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Acedo Reina E, Germany Morrison E, Dereli AS, Collard E, Raffoul R, Nonclercq A, El Tahry R. Vagus nerve electroneurogram-based detection of acute kainic acid induced seizures. Front Neurosci 2024; 18:1427308. [PMID: 39170680 PMCID: PMC11335647 DOI: 10.3389/fnins.2024.1427308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Accepted: 07/02/2024] [Indexed: 08/23/2024] Open
Abstract
Seizures produce autonomic symptoms, mainly sympathetic but also parasympathetic in origin. Within this context, the vagus nerve is a key player as it carries information from the different organs to the brain and vice versa. Hence, exploiting vagal neural traffic for seizure detection might be a promising tool to improve the efficacy of closed-loop Vagus Nerve Stimulation. This study developed a VENG detection algorithm that effectively detects seizures by emphasizing the loss of spontaneous rhythmicity associated with respiration in acute intrahippocampal Kainic Acid rat model. Among 20 induced seizures in six anesthetized rats, 13 were detected (sensitivity: 65%, accuracy: 92.86%), with a mean VENG-detection delay of 25.3 ± 13.5 s after EEG-based seizure onset. Despite variations in detection parameters, 7 out of 20 seizures exhibited no ictal VENG modifications and remained undetected. Statistical analysis highlighted a significant difference in Delta, Theta and Beta band evolution between detected and undetected seizures, in addition to variations in the magnitude of HR changes. Binomial logistic regression analysis confirmed that an increase in delta and theta band activity was associated with a decreased likelihood of seizure detection. This results suggest the possibility of distinct seizure spreading patterns between the two groups which may results in differential activation of the autonomic central network. Despite notable progress, limitations, particularly the absence of respiration recording, underscore areas for future exploration and refinement in closed-loop stimulation strategies for epilepsy management. This study constitutes the initial phase of a longitudinal investigation, which will subsequently involve reproducing these experiments in awake conditions with spontaneous recurrent seizures.
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Affiliation(s)
- Elena Acedo Reina
- Clinical Neuroscience, Institute of Neuroscience (IoNS), Université Catholique de Louvain, Brussels, Belgium
| | - Enrique Germany Morrison
- Clinical Neuroscience, Institute of Neuroscience (IoNS), Université Catholique de Louvain, Brussels, Belgium
- Walloon Excellence in Life Sciences and Biotechnology (WELBIO) Department, WEL Research Institute, Wavre, Belgium
| | - Ayse S. Dereli
- Clinical Neuroscience, Institute of Neuroscience (IoNS), Université Catholique de Louvain, Brussels, Belgium
| | - Elise Collard
- Clinical Neuroscience, Institute of Neuroscience (IoNS), Université Catholique de Louvain, Brussels, Belgium
| | - Romain Raffoul
- BEAMS Department, Université Libre de Bruxelles, Brussels, Belgium
| | | | - Riëm El Tahry
- Clinical Neuroscience, Institute of Neuroscience (IoNS), Université Catholique de Louvain, Brussels, Belgium
- Walloon Excellence in Life Sciences and Biotechnology (WELBIO) Department, WEL Research Institute, Wavre, Belgium
- Department of Neurology, Center for Refractory Epilepsy, Cliniques Universitaires Saint-Luc, Brussels, Belgium
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George AG, Federico A, Gom RC, Harris SA, Teskey GC. Caffeine exacerbates seizure-induced death via postictal hypoxia. Sci Rep 2023; 13:14150. [PMID: 37644198 PMCID: PMC10465499 DOI: 10.1038/s41598-023-41409-6] [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: 03/22/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading epilepsy-related cause of premature mortality in people with intractable epilepsy, who are 27 times more likely to die than the general population. Impairment of the central control of breathing following a seizure has been identified as a putative cause of death, but the mechanisms underlying this seizure-induced breathing failure are largely unknown. Our laboratory has advanced a vascular theory of postictal behavioural dysfunction, including SUDEP. We have recently reported that seizure-induced death occurs after seizures invade brainstem breathing centres which then leads to local hypoxia causing breathing failure and death. Here we investigated the effects of caffeine and two adenosine receptors in two models of seizure-induced death. We recorded local oxygen levels in brainstem breathing centres as well as time to cessation of breathing and cardiac activity relative to seizure activity. The administration of the non-selective A1/A2A antagonist caffeine or the selective A1 agonist N6-cyclopentyladenosine reveals a detrimental effect on postictal hypoxia, providing support for caffeine modulating cerebral vasculature leading to brainstem hypoxia and cessation of breathing. Conversely, A2A activation with CGS-21680 was found to increase the lifespan of mice in both our models of seizure-induced death.
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Affiliation(s)
- Antis G George
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada.
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, Canada.
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada.
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, 3330 Hospital Drive N.W. Calgary, Alberta, T2N 4N, Canada.
| | - Alyssa Federico
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Clinical Neurosciences, University of Calgary, Calgary, AB, Canada
| | - Renaud C Gom
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, Canada
| | - Sydney A Harris
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - G Campbell Teskey
- Cumming School of Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, T2N 4N1, Canada
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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3
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Chinardet P, Gilles F, Cochet H, Chelly J, Quenot JP, Jacq G, Soulier P, Lesieur O, Beuret P, Holleville M, Bruel C, Bailly P, Sauneuf B, Sejourne C, Galbois A, Fontaine C, Perier F, Pichon N, Arrayago M, Mongardon N, Schnell D, Lascarrou JB, Convers R, Legriel S. Electrocardiographic Changes at the Early Stage of Status Epilepticus: First Insights From the ICTAL Registry. Crit Care Med 2023; 51:388-400. [PMID: 36533915 DOI: 10.1097/ccm.0000000000005768] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVES To describe early electrocardiogram (ECG) abnormalities after status epilepticus (SE) and evaluate their association with 90-day neurological outcomes. DESIGN Retrospective analysis of a multicenter, national prospective registry between February 2018 and June 2020. SETTING Sixteen ICUs in France, IctalGroup Research Network. PATIENTS Adults with available ECG performed less than or equal to 24 hours after the onset of SE and less than or equal to 12 hours after its resolution. INTERVENTION Double-blinded review of all ECGs was performed by two independent cardiologists. ECGs were categorized as normal/abnormal and then with minor/major early ECG abnormalities according to the Novacode ECG Classification system. MEASUREMENTS AND MAIN RESULTS Among 155 critically ill patients with SE, early ECG abnormalities were encountered in 145 (93.5%), categorized as major in 91 of 145 (62.8%). In addition to sinus tachycardia, the main abnormalities were in the ST segment (elevation [16.6%] or depression [17.9%]) or negative T waves (42.1%). Major early ECG abnormalities were significantly associated with respiratory distress and sinus tachycardia at the scene and hyperlactatemia at ICU admission. By multivariable analysis, three variables were significantly associated with 90-day poor outcome: age, preexisting ultimately fatal comorbidity, and cerebral insult as the cause of SE. Early major ECG abnormalities were not independently associated with 90-day functional outcome. CONCLUSIONS In our study, early ECG abnormalities in the acute phase of SE were frequent, often unrecognized and were associated with clinical and biological stigma of hypoxemia. Although they were not independently associated with 90-day functional outcome, ECG changes at the early stage of SE should be systematically evaluated. TRIAL REGISTRATION https://clinicaltrials.gov/ct2/show/NCT03457831 .
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Affiliation(s)
- Paul Chinardet
- Medical-Surgical Intensive Care Unit, Centre Hospitalier de Versailles - Site André Mignot, Le Chesnay Cedex, France
| | - Floriane Gilles
- Cardiology Department, Centre Hospitalier de Versailles - Site André Mignot, Le Chesnay Cedex, France
| | - Helene Cochet
- Cardiology Department, Centre Hospitalier de Versailles - Site André Mignot, Le Chesnay Cedex, France
| | - Jonathan Chelly
- IctalGroup, Le Chesnay, France
- Intensive Care Unit, Centre Hospitalier Intercommunal Toulon La Seyne sur Mer, Toulon, France
| | - Jean-Pierre Quenot
- IctalGroup, Le Chesnay, France
- Department of Intensive Care, François Mitterrand University Hospital, Dijon, France
| | - Gwenaelle Jacq
- Medical-Surgical Intensive Care Unit, Centre Hospitalier de Versailles - Site André Mignot, Le Chesnay Cedex, France
- IctalGroup, Le Chesnay, France
- UVSQ, INSERM, University Paris-Saclay, CESP, Team «PsyDev», Villejuif, France
| | - Pauline Soulier
- IctalGroup, Le Chesnay, France
- Intensive Care Unit, Marc Jacquet Hospital, Melun, France
| | - Olivier Lesieur
- IctalGroup, Le Chesnay, France
- Intensive Care Unit, Saint-Louis Hospital, La Rochelle, France
| | - Pascal Beuret
- IctalGroup, Le Chesnay, France
- Department of Intensive and Continuous Care, Roanne Hospital, Roanne, France
| | - Mathilde Holleville
- IctalGroup, Le Chesnay, France
- Department of Anesthesiology and Critical Care, Beaujon Hospital, DMU Parabol, Paris, France
| | - Cedric Bruel
- IctalGroup, Le Chesnay, France
- Saint Joseph Hospital, Medical-Surgical Intensive Care Unit, Paris, France
| | - Pierre Bailly
- IctalGroup, Le Chesnay, France
- Medical Intensive Care Unit, University Hospital of Brest, Cavale Blanche, Brest Cedex, France
| | - Bertrand Sauneuf
- IctalGroup, Le Chesnay, France
- Cotentin Public Hospital Center, General Intensive Care Unit, Cherbourg-en-Cotentin, France
| | - Caroline Sejourne
- IctalGroup, Le Chesnay, France
- Intensive Care Unit, Hôpital de Béthune, Beuvry, France
| | - Arnaud Galbois
- IctalGroup, Le Chesnay, France
- Department of Polyvalent Intensive Care Unit, Ramsay Générale de Santé, Claude Galien Private Hospital, Quincy-sous-Sénart, France
| | - Candice Fontaine
- Medical-Surgical Intensive Care Unit, Centre Hospitalier de Versailles - Site André Mignot, Le Chesnay Cedex, France
- IctalGroup, Le Chesnay, France
| | - François Perier
- Medical-Surgical Intensive Care Unit, Centre Hospitalier de Versailles - Site André Mignot, Le Chesnay Cedex, France
- IctalGroup, Le Chesnay, France
| | - Nicolas Pichon
- IctalGroup, Le Chesnay, France
- Intensive Care Unit, Centre Hospitalier de Brive, Brive-La-Gaillarde, France
| | - Marine Arrayago
- IctalGroup, Le Chesnay, France
- Department of Intensive Care, Cannes Hospital, Cannes, France
| | - Nicolas Mongardon
- IctalGroup, Le Chesnay, France
- Henri Mondor Teaching Hospital, Service D'anesthésie-Réanimation Chirurgicale, DMU CARE, DHU A-TVB, Assistance Publique-Hôpitaux de Paris (AP-HP), Univ Paris Est Créteil, Faculté de Santé, Créteil, France
- U955-IMRB, Equipe 03 "Pharmacologie Et Technologies Pour Les Maladies Cardiovasculaires (PROTECT)," Inserm, Univ Paris Est Créteil (UPEC), Ecole Nationale Vétérinaire d'Alfort (EnVA), Maisons-Alfort, France
| | - David Schnell
- IctalGroup, Le Chesnay, France
- Intensive Care Unit, Centre Hospitalier d'Angoulême, Angoulême, France
| | - Jean-Baptiste Lascarrou
- IctalGroup, Le Chesnay, France
- Intensive Care Unit, Centre Hospitalier Universitaire Hôtel-Dieu, Nantes Cedex, France
| | - Raphaële Convers
- Cardiology Department, Centre Hospitalier de Versailles - Site André Mignot, Le Chesnay Cedex, France
| | - Stephane Legriel
- Medical-Surgical Intensive Care Unit, Centre Hospitalier de Versailles - Site André Mignot, Le Chesnay Cedex, France
- IctalGroup, Le Chesnay, France
- UVSQ, INSERM, University Paris-Saclay, CESP, Team «PsyDev», Villejuif, France
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Fukushi I, Ikeda K, Takeda K, Yoshizawa M, Kono Y, Hasebe Y, Pokorski M, Okada Y. Minocycline prevents hypoxia-induced seizures. Front Neural Circuits 2023; 17:1006424. [PMID: 37035503 PMCID: PMC10073501 DOI: 10.3389/fncir.2023.1006424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Accepted: 02/27/2023] [Indexed: 04/11/2023] Open
Abstract
Severe hypoxia induces seizures, which reduces ventilation and worsens the ictal state. It is a health threat to patients, particularly those with underlying hypoxic respiratory pathologies, which may be conducive to a sudden unexpected death in epilepsy (SUDEP). Recent studies provide evidence that brain microglia are involved with both respiratory and ictal processes. Here, we investigated the hypothesis that microglia could interact with hypoxia-induced seizures. To this end, we recorded electroencephalogram (EEG) and acute ventilatory responses to hypoxia (5% O2 in N2) in conscious, spontaneously breathing adult mice. We compared control vehicle pre-treated animals with those pre-treated with minocycline, an inhibitory modulator of microglial activation. First, we histologically confirmed that hypoxia activates microglia and that pre-treatment with minocycline blocks hypoxia-induced microglial activation. Then, we analyzed the effects of minocycline pre-treatment on ventilatory responses to hypoxia by plethysmography. Minocycline alone failed to affect respiratory variables in room air or the initial respiratory augmentation in hypoxia. The comparative results showed that hypoxia caused seizures, which were accompanied by the late phase ventilatory suppression in all but one minocycline pre-treated mouse. Compared to the vehicle pre-treated, the minocycline pre-treated mice showed a delayed occurrence of seizures. Further, minocycline pre-treated mice tended to resist post-ictal respiratory arrest. These results suggest that microglia are conducive to seizure activity in severe hypoxia. Thus, inhibition of microglial activation may help suppress or prevent hypoxia-induced ictal episodes.
