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Cipriani V, Vestito L, Magavern EF, Jacobsen JO, Arno G, Behr ER, Benson KA, Bertoli M, Bockenhauer D, Bowl MR, Burley K, Chan LF, Chinnery P, Conlon P, Costa M, Davidson AE, Dawson SJ, Elhassan E, Flanagan SE, Futema M, Gale DP, García-Ruiz S, Corcia CG, Griffin HR, Hambleton S, Hicks AR, Houlden H, Houlston RS, Howles SA, Kleta R, Lekkerkerker I, Lin S, Liskova P, Mitchison H, Morsy H, Mumford AD, Newman WG, Neatu R, O'Toole EA, Ong AC, Pagnamenta AT, Rahman S, Rajan N, Robinson PN, Ryten M, Sadeghi-Alavijeh O, Sayer JA, Shovlin CL, Taylor JC, Teltsh O, Tomlinson I, Tucci A, Turnbull C, van Eerde AM, Ware JS, Watts LM, Webster AR, Westbury SK, Zheng SL, Caulfield M, Smedley D. Rare disease gene association discovery from burden analysis of the 100,000 Genomes Project data. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.12.20.23300294. [PMID: 38196618 PMCID: PMC10775325 DOI: 10.1101/2023.12.20.23300294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2024]
Abstract
To discover rare disease-gene associations, we developed a gene burden analytical framework and applied it to rare, protein-coding variants from whole genome sequencing of 35,008 cases with rare diseases and their family members recruited to the 100,000 Genomes Project (100KGP). Following in silico triaging of the results, 88 novel associations were identified including 38 with existing experimental evidence. We have published the confirmation of one of these associations, hereditary ataxia with UCHL1 , and independent confirmatory evidence has recently been published for four more. We highlight a further seven compelling associations: hypertrophic cardiomyopathy with DYSF and SLC4A3 where both genes show high/specific heart expression and existing associations to skeletal dystrophies or short QT syndrome respectively; monogenic diabetes with UNC13A with a known role in the regulation of β cells and a mouse model with impaired glucose tolerance; epilepsy with KCNQ1 where a mouse model shows seizures and the existing long QT syndrome association may be linked; early onset Parkinson's disease with RYR1 with existing links to tremor pathophysiology and a mouse model with neurological phenotypes; anterior segment ocular abnormalities associated with POMK showing expression in corneal cells and with a zebrafish model with developmental ocular abnormalities; and cystic kidney disease with COL4A3 showing high renal expression and prior evidence for a digenic or modifying role in renal disease. Confirmation of all 88 associations would lead to potential diagnoses in 456 molecularly undiagnosed cases within the 100KGP, as well as other rare disease patients worldwide, highlighting the clinical impact of a large-scale statistical approach to rare disease gene discovery.
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Singh V, Ryan JM, Auerbach DS. It is premature for a unified hypothesis of sudden unexpected death in epilepsy: A great amount of research is still needed to understand the multisystem cascade. Epilepsia 2023; 64:2006-2010. [PMID: 37129136 DOI: 10.1111/epi.17636] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/10/2023] [Accepted: 05/01/2023] [Indexed: 05/03/2023]
Affiliation(s)
- Veronica Singh
- Department of Pharmacology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Justin M Ryan
- Department of Pharmacology, SUNY Upstate Medical University, Syracuse, New York, USA
| | - David S Auerbach
- Department of Pharmacology, SUNY Upstate Medical University, Syracuse, New York, USA
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Zhou Y, Hao N, Sander JW, Lin X, Xiong W, Zhou D. KCNH2 variants in a family with epilepsy and long QT syndrome: A case report and literature review. Epileptic Disord 2023; 25:492-499. [PMID: 36946251 DOI: 10.1002/epd2.20046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2022] [Revised: 03/07/2023] [Accepted: 03/12/2023] [Indexed: 03/23/2023]
Abstract
OBJECTIVE Genes associated with Long QT syndromes (LQTS), such as KCNQ1, KCNH2, and SCN5A, are common causes of epilepsy. The Arg 744* variant of KCNH2 has been previously reported in people with epilepsy or LQTS, but none of these patients were reported to simultaneously suffer from epilepsy and LQTS. Herein, we report the case of a family with epilepsy and cardiac disorders. METHOD The proband, a 25-year-old woman, with a family history of epilepsy and LQTS was followed at West China Hospital. The proband experienced her first seizure at the age of seven. Video electroencephalograms (vEEGs) showed epileptic discharges. Her 24-h dynamic electrocardiograms 2 (ECGs) showed QTc prolongation. The proband's mother, who is 50 years old, had her first generalized tonic-clonic seizure (GTCS) at the age of 18 years old. After she gave birth at the age of 25, the frequency of seizures increased, so antiepileptic therapy was initiated. When she was 28 years old, she complained of palpitations and syncope for the first time, and QTc prolongation was detected on her 24-h dynamic ECGs. The proband's grandmother also had complaints of palpitations and syncope at the age of 73. Her 24-h dynamic ECGs indicated supraventricular arrhythmia, with the lowest heart rate being 41 bpm, so she agreed to a pacemaker. Considering the young patient's family history, blood samples of the patient and her parents were collected for genetic analysis. RESULTS A heterozygous variant of KCNH2 [c.2230 (exon9) C>T, p. Arg744Ter, 416, NM_000238, rs189014161] was found in the proband and her mother. According to the guidelines of the American College of Medical Genetics and Genomics and the Association for Molecular Pathology, we classified the KCNH2 variant as pathogenic. SIGNIFICANCE This study expands the clinical phenotype of the Arg 744* KCNH2 pathogenic variant. In the context of channelopathies, because of the genetic susceptibility of the brain and the heart, the risk of comorbidity should be considered. This also indicates the importance of precise antiepileptic drug (AED) management and regular ECG monitoring for patients with channelopathies.
