1
|
Ng ACH, Chahine M, Scantlebury MH, Appendino JP. Channelopathies in epilepsy: an overview of clinical presentations, pathogenic mechanisms, and therapeutic insights. J Neurol 2024; 271:3063-3094. [PMID: 38607431 DOI: 10.1007/s00415-024-12352-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/13/2024]
Abstract
Pathogenic variants in genes encoding ion channels are causal for various pediatric and adult neurological conditions. In particular, several epilepsy syndromes have been identified to be caused by specific channelopathies. These encompass a spectrum from self-limited epilepsies to developmental and epileptic encephalopathies spanning genetic and acquired causes. Several of these channelopathies have exquisite responses to specific antiseizure medications (ASMs), while others ASMs may prove ineffective or even worsen seizures. Some channelopathies demonstrate phenotypic pleiotropy and can cause other neurological conditions outside of epilepsy. This review aims to provide a comprehensive exploration of the pathophysiology of seizure generation, ion channels implicated in epilepsy, and several genetic epilepsies due to ion channel dysfunction. We outline the clinical presentation, pathogenesis, and the current state of basic science and clinical research for these channelopathies. In addition, we briefly look at potential precision therapy approaches emerging for these disorders.
Collapse
Affiliation(s)
- Andy Cheuk-Him Ng
- Clinical Neuroscience and Pediatric Neurology, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada
- Division of Neurology, Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta and Stollery Children's Hospital, Edmonton, AB, Canada
| | - Mohamed Chahine
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
- CERVO, Brain Research Centre, Quebec City, Canada
| | - Morris H Scantlebury
- Clinical Neuroscience and Pediatric Neurology, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada
- Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Calgary, Canada
| | - Juan P Appendino
- Clinical Neuroscience and Pediatric Neurology, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada.
| |
Collapse
|
2
|
Kolesnikova TO, Demin KA, Costa FV, Zabegalov KN, de Abreu MS, Gerasimova EV, Kalueff AV. Towards Zebrafish Models of CNS Channelopathies. Int J Mol Sci 2022; 23:ijms232213979. [PMID: 36430455 PMCID: PMC9693542 DOI: 10.3390/ijms232213979] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 11/06/2022] [Accepted: 11/10/2022] [Indexed: 11/16/2022] Open
Abstract
Channelopathies are a large group of systemic disorders whose pathogenesis is associated with dysfunctional ion channels. Aberrant transmembrane transport of K+, Na+, Ca2+ and Cl- by these channels in the brain induces central nervous system (CNS) channelopathies, most commonly including epilepsy, but also migraine, as well as various movement and psychiatric disorders. Animal models are a useful tool for studying pathogenesis of a wide range of brain disorders, including channelopathies. Complementing multiple well-established rodent models, the zebrafish (Danio rerio) has become a popular translational model organism for neurobiology, psychopharmacology and toxicology research, and for probing mechanisms underlying CNS pathogenesis. Here, we discuss current prospects and challenges of developing genetic, pharmacological and other experimental models of major CNS channelopathies based on zebrafish.
Collapse
Affiliation(s)
| | - Konstantin A. Demin
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 197341 St. Petersburg, Russia
| | - Fabiano V. Costa
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
| | | | - Murilo S. de Abreu
- Moscow Institute of Physics and Technology, 141701 Moscow, Russia
- Correspondence: (M.S.d.A.); (A.V.K.); Tel.: +55-54-99605-9807 (M.S.d.A.); +1-240-899-9571 (A.V.K.); Fax: +1-240-899-9571 (A.V.K.)
| | - Elena V. Gerasimova
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
| | - Allan V. Kalueff
- Neurobiology Program, Sirius University of Science and Technology, 354349 Sochi, Russia
- Institute of Translational Biomedicine, St. Petersburg State University, 199034 St. Petersburg, Russia
- Institute of Experimental Medicine, Almazov National Medical Research Centre, Ministry of Healthcare of Russian Federation, 197341 St. Petersburg, Russia
- Moscow Institute of Physics and Technology, 141701 Moscow, Russia
- Laboratory of Preclinical Bioscreening, Granov Russian Research Center of Radiology and Surgical Technologies, Ministry of Healthcare of Russian Federation, 197758 St. Petersburg, Russia
- Ural Federal University, 620002 Yekaterinburg, Russia
- Scientific Research Institute of Neurosciences and Medicine, 630117 Novosibirsk, Russia
- Correspondence: (M.S.d.A.); (A.V.K.); Tel.: +55-54-99605-9807 (M.S.d.A.); +1-240-899-9571 (A.V.K.); Fax: +1-240-899-9571 (A.V.K.)
| |
Collapse
|
3
|
Zuberi SM, Wirrell E, Yozawitz E, Wilmshurst JM, Specchio N, Riney K, Pressler R, Auvin S, Samia P, Hirsch E, Galicchio S, Triki C, Snead OC, Wiebe S, Cross JH, Tinuper P, Scheffer IE, Perucca E, Moshé SL, Nabbout R. ILAE classification and definition of epilepsy syndromes with onset in neonates and infants: Position statement by the ILAE Task Force on Nosology and Definitions. Epilepsia 2022; 63:1349-1397. [PMID: 35503712 DOI: 10.1111/epi.17239] [Citation(s) in RCA: 197] [Impact Index Per Article: 98.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 03/20/2022] [Accepted: 03/21/2022] [Indexed: 12/20/2022]
Abstract
The International League Against Epilepsy (ILAE) Task Force on Nosology and Definitions proposes a classification and definition of epilepsy syndromes in the neonate and infant with seizure onset up to 2 years of age. The incidence of epilepsy is high in this age group and epilepsy is frequently associated with significant comorbidities and mortality. The licensing of syndrome specific antiseizure medications following randomized controlled trials and the development of precision, gene-related therapies are two of the drivers defining the electroclinical phenotypes of syndromes with onset in infancy. The principal aim of this proposal, consistent with the 2017 ILAE Classification of the Epilepsies, is to support epilepsy diagnosis and emphasize the importance of classifying epilepsy in an individual both by syndrome and etiology. For each syndrome, we report epidemiology, clinical course, seizure types, electroencephalography (EEG), neuroimaging, genetics, and differential diagnosis. Syndromes are separated into self-limited syndromes, where there is likely to be spontaneous remission and developmental and epileptic encephalopathies, diseases where there is developmental impairment related to both the underlying etiology independent of epileptiform activity and the epileptic encephalopathy. The emerging class of etiology-specific epilepsy syndromes, where there is a specific etiology for the epilepsy that is associated with a clearly defined, relatively uniform, and distinct clinical phenotype in most affected individuals as well as consistent EEG, neuroimaging, and/or genetic correlates, is presented. The number of etiology-defined syndromes will continue to increase, and these newly described syndromes will in time be incorporated into this classification. The tables summarize mandatory features, cautionary alerts, and exclusionary features for the common syndromes. Guidance is given on the criteria for syndrome diagnosis in resource-limited regions where laboratory confirmation, including EEG, MRI, and genetic testing, might not be available.