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Affiliation(s)
- Isato Fukushi
- Faculty of Health Sciences, Aomori University of Health and Welfare, Aomori, Japan
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- *Correspondence: Isato Fukushi
| | - Keiko Ikeda
- Homeostatic Mechanism Research Unit, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Faculty of Rehabilitation, School of Health Sciences, Fujita Health University, Toyoake, Japan
| | - Masashi Yoshizawa
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | - Yosuke Kono
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | - Yohei Hasebe
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
- Department of Pediatrics, Faculty of Medicine, University of Yamanashi, Chuo, Japan
| | | | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
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5
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Joyal KG, Kreitlow BL, Buchanan GF. The role of sleep state and time of day in modulating breathing in epilepsy: implications for sudden unexpected death in epilepsy. Front Neural Circuits 2022; 16:983211. [PMID: 36082111 PMCID: PMC9445500 DOI: 10.3389/fncir.2022.983211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 07/25/2022] [Indexed: 11/13/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among patients with refractory epilepsy. While the exact etiology of SUDEP is unknown, mounting evidence implicates respiratory dysfunction as a precipitating factor in cases of seizure-induced death. Dysregulation of breathing can occur in epilepsy patients during and after seizures as well as interictally, with many epilepsy patients exhibiting sleep-disordered breathing (SDB), such as obstructive sleep apnea (OSA). The majority of SUDEP cases occur during the night, with the victim found prone in or near a bed. As breathing is modulated in both a time-of-day and sleep state-dependent manner, it is relevant to examine the added burden of nocturnal seizures on respiratory function. This review explores the current state of understanding of the relationship between respiratory function, sleep state and time of day, and epilepsy. We highlight sleep as a particularly vulnerable period for individuals with epilepsy and press that this topic warrants further investigation in order to develop therapeutic interventions to mitigate the risk of SUDEP.
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Affiliation(s)
- Katelyn G. Joyal
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Benjamin L. Kreitlow
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Medical Scientist Training Program, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Gordon F. Buchanan
- Interdisciplinary Graduate Program in Neuroscience, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Department of Neurology, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- Medical Scientist Training Program, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- *Correspondence: Gordon F. Buchanan
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6
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Gu L, Yu Q, Shen Y, Wang Y, Xu Q, Zhang H. The role of monoaminergic neurons in modulating respiration during sleep and the connection with SUDEP. Biomed Pharmacother 2022; 150:112983. [PMID: 35453009 DOI: 10.1016/j.biopha.2022.112983] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/04/2022] [Accepted: 04/14/2022] [Indexed: 11/25/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death among epilepsy patients, occurring even more frequently in cases with anti-epileptic drug resistance. Despite some advancements in characterizing SUDEP, the underlying mechanism remains incompletely understood. This review summarizes the latest advances in our understanding of the pathogenic mechanisms of SUDEP, in order to identify possible targets for the development of new strategies to prevent SUDEP. Based on our previous research along with the current literature, we focus on the role of sleep-disordered breathing (SDB) and its related neural mechanisms to consider the possible roles of monoaminergic neurons in the modulation of respiration during sleep and the occurrence of SUDEP. Overall, this review suggests that targeting the monoaminergic neurons is a promising approach to preventing SUDEP. The proposed roles of SDB and related monoaminergic neural mechanisms in SUDEP provide new insights for explaining the pathogenesis of SUDEP.
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Affiliation(s)
- LeYuan Gu
- Department of Anesthesiology, The Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou 310006, China; Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Qian Yu
- Department of Anesthesiology, The Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou 310006, China; Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Yue Shen
- Department of Anesthesiology, The Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou 310006, China; Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - YuLing Wang
- Department of Anesthesiology, The Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou 310006, China; Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - Qing Xu
- Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China
| | - HongHai Zhang
- Department of Anesthesiology, The Fourth Clinical School of Medicine, Zhejiang Chinese Medical University, Hangzhou 310006, China; Department of Anesthesiology, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Hangzhou, 310006, China; Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou 310006, China.
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7
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Teran FA, Bravo E, Richerson GB. Sudden unexpected death in epilepsy: Respiratory mechanisms. HANDBOOK OF CLINICAL NEUROLOGY 2022; 189:153-176. [PMID: 36031303 PMCID: PMC10191258 DOI: 10.1016/b978-0-323-91532-8.00012-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Epilepsy is one of the most common chronic neurologic diseases, with a prevalence of 1% in the US population. Many people with epilepsy live normal lives, but are at risk of sudden unexpected death in epilepsy (SUDEP). This mysterious comorbidity of epilepsy causes premature death in 17%-50% of those with epilepsy. Most SUDEP occurs after a generalized seizure, and patients are typically found in bed in the prone position. Until recently, it was thought that SUDEP was due to cardiovascular failure, but patients who died while being monitored in hospital epilepsy units revealed that most SUDEP is due to postictal central apnea. Some cases may occur when seizures invade the amygdala and activate projections to the brainstem. Evidence suggests that the pathophysiology is linked to defects in the serotonin system and central CO2 chemoreception, and that there is considerable overlap with mechanisms thought to be involved in sudden infant death syndrome (SIDS). Future work is needed to identify biomarkers for patients at highest risk, improve ascertainment, develop methods to alert caregivers when SUDEP is imminent, and find effective approaches to prevent these fatal events.
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Affiliation(s)
- Frida A Teran
- Department of Neurology, University of Iowa, Iowa City, IA, United States; Medical Scientist Training Program, University of Iowa, Iowa City, IA, United States.
| | - Eduardo Bravo
- Department of Neurology, University of Iowa, Iowa City, IA, United States
| | - George B Richerson
- Department of Neurology, University of Iowa, Iowa City, IA, United States; Department of Molecular Physiology & Biophysics, University of Iowa, Iowa City, IA, United States
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8
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Himmelwright RS, Dominguez JE. Postpartum Respiratory Depression. Anesthesiol Clin 2021; 39:687-709. [PMID: 34776104 DOI: 10.1016/j.anclin.2021.08.003] [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] [Indexed: 11/20/2022]
Abstract
Postpartum respiratory depression is a complex, multifactorial issue that encompasses a patient's baseline preexisting conditions, certain pregnancy-specific conditions or complications, as well as the iatrogenic element of various medications given in the peripartum period. In this review, we discuss many of these factors including obesity, sleep-disordered breathing, chronic lung disease, neuromuscular disorders, opioids, preeclampsia, peripartum cardiomyopathy, postpartum hemorrhage, amniotic fluid embolism, sepsis, acute respiratory distress syndrome (ARDS), and medications such as analgesics, sedatives, anesthetics, and magnesium. Current recommendations for screening, treatment, and prevention are also discussed.
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Affiliation(s)
| | - Jennifer E Dominguez
- Duke University Medical Center, DUMC 3094, MS#9, 2301 Erwin Road, Durham, NC 27710, USA.
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9
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Zhang R, Tan Z, Niu J, Feng HJ. Adrenergic α2 receptors are implicated in seizure-induced respiratory arrest in DBA/1 mice. Life Sci 2021; 284:119912. [PMID: 34461082 PMCID: PMC8484063 DOI: 10.1016/j.lfs.2021.119912] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 07/29/2021] [Accepted: 08/19/2021] [Indexed: 02/03/2023]
Abstract
AIMS Sudden unexpected death in epilepsy (SUDEP) is a serious and underestimated public health burden. Both clinical and animal studies show that seizure-induced respiratory arrest (S-IRA) is the primary cause of death in SUDEP. Our previous studies demonstrated that atomoxetine, a norepinephrine reuptake inhibitor (NRI), suppresses S-IRA in DBA/1 mice, suggesting that noradrenergic neurotransmission modulates S-IRA. However, it remains unclear which adrenoceptors are implicated in S-IRA in DBA/1 mice. MATERIALS AND METHODS Naïve DBA/1 mice exhibit a low incidence of S-IRA, but after primed by acoustic stimulation, they become consistently susceptible to S-IRA. Atomoxetine, adrenoceptor agonists, antagonists or vehicle was intraperitoneally (i.p.) administered alone or in combination, and the effects of drug treatments on S-IRA incidence and seizure behaviors were examined. KEY FINDINGS The incidence of S-IRA in primed DBA/1 mice was significantly reduced by clonidine, an α2 adrenoceptor agonist, as compared with that of the vehicle control. However, compared with the vehicle control, S-IRA was not altered by cirazoline, an α1 agonist. Consistent with previous reports, atomoxetine reduced S-IRA in primed DBA/1 mice. The suppressing effect of atomoxetine on S-IRA was prevented by injection of an α2 adrenoceptor antagonist, yohimbine or atipamezole, but not by prazosin, an α1 antagonist. Administration of α1 or α2 antagonists alone did not promote the incidence of S-IRA in nonprimed DBA/1 mice. SIGNIFICANCE These data demonstrate that noradrenergic neurotransmission modulates S-IRA predominantly via α2 adrenoceptors in DBA/1 mice, indicating that selective activation of α2 adrenoceptors can potentially prevent SUDEP.
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Affiliation(s)
- Rui Zhang
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA; Ningxia Key Laboratory of Cerebrocranial Diseases, Ningxia Medical University, Yinchuan 750004, China
| | - Zheren Tan
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA; Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Jianguo Niu
- Ningxia Key Laboratory of Cerebrocranial Diseases, Ningxia Medical University, Yinchuan 750004, China
| | - Hua-Jun Feng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
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10
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Teneralli RE, Cepeda MS, Kern DM, Novak GP. Individuals who develop drug-resistant epilepsy within a year after initial diagnosis have higher burden of mental and physical diseases one-year prior to epilepsy diagnosis as compared to those whose seizures were controlled during the same interval. Epilepsy Behav 2021; 123:108243. [PMID: 34425326 DOI: 10.1016/j.yebeh.2021.108243] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Revised: 07/22/2021] [Accepted: 07/25/2021] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Epilepsy is a neurological disease characterized by recurrent, unprovoked seizures and its impact on biological, cognitive, psychological, and social outcomes. An unmet need for finding effective treatment options exists. Identifying medical diagnoses present prior to a diagnosis of epilepsy is an important step in increasing our understanding of how people with epilepsy may respond to therapy, help guide clinicians in managing associated comorbid conditions, and inform future research. METHODS A population-based retrospective comparative cohort study was conducted using administrative claims data to explore differences in medical diagnoses prior to an initial diagnosis of epilepsy between patients with and without drug-resistant epilepsy (DRE) identified within one-year post diagnosis by evaluating standardized mean differences between the groups. RESULTS A total of 205,183 patients with newly diagnosed epilepsy were identified. Of those, 4.1% (n = 8340) were considered drug resistant one-year post diagnosis. Pain and mood disorders were the common physical and psychiatric diagnoses in both cohorts. Differences between the newly diagnosed epilepsy and DRE cohorts were observed. Patients in the DRE cohort were younger, had more encounters with the healthcare system, and higher burden of disease for both physical (e.g., headache, neuropathy, muscular-skeletal disorders, and traumatic brain injury) and psychiatric diagnoses (e.g., depression, anxiety, bipolar disorder, suicidal thoughts, drug dependency, and sleep disorders). CONCLUSION Physical and psychiatric diagnoses are common one year prior to first diagnosis of epilepsy in administrative claims data. Compared to patients without DRE, those who develop DRE within one-year post initial diagnosis demonstrated a higher burden of disease.
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Affiliation(s)
- Rachel E Teneralli
- Janssen Research & Development, LLC., Epidemiology, Titusville, NJ, USA.
| | - M Soledad Cepeda
- Janssen Research & Development, LLC., Epidemiology, Titusville, NJ, USA
| | - David M Kern
- Janssen Research & Development, LLC., Epidemiology, Titusville, NJ, USA
| | - Gerald P Novak
- Janssen Research & Development, LLC., Neuroscience, Titusville, NJ, USA
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11
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van der Linde H, Kreir M, Teisman A, Gallacher DJ. Seizure-induced Torsades de pointes:In a canine drug-induced long-QT1 model. J Pharmacol Toxicol Methods 2021; 111:107086. [DOI: 10.1016/j.vascn.2021.107086] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 05/11/2021] [Accepted: 06/08/2021] [Indexed: 12/25/2022]
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12
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Tosh JL, Rhymes ER, Mumford P, Whittaker HT, Pulford LJ, Noy SJ, Cleverley K, Walker MC, Tybulewicz VLJ, Wykes RC, Fisher EMC, Wiseman FK. Genetic dissection of down syndrome-associated alterations in APP/amyloid-β biology using mouse models. Sci Rep 2021; 11:5736. [PMID: 33707583 PMCID: PMC7952899 DOI: 10.1038/s41598-021-85062-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 02/23/2021] [Indexed: 11/26/2022] Open
Abstract
Individuals who have Down syndrome (caused by trisomy of chromosome 21), have a greatly elevated risk of early-onset Alzheimer's disease, in which amyloid-β accumulates in the brain. Amyloid-β is a product of the chromosome 21 gene APP (amyloid precursor protein) and the extra copy or 'dose' of APP is thought to be the cause of this early-onset Alzheimer's disease. However, other chromosome 21 genes likely modulate disease when in three-copies in people with Down syndrome. Here we show that an extra copy of chromosome 21 genes, other than APP, influences APP/Aβ biology. We crossed Down syndrome mouse models with partial trisomies, to an APP transgenic model and found that extra copies of subgroups of chromosome 21 gene(s) modulate amyloid-β aggregation and APP transgene-associated mortality, independently of changing amyloid precursor protein abundance. Thus, genes on chromosome 21, other than APP, likely modulate Alzheimer's disease in people who have Down syndrome.