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Affiliation(s)
- Yu Zhou
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, China
- Institute of Brain Science and Brain-inspired technology of West China Hospital, Sichuan University, Chengdu, China
| | - Nanya Hao
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, China
- Institute of Brain Science and Brain-inspired technology of West China Hospital, Sichuan University, Chengdu, China
| | - Josemir W Sander
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, China
- Institute of Brain Science and Brain-inspired technology of West China Hospital, Sichuan University, Chengdu, China
- NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, Queen Square, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter, United Kingdom & Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Xu Lin
- Department of Neurology, The Affiliated Chengdu 363 Hospital of Southwest Medical University, Chengdu, Sichuan, China
| | - Weixi Xiong
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, China
- Institute of Brain Science and Brain-inspired technology of West China Hospital, Sichuan University, Chengdu, China
| | - Dong Zhou
- Department of Neurology, West China Hospital of Sichuan University, Chengdu, China
- Institute of Brain Science and Brain-inspired technology of West China Hospital, Sichuan University, Chengdu, China
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Yu C, Deng XJ, Xu D. Gene mutations in comorbidity of epilepsy and arrhythmia. J Neurol 2023; 270:1229-1248. [PMID: 36376730 DOI: 10.1007/s00415-022-11430-2] [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: 07/31/2022] [Revised: 10/14/2022] [Accepted: 10/15/2022] [Indexed: 11/16/2022]
Abstract
Epilepsy is one of the most common neurological disorders, and sudden unexpected death in epilepsy (SUDEP) is the most severe outcome of refractory epilepsy. Arrhythmia is one of the heterogeneous factors in the pathophysiological mechanism of SUDEP with a high incidence in patients with refractory epilepsy, increasing the risk of premature death. The gene co-expressed in the brain and heart is supposed to be the genetic basis between epilepsy and arrhythmia, among which the gene encoding ion channel contributes to the prevalence of "cardiocerebral channelopathy" theory. Nevertheless, this theory could only explain the molecular mechanism of comorbid arrhythmia in part of patients with epilepsy (PWE). Therefore, we summarized the mutant genes that can induce comorbidity of epilepsy and arrhythmia and the possible corresponding treatments. These variants involved the genes encoding sodium, potassium, calcium and HCN channels, as well as some non-ion channel coding genes such as CHD4, PKP2, FHF1, GNB5, and mitochondrial genes. The relationship between genotype and clinical phenotype was not simple linear. Indeed, genes co-expressed in the brain and heart could independently induce epilepsy and/or arrhythmia. Mutant genes in brain could affect cardiac rhythm through central or peripheral regulation, while in the heart it could also affect cerebral electrical activity by changing the hemodynamics or internal environment. Analysis of mutations in comorbidity of epilepsy and arrhythmia could refine and expand the theory of "cardiocerebral channelopathy" and provide new insights for risk stratification of premature death and corresponding precision therapy in PWE.
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Affiliation(s)
- Cheng Yu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China
| | - Xue-Jun Deng
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China
| | - Da Xu
- Department of Neurology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1277 Jiefang Avenue, Wuhan, 430022, Hubei Province, China.
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KCNH2 encodes a nuclear-targeted polypeptide that mediates hERG1 channel gating and expression. Proc Natl Acad Sci U S A 2023; 120:e2214700120. [PMID: 36626562 PMCID: PMC9934303 DOI: 10.1073/pnas.2214700120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
KCNH2 encodes hERG1, the voltage-gated potassium channel that conducts the rapid delayed rectifier potassium current (IKr) in human cardiac tissue. hERG1 is one of the first channels expressed during early cardiac development, and its dysfunction is associated with intrauterine fetal death, sudden infant death syndrome, cardiac arrhythmia, and sudden cardiac death. Here, we identified a hERG1 polypeptide (hERG1NP) that is targeted to the nuclei of immature cardiac cells, including human stem cell-derived cardiomyocytes (hiPSC-CMs) and neonatal rat cardiomyocytes. The nuclear hERG1NP immunofluorescent signal is diminished in matured hiPSC-CMs and absent from adult rat cardiomyocytes. Antibodies targeting distinct hERG1 channel epitopes demonstrated that the hERG1NP signal maps to the hERG1 distal C-terminal domain. KCNH2 deletion using CRISPR simultaneously abolished IKr and the hERG1NP signal in hiPSC-CMs. We then identified a putative nuclear localization sequence (NLS) within the distal hERG1 C-terminus, 883-RQRKRKLSFR-892. Interestingly, the distal C-terminal domain was targeted almost exclusively to the nuclei when overexpressed HEK293 cells. Conversely, deleting the NLS from the distal peptide abolished nuclear targeting. Similarly, blocking α or β1 karyopherin activity diminished nuclear targeting. Finally, overexpressing the putative hERG1NP peptide in the nuclei of HEK cells significantly reduced hERG1a current density, compared to cells expressing the NLS-deficient hERG1NP or GFP. These data identify a developmentally regulated polypeptide encoded by KCNH2, hERG1NP, whose presence in the nucleus indirectly modulates hERG1 current magnitude and kinetics.
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Cerebral Seizures in an Adolescent with Jervell and Lange-Nielsen Syndrome: It May Not Be Epilepsy. Clin Pract 2022; 12:677-685. [PMID: 36136864 PMCID: PMC9498825 DOI: 10.3390/clinpract12050070] [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: 07/22/2022] [Revised: 08/18/2022] [Accepted: 08/23/2022] [Indexed: 12/02/2022] Open
Abstract
A 13-year-old girl with Jervell and Lange-Nielsen syndrome associated congenital long QT syndrome (LQTS) and central deafness was admitted for generalized seizures. LQTS had been diagnosed after birth and confirmed at genetic testing. β-blocker treatment was immediately started. Despite this, since the age of 12 months, recurrent cerebral seizures occurred leading to the diagnosis of epilepsy. Anti-convulsive therapy was initiated but without success. At the last admission, nadolol dosage seemed infratherapeutic. Considering malignant ventricular arrhythmias as the cause of seizures, the β-blocker dosage was adjusted to weight and levels of magnesium and potassium optimized. Furthermore, the patient received an implantable Medtronic Reveal LINQ Recorder®. Since then, the adolescent has been asymptomatic with no arrhythmia documented. LQTS is due to one or more mutations of genes coding for ion channels. It may induce malignant ventricular arrhythmias and is a major cause of sudden cardiac death in children. Generalized cerebral seizures are extra-cardiac manifestations caused by decreased cerebral perfusion during ventricular arrhythmia. They are commonly misinterpreted as manifestations of epilepsy. For any patient with known or unknown LQTS who presents seizures with resistance to anti-convulsive therapy, a cardiac electrophysiological investigation should be performed promptly to ensure etiological diagnosis and optimize treatment.
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Sanchez-Conde FG, Jimenez-Vazquez EN, Auerbach DS, Jones DK. The ERG1 K+ Channel and Its Role in Neuronal Health and Disease. Front Mol Neurosci 2022; 15:890368. [PMID: 35600076 PMCID: PMC9113952 DOI: 10.3389/fnmol.2022.890368] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Accepted: 04/11/2022] [Indexed: 11/30/2022] Open
Abstract
The ERG1 potassium channel, encoded by KCNH2, has long been associated with cardiac electrical excitability. Yet, a growing body of work suggests that ERG1 mediates physiology throughout the human body, including the brain. ERG1 is a regulator of neuronal excitability, ERG1 variants are associated with neuronal diseases (e.g., epilepsy and schizophrenia), and ERG1 serves as a potential therapeutic target for neuronal pathophysiology. This review summarizes the current state-of-the-field regarding the ERG1 channel structure and function, ERG1’s relationship to the mammalian brain and highlights key questions that have yet to be answered.
