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Magro G, Laterza V. Status epilepticus: Is there a Stage 1 plus? Epilepsia 2024. [PMID: 38507275 DOI: 10.1111/epi.17953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 03/02/2024] [Accepted: 03/04/2024] [Indexed: 03/22/2024]
Abstract
In status epilepticus (SE), "time is brain." Currently, first-line therapy consists of benzodiazepines (BDZs) and SE is classified by the response to treatment; stage 2 or established SE is defined as "BDZ-resistant SE." Nonetheless, this classification does not always work, especially in the case of prolonged convulsive SE, where many molecular changes occur and γ-aminobutyric acid signaling becomes excitatory. Under these circumstances, BDZ therapy might not be optimal, and might be possibly detrimental, if given alone; as the duration of SE increases, so too does BDZ resistance. Murine models of SE showed how these cases might benefit more from synergistic combined therapy from the start. The definition of Stage 1 plus is suggested, as a stage requiring combined therapy from the start, which includes prolonged SE with seizure activity going on for >10 min, the time that marks the disruption of receptor homeostasis, with increased internalization. This specific stage might require a synergistic approach from the start, with a combination of first- and second-line treatment.
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Affiliation(s)
- Giuseppe Magro
- Department of Medical and Surgical Sciences, Institute of Neurology, Magna Græcia University, Catanzaro, Italy
| | - Vincenzo Laterza
- Department of Medical and Surgical Sciences, Institute of Neurology, Magna Græcia University, Catanzaro, Italy
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Nguyen DA, Stone MF, Schultz CR, de Araujo Furtado M, Niquet J, Wasterlain CG, Lumley LA. Evaluation of Midazolam-Ketamine-Allopregnanolone Combination Therapy against Cholinergic-Induced Status Epilepticus in Rats. J Pharmacol Exp Ther 2024; 388:376-385. [PMID: 37770198 PMCID: PMC10801769 DOI: 10.1124/jpet.123.001784] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 09/01/2023] [Accepted: 09/06/2023] [Indexed: 10/03/2023] Open
Abstract
Status epilepticus (SE) is a life-threatening development of self-sustaining seizures that becomes resistant to benzodiazepines when treatment is delayed. Benzodiazepine pharmacoresistance is thought in part to result from internalization of synaptic GABAA receptors, which are the main target of the drug. The naturally occurring neurosteroid allopregnanolone is a therapy of interest against SE for its ability to modulate all isoforms of GABAA receptors. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been partially effective in combination with benzodiazepines in mitigating SE-associated neurotoxicity. In this study, allopregnanolone as an adjunct to midazolam or midazolam-ketamine combination therapy was evaluated for efficacy against cholinergic-induced SE. Adult male rats implanted with electroencephalographic (EEG) telemetry devices were exposed to the organophosphorus chemical (OP) soman (GD) and treated with an admix of atropine sulfate and HI-6 at 1 minute after exposure followed by midazolam, midazolam-allopregnanolone, or midazolam-ketamine-allopregnanolone 40 minutes after seizure onset. Neurodegeneration, neuronal loss, and neuroinflammation were assessed 2 weeks after GD exposure. Seizure activity, EEG power integral, and epileptogenesis were also compared among groups. Overall, midazolam-ketamine-allopregnanolone combination therapy was effective in reducing cholinergic-induced toxic signs and neuropathology, particularly in the thalamus and hippocampus. Higher dosage of allopregnanolone administered in combination with midazolam and ketamine was also effective in reducing EEG power integral and epileptogenesis. The current study reports that there is a promising potential of neurosteroids in combination with benzodiazepine and ketamine treatments in a GD model of SE. SIGNIFICANCE STATEMENT: Allopregnanolone, a naturally occurring neurosteroid, reduced pathologies associated with soman (GD) exposure such as epileptogenesis, neurodegeneration, and neuroinflammation, and suppressed GD-induced toxic signs when used as an adjunct to midazolam and ketamine in a delayed treatment model of soman-induced status epilepticus (SE) in rats. However, protection was incomplete, suggesting that further studies are needed to identify optimal combinations of antiseizure medications and routes of administration for maximal efficacy against cholinergic-induced SE.
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Affiliation(s)
- Donna A Nguyen
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland (D.A.N., M.F.S., C.R.S., L.A.L.); BioSEaD, LLC, Rockville, Maryland (M.D.A.F.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California (J.N., C.G.W.); and Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California (J.N., C.G.W.)
| | - Michael F Stone
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland (D.A.N., M.F.S., C.R.S., L.A.L.); BioSEaD, LLC, Rockville, Maryland (M.D.A.F.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California (J.N., C.G.W.); and Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California (J.N., C.G.W.)
| | - Caroline R Schultz
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland (D.A.N., M.F.S., C.R.S., L.A.L.); BioSEaD, LLC, Rockville, Maryland (M.D.A.F.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California (J.N., C.G.W.); and Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California (J.N., C.G.W.)
| | - Marcio de Araujo Furtado
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland (D.A.N., M.F.S., C.R.S., L.A.L.); BioSEaD, LLC, Rockville, Maryland (M.D.A.F.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California (J.N., C.G.W.); and Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California (J.N., C.G.W.)
| | - Jerome Niquet
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland (D.A.N., M.F.S., C.R.S., L.A.L.); BioSEaD, LLC, Rockville, Maryland (M.D.A.F.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California (J.N., C.G.W.); and Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California (J.N., C.G.W.)
| | - Claude G Wasterlain
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland (D.A.N., M.F.S., C.R.S., L.A.L.); BioSEaD, LLC, Rockville, Maryland (M.D.A.F.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California (J.N., C.G.W.); and Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California (J.N., C.G.W.)
| | - Lucille A Lumley
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland (D.A.N., M.F.S., C.R.S., L.A.L.); BioSEaD, LLC, Rockville, Maryland (M.D.A.F.); Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California (J.N., C.G.W.); and Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California (J.N., C.G.W.)