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Affiliation(s)
- Justin L Tosh
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK
- The Francis Crick Institute, London, NW1 1AT, UK
| | - Elena R Rhymes
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK
| | - Paige Mumford
- The UK Dementia Research Institute, University College London, Queen Square, London, WC1N 3BG, UK
| | - Heather T Whittaker
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK
| | - Laura J Pulford
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK
| | - Sue J Noy
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK
| | - Karen Cleverley
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK
| | | | - Matthew C Walker
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK
| | - Victor L J Tybulewicz
- The Francis Crick Institute, London, NW1 1AT, UK
- Department of Immunology and Inflammation, Imperial College, London, W12 0NN, UK
| | - Rob C Wykes
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK
- Nanomedicine Lab and the Geoffrey Jefferson Brain Research Center, University of Manchester, Manchester, M13 9PT, UK
| | - Elizabeth M C Fisher
- Department of Neuromuscular Diseases, Queen Square Institute of Neurology, University College London, Queen Square, London, WC1N 3BG, UK.
| | - Frances K Wiseman
- The UK Dementia Research Institute, University College London, Queen Square, London, WC1N 3BG, UK.
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13
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Lucchesi M, Silverman JB, Sundaram K, Kollmar R, Stewart M. Proposed Mechanism-Based Risk Stratification and Algorithm to Prevent Sudden Death in Epilepsy. Front Neurol 2021; 11:618859. [PMID: 33569036 PMCID: PMC7868441 DOI: 10.3389/fneur.2020.618859] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 12/30/2020] [Indexed: 12/13/2022] Open
Abstract
Sudden Unexpected Death in Epilepsy (SUDEP) is the leading cause of death in young adults with uncontrolled seizures. First aid guidance to prevent SUDEP, though, has not been previously published because the rarity of monitored cases has made the underlying mechanism difficult to define. This starkly contrasts with the first aid guidelines for sudden cardiac arrest that have been developed based on retrospective studies and expert consensus and the discussion of resuscitation challenges in various American Heart Association certificate courses. However, an increasing amount of evidence from documented SUDEP cases and near misses and from animal models points to a consistent sequence of events that starts with sudden airway occlusion and suggests a mechanistic basis for enhancing seizure first aid. In monitored cases, this sudden airway occlusion associated with seizure activity can be accurately inferred from inductance plethysmography or (depending on recording bandwidth) from electromyographic (EMG) bursts that are associated with inspiratory attempts appearing on the electroencephalogram (EEG) or the electrocardiogram (ECG). In an emergency setting or outside a hospital, seizure first aid can be improved by (1) keeping a lookout for sudden changes in airway status during a seizure, (2) distinguishing thoracic and abdominal movements during attempts to inspire from effective breathing, (3) applying a simple maneuver, the laryngospasm notch maneuver, that may help with airway management when aggressive airway management is unavailable, (4) providing oxygen early as a preventative step to reduce the risk of death, and (5) performing cardiopulmonary resuscitation before the limited post-ictal window of opportunity closes. We propose that these additions to first aid protocols can limit progression of any potential SUDEP case and prevent death. Risk stratification can be improved by recognition of airway occlusion, attendant hypoxia, and need for resuscitation.
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Affiliation(s)
- Michael Lucchesi
- Department of Emergency Medicine, State University of New York Health Sciences University, Brooklyn, NY, United States
| | - Joshua B Silverman
- Department of Otolaryngology, North Shore Long Island Jewish Medical Center, New Hyde Park, NY, United States
| | - Krishnamurthi Sundaram
- Department of Otolaryngology, State University of New York Health Sciences University, Brooklyn, NY, United States
| | - Richard Kollmar
- Department of Otolaryngology, State University of New York Health Sciences University, Brooklyn, NY, United States.,Department of Cell Biology, State University of New York Health Sciences University, Brooklyn, NY, United States
| | - Mark Stewart
- Department of Neurology, State University of New York Health Sciences University, Brooklyn, NY, United States.,Department of Physiology & Pharmacology, State University of New York Health Sciences University, Brooklyn, NY, United States
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14
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Adhikari Y, Jin X. Intraperitoneal injection of lipopolysaccharide prevents seizure-induced respiratory arrest in a DBA/1 mouse model of SUDEP. Epilepsia Open 2020; 5:386-396. [PMID: 32913947 PMCID: PMC7469803 DOI: 10.1002/epi4.12410] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 03/30/2020] [Accepted: 05/03/2020] [Indexed: 12/18/2022] Open
Abstract
OBJECTIVE Sudden unexpected death in epilepsy (SUDEP) is the cause of premature death of 50% patients with chronic refractory epilepsy. Respiratory failure during seizures is regarded as an important mechanism of SUDEP. Previous studies have shown that abnormal serotonergic neurotransmission is involved in the pathogenesis of seizure-induced respiratory failure, while enhancing serotonergic neurotransmission in the brainstem suppresses it. Because peripheral inflammation is known to enhance serotonergic neuron activation and 5-HT synthesis and release, we investigated the effect of intraperitoneal lipopolysaccharide (LPS)-induced inflammation on the S-IRA susceptibility during audiogenic seizures in DBA/1 mice. METHODS After DBA/1 mice were primed by exposing to sound stimulation for three consecutive days, they were tested for seizure severity and seizure-induced respiratory arrest (S-IRA) induced by sound stimulation under different conditions. We determined the dose and time course of the effects of intraperitoneal administration of LPS on audiogenic seizures and S-IRA. The effects of blocking TLR4 or RAGE receptors and blocking 5-HT receptors on the LPS-induced effect on S-IRA were investigated. Statistical significance was evaluated using the Kruskal-Wallis test. RESULTS Intraperitoneal injection of LPS significantly had dose-dependent effects in reducing the incidence of S-IRA as well as seizure severity in DBA/1 mice. The protective effect of LPS on S-IRA peaked at 8-12 hours after LPS injection and was related to both reducing seizure severity and enhancing autoresuscitation. Blocking TLR4 or RAGE receptor with TAK-242 or FPS-ZM1, respectively, prior to LPS injection attenuated its effects on S-IRA and seizure severity. Injection of a nonselective 5-HT receptor antagonist, cyproheptadine, or a 5-HT3 receptor antagonist, ondansetron, was effective in blocking LPS-induced effect on S-IRA. Immunostaining results showed a significant increase in c-Fos-positive serotonergic neurons in the dorsal raphe. SIGNIFICANCE This is the first study that demonstrates the effect of intraperitoneal LPS injection-induced inflammation on reducing S-IRA susceptibility and provides additional evidence supporting the serotonin hypothesis on SUDEP. Our study suggests that inflammation may enhance brainstem 5-HT neurotransmission to promote autoresuscitation during seizure and prevent SUDEP.
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Affiliation(s)
- Yadav Adhikari
- Spinal Cord and Brain Injury Research GroupStark Neurosciences Research Institute. Indiana University School of MedicineIndianapolisIndianaUSA
| | - Xiaoming Jin
- Department of Anatomy, Cell Biology and PhysiologyStark Neurosciences Research InstituteIndiana University School of MedicineIndianapolisIndianaUSA
- Department of Neurological SurgeryStark Neurosciences Research InstituteIndiana University School of MedicineIndianapolisIndianaUSA
- Spinal Cord and Brain Injury Research GroupStark Neurosciences Research Institute. Indiana University School of MedicineIndianapolisIndianaUSA
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15
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Stewart M, Silverman JB, Sundaram K, Kollmar R. Causes and Effects Contributing to Sudden Death in Epilepsy and the Rationale for Prevention and Intervention. Front Neurol 2020; 11:765. [PMID: 32849221 PMCID: PMC7411179 DOI: 10.3389/fneur.2020.00765] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 06/22/2020] [Indexed: 12/15/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) claims the lives of one in every thousand epileptic patients each year. Autonomic, cardiac, and respiratory pieces to a mechanistic puzzle have not yet been completely assembled. We propose a single sequence of causes and effects that unifies disparate and competitive concepts into a single algorithm centered on ictal obstructive apnea. Based on detailed animal studies that are sometimes impossible in humans, and striking parallels with a growing body of clinical examples, this framework (1) accounts for the autonomic, cardiac, and respiratory data to date by showing the causal relationships between specific elements, and (2) highlights specific kinds of data that can be used to precisely classify various patient outcomes. The framework also justifies a “near miss” designation to be applied to any cases with evidence of obstructive apnea even, and perhaps especially, in individuals that do not require resuscitation. Lastly, the rationale for preventative oxygen therapy is demonstrated. With better mechanistic understanding of SUDEP, we suggest changes for detection and classification to increase survival rates and improve risk stratification.
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Affiliation(s)
- Mark Stewart
- Department of Neurology, State University of New York Health Sciences University, Brooklyn, NY, United States.,Department of Physiology & Pharmacology, State University of New York Health Sciences University, Brooklyn, NY, United States
| | - Joshua B Silverman
- Department of Otolaryngology, North Shore Long Island Jewish Medical Center, New Hyde Park, NY, United States
| | - Krishnamurthi Sundaram
- Department of Otolaryngology, State University of New York Health Sciences University, Brooklyn, NY, United States
| | - Richard Kollmar
- Department of Otolaryngology, State University of New York Health Sciences University, Brooklyn, NY, United States.,Department of Cell Biology, State University of New York Health Sciences University, Brooklyn, NY, United States
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16
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Nobis WP, González Otárula KA, Templer JW, Gerard EE, VanHaerents S, Lane G, Zhou G, Rosenow JM, Zelano C, Schuele S. The effect of seizure spread to the amygdala on respiration and onset of ictal central apnea. J Neurosurg 2020; 132:1313-1323. [PMID: 30952127 PMCID: PMC8022327 DOI: 10.3171/2019.1.jns183157] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 01/14/2019] [Indexed: 01/07/2023]
Abstract
OBJECTIVE Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death for patients with refractory epilepsy, and there is increasing evidence for a centrally mediated respiratory depression as a pathophysiological mechanism. The brain regions responsible for a seizure's inducing respiratory depression are unclear-the respiratory nuclei in the brainstem are thought to be involved, but involvement of forebrain structures is not yet understood. The aim of this study was to analyze intracranial EEGs in combination with the results of respiratory monitoring to investigate the relationship between seizure spread to specific mesial temporal brain regions and the onset of respiratory dysfunction and apnea. METHODS The authors reviewed all invasive electroencephalographic studies performed at Northwestern Memorial Hospital (Chicago) since 2010 to identify those cases in which 1) multiple mesial temporal electrodes (amygdala and hippocampal) were placed, 2) seizures were captured, and 3) patients' respiration was monitored. They identified 8 investigations meeting these criteria in patients with temporal lobe epilepsy, and these investigations yielded data on a total of 22 seizures for analysis. RESULTS The onset of ictal apnea associated with each seizure was highly correlated with seizure spread to the amygdala. Onset of apnea occurred 2.7 ± 0.4 (mean ± SEM) seconds after the spread of the seizure to the amygdala, which was significantly earlier than after spread to the hippocampus (10.2 ± 0.7 seconds; p < 0.01). CONCLUSIONS The findings suggest that activation of amygdalar networks is correlated with central apnea during seizures. This study builds on the authors' prior work that demonstrates a role for the amygdala in voluntary respiratory control and suggests a further role in dysfunctional breathing states seen during seizures, with implications for SUDEP pathophysiology.