Collapse
Affiliation(s)
- Sameer M Zuberi
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Institute of Health & Wellbeing, Collaborating Centre of European Reference Network EpiCARE, University of Glasgow, Glasgow, UK
| | - Elaine Wirrell
- Divisions of Child and Adolescent Neurology and Epilepsy, Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Elissa Yozawitz
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, Montefiore Medical Center, Bronx, New York, USA
| | - Jo M Wilmshurst
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Nicola Specchio
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesu' Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
| | - Kate Riney
- Neurosciences Unit, Queensland Children's Hospital, South Brisbane, Queensland, Australia.,Faculty of Medicine, University of Queensland, St Lucia, Queensland, Australia
| | - Ronit Pressler
- Clinical Neuroscience, UCL- Great Ormond Street Institute of Child Health, London, UK.,Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children NHS Foundation Trust, Member of European Reference Network EpiCARE, London, UK
| | - Stephane Auvin
- AP-HP, Hôpital Robert-Debré, INSERM NeuroDiderot, DMU Innov-RDB, Neurologie Pédiatrique, Member of European Reference Network EpiCARE, Université de Paris, Paris, France
| | - Pauline Samia
- Department of Paediatrics and Child Health, Aga Khan University, Nairobi, Kenya
| | - Edouard Hirsch
- Neurology Epilepsy Unit "Francis Rohmer", INSERM 1258, FMTS, Strasbourg University, Strasbourg, France
| | - Santiago Galicchio
- Child Neurology Department, Victor J Vilela Child Hospital of Rosario, Santa Fe, Argentina
| | - Chahnez Triki
- Child Neurology Department, LR19ES15 Neuropédiatrie, Sfax Medical School, University of Sfax, Sfax, Tunisia
| | - O Carter Snead
- Pediatric Neurology, Hospital for Sick Children, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Samuel Wiebe
- Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - J Helen Cross
- Programme of Developmental Neurosciences, UCL NIHR BRC Great Ormond Street Institute of Child Health, Great Ormond Street Hospital for Children, Member of European Reference Network EpiCARE, London, UK.,Young Epilepsy, Lingfield, UK
| | - Paolo Tinuper
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy.,IRCCS Istituto delle Scienze Neurologiche, Bologna, Italy
| | - Ingrid E Scheffer
- Austin Health and Royal Children's Hospital, Florey Institute, Murdoch Children's Research Institute, University of Melbourne, Melbourne, Victoria, Australia
| | - Emilio Perucca
- Department of Neuroscience, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Austin Health, University of Melbourne, Heidelberg, Victoria, Australia
| | - Solomon L Moshé
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, Bronx, New York, USA.,Departments of Neuroscience and Pediatrics, Albert Einstein College of Medicine, Bronx, New York, USA.,Montefiore Medical Center, Bronx, New York, USA
| | - Rima Nabbout
- Reference Centre for Rare Epilepsies, Department of Pediatric Neurology, Necker-Enfants Malades University Hospital, APHP, Member of European Reference Network EpiCARE, Institut Imagine, INSERM, UMR 1163, Université Paris cité, Paris, France
| |
Collapse
|
4
|
Amin S, Monaghan M, Aledo-Serrano A, Bahi-Buisson N, Chin RF, Clarke AJ, Cross JH, Demarest S, Devinsky O, Downs J, Pestana Knight EM, Olson H, Partridge CA, Stuart G, Trivisano M, Zuberi S, Benke TA. International Consensus Recommendations for the Assessment and Management of Individuals With CDKL5 Deficiency Disorder. Front Neurol 2022; 13:874695. [PMID: 35795799 PMCID: PMC9251467 DOI: 10.3389/fneur.2022.874695] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 04/05/2022] [Indexed: 11/13/2022] Open
Abstract
CDKL5 Deficiency Disorder (CDD) is a rare, X-linked dominant condition that causes a developmental and epileptic encephalopathy (DEE). The incidence is between ~ 1:40,000 and 1:60,000 live births. Pathogenic variants in CDKL5 lead to seizures from infancy and severe neurodevelopmental delay. During infancy and childhood, individuals with CDD suffer impairments affecting cognitive, motor, visual, sleep, gastrointestinal and other functions. Here we present the recommendations of international healthcare professionals, experienced in CDD management, to address the multisystem and holistic needs of these individuals. Using a Delphi method, an anonymous survey was administered electronically to an international and multidisciplinary panel of expert clinicians and researchers. To provide summary recommendations, consensus was set, a priori, as >70% agreement for responses. In the absence of large, population-based studies to provide definitive evidence for treatment, we propose recommendations for clinical management, influenced by this proposed threshold for consensus. We believe these recommendations will help standardize, guide and improve the medical care received by individuals with CDD.
Collapse
Affiliation(s)
- Sam Amin
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, United Kingdom
| | - Marie Monaghan
- Department of Paediatric Neurology, Bristol Royal Hospital for Children, Bristol, United Kingdom
| | - Angel Aledo-Serrano
- Epilepsy Program, Department of Neurology, Ruber Internacional Hospital, Madrid, Spain
| | - Nadia Bahi-Buisson
- Pediatric Neurology, Necker Enfants Malades, Université de Paris, Paris, France
| | - Richard F Chin
- Royal Hospital for Sick Children, University of Edinburgh, Edinburgh, United Kingdom
| | - Angus J Clarke
- University Hospital of Wales, Cardiff University, Cardiff, United Kingdom
| | - J Helen Cross
- Developmental Neurosciences, UCL NIHR BRC Great Ormond Street Institute of Child Health, London, United Kingdom
| | - Scott Demarest
- Departments of Pediatrics and Neurology, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, United States
| | - Orrin Devinsky
- Department of Neurology, New York University, New York, NY, United States
| | - Jenny Downs
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia.,School of Physiotherapy and Exercise Science, Curtin University, Perth, WA, Australia
| | - Elia M Pestana Knight
- Cleveland Clinic Epilepsy Center, Cleveland Clinic Learner College of Medicine, Cleveland, OH, United States
| | - Heather Olson
- Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children's Hospital, Boston, MA, United States
| | | | - Graham Stuart
- Bristol Heart Institute, Bristol Royal Hospital for Children, University of Bristol, Bristol, United Kingdom
| | - Marina Trivisano
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Sameer Zuberi
- Paediatric Neurosciences Research Group, Royal Hospital for Children, Glasgow, United Kingdom.,College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom
| | - Tim A Benke
- Department of Pediatrics, Pharmacology, Neurology, and Otolaryngology, University of Colorado School of Medicine, Children's Hospital Colorado, Aurora, CO, United States
| |
Collapse
|
5
|
Pressler RM, Cilio MR, Mizrahi EM, Moshé SL, Nunes ML, Plouin P, Vanhatalo S, Yozawitz E, de Vries LS, Puthenveettil Vinayan K, Triki CC, Wilmshurst JM, Yamamoto H, Zuberi SM. The ILAE classification of seizures and the epilepsies: Modification for seizures in the neonate. Position paper by the ILAE Task Force on Neonatal Seizures. Epilepsia 2021; 62:615-628. [PMID: 33522601 DOI: 10.1111/epi.16815] [Citation(s) in RCA: 131] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 12/23/2020] [Accepted: 12/23/2020] [Indexed: 12/23/2022]
Abstract
Seizures are the most common neurological emergency in the neonatal period and in contrast to those in infancy and childhood, are often provoked seizures with an acute cause and may be electrographic-only. Hence, neonatal seizures may not fit easily into classification schemes for seizures and epilepsies primarily developed for older children and adults. A Neonatal Seizures Task Force was established by the International League Against Epilepsy (ILAE) to develop a modification of the 2017 ILAE Classification of Seizures and Epilepsies, relevant to neonates. The neonatal classification framework emphasizes the role of electroencephalography (EEG) in the diagnosis of seizures in the neonate and includes a classification of seizure types relevant to this age group. The seizure type is determined by the predominant clinical feature. Many neonatal seizures are electrographic-only with no evident clinical features; therefore, these are included in the proposed classification. Clinical events without an EEG correlate are not included. Because seizures in the neonatal period have been shown to have a focal onset, a division into focal and generalized is unnecessary. Seizures can have a motor (automatisms, clonic, epileptic spasms, myoclonic, tonic), non-motor (autonomic, behavior arrest), or sequential presentation. The classification allows the user to choose the level of detail when classifying seizures in this age group.
