urmia University of Medical Sciences, Urmia, Iran
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19
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Crespo M, León-Navarro DA, Martín M. Early-life hyperthermic seizures upregulate adenosine A 2A receptors in the cortex and promote depressive-like behavior in adult rats. Epilepsy Behav 2018; 86:173-178. [PMID: 30017837 DOI: 10.1016/j.yebeh.2018.06.048] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2018] [Revised: 06/07/2018] [Accepted: 06/25/2018] [Indexed: 10/28/2022]
Abstract
Febrile seizures (FS) represent one of the most frequent convulsive disorders in children which can be classified into simple and prolonged depending on the duration. Although simple FS are generally considered as benign, there is controversy about the outcome of prolonged FS. Here, we have used an animal model of prolonged FS to investigate persistent neurochemical and behavioral alterations in adult rats. Hyperthermic seizures were induced in 12-day-old rats using a warmed air stream from a hair dryer. Neonates exhibited arrest of heat-induced hyperkinesis followed by body flexion and rearing and falling over associated with hindlimb clonus seizures (stage 5 on Racine scale criteria) after hyperthermic induction. After 48 days, the animals were assayed on dark-light box and forced swim tests in order to detect if rats will show signs of anxiety or depression. Finally, animals were sacrificed 56 days after hyperthermia-induced seizures (HIS), and their effects on adenosine A2A receptor signaling and 5'-nucleotidase activity were studied in plasma membranes from the cerebral cortex by using radioligand-binding assay and by measuring the activities of adenylate cyclase and 5'-nucleotidase. Results obtained have shown that adult rats submitted to HIS during the neonatal period showed depressive-like behavior. Furthermore, animals exposed to hyperthermic insult showed an increase in A2A receptor level which was also accompanied by an increase in A2A receptor functionality.
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Affiliation(s)
- María Crespo
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencias y Tecnologías Químicas/Facultad de Medicina de Ciudad Real, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Avenida Camilo José Cela, 10, 13071 Ciudad Real, Spain
| | - David Agustín León-Navarro
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencias y Tecnologías Químicas/Facultad de Medicina de Ciudad Real, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Avenida Camilo José Cela, 10, 13071 Ciudad Real, Spain.
| | - Mairena Martín
- Departamento de Química Inorgánica, Orgánica y Bioquímica, Facultad de Ciencias y Tecnologías Químicas/Facultad de Medicina de Ciudad Real, Centro Regional de Investigaciones Biomédicas, Universidad de Castilla-La Mancha, Avenida Camilo José Cela, 10, 13071 Ciudad Real, Spain
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20
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Gales JM, Prayson RA. Chronic inflammation in refractory hippocampal sclerosis-related temporal lobe epilepsy. Ann Diagn Pathol 2017; 30:12-16. [DOI: 10.1016/j.anndiagpath.2017.05.009] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2017] [Accepted: 05/15/2017] [Indexed: 02/07/2023]
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21
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Pujar SS, Seunarine KK, Martinos MM, Neville BGR, Scott RC, Chin RFM, Clark CA. Long-term white matter tract reorganization following prolonged febrile seizures. Epilepsia 2017; 58:772-780. [PMID: 28332711 PMCID: PMC5484997 DOI: 10.1111/epi.13724] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2017] [Indexed: 12/17/2022]
Abstract
Objective Diffusion magnetic resonance imaging (MRI) studies have demonstrated acute white matter changes following prolonged febrile seizures (PFS), but their longer‐term evolution is unknown. We investigated a population‐based cohort to determine white matter diffusion properties 8 years after PFS. Methods We used diffusion tensor imaging (DTI) and applied Tract‐Based Spatial Statistics for voxel‐wise comparison of white matter microstructure between 26 children with PFS and 27 age‐matched healthy controls. Age, gender, handedness, and hippocampal volumes were entered as covariates for voxel‐wise analysis. Results Mean duration between the episode of PFS and follow‐up was 8.2 years (range 6.7–9.6). All children were neurologically normal, and had normal conventional neuroimaging. On voxel‐wise analysis, compared to controls, the PFS group had (1) increased fractional anisotropy in early maturing central white matter tracts, (2) increased mean and axial diffusivity in several peripheral white matter tracts and late‐maturing central white matter tracts, and (3) increased radial diffusivity in peripheral white matter tracts. None of the tracts had reduced fractional anisotropy or diffusivity indices in the PFS group. Significance In this homogeneous, population‐based sample, we found increased fractional anisotropy in early maturing central white matter tracts and increased mean and axial diffusivity with/without increased radial diffusivity in several late‐maturing peripheral white matter tracts 8 years post‐PFS. We propose disruption in white matter maturation secondary to seizure‐induced axonal injury, with subsequent neuroplasticity and microstructural reorganization as a plausible explanation.
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Affiliation(s)
- Suresh S Pujar
- Neurosciences Unit, UCL Great Ormond Street Institute of Child Health, London, United Kingdom.,Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom.,Young Epilepsy, Lingfield, Surrey, United Kingdom
| | - Kiran K Seunarine
- Imaging and Biophysics Unit, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Marina M Martinos
- Developmental Cognitive Neuroscience Unit, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Brian G R Neville
- Neurosciences Unit, UCL Great Ormond Street Institute of Child Health, London, United Kingdom.,Young Epilepsy, Lingfield, Surrey, United Kingdom
| | - Rod C Scott
- Neurosciences Unit, UCL Great Ormond Street Institute of Child Health, London, United Kingdom.,Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom.,Young Epilepsy, Lingfield, Surrey, United Kingdom.,Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont, U.S.A
| | - Richard F M Chin
- Neurosciences Unit, UCL Great Ormond Street Institute of Child Health, London, United Kingdom.,Muir Maxwell Epilepsy Centre, Department of Child Life and Health, The University of Edinburgh, Edinburgh, United Kingdom
| | - Chris A Clark
- Imaging and Biophysics Unit, UCL Great Ormond Street Institute of Child Health, London, United Kingdom
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22
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Hall AM, Brennan GP, Nguyen TM, Singh-Taylor A, Mun HS, Sargious MJ, Baram TZ. The Role of Sirt1 in Epileptogenesis. eNeuro 2017; 4:ENEURO.0301-16.2017. [PMID: 28197553 PMCID: PMC5301079 DOI: 10.1523/eneuro.0301-16.2017] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/21/2017] [Accepted: 01/22/2017] [Indexed: 01/08/2023] Open
Abstract
The mechanisms by which brain insults lead to subsequent epilepsy remain unclear. Insults, including trauma, stroke, tumors, infections, and long seizures [status epilepticus (SE)], create a neuronal state of increased metabolic demand or decreased energy supply. Neurons express molecules that monitor their metabolic state, including sirtuins (Sirts). Sirtuins deacetylate cytoplasmic proteins and nuclear histones, and their epigenetic modulation of the chromatin governs the expression of many genes, influencing neuronal properties. Thus, sirtuins are poised to enduringly modulate neuronal properties following SE, potentially contributing to epileptogenesis, a hypothesis supported by the epilepsy-attenuating effects of blocking a downstream target of Sirt1, Neuron-Restrictive Silencer Factor (NRSF) also know as REST (RE1-Silencing Transcription factor). Here we used an adult male rat model of epileptogenesis provoked by kainic acid-induced SE (KA-SE). We assessed KA-SE-provoked Sirt1 activity, infused a Sirt1 inhibitor (EX-527) after KA-SE, and examined for epileptogenesis using continuous digital video-EEG. Sirt1 activity, measured using chromatin immunoprecipitation for Sirt1 binding at a target gene, increased rapidly after SE. Post hoc infusion of the Sirt1 inhibitor prevented Sirt1-mediated repression of a target gene. Blocking Sirt1 activity transiently after KA-SE did not significantly influence the time- course and all of the parameters of epilepsy development. Specifically, latency to first seizure and seizure number, duration, and severity (using the Racine scale and EEG measures) as well as the frequency and duration of interictal spike series, were all unchanged. KA-SE provoked a robust inflammatory response and modest cell loss, yet neither was altered by blocking Sirt1. In conclusion, blocking Sirt1 activity after KA-SE does not abrogate epilepsy development, suggesting that the mechanisms of such acquired epileptogenesis are independent of Sirt1 function.