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Affiliation(s)
- William P. Nobis
- Department of Neurology, Vanderbilt University Medical Center, Nashville, Tennessee
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | | | - Jessica W. Templer
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Elizabeth E. Gerard
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Stephen VanHaerents
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Gregory Lane
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Guangyu Zhou
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Joshua M. Rosenow
- Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Christina Zelano
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Stephan Schuele
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois
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17
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Desai R, Singh S, Patel U, Fong HK, Kaur VP, Varma Y, Madan D, Patel S, Mahuwala Z, Sachdeva R, Kumar G. Frequency of takotsubo cardiomyopathy in epilepsy-related hospitalizations among adults and its impact on in-hospital outcomes: A national standpoint. Int J Cardiol 2020; 299:67-70. [DOI: 10.1016/j.ijcard.2019.07.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 06/24/2019] [Accepted: 07/09/2019] [Indexed: 01/16/2023]
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18
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5-HT neurons and central CO2 chemoreception. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/b978-0-444-64125-0.00021-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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19
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Fukushi I, Takeda K, Uchiyama M, Kurita Y, Pokorski M, Yokota S, Okazaki S, Horiuchi J, Mori Y, Okada Y. Blockade of astrocytic activation delays the occurrence of severe hypoxia-induced seizure and respiratory arrest in mice. J Comp Neurol 2019; 528:1257-1264. [PMID: 31769022 DOI: 10.1002/cne.24828] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/08/2019] [Accepted: 11/08/2019] [Indexed: 01/10/2023]
Abstract
Seizures are induced when subjects are exposed to severe hypoxia. It is followed by ventilatory fall-off and eventual respiratory arrest, which may underlie the pathophysiology of death in patients with epilepsy and severe respiratory disorders. However, the mechanisms of hypoxia-induced seizures have not been fully understood. Because astrocytes are involved in various neurological disorders, we aimed to investigate whether astrocytes are operational in seizure generation and respiratory arrest in a severe hypoxic condition. We examined the effects of astrocytic activation blockade on responses of EEG and ventilation to severe hypoxia. Adult mice were divided into two groups; in one group (n = 24) only vehicle was injected, and in the other group (n = 24) arundic acid, an inhibitory modulator of astrocytic activation, was administered before initiation of recording. After recording EEG and ventilation by whole body plethysmography in room air, the gas in the recording chamber was switched to 5% oxygen (nitrogen balanced) until a seizure and ventilatory depression occurred, followed by prompt switch back to room air. Severe hypoxia initially increased ventilation, followed by a seizure and ventilatory suppression in all mice examined. Fourteen mice without arundic acid showed respiratory arrest during loading of hypoxia. However, 22 mice pretreated with arundic acid did not suffer from respiratory arrest. Time from the onset of hypoxia to the occurrence of seizures was significantly longer in the group with arundic acid than that in the group without arundic acid. We suggest that blockade of astrocytic activation delays the occurrence of seizures and prevents respiratory arrest.
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Affiliation(s)
- Isato Fukushi
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Faculty of Health Sciences, Iryo Sosei University, Iwaki, Japan
| | - Kotaro Takeda
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Faculty of Rehabilitation, School of Healthcare, Fujita Health University, Toyoake, Japan
| | - Makoto Uchiyama
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Department of Synthetic Chemistry and Biological Chemistry Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Yuki Kurita
- Department of Synthetic Chemistry and Biological Chemistry Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Mieczyslaw Pokorski
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Faculty of Physiotherapy, Opole Medical School, Opole, Poland
| | - Shigefumi Yokota
- Department of Anatomy and Neuroscience, Shimane University School of Medicine, Izumo, Japan
| | - Shuntaro Okazaki
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan.,Faculty of Human Sciences, Waseda University, Tokorozawa, Japan
| | - Jouji Horiuchi
- Department of Biomedical Engineering, Graduate School of Science and Engineering, Toyo University, Kawagoe, Japan
| | - Yasuo Mori
- Department of Synthetic Chemistry and Biological Chemistry Graduate School of Engineering, Kyoto University, Kyoto, Japan
| | - Yasumasa Okada
- Clinical Research Center, Murayama Medical Center, Musashimurayama, Japan
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20
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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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21
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Patodia S, Somani A, O'Hare M, Venkateswaran R, Liu J, Michalak Z, Ellis M, Scheffer IE, Diehl B, Sisodiya SM, Thom M. The ventrolateral medulla and medullary raphe in sudden unexpected death in epilepsy. Brain 2019; 141:1719-1733. [PMID: 29608654 PMCID: PMC5972615 DOI: 10.1093/brain/awy078] [Citation(s) in RCA: 72] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Accepted: 02/01/2018] [Indexed: 11/14/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a leading cause of premature death in patients with epilepsy. One hypothesis proposes that sudden death is mediated by post-ictal central respiratory depression, which could relate to underlying pathology in key respiratory nuclei and/or their neuromodulators. Our aim was to investigate neuronal populations in the ventrolateral medulla (which includes the putative human pre-Bötzinger complex) and the medullary raphe. Forty brainstems were studied comprising four groups: 14 SUDEP, six epilepsy controls, seven Dravet syndrome cases and 13 non-epilepsy controls. Serial sections through the medulla (from obex 1 to 10 mm) were stained for Nissl, somatostatin, neurokinin 1 receptor (for pre-Bötzinger complex neurons) and galanin, tryptophan hydroxylase and serotonin transporter (neuromodulatory systems). Using stereology total neuronal number and densities, with respect to obex level, were measured. Whole slide scanning image analysis was used to quantify immunolabelling indices as well as co-localization between markers. Significant findings included reduction in somatostatin neurons and neurokinin 1 receptor labelling in the ventrolateral medulla in sudden death in epilepsy compared to controls (P < 0.05). Galanin and tryptophan hydroxylase labelling was also reduced in sudden death cases and more significantly in the ventrolateral medulla region than the raphe (P < 0.005 and P < 0.05). With serotonin transporter, reduction in labelling in cases of sudden death in epilepsy was noted only in the raphe (P ≤ 0.01); however, co-localization with tryptophan hydroxylase was significantly reduced in the ventrolateral medulla. Epilepsy controls and cases with Dravet syndrome showed less significant alterations with differences from non-epilepsy controls noted only for somatostatin in the ventrolateral medulla (P < 0.05). Variations in labelling with respect to obex level were noted of potential relevance to the rostro-caudal organization of respiratory nuclear groups, including tryptophan hydroxylase, where the greatest statistical difference noted between all epilepsy cases and controls was at obex 9-10 mm (P = 0.034), the putative level of the pre-Bötzinger complex. Furthermore, there was evidence for variation with duration of epilepsy for somatostatin and neurokinin 1 receptor. Our findings suggest alteration to neuronal populations in the medulla in SUDEP with evidence for greater reduction in neuromodulatory neuropeptidergic and mono-aminergic systems, including for galanin, and serotonin. Other nuclei need to be investigated to evaluate if this is part of more widespread brainstem pathology. Our findings could be a result of previous seizures and may represent a pathological risk factor for SUDEP through impaired respiratory homeostasis during a seizure.
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Affiliation(s)
- Smriti Patodia
- Departments of Neuropathology, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Clinical and Experimental Epilepsy and Chalfont Centre for Epilepsy, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Alyma Somani
- Departments of Neuropathology, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Clinical and Experimental Epilepsy and Chalfont Centre for Epilepsy, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Megan O'Hare
- Clinical and Experimental Epilepsy and Chalfont Centre for Epilepsy, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Ranjana Venkateswaran
- Departments of Neuropathology, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Clinical and Experimental Epilepsy and Chalfont Centre for Epilepsy, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Joan Liu
- Departments of Neuropathology, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Clinical and Experimental Epilepsy and Chalfont Centre for Epilepsy, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Department of Biomedical Sciences, University of Westminster London W1W 6UW, UK
| | - Zuzanna Michalak
- Departments of Neuropathology, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Clinical and Experimental Epilepsy and Chalfont Centre for Epilepsy, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Matthew Ellis
- Departments of Neuropathology, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine (Neurology), University of Melbourne, Victoria 3052, Australia
| | - Beate Diehl
- Clinical and Experimental Epilepsy and Chalfont Centre for Epilepsy, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Sanjay M Sisodiya
- Clinical and Experimental Epilepsy and Chalfont Centre for Epilepsy, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK
| | - Maria Thom
- Departments of Neuropathology, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK.,Clinical and Experimental Epilepsy and Chalfont Centre for Epilepsy, UCL, Institute of Neurology, Queen Square, London WC1N 3BG, UK
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DeGiorgio CM, Curtis A, Hertling D, Moseley BD. Sudden unexpected death in epilepsy: Risk factors, biomarkers, and prevention. Acta Neurol Scand 2019; 139:220-230. [PMID: 30443951 DOI: 10.1111/ane.13049] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 11/04/2018] [Accepted: 11/07/2018] [Indexed: 01/01/2023]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is one of the most important direct epilepsy-related causes of death, with an incidence in adults of 1.2 per 1000 person-years. Generalized tonic-clonic seizures have consistently emerged as the leading risk factor for SUDEP, particularly when such seizures are uncontrolled. High seizure burden, lack of antiepileptic drug (AED) treatment, polytherapy, intellectual disability, and prone position at the time of death are other key risk factors. Unfortunately, despite advances in treatment, overall mortality rates in epilepsy are rising. It is imperative that we learn more about SUDEP so that effective prevention strategies can be implemented. To help identify persons at greater risk of SUDEP and in need of closer monitoring, biomarkers are needed. Candidate biomarkers include electrocardiographic, electroencephalographic, and imaging abnormalities observed more frequently in those who have died suddenly and unexpectedly. As our knowledge of the pathophysiologic mechanisms behind SUDEP has increased, various preventative measures have been proposed. These include lattice pillows, postictal oxygen therapy, selective serotonin reuptake inhibitors, and inhibitors of opiate and adenosine receptors. Unfortunately, no randomized clinical trials are available to definitively conclude these measures are effective. Rather, gaining the best control of seizures possible (with AEDs, devices, and resective surgery) still remains the intervention with the best evidence to reduce the risk of SUDEP. In this evidence-based review, we explore the incidence of SUDEP and review the risk factors, biomarkers, and latest prevention strategies.
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Affiliation(s)
| | - Ashley Curtis
- Undergraduate Interdepartmental Program for Neuroscience, UCLA Los Angeles California
| | - Dieter Hertling
- Undergraduate Interdepartmental Program for Neuroscience, UCLA Los Angeles California
| | - Brian D. Moseley
- Department of Neurology and Rehabilitation Medicine University of Cincinnati Cincinnati Ohio
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Budde RB, Arafat MA, Pederson DJ, Lovick TA, Jefferys JGR, Irazoqui PP. Acid reflux induced laryngospasm as a potential mechanism of sudden death in epilepsy. Epilepsy Res 2018; 148:23-31. [PMID: 30336367 PMCID: PMC6276113 DOI: 10.1016/j.eplepsyres.2018.10.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/22/2018] [Accepted: 10/07/2018] [Indexed: 12/16/2022]
Abstract
OBJECTIVE Recent research suggests that obstructive laryngospasm and consequent respiratory arrest may be a mechanism in sudden unexpected death in epilepsy. We sought to test a new hypothesis that this laryngospasm is caused by seizures driving reflux of stomach acid into the larynx, rather than spontaneous pathological activity in the recurrent laryngeal nerve. APPROACH We used an acute kainic acid model under urethane anesthesia to observe seizure activity in Long-Evans rats. We measured the pH in the esophagus and respiratory activity. In a subset of experiments, we blocked acid movement up the esophagus with a balloon catheter. MAIN RESULTS In all cases of sudden death, terminal apnea was preceded by a large pH drop from 7 to 2 in the esophagus. In several animals we observed acidic fluid exiting the mouth, sometimes in large quantities. In animals where acid movement was blocked, sudden deaths did not occur. No acid was detected in controls. SIGNIFICANCE The results suggest that acid movement up the esophagus is a trigger for sudden death in KA induced seizures. The fact that blocking acid also eliminates sudden death implies causation. These results may provide insight to the mechanism of SUDEP in humans.
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Affiliation(s)
- Ryan B Budde
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, US
| | - Muhammad A Arafat
- Department of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, US
| | - Daniel J Pederson
- Department of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, US
| | - Thelma A Lovick
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, US; School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, UK
| | - John G R Jefferys
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, US; Department of Pharmacology, Oxford University, Oxford, UK; Department of Biochemistry, Oxford University, Oxford, UK
| | - Pedro P Irazoqui
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, US; Department of Electrical and Computer Engineering, Purdue University, West Lafayette, IN, US.
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Stewart M. An explanation for sudden death in epilepsy (SUDEP). J Physiol Sci 2018; 68:307-320. [PMID: 29542031 PMCID: PMC10717429 DOI: 10.1007/s12576-018-0602-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/06/2018] [Indexed: 01/02/2023]
Abstract
This review traces the examination of autonomic, cardiovascular, and respiratory derangements associated with seizure activity in the clinical and preclinical literature generally, and in the author's animal model specifically, and concludes with the author's views on the potential mechanisms for sudden death in epilepsy (SUDEP). An animal model that employs kainic acid-induced seizures on a background of urethane anesthesia has permitted unprecedented access to the behavior of autonomic, cardiovascular, and respiratory systems during seizure activity. The result is a detailed description of the major causes of death and how this animal model can be used to develop and test preventative and interventional strategies. A critical translational step was taken when the rat data were shown to directly parallel data from definite SUDEP cases in the clinical literature. The reasons why ventricular fibrillation as a cause of death is so rarely reported and tools for verifying that seizure-associated laryngospasm can induce obstructive apnea as a cause of death are discussed in detail. Many details of the specific kinetics of activation of brainstem neurons serving autonomic and respiratory function remain to be elucidated, but the boundary conditions described in this review provide an excellent framework for more focused studies. A number of studies conducted in animal models of seizure activity and in epilepsy patients have contributed information on the autonomic, cardiovascular, and respiratory consequences of seizure activity spreading through hypothalamus and brainstem to the periphery. The result is detailed information on the systemic impact of seizure spread and the development of an understanding of the essential mechanistic features of sudden unexpected death in epilepsy (SUDEP). This review summarizes translation of data obtained from animal models to biomarkers that are useful in evaluating data from epilepsy patients.
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Affiliation(s)
- Mark Stewart
- Department of Physiology and Pharmacology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY, 11203, USA.
- Department of Neurology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY, 11203, USA.
