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Leung JSC. Febrile Seizures: An Updated Narrative Review for Pediatric Ambulatory Care Providers. Curr Pediatr Rev 2024; 20:43-58. [PMID: 36043723 DOI: 10.2174/1573396318666220829121946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 06/03/2022] [Accepted: 06/21/2022] [Indexed: 11/22/2022]
Abstract
BACKGROUND While generally self-limited, febrile seizures result in significant familial distress. Ambulatory pediatric care providers must be prepared to counsel families on the causes, risk factors, management principles, and prognosis of children with febrile seizures. OBJECTIVE To provide an updated, evidence-based review of febrile seizures focused on the needs of an ambulatory pediatric care provider. METHODS A narrative review of the literature prioritizing landmark articles, metanalyses, longitudinal population longitudinal cohort studies and national level guidelines. RESULTS Febrile seizures are aberrant physiological responses to fever in children caused by complex interactions of cytokine mediated neuroinflammation, environmental triggers, and genetic predisposition. Other than investigations to determine fever etiology, routine bloodwork, lumbar punctures, neuroimaging and electroencephalograms are low yield. The general prognosis is excellent, however, clinicians should be aware of long-term outcomes including: cognitive impairment with non-simple febrile seizures; neuropsychiatric associations; recurrent febrile seizure and epilepsy risk factors; and the association between complex febrile seizures and sudden unexpected death. Children with a high risk of recurrence, complex febrile seizures, limited access to care, or extreme parental anxiety may benefit from intermittent oral diazepam prophylaxis. CONCLUSION Clinicians should consider four management priorities: 1) terminating the seizure; 2) excluding critical differential diagnoses; 3) investigating fever etiology; and 4) providing adequate counselling to families. The clinical approach and prognosis of febrile seizure can be based on subtype. Children with non-simple (i.e. complex or febrile status epilepticus) febrile seizures require closer care than the vast majority of children with simple febrile seizures, who have excellent outcomes.
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Affiliation(s)
- James Sze-Chuck Leung
- Department of Pediatrics, Division of Pediatric Emergency Medicine, McMaster University, Hamilton, Ontario, Canada
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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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Tokumoto S, Nishiyama M, Yamaguchi H, Tomioka K, Ishida Y, Toyoshima D, Kurosawa H, Nozu K, Maruyama A, Tanaka R, Iijima K, Nagase H. Prognostic effects of treatment protocols for febrile convulsive status epilepticus in children. BMC Neurol 2022; 22:77. [PMID: 35247987 PMCID: PMC8897930 DOI: 10.1186/s12883-022-02608-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 02/28/2022] [Indexed: 11/29/2022] Open
Abstract
Background Febrile status epilepticus is the most common form of status epilepticus in children. No previous reports compare the effectiveness of treatment strategies using fosphenytoin (fPHT) or phenobarbital (PB) and those using anesthetics as second-line anti-seizure medication for benzodiazepine-resistant convulsive status epilepticus (CSE). We aimed to examine the outcomes of various treatment strategies for febrile convulsive status epilepticus (FCSE) in a real-world setting while comparing the effects of different treatment protocols and their presence or absence. Methods This was a single-center historical cohort study that was divided into three periods. Patients who presented with febrile convulsive status epilepticus for ≥60 min even after the administration of at least one anticonvulsant were included. During period I (October 2002–December 2006), treatment was performed at the discretion of the attending physician, without a protocol. During period II (January 2007–February 2013), barbiturate coma therapy (BCT) was indicated for FCSE resistant to benzodiazepines. During period III (March 2013–April 2016), BCT was indicated for FCSE resistant to fPHT or PB. Results The rate of electroencephalogram monitoring was lower in period I than period II+III (11.5% vs. 85.7%, p<0.01). Midazolam was administered by continuous infusion more often in period I than period II+III (84.6% vs. 25.0%, p<0.01), whereas fPHT was administered less often in period I than period II+III (0% vs. 27.4%, p<0.01). The rate of poor outcome, which was determined using the Pediatric Cerebral Performance Category scale, was higher in period I than period II+III (23.1% vs. 7.1%, p=0.03). The rate of poor outcome did not differ between periods II and III (4.2% vs. 11.1%, p=0.40). Conclusions While the presence of a treatment protocol for FCSE in children may improve outcomes, a treatment protocol using fPHT or PB may not be associated with better outcomes.
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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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Pavone P, Pappalardo XG, Parano E, Falsaperla R, Marino SD, Fink JK, Ruggieri M. Fever-Associated Seizures or Epilepsy: An Overview of Old and Recent Literature Acquisitions. Front Pediatr 2022; 10:858945. [PMID: 35529330 PMCID: PMC9070101 DOI: 10.3389/fped.2022.858945] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/17/2022] [Indexed: 02/06/2023] Open
Abstract
In addition to central nervous system infections, seizures and fever may occur together in several neurological disorders. Formerly, based on the clinical features and prognostic evolution, the co-association of seizure and fever included classical febrile seizures (FS) divided into simple, complex, and prolonged FS (also called febrile status epilepticus). Later, this group of disorders has been progressively indicated, with a more inclusive term, as "fever-associated seizures or epilepsy" (FASE) that encompasses: (a) FS divided into simple, complex, and prolonged FS; (b) FS plus; (c) severe myoclonic epilepsy in infancy (Dravet syndrome); (d) genetic epilepsy with FS plus; and (e) febrile infection-related epilepsy syndrome (FIRES). Among the FASE disorders, simple FS, the most common and benign condition, is rarely associated with subsequent epileptic seizures. The correlation of FS with epilepsy and other neurological disorders is highly variable. The pathogenesis of FASE is unclear but immunological and genetic factors play a relevant role and the disorders belonging to the FASE group show to have an underlying common clinical, immunological, and genetic pathway. In this study, we have reviewed and analyzed the clinical data of each of the heterogeneous group of disorders belonging to FASE.
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Affiliation(s)
- Piero Pavone
- Unit of Clinical Pediatrics, AOU "Policlinico", PO "G. Rodolico", University of Catania, Catania, Italy
| | - Xena Giada Pappalardo
- Unit of Catania, National Council of Research, Institute for Research and Biomedical Innovation (IRIB), Catania, Italy.,Department of Biomedical and Biotechnological Sciences (BIOMETEC), University of Catania, Catania, Italy
| | - Enrico Parano
- Unit of Catania, National Council of Research, Institute for Research and Biomedical Innovation (IRIB), Catania, Italy
| | - Raffaele Falsaperla
- Unit of Pediatrics, Neonatology and Neonatal Intensive Care, and Pediatric Emergency, AOU "Policlinico", PO "San Marco", University of Catania, Catania, Italy
| | - Simona Domenica Marino
- Unit of Pediatrics, Neonatology and Neonatal Intensive Care, and Pediatric Emergency, AOU "Policlinico", PO "San Marco", University of Catania, Catania, Italy
| | - John Kane Fink
- Department of Neurology and Ann Arbor Veterans Affairs Medical Center, University of Michigan, Ann Arbor, MI, United States
| | - Martino Ruggieri
- Unit of Rare Diseases of the Nervous System in Childhood, Department of Clinical and Experimental Medicine, Section of Pediatrics and Child Neuropsychiatry, University of Catania, AOU "Policlinico", PO "G. Rodolico", Catania, Italy
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Abstract
Introduction Febrile seizure (FS) is the most common cause of convulsion in children. In the present study, we evaluated patients presenting with FS. Methods Eighty-two patients aged between 6-60 months who presented to Mersin City Training and Research Hospital with the first febrile seizure between January 2020 and May 2021 were included in the study. Results Of the 82 patients included in our study, 42 (51,2%) were male and 40 were female (48,8%). Their average age at presentation of first febrile seizure was 21,05 ± 16,22 months. Fever focus was found in 32 patients (39,1%) with upper respiratory tract infection. Epileptic abnormality was observed in the EEG of six patients (7,3%) and antiepileptic medication was started in three of these patients. Conclusions Upper respiratory tract infection, family history of FS, and family history of epilepsy are the main risk factors for the development of FS. Complex FS is a serious risk factor for the development of epilepsy.
