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Welzel B, Johne M, Löscher W. Bumetanide potentiates the anti-seizure and disease-modifying effects of midazolam in a noninvasive rat model of term birth asphyxia. Epilepsy Behav 2023; 142:109189. [PMID: 37037061 DOI: 10.1016/j.yebeh.2023.109189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 04/12/2023]
Abstract
Birth asphyxia and the resulting hypoxic-ischemic encephalopathy (HIE) are highly associated with perinatal and neonatal death, neonatal seizures, and an adverse later-life outcome. Currently used drugs, including phenobarbital and midazolam, have limited efficacy to suppress neonatal seizures. There is a medical need to develop new therapies that not only suppress neonatal seizures but also prevent later-life consequences. We have previously shown that the loop diuretic bumetanide does not potentiate the effects of phenobarbital in a rat model of birth asphyxia. Here we compared the effects of bumetanide (0.3 or 10 mg/kg i.p.), midazolam (1 mg/kg i.p.), and a combination of bumetanide and midazolam on neonatal seizures and later-life outcomes in this model. While bumetanide at either dose was ineffective when administered alone, the higher dose of bumetanide markedly potentiated midazolam's effect on neonatal seizures. Median bumetanide brain levels (0.47-0.53 µM) obtained with the higher dose were in the range known to inhibit the Na-K-Cl-cotransporter NKCC1 but it remains to be determined whether brain NKCC1 inhibition was underlying the potentiation of midazolam. When behavioral and cognitive alterations were examined over three months after asphyxia, treatment with the bumetanide/midazolam combination, but not with bumetanide or midazolam alone, prevented impairment of learning and memory. Furthermore, the combination prevented the loss of neurons in the dentate hilus and aberrant mossy fiber sprouting in the CA3a area of the hippocampus. The molecular mechanisms that explain that bumetanide potentiates midazolam but not phenobarbital in the rat model of birth asphyxia remain to be determined.
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Affiliation(s)
- Björn Welzel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany
| | - Marie Johne
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany.
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2
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Waak M, Laing J, Nagarajan L, Lawn N, Harvey AS. Continuous electroencephalography in the intensive care unit: A critical review and position statement from an Australian and New Zealand perspective. CRIT CARE RESUSC 2023; 25:9-19. [PMID: 37876987 PMCID: PMC10581281 DOI: 10.1016/j.ccrj.2023.04.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2023]
Abstract
Objectives This article aims to critically review the literature on continuous electroencephalography (cEEG) monitoring in the intensive care unit (ICU) from an Australian and New Zealand perspective and provide recommendations for clinicians. Design and review methods A taskforce of adult and paediatric neurologists, selected by the Epilepsy Society of Australia, reviewed the literature on cEEG for seizure detection in critically ill neonates, children, and adults in the ICU. The literature on routine EEG and cEEG for other indications was not reviewed. Following an evaluation of the evidence and discussion of controversial issues, consensus was reached, and a document that highlighted important clinical, practical, and economic considerations regarding cEEG in Australia and New Zealand was drafted. Results This review represents a summary of the literature and consensus opinion regarding the use of cEEG in the ICU for detection of seizures, highlighting gaps in evidence, practical problems with implementation, funding shortfalls, and areas for future research. Conclusion While cEEG detects electrographic seizures in a significant proportion of at-risk neonates, children, and adults in the ICU, conferring poorer neurological outcomes and guiding treatment in many settings, the health economic benefits of treating such seizures remain to be proven. Presently, cEEG in Australian and New Zealand ICUs is a largely unfunded clinical resource that is subsequently reserved for the highest-impact patient groups. Wider adoption of cEEG requires further research into impact on functional and health economic outcomes, education and training of the neurology and ICU teams involved, and securement of the necessary resources and funding to support the service.
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Affiliation(s)
- Michaela Waak
- Paediatric Critical Care Research Group, Child Health Research Centre, The University of Queensland, Brisbane, Australia
- Paediatric Intensive Care Unit, Queensland Children's Hospital, South Brisbane, Australia
| | - Joshua Laing
- Department of Neurosciences, Central Clinical School, Monash University, Melbourne, Australia
- Comprehensive Epilepsy Program, Alfred Health, Melbourne, Australia
- Department of Neurology, The Royal Melbourne Hospital, Melbourne, Australia
| | - Lakshmi Nagarajan
- Department of Neurology, Perth Children's Hospital, Perth, Australia
- Faculty of Health and Medical Sciences, University of Western Australia, Perth, Australia
- Telethon Kids Institute, Perth Children's Hospital, Perth, Australia
| | - Nicholas Lawn
- Western Australian Adult Epilepsy Service, Sir Charles Gardiner Hospital, Perth, Australia
| | - A. Simon Harvey
- Department of Neurology, The Royal Children's Hospital, Melbourne, Australia
- Department of Paediatrics, The University of Melbourne, Melbourne, Australia
- Neurosciences Research Group, Murdoch Children's Research Institute, Melbourne, Australia
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3
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Welzel B, Schmidt R, Johne M, Löscher W. Midazolam Prevents the Adverse Outcome of Neonatal Asphyxia. Ann Neurol 2023; 93:226-243. [PMID: 36054632 DOI: 10.1002/ana.26498] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 08/09/2022] [Accepted: 08/29/2022] [Indexed: 01/31/2023]
Abstract
OBJECTIVE Birth asphyxia (BA) is the most frequent cause of neonatal death as well as central nervous system (CNS) injury. BA is often associated with neonatal seizures, which only poorly respond to anti-seizure medications and may contribute to the adverse neurodevelopmental outcome. Using a non-invasive rat model of BA, we have recently reported that the potent benzodiazepine, midazolam, prevents neonatal seizures in ~50% of rat pups. In addition to its anti-seizure effect, midazolam exerts anti-inflammatory actions, which is highly relevant for therapeutic intervention following BA. The 2 major aims of the present study were to examine (1) whether midazolam reduces the adverse outcome of BA, and (2) whether this effect is different in rats that did or did not exhibit neonatal seizures after drug treatment. METHODS Behavioral and cognitive tests were performed over 14 months after asphyxia, followed by immunohistochemical analyses. RESULTS All vehicle-treated rats had seizures after asphyxia and developed behavioral and cognitive abnormalities, neuroinflammation in gray and white matter, neurodegeneration in the hippocampus and thalamus, and hippocampal mossy fiber sprouting in subsequent months. Administration of midazolam (1 mg/kg i.p.) directly after asphyxia prevented post-asphyctic seizures in ~50% of the rats and resulted in the prevention or decrease of neuroinflammation and the behavioral, cognitive, and neurodegenerative consequences of asphyxia. Except for neurodegeneration in the thalamus, seizures did not seem to contribute to the adverse outcome of asphyxia. INTERPRETATION The disease-modifying effect of midazolam identified here strongly suggests that this drug provides a valuable option for improving the treatment and outcome of BA. ANN NEUROL 2023;93:226-243.