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Gauvin DV, Zimmermann ZJ, Yoder J, Harter M, Holdsworth D, Kilgus Q, May J, Dalton J, Baird TJ. A predictive index of biomarkers for ictogenesis from tier I safety pharmacology testing that may warrant tier II EEG studies. J Pharmacol Toxicol Methods 2018; 94:50-63. [PMID: 29751085 DOI: 10.1016/j.vascn.2018.05.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/25/2018] [Accepted: 05/03/2018] [Indexed: 12/20/2022]
Abstract
Three significant contributions to the field of safety pharmacology were recently published detailing the use of electroencephalography (EEG) by telemetry in a critical role in the successful evaluation of a compound during drug development (1] Authier, Delatte, Kallman, Stevens & Markgraf; JPTM 2016; 81:274-285; 2] Accardi, Pugsley, Forster, Troncy, Huang & Authier; JPTM; 81: 47-59; 3] Bassett, Troncy, Pouliot, Paquette, Ascaha, & Authier; JPTM 2016; 70: 230-240). These authors present a convincing case for monitoring neocortical biopotential waveforms (EEG, ECoG, etc) during preclinical toxicology studies as an opportunity for early identification of a central nervous system (CNS) risk during Investigational New Drug (IND) Enabling Studies. This review is about "ictogenesis" not "epileptogenesis". It is intended to characterize overt behavioral and physiological changes suggestive of drug-induced neurotoxicity/ictogenesis in experimental animals during Tier 1 safety pharmacology testing, prior to first dose administration in man. It is the presence of these predictive or comorbid biomarkers expressed during the requisite conduct of daily clinical or cage side observations, and in early ICH S7A Tier I CNS, pulmonary and cardiovascular safety study designs that should initiate an early conversation regarding Tier II inclusion of EEG monitoring. We conclude that there is no single definitive clinical marker for seizure liability but plasma exposures might add to set proper safety margins when clinical convulsions are observed. Even the observation of a study-related full tonic-clonic convulsion does not establish solid ground to require the financial and temporal investment of a full EEG study under the current regulatory standards. PREFATORY NOTE For purposes of this review, we have adopted the FDA term "sponsor" as it refers to any person who takes the responsibility for and initiates a nonclinical investigations of new molecular entities; FDA uses the term "sponsor" primarily in relation to investigational new drug application submissions.
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Affiliation(s)
- David V Gauvin
- Neurobehavioral Science and MPI Research (A Charles Rivers Company), Mattawan, MI, United States.
| | - Zachary J Zimmermann
- Neurobehavioral Science and MPI Research (A Charles Rivers Company), Mattawan, MI, United States
| | - Joshua Yoder
- Neurobehavioral Science and MPI Research (A Charles Rivers Company), Mattawan, MI, United States
| | - Marci Harter
- Safety Pharmacology, MPI Research (A Charles Rivers Company), Mattawan, MI, United States
| | - David Holdsworth
- Safety Pharmacology, MPI Research (A Charles Rivers Company), Mattawan, MI, United States
| | - Quinn Kilgus
- Safety Pharmacology, MPI Research (A Charles Rivers Company), Mattawan, MI, United States
| | - Jonelle May
- Safety Pharmacology, MPI Research (A Charles Rivers Company), Mattawan, MI, United States
| | - Jill Dalton
- Safety Pharmacology, MPI Research (A Charles Rivers Company), Mattawan, MI, United States
| | - Theodore J Baird
- Drug Safety Assessment, MPI Research (A Charles Rivers Company), Mattawan, MI, United States
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Zhang H, Zhao H, Zeng C, Van Dort C, Faingold CL, Taylor NE, Solt K, Feng HJ. Optogenetic activation of 5-HT neurons in the dorsal raphe suppresses seizure-induced respiratory arrest and produces anticonvulsant effect in the DBA/1 mouse SUDEP model. Neurobiol Dis 2018; 110:47-58. [PMID: 29141182 PMCID: PMC5748009 DOI: 10.1016/j.nbd.2017.11.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 10/29/2017] [Accepted: 11/11/2017] [Indexed: 01/02/2023] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a devastating epilepsy complication. Seizure-induced respiratory arrest (S-IRA) occurs in many witnessed SUDEP patients and animal models as an initiating event leading to death. Thus, understanding the mechanisms underlying S-IRA will advance the development of preventive strategies against SUDEP. Serotonin (5-HT) is an important modulator for many vital functions, including respiration and arousal, and a deficiency of 5-HT signaling is strongly implicated in S-IRA in animal models, including the DBA/1 mouse. However, the brain structures that contribute to S-IRA remain elusive. We hypothesized that the dorsal raphe (DR), which sends 5-HT projections to the forebrain, is implicated in S-IRA. The present study used optogenetics in the DBA/1 mouse model of SUDEP to selectively activate 5-HT neurons in the DR. Photostimulation of DR 5-HT neurons significantly and reversibly reduced the incidence of S-IRA evoked by acoustic stimulation. Activation of 5-HT neurons in the DR suppressed tonic seizures in most DBA/1 mice without altering the seizure latency and duration of wild running and clonic seizures evoked by acoustic stimulation. This suppressant effect of photostimulation on S-IRA is independent of seizure models, as optogenetic stimulation of DR also reduced S-IRA induced by pentylenetetrazole, a proconvulsant widely used to model human generalized seizures. The S-IRA-suppressing effect of photostimulation was increased by 5-hydroxytryptophan, a chemical precursor for 5-HT synthesis, and was reversed by ondansetron, a specific 5-HT3 receptor antagonist, indicating that reduction of S-IRA by photostimulation of the DR is specifically mediated by enhanced 5-HT neurotransmission. Our findings suggest that deficits in 5-HT neurotransmission in the DR are implicated in S-IRA in DBA/1 mice, and that targeted intervention in the DR is potentially useful for prevention of SUDEP.
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Affiliation(s)
- Honghai Zhang
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Department of Anesthesia, Harvard Medical School, Boston, MA 02114, USA; Department of Anesthesia, Hangzhou First People's Hospital, Nanjing Medical University, Hangzhou 310006, China
| | - Haiting Zhao
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Department of Anesthesia, Harvard Medical School, Boston, MA 02114, USA; Department of Neurology, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Chang Zeng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Department of Anesthesia, Harvard Medical School, Boston, MA 02114, USA; Health Management Center, Xiangya Hospital, Central South University, Changsha 410008, China
| | - Christa Van Dort
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Department of Anesthesia, Harvard Medical School, Boston, MA 02114, USA; Department of Brain and Cognitive Sciences, MIT, Cambridge, MA 02139, USA; Picower Institute for Learning and Memory, MIT, Cambridge, MA 02139, USA
| | - Carl L Faingold
- Department of Pharmacology and Neurology, Division of Neurosurgery, Southern Illinois University School of Medicine, Springfield, IL 62794, USA
| | - Norman E Taylor
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Department of Anesthesia, Harvard Medical School, Boston, MA 02114, USA
| | - Ken Solt
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Department of Anesthesia, Harvard Medical School, Boston, MA 02114, USA
| | - Hua-Jun Feng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Department of Anesthesia, Harvard Medical School, Boston, MA 02114, USA.
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Cozzolino O, Marchese M, Trovato F, Pracucci E, Ratto GM, Buzzi MG, Sicca F, Santorelli FM. Understanding Spreading Depression from Headache to Sudden Unexpected Death. Front Neurol 2018; 9:19. [PMID: 29449828 PMCID: PMC5799941 DOI: 10.3389/fneur.2018.00019] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Accepted: 01/11/2018] [Indexed: 01/03/2023] Open
Abstract
Spreading depression (SD) is a neurophysiological phenomenon characterized by abrupt changes in intracellular ion gradients and sustained depolarization of neurons. It leads to loss of electrical activity, changes in the synaptic architecture, and an altered vascular response. Although SD is often described as a unique phenomenon with homogeneous characteristics, it may be strongly affected by the particular triggering event and by genetic background. Furthermore, SD may contribute differently to the pathogenesis of widely heterogeneous clinical conditions. Indeed, clinical disorders related to SD vary in their presentation and severity, ranging from benign headache conditions (migraine syndromes) to severely disabling events, such as cerebral ischemia, or even death in people with epilepsy. Although the characteristics and mechanisms of SD have been dissected using a variety of approaches, ranging from cells to human models, this phenomenon remains only partially understood because of its complexity and the difficulty of obtaining direct experimental data. Currently, clinical monitoring of SD is limited to patients who require neurosurgical interventions and the placement of subdural electrode strips. Significantly, SD events recorded in humans display electrophysiological features that are essentially the same as those observed in animal models. Further research using existing and new experimental models of SD may allow a better understanding of its core mechanisms, and of their differences in different clinical conditions, fostering opportunities to identify and develop targeted therapies for SD-related disorders and their worst consequences.
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Affiliation(s)
- Olga Cozzolino
- NEST, Istituto Nanoscienze CNR and Scuola Normale Superiore, Pisa, Italy
| | - Maria Marchese
- Molecular Medicine and Clinical Neurophysiology Laboratories, Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Francesco Trovato
- NEST, Istituto Nanoscienze CNR and Scuola Normale Superiore, Pisa, Italy
| | - Enrico Pracucci
- NEST, Istituto Nanoscienze CNR and Scuola Normale Superiore, Pisa, Italy
| | - Gian Michele Ratto
- NEST, Istituto Nanoscienze CNR and Scuola Normale Superiore, Pisa, Italy
| | | | - Federico Sicca
- Molecular Medicine and Clinical Neurophysiology Laboratories, Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Pisa, Italy
| | - Filippo M Santorelli
- Molecular Medicine and Clinical Neurophysiology Laboratories, Department of Developmental Neuroscience, IRCCS Fondazione Stella Maris, Pisa, Italy
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Dorsal Raphe Serotonin Neurons Mediate CO 2-Induced Arousal from Sleep. J Neurosci 2018; 38:1915-1925. [PMID: 29378860 DOI: 10.1523/jneurosci.2182-17.2018] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 01/07/2018] [Accepted: 01/10/2018] [Indexed: 01/10/2023] Open
Abstract
Arousal from sleep in response to CO2 is a critical protective phenomenon. Dysregulation of CO2-induced arousal contributes to morbidity and mortality from prevalent diseases, such as obstructive sleep apnea and sudden infant death syndrome. Despite the critical nature of this protective reflex, the precise mechanism for CO2-induced arousal is unknown. Because CO2 is a major regulator of breathing, prevailing theories suggest that activation of respiratory chemo- and mechano-sensors is required for CO2-induced arousal. However, populations of neurons that are not involved in the regulation of breathing are also chemosensitive. Among these are serotonin (5-HT) neurons in the dorsal raphe nucleus (DRN) that comprise a component of the ascending arousal system. We hypothesized that direct stimulation of these neurons with CO2 could cause arousal from sleep independently of enhancing breathing. Dialysis of CO2-rich acidified solution into DRN, but not medullary raphe responsible for modulating breathing, caused arousal from sleep. Arousal was lost in mice with a genetic absence of 5-HT neurons, and with acute pharmacological or optogenetic inactivation of DRN 5-HT neurons. Here we demonstrate that CO2 can cause arousal from sleep directly, without requiring enhancement of breathing, and that chemosensitive 5-HT neurons in the DRN critically mediate this arousal. Better understanding mechanisms underlying this protective reflex may lead to interventions to reduce disease-associated morbidity and mortality.SIGNIFICANCE STATEMENT Although CO2-induced arousal is critical to a number of diseases, the specific mechanism is not well understood. We previously demonstrated that serotonin (5-HT) neurons are important for CO2-induced arousal, as mice without 5-HT neurons do not arouse to CO2 Many have interpreted this to mean that medullary 5-HT neurons that regulate breathing are important in this arousal mechanism. Here we found that direct application of CO2-rich aCSF to the dorsal raphe nucleus, but not the medullary raphe, causes arousal from sleep, and that this arousal was lost with genetic ablation or acute inhibition of 5-HT neurons. We propose that 5-HT neurons in the dorsal raphe nucleus can be activated directly by CO2 to cause arousal independently of respiratory activation.
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Feng HJ, Faingold CL. Abnormalities of serotonergic neurotransmission in animal models of SUDEP. Epilepsy Behav 2017; 71:174-180. [PMID: 26272185 PMCID: PMC4749463 DOI: 10.1016/j.yebeh.2015.06.008] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 06/05/2015] [Accepted: 06/06/2015] [Indexed: 12/25/2022]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a devastating event, and both DBA/1 and DBA/2 mice have been shown to be relevant animal models for studying SUDEP. DBA mice exhibit seizure-induced respiratory arrest (S-IRA), leading to cardiac arrest and subsequent sudden death after generalized audiogenic seizures (AGSs). This sequence of terminal events is also observed in the majority of witnessed human SUDEP cases. Several pathophysiological mechanisms, including respiratory/cardiac dysfunction, have been proposed to contribute to human SUDEP. Several (but not all) selective serotonin (5-HT) reuptake inhibitors (SSRIs), including fluoxetine, can reversibly block S-IRA, and abnormal expression of 5-HT receptors is found in the brainstem of DBA mice. DBA mice, which do not initially show S-IRA, exhibit S-IRA after treatment with a nonselective 5-HT antagonist. These studies suggest that abnormalities of 5-HT neurotransmission are involved in the pathogenesis of S-IRA in DBA mice. Serotonergic (5-HT) transmission plays an important role in normal respiration, and DBA mice exhibiting S-IRA can be resuscitated using a rodent ventilator. It is important and interesting to know if fluoxetine blocks S-IRA in DBA mice by enhancing respiratory ventilation. To test this, the effects of breathing stimulants, doxapram, and 5,6,7,8-tetrahydropyrido[4,3-d]pyrimidine (PK-THPP) were compared with the effects of fluoxetine on S-IRA in DBA/1 mice. Although fluoxetine reduces the incidence of S-IRA in DBA/1 mice, as reported previously, the same dose of fluoxetine fails to enhance baseline respiratory ventilation in the absence of AGSs. Doxapram and PK-THPP augment the baseline ventilation in DBA/1 mice. However, these breathing stimulants are ineffective in preventing S-IRA in DBA/1 mice. These data suggest that fluoxetine blocks S-IRA in DBA/1 mice by cellular/molecular mechanisms other than enhancement of basal ventilation. Future research directions are also discussed. This article is part of a Special Issue entitled "Genetic and Reflex Epilepsies, Audiogenic Seizures and Strains: From Experimental Models to the Clinic".
