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Hutson T, Pizarro D, Pati S, Iasemidis LD. Predictability and Resetting in a Case of Convulsive Status Epilepticus. Front Neurol 2018; 9:172. [PMID: 29623064 PMCID: PMC5874309 DOI: 10.3389/fneur.2018.00172] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 03/06/2018] [Indexed: 11/13/2022] Open
Abstract
In this case study, we present evidence of resetting of brain dynamics following convulsive status epilepticus (SE) that was treated successfully with antiepileptic medications (AEDs). The measure of effective inflow (EI), a novel measure of network connectivity, was applied to the continuously recorded multichannel intracranial stereoelectroencephalographic (SEEG) signals before, during and after SE. Results from this analysis indicate trends of progressive reduction of EI over hours up to the onset of SE, mainly at sites of the epileptogenic focus with reversal of those trends upon successful treatment of SE by AEDs. The proposed analytical framework is promising for elucidation of the pathology of neuronal network dynamics that could lead to SE, evaluation of the efficacy of SE treatment strategies, as well as the development of biomarkers for susceptibility to SE.
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Affiliation(s)
- Timothy Hutson
- Department of Biomedical Engineering, Louisiana Tech University, Ruston, LA, United States
| | - Diana Pizarro
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Sandipan Pati
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Leon D Iasemidis
- Department of Biomedical Engineering, Louisiana Tech University, Ruston, LA, United States
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Dulin JD, Noreika DM, Coyne PJ. Management of refractory status epilepticus in an actively dying patient. J Pain Palliat Care Pharmacother 2014; 28:243-50. [PMID: 25166773 DOI: 10.3109/15360288.2014.941129] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
No consensus guidelines exist for the treatment of refractory myoclonic status epilepticus or refractory myoclonus in the palliative care setting. Evidence-based guidelines for the general medical population are often neither practical nor applicable at the end of life. Many challenges, including medication availability, route of administration, monitoring, and work-up are all unique to the palliative care setting. Two patients with refractory myoclonus versus refractory myoclonic status epilepticus are described here, illustrating the challenges involved in treatment as well the need for further research for therapy in the palliative care setting.
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Xie Y, Morgan R, Schiff L, Hannah D, Wheless J. A computerized standard protocol order entry for pediatric inpatient acute seizure emergencies reduces time to treatment. J Child Neurol 2014; 29:162-6. [PMID: 23392562 DOI: 10.1177/0883073812474950] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Time to treatment of seizures is critical to efficacy. We performed a quality initiative and evaluated time to treatment of inpatient seizure emergencies with first- and second-line medicines before and after implementation of a computerized, standard treatment protocol. Data from 125 patients revealed that 179 seizure episodes required first-line antiepileptic drugs, and the mean time to treatment was 7.72 minutes. In 87 episodes, patients (49%) received the drugs within 5 minutes. Forty-six episodes required second-line drugs. In 17 (37%), patients received them within 30 minutes (mean 49.48 minutes). After implementation of the protocol, the mean time to treatment with first-line drugs was 3.74 minutes, a reduction of >50% (P < .0001). The mean time to treatment with second-line drugs was 25.05 minutes, a reduction of ∼50% (P < .0001). This effective model for reducing the time to treatment of seizure emergencies may be useful to similar institutions.
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Affiliation(s)
- Yi Xie
- 1University of Tennessee Health Science Center, Memphis, TN, USA
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Sanjoinine A isolated from Semen Zizyphi Spinosi protects against kainic acid-induced convulsions. Arch Pharm Res 2010; 32:1515-23. [PMID: 20091264 DOI: 10.1007/s12272-009-2103-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 08/05/2009] [Accepted: 08/11/2009] [Indexed: 10/20/2022]
Abstract
These experiments were performed to know whether sanjoinine A, a component of the alkaloid fraction of Semen Zizyphi Spinosi, acts as an anti-convulsive agent in the kainic acid (KA)-induced experimental convulsion model and whether these effects are mediated by decreased intracellular calcium. Oral administration of sanjoinine A (4 and 8 mg/kg) increased the survival rate and latency of convulsion onset, and decreased the seizure scores and the weight loss induced by intraperitoneal (i.p.) injection of KA (50 mg/kg) in mice. In addition, sanjoinine A protected against neuronal damage and apoptosis in the hippocampus after KA administration, as analyzed by using immunohistochemistry and TUNEL assay. Sanjoinine A also significantly blocked seizure-form electroencephalogram alterations induced by KA. Moreover, in cultured rat neuronal cells, sanjoinine A inhibited KA-induced cell death, as measured by propidium iodide detection. Sanjoinine A also increased intracellular chloride and inhibited the elevation of intracellular calcium induced by KA. Sanjoinine A, therefore protects against KA-induced convulsions by increasing intracellular chloride and reducing intracellular calcium levels.