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Niquet J, Nguyen D, de Araujo Furtado M, Lumley L. Treatment of cholinergic-induced status epilepticus with polytherapy targeting GABA and glutamate receptors. Epilepsia Open 2023; 8 Suppl 1:S117-S140. [PMID: 36807554 PMCID: PMC10173853 DOI: 10.1002/epi4.12713] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 02/15/2023] [Indexed: 02/23/2023] Open
Abstract
Despite new antiseizure medications, the development of cholinergic-induced refractory status epilepticus (RSE) continues to be a therapeutic challenge as pharmacoresistance to benzodiazepines and other antiseizure medications quickly develops. Studies conducted by Epilepsia. 2005;46:142 demonstrated that the initiation and maintenance of cholinergic-induced RSE are associated with trafficking and inactivation of gamma-aminobutyric acid A receptors (GABAA R) thought to contribute to the development of benzodiazepine pharmacoresistance. In addition, Dr. Wasterlain's laboratory reported that increased N-methyl-d-aspartate receptors (NMDAR) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR) contribute to enhanced glutamatergic excitation (Neurobiol Dis. 2013;54:225; Epilepsia. 2013;54:78). Thus, Dr. Wasterlain postulated that targeting both maladaptive responses of reduced inhibition and increased excitation that is associated with cholinergic-induced RSE should improve therapeutic outcome. We currently review studies in several animal models of cholinergic-induced RSE that demonstrate that benzodiazepine monotherapy has reduced efficacy when treatment is delayed and that polytherapy with drugs that include a benzodiazepine (eg midazolam and diazepam) to counter loss of inhibition, concurrent with an NMDA antagonist (eg ketamine) to reduce excitation provide improved efficacy. Improved efficacy with polytherapy against cholinergic-induced seizure is demonstrated by reduction in (1) seizure severity, (2) epileptogenesis, and (3) neurodegeneration compared with monotherapy. Animal models reviewed include pilocarpine-induced seizure in rats, organophosphorus nerve agent (OPNA)-induced seizure in rats, and OPNA-induced seizure in two mouse models: (1) carboxylesterase knockout (Es1-/- ) mice which, similarly to humans, lack plasma carboxylesterase and (2) human acetylcholinesterase knock-in carboxylesterase knockout (KIKO) mice. We also review studies showing that supplementing midazolam and ketamine with a third antiseizure medication (valproate or phenobarbital) that targets a nonbenzodiazepine site rapidly terminates RSE and provides further protection against cholinergic-induced SE. Finally, we review studies on the benefits of simultaneous compared with sequential drug treatments and the clinical implications that lead us to predict improved efficacy of early combination drug therapies. The data generated from seminal rodent studies of efficacious treatment of cholinergic-induced RSE conducted under Dr. Wasterlain's guidance suggest that future clinical trials should treat the inadequate inhibition and temper the excess excitation that characterize RSE and that early combination therapies may provide improved outcome over benzodiazepine monotherapy.
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Affiliation(s)
- Jerome Niquet
- Department of NeurologyDavid Geffen School of Medicine at UCLALos AngelesCaliforniaUSA
- Epilepsy Research LaboratoryVeterans Affairs Greater Los Angeles Healthcare SystemLos AngelesCaliforniaUSA
| | - Donna Nguyen
- Neuroscience DepartmentU.S. Army Medical Research Institute of Chemical Defense (USAMRICD)Aberdeen Proving GroundMarylandUSA
| | | | - Lucille Lumley
- Neuroscience DepartmentU.S. Army Medical Research Institute of Chemical Defense (USAMRICD)Aberdeen Proving GroundMarylandUSA
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Abstract
Status epilepticus (SE) remains a significant cause of morbidity and mortality and often is refractory to standard first-line treatments. A rapid loss of synaptic inhibition and development of pharmacoresistance to benzodiazepines (BZDs) occurs early during SE, while NMDA and AMPA receptor antagonists remain effective treatments after BZDs have failed. Multimodal and subunit-selective receptor trafficking within minutes to an hour of SE involves GABA-A, NMDA, and AMPA receptors and contributes to shifts in the number and subunit composition of surface receptors with differential impacts on the physiology, pharmacology, and strength of GABAergic and glutamatergic currents at synaptic and extrasynaptic sites. During the first hour of SE, synaptic GABA-A receptors containing γ2 subunits move to the cell interior while extrasynaptic GABA-A receptors with δ subunits are preserved. Conversely, NMDA receptors containing N2B subunits are increased at synaptic and extrasynaptic sites, and homomeric GluA1 ("GluA2-lacking") calcium permeant AMPA receptor surface expression also is increased. Molecular mechanisms, largely driven by NMDA receptor or calcium permeant AMPA receptor activation early during circuit hyperactivity, regulate subunit-specific interactions with proteins involved with synaptic scaffolding, adaptin-AP2/clathrin-dependent endocytosis, endoplasmic reticulum (ER) retention, and endosomal recycling. Reviewed here is how SE-induced shifts in receptor subunit composition and surface representation increase the excitatory to inhibitory imbalance that sustains seizures and fuels excitotoxicity contributing to chronic sequela such as "spontaneous recurrent seizures" (SRS). A role for early multimodal therapy is suggested both for treatment of SE and for prevention of long-term comorbidities.