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Affiliation(s)
- Mahmut Aslan
- Pediatric Neurology, Mersin City Hospital, Mersin, TUR
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Cokyaman T. Febril nöbetler: Ateş sonrası nöbet zamansal sıralamasının bir önemi var mıdır? FAMILY PRACTICE AND PALLIATIVE CARE 2019. [DOI: 10.22391/fppc.491220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Azevedo H, Amato Khaled N, Santos P, Bernardi Bertonha F, Moreira-Filho CA. Temporal analysis of hippocampal CA3 gene coexpression networks in a rat model of febrile seizures. Dis Model Mech 2018; 11:dmm.029074. [PMID: 29196444 PMCID: PMC5818071 DOI: 10.1242/dmm.029074] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2016] [Accepted: 11/16/2017] [Indexed: 12/11/2022] Open
Abstract
Complex febrile seizures during infancy constitute an important risk factor for development of epilepsy. However, little is known about the alterations induced by febrile seizures that make the brain susceptible to epileptic activity. In this context, the use of animal models of hyperthermic seizures (HS) could allow the temporal analysis of brain molecular changes that arise after febrile seizures. Here, we investigated temporal changes in hippocampal gene coexpression networks during the development of rats submitted to HS. Total RNA samples were obtained from the ventral hippocampal CA3 region at four time points after HS at postnatal day (P) 11 and later used for gene expression profiling. Temporal endpoints were selected for investigating the acute (P12), latent (P30 and P60) and chronic (P120) stages of the HS model. A weighted gene coexpression network analysis was used to characterize modules of coexpressed genes, as these modules might contain genes with similar functions. The transcriptome analysis pipeline consisted of building gene coexpression networks, identifying network modules and hubs, performing gene-trait correlations and examining changes in module connectivity. Modules were functionally enriched to identify functions associated with HS. Our data showed that HS induce changes in developmental, cell adhesion and immune pathways, such as Wnt, Hippo, Notch, Jak-Stat and Mapk. Interestingly, modules involved in cell adhesion, neuronal differentiation and synaptic transmission were activated as early as 1 day after HS. These results suggest that HS trigger transcriptional alterations that could lead to persistent neurogenesis, tissue remodeling and inflammation in the CA3 hippocampus, making the brain prone to epileptic activity. Summary: We carried out a temporal analysis of hippocampal gene coexpression networks to identify relevant genes in a rat model of hyperthermic seizures. These genes were mostly related to immune response, cell adhesion and neurogenesis.
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Affiliation(s)
- Hatylas Azevedo
- Department of Pediatrics, Faculdade de Medicina, University of São Paulo (FMUSP), São Paulo, 05403-000, Brazil
| | - Nathália Amato Khaled
- Department of Pediatrics, Faculdade de Medicina, University of São Paulo (FMUSP), São Paulo, 05403-000, Brazil
| | - Paula Santos
- Department of Pediatrics, Faculdade de Medicina, University of São Paulo (FMUSP), São Paulo, 05403-000, Brazil
| | - Fernanda Bernardi Bertonha
- Department of Pediatrics, Faculdade de Medicina, University of São Paulo (FMUSP), São Paulo, 05403-000, Brazil
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Binini N, Sancini G, Villa C, Dal Magro R, Sansoni V, Rusconi R, Mantegazza M, Grioni D, Talpo F, Toselli M, Combi R. Identification of two mutations in cis in the SCN1A gene in a family showing genetic epilepsy with febrile seizures plus (GEFS+) and idiopathic generalized epilepsy (IGE). Brain Res 2017; 1677:26-32. [DOI: 10.1016/j.brainres.2017.09.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 09/18/2017] [Accepted: 09/20/2017] [Indexed: 11/29/2022]
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10
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Kasahara Y, Ikegaya Y, Koyama R. [Mouse model of febrile seizures]. Nihon Yakurigaku Zasshi 2017; 150:240-245. [PMID: 29118287 DOI: 10.1254/fpj.150.240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kwak BO, Kim K, Kim SN, Lee R. Relationship between iron deficiency anemia and febrile seizures in children: A systematic review and meta-analysis. Seizure 2017; 52:27-34. [PMID: 28957722 DOI: 10.1016/j.seizure.2017.09.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 07/24/2017] [Accepted: 09/14/2017] [Indexed: 11/17/2022] Open
Abstract
PURPOSE The association between iron deficiency anemia (IDA) and febrile seizures (FS) during childhood is inconclusive due to inconsistent results reported in different studies. We performed a systematic review and meta-analysis to determine an association between IDA and FS in children. METHODS We searched PubMed, EMBASE, and Cochrane Library databases for studies published up to August 2015 using the following key words: ["iron deficiency" OR "iron status"] AND ["febrile seizure" OR "febrile convulsion"] AND ["pediatric" OR "infant" OR "child"]. Pooled odds ratios (OR) and 95% confidence intervals (CI) were calculated using standard meta-analysis techniques. Subgroup analysis also was performed. RESULTS A total of 17 studies enrolling 2416 children with FS and 2387 controls were included in the meta-analysis. The results indicated that IDA was significantly associated with FS (OR, 1.98; 95% CI, 1.26-3.13; P=0.003). Subgroup analyses evaluated the diagnostic indices for IDA including serum iron, plasma ferritin, and mean corpuscular volume (MCV). The results indicated that IDA diagnosed on the basis of plasma ferritin (OR, 3.78; 95% CI, 1.80-7.94; P<0.001) or MCV (OR, 2.08; 95% CI, 1.36-3.17; P=0.001) was modestly associated with FS, whereas IDA diagnosed on the basis of two serum iron studies was not associated with FS (OR, 0.57; 95% CI, 0.24-1.37; P=0.210). CONCLUSION The results of this meta-analysis suggest that IDA is associated with an increased risk of FS in children.
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Affiliation(s)
- Byung Ok Kwak
- Department of Microbiology, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Kyungmin Kim
- Department of Pediatrics, Konkuk University Medical Center, Seoul, Republic of Korea
| | - Soo-Nyung Kim
- Department of Obstetrics and Gyneology, Konkuk University Medical Center, Konkuk University School of Medicine, Seoul, Republic of Korea
| | - Ran Lee
- Department of Pediatrics, Konkuk University Medical Center, Konkuk University School of Medicine, 120-1 Neungdong-ro (Hwayang-dong), Gwangjin-gu, Seoul 05030, Republic of Korea.