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Affiliation(s)
| | - Eric N. Jimenez-Vazquez
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, United States
| | - David S. Auerbach
- Department of Pharmacology, State University of New York Upstate Medical University, Syracuse, NY, United States
- *Correspondence: David S. Auerbach,
| | - David K. Jones
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, United States
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI, United States
- David K. Jones,
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Krahn AD, Laksman Z, Sy RW, Postema PG, Ackerman MJ, Wilde AAM, Han HC. Congenital Long QT Syndrome. JACC Clin Electrophysiol 2022; 8:687-706. [PMID: 35589186 DOI: 10.1016/j.jacep.2022.02.017] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 02/16/2022] [Accepted: 02/16/2022] [Indexed: 12/14/2022]
Abstract
Congenital long QT syndrome (LQTS) encompasses a group of heritable conditions that are associated with cardiac repolarization dysfunction. Since its initial description in 1957, our understanding of LQTS has increased dramatically. The prevalence of LQTS is estimated to be ∼1:2,000, with a slight female predominance. The diagnosis of LQTS is based on clinical, electrocardiogram, and genetic factors. Risk stratification of patients with LQTS aims to identify those who are at increased risk of cardiac arrest or sudden cardiac death. Factors including age, sex, QTc interval, and genetic background all contribute to current risk stratification paradigms. The management of LQTS involves conservative measures such as the avoidance of QT-prolonging drugs, pharmacologic measures with nonselective β-blockers, and interventional approaches such as device therapy or left cardiac sympathetic denervation. In general, most forms of exercise are considered safe in adequately treated patients, and implantable cardioverter-defibrillator therapy is reserved for those at the highest risk. This review summarizes our current understanding of LQTS and provides clinicians with a practical approach to diagnosis and management.
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Affiliation(s)
- Andrew D Krahn
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada.
| | - Zachary Laksman
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada
| | - Raymond W Sy
- Faculty of Medicine and Health, The University of Sydney, Sydney, New South Wales, Australia
| | - Pieter G Postema
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - Michael J Ackerman
- Department of Cardiovascular Medicine, Division of Heart Rhythm Services, Windland Smith Rice Genetic Heart Rhythm Clinic, Mayo Clinic, Rochester, Minnesota, USA; Department of Pediatric and Adolescent Medicine, Division of Pediatric Cardiology, Mayo Clinic, Rochester, Minnesota, USA; Departments of Molecular Pharmacology and Experimental Therapeutics, Windland Smith Rice Sudden Death Genomics Laboratory, Mayo Clinic, Rochester, Minnesota, USA
| | - Arthur A M Wilde
- Department of Clinical and Experimental Cardiology, Heart Center, Amsterdam University Medical Centers, Amsterdam, the Netherlands; European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart (ERN GUARD-Heart), Academic University Medical Center, Amsterdam, the Netherlands
| | - Hui-Chen Han
- Center for Cardiovascular Innovation, Heart Rhythm Services, Division of Cardiology, University of British Columbia, Vancouver, BC, Canada; Victorian Heart Institute, Monash University, Clayton, VIC, Australia
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di Carlo KS, Cajat B. Crise comitiale et arrêt cardiaque secondaire à un syndrome du QT long. ANNALES FRANCAISES DE MEDECINE D URGENCE 2022. [DOI: 10.3166/afmu-2022-0386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Wenker IC, Blizzard EA, Wagley PK, Patel MK. Peri-Ictal Autonomic Control of Cardiac Function and Seizure-Induced Death. Front Neurosci 2022; 15:795145. [PMID: 35126041 PMCID: PMC8813980 DOI: 10.3389/fnins.2021.795145] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Accepted: 12/13/2021] [Indexed: 11/13/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) accounts for the deaths of 8–17% of patients with epilepsy. Although the mechanisms of SUDEP are unknown, one proposed mechanism is abnormal control of the heart by the autonomic nervous system (ANS). Our objective was to determine whether the broad changes in ictal heart rate experienced by mouse models of SUDEP are (1) due to the ANS and (2) contribute to seizure-induced death. Seizures were induced by electrical stimulation of the hippocampus of a mouse carrying the human SCN8A encephalopathy mutation p.Asn1768Asp (N1768D; “D/+ mice”). Using standard autonomic pharmacology, the relative roles of the parasympathetic and sympathetic nervous systems on heart rate changes associated with seizures were determined. All induced seizures had pronounced ictal bradycardia and postictal tachycardia. Seizure susceptibility or severity were unchanged by the pharmacological agents. Administration of Atropine, a muscarinic antagonist, eliminated ictal bradycardia, while carbachol, a muscarinic agonist, had no effect on ictal bradycardia, but reduced postictal tachycardia. Sotalol, an adrenergic β-receptor antagonist, had no effect on ictal bradycardia, but did suppress postictal tachycardia. Isoproterenol, a β-receptor agonist, had no effect on either ictal bradycardia or postictal tachycardia. Administration of the α1-receptor antagonist prazosin increases the incidence of seizure-induced death in D/+ mice. Although postictal heart rate was lower for these fatal seizures in the presence of prazosin, rates were not as low as that recorded for carbachol treated mice, which all survived. Both ictal bradycardia and postictal tachycardia are manifestations of the ANS. Bradycardia is mediated by a maximal activation of the parasympathetic arm of the ANS, and tachycardia is mediated by parasympathetic inactivation and sympathetic activation. While the changes in heart rate during seizures are profound, suppression of postictal heart rate did not increase seizure mortality.
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Autonomic manifestations of epilepsy: emerging pathways to sudden death? Nat Rev Neurol 2021; 17:774-788. [PMID: 34716432 DOI: 10.1038/s41582-021-00574-w] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/24/2021] [Indexed: 12/24/2022]
Abstract
Epileptic networks are intimately connected with the autonomic nervous system, as exemplified by a plethora of ictal (during a seizure) autonomic manifestations, including epigastric sensations, palpitations, goosebumps and syncope (fainting). Ictal autonomic changes might serve as diagnostic clues, provide targets for seizure detection and help us to understand the mechanisms that underlie sudden unexpected death in epilepsy (SUDEP). Autonomic alterations are generally more prominent in focal seizures originating from the temporal lobe, demonstrating the importance of limbic structures to the autonomic nervous system, and are particularly pronounced in focal-to-bilateral and generalized tonic-clonic seizures. The presence, type and severity of autonomic features are determined by the seizure onset zone, propagation pathways, lateralization and timing of the seizures, and the presence of interictal autonomic dysfunction. Evidence is mounting that not all autonomic manifestations are linked to SUDEP. In addition, experimental and clinical data emphasize the heterogeneity of SUDEP and its infrequent overlap with sudden cardiac death. Here, we review the spectrum and diagnostic value of the mostly benign and self-limiting autonomic manifestations of epilepsy. In particular, we focus on presentations that are likely to contribute to SUDEP and discuss how wearable devices might help to prevent SUDEP.