Collapse
Affiliation(s)
- Ronit M Pressler
- Clinical Neuroscience, UCL- Great Ormond Street Institute of Child Health, London, UK.,Department of Clinical Neurophysiology, Great Ormond Street Hospital for Children, NHS Foundation Trust, London, UK
| | - Maria Roberta Cilio
- Division of Pediatric Neurology, Institute for Experimental and Clinical Research, Saint-Luc University Hospital, Université Catholique de Louvain, Brussels, Belgium
| | - Eli M Mizrahi
- Departments of Neurology and Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Solomon L Moshé
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA.,Department of Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
| | - Magda L Nunes
- Pontificia Universidade Catolica do Rio Grande do Sul - PUCRS School of Medicine and the Brain Institute, Porto Alegre, RS, Brazil
| | - Perrine Plouin
- Department of Clinical Neurophysiology, Hospital Necker Enfant Malades, Paris, France
| | - Sampsa Vanhatalo
- Department of Clinical Neurophysiology and BABA center Children's Hospital, HUS Imaging, Neuroscience Center, Helsinki Institute of Life Science, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland
| | - Elissa Yozawitz
- Isabelle Rapin Division of Child Neurology, Saul R. Korey Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA.,Department of Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, USA
| | - Linda S de Vries
- Department of Neonatology, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | - Chahnez C Triki
- Department of Child Neurology, Hedi Chaker Hospital, LR19ES15 Sfax University, Sfax, Tunisia
| | - Jo M Wilmshurst
- Department of Paediatric Neurology, Red Cross War Memorial Children's Hospital, Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Hitoshi Yamamoto
- Department of Pediatrics, St. Marianna University School of Medicine, Kawasaki, Japan
| | - Sameer M Zuberi
- Paediatric Neurosciences Research Group, Royal Hospital for Children & Institute of Health & Wellbeing, University of Glasgow, Glasgow, UK
| |
Collapse
|
6
|
Boylan GB, Kharoshankaya L, Mathieson SR. Diagnosis of seizures and encephalopathy using conventional EEG and amplitude integrated EEG. HANDBOOK OF CLINICAL NEUROLOGY 2019; 162:363-400. [PMID: 31324321 DOI: 10.1016/b978-0-444-64029-1.00018-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Seizures are more common in the neonatal period than at any other time of life, partly due to the relative hyperexcitability of the neonatal brain. Brain monitoring of sick neonates in the NICU using either conventional electroencephalography or amplitude integrated EEG is essential to accurately detect seizures. Treatment of seizures is important, as evidence increasingly indicates that seizures damage the brain in addition to that caused by the underlying etiology. Prompt treatment has been shown to reduce seizure burden with the potential to ameliorate seizure-mediated damage. Neonatal encephalopathy most commonly caused by a hypoxia-ischemia results in an alteration of mental status and problems such as seizures, hypotonia, apnea, and feeding difficulties. Confirmation of encephalopathy with EEG monitoring can act as an important adjunct to other investigations and the clinical examination, particularly when considering treatment strategies such as therapeutic hypothermia. Brain monitoring also provides useful early prognostic indicators to clinicians. Recent use of machine learning in algorithms to continuously monitor the neonatal EEG, detect seizures, and grade encephalopathy offers the exciting prospect of real-time decision support in the NICU in the very near future.
Collapse
Affiliation(s)
- Geraldine B Boylan
- Department of Paediatrics and Child Health, Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland.
| | - Liudmila Kharoshankaya
- Department of Paediatrics and Child Health, Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland
| | - Sean R Mathieson
- Department of Paediatrics and Child Health, Irish Centre for Fetal and Neonatal Translational Research (INFANT), University College Cork, Cork, Ireland
| |
Collapse
|
7
|
Hart AR, Pilling EL, Alix JJP. Neonatal seizures-part 2: Aetiology of acute symptomatic seizures, treatments and the neonatal epilepsy syndromes. Arch Dis Child Educ Pract Ed 2015; 100:226-32. [PMID: 25824891 DOI: 10.1136/archdischild-2014-306388] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2014] [Accepted: 02/25/2015] [Indexed: 01/02/2023]
Abstract
Most neonatal epileptic seizures are provoked by an underlying condition or problem-'acute symptomatic seizures'. However, a few neonatal epilepsy syndromes exist, and these are defined by the constellation of seizure types, EEG findings and family history seen. Making an accurate diagnosis of an epilepsy syndrome can help direct investigations, treatment options and provide prognostic information. This article discusses the investigative approach and treatments for neonatal epileptic seizures, including the neonatal epilepsy syndromes.