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Hessel EVS, van Lith HA, Wolterink-Donselaar IG, de Wit M, Groot Koerkamp MJA, Holstege FCP, Kas MJH, Fernandes C, de Graan PNE. Mapping of aFEB3homologous febrile seizure locus on mouse chromosome 2 containing candidate genesScn1aandScn3a. Eur J Neurosci 2016; 44:2950-2957. [DOI: 10.1111/ejn.13420] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 07/10/2016] [Accepted: 08/09/2016] [Indexed: 01/05/2023]
Affiliation(s)
- Ellen V. S. Hessel
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
| | - Hein A. van Lith
- Division of Animal Welfare & Laboratory Animal Science; Department of Animals in Science & Society; Faculty of Veterinary Medicine and Brain Center Rudolf Magnus; Utrecht University; Utrecht The Netherlands
| | - Inge G. Wolterink-Donselaar
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
| | - Marina de Wit
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
| | | | - Frank C. P. Holstege
- Department of Molecular Cancer Research; University Medical Center Utrecht; Utrecht The Netherlands
| | - Martien J. H. Kas
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
- Groningen Institute for Evolutionary Life Sciences; University of Groningen; Groningen The Netherlands
| | - Cathy Fernandes
- Social, Genetic & Developmental Psychiatry Centre; Institute of Psychiatry; Psychology and Neuroscience; King's College London; London UK
| | - Pierre N. E. de Graan
- Brain Center Rudolf Magnus; Department of Translational Neuroscience; University Medical Center Utrecht; Universiteitsweg 100 3584 CG Utrecht The Netherlands
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Wang Z, Zhang Y, Fang J, Yu F, Heng D, Fan Y, Xu J, Peng B, Liu W, Han S, He X. Decreased Methylation Level of H3K27me3 Increases Seizure Susceptibility. Mol Neurobiol 2016; 54:7343-7352. [PMID: 27815838 DOI: 10.1007/s12035-016-0197-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 10/11/2016] [Indexed: 01/01/2023]
Abstract
Epigenetic modifications including histone modifications are associated with seizure development and epileptogenesis; however, its underlying mechanism remains to be elucidated. Dipeptidyl peptidase 4 (DPP4) and IL6 are identified as febrile seizure (FS)-related genes using gene microarray analysis in hyperthermia prone (HP) rats. This purpose of the study focused on exploring whether epigenetic modifications marker histone H3 lysine 27 trimethylation (H3K27me3)-regulated DPP4 and IL6 expression further affected seizures development. Herein, we reported broad between-group differences in the global levels of H3K27me3 with increased seizure severity in vivo. Using chromatin immunoprecipitation (ChIP), we identified markedly decreased H3K27me3 enrichment at their promoters of DPP4 and IL6 in vivo. We further showed that hyperthermia significantly decreased protein levels of H3K27me3, increased mRNA levels of DPP4 and IL6 by decreasing H3K27me3 enrichment at their promoters of DPP4 and IL6 in vitro. Importantly, H3K27me3 loss via enhancer of zeste homolog 2 (EZH2) knockdown promoted expression of DPP4 and IL6 via the same mechanism in vitro. EZH2 knockdown also increased neuronal firing frequency in vitro and FS susceptibility in vivo companied with upregulation expression of DPP4 and IL6. Taken together, our study provided the first evidence that hyperthermia-induced decreased of H3K27me3 promoted seizure susceptibility via regulating the expression pattern of DPP4 and IL6. These findings suggested that the methylation level of H3K27me3 might be a key regulator of seizure susceptibility.
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Affiliation(s)
- Zhongcheng Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Yusong Zhang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Jian Fang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Fang Yu
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Duanhe Heng
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China
| | - Yuanteng Fan
- Department of Neurology, Zhongnan Hospital, Wuhan University, Wuhan, China
| | - Jian Xu
- Weifang Maternity and Child Hospital, Weifang, China
| | - Biwen Peng
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Wanhong Liu
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Song Han
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China.
| | - Xiaohua He
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Donghu Road No. 185, Wuchang, Wuhan, 430071, China.
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Feng B, Chen Z. Generation of Febrile Seizures and Subsequent Epileptogenesis. Neurosci Bull 2016; 32:481-92. [PMID: 27562688 DOI: 10.1007/s12264-016-0054-5] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 07/13/2016] [Indexed: 11/24/2022] Open
Abstract
Febrile seizures (FSs) occur commonly in children aged from 6 months to 5 years. Complex (repetitive or prolonged) FSs, but not simple FSs, can lead to permanent brain modification. Human infants and immature rodents that have experienced complex FSs have a high risk of subsequent temporal lobe epilepsy. However, the causes of FSs and the mechanisms underlying the subsequent epileptogenesis remain unknown. Here, we mainly focus on two major questions concerning FSs: how fever triggers seizures, and how epileptogenesis occurs after FSs. The risk factors responsible for the occurrence of FSs and the epileptogenesis after prolonged FSs are thoroughly summarized and discussed. An understanding of these factors can provide potential therapeutic targets for the prevention of FSs and also yield biomarkers for identifying patients at risk of epileptogenesis following FSs.
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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, Hangzhou, 310058, China
| | - Zhong Chen
- Department of Pharmacology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, School of Medicine, Zhejiang University, Hangzhou, 310058, China.
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Kumar P, Kumar D, Jha SK, Jha NK, Ambasta RK. Ion Channels in Neurological Disorders. ION CHANNELS AS THERAPEUTIC TARGETS, PART A 2016; 103:97-136. [DOI: 10.1016/bs.apcsb.2015.10.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Effects of L-theanine on posttraumatic stress disorder induced changes in rat brain gene expression. ScientificWorldJournal 2014; 2014:419032. [PMID: 25165739 PMCID: PMC4137547 DOI: 10.1155/2014/419032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 04/11/2014] [Accepted: 05/13/2014] [Indexed: 01/02/2023] Open
Abstract
Posttraumatic stress disorder (PTSD) is characterized by the occurrence of a traumatic event that is beyond the normal range of human experience. The future of PTSD treatment may specifically target the molecular mechanisms of PTSD. In the US, approximately 20% of adults report taking herbal products to treat medical illnesses. L-theanine is the amino acid in green tea primarily responsible for relaxation effects. No studies have evaluated the potential therapeutic properties of herbal medications on gene expression in PTSD. We evaluated gene expression in PTSD-induced changes in the amygdala and hippocampus of Sprague-Dawley rats. The rats were assigned to PTSD-stressed and nonstressed groups that received either saline, midazolam, L-theanine, or L-theanine + midazolam. Amygdala and hippocampus tissue samples were analyzed for changes in gene expression. One-way ANOVA was used to detect significant difference between groups in the amygdala and hippocampus. Of 88 genes examined, 17 had a large effect size greater than 0.138. Of these, 3 genes in the hippocampus and 5 genes in the amygdala were considered significant (P < 0.05) between the groups. RT-PCR analysis revealed significant changes between groups in several genes implicated in a variety of disorders ranging from PTSD, anxiety, mood disorders, and substance dependence.
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Tartof SY, Tseng HF, Liu AL, Qian L, Sy LS, Hechter RC, Michael Marcy S, Jacobsen SJ. Exploring the risk factors for vaccine-associated and non-vaccine associated febrile seizures in a large pediatric cohort. Vaccine 2014; 32:2574-81. [DOI: 10.1016/j.vaccine.2014.03.044] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 03/03/2014] [Accepted: 03/13/2014] [Indexed: 11/26/2022]
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Millichap JG, Millichap JJ. Genetic Factor in Etiology of Febrile Seizures. Pediatr Neurol Briefs 2014. [DOI: 10.15844/pedneurbriefs-28-5-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Wang Z, Fan Y, Xu J, Li L, Heng D, Han S, Yin J, Peng B, Liu W, He X. Transcriptome analysis of the hippocampus in novel rat model of febrile seizures. PLoS One 2014; 9:e95237. [PMID: 24736375 PMCID: PMC3988142 DOI: 10.1371/journal.pone.0095237] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 03/24/2014] [Indexed: 01/12/2023] Open
Abstract
Febrile seizures (FS) are the most common type of convulsive events in infants and young children, but the precise underlying genetic mechanism remains to be explored. To investigate the underlying pathogenic factors in FS and subsequent epilepsy, alterations in gene expression between the two new strains of rats (hyperthermia-prone [HP] vs hyperthermia-resistant [HR]), were investigated by using the Whole Rat Genome Oligo Microarray. This process identified 1,140 differentially expressed genes (DEGs; 602 upregulated and 538 downregulated), which were analyzed to determine significant Gene Ontology (GO) categories, signaling pathways and gene networks. Based on the GO analyses, the modified genes are closely related to various FS pathogenesis factors, including immune and inflammatory responses and ion transport. Certain DEGs identified have not been previously examined in relation to FS pathogenesis. Among these genes is dipeptidyl peptidase 4 (DPP4), a gene closely linked to interleukin 6 (IL-6), which played a key role in the gene network analysis. Furthermore, sitagliptin, a DPP4 inhibitor significantly decreased epileptic discharge in rats, observed via electroencephalogram, suggesting an important role for DPP4 in FS. The effectiveness of sitagliptin in reducing seizure activity may occur through a mechanism that stabilizes cellular Ca2+ homeostasis. In addition, DPP4 expression may be regulated by DNA methylation. The hippocampal gene expression profiles in novel rat models of FS provides a large database of candidate genes and pathways, which will be useful for researchers interested in disorders of neuronal excitability.