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Ton AT, Nguyen W, Sweat K, Miron Y, Hernandez E, Wong T, Geft V, Macias A, Espinoza A, Truong K, Rasoul L, Stafford A, Cotta T, Mai C, Indersmitten T, Page G, Miller PE, Ghetti A, Abi-Gerges N. Arrhythmogenic and antiarrhythmic actions of late sustained sodium current in the adult human heart. Sci Rep 2021; 11:12014. [PMID: 34103608 PMCID: PMC8187365 DOI: 10.1038/s41598-021-91528-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 05/27/2021] [Indexed: 12/19/2022] Open
Abstract
Late sodium current (late INa) inhibition has been proposed to suppress the incidence of arrhythmias generated by pathological states or induced by drugs. However, the role of late INa in the human heart is still poorly understood. We therefore investigated the role of this conductance in arrhythmias using adult primary cardiomyocytes and tissues from donor hearts. Potentiation of late INa with ATX-II (anemonia sulcata toxin II) and E-4031 (selective blocker of the hERG channel) slowed the kinetics of action potential repolarization, impaired Ca2+ homeostasis, increased contractility, and increased the manifestation of arrhythmia markers. These effects could be reversed by late INa inhibitors, ranolazine and GS-967. We also report that atrial tissues from donor hearts affected by atrial fibrillation exhibit arrhythmia markers in the absence of drug treatment and inhibition of late INa with GS-967 leads to a significant reduction in arrhythmic behaviour. These findings reveal a critical role for the late INa in cardiac arrhythmias and suggest that inhibition of this conductance could provide an effective therapeutic strategy. Finally, this study highlights the utility of human ex-vivo heart models for advancing cardiac translational sciences.
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Affiliation(s)
- Anh Tuan Ton
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - William Nguyen
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Katrina Sweat
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Yannick Miron
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Eduardo Hernandez
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Tiara Wong
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Valentyna Geft
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Andrew Macias
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Ana Espinoza
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Ky Truong
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Lana Rasoul
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Alexa Stafford
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Tamara Cotta
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Christina Mai
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Tim Indersmitten
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Guy Page
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Paul E Miller
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Andre Ghetti
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA
| | - Najah Abi-Gerges
- AnaBios Corporation, 3030 Bunker Hill St., Suite 312, San Diego, CA, 92109, USA.
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Mori S, Hori A, Turker I, Inaji M, Bello-Pardo E, Miida T, Otomo Y, Ai T. Abnormal Cardiac Repolarization After Seizure Episodes in Structural Brain Diseases: Cardiac Manifestation of Electrical Remodeling in the Brain? J Am Heart Assoc 2021; 10:e019778. [PMID: 33899505 PMCID: PMC8200721 DOI: 10.1161/jaha.120.019778] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Background Abnormal cardiac repolarization is observed in patients with epilepsy and can be associated with sudden death. We investigated whether structural brain abnormalities are correlated with abnormal cardiac repolarizations in patients with seizure or epilepsy. Methods and Results We retrospectively analyzed and compared 12‐lead ECG parameters following seizures between patients with and without structural brain abnormalities. A total of 96 patients were included: 33 women (17 with and 16 without brain abnormality) and 63 men (44 with and 19 without brain abnormality). Brain abnormalities included past stroke, chronic hematoma, remote bleeding, tumor, trauma, and postsurgical state. ECG parameters were comparable for heart rate, PR interval, and QRS duration between groups. In contrast, corrected QT intervals evaluated by Fridericia, Framingham, and Bazett formulas were prolonged in patients with brain abnormality compared with those without (women: Fridericia [normal versus abnormal], 397.4±32.7 versus 470.9±48.9; P=0.002; Framingham, 351.0±40.1 versus 406.2±46.1; P=0.002; Bazett, 423.8±38.3 versus 507.7±56.6; P<0.0001; men: Fridericia, 403.8±30.4 versus 471.0±47.1; P<0.0001; Framingham, 342.7±36.4 versus 409.4±45.8; P<0.0001; Bazett, 439.3±38.6 versus 506.2±56.8; P<0.0001). QT dispersion and Tpeak−Tend intervals were comparable between groups. We also observed abnormal ST‐segment elevation in 5 patients. Importantly, no patients showed fatal arrhythmias during or after seizures. Conclusions Our study demonstrated that brain abnormalities can be associated with abnormal cardiac repolarization after seizures, which might be a manifestation of electrophysiological remodeling in the brain.