Collapse
Affiliation(s)
- Anthony R Hart
- Department of Paediatric and Neonatal Neurology, Sheffield Children's Hospital NHS Foundation Trust, Ryegate Children's Centre, Sheffield, South Yorkshire, UK Department of Neonatology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - Elizabeth L Pilling
- Department of Neonatology, Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK
| | - James J P Alix
- Department of Clinical Neurophysiology, Sheffield Teaching Hospitals NHS Foundation Trust, Royal Hallamshire Hospital, Sheffield, UK
| |
Collapse
|
8
|
Guerrini R, Parrini E. Epilepsy in Rett syndrome, and CDKL5- and FOXG1-gene-related encephalopathies. Epilepsia 2012; 53:2067-78. [PMID: 22998673 DOI: 10.1111/j.1528-1167.2012.03656.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Rett syndrome is an X-linked neurodevelopmental disorder that manifests in early childhood with developmental stagnation, and loss of spoken language and hand use, with the development of distinctive hand stereotypies, severe cognitive impairment, and autistic features. About 60% of patients have epilepsy. Seizure onset before the age of 3 years is unlikely, and onset after age 20 is rare. Diagnosis of Rett syndrome is based on key clinical elements that identify "typical" Rett syndrome but also "variant" or "atypical" forms. Diagnostic criteria have been modified only slightly over time, even after discovering that MECP2 gene alterations are present in >90% of patients with typical Rett syndrome but only in 50-70% of atypical cases. Over the last several years, intragenic or genomic alterations of the CDKL5 and FOXG1 genes have been associated with severe cognitive impairment, early onset epilepsy and, often, dyskinetic movement disorders, which have variably been defined as Rett variants. It is now clearly emerging that epilepsy has distinctive characteristics in typical Rett syndrome and in the different syndromes caused by CDKL5 and FOXG1 gene alterations. The progressive parting of CDKL5- and FOXG1-gene-related encephalopathies from the core Rett syndrome is reflected by the effort to produce clearer diagnostic criteria for typical and atypical Rett syndrome. Efforts to characterize the molecular pathology underlying these developmental encephalopathies are pointing to abnormalities of telencephalic development, neuronal morphogenesis, maturation and maintenance, and dendritic arborization.
Collapse
Affiliation(s)
- Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy.
| | | |
Collapse
|
9
|
Weckhuysen S, Mandelstam S, Suls A, Audenaert D, Deconinck T, Claes LRF, Deprez L, Smets K, Hristova D, Yordanova I, Jordanova A, Ceulemans B, Jansen A, Hasaerts D, Roelens F, Lagae L, Yendle S, Stanley T, Heron SE, Mulley JC, Berkovic SF, Scheffer IE, de Jonghe P. KCNQ2 encephalopathy: emerging phenotype of a neonatal epileptic encephalopathy. Ann Neurol 2012; 71:15-25. [PMID: 22275249 DOI: 10.1002/ana.22644] [Citation(s) in RCA: 350] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE KCNQ2 and KCNQ3 mutations are known to be responsible for benign familial neonatal seizures (BFNS). A few reports on patients with a KCNQ2 mutation with a more severe outcome exist, but a definite relationship has not been established. In this study we investigated whether KCNQ2/3 mutations are a frequent cause of epileptic encephalopathies with an early onset and whether a recognizable phenotype exists. METHODS We analyzed 80 patients with unexplained neonatal or early-infantile seizures and associated psychomotor retardation for KCNQ2 and KCNQ3 mutations. Clinical and imaging data were reviewed in detail. RESULTS We found 7 different heterozygous KCNQ2 mutations in 8 patients (8/80; 10%); 6 mutations arose de novo. One parent with a milder phenotype was mosaic for the mutation. No KCNQ3 mutations were found. The 8 patients had onset of intractable seizures in the first week of life with a prominent tonic component. Seizures generally resolved by age 3 years but the children had profound, or less frequently severe, intellectual disability with motor impairment. Electroencephalography (EEG) at onset showed a burst-suppression pattern or multifocal epileptiform activity. Early magnetic resonance imaging (MRI) of the brain showed characteristic hyperintensities in the basal ganglia and thalamus that later resolved. INTERPRETATION KCNQ2 mutations are found in a substantial proportion of patients with a neonatal epileptic encephalopathy with a potentially recognizable electroclinical and radiological phenotype. This suggests that KCNQ2 screening should be included in the diagnostic workup of refractory neonatal seizures of unknown origin.
Collapse
Affiliation(s)
- Sarah Weckhuysen
- Neurogenetics Group, VIB-Department of Molecular Genetics, University of Antwerp, Antwerp, Belgium
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Melani F, Mei D, Pisano T, Savasta S, Franzoni E, Ferrari AR, Marini C, Guerrini R. CDKL5 gene-related epileptic encephalopathy: electroclinical findings in the first year of life. Dev Med Child Neurol 2011; 53:354-60. [PMID: 21309761 DOI: 10.1111/j.1469-8749.2010.03889.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM Cyclin-dependent kinase-like 5 (CDKL5) gene abnormalities cause an early-onset epileptic encephalopathy. We performed video-electroencephalography (video-EEG) monitoring early in the course of CDKL5-related epileptic encephalopathy in order to examine the early electroclinical characteristics of the condition. METHOD We used video-EEG to monitor six infants (five females, one male) with CDKL5-related epileptic encephalopathy (five mutations; one deletion), at ages 45 days to 12 months and followed them up to the ages of 14 months to 5 years (mean age 23 mo). We focused our analysis on the first year of life. The results were evaluated against those of a comparison group of nine infants (aged below 1y) with epileptic encephalography who had tested negative for CDKL5 mutations and deletions. RESULTS One infant exhibited normal background activity, three exhibited moderate slowing, and two exhibited a suppression burst pattern. Two participants had epileptic spasms and four had a stereotyped complex seizure pattern, which we defined as a 'prolonged' generalized tonic-clonic event consisting of a tonic-tonic/vibratory contraction, followed by a clonic phase with series of spasms, gradually translating into repetitive distal myoclonic jerks. Seizure duration ranged from 2 to 4 minutes. The EEG correlate of each clinical phase included an initial electrodecremental event (tonic vibratory phase), irregular series of sharp waves and spike slow waves (clonic phase with series of spasms), and bilateral rhythmic sharp waves (time locked with myoclonus). INTERPRETATION Infants with CDKL5-related early epileptic encephalopathy can present in the first year of life with an unusual electroclinical pattern of 'prolonged' generalized tonic-clonic seizures.
Collapse
Affiliation(s)
- Federico Melani
- Paediatric Neurology Unit and Laboratories, A. Meyer Children's Hospital, University of Florence, Florence, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Nunes ML, Costa JCD. Sleep and epilepsy in neonates. Sleep Med 2010; 11:665-73. [DOI: 10.1016/j.sleep.2009.10.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Revised: 10/22/2009] [Accepted: 10/28/2009] [Indexed: 11/29/2022]
|
12
|
|
13
|
Singh H, Raj R. Benign familial neonatal convulsions: A family with a rare disorder. Ann Indian Acad Neurol 2008; 11:49-51. [PMID: 19966980 PMCID: PMC2781147 DOI: 10.4103/0972-2327.40227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2007] [Revised: 08/17/2007] [Accepted: 08/21/2007] [Indexed: 11/07/2022] Open
Abstract
The authors report a family from Punjab (India) with 10 members having benign familial neonatal convulsions (also known as benign familial neonatal seizures) in two generations. This disorder is quite rare. The clinical presentation of index case along with the findings of computed tomography of the brain and electroencephalograph is described. Important features of all the family members along with a brief review of the literature are also given.