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Affiliation(s)
- Zhongcheng Wang
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Yuanteng Fan
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Jian Xu
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Liang Li
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Duanhe Heng
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Song Han
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Jun Yin
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Biwen Peng
- Hubei Provincial Key Laboratory of Developmentally Originated Disease, School of Basic Medical Sciences, Wuhan University, Wuhan, China
| | - Wanhong Liu
- Hubei Province Key Laboratory of Allergy and Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
- * E-mail: (WL); (XH)
| | - Xiaohua He
- Department of Pathophysiology, School of Basic Medical Sciences, Wuhan University, Wuhan, China
- * E-mail: (WL); (XH)
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Ku YC, Muo CH, Ku CS, Chen CH, Lee WY, Shen EY, Chang YJ, Kao CH. Risk of subsequent attention deficit-hyperactivity disorder in children with febrile seizures. Arch Dis Child 2014; 99:322-6. [PMID: 24307684 DOI: 10.1136/archdischild-2013-304647] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVE In this study, we obtained relevant data from a nationwide cohort database to investigate the risk of attention deficit-hyperactivity disorder (ADHD) in children with a history of febrile seizures (FS). METHODS We identified 1081 children with FS as the case cohort, and the date of diagnosis was used as an index date. Four controls were matched randomly with each case based on age, sex, urbanisation level, parents' occupation, and index date. We applied Cox's proportional hazards regression to estimate the HR and CI of FS-associated ADHD. RESULTS After 11 years of follow-up, the incidence of ADHD for the FS and control cohorts is 7.83 and 4.72 per 1000 person-years, respectively. The FS cohort was 1.66 times more at risk of ADHD occurrence (95% CI 1.27 to 2.18) than the control cohort. The risk of developing ADHD increased in conjunction with the frequency of FS-related visits. CONCLUSIONS FS may increase the risk of subsequent ADHD occurrence in children. Children who visited physicians for FS more than twice had a significantly higher cumulative incidence of ADHD.
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Affiliation(s)
- Yi-Chia Ku
- Department of Pediatrics, Taichung Veterans General Hospital, , Taichung, Taiwan
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21
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Hessel EVS, de Wit M, Wolterink-Donselaar IG, Karst H, de Graaff E, van Lith HA, de Bruijn E, de Sonnaville S, Verbeek NE, Lindhout D, de Kovel CGF, Koeleman BPC, van Kempen M, Brilstra E, Cuppen E, Loos M, Spijker SS, Kan AA, Baars SE, van Rijen PC, Gosselaar PH, Groot Koerkamp MJA, Holstege FCP, van Duijn C, Vergeer J, Moll HA, Taubøll E, Heuser K, Ramakers GMJ, Pasterkamp RJ, van Nieuwenhuizen O, Hoogenraad CC, Kas MJH, de Graan PNE. Identification of Srp9 as a febrile seizure susceptibility gene. Ann Clin Transl Neurol 2014; 1:239-50. [PMID: 25590037 PMCID: PMC4292741 DOI: 10.1002/acn3.48] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 02/07/2014] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVE Febrile seizures (FS) are the most common seizure type in young children. Complex FS are a risk factor for mesial temporal lobe epilepsy (mTLE). To identify new FS susceptibility genes we used a forward genetic strategy in mice and subsequently analyzed candidate genes in humans. METHODS We mapped a quantitative trait locus (QTL1) for hyperthermia-induced FS on mouse chromosome 1, containing the signal recognition particle 9 (Srp9) gene. Effects of differential Srp9 expression were assessed in vivo and in vitro. Hippocampal SRP9 expression and genetic association were analyzed in FS and mTLE patients. RESULTS Srp9 was differentially expressed between parental strains C57BL/6J and A/J. Chromosome substitution strain 1 (CSS1) mice exhibited lower FS susceptibility and Srp9 expression than C57BL/6J mice. In vivo knockdown of brain Srp9 reduced FS susceptibility. Mice with reduced Srp9 expression and FS susceptibility, exhibited reduced hippocampal AMPA and NMDA currents. Downregulation of neuronal Srp9 reduced surface expression of AMPA receptor subunit GluA1. mTLE patients with antecedent FS had higher SRP9 expression than patients without. SRP9 promoter SNP rs12403575(G/A) was genetically associated with FS and mTLE. INTERPRETATION Our findings identify SRP9 as a novel FS susceptibility gene and indicate that SRP9 conveys its effects through endoplasmic reticulum (ER)-dependent synthesis and trafficking of membrane proteins, such as glutamate receptors. Discovery of this new FS gene and mechanism may provide new leads for early diagnosis and treatment of children with complex FS at risk for mTLE.
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Affiliation(s)
- Ellen V S Hessel
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Marina de Wit
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Inge G Wolterink-Donselaar
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Henk Karst
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Esther de Graaff
- Cell Biology, Faculty of Science, Utrecht UniversityUtrecht, The Netherlands
| | - Hein A van Lith
- Program Emotion and Cognition, Division of Animal Welfare and Laboratory Animal Science, Department of Animals in Science and Society, Faculty of Veterinary Medicine, Utrecht University and Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Ewart de Bruijn
- Hubrecht Institute-KNAW and University Medical Center UtrechtUtrecht, The Netherlands
| | - Sophietje de Sonnaville
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Nienke E Verbeek
- Department of Medical Genetics, University Medical Center UtrechtUtrecht, The Netherlands
| | - Dick Lindhout
- Department of Medical Genetics, University Medical Center UtrechtUtrecht, The Netherlands
- SEIN Epilepsy Institute in the NetherlandsHeemstede, The Netherlands
| | - Carolien G F de Kovel
- Department of Medical Genetics, University Medical Center UtrechtUtrecht, The Netherlands
| | - Bobby P C Koeleman
- Department of Medical Genetics, University Medical Center UtrechtUtrecht, The Netherlands
| | - Marjan van Kempen
- Department of Medical Genetics, University Medical Center UtrechtUtrecht, The Netherlands
| | - Eva Brilstra
- Department of Medical Genetics, University Medical Center UtrechtUtrecht, The Netherlands
| | - Edwin Cuppen
- Hubrecht Institute-KNAW and University Medical Center UtrechtUtrecht, The Netherlands
- Department of Medical Genetics, University Medical Center UtrechtUtrecht, The Netherlands
| | - Maarten Loos
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU UniversityAmsterdam, The Netherlands
| | - Sabine S Spijker
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Neuroscience Campus Amsterdam, VU UniversityAmsterdam, The Netherlands
| | - Anne A Kan
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Susanne E Baars
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
- Master program Neuroscience and Cognition, Utrecht UniversityUtrecht, The Netherlands
| | - Peter C van Rijen
- Department of Neurosurgery, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Peter H Gosselaar
- Department of Neurosurgery, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | | | - Frank C P Holstege
- Department of Molecular Cancer Research, University Medical Center UtrechtUtrecht, The Netherlands
| | - Cornelia van Duijn
- Department of Epidemiology, Erasmus University Medical CenterRotterdam, The Netherlands
| | - Jeanette Vergeer
- Department of Epidemiology, Erasmus University Medical CenterRotterdam, The Netherlands
| | - Henriette A Moll
- Department of Pediatrics, Erasmus Medical CenterRotterdam, The Netherlands
| | - Erik Taubøll
- Department of Neurology, Oslo University HospitalOslo, Norway
| | - Kjell Heuser
- Department of Neurology, Oslo University HospitalOslo, Norway
| | - Geert M J Ramakers
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Onno van Nieuwenhuizen
- Department of Child Neurology, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Casper C Hoogenraad
- Cell Biology, Faculty of Science, Utrecht UniversityUtrecht, The Netherlands
| | - Martien J H Kas
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
| | - Pierre N E de Graan
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center UtrechtUtrecht, The Netherlands
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Yoong M, Seunarine K, Martinos M, Chin RF, Clark CA, Scott RC. Prolonged febrile seizures cause reversible reductions in white matter integrity. NEUROIMAGE-CLINICAL 2013; 3:515-21. [PMID: 24273734 PMCID: PMC3830064 DOI: 10.1016/j.nicl.2013.10.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2013] [Revised: 10/03/2013] [Accepted: 10/17/2013] [Indexed: 11/24/2022]
Abstract
Prolonged febrile seizures (PFS) are the commonest cause of childhood status epilepticus and are believed to carry a risk of neuronal damage, in particular to the mesial temporal lobe. This study was designed to determine: i) the effect of prolonged febrile seizures on white matter and ii) the temporal evolution of any changes seen. 33 children were recruited 1 month following PFS and underwent diffusion tensor imaging (DTI) with repeat imaging at 6 and 12 months after the original episode of PFS. 18 age-matched healthy control subjects underwent similar investigations at a single time point. Tract-based spatial statistics (TBSS) was used to compare fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity (AD) and radial diffusivity (RD) between patients and controls on a voxel-wise basis within the white matter skeleton. Widespread reductions in FA along multiple white matter tracts were found at 1 and 6 months post-PFS, but these had resolved at 12 months. At one month post-PFS the main changes seen were reductions in AD but at 6 months these had predominantly changed to increases in RD. These widespread white matter changes have not previously been noted following PFS. There are many possible explanations, but one plausible hypothesis is that this represents a temporary halting of normal white matter development caused by the seizure, that then resumes and normalises in the majority of children. Widespread reductions in FA occur in children after prolonged febrile seizures. These reductions persist up to 6 months post-PFS but resolve by 1 year. This may represent a seizure-related disruption of white matter development.