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Affiliation(s)
- Shusuke Mori
- Department of Acute Critical Care and Disaster Medicine Tokyo Medical and Dental University Tokyo Japan
| | - Atsushi Hori
- Department of Clinical Laboratory Medicine Juntendo University Graduate School of Medicine Tokyo Japan
| | - Isik Turker
- Division of Cardiovascular Medicine Department of Medicine Vanderbilt University Medical Center Nashville TN
| | - Motoki Inaji
- Department of Neurosurgery Epilepsy Center Tokyo Medical and Dental University Tokyo Japan
| | - Erika Bello-Pardo
- Division of Human Genetics Department of Internal Medicine Ohio State University College of Medicine Columbus OH
| | - Takashi Miida
- Department of Clinical Laboratory Medicine Juntendo University Graduate School of Medicine Tokyo Japan
| | - Yasuhiro Otomo
- Department of Acute Critical Care and Disaster Medicine Tokyo Medical and Dental University Tokyo Japan
| | - Tomohiko Ai
- Department of Acute Critical Care and Disaster Medicine Tokyo Medical and Dental University Tokyo Japan.,Department of Clinical Laboratory Medicine Juntendo University Graduate School of Medicine Tokyo Japan.,Division of Human Genetics Department of Internal Medicine Ohio State University College of Medicine Columbus OH.,Department of Medicine Krannert Institute of Cardiology Indiana University School of Medicine Indianapolis IN
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14
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DeMaria N, Selmi A, Kashtan S, Xia X, Wang M, Zareba W, Couderc JP, Auerbach DS. Autonomic and Cardiac Repolarization Lability in Long QT Syndrome Patients. Auton Neurosci 2020; 229:102723. [PMID: 32942226 DOI: 10.1016/j.autneu.2020.102723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 08/24/2020] [Accepted: 08/31/2020] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Long QT-Syndrome (LQTS) patients are at risk of arrhythmias and seizures. We investigated whether autonomic and cardiac repolarization measures differed based on LQTS genotypes, and in LQTS patients with vs. without arrhythmias and seizures. METHODS We used 24-h ECGs from LQTS1 (n = 87), LQTS2 (n = 50), and LQTS genotype negative patients (LQTS(-), n = 16). Patients were stratified by LQTS genotype, and arrhythmias/seizures. Heart rate variability (HRV) and QT variability index (QTVI) measures were compared between groups during specific physiological states (minimum, middle, & maximum sympathovagal balance, LF/HF). Results were further tested using logistic regression for each ECG measure, and all HRV measures in a single multivariate model. RESULTS Across multiple physiological states, total autonomic (SDNN) and vagal (RMSSD, pNN50) function were lower and repolarization dynamics (QTVI) were elevated in LQTS(+), LQTS1, and LQTS2, compared to LQTS(-). Many measures remained significant in the regression models. Multivariate modeling demonstrated that SDNN, RMSSD, and pNN50 were independent markers of LQTS(+) vs. LQTS(-), and SDNN and pNN50 were markers for LQTS1 vs. LQTS(-). During sympathovagal balance (middle LF/HF), RMSSD and pNN50 distinguished LQTS1 vs. LQTS2. LQTS1 patients with arrhythmias had lower total (SDNN) and vagal (RMSSD and pNN50) autonomic function, and SDNN remained significant in the models. In contrast, ECG measures did not differ in LQTS2 patients with vs. without arrhythmias, and LQTS1 and LQTS2 with vs. without seizures. CONCLUSION Autonomic (HRV) and cardiac repolarization (QTVI) ECG measures differ based on LQTS genotype and history of arrhythmias in LQTS1. SDNN, RMSSD, and pNN50 were each independent markers for LQTS genotype.
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Affiliation(s)
- Natalia DeMaria
- Department of Pharmacology, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, United States
| | - Ahmed Selmi
- Biomedical Engineering, ,University of Rochester, P.O. Box 270076, Rochester, NY, United States
| | - Samuel Kashtan
- Biomedical Engineering, ,University of Rochester, P.O. Box 270076, Rochester, NY, United States
| | - Xiaojuan Xia
- Medicine-Clinical Cardiology Research Center, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States
| | - Matthew Wang
- Department of Pharmacology, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, United States
| | - Wojciech Zareba
- Medicine-Clinical Cardiology Research Center, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States
| | - Jean-Philippe Couderc
- Medicine-Clinical Cardiology Research Center, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States
| | - David S Auerbach
- Department of Pharmacology, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, United States; Medicine-Aab Cardiovascular Research Institute, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States; Pharmacology/Physiology, University of Rochester Medical Center, 601 Elmwood Ave, Rochester, NY, United States.
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15
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Pensel MC, Nass RD, Taubøll E, Aurlien D, Surges R. Prevention of sudden unexpected death in epilepsy: current status and future perspectives. Expert Rev Neurother 2020; 20:497-508. [PMID: 32270723 DOI: 10.1080/14737175.2020.1754195] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Introduction: Sudden unexpected death in epilepsy (SUDEP) affects about 1 in 1000 people with epilepsy, and even more in medically refractory epilepsy. As most people are between 20 and 40 years when dying suddenly, SUDEP leads to a considerable loss of potential life years. The most important risk factors are nocturnal and tonic-clonic seizures, underscoring that supervision and effective seizure control are key elements for SUDEP prevention. The question of whether specific antiepileptic drugs are linked to SUDEP is still controversially discussed. Knowledge and education about SUDEP among health-care professionals, patients, and relatives are of outstanding importance for preventive measures to be taken, but still poor and widely neglected.Areas covered: This article reviews epidemiology, pathophysiology, risk factors, assessment of individual SUDEP risk and available measures for SUDEP prevention. Literature search was done using Medline and Pubmed in October 2019.Expert opinion: Significant advances in the understanding of SUDEP were made in the last decade which allow testing of novel strategies to prevent SUDEP. Promising current strategies target neuronal mechanisms of brain stem dysfunction, cardiac susceptibility for fatal arrhythmias, and reliable detection of tonic-clonic seizures using mobile health technologies.Abbreviations: AED, antiepileptic drug; CBZ, carbamazepine; cLQTS, congenital long QT syndrome; EMU, epilepsy monitoring unit; FBTCS, focal to bilateral tonic-clonic seizures; GTCS, generalized tonic-clonic seizures; ICA, ictal central apnea; LTG, lamotrigine; PCCA, postconvulsive central apnea; PGES, postictal generalized EEG suppression; SRI, serotonin reuptake inhibitor; SUDEP, sudden unexpected death in epilepsy; TCS, tonic-clonic seizures.
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Affiliation(s)
| | | | - Erik Taubøll
- Department of Neurology, Oslo University Hospital, Nydalen, Norway.,Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Dag Aurlien
- Neuroscience Research Group and Department of Neurology, Stavanger University Hospital, Stavanger, Norway
| | - Rainer Surges
- Department of Epileptology, University Hospital Bonn, Bonn, Germany
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16
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Li R, Buchanan GF. Scurrying to Understand Sudden Expected Death in Epilepsy: Insights From Animal Models. Epilepsy Curr 2019; 19:390-396. [PMID: 31526023 PMCID: PMC6891182 DOI: 10.1177/1535759719874787] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in patients with refractory epilepsy, accounting for up to 17% of deaths in patients with epilepsy. The pathophysiology of SUDEP has remained unclear, largely because it is unpredictable and commonly unwitnessed. This poses a great challenge to studies in patients. Recently, there has been an increase in animal studies to try to better understand the pathophysiology of SUDEP. In this current review, we focus on developments through seizure-induced death models and the preventative strategies they may reveal.