Collapse
Affiliation(s)
- Harbag Singh
- Department of Neurology, Government Medical College, Rajindera Hospital, Patiala - 147 001, Punjab State, India
| | | |
Collapse
|
14
|
Abstract
Epilepsy is a common neurologic disorder that manifests in diverse ways. There are numerous seizure types and numerous mechanisms by which the brain generates seizures. The two hallmarks of seizure generation are hyperexcitability of neurons and hypersynchrony of neural circuits. A large variety of mechanisms alters the balance between excitation and inhibition to predispose a local or widespread region of the brain to hyperexcitability and hypersynchrony. This review discusses five clinical syndromes that have seizures as a prominent manifestation. These five syndromes differ markedly in their etiologies and clinical features, and were selected for discussion because the seizures are generated at a different 'level' of neural dysfunction in each case: (1) mutation of a specific family of ion (potassium) channels in benign familial neonatal convulsions; (2) deficiency of the protein that transports glucose into the CNS in Glut-1 deficiency; (3) aberrantly formed local neural circuits in focal cortical dysplasia; (4) synaptic reorganization of limbic circuitry in temporal lobe epilepsy; and (5) abnormal thalamocortical circuit function in childhood absence epilepsy. Despite this diversity of clinical phenotype and mechanism, these syndromes are informative as to how pathophysiological processes converge to produce brain hyperexcitability and seizures.
Collapse
Affiliation(s)
- Carl E Stafstrom
- Department of Neurology, University of Wisconsin, Madison, Wisconsin 53792, USA.
| |
Collapse
|
15
|
Wladyka CL, Kunze DL. KCNQ/M-currents contribute to the resting membrane potential in rat visceral sensory neurons. J Physiol 2006; 575:175-89. [PMID: 16777937 PMCID: PMC1819429 DOI: 10.1113/jphysiol.2006.113308] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The M-current is a slowly activating, non-inactivating potassium current that has been shown to be present in numerous cell types. In this study, KCNQ2, Q3 and Q5, the molecular correlates of M-current in neurons, were identified in the visceral sensory neurons of the nodose ganglia from rats through immunocytochemical studies. All neurons showed expression of each of the three proteins. In voltage clamp studies, the cognition-enhancing drug linopirdine (1-50 microM) and its analogue, XE991 (10 microM), quickly and irreversibly blocked a small, slowly activating current that had kinetic properties similar to KCNQ/M-currents. This current activated between -60 and -55 mV, had a voltage-dependent activation time constant of 208 +/- 12 ms at -20 mV, a deactivation time constant of 165 +/- 24 ms at -50 mV and V1/2 of -24 +/- 2 mV, values which are consistent with previous reports for endogenous M-currents. In current clamp studies, these drugs also led to a depolarization of the resting membrane potential at values as negative as -60 mV. Flupirtine (10-20 microM), an M-current activator, caused a 3-14 mV leftward shift in the current-voltage relationship and also led to a hyperpolarization of resting membrane potential. These data indicate that the M-current is present in nodose neurons, is activated at resting membrane potential and that it is physiologically important in regulating excitability by maintaining cells at negative voltages.
Collapse
Affiliation(s)
- Cynthia L Wladyka
- Rammelkamp Centre for Research and Education R326 MetroHealth Medical Centre, 2500 MetroHealth Drive, Cleveland, OH 44109-1998, USA
| | | |
Collapse
|
16
|
Abstract
Childhood is a time of considerable importance for the onset of epilepsy syndromes. Selection of an appropriate antiepileptic drug (AED) is central to its successful management. Different AEDs have various effects depending on whether seizures are focal or generalized and this is often used as a rational basis for drug selection. Syndromes, in which features of both focal and generalized seizures are associated in a single patient, present particular problems for pediatric prescribing and epilepsy management since an AED suitable for one seizure type may be ineffective for, or even aggravate, another seizure type. This review discusses the syndromes with different seizures types, focal and generalized, examines the treatment options that may be useful in each case and highlights the potential of some of the newer AEDs in managing these difficult syndromes.
Collapse
Affiliation(s)
- E Hirsch
- Department of Neurology, Epilepsy Unit, Strasbourg, France.
| |
Collapse
|
17
|
Scheffer IE, Harkin LA, Dibbens LM, Mulley JC, Berkovic SF. Neonatal Epilepsy Syndromes and Generalized Epilepsy with Febrile Seizures Plus (GEFS+). Epilepsia 2005; 46 Suppl 10:41-7. [PMID: 16359471 DOI: 10.1111/j.1528-1167.2005.00358.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
MESH Headings
- Child, Preschool
- Epilepsies, Myoclonic/genetics
- Epilepsy, Benign Neonatal/diagnosis
- Epilepsy, Benign Neonatal/genetics
- Epilepsy, Generalized/diagnosis
- Epilepsy, Generalized/genetics
- Female
- Genetic Heterogeneity
- Humans
- Infant
- KCNQ2 Potassium Channel/genetics
- KCNQ3 Potassium Channel/genetics
- Male
- Mutation
- NAV1.1 Voltage-Gated Sodium Channel
- Nerve Tissue Proteins/genetics
- Phenotype
- Receptors, GABA-A/genetics
- Receptors, GABA-B/genetics
- Seizures, Febrile/diagnosis
- Seizures, Febrile/genetics
- Sodium Channels/genetics
- Voltage-Gated Sodium Channel beta-1 Subunit
Collapse
Affiliation(s)
- Ingrid E Scheffer
- Department of Medicine (Neurology), The University of Melbourne, Austin Health, Melbourne, Victoria.
| | | | | | | | | |
Collapse
|
18
|
Schmitt B, Wohlrab G, Sander T, Steinlein OK, Hajnal BL. Neonatal seizures with tonic clonic sequences and poor developmental outcome. Epilepsy Res 2005; 65:161-8. [PMID: 16039833 DOI: 10.1016/j.eplepsyres.2005.05.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2005] [Revised: 04/04/2005] [Accepted: 05/29/2005] [Indexed: 11/16/2022]
Abstract
Seizures consisting of a tonic followed by a clonic phase have rarely been described in neonates and are not included in the current classifications of neonatal seizures. Our video archive of 105 neonates with seizures or suspected seizures revealed six neonates with such tonic clonic or tonic myoclonic sequences. Two of those neonates had pyridoxine dependent seizures. The other four neonates had drug refractory seizures and demonstrated similarities in electro-clinical pattern, clinical course and outcome. Their seizures started with tonic posturing and after 10-20s tonic posturing was superimposed by focal or multifocal cloni or myocloni. Ictal EEG started with voltage attenuation followed by bilateral or alternating focal epileptic discharges. The interictal EEG was abnormal. One child died, while the other three children became seizure free but had severe motor delay and mental retardation. In one of those three children, a de novo missense mutation was detected in the voltage gated potassium channel gene KCNQ2, indicating a genetic relationship between drug refractory neonatal seizures of unknown etiology with tonic clonic or myoclonic sequences and the well-known syndrome of benign familial neonatal convulsions (BFNC).