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Affiliation(s)
- David E Naylor
- VA Greater Los Angeles Healthcare System, Department of Neurology, David Geffen School of Medicine at UCLA, and The Lundquist Institute at Harbor-UCLA Medical Center, Los Angeles, California, USA
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Huang TH, Lai MC, Chen YS, Huang CW. The Roles of Glutamate Receptors and Their Antagonists in Status Epilepticus, Refractory Status Epilepticus, and Super-Refractory Status Epilepticus. Biomedicines 2023; 11:biomedicines11030686. [PMID: 36979664 PMCID: PMC10045490 DOI: 10.3390/biomedicines11030686] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 02/18/2023] [Accepted: 02/21/2023] [Indexed: 03/30/2023] Open
Abstract
Status epilepticus (SE) is a neurological emergency with a high mortality rate. When compared to chronic epilepsy, it is distinguished by the durability of seizures and frequent resistance to benzodiazepine (BZD). The Receptor Trafficking Hypothesis, which suggests that the downregulation of γ-Aminobutyric acid type A (GABAA) receptors, and upregulation of N-methyl-D-aspartate (NMDA) and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors play major roles in the establishment of SE is the most widely accepted hypothesis underlying BZD resistance. NMDA and AMPA are ionotropic glutamate receptor families that have important excitatory roles in the central nervous system (CNS). They are both essential in maintaining the normal function of the brain and are involved in a variety of neuropsychiatric diseases, including epilepsy. Based on animal and human studies, antagonists of NMDA and AMPA receptors have a significant impact in ending SE; albeit most of them are not yet approved to be in clinically therapeutic guidelines, due to their psychomimetic adverse effects. Although there is still a dearth of randomized, prospective research, NMDA antagonists such as ketamine, magnesium sulfate, and the AMPA antagonist, perampanel, are regarded to be reasonable optional adjuvant therapies in controlling SE, refractory SE (RSE) or super-refractory SE (SRSE), though there are still a lack of randomized, prospective studies. This review seeks to summarize and update knowledge on the SE development hypothesis, as well as clinical trials using NMDA and AMPA antagonists in animal and human studies of SE investigations.
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Affiliation(s)
- Tzu-Hsin Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70142, Taiwan
- Zhengxin Neurology & Rehabilitation Center, Tainan 70459, Taiwan
| | - Ming-Chi Lai
- Department of Pediatrics, Chi-Mei Medical Center, Tainan 71004, Taiwan
| | - Yu-Shiue Chen
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70142, Taiwan
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70142, Taiwan
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Manna SSS. Dual effects of anandamide in the antiepileptic activity of diazepam in pentylenetetrazole-induced seizures in mice. Behav Pharmacol 2022; 33:527-541. [PMID: 36094027 DOI: 10.1097/fbp.0000000000000700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The prototype endocannabinoid, anandamide activates both CB 1 and transient receptor potential vanilloid type 1 channels (TRPV1) receptor at different concentrations. At high concentrations, anandamide-mediated TRPV1 effects are opposite to its effects at low concentrations via CB 1 receptor. Thus, synaptic concentrations of anandamide govern the neuronal activity and consequently might affect the response of a drug. This study was undertaken to investigate the influence of high and low doses of anandamide on the anticonvulsant action of diazepam on the subcutaneous dose of pentylenetetrazole (PTZ) in Swiss mice weighing 20-25 g. Results revealed that intracerebroventricular administration of capsazepine (a TRPV1 antagonist: 1, 10, or 100 µg/mouse) and the low doses (10 µg/mouse) of anandamide, AM404 (anandamide transport inhibitor), or URB597 (fatty acid amide hydrolase inhibitor) augmented the anticonvulsant effect of diazepam. Conversely, higher dose of anandamide, AM404, URB597 (100 µg/mouse) as well as capsaicin (a TRPV1 agonist: 1, 10, or 100 µg/mouse) attenuated the protective effect of diazepam against PTZ-induced seizures. Thus, this study demonstrates that the effects of diazepam may be augmented by activating CB 1 receptors or dampened via TRPV1 receptors. The findings of the present study can be extrapolated to understand the use of TRPV1 blockers alone or in combination of benzodiazepines in the treatment of benzodiazepines-refractory status epilepticus, a condition associated with maladaptive trafficking of synaptic gamma-aminobutyric acid and glutamate receptors. However, potential clinical applications are needed to further support such preclinical studies.
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Sivakumar S, Ghasemi M, Schachter SC. Targeting NMDA Receptor Complex in Management of Epilepsy. Pharmaceuticals (Basel) 2022; 15:ph15101297. [PMID: 36297409 PMCID: PMC9609646 DOI: 10.3390/ph15101297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 10/17/2022] [Accepted: 10/20/2022] [Indexed: 11/05/2022] Open
Abstract
N-methyl-D-aspartate receptors (NMDARs) are widely distributed in the central nervous system (CNS) and play critical roles in neuronal excitability in the CNS. Both clinical and preclinical studies have revealed that the abnormal expression or function of these receptors can underlie the pathophysiology of seizure disorders and epilepsy. Accordingly, NMDAR modulators have been shown to exert anticonvulsive effects in various preclinical models of seizures, as well as in patients with epilepsy. In this review, we provide an update on the pathologic role of NMDARs in epilepsy and an overview of the NMDAR antagonists that have been evaluated as anticonvulsive agents in clinical studies, as well as in preclinical seizure models.