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Affiliation(s)
- Björn Welzel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Ricardo Schmidt
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Marie Johne
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
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Cerebroprotective actions of hydrogen sulfide in the epileptic brain in newborn pigs. Pediatr Res 2023:10.1038/s41390-023-02486-5. [PMID: 36694027 PMCID: PMC10363572 DOI: 10.1038/s41390-023-02486-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 12/23/2022] [Accepted: 01/01/2023] [Indexed: 01/26/2023]
Abstract
BACKGROUND Neonatal epileptic seizures cause postictal dysregulation of cerebral blood flow. Hydrogen sulfide (H2S), a mediator with vasodilator and antioxidant properties, is produced in the brain by astrocyte cystathionine β-synthase (CBS). This study investigated whether H2S improves the cerebral vascular outcome of seizures. METHODS Epileptic seizures were induced in newborn pigs using bicuculline. The effects of the CBS inhibitor aminooxyacetate (AOA) and the H2S donor NaHS on cerebral vascular outcome of seizures were examined in live pigs, cerebral endothelial cells, and cortical astrocytes. RESULTS Brain H2S was elevated during seizures. AOA blocked H2S and reduced functional hyperemia in the epileptic brain. The endothelium- and astrocyte-dependent vasodilation of pial arterioles was impaired 48 h after seizures suggesting cerebral vascular dysfunction. Systemic NaHS elevated brain H2S and blocked reactive oxygen species in the epileptic brain and in primary endothelial cells and astrocytes during inflammatory and excitotoxic conditions. Postictal cerebrovascular dysfunction was exaggerated in H2S-inhibited pigs and minimized in NaHS-treated pigs. CONCLUSIONS H2S elevation in the epileptic brain via activation of CBS contributes to functional hyperemia and exhibits cerebroprotective properties. The H2S donor NaHS enhances brain antioxidant defense and provides a therapeutic approach for preventing adverse cerebral vascular outcome of neonatal epileptic seizures. IMPACT Epileptic seizures in neonates lead to prolonged postictal cerebral vascular dysregulation. The role of hydrogen sulfide (H2S), a mediator with vasodilator and antioxidant properties, in the epileptic brain has been explored. Astrocytes are major sites of enzymatic H2S production in the epileptic brain. Postictal cerebral vascular dysfunction is exaggerated when astrocyte H2S production is pharmacologically inhibited during seizures. Postictal cerebral vascular dysfunction is minimized when the brain H2S is elevated by systemic administration of NaHS during seizures. NaHS provides a therapeutic approach for improving cerebrovascular outcome of epileptic seizures via a mechanism that involves the antioxidant potential of H2S.
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Gailus B, Naundorf H, Welzel L, Johne M, Römermann K, Kaila K, Löscher W. Long-term outcome in a noninvasive rat model of birth asphyxia with neonatal seizures: Cognitive impairment, anxiety, epilepsy, and structural brain alterations. Epilepsia 2021; 62:2826-2844. [PMID: 34458992 DOI: 10.1111/epi.17050] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/30/2021] [Accepted: 08/09/2021] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Birth asphyxia is a major cause of hypoxic-ischemic encephalopathy (HIE) in neonates and often associated with mortality, neonatal seizures, brain damage, and later life motor, cognitive, and behavioral impairments and epilepsy. Preclinical studies on rodent models are needed to develop more effective therapies for preventing HIE and its consequences. Thus far, the most popular rodent models have used either exposure of intact animals to hypoxia-only, or a combination of hypoxia and carotid occlusion, for the induction of neonatal seizures and adverse outcomes. However, such models lack systemic hypercapnia, which is a fundamental constituent of birth asphyxia with major effects on neuronal excitability. Here, we use a recently developed noninvasive rat model of birth asphyxia with subsequent neonatal seizures to study later life adverse outcome. METHODS Intermittent asphyxia was induced for 30 min by exposing male and female postnatal day 11 rat pups to three 7 + 3-min cycles of 9% and 5% O2 at constant 20% CO2 . All pups exhibited convulsive seizures after asphyxia. A set of behavioral tests were performed systematically over 14 months following asphyxia, that is, a large part of the rat's life span. Video-electroencephalographic (EEG) monitoring was used to determine whether asphyxia led to the development of epilepsy. Finally, structural brain alterations were examined. RESULTS The animals showed impaired spatial learning and memory and increased anxiety when tested at an age of 3-14 months. Video-EEG at ~10 months showed an abundance of spontaneous seizures, which was paralleled by neurodegeneration in the hippocampus and thalamus, and by aberrant mossy fiber sprouting. SIGNIFICANCE The present model of birth asphyxia recapitulates several of the later life consequences associated with human HIE. This model thus allows evaluation of the efficacy of novel therapies designed to prevent HIE and seizures following asphyxia, and of how such therapies might alleviate long-term adverse consequences.
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Affiliation(s)
- Björn Gailus
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Hannah Naundorf
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Lisa Welzel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Marie Johne
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Kerstin Römermann
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, Helsinki, Finland.,Neuroscience Center (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
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6
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Postnikova TY, Griflyuk AV, Amakhin DV, Kovalenko AA, Soboleva EB, Zubareva OE, Zaitsev AV. Early Life Febrile Seizures Impair Hippocampal Synaptic Plasticity in Young Rats. Int J Mol Sci 2021; 22:8218. [PMID: 34360983 PMCID: PMC8347828 DOI: 10.3390/ijms22158218] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/04/2023] Open
Abstract
Febrile seizures (FSs) in early life are significant risk factors of neurological disorders and cognitive impairment in later life. However, existing data about the impact of FSs on the developing brain are conflicting. We aimed to investigate morphological and functional changes in the hippocampus of young rats exposed to hyperthermia-induced seizures at postnatal day 10. We found that FSs led to a slight morphological disturbance. The cell numbers decreased by 10% in the CA1 and hilus but did not reduce in the CA3 or dentate gyrus areas. In contrast, functional impairments were robust. Long-term potentiation (LTP) in CA3-CA1 synapses was strongly reduced, which we attribute to the insufficient activity of N-methyl-D-aspartate receptors (NMDARs). Using whole-cell recordings, we found higher desensitization of NMDAR currents in the FS group. Since the desensitization of NMDARs depends on subunit composition, we analyzed NMDAR current decays and gene expression of subunits, which revealed no differences between control and FS rats. We suggest that an increased desensitization is due to insufficient activation of the glycine site of NMDARs, as the application of D-serine, the glycine site agonist, allows the restoration of LTP to a control value. Our results reveal a new molecular mechanism of FS impact on the developing brain.
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Affiliation(s)
| | | | | | | | | | | | - Aleksey V. Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, 44, Toreza Prospekt, 194223 Saint Petersburg, Russia; (T.Y.P.); (A.V.G.); (D.V.A.); (A.A.K.); (E.B.S.); (O.E.Z.)
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7
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Ziobro JM, Eschbach K, Shellhaas RA. Novel Therapeutics for Neonatal Seizures. Neurotherapeutics 2021; 18:1564-1581. [PMID: 34386906 PMCID: PMC8608938 DOI: 10.1007/s13311-021-01085-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2021] [Indexed: 02/04/2023] Open
Abstract
Neonatal seizures are a common neurologic emergency for which therapies have not significantly changed in decades. Improvements in diagnosis and pathophysiologic understanding of the distinct features of acute symptomatic seizures and neonatal-onset epilepsies present exceptional opportunities for development of precision therapies with potential to improve outcomes. Herein, we discuss the pathophysiology of neonatal seizures and review the evidence for currently available treatment. We present emerging therapies in clinical and preclinical development for the treatment of acute symptomatic neonatal seizures. Lastly, we discuss the role of precision therapies for genetic neonatal-onset epilepsies and address barriers and goals for developing new therapies for clinical care.
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Affiliation(s)
- Julie M Ziobro
- Department of Pediatrics, Michigan Medicine, C.S. Mott Children's Hospital, University of Michigan, 1540 E. Hospital Dr, Ann Arbor, MI, USA.