Collapse
Affiliation(s)
- Bernhard Schmitt
- University Children's Hospital, Steinwiesstrasse 75, CH-8032 Zürich, Switzerland.
| | | | | | | | | |
Collapse
|
19
|
Callenbach PMC, van den Maagdenberg AMJM, Frants RR, Brouwer OF. Clinical and genetic aspects of idiopathic epilepsies in childhood. Eur J Paediatr Neurol 2005; 9:91-103. [PMID: 15843076 DOI: 10.1016/j.ejpn.2004.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2004] [Revised: 12/11/2004] [Accepted: 12/14/2004] [Indexed: 11/27/2022]
Abstract
The identification of the first genes associated with idiopathic epilepsy has been an important breakthrough in the field of epilepsy research. In almost all cases these genes were found to encode components of voltage- or ligand-gated ion channels or functionally related structures. For many other idiopathic syndromes, there is linkage evidence to one or more chromosomes, but the genes have not yet been identified. Identification of the responsible genes and their gene products will further increase the knowledge of the pathogenic mechanisms involved in epilepsy, and will hopefully facilitate the development of drug targets for the effective treatment of epilepsy. This review gives an overview of the clinical characteristics and an update of genetic research of those idiopathic childhood epilepsies for which genes have been identified and the monogenic idiopathic childhood epilepsies for which mapping data are available.
Collapse
Affiliation(s)
- Petra M C Callenbach
- Department of Neurology, University Medical Centre Groningen, Hanzeplein 1/P.O. Box 30001, 9700 RB Groningen, The Netherlands
| | | | | | | |
Collapse
|
20
|
Abstract
Neonatal seizures typically indicate significant underlying disease.They are poorly classified, under-recognized, and often difficult to treat. Recognition of etiology is often helpful in prognosis and treatment; the most common is hypoxic-ischemic encephalopathy. Patients generally have a poor prognosis, with most developing a severe encephalopathy and epilepsy. Studies suggest that neonatal seizures and their etiology have a significant impact on the developing brain; it is critical to recognize seizures early and initiate immediate antiepileptic therapy. Continuous computerized simultaneous video electroencephalograph monitoring is imperative;at-risk infants will frequently have electrographic seizures without clinical manifestations. Although there are antiepileptic therapies for neonatal seizures, they are ineffective in over 35% of cases. The goal of research should be the development of more effective therapies for neonatal seizures, regardless of etiology.
Collapse
Affiliation(s)
- Mary L Zupanc
- Department of Pediatrics, Children's Hospital of Wisconsin, Medical College of Wisconsin, 9000 W. Wisconsin Avenue, Milwaukee 53226, USA.
| |
Collapse
|
21
|
Patrizi S, Holmes GL, Orzalesi M, Allemand F. Neonatal seizures: characteristics of EEG ictal activity in preterm and fullterm infants. Brain Dev 2003; 25:427-37. [PMID: 12907278 DOI: 10.1016/s0387-7604(03)00031-7] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The neonatal EEG remains one of oldest, yet most valuable, diagnostic and prognostic tests in neonates. The goals of this study were to determine the relationships between the morphology, frequency, and distribution of ictal discharges in the neonatal EEG with age, EEG background activity, and etiology. A total of 156 ictal events were evaluated in 11 preterm (PT) and 25 fullterm (FT) infants. Most of the infants had severe abnormalities of background activity although ictal discharges occurred on both normal and abnormal backgrounds. There was a trend for a closer relationship between behavioral changes during the electroencephalographic seizure when the background activity was normal or moderately abnormal than when background activity was severely abnormal. In both PT and FT infants, the most common site of seizure origin was the temporal lobe. FT infants commonly had sharp waves, spikes, sharp and slow waves, and spike and slow waves at the onset of the ictus while rhythmic delta activity was most common in the PT infants. PT infants typically had a regional onset to the ictus whereas FT infants most frequently had a focal onset. Duration of the ictal events was similar in PT and FT infants and a change in morphology or frequency of the discharges was common during propagation of the ictal discharges in both age groups. There was not a clear relationship between onset, morphology, frequency, or propagation patterns and etiology in either the PT or FT infants. Our results demonstrate that while the type of ictal discharge is related to gestational age, there is a rich variety in the onset, morphology, and frequency of the ictal discharges in both PT and FT infants and that neonatal ictal patterns lack a close correlation with underlying pathology.
Collapse
Affiliation(s)
- Silvia Patrizi
- Department of Neurology, Harvard Medical School, Children's Hospital Boston, Boston, MA, USA
| | | | | | | |
Collapse
|
22
|
Abstract
The neonatal period is defined as the first 28 days of life of a term infant; for premature infants the limit of this period is 44 completed weeks of the infant's conceptional age (CA)-defined as the chronological age plus gestational age (GA) at birth. The clinical and electroencephalographic (EEG) manifestations of seizures during this period are determined primarily by the development features of the immature brain at the time of seizure onset, but are also related to the type and diversity of etiologies and risk-factors for seizures neonates may face early in life. Neonatal seizures may be strikingly different from the clinical and electrical seizures of older children and adults. In addition, findings from basic science investigations suggest that immature animals are more likely to experience seizures in response to injury than more mature animals, although the developing brain is less susceptible to seizure-induced injury.
Collapse
Affiliation(s)
- E M Mizrah
- Section of Neurophysiology, Department of Neurology, Baylor College of Medicine, Houston, Texas 77030, USA.
| |
Collapse
|
23
|
Mizrahi EM, Clancy RR. Neonatal seizures: early-onset seizure syndromes and their consequences for development. MENTAL RETARDATION AND DEVELOPMENTAL DISABILITIES RESEARCH REVIEWS 2001; 6:229-41. [PMID: 11107188 DOI: 10.1002/1098-2779(2000)6:4<229::aid-mrdd2>3.0.co;2-y] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The determination of the developmental consequences of seizure syndromes in the neonate is based upon a number of factors which include: understanding of the clinical and electroencephalographic (EEG) features of neonatal seizures; current theories of the mechanisms by which neonatal seizures are generated; a current classification of neonatal seizures; potential etiologic and risk factors for seizures; and therapies. In addition, different seizure types, mechanisms of generation and etiologies of cerebral dysfunction may vary with conceptional age of the infant. There are a few distinct neonatal epileptic syndromes, which are rare, have been well described: benign neonatal convulsions; benign neonatal familial convulsions; early myoclonic encephalopathy and early infantile epileptic encephalopathy. The prognosis for the first two is relatively good while the outcome for the other two with encephalopathy is catastrophic. However, the majority of neonatal seizures occur as acute, reactive events in association with a wide range of etiologic factors. These etiologic factors, as well as those of the more traditionally defined syndromes, are the main determinants of eventual developmental outcome of neonates who experience seizures. Although experimental data suggests that some epileptic seizures eventually may have physiological, histological, metabolic, or behavioral consequences, there is yet direct evidence in humans to suggest that the occurrence of seizures themselves in the neonate is the main determinant of long-term outcome.