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Affiliation(s)
- M Yoong
- Neurosciences Unit, UCL Institute of Child Health, 4/5 Long Yard, London WC1N 3LU, UK ; Imaging and Biophysics Unit, UCL Institute of Child Health, 30 Guilford Street, London WC1N 2AP, UK ; Young Epilepsy, Lingfield, Surrey, UK ; Edinburgh Neurosciences, The University of Edinburgh, Muir Maxwell Epilepsy Centre, Edinburgh, UK
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Waszkielewicz AM, Gunia A, Szkaradek N, Słoczyńska K, Krupińska S, Marona H. Ion channels as drug targets in central nervous system disorders. Curr Med Chem 2013; 20:1241-85. [PMID: 23409712 PMCID: PMC3706965 DOI: 10.2174/0929867311320100005] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 01/14/2013] [Accepted: 01/18/2013] [Indexed: 12/27/2022]
Abstract
Ion channel targeted drugs have always been related with either the central nervous system (CNS), the peripheral nervous system, or the cardiovascular system. Within the CNS, basic indications of drugs are: sleep disorders, anxiety, epilepsy, pain, etc. However, traditional channel blockers have multiple adverse events, mainly due to low specificity of mechanism of action. Lately, novel ion channel subtypes have been discovered, which gives premises to drug discovery process led towards specific channel subtypes. An example is Na(+) channels, whose subtypes 1.3 and 1.7-1.9 are responsible for pain, and 1.1 and 1.2 - for epilepsy. Moreover, new drug candidates have been recognized. This review is focusing on ion channels subtypes, which play a significant role in current drug discovery and development process. The knowledge on channel subtypes has developed rapidly, giving new nomenclatures of ion channels. For example, Ca(2+)s channels are not any more divided to T, L, N, P/Q, and R, but they are described as Ca(v)1.1-Ca(v)3.3, with even newer nomenclature α1A-α1I and α1S. Moreover, new channels such as P2X1-P2X7, as well as TRPA1-TRPV1 have been discovered, giving premises for new types of analgesic drugs.
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Affiliation(s)
- A M Waszkielewicz
- Department of Bioorganic Chemistry, Chair of Organic Chemistry, Faculty of Pharmacy, Jagiellonian University Medical College, 9 Medyczna Street, 30-688 Krakow, Poland.
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Costa C, Prontera P, Sarchielli P, Tonelli A, Bassi MT, Cupini LM, Caproni S, Siliquini S, Donti E, Calabresi P. A novel ATP1A2 gene mutation in familial hemiplegic migraine and epilepsy. Cephalalgia 2013; 34:68-72. [PMID: 23918834 DOI: 10.1177/0333102413498941] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Familial hemiplegic migraine (FHM) is a rare autosomal dominant migraine subtype, characterized by fully reversible motor weakness as a specific symptom of aura. Mutations in the ion transportation coding genes CACNA1A , ATP1A2 and SCN1A are responsible for the FHM phenotype. Moreover, some mutations in ATP1A2 or SCN1A also may lead to epilepsy. CASE Here we report on a three-generation family with five patients having a novel ATP1A2 mutation on exon 19, causing guanine-to-adenine substitution (c.2620G>A, p.Gly874Ser) that co-segregated in the five living relatives with migraine, four of whom had hemiplegic migraine. Moreover, three patients presented with epilepsy, one of whom had generalized epilepsy with febrile seizures plus (GEFS+). CONCLUSIONS The present study provides further evidence on the involvement of ATP1A2 mutations in both migraine and epilepsy, underlying the relevance of genetic analysis in families with a comorbidity of both disorders.
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Affiliation(s)
- Cinzia Costa
- Clinica Neurologica, Università di Perugia, Ospedale S. Maria della Misericordia, Italy
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25
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Grill MF, Ng YT. "Simple febrile seizures plus (SFS+)": more than one febrile seizure within 24 hours is usually okay. Epilepsy Behav 2013; 27:472-6. [PMID: 23624109 DOI: 10.1016/j.yebeh.2013.03.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Revised: 03/01/2013] [Accepted: 03/11/2013] [Indexed: 11/16/2022]
Abstract
This study aimed to investigate whether children with recurrent febrile seizures within a 24-hour period need to be worked up differently from children with simple febrile seizures. Inclusion criteria included the following: (i) children with first seizure cluster between 4 months and 3 years of age, (ii) children who had more than one febrile seizure within 24 hours, and (iii) children who returned to baseline between and after each event. Thirty-two patients met the inclusion criteria over a 3-year period. All patients underwent brain CT and/or MRI and EEG. All head CTs were normal. Two children had abnormal MRI findings - both benign: one is thought to represent postictal changes, and the other one is an incidental arachnoid cyst. Of the 4 abnormal EEGs, one showed epileptiform discharges, while the others showed generalized ictal or postictal features. We propose the term "simple febrile seizures plus (SFS+)" to describe children who have more than one seizure within 24 hours but who are otherwise not different in presentation from children with SFS.
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Affiliation(s)
- Marie F Grill
- Department of Neurology, University of California San Francisco, San Francisco General Hospital, 1001 Potrero Avenue, 4M62 Box 0870, San Francisco, CA 94110, USA
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Abstract
Seizures with fever that result from encephalitis or meningitis usually occur late in the course of febrile illness, and are focal and prolonged. Febrile seizures are by far the most common affecting 5% of the population, followed by posttraumatic seizures and those observed in the setting of a toxic, infectious, or metabolic encephalopathy. This chapter reviews the clinical presentation of the three most common forms, due to fever, trauma, and intoxication. Febrile seizures carry no cognitive or mortality risk. Recurrence risk is increased by young age, namely before 1 year of age. Febrile seizures that persist after the age of 6 years are usually part of the syndrome of Generalized epilepsy febrile seizures plus. These febrile seizures have a strong link with epilepsy since non-febrile seizures may occur later in the same patient and in other members of the same family with an autosomal dominant transmission. Complex febrile seizures, i.e., with focal or prolonged manifestations or followed by focal defect, are related to later mesial temporal epilepsy with hippocampal sclerosis; risk factors are seizure duration and brain malformation. Prophylactic treatment is usually not required in febrile seizures. Early onset of complex seizures is the main indication for AED prophylaxis. Early posttraumatic seizures, i.e., within the first week, are often focal and indicate brain trauma: contusion, hematoma, 24 hours amnesia, and depressed skull fracture are major factors of posttraumatic epilepsy. Prophylaxis with antiepileptic drugs is not effective. Various psychotropic drugs, including antiepileptics, may cause seizures.