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Konieczny PL, Reimer R. 25-year-old woman with new-onset seizures. Mayo Clin Proc 2009; 84:285-8. [PMID: 19252118 PMCID: PMC2664602 DOI: 10.1016/s0025-6196(11)61148-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Peter L. Konieczny
- Resident in Neurology, Mayo School of Graduate Medical Education, Mayo Clinic, Rochester, MN
| | - Ronald Reimer
- Adviser to resident and Consultant in Neurosurgery, Mayo Clinic, Jacksonville, FL
- Individual reprints of this article are not available. Address correspondence to Ronald Reimer, MD, Department of Neurosurgery, Mayo Clinic, 4500 San Pablo Rd, Jacksonville, FL 32224 ()
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Konieczny PL, Reimer R. 25-year-old woman with new-onset seizures. Mayo Clin Proc 2009; 84:285-8. [PMID: 19252118 PMCID: PMC2664602 DOI: 10.4065/84.3.285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Affiliation(s)
- Peter L. Konieczny
- Resident in Neurology, Mayo School of Graduate Medical Education, Mayo Clinic, Rochester, MN
| | - Ronald Reimer
- Adviser to resident and Consultant in Neurosurgery, Mayo Clinic, Jacksonville, FL
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Droney J, Hall E. Status epilepticus in a hospice inpatient setting. J Pain Symptom Manage 2008; 36:97-105. [PMID: 18358684 DOI: 10.1016/j.jpainsymman.2007.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2006] [Revised: 08/06/2007] [Accepted: 08/08/2007] [Indexed: 10/22/2022]
Abstract
Although evidence-based guidelines on the management of status epilepticus in the general population are available, these cannot be readily applied to hospice inpatients. The treatment of status epilepticus in a hospice setting presents many challenges in terms of choice and availability of drugs, route of administration and availability of monitoring facilities. A case report is presented that illustrates the distinct challenges involved in the management of status epilepticus in this setting. Commonly used antiseizure medications are discussed, with emphasis on the potential benefits and drawbacks in a hospice population.
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Affiliation(s)
- Joanne Droney
- Palliative Medicine Department, Royal Marsden Hospital, London, United Kingdom.
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Deficits in phosphorylation of GABA(A) receptors by intimately associated protein kinase C activity underlie compromised synaptic inhibition during status epilepticus. J Neurosci 2008; 28:376-84. [PMID: 18184780 DOI: 10.1523/jneurosci.4346-07.2008] [Citation(s) in RCA: 114] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Status epilepticus (SE) is a progressive and often lethal human disorder characterized by continuous or rapidly repeating seizures. Of major significance in the pathology of SE are deficits in the functional expression of GABA(A) receptors (GABA(A)Rs), the major sites of fast synaptic inhibition in the brain. We demonstrate that SE selectively decreases the phosphorylation of GABA(A)Rs on serine residues 408/9 (S408/9) in the beta3 subunit by intimately associated protein kinase C isoforms. Dephosphorylation of S408/9 unmasks a basic patch-binding motif for the clathrin adaptor AP2, enhancing the endocytosis of selected GABA(A)R subtypes from the plasma membrane during SE. In agreement with this, enhancing S408/9 phosphorylation or selectively blocking the binding of the beta3 subunit to AP2 increased GABA(A)R cell surface expression levels and restored the efficacy of synaptic inhibition in SE. Thus, enhancing phosphorylation of GABA(A)Rs or selectively blocking their interaction with AP2 may provide novel therapeutic strategies to ameliorate SE.