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Affiliation(s)
- Alicia M. Hall
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Gary P. Brennan
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, California 92697
| | - Tiffany M. Nguyen
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Akanksha Singh-Taylor
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Hyun-Seung Mun
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Mary J. Sargious
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
| | - Tallie Z. Baram
- Department of Pediatrics, University of California, Irvine, Irvine, California 92697
- Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, California 92697
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23
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Holmes GL, Noebels JL. The Epilepsy Spectrum: Targeting Future Research Challenges. Cold Spring Harb Perspect Med 2016; 6:6/7/a028043. [PMID: 27371672 DOI: 10.1101/cshperspect.a028043] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
There have been tremendous recent advances in our understanding of the biological underpinnings of epilepsy and associated comorbidities that justify its representation as a spectrum disorder. Advances in genetics, electrophysiology, and neuroimaging have greatly improved our ability to differentiate, diagnose, and treat individuals with epilepsy. However, we have made little overall progress in preventing epilepsy, and the number of patients who are cured remains small. Likewise, the comorbidities of epilepsy are often underdiagnosed or not adequately treated. In this article, we suggest a few areas in which additional research will likely pay big dividends for patients and their families.
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Affiliation(s)
- Gregory L Holmes
- Department of Neurological Sciences, University of Vermont College of Medicine, Burlington, Vermont 05405
| | - Jeffrey L Noebels
- Developmental Neurogenetics Laboratory, Departments of Neurology, Neuroscience, and Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
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24
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Feng B, Tang Y, Chen B, Xu C, Wang Y, Dai Y, Wu D, Zhu J, Wang S, Zhou Y, Shi L, Hu W, Zhang X, Chen Z. Transient increase of interleukin-1β after prolonged febrile seizures promotes adult epileptogenesis through long-lasting upregulating endocannabinoid signaling. Sci Rep 2016; 6:21931. [PMID: 26902320 PMCID: PMC4763292 DOI: 10.1038/srep21931] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 02/03/2016] [Indexed: 01/18/2023] Open
Abstract
It remains unclear how infantile febrile seizures (FS) enhance adult seizure susceptibility. Here we showed that the transient increase of interleukin-1β (IL-1β) after prolonged FS promoted adult seizure susceptibility, which was blocked by interleukin-1 receptor antagonist (IL-1Ra) within a critical time window. Postnatal administered IL-1β alone mimicked the effect of FS on adult seizure susceptibility. IL-1R1 knockout mice were not susceptible to adult seizure after prolonged FS or IL-1β treatment. Prolonged FS or early-life IL-1β treatment increased the expression of cannabinoid type 1 receptor (CB1R) for over 50 days, which was blocked by IL-1Ra or was absent in IL-1R1 knockout mice. CB1R antagonist, knockdown and endocannabinoid synthesis inhibitor abolished FS or IL-1β-enhanced seizure susceptibility. Thus, this work identifies a pathogenic role of postnatal IL-1β/IL-1R1 pathway and subsequent prolonged prominent increase of endocannabinoid signaling in adult seizure susceptibility following prolonged FS, and highlights IL-1R1 as a potential therapeutic target for preventing the development of epilepsy after infantile FS.
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Affiliation(s)
- Bo Feng
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China
| | - Yangshun Tang
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China
| | - Bin Chen
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China
| | - Cenglin Xu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China
| | - Yi Wang
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China
| | - Yunjian Dai
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China
| | - Dengchang Wu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China.,Department of Neurology, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, Zhejiang University, China
| | - Junmin Zhu
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, Zhejiang University, China
| | - Shuang Wang
- Epilepsy Center, Department of Neurology, Second Affiliated Hospital, Zhejiang University, China
| | - Yudong Zhou
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China
| | - Liyun Shi
- Department of Basic Medical Science, Hangzhou Normal University, Hangzhou, China
| | - Weiwei Hu
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China
| | - Xia Zhang
- University of Ottawa Institute of Mental Health Research at the Royal, Department of Psychiatry, and Department of Cellular and Molecular Medicine, Ottawa K1Z 7K4, Canada
| | - Zhong Chen
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, 310058, China.,Department of Neurology, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, First Affiliated Hospital, Zhejiang University, China.,Epilepsy Center, Department of Neurology, Second Affiliated Hospital, Zhejiang University, China
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25
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Löscher W, Hirsch LJ, Schmidt D. The enigma of the latent period in the development of symptomatic acquired epilepsy - Traditional view versus new concepts. Epilepsy Behav 2015; 52:78-92. [PMID: 26409135 DOI: 10.1016/j.yebeh.2015.08.037] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 08/30/2015] [Indexed: 01/21/2023]
Abstract
A widely accepted hypothesis holds that there is a seizure-free, pre-epileptic state, termed the "latent period", between a brain insult, such as traumatic brain injury or stroke, and the onset of symptomatic epilepsy, during which a cascade of structural, molecular, and functional alterations gradually mediates the process of epileptogenesis. This review, based on recent data from both animal models and patients with different types of brain injury, proposes that epileptogenesis and often subclinical epilepsy can start immediately after brain injury without any appreciable latent period. Even though the latent period has traditionally been the cornerstone concept representing epileptogenesis, we suggest that the evidence for the existence of a latent period is spotty both for animal models and human epilepsy. Knowing whether a latent period exists or not is important for our understanding of epileptogenesis and for the discovery and the trial design of antiepileptogenic agents. The development of antiepileptogenic treatments to prevent epilepsy in patients at risk from a brain insult is a major unmet clinical need.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, 30559 Hannover, Germany; Center for Systems Neuroscience, 30559 Hannover, Germany.