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Affiliation(s)
- T Bast
- Epilepsy Centre Kork, Kehl, Germany.
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Sapio MR, Salzmann A, Vessaz M, Crespel A, Lyons PJ, Malafosse A, Fricker LD. Naturally occurring carboxypeptidase A6 mutations: effect on enzyme function and association with epilepsy. J Biol Chem 2012; 287:42900-9. [PMID: 23105115 DOI: 10.1074/jbc.m112.414094] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Carboxypeptidase A6 (CPA6) is a member of the A/B subfamily of M14 metallocarboxypeptidases that is expressed in brain and many other tissues during development. Recently, two mutations in human CPA6 were associated with febrile seizures and/or temporal lobe epilepsy. In this study we screened for additional CPA6 mutations in patients with febrile seizures and focal epilepsy, which encompasses the temporal lobe epilepsy subtype. Mutations found from this analysis as well as CPA6 mutations reported in databases of single nucleotide polymorphisms were further screened by analysis of the modeled proCPA6 protein structure and the functional role of the mutated amino acid. The point mutations predicted to affect activity and/or protein folding were tested by expression of the mutant in HEK293 cells and analysis of the resulting CPA6 protein. Common polymorphisms in CPA6 were also included in this analysis. Several mutations resulted in reduced enzyme activity or CPA6 protein levels in the extracellular matrix. The mutants with reduced extracellular CPA6 protein levels showed normal levels of 50-kDa proCPA6 in the cell, and this could be converted into 37-kDa CPA6 by trypsin, suggesting that protein folding was not greatly affected by the mutations. Interestingly, three of the mutations that reduced extracellular CPA6 protein levels were found in patients with epilepsy. Taken together, these results provide further evidence for the involvement of CPA6 mutations in human epilepsy and reveal additional rare mutations that inactivate CPA6 and could, therefore, also be associated with epileptic phenotypes.
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Affiliation(s)
- Matthew R Sapio
- Department of Neuroscience, Albert Einstein College of Medicine,Bronx, New York 10461,USA
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Hessel EVS, van Lith HA, Wolterink-Donselaar IG, de Wit M, Hendrickx DAE, Kas MJH, de Graan PNE. Mapping an X-linked locus that influences heat-induced febrile seizures in mice. Epilepsia 2012; 53:1399-410. [PMID: 22780306 DOI: 10.1111/j.1528-1167.2012.03575.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
PURPOSE Febrile seizures (FS) are the most common seizure type in children between the age of 6 months and 5 years. Although FS are largely benign, recurrent FS are a major risk factor for developing temporal lobe epilepsy (TLE) later in life. The mechanisms underlying FS are largely unknown; however, family and twin studies indicate that FS susceptibility is under complex genetic control. We have recently developed a phenotypic screen to study the genetics of FS susceptibility in mice. Using this screen in a phenotype-driven genetic strategy we analyzed the C57BL/6J-Chr #(A)/NaJ chromosome substitution strain (CSS) panel. In each CSS line one chromosome of the A/J strain is substituted in a genetically homogeneous C57BL/6J background. The analysis of the CSS panel revealed that A/J chromosomes 1, 2, 6, 10, 13, and X carry at least one quantitative trait locus (QTL) for heat-induced FS susceptibility. The fact that many X-linked genes are highly expressed in the brain and have been implicated in human developmental disorders often presenting with seizures (like fragile X mental retardation) prompted us to map the chromosome X QTL. METHODS C57BL/6J mice were mated with C57BL/6J-Chr X(A) /NaJ (CSSX) to generate F(2)-generations-CXBL6 and BL6CX-originating from CSSX or C57BL/6J mothers, respectively. Heat-induced FS were elicited on postnatal day 14 by exposure to a controlled warm airstream of 50°C. The latency to heat-induced FS is our phenotype. This phenotype has previously been validated by video-electroencephalography (EEG) monitoring. After phenotyping and genotyping the F(2)-population, QTL analysis was performed using R/QTL software. KEY FINDINGS QTL analysis revealed a significant peak with an LOD-score of 3.25. The 1-LOD confidence interval (149,886,866-158,836,462 bp) comprises 52 protein coding genes, of which 34 are known to be brain expressed. Two of these brain-expressed genes have previously been linked to X-linked epilepsies, namely Cdkl5 and Pdha1. SIGNIFICANCE Our results show that the mouse genetics of X-linked FS susceptibility is complex, and that our heat-induced FS-driven genetic approach is a powerful tool for use in unraveling the complexities of this trait in mice. Fine-mapping and functional studies will be required to further identify the X-linked FS susceptibility genes.
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Affiliation(s)
- Ellen V S Hessel
- Rudolf Magnus Institute of Neuroscience, Department of Neuroscience and Pharmacology, University Medical Center Utrecht, Utrecht, The Netherlands
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Kim JA, Connors BW. High temperatures alter physiological properties of pyramidal cells and inhibitory interneurons in hippocampus. Front Cell Neurosci 2012; 6:27. [PMID: 22783167 PMCID: PMC3390787 DOI: 10.3389/fncel.2012.00027] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2012] [Accepted: 06/13/2012] [Indexed: 01/14/2023] Open
Abstract
Temperature has multiple effects on neurons, yet little is known about the effects of high temperature on the physiology of mammalian central neurons. Hyperthermia can influence behavior and cause febrile seizures. We studied the effects of acute hyperthermia on the immature hippocampus in vitro by recording from pyramidal neurons and inhibitory oriens-lacunosum moleculare (O-LM) interneurons (identified by green fluorescent protein (GFP) expression in the GIN mouse line). Warming to 41°C caused depolarization, spontaneous action potentials, reduced input resistance and membrane time constant, and increased spontaneous synaptic activity of most pyramidal cells and O-LM interneurons. Pyramidal neurons of area CA3 were more strongly excited by hyperthermia than those of area CA1. About 90% of O-LM interneurons in both CA1 and CA3 increased their firing rates at hyperthermic temperatures; interneurons in CA3 fired faster than those in CA1 on average. Blockade of fast synaptic transmission did not abolish the effect of hyperthermia on neuronal excitability. Our results suggest that hyperthermia increases hippocampal excitability, particularly in seizure-prone area CA3, by altering the intrinsic membrane properties of pyramidal cells and interneurons.
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Affiliation(s)
- Jennifer A Kim
- Department of Neuroscience, Brown University, Providence RI, USA
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Kipp KH, Opitz B, Becker M, Hofmann J, Krick C, Gortner L, Mecklinger A. Neural correlates of recognition memory in children with febrile seizures: evidence from functional magnetic resonance imaging. Front Hum Neurosci 2012; 6:17. [PMID: 22347857 PMCID: PMC3278706 DOI: 10.3389/fnhum.2012.00017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Accepted: 01/28/2012] [Indexed: 11/13/2022] Open
Abstract
Febrile seizures (FS) are assumed to not have adverse long-term effects on cognitive development. Nevertheless, FS are often associated with hippocampal sclerosis which can imply episodic memory deficits. This interrelation has hardly been studied so far. In the current study 13 children who had suffered from FS during infancy and 14 control children (7 to 9-years-old) were examined for episodic and semantic memory with standardized neuropsychological tests. Furthermore, using functional magnetic resonance imaging (fMRI) we studied neuronal activation while the children performed a continuous recognition memory task. The analysis of the behavioral data of the neuropsychological tests and the recognition memory experiment did not reveal any between-group differences in memory performance. Consistent with other studies fMRI revealed repetition enhancement effects for both groups in a variety of brain regions (e.g., right middle frontal gyrus, left parahippocampal gyrus) and a repetition suppression effect in the right superior temporal gyrus. Different neural activation patterns between both groups were obtained selectively within the right supramarginal gyrus (BA 40). In the control group correct rejections of new items were associated with stronger activation than correctly identified old items (HITs) whereas in the FS group no difference occurred. On the background that the right supramarginal gyrus is assumed to mediate a top-down process to internally direct attention toward recollected information, the results could indicate that control children used strategic recollection in order to reject new items (recall-to-reject). In contrast, the missing effect in the FS group could reflect a lack of strategy use, possibly due to impaired recollective processing. This study demonstrates that FS, even with mainly benign courses, can be accompanied by selective modifications in the neural structures underlying recognition memory.