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Park HG, Yoon SY, Choi JY, Lee GS, Choi JH, Shin CY, Son KH, Lee YS, Kim WK, Ryu JH, Ko KH, Cheong JH. Anticonvulsant effect of wogonin isolated from Scutellaria baicalensis. Eur J Pharmacol 2007; 574:112-9. [PMID: 17692312 DOI: 10.1016/j.ejphar.2007.07.011] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2007] [Revised: 06/19/2007] [Accepted: 07/06/2007] [Indexed: 11/22/2022]
Abstract
In previous studies, we identified sedative effects of Scutellaria baicalensis extracts and found that these extracts or their constituents may also have anticonvulsive effects. Wogonin is a natural product isolated from S. baicalensis, which possesses central nervous system effects such as anxiolytic and neuroprotective activities. In this study, we investigated the effects of wogonin on convulsion related behaviors, such as myorelaxation, motor coordination, and anticonvulsant effects of wogonin on chemical induced seizure and electroshock seizure in mice or rats. The effect of wogonin on membrane potential was also observed. Wogonin was intraperitoneally injected into mice or rats 30 min prior to testing. Animals treated with wogonin did not change locomotor activities as well as endurance times on the rota-rod, which indicates that wogonin did not cause a sedative and myorelaxation effect. Wogonin significantly blocked convulsion induced by pentylenetetrazole and electroshock but not convulsion induced by strychnine. Wogonin also significantly reduced the electrogenic response score, but flumazenil treatment reversed this decrease to the level of the control group. The wogonin treatment increased Cl(-)influx into the intracellular area as dose increased. Flumazenil and bicuculline treatment, however, inhibited the Cl(-) influx induced by wogonin. These results indicate that the anticonvulsive effects produced by wogonin were mediated by the GABAergic neuron.
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Affiliation(s)
- Hyung Geun Park
- Department of Pharmacy, Sahmyook University, Seoul 139-742, Republic of Korea
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Abstract
PURPOSE OF REVIEW Status epilepticus refractory to first and second-line anticonvulsants represents an outstanding challenge to the medical team. This review covers new insights into the anaesthetic and intensive care of status epilepticus. RECENT FINDINGS In the anaesthetic treatment of status epilepticus, barbiturates, midazolam, or propofol are the drugs of choice, but the lack of controlled prospective data as yet does not allow the recommendation of a preference for one of the substances, unequivocally. Recent observational studies reported on inhalational anaesthetics and supplementary nonanaesthetics such as levetiracetam or topiramate that may be administered if status epilepticus is not controlled by intravenous anaesthetics. Nonpharmacological approaches including resective surgery, brain stimulation, and hypothermia may be applied in selected patients, only. Psychogenic nonepileptic status epilepticus commonly mimics refractory generalized convulsive status epilepticus, and clinical features discerning the two conditions are presented. The underlying cause is the major contributor for a difficult-to-treat 'malignant' course of status epilepticus and together with age determines mortality and functional outcome. SUMMARY The common substances administered for the anaesthetic treatment of status epilepticus require assessment in a prospective randomized controlled trial. Alternative pharmacological or nonpharmacological approaches need further studies as well before they can be recommended as part of the therapeutic regime.
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Affiliation(s)
- Martin Holtkamp
- Department of Neurology, Charité Universitätsmedizin Berlin, Berlin, Germany.
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Abstract
Refractory status epilepticus (RSE) is an important and serious clinical problem that typically requires prolonged and high-level intensive care, and is often associated with poor outcome. This review addresses some of the current issues concerning the management of RSE, including recent definitions used for clinical studies, epidemiology, clinical course, and outcome. Current approaches to treatment, including the now relatively standard use of intravenous anesthetic agents, as well as emerging therapies utilizing drugs such as valproate and topiramate, are discussed as well.
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Affiliation(s)
- Daniel H Lowenstein
- Department of Neurology, University of California, San Francisco, CA 94143, USA.
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Chung SS, Wang NC, Treiman DM. Comparative Efficacy and Safety of Antiepileptic Drugs for the Treatment of Status Epilepticus. J Pharm Pract 2007. [DOI: 10.1177/0897190007305134] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Status epilepticus (SE) is a medical emergency with high mortality rate. Common causes of SE include noncompliance with antiepileptic medications, drug- and alcohol-related etiologies, and central nervous system (CNS) infections. Because prolonged seizures can cause neuronal damage, treatment should be initiated promptly to avoid potential complications. Previous studies support intravenous (IV) lorazepam as first-line therapy and IV phenytoin or fosphenytoin as a second-line medication. If first-and second-line medications fail to control SE, further treatment with propofol, pentobarbital, midazolam, or other medications should be considered. Many of the drugs currently used to control SE are associated with sedation, respiratory suppression, hypotension, cardiac dysrhythmia, and anaphylactic reactions. Therefore, IV valproate or other newer antiepileptic drugs may be considered as an alternative third-line therapy for those who cannot tolerate the hypotensive effects of other anticonvulsants. This paper reviews comparative effectiveness and safety concerns among frequently used medications for SE.