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26
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Disruption of Fgf13 causes synaptic excitatory-inhibitory imbalance and genetic epilepsy and febrile seizures plus. J Neurosci 2015; 35:8866-81. [PMID: 26063919 DOI: 10.1523/jneurosci.3470-14.2015] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
We identified a family in which a translocation between chromosomes X and 14 was associated with cognitive impairment and a complex genetic disorder termed "Genetic Epilepsy and Febrile Seizures Plus" (GEFS(+)). We demonstrate that the breakpoint on the X chromosome disrupted a gene that encodes an auxiliary protein of voltage-gated Na(+) channels, fibroblast growth factor 13 (Fgf13). Female mice in which one Fgf13 allele was deleted exhibited hyperthermia-induced seizures and epilepsy. Anatomic studies revealed expression of Fgf13 mRNA in both excitatory and inhibitory neurons of hippocampus. Electrophysiological recordings revealed decreased inhibitory and increased excitatory synaptic inputs in hippocampal neurons of Fgf13 mutants. We speculate that reduced expression of Fgf13 impairs excitability of inhibitory interneurons, resulting in enhanced excitability within local circuits of hippocampus and the clinical phenotype of epilepsy. These findings reveal a novel cause of this syndrome and underscore the powerful role of FGF13 in control of neuronal excitability.
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27
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Eun BL, Abraham J, Mlsna L, Kim MJ, Koh S. Lipopolysaccharide potentiates hyperthermia-induced seizures. Brain Behav 2015; 5:e00348. [PMID: 26357586 PMCID: PMC4559014 DOI: 10.1002/brb3.348] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 03/25/2015] [Accepted: 04/05/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Prolonged febrile seizures (FS) have both acute and long-lasting effects on the developing brain. Because FS are often associated with peripheral infection, we aimed to develop a preclinical model of FS that simulates fever and immune activation in order to facilitate the implementation of targeted therapy after prolonged FS in young children. METHODS The innate immune activator lipopolysaccharide (LPS) was administered to postnatal day 14 rat (200 μg/kg) and mouse (100 μg/kg) pups 2-2.5 h prior to hyperthermic seizures (HT) induced by hair dryer or heat lamp. To determine whether simulation of infection enhances neuronal excitability, latency to seizure onset, threshold temperature and total number of seizures were quantified. Behavioral seizures were correlated with electroencephalographic changes in rat pups. Seizure-induced proinflammatory cytokine production was assessed in blood samples at various time points after HT. Seizure-induced microglia activation in the hippocampus was quantified using Cx3cr1(GFP/+) mice. RESULTS Lipopolysaccharide priming increased susceptibility of rats and mice to hyperthemic seizures and enhanced seizure-induced proinflammatory cytokine production and microglial activation. CONCLUSIONS Peripheral inflammation appears to work synergistically with hyperthermia to potentiate seizures and to exacerbate seizure-induced immune responses. By simulating fever, a regulated increase in body temperature from an immune challenge, we developed a more clinically relevant animal model of prolonged FS.
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Affiliation(s)
- Baik-Lin Eun
- Department of Pediatrics, Korea University College of Medicine Seoul, Korea
| | - Jayne Abraham
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, Illinois
| | - Lauren Mlsna
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, Illinois
| | - Min Jung Kim
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, Illinois
| | - Sookyong Koh
- Department of Pediatrics, Ann and Robert H. Lurie Children's Hospital of Chicago Stanley Manne Children's Research Institute, Northwestern University Feinberg School of Medicine Chicago, Illinois
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Chentouf A, Dahdouh A, Guipponi M, Oubaiche ML, Chaouch M, Hamamy H, Antonarakis SE. Familial epilepsy in Algeria: Clinical features and inheritance profiles. Seizure 2015; 31:12-8. [PMID: 26362371 DOI: 10.1016/j.seizure.2015.06.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 06/17/2015] [Accepted: 06/25/2015] [Indexed: 01/14/2023] Open
Abstract
PURPOSE To document the clinical characteristics and inheritance pattern of epilepsy in multigeneration Algerian families. METHODS Affected members from extended families with familial epilepsy were assessed at the University Hospital of Oran in Algeria. Available medical records, neurological examination, electroencephalography and imaging data were reviewed. The epilepsy type was classified according to the criteria of the International League Against Epilepsy and modes of inheritance were deduced from pedigree analysis. RESULTS The study population included 40 probands; 23 male (57.5%) and 17 female subjects (42.5%). The mean age of seizure onset was 9.5 ± 6.1 years. According to seizure onset, 16 patients (40%) had focal seizures and 20 (50%) had generalized seizures. Seizure control was achieved for two patients (5%) for 10 years, while 28 (70%) were seizure-free for 3 months. Eleven patients (27.5%) had prior febrile seizures, 12 were diagnosed with psychiatric disorders and four families had syndromic epilepsy. The consanguinity rate among parents of affected was 50% with phenotypic concordance observed in 25 families (62.5%). Pedigree analysis suggested autosomal dominant (AD) inheritance with or without reduced penetrance in 18 families (45%), probable autosomal recessive (AR) inheritance in 14 families (35%), and an X-linked recessive inheritance in one family. CONCLUSION This study reveals large Algerian families with multigenerational inheritance of epilepsy. Molecular testing such as exome sequencing would clarify the genetic basis of epilepsy in some of our families.
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Affiliation(s)
- Amina Chentouf
- Department of Neurology, University Hospital of Oran, Algeria.
| | - Aïcha Dahdouh
- Department of Psychiatry, University Hospital of Oran, Oran, Algeria
| | - Michel Guipponi
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland; Department of Genetic Medicine and Laboratory, University Hospitals of Geneva, Geneva, Switzerland
| | | | - Malika Chaouch
- Department of Neurology, Benaknoun University Hospital, Algiers, Algeria
| | - Hanan Hamamy
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
| | - Stylianos E Antonarakis
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland; Department of Genetic Medicine and Laboratory, University Hospitals of Geneva, Geneva, Switzerland; Institute of Genetics and Genomics in Geneva (iGE3), Geneva, Switzerland
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Stafstrom CE, Carmant L. Seizures and epilepsy: an overview for neuroscientists. Cold Spring Harb Perspect Med 2015; 5:5/6/a022426. [PMID: 26033084 DOI: 10.1101/cshperspect.a022426] [Citation(s) in RCA: 386] [Impact Index Per Article: 42.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Epilepsy is one of the most common and disabling neurologic conditions, yet we have an incomplete understanding of the detailed pathophysiology and, thus, treatment rationale for much of epilepsy. This article reviews the clinical aspects of seizures and epilepsy with the goal of providing neuroscientists an introduction to aspects that might be amenable to scientific investigation. Seizures and epilepsy are defined, diagnostic methods are reviewed, various clinical syndromes are discussed, and aspects of differential diagnosis, treatment, and prognosis are considered to enable neuroscientists to formulate basic and translational research questions.