Collapse
Affiliation(s)
- E M Mizrahi
- Section of Neurophysiology, Department of Neurology, and Section of Pediatric Neurology, Department of Pediatrics, Baylor College of Medicine, Houston, Texas 77030, USA.
| | | |
Collapse
|
24
|
Stafstrom CE, Tempel BL. Epilepsy genes: the link between molecular dysfunction and pathophysiology. MENTAL RETARDATION AND DEVELOPMENTAL DISABILITIES RESEARCH REVIEWS 2001; 6:281-92. [PMID: 11107193 DOI: 10.1002/1098-2779(2000)6:4<281::aid-mrdd7>3.0.co;2-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Our understanding of the genetic basis of epilepsy is progressing at a rapid pace. Gene mutations causing several of the inherited epilepsies have been mapped, and several more are likely to be added in coming years. In this review, we summarize the available information on the genetic basis of human epilepsies and epilepsy syndromes, emphasizing how genetic defects may correlate with the pathophysiological mechanisms of brain hyperexcitability. Mutations leading to epilepsy have been identified in genes encoding voltage- and ligand-gated ion channels (benign familial neonatal convulsions, autosomal dominant nocturnal frontal lobe epilepsy, generalized epilepsy with febrile seizures "plus"), neurotransmitter receptors (Angelman syndrome), the molecular cascade of cellular energy production (myoclonic epilepsy with ragged red fibers), and proteins without a known role in neuronal excitability (Unverricht-Lundborg disease). Gene defects can lead to epilepsy by altering multiple and diverse aspects of neuronal function.
Collapse
Affiliation(s)
- C E Stafstrom
- Departments of Neurology and Pediatrics, University of Wisconsin, Madison, Wisconsin 53792, USA.
| | | |
Collapse
|
25
|
Affiliation(s)
- G L Holmes
- Department of Neurology, Children's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| |
Collapse
|
26
|
Prasad AN, Prasad C, Stafstrom CE. Recent advances in the genetics of epilepsy: insights from human and animal studies. Epilepsia 1999; 40:1329-52. [PMID: 10528928 DOI: 10.1111/j.1528-1157.1999.tb02004.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Progress in understanding the genetics of epilepsy is proceeding at a dizzying pace. Due in large part to rapid progress in molecular genetics, gene defects underlying many of the inherited epilepsies have been mapped, and several more are likely to be added each year. In this review, we summarize the available information on the genetic basis of human epilepsies and epilepsy syndromes, and correlate these advances with rapidly expanding information about the mechanisms of epilepsy gained from both spontaneous and transgenic animal models. We also provide practical suggestions for clinicians confronted with families in which multiple members are afflicted with epilepsy.
Collapse
Affiliation(s)
- A N Prasad
- Department of Pediatrics, The Charles A. Janeway Child Health Centre, St. John's, Newfoundland, Canada
| | | | | |
Collapse
|
27
|
Abstract
The significant progress made over the past year in understanding the basis for a form of neonatal seizures can be attributed to the successful positional cloning of two new voltage-gated potassium channel genes. Expression studies have increased our understanding of the biology of these channels and their role in epilepsy.
Collapse
Affiliation(s)
- M Leppert
- University of Utah, Department of Human Genetics, Salt Lake City, USA.
| | | |
Collapse
|
28
|
Maihara T, Tsuji M, Higuchi Y, Hattori H. Benign familial neonatal convulsions followed by benign epilepsy with centrotemporal spikes in two siblings. Epilepsia 1999; 40:110-3. [PMID: 9924911 DOI: 10.1111/j.1528-1157.1999.tb01997.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To report on sibling cases with benign familial neonatal convulsions (BFNC) followed by benign epilepsy with centrotemporal spikes (BECT). METHODS Case histories and EEGs were obtained for the two siblings with neonatal and subsequent epileptic seizures in one pedigree with BFNC. RESULTS The family included six affected cases of BFNC in two generations: the proband, the proband's mother and two sisters, and the proband's maternal uncle and his daughter. The proband developed a generalized tonic convulsion 2 days after birth with no apparent cause and normal interictal EEG, and experienced a total of 18 episodes of tonic or clonic seizures or both by age 9 months. In the follow-up course, an EEG recording showed rolandic discharges at 2 years, and a sylvian seizure occurred at 4 years during sleep. On carbamazepine therapy, the last seizure was recorded at 9 years after a total of 11 episodes of sylvian seizures, with normal EEGs after 12 years. The proband's sister experienced nine episodes of brief tonic seizures between 7 and 9 days after birth, and also developed eight episodes of sylvian seizures from 4 to 7 years, with rolandic discharges on EEG until age 9 years. All of the family members had normal psychomotor development, with no neurologic sequelae. CONCLUSIONS This report of BFNC followed by BECT in sibling cases is significant in view of the genetic analysis and the classification of epilepsies and epileptic syndromes.
Collapse
Affiliation(s)
- T Maihara
- Department of Pediatrics, Japanese Red Cross Society Wakayama Medical Center
| | | | | | | |
Collapse
|
29
|
Abstract
Clinical neurophysiologic studies have an important role in the diagnosis and management of the patient with epilepsy. Epilepsy is a clinical diagnosis and the EEG is an important adjunct used to differentiate epileptic seizures from nonepileptic events, refine the diagnosis of epilepsy into specific seizure types and epileptic syndromes, and provide a measure of brain function. The value of the EEG is highly dependent on the clinical context in which it is being applied. In some epilepsies the interictal EEG may be diagnostic whereas in others an ictal recording may be necessary to obtain a specific diagnosis. Both the interictal and ictal EEG characteristics vary with specific seizure types and epilepsies and are described in detail in this review. The usefulness of the EEG in the management of epilepsy and in aiding in the decision to discontinue antiepileptic therapy is also discussed.
Collapse
Affiliation(s)
- E J Novotny
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut 06510, USA
| |
Collapse
|
30
|
Terwindt GM, Ophoff RA, Lindhout D, Haan J, Halley DJ, Sandkuijl LA, Brouwer OF, Frants RR, Ferrari MD. Partial cosegregation of familial hemiplegic migraine and a benign familial infantile epileptic syndrome. Epilepsia 1997; 38:915-21. [PMID: 9579893 DOI: 10.1111/j.1528-1157.1997.tb01257.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE We studied a large Dutch-Canadian family, in which two very rare hereditary paroxysmal neurologic disorders, familial hemiplegic migraine (FHM) and a "benign familial infantile epileptic syndrome" concur and partially cosegregate. FHM is a dominantly inherited subtype of migraine with attacks of hemiparesis, linked to chromosome 19p13 in 50% of the families tested. Recently mutations in a brain-specific P/Q-type Ca2+ channel alpha1 subunit gene (CACNL1A4) were identified in families with chromosome 19-linked FHM. The infantile epileptic syndrome resembles to two other dominantly inherited benign epilepsies occurring in the first year of life, benign familial neonatal convulsions (BFNC), assigned to chromosomes 20q13.2 and 8q, and benign infantile familial convulsions (BIFC), as yet unlinked. METHODS Linkage analysis was performed for the known locations of FHM and BFNC. The question whether the two conditions in this family can be caused by a single gene defect was addressed by additional linkage analysis. RESULTS We excluded linkage of the infantile convulsions to markers on chromosome 20q13.2, 8q, or 19p13. This indicates the existence of a third locus for benign familial convulsions in the first year of life. Linkage of FHM to these markers was not formally excluded but seems very unlikely. Statistical analysis of whether, in this family, both conditions are caused by a single gene defect was inconclusive. CONCLUSIONS We describe a "benign familial infantile epileptic syndrome" with attacks of FHM at a later age. Further genetic studies in this family may help to unravel the genetic basis of epilepsy or migraine or both.