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Affiliation(s)
- Shravan Sivakumar
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
| | - Mehdi Ghasemi
- Department of Neurology, University of Massachusetts Chan Medical School, Worcester, MA 01655, USA
- Correspondence: (M.G.); (S.C.S.)
| | - Steven C. Schachter
- Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA
- Harvard Medical School, Boston, MA 02114, USA
- Consortia for Improving Medicine with Innovation & Technology (CIMIT), Boston, MA 02114, USA
- Correspondence: (M.G.); (S.C.S.)
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Siddiqui MA, Asad M, Akhter J, Hoda U, Rastogi S, Arora I, Aggarwal NB, Samim M. Resveratrol-Loaded Glutathione-Coated Collagen Nanoparticles Attenuate Acute Seizures by Inhibiting HMGB1 and TLR-4 in the Hippocampus of Mice. ACS Chem Neurosci 2022; 13:1342-1354. [PMID: 35385256 DOI: 10.1021/acschemneuro.2c00171] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Epilepsy is a relatively complicated neurological disorder that results in seizures. The use of resveratrol in treating seizures has been reported in recent studies. However, the low bioavailability of resveratrol and the difficulty of reaching the targeted location in the brain reduce its efficacy considerably. The side effects due to the higher concentration of drugs are another matter of concern. The purpose of the present study is to enhance the antiepileptic potential of resveratrol by delivering it to the brain's targeted location by encapsulating it in glutathione-coated collagen nanoparticles. The collagen nanoparticles increase the bioavailability of resveratrol, while the transport of resveratrol to its target location in the brain is facilitated by glutathione. By encapsulating resveratrol in glutathione-coated collagen nanoparticles, the concentration also substantially decreases. Resveratrol encapsulated in synthesized nanoparticles is referred to as nanoresveratrol. In the present study, nanoresveratrol effectiveness was studied through PTZ-induced seizures (PTZ-IS) and the increasing current electroshock (ICES) test. The efficacy of nanoresveratrol was further established using biochemical analysis, histopathological examinations, ELISA and real-time-PCR tests, and immunohistochemistry examination of the hippocampus of mice. Hence, this study is unique in the sense that it synthesized nanoresveratrol by using glutathione-coated collagen nanoparticles, followed by its application to treating seizures. On the basis of the study results, nanoresveratrol was found to be effective in preventing cognitive impairment in the mice and controlling epilepsy seizures to a greater extent than resveratrol. The proposed nanoformulation also reduces the concentration of resveratrol considerably. The present study results show that even 0.4 mg/kg of nanoresveratrol outperforms 40 mg/kg of resveratrol.
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Affiliation(s)
- Mobin A. Siddiqui
- Department of Chemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, 110062, India
| | - Mohammad Asad
- Department of Biotechnology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, 110062, India
| | - Juheb Akhter
- Department of Medical Elementology and Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, 110062, India
| | - Ubedul Hoda
- Centre for Translational and Clinical Research, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, 110062, India
| | - Shweta Rastogi
- Department of Chemistry, Hansraj College, Delhi University, Delhi, 110007, India
| | - Indu Arora
- Department of Biomedical Sciences, Shaheed Rajguru College of Applied Sciences, New Delhi, 110096, India
| | - Nidhi B. Aggarwal
- Centre for Translational and Clinical Research, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, 110062, India
| | - Mohammed Samim
- Department of Chemistry, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, 110062, India
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Zhou R, Wang Y, Cao X, Li Z, Yu J. Diazepam Monotherapy or Diazepam-Ketamine Dual Therapy at Different Time Points Terminates Seizures and Reduces Mortality in a Status Epilepticus Animal Model. Med Sci Monit 2021; 27:e934043. [PMID: 34866132 PMCID: PMC8662960 DOI: 10.12659/msm.934043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/08/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Being refractory to drugs remains an urgent treatment problem in status epilepticus (SE). The fact that γ-aminobutyric acid A receptors (GABAARs) become internalized and inactive, N-methyl-D-aspartate receptors (NMDARs) become externalized and active during SE may explain the refractoriness to benzodiazepine. However, the real-time dynamic efficacy of antiepileptic drugs remains unclear. Therefore, we propose a hypothesis that diazepam monotherapy or diazepam-ketamine dual therapy could terminate seizures and reduce mortality in the SE model at different time points during ongoing SE. MATERIAL AND METHODS An SE model was established in adult Sprague-Dawley rats with lithium and pilocarpine. The GABAAR agonist diazepam was injected at 5, 10, 20, or 30 min when SE continued. In addition, diazepam and the NMDAR antagonist ketamine were injected at 10 to 60 min at 6 different time points. We measured seizure-free rates, seizure duration, degree of behavioral seizure, and mortality. RESULTS Diazepam monotherapy at 5 min and 10 min from the beginning of SE was able to terminate seizures and improved survival rates. Diazepam-ketamine dual therapy at 10 min, 20 min, and 30 min from the beginning of SE terminated seizures and achieved high survival rates. CONCLUSIONS In this parallel randomized controlled trial with a rat model, we found that diazepam monotherapy was an effective antiepileptic strategy at the early stage of SE less than 10 min after SE onset. If SE lasts more than 10 min but less than 30 min, the diazepam-ketamine dual therapy strategy may be an appropriate choice.