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Affiliation(s)
- Carl E Stafstrom
- Division of Pediatric Neurology, Departments of Neurology and Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21287
| | - Lionel Carmant
- Division of Neurology, Department of Pediatrics, Sainte-Justine Hospital, Universite Montreal, Montreal, Quebec H3T 1C5, Canada
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Moreira-Filho CA, Bando SY, Bertonha FB, Iamashita P, Silva FN, Costa LDF, Silva AV, Castro LHM, Wen HT. Community structure analysis of transcriptional networks reveals distinct molecular pathways for early- and late-onset temporal lobe epilepsy with childhood febrile seizures. PLoS One 2015; 10:e0128174. [PMID: 26011637 PMCID: PMC4444281 DOI: 10.1371/journal.pone.0128174] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 04/24/2015] [Indexed: 12/21/2022] Open
Abstract
Age at epilepsy onset has a broad impact on brain plasticity and epilepsy pathomechanisms. Prolonged febrile seizures in early childhood (FS) constitute an initial precipitating insult (IPI) commonly associated with mesial temporal lobe epilepsy (MTLE). FS-MTLE patients may have early disease onset, i.e. just after the IPI, in early childhood, or late-onset, ranging from mid-adolescence to early adult life. The mechanisms governing early (E) or late (L) disease onset are largely unknown. In order to unveil the molecular pathways underlying E and L subtypes of FS-MTLE we investigated global gene expression in hippocampal CA3 explants of FS-MTLE patients submitted to hippocampectomy. Gene coexpression networks (GCNs) were obtained for the E and L patient groups. A network-based approach for GCN analysis was employed allowing: i) the visualization and analysis of differentially expressed (DE) and complete (CO) - all valid GO annotated transcripts - GCNs for the E and L groups; ii) the study of interactions between all the system's constituents based on community detection and coarse-grained community structure methods. We found that the E-DE communities with strongest connection weights harbor highly connected genes mainly related to neural excitability and febrile seizures, whereas in L-DE communities these genes are not only involved in network excitability but also playing roles in other epilepsy-related processes. Inversely, in E-CO the strongly connected communities are related to compensatory pathways (seizure inhibition, neuronal survival and responses to stress conditions) while in L-CO these communities harbor several genes related to pro-epileptic effects, seizure-related mechanisms and vulnerability to epilepsy. These results fit the concept, based on fMRI and behavioral studies, that early onset epilepsies, although impacting more severely the hippocampus, are associated to compensatory mechanisms, while in late MTLE development the brain is less able to generate adaptive mechanisms, what has implications for epilepsy management and drug discovery.
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Affiliation(s)
| | - Silvia Yumi Bando
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
| | - Fernanda Bernardi Bertonha
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
| | - Priscila Iamashita
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, SP, Brazil
| | | | | | | | - Luiz Henrique Martins Castro
- Department of Neurology, FMUSP, São Paulo, SP, Brazil
- Clinical Neurology Division, Hospital das Clínicas, FMUSP, São Paulo, SP, Brazil
| | - Hung-Tzu Wen
- Epilepsy Surgery Group, Hospital das Clínicas, FMUSP, São Paulo, SP, Brazil
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Consanguinity and epilepsy in Oran, Algeria: A case-control study. Epilepsy Res 2015; 111:10-7. [PMID: 25769368 DOI: 10.1016/j.eplepsyres.2014.12.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 12/27/2014] [Accepted: 12/30/2014] [Indexed: 01/23/2023]
Abstract
PURPOSE The goal of this case-control study was to identify the significance of consanguinity and other risk factors for epilepsy in Oran, Algeria. METHODS Unrelated epileptic patients upwards of 16 years, who attended the Neurology Department between October 2013 and March 2014 were included in the study. Controls, matched for age and sex, were selected among non-epileptic patients attending the same department during the same period. The risk factors evaluated were: consanguinity, family history of epilepsy, perinatal complications, infection of the central nervous system, mental retardation, neurological impairment, history of febrile seizures, severe head trauma, cerebrovascular diseases, and addiction. RESULTS 101 cases and 202 controls participated in the study. Multivariate logistic regression identified five factors significantly associated with epilepsy: first-degree of consanguinity (odds ratio (OR)=2.15), history of epilepsy in first-degree relatives (OR=4.03), antecedent of febrile seizures (OR=5.38), severe head injury (OR=2.94) and mental retardation (OR=9.32). CONCLUSION Consanguinity, family history of epilepsy, history of febrile seizures, severe head trauma and mental retardation are risk factors for epilepsy. The implementation of a strategy for prevention and awareness of the impact of consanguineous marriages as well as genetic counseling for couples with a family history of epilepsy are needed.
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32
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Emsley HC, Appleton RE, Whitmore CL, Jury F, Lamb JA, Martin JE, Ollier WE, de la Morandière KP, Southern KW, Allan SM. Variations in inflammation-related genes may be associated with childhood febrile seizure susceptibility. Seizure 2014; 23:457-61. [DOI: 10.1016/j.seizure.2014.03.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 03/04/2014] [Accepted: 03/06/2014] [Indexed: 11/24/2022] Open
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Abstract
Few would experience greater benefit from the development of biomarkers than those who suffer from epilepsy. Both the timing of individual seizures and the overall course of the disease are highly unpredictable, and the associated morbidity is considerable. Thus, there is an urgent need to develop biomarkers that can predict the progression of epilepsy and treatment response. Doing so may also shed light on the mechanisms of epileptogenesis and pharmacoresistance, which remain elusive despite decades of study. However, recent advances suggest the possible identification of circulating epilepsy biomarkers – accessible in blood, cerebrospinal fluid or urine. In this review, we focus on advances in several areas: neuroimmunology and inflammation; neurological viral infection; exemplary pediatric syndromes; and the genetics of pharmacoresistance, as relevant to epilepsy. These are fertile areas of study with great potential to yield accessible epilepsy biomarkers.
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Affiliation(s)
- Manu Hegde
- UCSF Epilepsy Center, Department of Neurology, University of California, San Francisco, 521 Parnassus Avenue C-440, San Francisco, CA 94143-0138, USA
- Epilepsy Center of Excellence, San Francisco Veterans Affairs Medical Center, 4150 Clement Street, 127E, San Francisco, CA 94121, USA
| | - Daniel H Lowenstein
- UCSF Epilepsy Center, Department of Neurology, University of California, San Francisco, 521 Parnassus Avenue C-440, San Francisco, CA 94143-0138, USA
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Lewis DV, Shinnar S, Hesdorffer DC, Bagiella E, Bello JA, Chan S, Xu Y, MacFall J, Gomes WA, Moshé SL, Mathern GW, Pellock JM, Nordli DR, Frank LM, Provenzale J, Shinnar RC, Epstein LG, Masur D, Litherland C, Sun S. Hippocampal sclerosis after febrile status epilepticus: the FEBSTAT study. Ann Neurol 2014; 75:178-85. [PMID: 24318290 DOI: 10.1002/ana.24081] [Citation(s) in RCA: 164] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Revised: 10/30/2013] [Accepted: 11/18/2013] [Indexed: 12/11/2022]
Abstract
OBJECTIVE Whether febrile status epilepticus (FSE) produces hippocampal sclerosis (HS) and temporal lobe epilepsy (TLE) has long been debated. Our objective is to determine whether FSE produces acute hippocampal injury that evolves to HS. METHODS FEBSTAT and 2 affiliated studies prospectively recruited 226 children aged 1 month to 6 years with FSE and controls with simple febrile seizures. All had acute magnetic resonance imaging (MRI), and follow-up MRI was obtained approximately 1 year later in the majority. Visual interpretation by 2 neuroradiologists informed only of subject age was augmented by hippocampal volumetrics, analysis of the intrahippocampal distribution of T2 signal, and apparent diffusion coefficients. RESULTS Hippocampal T2 hyperintensity, maximum in Sommer's sector, occurred acutely after FSE in 22 of 226 children in association with increased volume. Follow-up MRI obtained on 14 of the 22 with acute T2 hyperintensity showed HS in 10 and reduced hippocampal volume in 12. In contrast, follow-up of 116 children without acute hyperintensity showed abnormal T2 signal in only 1 (following another episode of FSE). Furthermore, compared to controls with simple febrile seizures, FSE subjects with normal acute MRI had abnormally low right to left hippocampal volume ratios, smaller hippocampi initially, and reduced hippocampal growth. INTERPRETATION Hippocampal T2 hyperintensity after FSE represents acute injury often evolving to a radiological appearance of HS after 1 year. Furthermore, impaired growth of normal-appearing hippocampi after FSE suggests subtle injury even in the absence of T2 hyperintensity. Longer follow-up is needed to determine the relationship of these findings to TLE.