Collapse
Affiliation(s)
- G M Terwindt
- Department of Neurology, Leiden University Medical Center, The Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Alfonso I, Hahn JS, Papazian O, Martinez YL, Reyes MA, Aicardi J. Bilateral tonic-clonic epileptic seizures in non-benign familial neonatal convulsions. Pediatr Neurol 1997; 16:249-51. [PMID: 9165519 DOI: 10.1016/s0887-8994(97)89978-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We report an electroclinical pattern considered characteristic of benign familial neonatal convulsions (BFNC) in two neonates without BFNC. Both neonates were products of uncomplicated pregnancies, labor, and deliveries. The cause of the seizures was not established. There was no family history of seizures or epilepsy. Seizures started on the second and third days after birth. Ten seizures were captured by continuous video-EEG telemetry. The electroclinical events began with generalized tonic posturing coinciding with the appearance of diffuse attenuation of the EEG activity. After several seconds, bilateral clonic movements accompanied by bilateral repetitive sharp waves or spikes occurred in the EEG. One patient had normal development; the other became autistic. We conclude that the electroclinical pattern occurring in BFNC can occur in other types of neonatal seizures.
Collapse
Affiliation(s)
- I Alfonso
- Miami Children's Hospital, Department of Neurology, Florida, USA
| | | | | | | | | | | |
Collapse
|
32
|
Psenka TM, Holden KR. Benign familial neonatal convulsions; psychosocial adjustment to the threat of recurrent seizures. Seizure 1996; 5:243-5. [PMID: 8902929 DOI: 10.1016/s1059-1311(96)80044-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Forty families have experienced benign familial neonatal convulsions (BFNC) since it was first described by Rett and Teubel in 1964. [Rett, A. and Teubel, R. Neugeborenen Krampfe im Rahmen einer epileptisch belasten Familie. Wiener Klinische Wochenschrift 1964; 76: 609-613.] Diagnosis is based on a benign neonatal course, family history, and seizures which usually end spontaneously by six months of age. The absence of subsequent epilepsy makes BFNC a retrospective diagnosis. Consequently there is a considerable length of time during which parents may anxiously follow their child's development. We describe a child with BFNC whose family has experienced five generations of BFNC yet chose to react to the myths and misconceptions of epilepsy and circumvent updated experience supported by the recent medical literature. We have identified three areas in which appropriate physician intervention and patient education may reduce the magnitude of psychosocial disruptions: at the initial seizure, during childrearing and parenting, and in preparation of the patient for future independent decision making. By recognizing the magnitude of social, psychological, and economic disruptions affecting the child and family and by addressing communication issues during the initial diagnosis and follow-up period, we maximize our opportunity to break the cycle of mis-information and anxiety surrounding "benign' seizures.
Collapse
Affiliation(s)
- T M Psenka
- Medical University of South Carolina, Charleston 29425, USA
| | | |
Collapse
|
33
|
|
34
|
Abstract
Recent advances in neuroepidemiologic and molecular biological techniques have facilitated a growing understanding of the role that inherited factors play in epileptogenesis. During the last few years linkage analysis has mapped gene loci associated with the following epilepsy syndromes: benign familial neonatal convulsions, juvenile myoclonic epilepsy, Unverricht-Lundborg/Baltic/Mediterranean progressive myoclonic epilepsies, the juvenile form of ceroid lipofuscinosis, sialidosis I, and the myoclonus epilepsy with ragged red fibers (MERRF) syndrome. In addition, characterization of the inheritance patterns of other syndromes such as childhood epilepsy with occipital paroxysms and febrile convulsions has improved. It is apparent that a significant amount of clinical and genetic heterogeneity exists, which emphasizes the importance of accurate clinical classification. As genetic markers are found for well-defined groups of patients, traditional means of classification (seizure type, pathologic markers, progressive course, etc.) become less meaningful. It is proposed that the components of the phenotype of an epilepsy syndrome (eg, age of onset, seizure type, electroencephalographic pattern) may be controlled by multiple genes.
Collapse
Affiliation(s)
- J R Buchhalter
- Division of Pediatric Neurology, Oregon Health Sciences University, Portland 97201-2984
| |
Collapse
|
35
|
Abstract
The evolution of the diagnosis, etiology, management, and prognosis of neonatal seizures over the past two decades is reviewed. Seizures in the neonate are unique and require special classification. They result from acquired or congenital abnormalities of the central nervous system. Clustering of prognostic parameters, including seizure characteristics, perinatal factors, neurologic signs, cause, and neuroimaging and electroencephalographic abnormalities, allows neonatal seizures to be viewed as clinical syndromes with predictable outcomes.
Collapse
Affiliation(s)
- S M Bernes
- Department of Neurology, Phoenix Children's Hospital, Arizona
| | | |
Collapse
|
36
|
Malafosse A, Beck C, Bellet H, Di Capua M, Dulac O, Echenne B, Fusco L, Lucchini P, Ricci S, Sebastianelli R. Benign infantile familial convulsions are not an allelic form of the benign familial neonatal convulsions gene. Ann Neurol 1994; 35:479-82. [PMID: 8154876 DOI: 10.1002/ana.410350417] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Benign infantile familial convulsions (BIFC) and benign familial neonatal convulsions (BFNC) are two forms of familial convulsions having an age of onset within the first year of life. The gene responsible for BFNC has been mapped to chromosome 20q in the close vicinity of D20S19 and D20S20 markers. We performed linkage analysis between BIFC and D20S19-D20S20 in eight families in order to know whether the BFNC gene is also implicated in BIFC. Several apparent obligate crossovers between affected members were detected. The data here presented demonstrate that the BFNC gene is not responsible for BIFC.
Collapse
Affiliation(s)
- A Malafosse
- Laboratory of Experimental Medicine, CNRS UPR 9008-INSERM U249, Montpellier, France
| | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Millichap JG. Benign Neonatal Familial Convulsions. Pediatr Neurol Briefs 1993. [DOI: 10.15844/pedneurbriefs-7-12-8] [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
|