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Affiliation(s)
- Ruijiao Zhou
- Department of Neurology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan, PR China
| | - Yanlin Wang
- Department of Clinical Medicine, North Sichuan Medical College, Nanchong, Sichuan, PR China
| | - Xing Cao
- Department of Neurology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan, PR China
| | - Zhimin Li
- Department of Neurology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan, PR China
| | - Juming Yu
- Department of Neurology, The Affiliated Hospital of North Sichuan Medical College, Nanchong, Sichuan, PR China
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Huang TH, Lai MC, Chen YS, Huang CW. Status Epilepticus Mortality Risk Factors and a Correlation Survey with the Newly Modified STESS. Healthcare (Basel) 2021; 9:healthcare9111570. [PMID: 34828616 PMCID: PMC8622169 DOI: 10.3390/healthcare9111570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 11/04/2021] [Accepted: 11/16/2021] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Status epilepticus (SE) is a neurological emergency and is usually associated with significant morbidity and mortality rates. Several clinical scales have been proposed to predict the clinical outcome of such incidents, including the Status Epilepticus Severity Score (STESS), the modified STESS (mSTESS), and the Encephalitis-Nonconvulsive Status Epilepticus-Diazepam Resistance-Image Abnormalities-Tracheal intubation (END-IT). Nevertheless, there is still a need for a more practical and precise predictive scale. METHODS This is a retrospective cohort study which examines data from patients with SE in our Department of Neurology between 2009 and 2020. Based on the outcome of each case, the patients were divided into survivor and non-survivor groups. We analyzed the independent factors and adjusted the STESS to achieve a better prediction of prognosis. The predictive accuracy of our new STESS scale was then compared with that of the mSTESS and the END-IT. RESULTS Data on a total of 59 patients were collected, with 6 of them classified as non-survivors. The effects of the variables of age, sex, underlying disease(s), and type(s) of antiepileptic drug (AED) use showed no significant differences between the survivor and non-survivor groups. Importantly, the number of AEDs used in the first week and the use of thiobarbiturates predicted non-survival. We adjusted the STESS to create the newly modified STESS (nSTESS), which showed a better predictive capacity than the STESS, the mSTESS, and the END-IT. CONCLUSIONS Our adjustment of the STESS with the addition of the factors "number of AEDs within the first week" and "use of thiobarbiturates", could have a positive impact on the prediction of mortality rates compared with currently used scales. This nSTESS could potentially be useful in clinical practices, for the early prediction of outcomes for patients with SE.
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Affiliation(s)
- Tzu-Hsin Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan; (T.-H.H.); (Y.-S.C.)
| | - Ming-Chi Lai
- Department of Pediatrics, Chi-Mei Medical Center, Tainan 70101, Taiwan;
| | - Yu-Shiue Chen
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan; (T.-H.H.); (Y.-S.C.)
| | - Chin-Wei Huang
- Department of Neurology, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan; (T.-H.H.); (Y.-S.C.)
- Correspondence: ; Tel.: +886-6-2353535-5485; Fax: +886-6-2374285
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Lumley LA, Marrero-Rosado B, Rossetti F, Schultz CR, Stone MF, Niquet J, Wasterlain CG. Combination of antiseizure medications phenobarbital, ketamine, and midazolam reduces soman-induced epileptogenesis and brain pathology in rats. Epilepsia Open 2021; 6:757-769. [PMID: 34657398 PMCID: PMC8633481 DOI: 10.1002/epi4.12552] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/07/2021] [Accepted: 10/12/2021] [Indexed: 12/16/2022] Open
Abstract
Objective Cholinergic‐induced status epilepticus (SE) is associated with a loss of synaptic gamma‐aminobutyric acid A receptors (GABAAR) and an increase in N‐methyl‐D‐aspartate receptors (NMDAR) and amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptors (AMPAR) that may contribute to pharmacoresistance when treatment with benzodiazepine antiseizure medication is delayed. The barbiturate phenobarbital enhances inhibitory neurotransmission by binding to a specific site in the GABAAR to increase the open state of the channel, decrease neuronal excitability, and reduce glutamate‐induced currents through AMPA/kainate receptors. We hypothesized that phenobarbital as an adjunct to midazolam would augment the amelioration of soman‐induced SE and associated neuropathological changes and that further protection would be provided by the addition of an NMDAR antagonist. Methods We investigated the efficacy of combining antiseizure medications to include a benzodiazepine and a barbiturate allosteric GABAAR modulator (midazolam and phenobarbital, respectively) to correct loss of inhibition, and ketamine to reduce excitation caused by increased synaptic localization of NMDAR and AMPAR, which are NMDA‐dependent. Rats implanted with transmitters to record electroencephalographic (EEG) activity were exposed to soman and treated with atropine sulfate and HI‐6 one min after exposure and with antiseizure medication(s) 40 minutes after seizure onset. Results The triple therapy combination of phenobarbital, midazolam, and ketamine administered at 40 minutes after seizure onset effectively prevented soman‐induced epileptogenesis and reduced neurodegeneration. In addition, dual therapy with phenobarbital and midazolam or ketamine was more effective than monotherapy (midazolam or phenobarbital) in reducing cholinergic‐induced toxicity. Significance Benzodiazepine efficacy is drastically reduced with time after seizure onset and inversely related to seizure duration. To overcome pharmacoresistance in severe benzodiazepine‐refractory cholinergic‐induced SE, simultaneous drug combination to include drugs that target both the loss of inhibition (eg, midazolam, phenobarbital) and the increased excitatory response (eg, ketamine) is more effective than benzodiazepine or barbiturate monotherapy.