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Affiliation(s)
- Kerstin H Kipp
- Experimental Neuropsychology Unit, Department of Psychology, Saarland University Saarbruecken, Germany
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Marini C, Mantegazza M. Na+ channelopathies and epilepsy: recent advances and new perspectives. Expert Rev Clin Pharmacol 2012; 3:371-84. [PMID: 22111617 DOI: 10.1586/ecp.10.20] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Mutations of ion channel genes have a major role in the pathogenesis of several epilepsies, confirming that some epilepsies are disorders due to the impairment of ion channel function (channelopathies). Voltage-gated Na(+) channels (VGSCs) play an essential role in neuronal excitability; it is, therefore, not surprising that most mutations associated with epilepsy have been identified in genes coding for VGSCs subunits. Epilepsies linked to VGSCs mutations range in severity from mild disorders, such as benign neonatal-infantile familial seizures and febrile seizures, to severe and drug-resistant epileptic encephalopathies. SCN1A is the most clinically relevant of all of the known epilepsy genes, several hundred mutations have been identified in this gene. This review will summarize recent advances and new perspectives on Na(+) channels and epilepsy. A better understanding of the genetic basis and of how gene defects cause seizures is mandatory to direct future research for newer selective and more efficacious treatments.
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Affiliation(s)
- Carla Marini
- Child Neurology Unit, Pediatric Hospital A. Meyer, University of Firenze, Viale Pieraccini, Florence, Italy.
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Yuan Y. Methylmercury: a potential environmental risk factor contributing to epileptogenesis. Neurotoxicology 2012; 33:119-26. [PMID: 22206970 PMCID: PMC3285480 DOI: 10.1016/j.neuro.2011.12.014] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 12/12/2011] [Accepted: 12/14/2011] [Indexed: 12/29/2022]
Abstract
Epilepsy or seizure disorder is one of the most common neurological diseases in humans. Although genetic mutations in ion channels and receptors and some other risk factors such as brain injury are linked to epileptogenesis, the underlying cause for the majority of epilepsy cases remains unknown. Gene-environment interactions are thought to play a critical role in the etiology of epilepsy. Exposure to environmental chemicals is an important risk factor. Methylmercury (MeHg) is a prominent environmental neurotoxicant, which targets primarily the central nervous system (CNS). Patients or animals with acute or chronic MeHg poisoning often display epileptic seizures or show increased susceptibility to seizures, suggesting that MeHg exposure may be associated with epileptogenesis. This mini-review highlights the effects of MeHg exposure, especially developmental exposure, on the susceptibility of humans and animals to seizures, and discusses the potential role of low level MeHg exposure in epileptogenesis. This review also proposes that a preferential effect of MeHg on the inhibitory GABAergic system, leading to disinhibition of excitatory glutamatergic function, may be one of the potential mechanisms underlying MeHg-induced changes in seizure susceptibility.
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Affiliation(s)
- Yukun Yuan
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824, USA.
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Morar B, Zhelyazkova S, Azmanov DN, Radionova M, Angelicheva D, Guergueltcheva V, Kaneva R, Scheffer IE, Tournev I, Kalaydjieva L, Sander JW. A novel GEFS+ locus on 12p13.33 in a large Roma family. Epilepsy Res 2011; 97:198-207. [DOI: 10.1016/j.eplepsyres.2011.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 08/11/2011] [Accepted: 08/14/2011] [Indexed: 10/17/2022]
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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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Piro RM, Molineris I, Ala U, Di Cunto F. Evaluation of candidate genes from orphan FEB and GEFS+ loci by analysis of human brain gene expression atlases. PLoS One 2011; 6:e23149. [PMID: 21858011 PMCID: PMC3157479 DOI: 10.1371/journal.pone.0023149] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 07/07/2011] [Indexed: 12/19/2022] Open
Abstract
Febrile seizures, or febrile convulsions (FEB), represent the most common form of childhood seizures and are believed to be influenced by variations in several susceptibility genes. Most of the associated loci, however, remain ‘orphan’, i.e. the susceptibility genes they contain still remain to be identified. Further orphan loci have been mapped for a related disorder, genetic (generalized) epilepsy with febrile seizures plus (GEFS+). We show that both spatially mapped and ‘traditional’ gene expression data from the human brain can be successfully employed to predict the most promising candidate genes for FEB and GEFS+, apply our prediction method to the remaining orphan loci and discuss the validity of the predictions. For several of the orphan FEB/GEFS+ loci we propose excellent, and not always obvious, candidates for mutation screening in order to aid in gaining a better understanding of the genetic origin of the susceptibility to seizures.
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Affiliation(s)
- Rosario M Piro
- Molecular Biotechnology Center and Department of Genetics, Biology and Biochemistry, University of Torino, Torino, Italy.
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Terra VC, Machado HR, Sakamoto AC, Arida RM, Scorza FA. When your child with epilepsy dies suddenly: febrile seizures are part of the process? ARQUIVOS DE NEURO-PSIQUIATRIA 2011; 69:384-386. [PMID: 21625770 DOI: 10.1590/s0004-282x2011000300022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 12/23/2010] [Indexed: 05/30/2023]
Abstract
Febrile seizures (FS) affect almost 2-5% of children and factors related to an increase susceptibility of children to FS may involve an imbalance of inflammatory cytokines and genetic factors. FS had low morbidity, but may be associated with the occurrence of late chronic epilepsy. Here we describe factors related to FS and its possible correlation with SUDEP.
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Affiliation(s)
- Vera C Terra
- Centro de Cirurgia de Epilepsia, Departamento de Neurociências e Ciências do Comportamento, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
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Abstract
Inherited episodic neurological disorders are often due to mutations in ion channels or their interacting proteins, termed channelopathies. There are a wide variety of such disorders, from those causing paralysis, to extreme pain, to ataxia. A common theme in these is alteration of action potential properties or synaptic transmission and a resulting increased propensity of the resulting tissue to enter into or stay in an altered excitability state. Manifestations of these disorders are triggered by an array of precipitants, all of which stress the particular affected tissue in some way and aid in propelling its activity into an aberrant state. Study of these disorders has aided in the understanding of disease risk factors and elucidated the cause of clinically related sporadic disorders. The findings from study of these disorders will aid in the diagnosis and efficient targeted treatment of affected patients.
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Affiliation(s)
- Devon P Ryan
- Neuroscience Graduate Program, University of California-San Francisco, San Francisco, CA 94158, USA
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Ohno Y, Ishihara S, Mashimo T, Sofue N, Shimizu S, Imaoku T, Tsurumi T, Sasa M, Serikawa T. Scn1a missense mutation causes limbic hyperexcitability and vulnerability to experimental febrile seizures. Neurobiol Dis 2010; 41:261-9. [PMID: 20875856 DOI: 10.1016/j.nbd.2010.09.013] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 08/15/2010] [Accepted: 09/19/2010] [Indexed: 11/29/2022] Open
Abstract
Mutations of the voltage-gated sodium (Na(v)) channel subunit SCN1A have been implicated in the pathogenesis of human febrile seizures including generalized epilepsy with febrile seizures plus (GEFS+) and severe myoclonic epilepsy in infancy (SMEI). Hyperthermia-induced seizure-susceptible (Hiss) rats are the novel rat model carrying a missense mutation (N1417H) of Scn1a, which is located in the third pore-forming region of the Na(v)1.1 channel. Here, we conducted behavioral and neurochemical studies to clarify the functional relevance of the Scn1a mutation in vivo and the mechanism underlying the vulnerability to hyperthermic seizures. Hiss rats showed markedly high susceptibility to hyperthermic seizures (mainly generalized clonic seizures) which were synchronously associated with paroxysmal epileptiform discharges. Immunohistochemical analysis of brain Fos expression revealed that hyperthermic seizures induced a widespread elevation of Fos-immunoreactivity in the cerebral cortices including the motor area, piriform, and insular cortex. In the subcortical regions, hyperthermic seizures enhanced Fos expression region--specifically in the limbic and paralimbic regions (e.g., hippocampus, amygdala, and perirhinal-entorhinal cortex) without affecting other brain regions (e.g., basal ganglia, diencephalon, and lower brainstem), suggesting a primary involvement of limbic system in the induction of hyperthermic seizures. In addition, Hiss rats showed a significantly lower threshold than the control animals in inducing epileptiform discharges in response to local stimulation of the hippocampus (hippocampal afterdischarges). Furthermore, hyperthermic seizures in Hiss rats were significantly alleviated by the antiepileptic drugs, diazepam and sodium valproate, while phenytoin or ethosuximide were ineffective. The present findings support the notion that Hiss rats are useful as a novel rat model of febrile seizures and suggest that hyperexcitability of limbic neurons associated with Scn1a missense mutation plays a crucial role in the pathogenesis of febrile seizures.