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Affiliation(s)
- Rui Li
- Department of Neurology, Carver College of Medicine, University of Iowa, IA, USA
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, IA, USA
| | - Gordon F. Buchanan
- Department of Neurology, Carver College of Medicine, University of Iowa, IA, USA
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, IA, USA
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17
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Marstrand P, Theilade J, Andersson C, Bundgaard H, Weeke PE, Tfelt-Hansen J, Jespersen C, Gislason G, Torp-Pedersen C, Kanters JK, Jørgensen ME. Long QT syndrome is associated with an increased burden of diabetes, psychiatric and neurological comorbidities: a nationwide cohort study. Open Heart 2019; 6:e001161. [PMID: 31749975 PMCID: PMC6827808 DOI: 10.1136/openhrt-2019-001161] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/03/2019] [Accepted: 10/08/2019] [Indexed: 12/19/2022] Open
Abstract
Objective Studies have suggested a shared genetic aetiology between congenital long QT syndrome (LQTS) and diabetes, epilepsy and mental disorders. We investigated the prevalence of metabolic, neurological and psychiatric comorbidities in LQTS patients. Methods This retrospective cohort study was based on data from nationwide Danish registries, 2003-2017. LQTS patients were matched 1:5 with controls on sex and age. Results We matched 463 LQTS patients with 2315 controls from the background population. Mean age was 35.7 (SD 21.0) years, and 38% were males in both groups. LQTS patients had a higher prevalence of atrial fibrillation (6.5% vs 2.3%, p<0.001), diabetes (3.7% vs 1.8 %, p=0.011) and hearing loss (3.2% vs 1.7%, p=0.027). LQTS patients had a higher prevalence of psychiatric disorders overall (13.0% vs 9.1%, p=0.01) but the difference could not be attributed to a specific psychiatric disease subgroup. LQTS patients had a higher prevalence of neurological disorders (22.0% vs 13.2%, p<0.001), largely driven by epilepsy (6.7% vs 1.6%, p<0.001). In 20/27 (74%) of the LQTS patients, the epilepsy diagnosis did not reappear in the registries after the LQTS diagnosis was established. Conclusions In this nationwide cohort, patients with LQTS had a significantly increased burden of diabetes, neurological and psychiatric comorbidities, compared with the background population. The higher prevalence of neurological comorbidities was largely driven by epilepsy, despite a high rate of potentially misdiagnosed patients prior to LQTS diagnosis. Our data support that LQTS may be considered a multiorgan disease and suggest that patient management should be adjusted accordingly.
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Affiliation(s)
- Peter Marstrand
- Department of Cardiology, Herlev-Gentofte Hospital, University Hospital of Copenhagen, Copenhagen, Denmark
| | - Juliane Theilade
- Department of Cardiology, Herlev-Gentofte Hospital, University Hospital of Copenhagen, Copenhagen, Denmark
| | - Charlotte Andersson
- Department of Cardiology, Herlev-Gentofte Hospital, University Hospital of Copenhagen, Copenhagen, Denmark
| | - Henning Bundgaard
- Department of Cardiology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
| | - Peter E Weeke
- Department of Cardiology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
| | - Jacob Tfelt-Hansen
- Department of Cardiology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark.,Department of Forensic Medicine, Faculty of Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Camilla Jespersen
- Department of Cardiology, Rigshospitalet, University Hospital Copenhagen, Copenhagen, Denmark
| | - Gunnar Gislason
- Department of Cardiology, Herlev-Gentofte Hospital, University Hospital of Copenhagen, Copenhagen, Denmark
| | - Christian Torp-Pedersen
- Department of Health, Science and Technology, Aalborg University and Departments of Cardiology and Biostatistics/epidemiology, Aalborg University Hospital, Aalborg, Denmark
| | - Jørgen K Kanters
- Laboratory of Experimental Cardiology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Mads E Jørgensen
- Department of Cardiology, Herlev-Gentofte Hospital, University Hospital of Copenhagen, Copenhagen, Denmark
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18
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Li MCH, O'Brien TJ, Todaro M, Powell KL. Acquired cardiac channelopathies in epilepsy: Evidence, mechanisms, and clinical significance. Epilepsia 2019; 60:1753-1767. [PMID: 31353444 DOI: 10.1111/epi.16301] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 07/07/2019] [Accepted: 07/07/2019] [Indexed: 12/13/2022]
Abstract
There is growing evidence that cardiac dysfunction in patients with chronic epilepsy could play a pathogenic role in sudden unexpected death in epilepsy (SUDEP). Recent animal studies have revealed that epilepsy secondarily alters the expression of cardiac ion channels alongside abnormal cardiac electrophysiology and remodeling. These molecular findings represent novel evidence for an acquired cardiac channelopathy in epilepsy, distinct from inherited ion channels mutations associated with cardiocerebral phenotypes. Specifically, seizure activity has been shown to alter the messenger RNA (mRNA) and protein expression of voltage-gated sodium channels (Nav 1.1, Nav 1.5), voltage-gated potassium channels (Kv 4.2, Kv 4.3), sodium-calcium exchangers (NCX1), and nonspecific cation-conducting channels (HCN2, HCN4). The pathophysiology may involve autonomic dysfunction and structural cardiac disease, as both are independently associated with epilepsy and ion channel dysregulation. Indeed, in vivo and in vitro studies of cardiac pathology reveal a complex network of signaling pathways and transcription factors regulating ion channel expression in the setting of sympathetic overactivity, cardiac failure, and hypertrophy. Other mechanisms such as circulating inflammatory mediators or exogenous effects of antiepileptic medications lack evidence. Moreover, an acquired cardiac channelopathy may underlie the electrophysiologic cardiac abnormalities seen in chronic epilepsy, potentially contributing to the increased risk of malignant arrhythmias and sudden death. Therefore, further investigation is necessary to establish whether cardiac ion channel dysregulation similarly occurs in patients with epilepsy, and to characterize any pathogenic relationship with SUDEP.
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Affiliation(s)
- Michael C H Li
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Marian Todaro
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia.,Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Kim L Powell
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
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19
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Prüss H, Gessner G, Heinemann SH, Rüschendorf F, Ruppert AK, Schulz H, Sander T, Rimpau W. Linkage Evidence for a Two-Locus Inheritance of LQT-Associated Seizures in a Multigenerational LQT Family With a Novel KCNQ1 Loss-of-Function Mutation. Front Neurol 2019; 10:648. [PMID: 31293497 PMCID: PMC6603176 DOI: 10.3389/fneur.2019.00648] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Accepted: 06/03/2019] [Indexed: 12/21/2022] Open
Abstract
Mutations in several genes encoding ion channels can cause the long-QT (LQT) syndrome with cardiac arrhythmias, syncope and sudden death. Recently, mutations in some of these genes were also identified to cause epileptic seizures in these patients, and the sudden unexplained death in epilepsy (SUDEP) was considered to be the pathologic overlap between the two clinical conditions. For LQT-associated KCNQ1 mutations, only few investigations reported the coincidence of cardiac dysfunction and epileptic seizures. Clinical, electrophysiological and genetic characterization of a large pedigree (n = 241 family members) with LQT syndrome caused by a 12-base-pair duplication in exon 8 of the KCNQ1 gene duplicating four amino acids in the carboxyterminal KCNQ1 domain (KCNQ1dup12; p.R360_Q361dupQKQR, NM_000218.2, hg19). Electrophysiological recordings revealed no substantial KCNQ1-like currents. The mutation did not exhibit a dominant negative effect on wild-type KCNQ1 channel function. Most likely, the mutant protein was not functionally expressed and thus not incorporated into a heteromeric channel tetramer. Many LQT family members suffered from syncopes or developed sudden death, often after physical activity. Of 26 family members with LQT, seizures were present in 14 (LQTplus seizure trait). Molecular genetic analyses confirmed a causative role of the novel KCNQ1dup12 mutation for the LQT trait and revealed a strong link also with the LQTplus seizure trait. Genome-wide parametric multipoint linkage analyses identified a second strong genetic modifier locus for the LQTplus seizure trait in the chromosomal region 10p14. The linkage results suggest a two-locus inheritance model for the LQTplus seizure trait in which both the KCNQ1dup12 mutation and the 10p14 risk haplotype are necessary for the occurrence of LQT-associated seizures. The data strongly support emerging concepts that KCNQ1 mutations may increase the risk of epilepsy, but additional genetic modifiers are necessary for the clinical manifestation of epileptic seizures.