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Affiliation(s)
- Lucille A Lumley
- Neuroscience Department, U.S. Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland, USA
| | - Brenda Marrero-Rosado
- Neuroscience Department, U.S. Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland, USA
| | - Franco Rossetti
- Military Psychiatry and Neuroscience Department, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA
| | - Caroline R Schultz
- Neuroscience Department, U.S. Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland, USA
| | - Michael F Stone
- Neuroscience Department, U.S. Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, Maryland, USA
| | - Jerome Niquet
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.,Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, USA
| | - Claude G Wasterlain
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.,Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, California, USA
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12
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Godau J, Bharad K, Rösche J, Nagy G, Kästner S, Weber K, Bösel J. Automated Pupillometry for Assessment of Treatment Success in Nonconvulsive Status Epilepticus. Neurocrit Care 2021; 36:148-156. [PMID: 34331202 DOI: 10.1007/s12028-021-01273-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/11/2021] [Indexed: 12/13/2022]
Abstract
BACKGROUND Altered pupillary function may reflect nonconvulsive status epilepticus (NCSE). Neurological pupil index (NPi) assessed by automated pupillometry is a surrogate marker of global pupillary function. We aimed to assess NPi changes in relation to NCSE treatment response. METHODS In this prospective observational study, serial automated pupillometry was performed in 68 NCSE episodes. In accordance with local standards, patients were treated with clonazepam (1-2 mg), levetiracetam (40 mg/kg), and lacosamide (5 mg/kg) in a stepwise approach under continuous electroencephalography monitoring until NCSE was terminated. Patients with refractory NCSE received individualized regimens. NPi was assessed bilaterally before and after each treatment step. For statistical analysis, the lower NPi of both sides (minNPi) was used. Nonparametric testing for matched samples and Cohen's d to estimate effect size were performed. Principal component analysis was applied to assess the contribution of baseline minNPi, age, sex, and NCSE duration to treatment outcome. RESULTS In 97.1% of 68 episodes, NCSE could be terminated; in 16.2%, NCSE was refractory. In 85.3% of episodes, an abnormal baseline minNPi ≤ 4.0 was obtained. After NCSE termination, minNPi increased significantly (p < 0.001). Cohen's d showed a strong effect size of 1.24 (95% confidence interval 0.88-1.61). Baseline minNPi was higher in clonazepam nonresponders vs. responders (p = 0.008), minNPi increased in responders (p < 0.001) but not in nonresponders. NCSE refractivity was associated with normal baseline minNPi (principal component analysis, component 1, 32.6% of variance, r = 0.78), male sex, and longer NCSE duration (component 2, 27.1% of variance, r = 0.62 and r = 0.78, respectively). CONCLUSIONS Automated pupillometry may be a helpful noninvasive neuromonitoring tool for the assessment of patients with NCSE and response to treatment.
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Affiliation(s)
- Jana Godau
- Department of Neurology, Klinikum Kassel, Kassel, Germany. .,Emergency Department, Klinikum Kassel, Kassel, Germany.
| | - Kaushal Bharad
- Department of Neurology, Klinikum Kassel, Kassel, Germany.,Emergency Department, Klinikum Kassel, Kassel, Germany
| | - Johannes Rösche
- Department of Neurology, Klinikum Kassel, Kassel, Germany.,Department of Neurology, University of Rostock, Rostock, Germany
| | - Gabor Nagy
- Department of Neurology, Klinikum Kassel, Kassel, Germany.,Department of Neurosurgery, Klinikum Kassel, Kassel, Germany
| | | | - Klaus Weber
- Emergency Department, Klinikum Kassel, Kassel, Germany
| | - Julian Bösel
- Department of Neurology, Klinikum Kassel, Kassel, Germany
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13
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Abstract
Seizures are frequently triggered by an inciting event and result from uninhibited excitation and/or decreased inhibition of a pool of neurons. If physiologic seizure abortive mechanisms fail, the ensuing unrestrained synchronization of neurons-status epilepticus-can be life-threatening and is associated with the potential for marked morbidity in survivors and high medical care costs. Prognosis is intimately related to etiology and its response to therapeutic measures. Timely implementation of pharmacologic therapy while concurrently performing a stepwise workup for etiology are paramount. Neurodiagnostic testing should guide titration of pharmacologic therapies, and help determine if there is a role for immune modulation.
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Affiliation(s)
- Pouya Alexander Ameli
- Department of Neurology, University of Florida McKnight Brain Institute, 1149 Newell Drive, Gainesville, FL 32610, USA; Department of Neurosurgery, University of Florida McKnight Brain Institute, 1149 Newell Drive, Gainesville, FL 32610, USA
| | - Abdalla A Ammar
- Department of Pharmacy, Yale New Haven Health, 55 Park Street, New Haven, CT 06511, USA
| | - Kent A Owusu
- Department of Pharmacy, Yale New Haven Health, 55 Park Street, New Haven, CT 06511, USA; Care Signature, Yale New Haven Health, 20 York Street, New Haven, CT, 06510, USA
| | - Carolina B Maciel
- Department of Neurology, University of Florida McKnight Brain Institute, 1149 Newell Drive, Gainesville, FL 32610, USA; Department of Neurosurgery, University of Florida McKnight Brain Institute, 1149 Newell Drive, Gainesville, FL 32610, USA; Department of Neurology, Yale University, 20 York Street, New Haven, CT, 06510, USA; Department of Neurology, University of Utah, 383 Colorow Drive, Salt Lake City, UT, 84132, USA.
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14
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Abstract
The canonical mechanism of organophosphate (OP) neurotoxicity is the inhibition of acetylcholinesterase (AChE). However, multiple lines of evidence suggest that mechanisms in addition to or other than AChE inhibition contribute to the neurotoxic effects associated with acute and chronic OP exposures. Characterizing the role(s) of AChE inhibition versus noncholinergic mechanisms in OP neurotoxicity remains an active area of research with significant diagnostic and therapeutic implications. Here, we review recently published studies that provide mechanistic insights regarding (1) OP-induced status epilepticus, (2) long-term neurologic consequences of acute OP exposures, and (3) neurotoxic effects associated with repeated low-level OP exposures. Key data gaps and challenges are also discussed.