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Affiliation(s)
- Steve S. Chung
- Epilepsy Research and Monitoring Unit, Neurology Residency Program, Department of Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona,
| | - Norman C. Wang
- Department of Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
| | - David M. Treiman
- Department of Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona
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Kyrkou M, Harbord M, Kyrkou N, Kay D, Coulthard K. Community use of intranasal midazolam for managing prolonged seizures. JOURNAL OF INTELLECTUAL & DEVELOPMENTAL DISABILITY 2006; 31:131-8. [PMID: 16954090 DOI: 10.1080/13668250600847021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
BACKGROUND Until a few years ago, rectal diazepam (RD) was the only option available to parents and carers managing prolonged seizures. However, its use in the community was limited due to the requirement for privacy, and because education staff in South Australia are not permitted to carry out invasive procedures. METHOD Following a literature review, a seizure management training package was developed to enhance the implementation of a trial treatment protocol for the administration of intranasal midazolam (INM). Parents, carers and education staff were later surveyed about their experiences and perceptions. RESULTS Intranasal midazolam was administered to 131 people (51 children and 80 adults), with 96.9% control of seizures, and only one minor adverse event. Parents expressed a preference for INM over RD because of the shorter time it took to take effect and wear off, and the ability to administer it in public if necessary. CONCLUSION Intranasal midazolam is a safe and practical alternative to rectal diazepam for managing prolonged seizures in the community.
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Affiliation(s)
- Margaret Kyrkou
- Children, Youth and Women's Health Service, South Australia.
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Gilby KL, Da Silva AG, McIntyre DC. Differential GABAA Subunit Expression Following Status Epilepticus in Seizure-prone and Seizure-resistant Rats: A Putative Mechanism for Refractory Drug Response. Epilepsia 2005; 46 Suppl 5:3-9. [PMID: 15987246 DOI: 10.1111/j.1528-1167.2005.01001.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE Two rat strains were selectively bred to be prone (Fast) or resistant (Slow) to amygdala kindling. The first objective of this experiment was to determine whether that selection was specific to kindling or was sensitive more broadly to another seizure induction agent, kainic acid (KA). Second, we investigated whether these strains exhibit distinct molecular responses to KA with respect to GABA(A) receptor subunit expression. METHODS Development of status epilepticus (SE) was profiled in Fast and Slow rats injected with 20 mg/kg KA (i.p.). Two hours post-SE onset, rats received a sedative dose of sodium pentobarbital. Behavioral profiles included latency to SE, number of wet dog shakes (WDS), and number and duration of stage 3-5 generalized seizures. Rats were killed 24 h post-SE, and alpha(1) and alpha(4) mRNA levels were compared in the hippocampus and amygdala using QPCR. RESULTS Slow rats exhibited a much greater latency to SE onset (p < 0.01) and many more WDS (p < 0.01) than Fast rats. During SE, Fast rats spent more time in and exhibited more repeated bouts of generalized stage 3-5 seizures (p < 0.01) than Slow rats. Constitutive levels of alpha1 and alpha4 were not different between the strains in either structure and equivalent reductions in alpha4 were evident 24 h post-SE. However, while Fast rats showed KA-induced reductions in alpha1 in both structures, Slow rats showed significant elevations. CONCLUSIONS Genetic selection for temporal lobe excitability, manifested as differential amygdala kindling rates, is paralleled by vulnerability to KA-induced SE. Further, these strains exhibited at least one opposing molecular response to SE, namely alpha1 expression. This finding may offer a putative mechanism through which seemingly similar epilepsies can be intractable in some patients but treatable in others.