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Affiliation(s)
- Harald Prüss
- Department of Neurology and Experimental Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.,German Center for Neurodegenerative Diseases (DZNE) Berlin, Bonn, Germany
| | - Guido Gessner
- Department of Biophysics, Center for Molecular Biomedicine, Friedrich Schiller University Jena & Jena University Hospital, Jena, Germany
| | - Stefan H Heinemann
- Department of Biophysics, Center for Molecular Biomedicine, Friedrich Schiller University Jena & Jena University Hospital, Jena, Germany
| | | | | | - Herbert Schulz
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Thomas Sander
- Cologne Center for Genomics, University of Cologne, Cologne, Germany
| | - Wilhelm Rimpau
- Department of Neurology and Experimental Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
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20
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González A, Aurlien D, Larsson PG, Olsen KB, Dahl IT, Edvardsen T, Haugaa KH, Taubøll E. Seizure-like episodes and EEG abnormalities in patients with long QT syndrome. Seizure 2018; 61:214-220. [DOI: 10.1016/j.seizure.2018.08.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 07/13/2018] [Accepted: 08/25/2018] [Indexed: 01/05/2023] Open
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21
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Zarroli K, Querfurth H. New onset seizures in a patient with Long QT Syndrome (LQTS2) and a pathogenic carboxyl-terminus frameshift variant of the KCNH2 gene. J Clin Neurosci 2018; 53:253-255. [DOI: 10.1016/j.jocn.2018.04.040] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2018] [Accepted: 04/22/2018] [Indexed: 11/25/2022]
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22
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Genetic biomarkers for the risk of seizures in long QT syndrome. Neurology 2018; 90:1127. [DOI: 10.1212/wnl.0000000000005659] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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23
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Auerbach DS, Biton Y, Polonsky B, McNitt S, Gross RA, Dirksen RT, Moss AJ. Risk of cardiac events in Long QT syndrome patients when taking antiseizure medications. Transl Res 2018; 191:81-92.e7. [PMID: 29121487 PMCID: PMC5733703 DOI: 10.1016/j.trsl.2017.10.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 10/02/2017] [Accepted: 10/07/2017] [Indexed: 12/29/2022]
Abstract
Many antiseizure medications (ASMs) affect ion channel function. We investigated whether ASMs alter the risk of cardiac events in patients with corrected QT (QTc) prolongation. The study included people from the Rochester-based Long QT syndrome (LQTS) Registry with baseline QTc prolongation and history of ASM therapy (n = 296). Using multivariate Anderson-Gill models, we assessed the risk of recurrent cardiac events associated with ASM therapy. We stratified by LQTS genotype and predominant mechanism of ASM action (Na+ channel blocker and gamma-aminobutyric acid modifier.) There was an increased risk of cardiac events when participants with QTc prolongation were taking vs off ASMs (HR 1.65, 95% confidence interval [CI] 1.36-2.00, P < 0.001). There was an increased risk of cardiac events when LQTS2 (HR 1.49, 95% CI 1.03-2.15, P = 0.036) but not LQTS1 participants were taking ASMs (interaction, P = 0.016). Na+ channel blocker ASMs were associated with an increased risk of cardiac events in participants with QTc prolongation, specifically LQTS2, but decreased risk in LQTS1. The increased risk when taking all ASMs and Na+ channel blocker ASMs was attenuated by concurrent beta-adrenergic blocker therapy (interaction, P < 0.001). Gamma-aminobutyric acid modifier ASMs were associated with an increased risk of events in patients not concurrently treated with beta-adrenergic blockers. Female participants were at an increased risk of cardiac events while taking all ASMs and each class of ASMs. Despite no change in overall QTc duration, pharmacogenomic analyses set the stage for future prospective clinical and mechanistic studies to validate that ASMs with predominantly Na+ channel blocking actions are deleterious in LQTS2, but protective in LQTS1.
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Affiliation(s)
- David S Auerbach
- Department of Medicine, Aab Cardiovascular Research Institute, University of Rochester School of Medicine and Dentistry, Rochester, NY; Department of Pharmacology & Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY.