| | - Krista Eschbach
- Department of Pediatrics, Section of Neurology, Denver Anschutz School of Medicine, Children's Hospital Colorado, University of Colorado, Aurora, CO, 80045, USA
| | - Renée A Shellhaas
- Department of Pediatrics, Michigan Medicine, C.S. Mott Children's Hospital, University of Michigan, 1540 E. Hospital Dr, Ann Arbor, MI, USA
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8
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Macdonald-Laurs E, Sharpe C, Nespeca M, Rismanchi N, Gold JJ, Kuperman R, Wang S, Lee NMD, Michelson DJ, Haas R, Reed P, Davis SL. Does the first hour of continuous electroencephalography predict neonatal seizures? Arch Dis Child Fetal Neonatal Ed 2021; 106:162-167. [PMID: 32928896 DOI: 10.1136/archdischild-2020-318985] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 07/18/2020] [Accepted: 07/26/2020] [Indexed: 01/22/2023]
Abstract
OBJECTIVE Prolonged continuous video-electroencephalography (cEEG) is recommended for neonates at risk of seizures. The cost and expertise required to provide a real-time response to detected seizures often limits its utility. We hypothesised that the first hour of cEEG could predict subsequent seizures. DESIGN AND SETTING Retrospective multicentre diagnostic accuracy study. PATIENTS 266 term neonates at risk of seizure or with suspected seizures. INTERVENTION The first hour of cEEG was graded by expert and novice interpreters as normal, mildly, moderately or severely abnormal; seizures were identified. MAIN OUTCOME MEASURES Association between abnormalities in the first hour of cEEG and the presence of seizures during total cEEG monitoring. RESULTS 50/98 (51%) of neonates who developed seizures had their first seizure in the first hour of cEEG monitoring. The 'time-to-event' risk of seizure from 0 to 96 hours was 0.38 (95% CI 0.32 to 0.44) while the risk in the first hour was 0.19 (95% CI 0.15 to 0.24). cEEG background was normal in 48% of neonates, mildly abnormal in 30%, moderately abnormal in 13% and severely abnormal in 9%. Inter-rater agreement for determination of background was very good (weighted kappa=0.81, 95% CI 0.72 to 0.91). When neonates with seizures during the first hour were excluded, an abnormal background resulted in 2.4 times increased risk of seizures during the subsequent monitoring period (95% CI 1.3 to 4.4, p<0.003) while a severely abnormal background resulted in a sevenfold increased risk (95% CI 3.4 to 14.3, p<0.0001). CONCLUSIONS The first hour of cEEG in at-risk neonates is useful in identifying and predicting whether seizures occur during cEEG monitoring up to 96 hours. This finding enables identification of high-risk neonates who require closer observation.
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Affiliation(s)
- Emma Macdonald-Laurs
- The Department of Paediatric Neurology, Starship Children's Health, Newmarket, New Zealand
| | - Cynthia Sharpe
- The Department of Paediatric Neurology, Starship Children's Health, Newmarket, New Zealand
| | - Mark Nespeca
- The Department of Neurosciences, Rady Children's Hospital San Diego, San Diego, California, USA.,The Department of Neurosciences, University of California San Diego, La Jolla, California, USA
| | - Neggy Rismanchi
- The Department of Neurosciences, Rady Children's Hospital San Diego, San Diego, California, USA.,The Department of Neurosciences, University of California San Diego, La Jolla, California, USA
| | - Jeffrey J Gold
- The Department of Neurosciences, Rady Children's Hospital San Diego, San Diego, California, USA.,The Department of Neurosciences, University of California San Diego, La Jolla, California, USA
| | - Rachel Kuperman
- The Department of Pediatric Neurology, UCSF Benioff Children's Hospital Oakland, Oakland, California, USA
| | - Sonya Wang
- The Department of Neurosciences, Rady Children's Hospital San Diego, San Diego, California, USA.,The Department of Neurosciences, University of California San Diego, La Jolla, California, USA
| | - Ngoc Minh D Lee
- The Department of Neurosciences, Rady Children's Hospital San Diego, San Diego, California, USA.,The Department of Neurosciences, Sharp Mary Birch Hospital for Women and Newborns, San Diego, California, USA
| | - David J Michelson
- Division of Pediatric Neurology, Loma Linda University Medical Center, Loma Linda, California, USA
| | - Richard Haas
- The Department of Neurosciences, Rady Children's Hospital San Diego, San Diego, California, USA.,The Department of Neurosciences, University of California San Diego, La Jolla, California, USA
| | - Peter Reed
- The Department of Paediatric Neurology, Starship Children's Health, Newmarket, New Zealand
| | - Suzanne L Davis
- The Department of Paediatric Neurology, Starship Children's Health, Newmarket, New Zealand
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9
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Pembegul Yıldız E, Tatlı B, Ulak Ozkan M, Erarslan E, Aydınlı N, Çalışkan M, Özmen M. Evaluation of the prognostic factors in school age children who experienced neonatal seizures. Epilepsy Behav 2020; 102:106673. [PMID: 31770716 DOI: 10.1016/j.yebeh.2019.106673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 10/17/2019] [Accepted: 10/17/2019] [Indexed: 11/16/2022]
Abstract
BACKGROUND This prospective study aimed to evaluate long-term neurodevelopmental outcomes and risk factors of the previously reported cohort, at their school age. METHOD We included neonates whose seizures were directly observed by the child neurologist or neonatologist based on clinical observations. They were assessed for cognitive and neurological outcomes at the age of 9-11 years. The test battery included a neurological examination, the Wechsler Intelligence Scale for Children-Revised (WISC-R) test, and patients with the diagnosis of cerebral palsy (CP) were graded according to the Gross Motor Function Classification System (GMFCS). The primary outcome of this study was to determine risk factors for the long-term prognosis of neonatal seizures. RESULTS For the long-term follow-up, 97 out of 112 patients of the initial cohort were available (86.6%). We found that 40 patients (41%) have the normal prognosis, 22 patients (22.7%) have the diagnosis of CP, and 30 patients (30.9%) were diagnosed as having epilepsy. Twelve out of 22 patients with CP had the diagnosis of epilepsy. The WISC-R full-scale IQ scores were <55 points in 27 patients (27.8%) and were >85 points in 40 patients (41.2%). According to GMFCS, 10 patients were classified as levels 1-2, and 12 patients were classified as levels 3-5. In multivariate regression analyses, 5-min APGAR score <6 was found to be an independent risk factor for CP, and 5-min APGAR score <6 and neonatal status epilepticus were independent risk factors for epilepsy. CONCLUSIONS This prospective cohort study reveals that abnormal school age outcome after neonatal seizures are significantly related to 5-min APGAR score <6 and neonatal status epilepticus.
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Affiliation(s)
| | - Burak Tatlı
- Department of Pediatric Neurology, Istanbul Medical Faculty, Turkey
| | - Melis Ulak Ozkan
- Department of Pediatric Neurology, Istanbul Medical Faculty, Turkey
| | - Emine Erarslan
- Department of Pediatric Neurology, Istanbul Medical Faculty, Turkey
| | - Nur Aydınlı
- Department of Pediatric Neurology, Istanbul Medical Faculty, Turkey
| | - Mine Çalışkan
- Department of Pediatric Neurology, Istanbul Medical Faculty, Turkey
| | - Meral Özmen
- Department of Pediatric Neurology, Istanbul Medical Faculty, Turkey
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10
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Kang SK, Ammanuel S, Adler DA, Kadam SD. Rescue of PB-resistant neonatal seizures with single-dose of small-molecule TrkB antagonist show long-term benefits. Epilepsy Res 2019; 159:106249. [PMID: 31864171 DOI: 10.1016/j.eplepsyres.2019.106249] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Revised: 12/02/2019] [Accepted: 12/06/2019] [Indexed: 12/14/2022]
Abstract
A recently characterized CD-1 mouse model of phenobarbital (PB)-resistant neonatal ischemic-seizures (i.e.; unilateral carotid ligation) was shown to be associated with age-dependent (P7 vs. P10) acute seizure severity and PB-efficacy (i.e.; PB-resistant vs. PB-responsive). ANA12, a novel small-molecule TrkB antagonist, rescued the PB-resistance at P7 in a dose-dependent manner and prevented the post-ischemic downregulation of KCC2, the chief Cl- extruder in neurons. The long-term consequences of this novel rescue-intervention with ANA12 + PB in P7 and P10 ligated pups was investigated and compared to the standard first-line protocol of PB-alone loading dose. The mice underwent neurobehavioral testing, 24 h video-EEG-EMG monitoring, and immunohistochemistry in ipsi- and contralateral cortices as adults following the neonatal interventions. ANA12 + PB rescued the emergence of hyperactivity in post-ischemic P7, but not in P10 pups as adults. ANA12 + PB administration at neither P7 nor P10 significantly altered 24 h macro-sleep architecture in adults when compared to PB-alone. Behavioral state-dependent gamma (35-50 Hz) power homeostasis showed the most significant between-group differences that were age-dependent. ANA12 + PB treatment, but not PB-alone, rescued the loss of gamma power homeostasis present in P7 ligate-control but absent in P10 ligate group, highlighting the age-dependence. In contrast, PB-alone treatment, but not ANA12+PB, significantly reduced the elevated delta-AUC observed in P10 ligate-controls, when PB is efficacious by itself. These results indicate that the rescue of acute PB-resistant neonatal seizures using a novel intervention positively modulates the long-term outcomes at P7 when the seizures are refractory.