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Affiliation(s)
- Yi-Hua Tsai
- Department of Molecular Sciences, University of California, Davis School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Pamela J Lein
- Department of Molecular Sciences, University of California, Davis School of Veterinary Medicine, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
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15
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Reddy DS, Zaayman M, Kuruba R, Wu X. Comparative profile of refractory status epilepticus models following exposure of cholinergic agents pilocarpine, DFP, and soman. Neuropharmacology 2021; 191:108571. [PMID: 33878303 DOI: 10.1016/j.neuropharm.2021.108571] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 03/24/2021] [Accepted: 04/13/2021] [Indexed: 12/12/2022]
Abstract
Status epilepticus (SE) is a medical emergency with continuous seizure activity that causes profound neuronal damage, morbidity, or death. SE incidents can arise spontaneously but mostly are elicited by seizurogenic triggers. Chemoconvulsants such as the muscarinic agonist pilocarpine and, organophosphates (OP) such as the pesticide diisopropylfluorophosphate (DFP) and, the nerve agent soman, can induce SE. Pilocarpine, DFP, and soman share a common feature of cholinergic crisis that transitions into a state of refractory SE, but their comparative profiles remain unclear. Here, we evaluated the comparative convulsant profile of pilocarpine, DFP, and soman to produce refractory SE and brain damage in rats. Behavioral and electrographic seizures were monitored for 24 h after exposure, and the extent of brain injury was determined by histological markers of neuronal injury and degeneration. Seizures were elicited rather slowly after pilocarpine as compared to DFP or soman, which caused rapid onset of spiking that swiftly developed into persistent SE. Time-course of SE activity after DFP was comparable to that after soman, a potent nerve agent. Diazepam controlled pilocarpine-induced SE, but it was ineffective in reducing OP-induced SE. All three agents produced modestly different degrees of neuronal injury and neurodegeneration in the brain. These results reveal distinct convulsant and neuronal injury patterns following exposure to cholinergic agonists, OP pesticides, and nerve agents. A battery of SE models, especially SE induced by cholinergic agents and other etiologies including epilepsy and brain tumors, is essential to identify novel anticonvulsant therapies for the management of refractory SE.
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Affiliation(s)
- Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center College of Medicine, Bryan, TX, 77807, USA.
| | - Marcus Zaayman
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center College of Medicine, Bryan, TX, 77807, USA
| | - Ramkumar Kuruba
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center College of Medicine, Bryan, TX, 77807, USA
| | - Xin Wu
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center College of Medicine, Bryan, TX, 77807, USA
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16
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Lumley L, Niquet J, Marrero-Rosado B, Schultz M, Rossetti F, de Araujo Furtado M, Wasterlain C. Treatment of acetylcholinesterase inhibitor-induced seizures with polytherapy targeting GABA and glutamate receptors. Neuropharmacology 2021; 185:108444. [PMID: 33359073 PMCID: PMC7944923 DOI: 10.1016/j.neuropharm.2020.108444] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/30/2020] [Accepted: 12/17/2020] [Indexed: 12/12/2022]
Abstract
The initiation and maintenance of cholinergic-induced status epilepticus (SE) are associated with decreased synaptic gamma-aminobutyric acid A receptors (GABAAR) and increased N-methyl-d-aspartate receptors (NMDAR) and amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptors (AMPAR). We hypothesized that trafficking of synaptic GABAAR and glutamate receptors is maladaptive and contributes to the pharmacoresistance to antiseizure drugs; targeting these components should ameliorate the pathophysiological consequences of refractory SE (RSE). We review studies of rodent models of cholinergic-induced SE, in which we used a benzodiazepine allosteric GABAAR modulator to correct loss of inhibition, concurrent with the NMDA antagonist ketamine to reduce excitation caused by increased synaptic localization of NMDAR and AMPAR, which are NMDAR-dependent. Models included lithium/pilocarpine-induced SE in rats and soman-induced SE in rats and in Es1-/- mice, which similar to humans lack plasma carboxylesterase, and may better model soman toxicity. These model human soman toxicity and are refractory to benzodiazepines administered at 40 min after seizure onset, when enough synaptic GABAAR may not be available to restore inhibition. Ketamine-midazolam combination reduces seizure severity, epileptogenesis, performance deficits and neuropathology following cholinergic-induced SE. Supplementing that treatment with valproate, which targets a non-benzodiazepine site, effectively terminates RSE, providing further benefit against cholinergic-induced SE. The therapeutic index of drug combinations is also reviewed and we show the improved efficacy of simultaneous administration of midazolam, ketamine and valproate compared to sequential drug administration. These data suggest that future clinical trials should treat both the lack of sufficient inhibition and the excess excitation that characterize RSE, and include early combination drug therapies. This article is part of the special issue entitled 'Acetylcholinesterase Inhibitors: From Bench to Bedside to Battlefield'.