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Affiliation(s)
- Hua-Jun Feng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA 02114, USA.
| | - Carl L. Faingold
- Department of Pharmacology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, Illinois 62794, U.S.A
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Postictal apnea as an important mechanism for SUDEP: A near-SUDEP with continuous EEG-ECG-EMG recording. J Clin Neurosci 2017; 43:130-132. [PMID: 28576433 DOI: 10.1016/j.jocn.2017.04.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 04/22/2017] [Indexed: 11/22/2022]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is one of the most frequent causes of death among patients with epilepsy. Most SUDEP or near-SUDEP are unwitnessed and not observed or recorded during video-EEG recording in epilepsy monitoring units. This report describes a young woman with post ictal apnea and generalized EEG suppression (PGES) after a secondary generalized tonic-clonic seizure (sGTCS). This was accompanied by bradycardia and then ventricular tachycardia (VT). But at the end of VT, the patient's breath recovered without any intervention, such as cardio-respiratory resuscitation. This case report with continuous EEG, EKG, EMG during near SUDEP may provide insights into the mechanism of action.
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Kommajosyula SP, Randall ME, Brozoski TJ, Odintsov BM, Faingold CL. Specific subcortical structures are activated during seizure-induced death in a model of sudden unexpected death in epilepsy (SUDEP): A manganese-enhanced magnetic resonance imaging study. Epilepsy Res 2017. [PMID: 28646692 DOI: 10.1016/j.eplepsyres.2017.05.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Sudden unexpected death in epilepsy (SUDEP) is a major concern for patients with epilepsy. In most witnessed cases of SUDEP generalized seizures and respiratory failure preceded death, and pre-mortem neuroimaging studies in SUDEP patients observed changes in specific subcortical structures. Our study examined the role of subcortical structures in the DBA/1 mouse model of SUDEP using manganese-enhanced magnetic resonance imaging (MEMRI). These mice exhibit acoustically-evoked generalized seizures leading to seizure-induced respiratory arrest (S-IRA) that results in sudden death unless resuscitation is rapidly instituted. MEMRI data in the DBA/1 mouse brain immediately after acoustically-induced S-IRA were compared to data in C57 (control) mice that were exposed to the same acoustic stimulus that did not trigger seizures. The animals were anesthetized and decapitated immediately after seizure in DBA/1 mice and after an equivalent time in control mice. Comparative T1 weighted MEMRI images were evaluated using a 14T MRI scanner and quantified. We observed significant increases in activity in DBA/1 mice as compared to controls at previously-implicated auditory (superior olivary complex) and sensorimotor-limbic [periaqueductal gray (PAG) and amygdala] networks and also in structures in the respiratory network. The activity at certain raphe nuclei was also increased, suggesting activation of serotonergic mechanisms. These data are consistent with previous findings that enhancing the action of serotonin prevents S-IRA in this SUDEP model. Increased activity in the PAG and the respiratory and raphe nuclei suggest that compensatory mechanisms for apnea may have been activated by S-IRA, but they were not sufficient to prevent death. The present findings indicate that changes induced by S-IRA in specific subcortical structures in DBA/1 mice are consistent with human SUDEP findings. Understanding the changes in brain activity during seizure-induced death in animals may lead to improved approaches directed at prevention of human SUDEP.
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Affiliation(s)
- Srinivasa P Kommajosyula
- Department of Pharmacology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, IL 62794-9629, United States
| | - Marcus E Randall
- Department of Pharmacology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, IL 62794-9629, United States
| | - Thomas J Brozoski
- Department of Surgery/Otolaryngology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, IL 62794-9629, United States
| | - Boris M Odintsov
- Beckman Institute, University of Illinois Urbana-Champaign, 405 N. Mathews Ave., Urbana, IL, United States
| | - Carl L Faingold
- Department of Pharmacology, Southern Illinois University School of Medicine, P.O. Box 19629, Springfield, IL 62794-9629, United States.
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33
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Li J, Ming Q, Lin W. The insula lobe and sudden unexpected death in epilepsy: a hypothesis. Epileptic Disord 2017; 19:10-14. [DOI: 10.1684/epd.2017.0890] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/28/2023]
Affiliation(s)
- Jia Li
- Department of Neurology and Neuroscience Center First Hospital of Jilin University China
| | - Qianwen Ming
- Department of Neurology and Neuroscience Center First Hospital of Jilin University China
| | - Weihong Lin
- Department of Neurology and Neuroscience Center First Hospital of Jilin University China
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Villiere SM, Nakase K, Kollmar R, Silverman J, Sundaram K, Stewart M. Seizure-associated central apnea in a rat model: Evidence for resetting the respiratory rhythm and activation of the diving reflex. Neurobiol Dis 2017; 101:8-15. [PMID: 28153424 DOI: 10.1016/j.nbd.2017.01.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 01/02/2017] [Accepted: 01/25/2017] [Indexed: 12/18/2022] Open
Abstract
Respiratory derangements, including irregular, tachypnic breathing and central or obstructive apnea can be consequences of seizure activity in epilepsy patients and animal models. Periods of seizure-associated central apnea, defined as periods >1s with rapid onset and offset of no airflow during plethysmography, suggest that seizures spread to brainstem respiratory regions to disrupt breathing. We sought to characterize seizure-associated central apneic episodes as an indicator of seizure impact on the respiratory rhythm in rats anesthetized with urethane and given parenteral kainic acid to induce recurring seizures. We measured central apneic period onsets and offsets to determine if onset-offset relations were a consequence of 1) a reset of the respiratory rhythm, 2) a transient pausing of the respiratory rhythm, resuming from the pause point at the end of the apneic period, 3) a transient suppression of respiratory behavior with apnea offset predicted by a continuation of the breathing pattern preceding apnea, or 4) a random re-entry into the respiratory cycle. Animals were monitored with continuous ECG, EEG, and plethysmography. One hundred ninety central apnea episodes (1.04 to 36.18s, mean: 3.2±3.7s) were recorded during seizure activity from 7 rats with multiple apneic episodes. The majority of apneic period onsets occurred during expiration (125/161 apneic episodes, 78%). In either expiration or inspiration, apneic onsets tended to occur late in the cycle, i.e. between the time of the peak and end of expiration (82/125, 66%) or inspiration (34/36, 94%). Apneic period offsets were more uniformly distributed between early and late expiration (27%, 34%) and inspiration (16%, 23%). Differences between the respiratory phase at the onset of apnea and the corresponding offset phase varied widely, even within individual animals. Each central apneic episode was associated with a high frequency event in EEG or ECG records at onset. High frequency events that were not associated with flatline plethysmographs revealed a constant plethysmograph pattern within each animal, suggesting a clear reset of the respiratory rhythm. The respiratory rhythm became highly variable after about 1s, however, accounting for the unpredictability of the offset phase. The dissociation of respiratory rhythm reset from the cessation of airflow also suggested that central apneic periods involved activation of brainstem regions serving the diving reflex to eliminate the expression of respiratory movements. This conclusion was supported by the decreased heart rate as a function of apnea duration. We conclude that seizure-associated central apnea episodes are associated with 1) a reset of the respiratory rhythm, and 2) activation of brainstem regions serving the diving reflex to suppress respiratory behavior. The significance of these conclusions is that these details of seizure impact on brainstem circuitry represent metrics for assessing seizure spread and potentially subclassifying seizure patterns.
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Affiliation(s)
- S M Villiere
- Department of Physiology & Pharmacology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States; Research Initiative for Scientific Enhancement (RISE) Program, City University of New York Medgar Evers College, 1638 Bedford Avenue, Brooklyn, NY 11225, United States
| | - K Nakase
- Department of Physiology & Pharmacology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States
| | - R Kollmar
- Department of Cell Biology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States; Department of Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States
| | - J Silverman
- Department of Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States
| | - K Sundaram
- Department of Otolaryngology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States
| | - M Stewart
- Department of Physiology & Pharmacology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States; Department of Neurology, State University of New York Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, NY 11203, United States.
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35
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Liu F, Wang X. Diagnosis and treatment of epilepsy and sleep apnea comorbidity. Expert Rev Neurother 2016; 17:475-485. [PMID: 27866428 DOI: 10.1080/14737175.2017.1262259] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Feng Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
| | - Xuefeng Wang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, Chongqing, China
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Faingold CL, Randall M, Zeng C, Peng S, Long X, Feng HJ. Serotonergic agents act on 5-HT 3 receptors in the brain to block seizure-induced respiratory arrest in the DBA/1 mouse model of SUDEP. Epilepsy Behav 2016; 64:166-170. [PMID: 27743549 PMCID: PMC5123739 DOI: 10.1016/j.yebeh.2016.09.034] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Revised: 09/13/2016] [Accepted: 09/16/2016] [Indexed: 11/18/2022]
Abstract
Drugs that enhance the action of serotonin (5-hydroxytrypamine, 5-HT), including several selective serotonin reuptake inhibitors (SSRIs), reduce susceptibility to seizure-induced respiratory arrest (S-IRA) that leads to death in the DBA/1 mouse model of sudden unexpected death in epilepsy (SUDEP). However, it is not clear if specific 5-HT receptors are important in the action of these drugs and whether the brain is the major site of action of these agents in this SUDEP model. The current study examined the actions of agents that affect the 5-HT3 receptor subtype on S-IRA and whether intracerebroventricular (ICV) microinjection of an SSRI would reduce S-IRA susceptibility in DBA/1 mice. The data indicate that systemic administration of SR 57227, a 5-HT3 agonist, was effective in blocking S-IRA in doses that did not block seizures, and the S-IRA blocking effect of the SSRI, fluoxetine, was abolished by coadministration of a 5-HT3 antagonist, ondansetron. Intracerebroventricular administration of fluoxetine in the present study was also able to block S-IRA without blocking seizures. These findings suggest that 5-HT3 receptors play an important role in the block of S-IRA by serotonergic agents, such as SSRIs, which is consistent with the abnormal expression of 5-HT3 receptors in the brainstem of DBA mice observed previously. Taken together, these data indicate that systemically administered serotonergic agents act, at least, in part, in the brain, to reduce S-IRA susceptibility in DBA/1 mice and that 5-HT3 receptors may be important to this effect.
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Affiliation(s)
- Carl L Faingold
- Department of Pharmacology and Neurology, Southern Illinois University, School of Medicine, Springfield, IL, USA.
| | - Marcus Randall
- Department of Pharmacology and Neurology, Southern Illinois University, School of Medicine, Springfield, IL, USA
| | - Chang Zeng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Health Management Center, Xiangya Hospital, Central South University, Changsha, China
| | - Shifang Peng
- Health Management Center, Xiangya Hospital, Central South University, Changsha, China
| | - Xiaoyan Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Hua-Jun Feng
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
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Abstract
Authors: Kevin D Graber, MD, Jeffrey Buchhalter, MD, PhD, Elson So, MD, Rainer Surges, MD, Detlev Boison, PhD, Franck Kalume, PhD, Cyndi Wright, Brian Gehlbach, MD, Jeff Noebels, MD, PhD, Vicky Whittemore, PhD, Elizabeth J. Donner, MD, MSc, Tom Stanton, MPP, Henry Smithson, MD, Jane Hanna, Masud Seyal, MD, PhD, Philippe Ryvlin, MD, PhD The third biannual Partners Against Mortality in Epilepsy (PAME) conference was held in Alexandria, VA from June 23-26, 2016. This was an intimate meeting of clinical and basic scientists, clinicians, people affected by Sudden Unexpected Death in Epilepsy Patients (SUDEP) in a loved one, people living with epilepsy and patient advocate organizations. Plenary sessions have been summarized by moderators, including: 1) Mortality in people with epilepsy: epidemiology and surveillance. 2) Mortality in children. 3) What do we know about the factors that predispose certain people to die from a seizure? 4) What are the events that occur during and after a seizure that cause a death in SUDEP? 5) What are the options for prevention now and in the future? 6) Advocacy perspectives: how can we speed up awareness and prevention? 7) Updates and discussion on select programs in mortality research. Breakout sessions allowed for a more focused audience. Those summarized here are: Frequent non-SUDEP causes of mortality in people with epilepsy; Mechanisms of SUDEP; Lessons learned in grief and how to better support families; Future directions for research to impact prevention; and How do we improve SUDEP risk disclosure? While significant progress has been made with review of human mortality in epilepsy and study of animal models, this meeting emphasized the need for: better understandings of the epidemiology of SUDEP, advances in the understandings of mechanisms, continued search for biomarkers and preventative measures, patient education, increased awareness, continued advocacy for patient and family support and research funding.