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Affiliation(s)
- S K Kang
- Department of Neuroscience, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA
| | - S Ammanuel
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
| | - D A Adler
- Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21205, USA
| | - S D Kadam
- Department of Neuroscience, Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA; Departments of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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11
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Abdi HH, Maitre NL, Benninger KL, Hester ME, Slaughter JL. Gabapentin Use for Hospitalized Neonates. Pediatr Neurol 2019; 97:64-70. [PMID: 30922771 PMCID: PMC6635010 DOI: 10.1016/j.pediatrneurol.2019.02.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 02/11/2019] [Accepted: 02/12/2019] [Indexed: 11/18/2022]
Abstract
BACKGROUND Despite some clinician advocacy for the use of gabapentin to treat neonatal irritability of presumed neurological origin, the extent of gabapentin administration to hospitalized neonates is unknown. We aimed to identify trends in gabapentin utilization among infants hospitalized in neonatal intensive care units (NICUs) across the United States and to evaluate the associations between clinical diagnoses and gabapentin treatment. METHODS We analyzed neonates admitted to the NICU using the Pediatric Health Information System (2005 to 2016) to measure treatment timing, duration, and frequency. We used modified Poisson regression with a robust between-cluster variance estimator to calculate a probability (adjusted relative risk) for gabapentin administration. RESULTS Of 278,403 neonates, 374 were administered gabapentin (0.13%). The median treatment duration was 16 days (25th to 75th percentile: 8; 40). Gabapentin use increased from 0% in 2005 to 0.39% in 2016. Treatment was prescribed to neonates at 31 of 48 studied hospitals; 73% of total treated infants localized to five neonatal intensive care units. Term (0.16%) and ≤28 weeks' gestation preterm infants (0.22%) were most likely to receive gabapentin. Varying by gestational age, a diagnosis of chromosomal abnormalities, severe bronchopulmonary dysplasia, hemorrhagic stroke, and neonatal abstinence syndrome were associated with higher treatment with gabapentin. The majority (88.8%) of treated infants did not have a seizure diagnosis. CONCLUSION Gabapentin use in NICU in the United States increased in recent years and varies markedly between institutions. Term infants, ≤28 weeks' gestation preterm infants, and neonates with chronic genetic, neurological, and gastrointestinal diagnoses were more likely to receive gabapentin.
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Affiliation(s)
- Hibo H Abdi
- Center for Perinatal Research, Nationwide Children's Hospital, Columbus, Ohio
| | - Nathalie L Maitre
- Center for Perinatal Research, Nationwide Children's Hospital, Columbus, Ohio; Department of Pediatrics, The Ohio State University, Columbus, Ohio
| | - Kristen L Benninger
- Center for Perinatal Research, Nationwide Children's Hospital, Columbus, Ohio; Department of Pediatrics, The Ohio State University, Columbus, Ohio
| | - Mark E Hester
- Center for Perinatal Research, Nationwide Children's Hospital, Columbus, Ohio
| | - Jonathan L Slaughter
- Center for Perinatal Research, Nationwide Children's Hospital, Columbus, Ohio; Department of Pediatrics, The Ohio State University, Columbus, Ohio.
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12
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Current Overview of Neonatal Convulsions. MEDICAL BULLETIN OF SISLI ETFAL HOSPITAL 2019; 53:1-6. [PMID: 33536818 PMCID: PMC7847733 DOI: 10.14744/semb.2018.22844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 12/06/2018] [Indexed: 11/30/2022]
Abstract
Neonatal convulsions are one of the most common emergency neurological events in the early period after birth. The frequency has been reported to be 1.5 to 3 in 1000 live births. It has been established that the convulsion threshold is lower in infants due to immature neonatal neurons and differences in neurotransmitters. Hypoxic ischemic encephalopathy is the most common etiology in neonatal convulsions. Other causes vary, and may be related to the level of development of the country. Convulsions are classified into 4 different types according to the clinical findings. The most common is the subtle (undefined) type of seizure; the other types are defined as clonic, tonic, and myoclonic seizures. Non-epileptic paroxysmal movements frequently seen in the neonatal period, should not be confused with seizures. The most common non-epileptic paroxysmal movements are jitteriness, benign neonatal sleep myoclonus, and hyperekplexia. A newborn that experiences convulsions should be hospitalized and monitored with continuous video electroencephalogram, if possible. If an initial rapid evaluation detects an acute metabolic disorder, treatment is provided, and, if warranted, it will be followed by a plan for further treatment with anticonvulsant drugs. Phenobarbital is still currently recommended as first-line therapy, though there are studies of other anticonvulsant drugs. Levetiracetam and phenytoin are commonly used as second-step anticonvulsant drugs. The aim of treatment should be not only to stop acute symptomatic seizures, but also to reduce the risk of brain damage and to minimize the possible negative effects of epilepsy and neurological deficits.
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13
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Huizenga MN, Sepulveda-Rodriguez A, Forcelli PA. Preclinical safety and efficacy of cannabidivarin for early life seizures. Neuropharmacology 2019; 148:189-198. [PMID: 30633929 DOI: 10.1016/j.neuropharm.2019.01.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Revised: 11/26/2018] [Accepted: 01/02/2019] [Indexed: 01/25/2023]
Abstract
A significant proportion of neonatal and childhood seizures are poorly controlled by existing anti-seizure drugs (ASDs), likely due to prominent differences in ionic homeostasis and network connectivity between the immature and mature brain. In addition to the poor efficacy of current ASDs, many induce apoptosis, impair synaptic development, and produce behavioral deficits when given during early postnatal development. There is growing interest in new targets, such as cannabidiol (CBD) and its propyl analog cannabidivarin (CBDV) for early life indications. While CBD was recently approved for treatment of refractory childhood epilepsies, little is known about the efficacy or safety of CBDV. Here, we addressed this gap through a systematic evaluation of CBDV against multiple seizure models in postnatal day (P) 10 and 20 animals. We also evaluated the impact of CBDV on acute neurotoxicity in immature rats. CBDV (50-200 mg/kg) displayed an age and model-specific profile of anticonvulsant action. In P10 rats, CBDV suppressed seizures only in the pentylenetetrazole model. In P20 rats, CBDV suppressed seizures in the pentylenetetrazole, DMCM, and maximal electroshock models. Between P10 and P20, we identified significant increases in mRNA expression of TRPV1 in multiple brain regions; when CBDV was tested in P20 TRPV1 knockout mice, anticonvulsant effects were attenuated. Finally, CBDV treatment generally avoided induction of neuronal degeneration in immature rats. Together, the efficacy and safety profile of CBDV suggest it may have therapeutic value for early life seizures.
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Affiliation(s)
- Megan N Huizenga
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC, United States
| | - Alberto Sepulveda-Rodriguez
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC, United States; Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, United States
| | - Patrick A Forcelli
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC, United States; Department of Neuroscience, Georgetown University, Washington, DC, United States; Interdisciplinary Program in Neuroscience, Georgetown University, Washington, DC, United States.