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Affiliation(s)
- Darrell V Lewis
- Department of Pediatrics (Neurology), Duke University Medical Center, Durham, NC
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Marchi N, Granata T, Janigro D. Inflammatory pathways of seizure disorders. Trends Neurosci 2014; 37:55-65. [PMID: 24355813 PMCID: PMC3977596 DOI: 10.1016/j.tins.2013.11.002] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 11/17/2013] [Accepted: 11/18/2013] [Indexed: 12/17/2022]
Abstract
Epilepsy refers to a cluster of neurological diseases characterized by seizures. Although many forms of epilepsy have a well-defined immune etiology, in other forms of epilepsy an altered immune response is only suspected. In general, the hypothesis that inflammation contributes to seizures is supported by experimental results. Additionally, antiepileptic maneuvers may act as immunomodulators and anti-inflammatory therapies can treat seizures. Triggers of seizure include a bidirectional communication between the nervous system and organs of immunity. Thus, a crucial cellular interface protecting from immunological seizures is the blood-brain barrier (BBB). Here, we summarize recent advances in the understanding and treatment of epileptic seizures that derive from a non-neurocentric viewpoint and suggest key avenues for future research.
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Affiliation(s)
- Nicola Marchi
- Department of Molecular Medicine, Cerebrovascular Research, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA; Department of Neurobiology, Institute of Functional Genomics, Centre National de la Recherche Scientifique, Montpellier, France
| | | | - Damir Janigro
- Department of Molecular Medicine, Cerebrovascular Research, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA; Department of Neurological Surgery, Cerebrovascular Research, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA.
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Nakamura Y, Shi X, Numata T, Mori Y, Inoue R, Lossin C, Baram TZ, Hirose S. Novel HCN2 mutation contributes to febrile seizures by shifting the channel's kinetics in a temperature-dependent manner. PLoS One 2013; 8:e80376. [PMID: 24324597 PMCID: PMC3851455 DOI: 10.1371/journal.pone.0080376] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Accepted: 10/02/2013] [Indexed: 12/27/2022] Open
Abstract
Hyperpolarization-activated cyclic nucleotide-gated (HCN) channel-mediated currents, known as I h, are involved in the control of rhythmic activity in neuronal circuits and in determining neuronal properties including the resting membrane potential. Recent studies have shown that HCN channels play a role in seizure susceptibility and in absence and limbic epilepsy including temporal lobe epilepsy following long febrile seizures (FS). This study focused on the potential contributions of abnormalities in the HCN2 isoform and their role in FS. A novel heterozygous missense mutation in HCN2 exon 1 leading to p.S126L was identified in two unrelated patients with FS. The mutation was inherited from the mother who had suffered from FS in a pedigree. To determine the effect of this substitution we conducted whole-cell patch clamp electrophysiology. We found that mutant channels had elevated sensitivity to temperature. More specifically, they displayed faster kinetics at higher temperature. Kinetic shift by change of temperature sensitivity rather than the shift of voltage dependence led to increased availability of I h in conditions promoting FS. Responses to cyclic AMP did not differ between wildtype and mutant channels. Thus, mutant HCN2 channels cause significant cAMP-independent enhanced availability of I h during high temperatures, which may contribute to hyperthermia-induced neuronal hyperexcitability in some individuals with FS.
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Affiliation(s)
- Yuki Nakamura
- Department of Pediatrics, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
- The Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka, Japan
| | - Xiuyu Shi
- The Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka, Japan
- Department of Pediatrics, Chinese PLA General Hospital, Beijing, China
| | - Tomohiro Numata
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Yasuo Mori
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Ryuji Inoue
- Department of Physiology, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
| | - Christoph Lossin
- Department of Neurology, School of Medicine University of California Davis, Sacramento, California, United States of America
| | - Tallie Z. Baram
- Departments of Anatomy & Neurobiology, Pediatrics, and Neurology, University of California Irvine, Irvine, California, United States of America
| | - Shinichi Hirose
- Department of Pediatrics, Faculty of Medicine, Fukuoka University, Fukuoka, Japan
- The Research Institute for the Molecular Pathomechanisms of Epilepsy, Fukuoka University, Fukuoka, Japan
- * E-mail:
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Bando SY, Silva FN, Costa LDF, Silva AV, Pimentel-Silva LR, Castro LHM, Wen HT, Amaro E, Moreira-Filho CA. Complex network analysis of CA3 transcriptome reveals pathogenic and compensatory pathways in refractory temporal lobe epilepsy. PLoS One 2013; 8:e79913. [PMID: 24278214 PMCID: PMC3836787 DOI: 10.1371/journal.pone.0079913] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Accepted: 09/25/2013] [Indexed: 12/21/2022] Open
Abstract
We previously described - studying transcriptional signatures of hippocampal CA3 explants - that febrile (FS) and afebrile (NFS) forms of refractory mesial temporal lobe epilepsy constitute two distinct genomic phenotypes. That network analysis was based on a limited number (hundreds) of differentially expressed genes (DE networks) among a large set of valid transcripts (close to two tens of thousands). Here we developed a methodology for complex network visualization (3D) and analysis that allows the categorization of network nodes according to distinct hierarchical levels of gene-gene connections (node degree) and of interconnection between node neighbors (concentric node degree). Hubs are highly connected nodes, VIPs have low node degree but connect only with hubs, and high-hubs have VIP status and high overall number of connections. Studying the whole set of CA3 valid transcripts we: i) obtained complete transcriptional networks (CO) for FS and NFS phenotypic groups; ii) examined how CO and DE networks are related; iii) characterized genomic and molecular mechanisms underlying FS and NFS phenotypes, identifying potential novel targets for therapeutic interventions. We found that: i) DE hubs and VIPs are evenly distributed inside the CO networks; ii) most DE hubs and VIPs are related to synaptic transmission and neuronal excitability whereas most CO hubs, VIPs and high hubs are related to neuronal differentiation, homeostasis and neuroprotection, indicating compensatory mechanisms. Complex network visualization and analysis is a useful tool for systems biology approaches to multifactorial diseases. Network centrality observed for hubs, VIPs and high hubs of CO networks, is consistent with the network disease model, where a group of nodes whose perturbation leads to a disease phenotype occupies a central position in the network. Conceivably, the chance for exerting therapeutic effects through the modulation of particular genes will be higher if these genes are highly interconnected in transcriptional networks.