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Nakase K, Kollmar R, Lazar J, Arjomandi H, Sundaram K, Silverman J, Orman R, Weedon J, Stefanov D, Savoca E, Tordjman L, Stiles K, Ihsan M, Nunez A, Guzman L, Stewart M. Laryngospasm, central and obstructive apnea during seizures: Defining pathophysiology for sudden death in a rat model. Epilepsy Res 2016; 128:126-139. [PMID: 27835782 DOI: 10.1016/j.eplepsyres.2016.08.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 06/27/2016] [Accepted: 08/07/2016] [Indexed: 12/21/2022]
Abstract
Seizure spread into the autonomic nervous system can result in life-threatening cardiovascular and respiratory dysfunction. Here we report on a less-studied consequence of such autonomic derangements-the possibility of laryngospasm and upper-airway occlusion. We used parenteral kainic acid to induce recurring seizures in urethane-anesthetized Sprague Dawley rats. EEG recordings and combinations of cardiopulmonary monitoring, including video laryngoscopy, were performed during multi-unit recordings of recurrent laryngeal nerve (RLN) activity or head-out plethysmography with or without endotracheal intubation. Controlled occlusions of a tracheal tube were used to study the kinetics of cardiac and respiratory changes after sudden obstruction. Seizure activity caused significant firing increases in the RLN that were associated with abnormal, high-frequency movements of the vocal folds. Partial airway obstruction from laryngospasm was evident in plethysmograms and was prevented by intubation. Complete glottic closure (confirmed by laryngoscopy) occurred in a subset of non-intubated animals in association with the largest increases in RLN activity, and cessation of airflow was followed in all obstructed animals within tens of seconds by ST-segment elevation, bradycardia, and death. Periods of central apnea occurred in both intubated and non-intubated rats during seizures for periods up to 33s and were associated with modestly increased RLN activity, minimal cardiac derangements, and an open airway on laryngoscopy. In controlled complete airway occlusions, respiratory effort to inspire progressively increased, then ceased, usually in less than 1min. Respiratory arrest was associated with left ventricular dilatation and eventual asystole, an elevation of systemic blood pressure, and complete glottic closure. Severe laryngospasm contributed to the seizure- and hypoxemia-induced conditions that resulted in sudden death in our rat model, and we suggest that this mechanism could contribute to sudden death in epilepsy.
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Affiliation(s)
- K Nakase
- Department of Physiology & Pharmacology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - R Kollmar
- Department of Cell Biology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States; Department of Otolaryngology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - J Lazar
- Department of Medicine (Division of Cardiology), State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - H Arjomandi
- Department of Otolaryngology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - K Sundaram
- Department of Otolaryngology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - J Silverman
- Department of Otolaryngology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - R Orman
- Department of Physiology & Pharmacology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - J Weedon
- Department of Statistical Design & Analysis, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - D Stefanov
- Department of Statistical Design & Analysis, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - E Savoca
- Department of Cell Biology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States; Department of Otolaryngology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - L Tordjman
- Department of Physiology & Pharmacology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - K Stiles
- Department of Cell Biology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - M Ihsan
- Department of Medicine (Division of Cardiology), State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - A Nunez
- Department of Medicine (Division of Cardiology), State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States
| | - L Guzman
- Research Initiative for Scientific Enhancement (RISE) Program, City University of New York, Medgar Evers College, 1638 Bedford Avenue, Brooklyn, New York, 11225, United States
| | - M Stewart
- Department of Physiology & Pharmacology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States; Department of Neurology, State University of New York, Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York, 11203, United States.
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39
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Goldman AM, Behr ER, Semsarian C, Bagnall RD, Sisodiya S, Cooper PN. Sudden unexpected death in epilepsy genetics: Molecular diagnostics and prevention. Epilepsia 2016; 57 Suppl 1:17-25. [PMID: 26749013 DOI: 10.1111/epi.13232] [Citation(s) in RCA: 60] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2015] [Indexed: 12/19/2022]
Abstract
Epidemiologic studies clearly document the public health burden of sudden unexpected death in epilepsy (SUDEP). Clinical and experimental studies have uncovered dynamic cardiorespiratory dysfunction, both interictally and at the time of sudden death due to epilepsy. Genetic analyses in humans and in model systems have facilitated our current molecular understanding of SUDEP. Many discoveries have been informed by progress in the field of sudden cardiac death and sudden infant death syndrome. It is becoming apparent that SUDEP genomic complexity parallels that of sudden cardiac death, and that there is a pauci1ty of analytically useful postmortem material. Because many challenges remain, future progress in SUDEP research, molecular diagnostics, and prevention rests in international, collaborative, and transdisciplinary dialogue in human and experimental translational research of sudden death.
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Affiliation(s)
- Alica M Goldman
- Department of Neurology, Baylor College of Medicine, Houston, Texas, U.S.A
| | - Elijah R Behr
- Cardiac Research Centre, ICCS, St George's University of London, London, United Kingdom
| | - Christopher Semsarian
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Richard D Bagnall
- Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney Medical School, University of Sydney, Sydney, New South Wales, Australia
| | - Sanjay Sisodiya
- Institute of Neurology, University College London, London, United Kingdom
| | - Paul N Cooper
- Department of Neurology, Greater Manchester Neurosciences Centre, Salford, United Kingdom.,University of Manchester, Manchester, United Kingdom
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40
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Pansani AP, Colugnati DB, Scorza CA, de Almeida ACG, Cavalheiro EA, Scorza FA. Furthering our understanding of SUDEP: the role of animal models. Expert Rev Neurother 2016; 16:561-72. [PMID: 27029803 DOI: 10.1586/14737175.2016.1169925] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Sudden and unexpected death in epilepsy (SUDEP) is the most common type of death among patients with epilepsy. Here, we address the importance of the experimental models in search of the mechanisms underlying SUDEP. Most studies have investigated the cardiovascular responses in animal models of epilepsy. However, there are few proposed SUDEP models in literature. Hypoventilation, apnea, respiratory distress, pulmonary hypertension, autonomic dysregulation and arrhythmia are common findings in epilepsy models. Impairments on adenosinergic and serotonergic systems, brainstem spreading depolarization, seizure-activation of neural substrates related to cardiorespiratory control, altered autonomic control, and mutations on sodium and potassium channels are hypothesis suggested. Overall, current research highlights the evident multifactorial nature of SUDEP, which involves acute and chronic aspects ranging from systemic to molecular alterations. Thus, we are convinced that elucidation and prevention of SUDEP can be achieved only through the interaction between basic and clinical science.
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Affiliation(s)
- Aline P Pansani
- a Laboratório Integrado de Fisiopatologia Cardiovascular e Neurológica. Departamento de Ciências Fisiológicas , Universidade Federal de Goiás , Goiânia , Brasil
| | - Diego B Colugnati
- a Laboratório Integrado de Fisiopatologia Cardiovascular e Neurológica. Departamento de Ciências Fisiológicas , Universidade Federal de Goiás , Goiânia , Brasil
| | - Carla A Scorza
- b Disciplina de Neurociência. Departamento de Neurologia/Neurocirurgia , Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP) , São Paulo , Brasil
| | - Antonio-Carlos G de Almeida
- c Laboratório de Neurociência Experimental e Computacional. Departamento de Engenharia de Biossistemas , Universidade Federal de São João del-Rei , São João del-Rei , Brasil
| | - Esper A Cavalheiro
- b Disciplina de Neurociência. Departamento de Neurologia/Neurocirurgia , Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP) , São Paulo , Brasil
| | - Fulvio A Scorza
- b Disciplina de Neurociência. Departamento de Neurologia/Neurocirurgia , Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP) , São Paulo , Brasil
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Edlow BL, McNab JA, Witzel T, Kinney HC. The Structural Connectome of the Human Central Homeostatic Network. Brain Connect 2016; 6:187-200. [PMID: 26530629 PMCID: PMC4827322 DOI: 10.1089/brain.2015.0378] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Homeostatic adaptations to stress are regulated by interactions between the brainstem and regions of the forebrain, including limbic sites related to respiratory, autonomic, affective, and cognitive processing. Neuroanatomic connections between these homeostatic regions, however, have not been thoroughly identified in the human brain. In this study, we perform diffusion spectrum imaging tractography using the MGH-USC Connectome MRI scanner to visualize structural connections in the human brain linking autonomic and cardiorespiratory nuclei in the midbrain, pons, and medulla oblongata with forebrain sites critical to homeostatic control. Probabilistic tractography analyses in six healthy adults revealed connections between six brainstem nuclei and seven forebrain regions, several over long distances between the caudal medulla and cerebral cortex. The strongest evidence for brainstem-homeostatic forebrain connectivity in this study was between the brainstem midline raphe and the medial temporal lobe. The subiculum and amygdala were the sampled forebrain nodes with the most extensive brainstem connections. Within the human brainstem-homeostatic forebrain connectome, we observed that a lateral forebrain bundle, whose connectivity is distinct from that of rodents and nonhuman primates, is the primary conduit for connections between the brainstem and medial temporal lobe. This study supports the concept that interconnected brainstem and forebrain nodes form an integrated central homeostatic network (CHN) in the human brain. Our findings provide an initial foundation for elucidating the neuroanatomic basis of homeostasis in the normal human brain, as well as for mapping CHN disconnections in patients with disorders of homeostasis, including sudden and unexpected death, and epilepsy.
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Affiliation(s)
- Brian L. Edlow
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts
| | - Jennifer A. McNab
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts
- Department of Radiology, R.M. Lucas Center for Imaging, Stanford University, Stanford, California
| | - Thomas Witzel
- Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts
| | - Hannah C. Kinney
- Department of Pathology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts
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Zhan Q, Buchanan GF, Motelow JE, Andrews J, Vitkovskiy P, Chen WC, Serout F, Gummadavelli A, Kundishora A, Furman M, Li W, Bo X, Richerson GB, Blumenfeld H. Impaired Serotonergic Brainstem Function during and after Seizures. J Neurosci 2016; 36:2711-22. [PMID: 26937010 PMCID: PMC4879214 DOI: 10.1523/jneurosci.4331-15.2016] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/11/2016] [Accepted: 01/23/2016] [Indexed: 12/30/2022] Open
Abstract
Impaired breathing, cardiac function, and arousal during and after seizures are important causes of morbidity and mortality. Previous work suggests that these changes are associated with depressed brainstem function in the ictal and post-ictal periods. Lower brainstem serotonergic systems are postulated to play an important role in cardiorespiratory changes during and after seizures, whereas upper brainstem serotonergic and other systems regulate arousal. However, direct demonstration of seizure-associated neuronal activity changes in brainstem serotonergic regions has been lacking. Here, we performed multiunit and single-unit recordings from medullary raphe and midbrain dorsal raphe nuclei in an established rat seizure model while measuring changes in breathing rate and depth as well as heart rate. Serotonergic neurons were identified by immunohistochemistry. Respiratory rate, tidal volume, and minute ventilation were all significantly decreased during and after seizures in this model. We found that population firing of neurons in the medullary and midbrain raphe on multiunit recordings was significantly decreased during the ictal and post-ictal periods. Single-unit recordings from identified serotonergic neurons in the medullary raphe revealed highly consistently decreased firing during and after seizures. In contrast, firing of midbrain raphe serotonergic neurons was more variable, with a mixture of increases and decreases. The markedly suppressed firing of medullary serotonergic neurons supports their possible role in simultaneously impaired cardiorespiratory function in seizures. Decreased arousal likely arises from depressed population activity of several neuronal pools in the upper brainstem and forebrain. These findings have important implications for preventing morbidity and mortality in people living with epilepsy. SIGNIFICANCE STATEMENT Seizures often cause impaired breathing, cardiac dysfunction, and loss of consciousness. The brainstem and, specifically, brainstem serotonin neurons are thought to play an important role in controlling breathing, cardiac function, and arousal. We used an established rat seizure model to study the overall neuronal activity in the brainstem as well as firing of specific serotonin neurons while measuring cardiorespiratory function. Our results demonstrated overall decreases in brainstem neuronal activity and marked downregulation of lower brainstem serotonin neuronal firing in association with decreased breathing and heart rate during and after seizures. These findings point the way toward new treatments to augment brainstem function and serotonin, aiming to prevent seizure complications and reduce morbidity and mortality in people living with epilepsy.