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14
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Bisen S, Simakova MN, Dopico AM, Bukiya AN. Large conductance voltage- and calcium-gated potassium channels (BK) in cerebral artery myocytes of perinatal fetal primates share several major characteristics with the adult phenotype. PLoS One 2018; 13:e0203199. [PMID: 30212531 PMCID: PMC6136719 DOI: 10.1371/journal.pone.0203199] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 06/19/2018] [Indexed: 12/30/2022] Open
Abstract
Large conductance voltage- and calcium-gated channels (BK) control fundamental processes, including smooth muscle contractility and artery diameter. We used a baboon (Papio spp) model of pregnancy that is similar to that of humans to characterize BK channels in the middle cerebral artery and its branches in near-term (165 dGa) primate fetuses and corresponding pregnant mothers. In cell-attached patches (K+pipette = 135 mM) on freshly isolated fetal cerebral artery myocytes, BK currents were identified by large conductance, and voltage- and paxilline-sensitive effects. Their calcium sensitivity was confirmed by a lower Vhalf (transmembrane voltage needed to reach half-maximal current) in inside-out patches at 30 versus 3 μM [Ca2+]free. Immunostaining against the BK channel-forming alpha subunit revealed qualitatively similar levels of BK alpha protein-corresponding fluorescence in fetal and maternal myocytes. Fetal and maternal BK currents recorded at 3 μM [Ca2+]free from excised membrane patches had similar unitary current amplitude, and Vhalf. However, subtle differences between fetal and maternal BK channel phenotypes were detected in macroscopic current activation kinetics. To assess BK function at the organ level, fetal and maternal artery branches were pressurized in vitro at 30 mmHg and probed with the selective BK channel blocker paxilline (1 μM). The degree of paxilline-induced constriction was similar in fetal and maternal arteries, yet the constriction of maternal arteries was achieved sooner. In conclusion, we present a first identification and characterization of fetal cerebral artery BK channels in myocytes from primates. Although differences in BK channels between fetal and maternal arteries exist, the similarities reported herein advance the idea that vascular myocyte BK channels are functional near-term, and thus may serve as pharmacological targets during the perinatal-neonatal period.
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Affiliation(s)
- Shivantika Bisen
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Maria N. Simakova
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Alex M. Dopico
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
| | - Anna N. Bukiya
- Department of Pharmacology, University of Tennessee Health Science Center, Memphis, Tennessee, United States of America
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15
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Quinlan SMM, Rodriguez-Alvarez N, Molloy EJ, Madden SF, Boylan GB, Henshall DC, Jimenez-Mateos EM. Complex spectrum of phenobarbital effects in a mouse model of neonatal hypoxia-induced seizures. Sci Rep 2018; 8:9986. [PMID: 29968748 PMCID: PMC6030182 DOI: 10.1038/s41598-018-28044-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 06/11/2018] [Indexed: 11/09/2022] Open
Abstract
Seizures in neonates, mainly caused by hypoxic-ischemic encephalopathy, are thought to be harmful to the brain. Phenobarbital remains the first line drug therapy for the treatment of suspected neonatal seizures but concerns remain with efficacy and safety. Here we explored the short- and long-term outcomes of phenobarbital treatment in a mouse model of hypoxia-induced neonatal seizures. Seizures were induced in P7 mice by exposure to 5% O2 for 15 minutes. Immediately after hypoxia, pups received a single dose of phenobarbital (25 mg.kg-1) or saline. We observed that after administration of phenobarbital seizure burden and number of seizures were reduced compared to the hypoxic period; however, PhB did not suppress acute histopathology. Behavioural analysis of mice at 5 weeks of age previously subjected to hypoxia-seizures revealed an increase in anxiety-like behaviour and impaired memory function compared to control littermates, and these effects were not normalized by phenobarbital. In a seizure susceptibility test, pups previously exposed to hypoxia, with or without phenobarbital, developed longer and more severe seizures in response to kainic acid injection compared to control mice. Unexpectedly, mice treated with phenobarbital developed less hippocampal damage after kainic acid than untreated counterparts. The present study suggests phenobarbital treatment in immature mice does not improve the long lasting functional deficits induces by hypoxia-induced seizures but, unexpectedly, may reduce neuronal death caused by exposure to a second seizure event in later life.
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Affiliation(s)
- Sean M M Quinlan
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123, St Stephen Green, Dublin, 2, Dublin, Ireland
| | - Natalia Rodriguez-Alvarez
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123, St Stephen Green, Dublin, 2, Dublin, Ireland
| | - Eleanor J Molloy
- Paediatrics, Academic Centre, Tallaght Hospital, Trinity College, The University of Dublin, Dublin, Ireland.,Neonatology, Coombe Women and Infants' University Hospital, Dublin, Ireland.,Neonatology, Our Lady's Children's Hospital Crumlin, Dublin, Ireland
| | - Stephen F Madden
- Data Science Centre, Beaux Lane House, Royal College of Surgeons in Ireland, Dublin, 2, Ireland
| | - Geraldine B Boylan
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork, Ireland.,Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123, St Stephen Green, Dublin, 2, Dublin, Ireland.,Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork, Ireland
| | - Eva M Jimenez-Mateos
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123, St Stephen Green, Dublin, 2, Dublin, Ireland.
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16
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Kirischuk S, Sinning A, Blanquie O, Yang JW, Luhmann HJ, Kilb W. Modulation of Neocortical Development by Early Neuronal Activity: Physiology and Pathophysiology. Front Cell Neurosci 2017; 11:379. [PMID: 29238291 PMCID: PMC5712676 DOI: 10.3389/fncel.2017.00379] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Accepted: 11/13/2017] [Indexed: 12/23/2022] Open
Abstract
Animal and human studies revealed that patterned neuronal activity is an inherent feature of developing nervous systems. This review summarizes our current knowledge about the mechanisms generating early electrical activity patterns and their impact on structural and functional development of the cerebral cortex. All neocortical areas display distinct spontaneous and sensory-driven neuronal activity patterns already at early phases of development. At embryonic stages, intermittent spontaneous activity is synchronized within small neuronal networks, becoming more complex with further development. This transition is accompanied by a gradual shift from electrical to chemical synaptic transmission, with a particular role of non-synaptic tonic currents before the onset of phasic synaptic activity. In this review article we first describe functional impacts of classical neurotransmitters (GABA, glutamate) and modulatory systems (e.g., acetylcholine, ACh) on early neuronal activities in the neocortex with special emphasis on electrical synapses, nonsynaptic and synaptic currents. Early neuronal activity influences probably all developmental processes and is crucial for the proper formation of neuronal circuits. In the second part of our review, we illustrate how specific activity patterns might interfere with distinct neurodevelopmental processes like proliferation, migration, axonal and dendritic sprouting, synapse formation and neurotransmitter specification. Finally, we present evidence that transient alterations in neuronal activity during restricted perinatal periods can lead to persistent changes in functional connectivity and therefore might underlie the manifestation of neurological and neuropsychiatric diseases.
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Affiliation(s)
- Sergei Kirischuk
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Anne Sinning
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Oriane Blanquie
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Jenq-Wei Yang
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Heiko J Luhmann
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Werner Kilb
- Institute of Physiology, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
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17
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Pisani F, Pavlidis E, Facini C, La Morgia C, Fusco C, Cantalupo G. A 15-year epileptogenic period after perinatal brain injury. FUNCTIONAL NEUROLOGY 2017; 32:49-53. [PMID: 28380324 DOI: 10.11138/fneur/2017.32.1.049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Seizures are a frequent acute neurological event in the neonatal period. Up to 12 to 18% of all seizures in newborns are due to perinatal stroke and up to 39% of affected children can then develop epilepsy in childhood. We report the case of a young patient who presented stroke-related seizures in the neonatal period and then developed focal symptomatic epilepsy at 15 years of age, and in whom the epileptic focus was found to co-localize with the site of his ischemic brain lesion. Such a prolonged silent period before onset of remote symptomatic epilepsy has not previously been reported. This case suggests that newborns with seizures due to a neonatal stroke are at higher risk of epilepsy and that the epileptogenic process in these subjects can last longer than a decade.