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Affiliation(s)
- Silvia Yumi Bando
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, São Paulo, Brazil
| | | | | | - Alexandre V. Silva
- Department of Biosciences, Universidade Federal de São Paulo, Santos, São Paulo, Brazil
| | | | - Luiz HM. Castro
- Clinical Neurology Division, Hospital das Clínicas da FMUSP, São Paulo, São Paulo, Brazil
| | - Hung-Tzu Wen
- Epilepsy Surgery Group, Hospital das Clínicas da FMUSP, São Paulo, São Paulo, Brazil
| | - Edson Amaro
- Department of Radiology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, São Paulo, Brazil
| | - Carlos Alberto Moreira-Filho
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, São Paulo, Brazil
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Pavlidou E, Panteliadis C. Prognostic factors for subsequent epilepsy in children with febrile seizures. Epilepsia 2013; 54:2101-7. [PMID: 24304433 DOI: 10.1111/epi.12429] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/20/2013] [Indexed: 10/26/2022]
Abstract
OBJECTIVE Epilepsy following febrile seizures (FS) has been estimated between 2% and 7%. It concerns a prospective study in a large sample of children with a long-term follow-up. The aim of this study is to identify the prognostic factors that can lead children with FS to epilepsy. METHODS Children with a first episode of FS were included. We gathered information about prenatal and perinatal history, family history of FS and epilepsy in first- and second degree relatives, age at the time of the initial FS, dates of FS recurrences, focality, duration of the FS and recurrent episodes within the same febrile illness, height and duration of fever prior to the seizure, cause of the fever, and frequency of febrile illnesses. Patients were seen every 4-6 months and also at each recurrence. KEY FINDINGS A group of 560 children with a first FS met all entry criteria. Epilepsy was recorded at 5.4%. Statistical analysis was performed between children with epilepsy and those with no afebrile seizure. We analyzed FS recurrences in accordance with the occurrence of epilepsy. From the third FS recurrence and beyond, only focality continued to have prognostic value. SIGNIFICANCE Main prognostic factors for the development of epilepsy after FS are: (1) complex FS that increased the risk for epilepsy 3.6 times, (2) age at onset of FS beyond the third year of life that raised the risk 3.8 times, (3) positive family history of epilepsy 7.3 times, and (4) multiple episodes of FS about 10 times. Focality at the first and the second FS recurrence increased the risk of epilepsy about 9.7 and 11.7 times, respectively. Focality was the only factor that continued to be significant in further FS recurrences. A prognostic profile of each child with FS would be very useful for the follow-up of these children.
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Affiliation(s)
- Efterpi Pavlidou
- Pediatric Neurology Department, A.H.E.P.A Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Reddy DS. Role of hormones and neurosteroids in epileptogenesis. Front Cell Neurosci 2013; 7:115. [PMID: 23914154 PMCID: PMC3728472 DOI: 10.3389/fncel.2013.00115] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Accepted: 07/01/2013] [Indexed: 12/03/2022] Open
Abstract
This article describes the emerging evidence of hormonal influence on epileptogenesis, which is a process whereby a brain becomes progressively epileptic due to an initial precipitating event of diverse origin such as brain injury, stroke, infection, or prolonged seizures. The molecular mechanisms underlying the development of epilepsy are poorly understood. Neuroinflammation and neurodegeneration appear to trigger epileptogenesis. There is an intense search for drugs that truly prevent the development of epilepsy in people at risk. Hormones play an important role in children and adults with epilepsy. Corticosteroids, progesterone, estrogens, and neurosteroids have been shown to affect seizure activity in animal models and in clinical studies. However, the impact of hormones on epileptogenesis has not been investigated widely. There is emerging new evidence that progesterone, neurosteroids, and endogenous hormones may play a role in regulating the epileptogenesis. Corticosterone has excitatory effects and triggers epileptogenesis in animal models. Progesterone has disease-modifying activity in epileptogenic models. The antiepileptogenic effect of progesterone has been attributed to its conversion to neurosteroids, which binds to GABA-A receptors and enhances phasic and tonic inhibition in the brain. Neurosteroids are robust anticonvulsants. There is pilot evidence that neurosteroids may have antiepileptogenic properties. Future studies may generate new insight on the disease-modifying potential of hormonal agents and neurosteroids in epileptogenesis.
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Affiliation(s)
- Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center Bryan, TX, USA
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Kandratavicius L, Rosa-Neto P, Monteiro MR, Guiot MC, Assirati JA, Carlotti CG, Kobayashi E, Leite JP. Distinct increased metabotropic glutamate receptor type 5 (mGluR5) in temporal lobe epilepsy with and without hippocampal sclerosis. Hippocampus 2013; 23:1212-30. [PMID: 23804486 PMCID: PMC4165311 DOI: 10.1002/hipo.22160] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/31/2013] [Indexed: 12/04/2022]
Abstract
Metabotropic glutamate receptor type 5 (mGluR5) upregulation in temporal lobe epilepsy (TLE) and the correlation of its expression with features of hippocampal sclerosis (HS) remains unclear. Here we characterized mGluR5 immunoreactivity in hippocampus, entorhinal cortex (EC), and subiculum of TLE specimens with confirmed HS, with neocortical TLE (non-HS) and necropsy controls. We correlated mGluR5 immunoreactivity with neuronal density, mossy fiber sprouting, astrogliosis (GFAP), and dendritic alterations (MAP2). TLE specimens showed increased mGluR5 expression, which was most pronounced in the EC, subiculum, CA2, and dentate gyrus outer molecular layer. Increased mGluR5 expression was seen in hippocampal head and body segments and was independent of neuronal density, astrogliosis, or dendritic alterations. Positive correlation between mGluR5 expression with mossy fiber sprouting and with MAP2 in CA3 and CA1 was found only in HS specimens. Negative correlation between mGluR5 expression with seizure frequency and epilepsy duration was found only in non-HS cases. Specimens from HS patients without previous history of febrile seizure (FS) showed higher mGluR5 and MAP2 expression in CA2. Our study suggests that mGluR5 upregulation is part of a repertoire of post-synaptic adaptations that might control overexcitation and excessive glutamate release rather than a dysfunction that leads to seizure facilitation. That would explain why non-HS cases, on which seizures are likely to originate outside the hippocampal formation, also exhibit upregulated mGluR5. On the other hand, lower mGluR5 expression was related to increased seizure frequency. In addition to its role in hyperexcitability, mGluR5 upregulation could play a role in counterbalance mechanisms along the hyperexcitable circuitry uniquely altered in sclerotic hippocampal formation. Inefficient post-synaptic compensatory morphological (dendritic branching) and glutamatergic (mGluR5 expression) mechanisms in CA2 subfield could potentially underlie the association of FS with HS and TLE. © 2013 Wiley Periodicals, Inc.