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MESH Headings
- Amygdala/metabolism
- Amygdala/physiology
- Animals
- Anticonvulsants/pharmacology
- Disease Models, Animal
- Disease Susceptibility/metabolism
- Excitatory Amino Acid Agonists/pharmacology
- Gene Expression/drug effects
- Gene Expression/genetics
- Genetic Predisposition to Disease/genetics
- Hippocampus/metabolism
- Hippocampus/physiology
- Kainic Acid/pharmacology
- Kindling, Neurologic/drug effects
- Kindling, Neurologic/genetics
- Kindling, Neurologic/metabolism
- Male
- Peptide Fragments/genetics
- Peptide Fragments/metabolism
- Polymerase Chain Reaction/methods
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Long-Evans
- Rats, Wistar
- Receptors, GABA-A/genetics
- Receptors, GABA-A/metabolism
- Seizures/chemically induced
- Seizures/genetics
- Species Specificity
- Status Epilepticus/chemically induced
- Status Epilepticus/metabolism
- Transcription, Genetic/drug effects
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Affiliation(s)
- Krista L Gilby
- Department of Psychology, Life Sciences Research Center, Carleton University, Ottawa, Ontario, Canada.
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Abstract
Status epilepticus is a major medical emergency associated with significant morbidity and mortality. Status epilepticus is best defined as a continuous, generalized, convulsive seizure lasting > 5 min, or two or more seizures during which the patient does not return to baseline consciousness. Lorazepam in a dose of 0.1 mg/kg is the drug of first choice for terminating status epilepticus. Patients who continue to have clinical or EEG evidence of seizure activity after treatment with lorazepam should be considered to have refractory status epileptics and should be treated with a continuous infusion of propofol or midazolam. This article reviews current information regarding the management of status epilepticus in adults.
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Affiliation(s)
- Paul E Marik
- Department of Critical Care Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
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Bender RA, Dubé C, Baram TZ. Febrile Seizures and Mechanisms of Epileptogenesis: Insights from an Animal Model. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2004; 548:213-25. [PMID: 15250596 PMCID: PMC3086822 DOI: 10.1007/978-1-4757-6376-8_15] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
Temporal lobe epilepsy (TLE) is the most prevalent type of human epilepsy, yet the causes for its development, and the processes involved, are not known. Most individuals with TLE do not have a family history, suggesting that this limbic epilepsy is a consequence of acquired rather than genetic causes. Among suspected etiologies, febrile seizures have frequently been cited. This is due to the fact that retrospective analyses of adults with TLE have demonstrated a high prevalence (20-->60%) of a history of prolonged febrile seizures during early childhood, suggesting an etiological role for these seizures in the development of TLE. Specifically, neuronal damage induced by febrile seizures has been suggested as a mechanism for the development of mesial temporal sclerosis, the pathological hallmark of TLE. However, the statistical correlation between febrile seizures and TLE does not necessarily indicate a causal relationship. For example, preexisting (genetic or acquired) 'causes' that result independently in febrile seizures and in TLE would also result in tight statistical correlation. For obvious reasons, complex febrile seizures cannot be induced in the human, and studies of their mechanisms and of their consequences on brain molecules and circuits are severely limited. Therefore, an animal model was designed to study these seizures. The model reproduces the fundamental key elements of the human condition: the age specificity, the physiological temperatures seen in fevers of children, the length of the seizures and their lack of immediate morbidity. Neuroanatomical, molecular and functional methods have been used in this model to determine the consequences of prolonged febrile seizures on the survival and integrity of neurons, and on hyperexcitability in the hippocampal-limbic network. Experimental prolonged febrile seizures did not lead to death of any of the seizure-vulnerable populations in hippocampus, and the rate of neurogenesis was also unchanged. Neuronal function was altered sufficiently to promote synaptic reorganization of granule cells, and transient and long-term alterations in the expression of specific genes were observed. The contribution of these consequences of febrile seizures to the epileptogenic process is discussed.