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18
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Rodriguez-Alvarez N, Jimenez-Mateos EM, Engel T, Quinlan S, Reschke CR, Conroy RM, Bhattacharya A, Boylan GB, Henshall DC. Effects of P2X7 receptor antagonists on hypoxia-induced neonatal seizures in mice. Neuropharmacology 2017; 116:351-363. [PMID: 28082183 DOI: 10.1016/j.neuropharm.2017.01.005] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Revised: 12/12/2016] [Accepted: 01/08/2017] [Indexed: 12/28/2022]
Abstract
Neonatal seizures are a common consequence of hypoxic/ischemic encephalopathy (HIE). Phenobarbital remains the frontline treatment for neonatal seizures but is often ineffective. The P2X7 receptor (P2X7R) is a cell surface-expressed ionotropic receptor activated by high amounts of ATP which may be released during seizures or as a consequence of tissue injury. Here, we explored the role of the P2X7R in a mouse model of neonatal seizures induced by hypoxia. Exposure of postnatal day 7 (P7) mouse pups to global hypoxia (5% O2 for 15 min) produced electrographically-defined seizures with behavioural correlates that persisted after restitution of normoxia. Expression of the P2X7R showed age-dependent increases in the hippocampus and neocortex of developing mice and was present in human neonatal brain. P2X7R transcript and protein levels were increased 24 h after neonatal hypoxia-induced seizures in mouse pups. EEG recordings in pups determined that injection of the P2X7R antagonist A-438079 (25 mg/kg-1, intraperitoneal) reduced electrographic seizure number, EEG power and spiking during hypoxia. A-438079 did not reduce post-hypoxia seizures. Caspase-1 processing and molecular markers of inflammation and microglia were reduced in A438079-treated mice. Electrographic seizure-suppressive effects were also observed with a second P2X7R antagonist, JNJ-47965567, in the same model. The present study shows hypoxia-induced seizures alter expression of purinergic and neuroinflammatory signalling components and suggest potential applications but also limitations of the P2X7R as a target for the treatment of HIE and other causes of neonatal seizures.
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Affiliation(s)
- Natalia Rodriguez-Alvarez
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - Eva M Jimenez-Mateos
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - Tobias Engel
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - Sean Quinlan
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - Cristina R Reschke
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland
| | - Ronán M Conroy
- Division of Population Health Sciences, Royal College of Surgeons in Ireland, Dublin, Ireland
| | | | - Geraldine B Boylan
- Irish Centre for Fetal and Neonatal Translational Research (INFANT) Cork, Ireland
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, 123 St. Stephen's Green, Dublin 2, Ireland; Irish Centre for Fetal and Neonatal Translational Research (INFANT) Cork, Ireland.
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19
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Harris ML, Malloy KM, Lawson SN, Rose RS, Buss WF, Mietzsch U. Standardized Treatment of Neonatal Status Epilepticus Improves Outcome. J Child Neurol 2016; 31:1546-1554. [PMID: 27581850 DOI: 10.1177/0883073816664670] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 05/10/2016] [Accepted: 07/04/2016] [Indexed: 11/16/2022]
Abstract
We aimed to decrease practice variation in treatment of neonatal status epilepticus by implementing a standardized protocol. Our primary goal was to achieve 80% adherence to the algorithm within 12 months. Secondary outcome measures included serum phenobarbital concentrations, number of patients progressing from seizures to status epilepticus, and length of hospital stay. Data collection occurred for 6 months prior and 12 months following protocol implementation. Adherence of 80% within 12 months was partially achieved in patients diagnosed in our hospital; in pretreated patients, adherence was not achieved. Maximum phenobarbital concentrations were decreased (56.8 vs 41.0 µg/mL), fewer patients progressed from seizures to status epilepticus (46% vs 36%), and hospital length of stay decreased by 9.7 days in survivors. In conclusion, standardized, protocol-driven treatment of neonatal status epilepticus improves consistency and short-term outcome.
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Affiliation(s)
- Mandy L Harris
- Department of Neurology, Division of Child Neurology, Indiana University, School of Medicine, Indianapolis, IN, USA
| | - Katherine M Malloy
- Department of Clinical Pharmacy, Riley Hospital for Children at Indiana University Health, Indianapolis, IN, USA
| | - Sheena N Lawson
- Neonatal Intensive Care Unit, Riley Hospital for Children at Indiana University Health, Indianapolis, IN, USA
| | - Rebecca S Rose
- Department of Pediatrics, Division of Neonatology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - William F Buss
- Department of Clinical Pharmacy, Riley Hospital for Children at Indiana University Health, Indianapolis, IN, USA
| | - Ulrike Mietzsch
- Department of Pediatrics, Division of Neonatology, Indiana University School of Medicine, Indianapolis, IN, USA
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20
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Harsono M, Pourcyrous M, Jolly EJ, de Jongh Curry A, Fedinec AL, Liu J, Basuroy S, Zhuang D, Leffler CW, Parfenova H. Selective head cooling during neonatal seizures prevents postictal cerebral vascular dysfunction without reducing epileptiform activity. Am J Physiol Heart Circ Physiol 2016; 311:H1202-H1213. [PMID: 27591217 DOI: 10.1152/ajpheart.00227.2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 08/22/2016] [Indexed: 01/12/2023]
Abstract
Epileptic seizures in neonates cause cerebrovascular injury and impairment of cerebral blood flow (CBF) regulation. In the bicuculline model of seizures in newborn pigs, we tested the hypothesis that selective head cooling prevents deleterious effects of seizures on cerebral vascular functions. Preventive or therapeutic ictal head cooling was achieved by placing two head ice packs during the preictal and/or ictal states, respectively, for the ∼2-h period of seizures. Head cooling lowered the brain and core temperatures to 25.6 ± 0.3 and 33.5 ± 0.1°C, respectively. Head cooling had no anticonvulsant effects, as it did not affect the bicuculline-evoked electroencephalogram parameters, including amplitude, duration, spectral power, and spike frequency distribution. Acute and long-term cerebral vascular effects of seizures in the normothermic and head-cooled groups were tested during the immediate (2-4 h) and delayed (48 h) postictal periods. Seizure-induced cerebral vascular injury during the immediate postictal period was detected as terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling-positive staining of cerebral arterioles and a surge of brain-derived circulating endothelial cells in peripheral blood in the normothermic group, but not in the head-cooled groups. During the delayed postictal period, endothelium-dependent cerebral vasodilator responses were greatly reduced in the normothermic group, indicating impaired CBF regulation. Preventive or therapeutic ictal head cooling mitigated the endothelial injury and greatly reduced loss of postictal cerebral vasodilator functions. Overall, head cooling during seizures is a clinically relevant approach to protecting the neonatal brain by preventing cerebrovascular injury and the loss of the endothelium-dependent control of CBF without reducing epileptiform activity.
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Affiliation(s)
- Mimily Harsono
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Massroor Pourcyrous
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Elliott J Jolly
- Department of Biomedical Engineering, University of Memphis, Memphis, Tennessee
| | - Amy de Jongh Curry
- Department of Biomedical Engineering, University of Memphis, Memphis, Tennessee
| | - Alexander L Fedinec
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Jianxiong Liu
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Shyamali Basuroy
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Daming Zhuang
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Charles W Leffler
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
| | - Helena Parfenova
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee; and
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21
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Donovan MD, Boylan GB, Murray DM, Cryan JF, Griffin BT. Treating disorders of the neonatal central nervous system: pharmacokinetic and pharmacodynamic considerations with a focus on antiepileptics. Br J Clin Pharmacol 2015; 81:62-77. [PMID: 26302437 DOI: 10.1111/bcp.12753] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 08/05/2015] [Accepted: 08/13/2015] [Indexed: 12/31/2022] Open
Abstract
A major consideration in the treatment of neonatal disorders is that the selected drug, dose and dosage frequency is safe, effective and appropriate for the intended patient population. Thus, a thorough knowledge of the pharmacokinetics and pharmacodynamics of the chosen drug within the patient population is essential. In paediatric and neonatal populations two additional challenges can often complicate drug treatment - the inherently greater physiological variability, and a lack of robust clinical evidence of therapeutic range. There has traditionally been an overreliance in paediatric medicine on extrapolating doses from adult values by adjusting for bodyweight or body surface area, but many other sources of variability exist which complicate the choice of dose in neonates. The lack of reliable drug dosage data in neonates has been highlighted by regulatory authorities, as only ~50% of the most commonly used paediatric medicines have been examined in a paediatric population. Moreover, there is a paucity of information on the pharmacokinetic parameters which affect drug concentrations in different body tissues, and pharmacodynamic responses to drugs in the neonate. Thus, in the present review, we draw attention to the main pharmacokinetic factors that influence the unbound brain concentration of neuroactive drugs. Moreover, the pharmacodynamic differences between neonates and adults that affect the activity of centrally-acting therapeutic agents are briefly examined, with a particular emphasis on antiepileptic drugs.