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Affiliation(s)
- Ludmyla Kandratavicius
- Department of Neurosciences and Behavior, Ribeirao Preto Medical School, University of Sao PauloBrazil
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill UniversityMontreal, Canada
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, Department of Neurology and Neurosurgery, Douglas Research Institute, McGill UniversityMontreal, Canada
| | - Mariana Raquel Monteiro
- Department of Neurosciences and Behavior, Ribeirao Preto Medical School, University of Sao PauloBrazil
| | - Marie-Christine Guiot
- Department of Pathology, Montreal Neurological Institute, McGill UniversityMontreal, Canada
| | | | | | - Eliane Kobayashi
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill UniversityMontreal, Canada
| | - Joao Pereira Leite
- Department of Neurosciences and Behavior, Ribeirao Preto Medical School, University of Sao PauloBrazil
- *Correspondence to: Joao Pereira Leite, Ribeirao Preto Medical School, Department of Neurosciences and Behavior, University of Sao Paulo, Av Bandeirantes 3900, 14049-900, Ribeirao Preto, SP, Brazil. E-mail:
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Abstract
Epilepsy is a prevalent neurological disorder associated with significant morbidity and mortality, but the only available drug therapies target its symptoms rather than the underlying cause. The process that links brain injury or other predisposing factors to the subsequent emergence of epilepsy is termed epileptogenesis. Substantial research has focused on elucidating the mechanisms of epileptogenesis so as to identify more specific targets for intervention, with the hope of preventing epilepsy before seizures emerge. Recent work has yielded important conceptual advances in this field. We suggest that such insights into the mechanisms of epileptogenesis converge at the level of cortical circuit dysfunction.
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Abstract
The human brain is a tremendously complex and still enigmatic three-dimensional structure, composed of countless interconnected neurons and glia. The temporal evolution of the brain throughout life provides a fourth dimension, one that influences every element of the brain's function in health and disease. This temporal evolution contributes to the probability of seizure generation and to the type and the nature of these seizures. The age-specific properties of the brain also influence the consequences of seizures on neuronal structure and behavior. These, in turn, govern epileptic activity and cognitive and emotional functions, contributing to the diverse consequences of seizures and epilepsy throughout life.
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43
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Marsh ED. Fishing for the mechanisms causing febrile seizures: employing a novel model to uncover the physiological generators of seizures with fever. Exp Neurol 2012. [PMID: 23178581 DOI: 10.1016/j.expneurol.2012.11.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Eric D Marsh
- Division of Neurology, Children's Hospital of Philadelphia and Department of Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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44
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Neuronal injury and cytogenesis after simple febrile seizures in the hippocampal dentate gyrus of juvenile rat. Childs Nerv Syst 2012; 28:1931-6. [PMID: 22661146 DOI: 10.1007/s00381-012-1817-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Accepted: 05/18/2012] [Indexed: 10/28/2022]
Abstract
PURPOSE Although simple febrile seizures are frequently described as harmless, there is evidence which suggests that hippocampal damage may occur after simple febrile seizures. This study aimed to investigate possible neuronal damages as well as alterations in cytogenesis in the hippocampal dentate gyrus following simple febrile seizures. METHODS Simple febrile seizure was modeled by hyperthermia-induced seizures in 22-day-old male rats. The brains were removed 2 or 15 days after hyperthermia in all rats with (n=20) and without (n=10) occurrence of seizures as well as in control animals (n=10). The sections were stained with hematoxylin and eosin to estimate the surface numerical density of dark neurons. Ki-67 immunohistochemistry was performed to evaluate changes of cytogenesis following simple febrile seizures. RESULTS Hyperthermia induced behavioral seizure activities in 67 % of the rats. The numerical densities of dark neurons as well as the mean Ki-67 index (the fraction of Ki-67-positive cells) were significantly increased in dentate gyrus after induction of seizures by hyperthermia compared to both controls and rats without seizure after hyperthermia. Both the seizure duration and intensity were correlated significantly with numerical densities of dark neurons (but not with Ki-67 index). CONCLUSION The data indicate that simple febrile seizures can cause neuronal damages and enhancement of cytogenesis in the hippocampal dentate gyrus, which were still visible for at least 2 weeks. These findings also suggest the correlation of febrile seizure intensity and duration with neuronal damage.
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45
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Epstein LG, Shinnar S, Hesdorffer DC, Nordli DR, Hamidullah A, Benn EKT, Pellock JM, Frank LM, Lewis DV, Moshe SL, Shinnar RC, Sun S. Human herpesvirus 6 and 7 in febrile status epilepticus: the FEBSTAT study. Epilepsia 2012; 53:1481-8. [PMID: 22954016 DOI: 10.1111/j.1528-1167.2012.03542.x] [Citation(s) in RCA: 101] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE In a prospective study, Consequences of Prolonged Febrile Seizures in Childhood (FEBSTAT), we determined the frequency of human herpesvirus (HHV)-6 and HHV-7 infection as a cause of febrile status epilepticus (FSE). METHODS Children ages 1 month to 5 years presenting with FSE were enrolled within 72 h and received a comprehensive assessment including specimens for HHV-6 and HHV-7. The presence of HHV-6A, HHV-6B, or HHV-7 DNA and RNA (amplified across a spliced junction) determined using quantitative polymerase chain reaction (qPCR) at baseline indicated viremia. Antibody titers to HHV-6 and HHV-7 were used in conjunction with the PCR results to distinguish primary infection from reactivated or prior infection. KEY FINDINGS Of 199 children evaluated, HHV-6 or HHV-7 status could be determined in 169 (84.9%). HHV-6B viremia at baseline was found in 54 children (32.0%), including 38 with primary infection and 16 with reactivated infection. No HHV-6A infections were identified. HHV-7 viremia at baseline was observed in 12 children (7.1%), including eight with primary infection and four with reactivated infection. Two subjects had HHV-6/HHV-7 primary coinfection at baseline. There were no differences in age, characteristics of illness or fever, seizure phenomenology or the proportion of acute EEG or imaging abnormalities in children presenting with FSE with or without HHV infection. SIGNIFICANCE HHV-6B infection is commonly associated with FSE. HHV-7 infection is less frequently associated with FSE. Together, they account for one third of FSE, a condition associated with an increased risk of both hippocampal injury and subsequent temporal lobe epilepsy.
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Affiliation(s)
- Leon G Epstein
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University and Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA.
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46
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Atypical febrile seizures, mesial temporal lobe epilepsy, and dual pathology. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:342928. [PMID: 22957226 PMCID: PMC3420631 DOI: 10.1155/2012/342928] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2011] [Revised: 02/02/2012] [Accepted: 02/07/2012] [Indexed: 12/02/2022]
Abstract
Febrile seizures occurring in the neonatal period, especially when prolonged, are thought to be involved in the later development of mesial temporal lobe epilepsy (mTLE) in children. The presence of an often undetected, underlying cortical malformation has also been reported to be implicated in the epileptogenesis process following febrile seizures. This paper highlights some of the various animal models of febrile seizures and of cortical malformation and portrays a two-hit model that efficiently mimics these two insults and leads to spontaneous recurrent seizures in adult rats. Potential mechanisms are further proposed to explain how these two insults may each, or together, contribute to network hyperexcitability and epileptogenesis. Finally the clinical relevance of the two-hit model is briefly discussed in light of a therapeutic and preventive approach to mTLE.