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Affiliation(s)
- Roland A Bender
- Department of Anatomy, University of California at Irvine, USA
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Galustyan SG, Walsh-Kelly CM, Szewczuga D, Bergholte J, Hennes H. The short-term outcome of seizure management by prehospital personnel: a comparison of two protocols. Pediatr Emerg Care 2003; 19:221-5. [PMID: 12972817 DOI: 10.1097/01.pec.0000086234.54586.49] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate the impact of an emergency medical service protocol with reduced diazepam dose on the intubation rate of children with seizure activity treated by emergency medical service personnel and to evaluate the short-term outcome comparing 2 emergency medical service treatment protocols. METHODS Retrospective review of the emergency medical service and hospital databases of children 0-18 years with seizure activity. Prior to January 1996, the county emergency medical service protocol recommended a diazepam dose of 0.2-0.5 mg/kg i.v. or pr for termination of seizure activity (group 1). As of January 1996, the diazepam dose was reduced to 0.05-0.1 mg/kg i.v. or pr (group 2). Demographics, emergency medical service and emergency department interventions, and disposition data were abstracted. RESULTS 1516 subjects met the enrollment criteria: 1003 (66%) in group 1 and 513 (34%) in group 2. Emergency medical service administered diazepam to 288 subjects: 189 (19%) in group 1 and 99 (19%) in group 2. Twenty (7%) of all treated subjects required intubation: 19 in group 1 and 1 in group 2 (relative risk 9.7, 95% CI 1.30-72.5). Mean diazepam dose was 0.17 mg/kg in group 1 and 0.13 mg/kg in group 2 (mean difference 0.04, 95% CI 0.02-0.06). No significant difference in the requirement for repeated anticonvulsant dose, complications, or emergency department interventions was noted. However, hospital admission rate was lower in group 2 (rate difference 0.06, 95% CI 0.01-0.11). CONCLUSIONS Our study demonstrated a reduction in intubation rate and a need for hospitalization in the reduced diazepam dose emergency medical service protocol. The reduction in the diazepam dose was effective in terminating the seizure activity and did not increase the risk of adverse events.
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Affiliation(s)
- Sergey G Galustyan
- Emergency Medicine Section, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, USA
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Affiliation(s)
- Patricia G Hosking
- University College Hospitals NHS Trust, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK.
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Abstract
PURPOSE Accumulating evidence implicates drug-transporter proteins ABCB1 and ABCC1 in resistance to multiple antiepileptic drugs (AEDs) in refractory epilepsy. These proteins are upregulated in surgically resected human brain tissue containing epileptogenic pathologies, including cortical dysplasia. In surgically resected cases, no upregulation is seen in normal adjacent tissue, suggesting that neither seizures nor prolonged exposure to AEDs need induce ABCB1 or ABCC1 expression. We wished to determine if status epilepticus might cause upregulation of these proteins. METHODS Immunohistochemistry was performed for ABCB1 and ABCC1 in postmortem human brain tissue from a patient who died in status epilepticus and was found to have unihemispheric cortical dysplasia. RESULTS There was upregulation of both proteins, as expected, in the hemisphere containing dysplasia. There also was widespread upregulation of both proteins in glia from the normal hemisphere. Previous work shows that drug treatment does not cause such upregulation. CONCLUSIONS Upregulation of these proteins in histologically normal brain tissue is most likely the result of seizures in status, as seen in animal models. The findings provide a possible explanation for the appearance of AED resistance in prolonged status and emphasise the importance of prompt treatment of status epilepticus.
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Affiliation(s)
- Sanjay M Sisodiya
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London, London, England.
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Abstract
Neurotransmitter receptor systems have been the focus of intensive pharmacological research for more than 20 years for basic and applied scientific reasons, but only recently has there been a better understanding of their key features. One of these systems includes the type A receptor for the gamma-aminobutyric acid (GABA), which forms an integral anion channel from a pentameric subunit assembly and mediates most of the fast inhibitory neurotransmission in the adult vertebrate central nervous system. Up to now, depending on the definition, 16-19 mammalian subunits have been cloned and localized on different genes. Their assembly into proteins in a poorly defined stoichiometry forms the basis of functional and pharmacological GABA(A) receptor diversity, i.e. the receptor subtypes. The latter has been well documented in autoradiographic studies using ligands that label some of the receptors' various binding sites, corroborated by recombinant expression studies using the same tools. Significantly less heterogeneity has been found at the physiological level in native receptors, where the subunit combinations have been difficult to dissect. This review focuses on the characteristics, use and usefulness of various ligands and their binding sites to probe GABA(A) receptor properties and to gain insight into the biological function from fish to man and into evolutionary conserved GABA(A) receptor heterogeneity. We also summarize the properties of the novel mouse models created for the study of various brain functions and review the state-of-the-art imaging of brain GABA(A) receptors in various human neuropsychiatric conditions. The data indicate that the present ligands are only partly satisfactory tools and further ligands with subtype-selective properties are needed for imaging purposes and for confirming the behavioral and functional results of the studies presently carried out in gene-targeted mice with other species, including man.