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Affiliation(s)
- Maria D Donovan
- Pharmacodelivery Group, School of Pharmacy, University College Cork, Cork, Ireland.,Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland
| | - Geraldine B Boylan
- Department of Paediatrics and Child Health, University College Cork, Cork, Ireland.,Irish Centre for Fetal and Neonatal Translational Research, University College Cork and Cork University Maternity Hospital, Cork, Ireland
| | - Deirdre M Murray
- Department of Paediatrics and Child Health, University College Cork, Cork, Ireland
| | - John F Cryan
- Department of Anatomy and Neuroscience, University College Cork, Cork, Ireland.,Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Brendan T Griffin
- Pharmacodelivery Group, School of Pharmacy, University College Cork, Cork, Ireland
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22
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Rodriguez-Alvarez N, Jimenez-Mateos EM, Dunleavy M, Waddington JL, Boylan GB, Henshall DC. Effects of hypoxia-induced neonatal seizures on acute hippocampal injury and later-life seizure susceptibility and anxiety-related behavior in mice. Neurobiol Dis 2015; 83:100-14. [PMID: 26341542 DOI: 10.1016/j.nbd.2015.08.023] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 08/06/2015] [Accepted: 08/21/2015] [Indexed: 12/30/2022] Open
Abstract
Seizures are common during the neonatal period, often due to hypoxic-ischemic encephalopathy and may contribute to acute brain injury and the subsequent development of cognitive deficits and childhood epilepsy. Here we explored short- and long-term consequences of neonatal hypoxia-induced seizures in 7 day old C57BL/6J mice. Seizure activity, molecular markers of hypoxia and histological injury were investigated acutely after hypoxia and response to chemoconvulsants and animal behaviour was explored at adulthood. Hypoxia was induced by exposing pups to 5% oxygen for 15 min (global hypoxia). Electrographically defined seizures with behavioral correlates occurred in 95% of these animals and seizures persisted for many minutes after restitution of normoxia. There was minimal morbidity or mortality. Pre- or post-hypoxia injection of phenobarbital (50mg/kg) had limited efficacy at suppressing seizures. The hippocampus from neonatal hypoxia-seizure mice displayed increased expression of vascular endothelial growth factor and the immediate early gene c-fos, minimal histological evidence of cell injury and activation of caspase-3 in scattered neurons. Behavioral analysis of mice five weeks after hypoxia-induced seizures detected novel anxiety-related and other behaviors, while performance in a spatial memory test was similar to controls. Seizure threshold tests with kainic acid at six weeks revealed that mice previously subject to neonatal hypoxia-induced seizures developed earlier, more frequent and longer-duration seizures. This study defines a set of electro-clinical, molecular, pharmacological and behavioral consequences of hypoxia-induced seizures that indicate short- and long-term deleterious outcomes and may be a useful model to investigate the pathophysiology and treatment of neonatal seizures in humans.
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Affiliation(s)
| | - Eva M Jimenez-Mateos
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Mark Dunleavy
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - John L Waddington
- Department of Molecular and Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Geraldine B Boylan
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork, Ireland
| | - David C Henshall
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland; Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork, Ireland.
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Liu J, Fedinec AL, Leffler CW, Parfenova H. Enteral supplements of a carbon monoxide donor CORM-A1 protect against cerebrovascular dysfunction caused by neonatal seizures. J Cereb Blood Flow Metab 2015; 35:193-9. [PMID: 25370858 PMCID: PMC4426744 DOI: 10.1038/jcbfm.2014.196] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Revised: 10/02/2014] [Accepted: 10/15/2014] [Indexed: 11/09/2022]
Abstract
Cerebral blood flow dysregulation caused by oxidative stress contributes to adverse neurologic outcome of seizures. A carbon monoxide (CO) donor CORM-A1 has antioxidant and cytoprotective properties. We investigated whether enteral supplements of CORM-A1 can improve cerebrovascular outcome of bicuculline-induced seizures in newborn piglets. CORM-A1 (2 mg/kg) was given to piglets via an oral gastric tube 10 minutes before or 20 minutes after seizure onset. Enteral CORM-A1 elevated CO in periarachnoid cerebrospinal fluid and produced a dilation of pial arterioles. Postictal cerebral vascular responses to endothelium-, astrocyte-, and vascular smooth muscle-dependent vasodilators were tested 48 hours after seizures by intravital microscopy. The postictal responses of pial arterioles to bradykinin, glutamate, the AMPA receptor agonist quisqualic acid, ADP, and heme were greatly reduced, suggesting that seizures cause injury to endothelial and astrocyte components of the neurovascular unit. In contrast, in the two groups of piglets receiving enteral CORM-A1, the postictal cerebral vascular responsiveness to these dilators was improved. Overall, enteral supplements of CORM-A1 before or during seizures offer a novel effective therapeutic option to deliver cytoprotective mediator CO to the brain, reduce injury to endothelial and astrocyte components of cerebral blood flow regulation and to improve the cerebrovascular outcome of neonatal seizures.
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Affiliation(s)
- Jianxiong Liu
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Alexander L Fedinec
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Charles W Leffler
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Helena Parfenova
- Department of Physiology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
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TALEBIAN A, JAHANGIRI M, RABIEE M, MASOUDI ALAVI N, AKBARI H, SADAT Z. The Etiology and Clinical Evaluations of Neonatal Seizures in Kashan, IRAN. IRANIAN JOURNAL OF CHILD NEUROLOGY 2015; 9. [PMID: 26221160 PMCID: PMC4515338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Detection of seizure, its etiology, and clinical types is important for guiding therapy. This study was designed to evaluate the etiology and clinical evaluations of neonatal seizures in Kashan, Iran. MATERIALS AND METHODS The data of 100 hospitalized neonates with a complaint of seizures in Kashan City, from January 2006 to January 2011 were evaluated. The pediatric neurologist made the final diagnosis. The gestational age, neonate admission age, type of delivery, and laboratory and radiological investigations were reviewed from the medical records. The relation of seizure etiology and other variables were compared using the Chi-square test. All the statistical analyses were performed using SPSS (ver 11.5). RESULTS A total of 100 neonates were hospitalized with a diagnosis of seizures. The overall incidence rate of seizures was 2.6 per 1,000 live births. A total of 59% of seizures happened in the first three days of life. The etiologies of seizures were hypoxicischemic encephalopathy (HIE) (36%), hyponatremia (12%), hypoglycemia (11%), intracranial hemorrhage (11%), infections (10%), hypocalcemia (8%), metabolic disorders (7%), the structural anomalies (5%), and hypomagnesaemia (4%). In 23% of neonates, no specific etiology was found and 23% had multiple etiologies. In 45% of neonates, the EEG was not recorded. The type of the seizures were focal-clonic (26%), tonic (25%), multifocal clonic (34%), subtle (11%), and myoclonic (4%). The types of the seizure were unrelated to the paraclinical findings. CONCLUSION Neonatal seizures are common and HIE was the main cause of seizures in this study. The clinical evaluation of neonatal seizures needs improvement.