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47
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Temporal lobe epilepsy after refractory status epilepticus: an illustrative case and review of the literature. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:209701. [PMID: 22953058 PMCID: PMC3420734 DOI: 10.1155/2012/209701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 01/29/2012] [Indexed: 11/17/2022]
Abstract
New onset refractory status epilepticus (NORSE) is a relatively newly defined disease entity, where otherwise healthy individuals develop unrelenting seizures that do not respond to conventional anticonvulsant therapy and may require months of therapy with anesthetic drugs. We have described a case of NORSE who subsequently developed mesial temporal lobe sclerosis (MTS) and recurrent temporal lobe seizures. We discuss the possible pathophysiological mechanisms by which refractory seizures may contribute to the development of temporal lobe epilepsy (TLE).
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48
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Gomes WA, Shinnar S. Prospects for imaging-related biomarkers of human epileptogenesis: a critical review. Biomark Med 2012; 5:599-606. [PMID: 22003908 DOI: 10.2217/bmm.11.66] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
To facilitate the study of epileptogenesis in humans, noninvasive biomarkers of epileptogenesis are required. No validated biomarker is currently available, but brain imaging techniques provide many attractive candidates. In this article we examine the imaging features of temporal lobe epilepsy, focusing on those that may precede the onset of epilepsy and correlate with epileptogenesis. Hippocampal volumetry and T(2) relaxometry are proposed as candidate biomarkers of epileptogenesis in temporal lobe epilepsy following febrile status epilepticus. Preliminary data suggest that these have promise, and the ongoing Consequences of Prolonged Febrile Seizures in Childhood (FEBSTAT) study will provide more conclusive evidence as to their validity. At this time there are no other clear candidates for imaging-related biomarkers of epileptogenesis in human studies.
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Affiliation(s)
- William A Gomes
- Comprehensive Epilepsy Management Center, Montefiore Medical Center, 111 E. 210th St, Bronx, NY 10467, USA
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49
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de Carvalho Alegro M, Valotta Silva A, Yumi Bando S, de Deus Lopes R, Martins de Castro LH, Hungtsu W, Moreira-Filho CA, Amaro E. Texture analysis of high resolution MRI allows discrimination between febrile and afebrile initial precipitating injury in mesial temporal sclerosis. Magn Reson Med 2012; 68:1647-53. [PMID: 22287318 DOI: 10.1002/mrm.24174] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2011] [Revised: 12/12/2011] [Accepted: 12/29/2011] [Indexed: 01/10/2023]
Abstract
A computational pipeline combining texture analysis and pattern classification algorithms was developed for investigating associations between high-resolution MRI features and histological data. This methodology was tested in the study of dentate gyrus images of sclerotic hippocampi resected from refractory epilepsy patients. Images were acquired using a simple surface coil in a 3.0T MRI scanner. All specimens were subsequently submitted to histological semiquantitative evaluation. The computational pipeline was applied for classifying pixels according to: a) dentate gyrus histological parameters and b) patients' febrile or afebrile initial precipitating insult history. The pipeline results for febrile and afebrile patients achieved 70% classification accuracy, with 78% sensitivity and 80% specificity [area under the reader observer characteristics (ROC) curve: 0.89]. The analysis of the histological data alone was not sufficient to achieve significant power to separate febrile and afebrile groups. Interesting enough, the results from our approach did not show significant correlation with histological parameters (which per se were not enough to classify patient groups). These results showed the potential of adding computational texture analysis together with classification methods for detecting subtle MRI signal differences, a method sufficient to provide good clinical classification. A wide range of applications of this pipeline can also be used in other areas of medical imaging.
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Affiliation(s)
- Maryana de Carvalho Alegro
- Brain Institute/Dep. Radiology-Hospital Israelita Albert Einstein, Integrated Systems Laboratory, Escola Politécnica da Universidade de São Paulo, São Paulo, SP, Brazil
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50
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Bando SY, Alegro MC, Amaro E, Silva AV, Castro LHM, Wen HT, Lima LDA, Brentani H, Moreira-Filho CA. Hippocampal CA3 transcriptome signature correlates with initial precipitating injury in refractory mesial temporal lobe epilepsy. PLoS One 2011; 6:e26268. [PMID: 22022585 PMCID: PMC3194819 DOI: 10.1371/journal.pone.0026268] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 09/23/2011] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Prolonged febrile seizures constitute an initial precipitating injury (IPI) commonly associated with refractory mesial temporal lobe epilepsy (RMTLE). In order to investigate IPI influence on the transcriptional phenotype underlying RMTLE we comparatively analyzed the transcriptomic signatures of CA3 explants surgically obtained from RMTLE patients with (FS) or without (NFS) febrile seizure history. Texture analyses on MRI images of dentate gyrus were conducted in a subset of surgically removed sclerotic hippocampi for identifying IPI-associated histo-radiological alterations. METHODOLOGY/PRINCIPAL FINDINGS DNA microarray analysis revealed that CA3 global gene expression differed significantly between FS and NFS subgroups. An integrative functional genomics methodology was used for characterizing the relations between GO biological processes themes and constructing transcriptional interaction networks defining the FS and NFS transcriptomic signatures and its major gene-gene links (hubs). Co-expression network analysis showed that: i) CA3 transcriptomic profiles differ according to the IPI; ii) FS distinctive hubs are mostly linked to glutamatergic signalization while NFS hubs predominantly involve GABAergic pathways and neurotransmission modulation. Both networks have relevant hubs related to nervous system development, what is consistent with cell genesis activity in the hippocampus of RMTLE patients. Moreover, two candidate genes for therapeutic targeting came out from this analysis: SSTR1, a relevant common hub in febrile and afebrile transcriptomes, and CHRM3, due to its putative role in epilepsy susceptibility development. MRI texture analysis allowed an overall accuracy of 90% for pixels correctly classified as belonging to FS or NFS groups. Histological examination revealed that granule cell loss was significantly higher in FS hippocampi. CONCLUSIONS/SIGNIFICANCE CA3 transcriptional signatures and dentate gyrus morphology fairly correlate with IPI in RMTLE, indicating that FS-RMTLE represents a distinct phenotype. These findings may shed light on the molecular mechanisms underlying refractory epilepsy phenotypes and contribute to the discovery of novel specific drug targets for therapeutic interventions.
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Affiliation(s)
- Silvia Y. Bando
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, São Paulo, Brazil
| | - Maryana C. Alegro
- Laboratory of Integrated Systems, Escola Politécnica da Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Edson Amaro
- Department of Radiology, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, São Paulo, Brazil
| | - Alexandre V. Silva
- Department of Biosciences, Universidade Federal de São Paulo, Santos, São Paulo, Brazil
| | - Luiz H. M. Castro
- Clinical Neurology Division, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Hung-Tzu Wen
- Epilepsy Surgery Group, Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, São Paulo, Brazil
| | - Leandro de A. Lima
- Laboratory of Biotechnology, Hospital do Câncer AC Camargo, São Paulo, São Paulo, Brazil
| | - Helena Brentani
- Department of Psychiatry, Instituto Nacional de Psiquiatria do Desenvolvimento and Laboratório de Investigação Médica 23, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, São Paulo, Brazil
| | - Carlos Alberto Moreira-Filho
- Department of Pediatrics, Faculdade de Medicina da Universidade de São Paulo (FMUSP), São Paulo, São Paulo, Brazil
- * E-mail:
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