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Affiliation(s)
- Yukihiro Ohno
- Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences, Osaka 569-1094, Japan.
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Zhang C, Wong V, Ng PW, Lui CHT, Sin NC, Wong KS, Baum L, Kwan P. Failure to detect association between polymorphisms of the sodium channel gene SCN1A and febrile seizures in Chinese patients with epilepsy. Epilepsia 2010; 51:1878-81. [DOI: 10.1111/j.1528-1167.2010.02587.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Mashimo T, Ohmori I, Ouchida M, Ohno Y, Tsurumi T, Miki T, Wakamori M, Ishihara S, Yoshida T, Takizawa A, Kato M, Hirabayashi M, Sasa M, Mori Y, Serikawa T. A missense mutation of the gene encoding voltage-dependent sodium channel (Nav1.1) confers susceptibility to febrile seizures in rats. J Neurosci 2010; 30:5744-53. [PMID: 20410126 PMCID: PMC6632336 DOI: 10.1523/jneurosci.3360-09.2010] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 03/02/2010] [Accepted: 03/10/2010] [Indexed: 11/21/2022] Open
Abstract
Although febrile seizures (FSs) are the most common convulsive syndrome in infants and childhood, the etiology of FSs has remained unclarified. Several missense mutations of the Na(v)1.1 channel (SCN1A), which alter channel properties, have been reported in a familial syndrome of GEFS+ (generalized epilepsy with febrile seizures plus). Here, we generated Scn1a-targeted rats carrying a missense mutation (N1417H) in the third pore region of the sodium channel by gene-driven ENU (N-ethyl-N-nitrosourea) mutagenesis. Despite their normal appearance under ordinary circumstances, Scn1a mutant rats exhibited remarkably high susceptibility to hyperthermia-induced seizures, which involve generalized clonic and/or tonic-clonic convulsions with paroxysmal epileptiform discharges. Whole-cell patch-clamp recordings from HEK cells expressing N1417H mutant channels and from hippocampal GABAergic interneurons of N1417H mutant rats revealed a significant shift of the inactivation curve in the hyperpolarizing direction. In addition, clamp recordings clearly showed the reduction in action potential amplitude in the hippocampal interneurons of these rats. These findings suggest that a missense mutation (N1417H) of the Na(v)1.1 channel confers susceptibility to FS and the impaired biophysical properties of inhibitory GABAergic neurons underlie one of the mechanisms of FS.
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Affiliation(s)
- Tomoji Mashimo
- Institute of Laboratory Animals, Graduate School of Medicine, Kyoto University, Kyoto 606-8501, Japan.
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Takano T, Sakaue Y, Sokoda T, Sawai C, Akabori S, Maruo Y, Taga T, Ohno M, Takeuchi Y. Seizure susceptibility due to antihistamines in febrile seizures. Pediatr Neurol 2010; 42:277-9. [PMID: 20304332 DOI: 10.1016/j.pediatrneurol.2009.11.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2009] [Revised: 09/08/2009] [Accepted: 11/02/2009] [Indexed: 11/15/2022]
Abstract
The aim of this study was to determine whether seizure susceptibility due to antihistamines is provoked in patients with febrile seizures. The study population comprised 14 patients with simple febrile seizures and 35 patients with complex febrile seizures. Detailed clinical manifestations were compared between patients with and without administration of antihistamine. The time from fever detection to the seizure onset was significantly shorter in the antihistamine group than that in the nonantihistamine group, and the duration of seizures was significantly longer in the antihistamine group than that in nonantihistamine group. Interleukin-1beta is thought to be associated with causing febrile seizures via its dual role as a pyrogen and convulsant substance. Moreover, interleukin-1beta may activate the turnover of hypothalamic neural histamine. These considerations, along with the present results, suggest that the depletion of hypothalamic neuronal histamine induced by antihistamines may increase neuronal excitability, thereby increasing seizure susceptibility in patients with febrile seizures.
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Affiliation(s)
- Tomoyuki Takano
- Department of Pediatrics, Shiga University of Medical Science, Seta-Tsukinowa, Otsu 520-2192, Japan.
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Abstract
Genetic factors play an increasingly recognized role in idiopathic epilepsies. Since 1995, positional cloning strategies in multi-generational families with autosomal dominant transmission have revealed 11 genes (KCNQ2, KCNQ3, CHRNA4, CHRNA2, CHRNB2, SCN1B, SCN1A, SCN2A, GABRG2, GABRA1, and LGI1) and numerous loci for febrile seizures and epilepsies. To date, all genes with the exception of LGI1 (leucine-rich glioma inactivated 1), encode neuronal ion channel or neurotransmitter receptor subunits. Molecular approaches have revealed great genetic heterogeneity, with the vast majority of genes remaining to be identified. One of the major challenges is now to understand phenotype-genotype correlations. This review focuses on the current knowledge on the molecular basis of these rare Mendelian autosomal dominant forms of idiopathic epilepsies.
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Affiliation(s)
- Stéphanie Baulac
- UPMC/Inserm, UMR_S975, Cricm, F-75013, Bâtiment Pharmacie, Hôpital de la Pitié-Salpêtrière, 47 boulevard de l'hôpital, 75013 Paris, France.
| | - Michel Baulac
- UPMC/Inserm, UMR_S975, Cricm, F-75013, Bâtiment Pharmacie, Hôpital de la Pitié-Salpêtrière, 47 boulevard de l'hôpital, 75013 Paris, France; Center for Epilepsy, AP-HP, Bâtiment Paul Casteigne Hôpital de la Pitié-Salpêtrière, 47 boulevard de l'hôpital, 75013 Paris, France
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Scantlebury MH, Heida JG. Febrile seizures and temporal lobe epileptogenesis. Epilepsy Res 2009; 89:27-33. [PMID: 20005077 DOI: 10.1016/j.eplepsyres.2009.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 10/26/2009] [Accepted: 11/07/2009] [Indexed: 11/19/2022]
Abstract
Febrile seizures (FS) are a common neurological disorder that affects children. Simple FS are thought to be benign but experimental and clinical evidence support that the risk of developing epilepsy after FS increases if the FS are prolonged and the brain is abnormal. In addition, prolonged FS (PFS) have many deleterious long-term effects characterized mainly in the hippocampus but may involve the whole brain and that prompt abortive treatment of PFS may prevent some of the adverse effects. This review focuses on some of the key factors involved in the generation of FS, factors leading to PFS and potential mechanisms and functional correlates leading to temporal lobe epilepsy (TLE).
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Affiliation(s)
- Morris H Scantlebury
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, USA.
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Millichap JG. Influence of SCN1A Gene Mutation on Age of Onset of Febrile Seizures in GEFS+. Pediatr Neurol Briefs 2009. [DOI: 10.15844/pedneurbriefs-23-5-10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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