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Affiliation(s)
- Ahmad TALEBIAN
- Pediatric Department, Kashan University of Medical Sciences, Kashan, Iran
| | - Mohammad JAHANGIRI
- Pediatric Department, Kashan University of Medical Sciences, Kashan, Iran
| | - Mahin RABIEE
- Pediatric Department, Kashan University of Medical Sciences, Kashan, Iran
| | - Negin MASOUDI ALAVI
- Trauma Nursing Research Center, Medical Surgical Department, Kashan University of Medical Sciences, Kashan, Iran ,Corresponding Author: Masoudi Alavi N. MD ,Ghotb Ravandi Highway, Kashan University of Medical Sciences, Kashan/IRAN, Tel: +98 3155540021 ,
| | - Hossein AKBARI
- Department of Statistics, Kashan University of Medical Sciences, Kashan, Iran
| | - Zohreh SADAT
- Trauma Nursing Research Center, Midwifery Department,Kashan University of Medical Sciences, Kashan, Iran
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Pisani F, Facini C, Pavlidis E, Spagnoli C, Boylan G. Epilepsy after neonatal seizures: literature review. Eur J Paediatr Neurol 2015; 19:6-14. [PMID: 25455712 DOI: 10.1016/j.ejpn.2014.10.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Revised: 09/12/2014] [Accepted: 10/05/2014] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Acute neonatal seizures are the most frequent neurological complication in the neonatal intensive care units and the seizing newborns have an increased risk of long-term morbidity. However, the relationship between neonatal seizures and the development of epilepsy later in life is still unclear. METHODS We performed a literature review using the search terms "neonatal seizures AND outcome", "neonatal seizures AND epilepsy", "neonatal seizures AND post-neonatal epilepsy", including secondary sources of data such as reference lists of articles reviewed. From the studies in which data were available, the incidence of epilepsy was calculated by dividing the number of all subjects who developed epilepsy in the different studies considered with the number of all newborns enrolled to the studies less the number of patients lost at follow-up. RESULTS We found 44 studies published between 1954 and 2013, of which 4 were population-based studies and the remaining were hospital-based case series. The overall population evaluated was 4538 newborns and 17.9% developed post-neonatal epilepsy, with an onset within the first year of life in 68.5% of the patients. In 80.7%, epilepsy was associated with other neurological impairments. CONCLUSION Estimates on epilepsy after neonatal seizures vary widely depending on selection criteria and length of the follow-up. However, it represents a common outcome of these newborns, especially in those with severe brain injury and additional neurodevelopmental disabilities.
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Affiliation(s)
- Francesco Pisani
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
| | - Carlotta Facini
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
| | - Elena Pavlidis
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
| | - Carlotta Spagnoli
- Child Neuropsychiatry Unit, Neuroscience Department, University of Parma, Via Gramsci 14, 43126 Parma, Italy.
| | - Geraldine Boylan
- Department of Paediatrics & Child Health, University College Cork, Ireland.
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Akman O, Moshé SL, Galanopoulou AS. Sex-specific consequences of early life seizures. Neurobiol Dis 2014; 72 Pt B:153-66. [PMID: 24874547 DOI: 10.1016/j.nbd.2014.05.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/07/2014] [Accepted: 05/17/2014] [Indexed: 12/29/2022] Open
Abstract
Seizures are very common in the early periods of life and are often associated with poor neurologic outcome in humans. Animal studies have provided evidence that early life seizures may disrupt neuronal differentiation and connectivity, signaling pathways, and the function of various neuronal networks. There is growing experimental evidence that many signaling pathways, like GABAA receptor signaling, the cellular physiology and differentiation, or the functional maturation of certain brain regions, including those involved in seizure control, mature differently in males and females. However, most experimental studies of early life seizures have not directly investigated the importance of sex on the consequences of early life seizures. The sexual dimorphism of the developing brain raises the question that early seizures could have distinct effects in immature females and males that are subjected to seizures. We will first discuss the evidence for sex-specific features of the developing brain that could be involved in modifying the susceptibility and consequences of early life seizures. We will then review how sex-related biological factors could modify the age-specific consequences of induced seizures in the immature animals. These include signaling pathways (e.g., GABAA receptors), steroid hormones, growth factors. Overall, there are very few studies that have specifically addressed seizure outcomes in developing animals as a function of sex. The available literature indicates that a variety of outcomes (histopathological, behavioral, molecular, epileptogenesis) may be affected in a sex-, age-, region-specific manner after seizures during development. Obtaining a better understanding for the gender-related mechanisms underlying epileptogenesis and seizure comorbidities will be necessary to develop better gender and age appropriate therapies.
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Affiliation(s)
- Ozlem Akman
- Department of Physiology, Faculty of Medicine, Istanbul Bilim University, 34394 Istanbul, Turkey.
| | - Solomon L Moshé
- Saul R. Korey Department of Neurology, Laboratory of Developmental Epilepsy, Montefiore Epilepsy Management Center, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA; Department of Pediatrics, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA
| | - Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Laboratory of Developmental Epilepsy, Montefiore Epilepsy Management Center, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA; Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY, 10461, USA
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Mesuret G, Engel T, Hessel EV, Sanz-Rodriguez A, Jimenez-Pacheco A, Miras-Portugal MT, Diaz-Hernandez M, Henshall DC. P2X7 receptor inhibition interrupts the progression of seizures in immature rats and reduces hippocampal damage. CNS Neurosci Ther 2014; 20:556-64. [PMID: 24750893 DOI: 10.1111/cns.12272] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Revised: 03/18/2014] [Accepted: 03/23/2014] [Indexed: 12/15/2022] Open
Abstract
AIMS Early-life seizures, particularly when prolonged, may be harmful to the brain. Current pharmacotherapy is often ineffective; therefore, novel neuro- and/or glio-transmitter systems should be explored for targeting. The P2X7 receptor is a cation-permeable channel with trophic and excitability effects on neurons and glia which is activated by high amounts of ATP that may be released in the setting of injury after severe seizures. Here, we tested the effects of A-438079, a potent and selective P2X7 receptor antagonist in a lesional model of early-life status epilepticus. METHODS Seizures were induced by intra-amygdala kainic acid in 10-day-old rat pups. Electrographic seizure severity, changes to P2X7 receptor expression, inflammatory responses and histological effects were evaluated. RESULTS Seizures induced by intra-amygdala kainic acid increased levels of P2X7 receptor protein and interleukin-1β and caused significant cell death within the ipsilateral hippocampus. A-438079 rapidly reached the brain following systemic injection in P10 rats. Intraperitoneal injection of A-438079 (5 and 15 mg/kg) 60 min after triggering seizures reduced seizure severity and neuronal death within the hippocampus. A-438079 had superior neuroprotective effects compared with an equally seizure-suppressive dose of phenobarbital (25 mg/kg). CONCLUSIONS These results suggest P2X7 receptor antagonists may be suitable as frontline or adjunctive treatments of pediatric status epilepticus or other early-life seizures, particularly when associated with brain damage.
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Affiliation(s)
- Guillaume Mesuret
- Department of Physiology & Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
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Genotype-phenotype correlations in neonatal epilepsies caused by mutations in the voltage sensor of K(v)7.2 potassium channel subunits. Proc Natl Acad Sci U S A 2013; 110:4386-91. [PMID: 23440208 DOI: 10.1073/pnas.1216867110] [Citation(s) in RCA: 138] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Mutations in the K(V)7.2 gene encoding for voltage-dependent K(+) channel subunits cause neonatal epilepsies with wide phenotypic heterogeneity. Two mutations affecting the same positively charged residue in the S4 domain of K(V)7.2 have been found in children affected with benign familial neonatal seizures (R213W mutation) or with neonatal epileptic encephalopathy with severe pharmacoresistant seizures and neurocognitive delay, suppression-burst pattern at EEG, and distinct neuroradiological features (R213Q mutation). To examine the molecular basis for this strikingly different phenotype, we studied the functional characteristics of mutant channels by using electrophysiological techniques, computational modeling, and homology modeling. Functional studies revealed that, in homomeric or heteromeric configuration with K(V)7.2 and/or K(V)7.3 subunits, both mutations markedly destabilized the open state, causing a dramatic decrease in channel voltage sensitivity. These functional changes were (i) more pronounced for channels incorporating R213Q- than R213W-carrying K(V)7.2 subunits; (ii) proportional to the number of mutant subunits incorporated; and (iii) fully restored by the neuronal K(v)7 activator retigabine. Homology modeling confirmed a critical role for the R213 residue in stabilizing the activated voltage sensor configuration. Modeling experiments in CA1 hippocampal pyramidal cells revealed that both mutations increased cell firing frequency, with the R213Q mutation prompting more dramatic functional changes compared with the R213W mutation. These results suggest that the clinical disease severity may be related to the extent of the mutation-induced functional K(+) channel impairment, and set the preclinical basis for the potential use of K(v)7 openers as a targeted anticonvulsant therapy to improve developmental outcome in neonates with K(V)7.2 encephalopathy.
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