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Affiliation(s)
- Qiong Zhan
- Departments of Neurology, Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China, Department of Neurology, the Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | | | | | | | | | | | | | | | | | | | - Wei Li
- Departments of Neurology, Department of Neurosurgery, Jinling Hospital, School of Medicine Nanjing University, Nanjing Jiangsu 210002, China, and
| | - Xiao Bo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, Hunan 410008, China
| | - George B Richerson
- Departments of Neurology and Molecular Physiology and Biophysics, and Veterans Affairs Medical Center, Iowa City, Iowa 52246
| | - Hal Blumenfeld
- Departments of Neurology, Neuroscience, and Neurosurgery, Yale University School of Medicine, New Haven, Connecticut 06520,
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Hajek MA, Buchanan GF. Influence of vigilance state on physiological consequences of seizures and seizure-induced death in mice. J Neurophysiol 2016; 115:2286-93. [PMID: 26888097 DOI: 10.1152/jn.00011.2016] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/13/2016] [Indexed: 12/31/2022] Open
Abstract
Sudden unexpected death in epilepsy (SUDEP) is the leading cause of death in patients with refractory epilepsy. SUDEP occurs more commonly during nighttime sleep. The details of why SUDEP occurs at night are not well understood. Understanding why SUDEP occurs at night during sleep might help to better understand why SUDEP occurs at all and hasten development of preventive strategies. Here we aimed to understand circumstances causing seizures that occur during sleep to result in death. Groups of 12 adult male mice were instrumented for EEG, EMG, and EKG recording and subjected to seizure induction via maximal electroshock (MES) during wakefulness, nonrapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep. Seizure inductions were performed with concomitant EEG, EMG, and EKG recording and breathing assessment via whole body plethysmography. Seizures induced via MES during sleep were associated with more profound respiratory suppression and were more likely to result in death. Despite REM sleep being a time when seizures do not typically occur spontaneously, when seizures were forced to occur during REM sleep, they were invariably fatal in this model. An examination of baseline breathing revealed that mice that died following a seizure had increased baseline respiratory rate variability compared with those that did not die. These data demonstrate that sleep, especially REM sleep, can be a dangerous time for a seizure to occur. These data also demonstrate that there may be baseline respiratory abnormalities that can predict which individuals have higher risk for seizure-induced death.
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Affiliation(s)
- Michael A Hajek
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut
| | - Gordon F Buchanan
- Department of Neurology, Yale School of Medicine, New Haven, Connecticut; Veterans Affairs Medical Center, West Haven, Connecticut; and Department of Neurology, University of Iowa Carver College of Medicine, Iowa City, Iowa
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44
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Aiba I, Noebels JL. Spreading depolarization in the brainstem mediates sudden cardiorespiratory arrest in mouse SUDEP models. Sci Transl Med 2016; 7:282ra46. [PMID: 25855492 DOI: 10.1126/scitranslmed.aaa4050] [Citation(s) in RCA: 205] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Cardiorespiratory collapse after a seizure is the leading cause of sudden unexpected death in epilepsy (SUDEP) in young persons, but why only certain individuals are at risk is unknown. To identify a mechanism for this lethal cardiorespiratory failure, we examined whether genes linked to increased SUDEP risk lower the threshold for spreading depolarization (SD), a self-propagating depolarizing wave that silences neuronal networks. Mice carrying mutations in Kv1.1 potassium channels (-/-) and Scn1a sodium ion channels (+/R1407X) phenocopy many aspects of human SUDEP. In mutant, but not wild-type mice, seizures initiated by topical application of 4-aminopyridine to the cortex led to a slow, negative DC potential shift recorded in the dorsal medulla, a brainstem region that controls cardiorespiratory pacemaking. This irreversible event slowly depolarized cells and inactivated synaptic activity, producing cardiorespiratory arrest. Local initiation of SD in this region by potassium chloride microinjection also elicited electroencephalographic suppression, apnea, bradycardia, and asystole, similar to the events seen in monitored human SUDEP. In vitro study of brainstem slices confirmed that mutant mice had a lower threshold for SD elicited by metabolic substrate depletion and that immature mice were at greater risk than adults. Deletion of the gene encoding tau, which prolongs life in these mutants, also restored the normal SD threshold in Kv1.1-mutant mouse brainstem. Thus, brainstem SD may be a critical threshold event linking seizures and SUDEP.
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Affiliation(s)
- Isamu Aiba
- Developmental Neurogenetics Laboratory, Department of Neurology, and NIH/NINDS Center for SUDEP Research, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jeffrey L Noebels
- Developmental Neurogenetics Laboratory, Department of Neurology, and NIH/NINDS Center for SUDEP Research, Baylor College of Medicine, Houston, TX 77030, USA. Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA. Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
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45
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Richerson GB, Boison D, Faingold CL, Ryvlin P. From unwitnessed fatality to witnessed rescue: Pharmacologic intervention in sudden unexpected death in epilepsy. Epilepsia 2016; 57 Suppl 1:35-45. [PMID: 26749015 PMCID: PMC4890608 DOI: 10.1111/epi.13236] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2015] [Indexed: 12/11/2022]
Abstract
The mechanisms of sudden unexpected death in epilepsy (SUDEP) have been difficult to define, as most cases occur unwitnessed, and physiologic recordings have been obtained in only a handful of cases. However, recent data obtained from human cases and experimental studies in animal models have brought us closer to identifying potential mechanisms. Theories of SUDEP should be able to explain how a seizure starting in the forebrain can sometimes lead to changes in brainstem cardiorespiratory control mechanisms. Herein we focus on three major themes of work on the causes of SUDEP. First, evidence is reviewed identifying postictal hypoventilation as a major contributor to the cause of death. Second, data are discussed that brainstem serotonin and adenosine pathways may be involved, as well as how they may contribute. Finally, parallels are drawn between SIDS and SUDEP, and we highlight similarities pointing to the possibility of shared pathophysiology involving combined failure of respiratory and cardiovascular control mechanisms. Knowledge about the causes of SUDEP may lead to potential pharmacologic approaches for prevention. We end by describing how translation of this work may result in future applications to clinical care.
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Affiliation(s)
- George B Richerson
- Departments of Neurology and Molecular Physiology & Biophysics, University of Iowa & Veteran's Affairs Medical Center, Iowa City, Iowa, U.S.A
| | - Detlev Boison
- Robert Stone Dow Neurobiology Laboratories, Legacy Research Institute Portland, Portland, Oregon, U.S.A
| | - Carl L Faingold
- Departments of Pharmacology and Neurology and Division of Neurosurgery, Southern Illinois University School of Medicine, Springfield, Illinois, U.S.A
| | - Philippe Ryvlin
- Department of Clinical Neurosciences, Lausanne University Hospital, Lausanne, Switzerland
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Inhibition of adenosine metabolism induces changes in post-ictal depression, respiration, and mortality in genetically epilepsy prone rats. Epilepsy Res 2016; 119:13-9. [DOI: 10.1016/j.eplepsyres.2015.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Revised: 09/10/2015] [Accepted: 11/05/2015] [Indexed: 11/17/2022]
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47
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Siniscalchi A, Scaglione F, Sanzaro E, Iemolo F, Albertini G, Quirino G, Manes MT, Gratteri S, Mercuri NB, De Sarro G, Gallelli L. Effects of phenobarbital and levetiracetam on PR and QTc intervals in patients with post-stroke seizure. Clin Drug Investig 2015; 34:879-86. [PMID: 25385363 DOI: 10.1007/s40261-014-0243-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
BACKGROUND AND OBJECTIVES Sudden unexplained/unexpected death (SUDEP) is related to high mortality in patients with epilepsy. The prolongation of QT interval, involved in cardiac arrhythmia-related SUDEP, may be precipitated by antiepileptic drugs (AEDs). In this study, we evaluated the effects of phenobarbital and levetiracetam on PR-QTc intervals in patients with post-stroke seizures. METHODS We performed an open-label, parallel group, prospective, multicenter study between June 2009 and December 2013 in patients older than 18 years of age with a clinical diagnosis of post-stroke seizure and treated with phenobarbital or levetiracetam. In order to exclude a role of cerebral post-stroke injury on modulation of PR and QTc intervals, patients with cerebral post-stroke injury and without seizures were also enrolled as controls. RESULTS Interictal electrocardiography analysis revealed no significant difference in PR interval between patients treated with an AED (n = 49) and control patients (n = 50) (181.25 ± 12.05 vs. 182.4 ± 10.3 ms; p > 0.05). In contrast, a significantly longer QTc interval was recorded in patients treated with an AED compared with control patients (441.2 ± 56.6 vs. 396.8 ± 49.3 ms; p < 0.01). Patients treated with phenobarbital showed a significantly longer QTc interval than patients treated with levetiracetam (460.0 ± 57.2 vs. 421.5 ± 50.1 ms; p < 0.05). CONCLUSIONS The study reported that in patients with late post-stroke seizures, phenobarbital prolonged QTc interval more so than levetiracetam.
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48
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Smithson WH, Colwell B, Hanna J. Sudden unexpected death in epilepsy: addressing the challenges. Curr Neurol Neurosci Rep 2015; 14:502. [PMID: 25300243 PMCID: PMC4192556 DOI: 10.1007/s11910-014-0502-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Epilepsy is associated with a higher rate of premature death than the general population, and the commonest cause of epilepsy mortality is sudden unexpected death in epilepsy (SUDEP). It is difficult to quantify because of the variable reporting of this cause of death. Death occurs due to autonomic deregulation of cardio-respiratory pathways as a result of seizures. Measures to reduce cardio-respiratory dysfunction are discussed together with the importance of seizure control in preventing SUDEP. The role of seizure detection devices, antiepileptic drugs and the importance of providing information about SUDEP to people with epilepsy are highlighted. There is increasing interest in SUDEP and some current initiatives are discussed.
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Affiliation(s)
- W Henry Smithson
- Department of General Practice, University College Cork Ireland, Western Gateway Building, Western Road, Cork, Ireland,
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49
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Buchanan GF, Smith HR, MacAskill A, Richerson GB. 5-HT2A receptor activation is necessary for CO2-induced arousal. J Neurophysiol 2015; 114:233-43. [PMID: 25925320 DOI: 10.1152/jn.00213.2015] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2015] [Accepted: 04/29/2015] [Indexed: 11/22/2022] Open
Abstract
Hypercapnia-induced arousal from sleep is an important protective mechanism pertinent to a number of diseases. Most notably among these are the sudden infant death syndrome, obstructive sleep apnea and sudden unexpected death in epilepsy. Serotonin (5-HT) plays a significant role in hypercapnia-induced arousal. The mechanism of 5-HT's role in this protective response is unknown. Here we sought to identify the specific 5-HT receptor subtype(s) involved in this response. Wild-type mice were pretreated with antagonists against 5-HT receptor subtypes, as well as antagonists against adrenergic, cholinergic, histaminergic, dopaminergic, and orexinergic receptors before challenge with inspired CO2 or hypoxia. Antagonists of 5-HT(2A) receptors dose-dependently blocked CO2-induced arousal. The 5-HT(2C) receptor antagonist, RS-102221, and the 5-HT1A receptor agonist, 8-OH-DPAT, attenuated but did not completely block CO2-induced arousal. Blockade of non-5-HT receptors did not affect CO2-induced arousal. None of these drugs had any effect on hypoxia-induced arousal. 5-HT2 receptor agonists were given to mice in which 5-HT neurons had been genetically eliminated during embryonic life (Lmx1b(f/f/p)) and which are known to lack CO2-induced arousal. Application of agonists to 5-HT(2A), but not 5-HT(2C), receptors, dose-dependently restored CO2-induced arousal in these mice. These data identify the 5-HT(2A) receptor as an important mediator of CO2-induced arousal and suggest that, while 5-HT neurons can be independently activated to drive CO2-induced arousal, in the absence of 5-HT neurons and endogenous 5-HT, 5-HT receptor activation can act in a permissive fashion to facilitate CO2-induced arousal via another as yet unidentified chemosensor system.
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Affiliation(s)
- Gordon F Buchanan
- Department of Neurology, Yale University, New Haven, Connecticut; Veteran's Affairs Medical Center, West Haven, Connecticut; Department of Neurology, University of Iowa, Iowa City, Iowa;
| | - Haleigh R Smith
- Department of Neurology, Yale University, New Haven, Connecticut
| | - Amanda MacAskill
- University of Glasgow School of Medicine, Glasgow, Scotland, United Kingdom
| | - George B Richerson
- Department of Neurology, Yale University, New Haven, Connecticut; Department of Neurology, University of Iowa, Iowa City, Iowa; Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, Iowa; and Veteran's Affairs Medical Center, Iowa City, Iowa
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50
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Mulkey DK, Hawkins VE, Hawryluk JM, Takakura AC, Moreira TS, Tzingounis AV. Molecular underpinnings of ventral surface chemoreceptor function: focus on KCNQ channels. J Physiol 2015; 593:1075-81. [PMID: 25603782 DOI: 10.1113/jphysiol.2014.286500] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 01/12/2015] [Indexed: 12/12/2022] Open
Abstract
Central chemoreception is the mechanism by which CO₂/H(+) -sensitive neurons (i.e. chemoreceptors) regulate breathing in response to changes in tissue CO₂/H(+) . Neurons in the retrotrapezoid nucleus (RTN) directly regulate breathing in response to changes in tissue CO₂/H(+) and function as a key locus of respiratory control by integrating information from several respiratory centres, including the medullary raphe. Therefore, chemosensitive RTN neurons appear to be critically important for maintaining breathing, thus understanding molecular mechanisms that regulate RTN chemoreceptor function may identify therapeutic targets for the treatment of respiratory control disorders. We have recently shown that KCNQ (Kv7) channels in the RTN are essential determinants of spontaneous activity ex vivo, and downstream effectors for serotonergic modulation of breathing. Considering that loss of function mutations in KCNQ channels can cause certain types of epilepsy including those associated with sudden unexplained death in epilepsy (SUDEP), we propose that dysfunctions of KCNQ channels may be one cause for epilepsy and respiratory problems associated with SUDEP. In this review, we will summarize the role of KCNQ channels in the regulation of RTN chemoreceptor function, and suggest that these channels represent useful therapeutic targets for the treatment of respiratory control disorders.
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Affiliation(s)
- Daniel K Mulkey
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, CT, 06269, USA
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