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Affiliation(s)
- Esa R Korpi
- Department of Pharmacology and Clinical Pharmacology, University of Turku, Itäinen Pitkäkatu 4B, Finland.
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Abstract
Status epilepticus is a medical emergency that requires rapid and vigorous treatment to prevent neuronal damage and systemic complications. Failure to diagnose and treat status epilepticus accurately and effectively results in significant morbidity and mortality. Cerebral metabolic decompensation occurs after approximately 30 min of uncontrolled convulsive activity, and the window for treatment is therefore limited. Therapy should proceed simultaneously on four fronts: termination of seizures; prevention of seizure recurrence once status is controlled; management of precipitating causes of status epilepticus; management of the complications. This article reviews current opinions about the classification, aetiology and pathophysiology of adult generalised convulsive status epilepticus and details practical management strategies for treatment of this life-threatening condition.
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Affiliation(s)
- M G Chapman
- Department of Neuroanaesthesia and Intensive Care, The National Hospital for Neurology and Neurosurgery, University College London Hospitals, Queen Square, London WC1N 3BG, UK
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Saghatelyan AK, Gorissen S, Albert M, Hertlein B, Schachner M, Dityatev A. The extracellular matrix molecule tenascin-R and its HNK-1 carbohydrate modulate perisomatic inhibition and long-term potentiation in the CA1 region of the hippocampus. Eur J Neurosci 2000; 12:3331-42. [PMID: 10998116 DOI: 10.1046/j.1460-9568.2000.00216.x] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Perisomatic inhibition of pyramidal cells regulates efferent signalling from the hippocampus. The striking presence of HNK-1, a carbohydrate expressed by neural adhesion molecules, on perisomatic interneurons and around somata of CA1 pyramidal neurons led us to apply monoclonal HNK-1 antibodies to acute murine hippocampal slices. Injection of these antibodies decreased GABAA receptor-mediated perisomatic inhibitory postsynaptic currents (pIPSCs) but did not affect dendritic IPSCs or excitatory postsynaptic currents. The decrease in the mean amplitude of evoked pIPSCs by HNK-1 antibodies was accompanied by an increase in the coefficient of variation of pIPSC amplitude, number of failures and changes in frequency but not amplitude of miniature IPSCs, suggesting that HNK-1 antibodies reduced efficacy of evoked GABA release. HNK-1 antibodies did not affect pIPSCs in knock-out mice deficient in the extracellular matrix molecule tenascin-R which carries the HNK-1 carbohydrate as analysed by immunoblotting in synaptosomal fractions prepared from the CA1 region of the hippocampus. For control, HNK-1 antibody was applied to acute sections of mice deficient in the neural cell adhesion molecule NCAM, another potential carrier of HNK-1, and resulted in decrease of pIPSCs as observed in wild-type mice. Reduction in perisomatic inhibition is expected to promote induction of long-term potentiation (LTP) by increasing the level of depolarization during theta-burst stimulation. Indeed, LTP was increased by HNK-1 antibody applied before stimulation. Moreover, LTP was reduced by an HNK-1 peptide mimic, but not control peptide. These results provide first evidence that tenascin-R and its associated HNK-1 carbohydrate modulate perisomatic inhibition and synaptic plasticity in the hippocampus.
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Affiliation(s)
- A K Saghatelyan
- Zentrum für Molekulare Neurobiologie, Universität Hamburg, Martinistrasse 52, D-20246 Hamburg, Germany
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Abstract
Valproic acid (VA) has been reported to be effective in status epilepticus (SE) when given rectally. More recently, intravenous (IV) VA has been demonstrated to be effective and safe. Pharmacokinetic studies and initial clinical experience with IV valproic acid suggest that it may have a useful role in the management of refractory status epilepticus, but the magnitude of its utility is not possible to quantify or compare with phenytoin and phenobarbital. In simple SE, IV VA provides less additional benefit, since standard therapy usually works well. IV VA may be useful as a substitute for standard simple SE therapy, but this is difficult to justify unless adverse reactions to standard therapy are anticipated. The published pediatric experience with IV VA for SE is scant.
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Affiliation(s)
- L G Yamamoto
- Department of Pediatrics, University of Hawaii John A. Burns School of Medicine, Honolulu, USA.
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