| | - Yitschak Biton
- Department of Medicine, Heart Research Follow up Program, University of Rochester School of Medicine and Dentistry, Rochester, NY; Department of Cardiology, Massachusetts General Hospital and Harvard Medical School, Boston, Mass
| | - Bronislava Polonsky
- Department of Medicine, Heart Research Follow up Program, University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - Scott McNitt
- Department of Medicine, Heart Research Follow up Program, University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - Robert A Gross
- Department of Pharmacology & Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY; Department of Neurology, University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - Robert T Dirksen
- Department of Pharmacology & Physiology, University of Rochester School of Medicine and Dentistry, Rochester, NY
| | - Arthur J Moss
- Department of Medicine, Heart Research Follow up Program, University of Rochester School of Medicine and Dentistry, Rochester, NY
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24
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Vanhoof-Villalba SL, Gautier NM, Mishra V, Glasscock E. Pharmacogenetics of KCNQ channel activation in 2 potassium channelopathy mouse models of epilepsy. Epilepsia 2017; 59:358-368. [PMID: 29265344 DOI: 10.1111/epi.13978] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2017] [Indexed: 01/05/2023]
Abstract
OBJECTIVES Antiseizure drugs are the leading therapeutic choice for treatment of epilepsy, but their efficacy is limited by pharmacoresistance and the occurrence of unwanted side effects. Here, we examined the therapeutic efficacy of KCNQ channel activation by retigabine in preventing seizures and neurocardiac dysfunction in 2 potassium channelopathy mouse models of epilepsy with differing severity that have been associated with increased risk of sudden unexpected death in epilepsy (SUDEP): the Kcna1-/- model of severe epilepsy and the Kcnq1A340E/A340E model of mild epilepsy. METHODS A combination of behavioral, seizure threshold, electrophysiologic, and gene expression analyses was used to determine the effects of KCNQ activation in mice. RESULTS Behaviorally, Kcna1-/- mice exhibited unexpected hyperexcitability instead of the expected sedative-like response. In flurothyl-induced seizure tests, KCNQ activation decreased seizure latency by ≥50% in Kcnq1 strain mice but had no effect in the Kcna1 strain, suggesting the influence of genetic background. However, in simultaneous electroencephalography and electrocardiography recordings, KCNQ activation significantly reduced spontaneous seizure frequency in Kcna1-/- mice by ~60%. In Kcnq1A340E/A340E mice, KCNQ activation produced adverse cardiac effects including profound bradycardia and abnormal increases in heart rate variability and atrioventricular conduction blocks. Analyses of Kcnq2 and Kcnq3 mRNA levels revealed significantly elevated Kcnq2 expression in Kcna1-/- brains, suggesting that drug target alterations may contribute to the altered drug responses. SIGNIFICANCE This study shows that treatment strategies in channelopathy may have unexpected outcomes and that effective rebalancing of channel defects requires improved understanding of channel interactions at the circuit and tissue levels. The efficacy of KCNQ channel activation and manifestation of adverse effects were greatly affected by genetic background, potentially limiting KCNQ modulation as a way to prevent neurocardiac dysfunction in epilepsy and thereby SUDEP risk. Our data also uncover a potential role for KCNQ2-5 channels in autonomic control of chronotropy.
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Affiliation(s)
- Stephanie L Vanhoof-Villalba
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Nicole M Gautier
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Vikas Mishra
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Edward Glasscock
- Department of Cellular Biology and Anatomy, Louisiana State University Health Sciences Center, Shreveport, LA, USA
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25
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Bagnall RD, Crompton DE, Semsarian C. Genetic Basis of Sudden Unexpected Death in Epilepsy. Front Neurol 2017; 8:348. [PMID: 28775708 PMCID: PMC5517398 DOI: 10.3389/fneur.2017.00348] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Accepted: 07/03/2017] [Indexed: 11/13/2022] Open
Abstract
People with epilepsy are at heightened risk of sudden death compared to the general population. The leading cause of epilepsy-related premature mortality is sudden unexpected death in epilepsy (SUDEP). Postmortem investigation of people with SUDEP, including histological and toxicological analysis, does not reveal a cause of death, and the mechanisms of SUDEP remain largely unresolved. In this review we present the possible mechanisms underlying SUDEP, including respiratory dysfunction, cardiac arrhythmia and postictal generalized electroencephlogram suppression. Emerging studies in humans and animal models suggest there may be an underlying genetic basis to SUDEP in some cases. We will highlight a mounting body of evidence for the involvement of genetic risk factors in SUDEP, with a particular focus on the role of cardiac arrhythmia genes in SUDEP.
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Affiliation(s)
- Richard D Bagnall
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, NSW, Australia.,Sydney Medical School, University of Sydney, Sydney, NSW, Australia
| | - Douglas E Crompton
- Department of Neurology, Northern Health, Melbourne, VIC, Australia.,Epilepsy Research Centre, Department of Medicine, University of Melbourne, Austin Health, Melbourne, VIC, Australia
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, NSW, Australia.,Sydney Medical School, University of Sydney, Sydney, NSW, Australia.,Department of Cardiology, Royal Prince Alfred Hospital, Sydney, NSW, Australia
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26
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Madan N, Carvalho KS. Neurological Complications of Cardiac Disease. Semin Pediatr Neurol 2017; 24:3-13. [PMID: 28779863 DOI: 10.1016/j.spen.2017.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This article focuses on the complex interactions between the cardiovascular and neurologic systems. Initially, we focus on neurological complications in children with congenital heart disease both secondary to the underlying cardiac disease and complications of interventions. We later discuss diagnosis and management of common syncope syndromes with emphasis on vasovagal syncope. We also review the diagnosis, classification, and management of children and adolescents with postural orthostatic tachycardia syndrome. Lastly, we discuss long QT syndrome and sudden unexpected death in epilepsy (SUDEP), reviewing advances in genetics and current knowledge of pathophysiology of these conditions. This article attempts to provide an overview of these disorders with focus on pathophysiology, advances in molecular genetics, and current medical interventions.
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Affiliation(s)
- Nandini Madan
- From the Section of Cardiology, Department of Pediatrics, St. Christopher's Hospital for Children, Drexel University College of Medicine, Philadelphia, PA.
| | - Karen S Carvalho
- Section of Neurology, Department of Pediatrics, St. Christopher's Hospital for Children, Drexel University College of Medicine, Philadelphia, PA
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27
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The heart of epilepsy: Current views and future concepts. Seizure 2016; 44:176-183. [PMID: 27843098 DOI: 10.1016/j.seizure.2016.10.001] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Accepted: 10/03/2016] [Indexed: 12/16/2022] Open
Abstract
Cardiovascular (CV) comorbidities are common in people with epilepsy. Several mechanisms explain why these conditions tend to co-exist including causal associations, shared risk factors and those resulting from epilepsy or its treatment. Various arrhythmias occurring during and after seizures have been described. Ictal asystole is the most common cause. The converse phenomenon, arrhythmias causing seizures, appears extremely rare and has only been reported in children following cardioinihibitory syncope. Arrhythmias in epilepsy may not only result from seizure activity but also from a shared genetic susceptibility. Various cardiac and epilepsy genes could be implicated but firm evidence is still lacking. Several antiepileptic drugs (AEDs) triggering conduction abnormalities can also explain the co-existence of arrhythmias in epilepsy. Epidemiological studies have consistently shown that people with epilepsy have a higher prevalence of structural cardiac disease and a poorer CV risk profile than those without epilepsy. Shared CV risk factors, genetics and etiological factors can account for a significant part of the relationship between epilepsy and structural cardiac disease. Seizure activity may cause transient myocardial ischaemia and the Takotsubo syndrome. Additionally, certain AEDs may themselves negatively affect CV risk profile in epilepsy. Here we discuss the fascinating borderland of epilepsy and cardiovascular conditions. The review focuses on epidemiology, clinical presentations and possible mechanisms for shared pathophysiology. It concludes with a discussion of future developments and a call for validated screening instruments and guidelines aiding the early identification and treatment of CV comorbidity in epilepsy.
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