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Affiliation(s)
- Lucille Lumley
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, MD, USA.
| | - Jerome Niquet
- Department of Neurology, David Geffen School of Medicine at UCLA, Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Brenda Marrero-Rosado
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, MD, USA
| | - Mark Schultz
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense (USAMRICD), Aberdeen Proving Ground, MD, USA
| | - Franco Rossetti
- Military Psychiatry and Neuroscience Department, Walter Reed Army Institute of Research, Silver Spring, MD, USA
| | | | - Claude Wasterlain
- Department of Neurology, David Geffen School of Medicine at UCLA, Epilepsy Research Laboratory (151), Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
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17
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Marrero-Rosado BM, Stone MF, de Araujo Furtado M, Schultz CR, Cadieux CL, Lumley LA. Novel Genetically Modified Mouse Model to Assess Soman-Induced Toxicity and Medical Countermeasure Efficacy: Human Acetylcholinesterase Knock-in Serum Carboxylesterase Knockout Mice. Int J Mol Sci 2021; 22:1893. [PMID: 33672922 PMCID: PMC7918218 DOI: 10.3390/ijms22041893] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Revised: 02/06/2021] [Accepted: 02/10/2021] [Indexed: 12/13/2022] Open
Abstract
The identification of improved medical countermeasures against exposure to chemical warfare nerve agents (CWNAs), a class of organophosphorus compounds, is dependent on the choice of animal model used in preclinical studies. CWNAs bind to acetylcholinesterase and prevent the catalysis of acetylcholine, causing a plethora of peripheral and central physiologic manifestations, including seizure. Rodents are widely used to elucidate the effects of CWNA-induced seizure, albeit with a caveat: they express carboxylesterase activity in plasma. Carboxylesterase, an enzyme involved in the detoxification of some organophosphorus compounds, plays a scavenging role and decreases CWNA availability, thus exerting a protective effect. Furthermore, species-specific amino acid differences in acetylcholinesterase confound studies that use oximes or other compounds to restore its function after inhibition by CWNA. The creation of a human acetylcholinesterase knock-in/serum carboxylesterase knockout (C57BL/6-Ces1ctm1.1LocAChEtm1.1Loc/J; a.k.a KIKO) mouse may facilitate better modeling of CWNA toxicity in a small rodent species. The current studies characterize the effects of exposure to soman, a highly toxic CWNA, and evaluate the efficacy of anti-seizure drugs in this newly developed KIKO mouse model. Data demonstrate that a combination of midazolam and ketamine reduces seizure duration and severity, eliminates the development of spontaneous recurrent seizures, and protects certain brain regions from neuronal damage in a genetically modified model with human relevance to organophosphorus compound toxicity. This new animal model and the results of this study and future studies using it will enhance medical countermeasures development for both defense and homeland security purposes.
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Affiliation(s)
- Brenda M. Marrero-Rosado
- Medical Toxicology Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA; (B.M.M.-R.); (M.F.S.); (C.R.S.); (C.L.C.)
| | - Michael F. Stone
- Medical Toxicology Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA; (B.M.M.-R.); (M.F.S.); (C.R.S.); (C.L.C.)
| | - Marcio de Araujo Furtado
- Anatomy, Physiology and Genetics Department, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA;
- BioSEaD, LLC, Rockville, MD 20850, USA
| | - Caroline R. Schultz
- Medical Toxicology Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA; (B.M.M.-R.); (M.F.S.); (C.R.S.); (C.L.C.)
| | - C. Linn Cadieux
- Medical Toxicology Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA; (B.M.M.-R.); (M.F.S.); (C.R.S.); (C.L.C.)
| | - Lucille A. Lumley
- Medical Toxicology Research Division, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA; (B.M.M.-R.); (M.F.S.); (C.R.S.); (C.L.C.)
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18
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Kamdar HA, Hamed M, Smetana KS, Shanmugam K, Peters E, Yasin R, Thakur G, Gopal M, Sawalha K, Greene-Chandos D, Hussein O. Lorazepam timing for acute convulsive seizure control (LoTASC). Seizure 2020; 83:41-47. [PMID: 33080484 DOI: 10.1016/j.seizure.2020.09.024] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/06/2020] [Accepted: 09/23/2020] [Indexed: 12/22/2022] Open
Abstract
INTRODUCTION Guidelines specify early administration of benzodiazepines (BZD) for the management of convulsive status epilepticus. The distinction between acute convulsive seizure and status epilepticus can be misconstrued resulting in BZD administration prior to a patient meeting criteria of status epilepticus. Early BZD administration may theoretically lead to systemic vital instability. Our study aims to assess if administering lorazepam, for convulsive seizures <5 min, causes vital instability. METHODS This is a retrospective study analyzing patients who presented with a seizure lasting <5 min between 2011 and 2016. Continuous variables of lorazepam receivers versus non- receivers were analyzed using t-test for parametric and Mann-Whitney U test for nonparametric data. Categorical variables were analyzed using Chi-Square Test. Subsequently, subjects were analyzed through univariate and multivariate regression models to determine predictors of vital instability. RESULTS Out of 1052 subjects initially screened, 165 were included. Of these, 91 (55 %) received lorazepam, and 74 (45 %) did not. Through univariate and multivariate analyses, there was a significantly higher incidence of vital instability (defined as receipt of a vasopressor or intubation) in patients who received lorazepam (OR = 6.76, 95 % CI = 1.48, 30.95) (p = 0.014). This was dose-dependent (p < 0.0001). It was responsible for 22.5 % of the vital instability. Lorazepam administration significantly prolonged the intensive care unit (ICU) length of stay (0 days [IQR 0 - 0] vs [IQR 0-2.3]; p = 0.038). CONCLUSION Our study suggests that lorazepam administration for acute convulsive seizures not meeting convulsive status epilepticus criteria may lead to iatrogenic vital instability and need for ICU admission.
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Affiliation(s)
- Hera A Kamdar
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
| | - Mohammad Hamed
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
| | - Keaton S Smetana
- The Ohio State University, Wexner Medical Center, Department of Pharmacy, United States.
| | - Kruthika Shanmugam
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
| | - Elizabeth Peters
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
| | - Rabia Yasin
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
| | - Gaurav Thakur
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
| | - Mangala Gopal
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
| | - Khalid Sawalha
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
| | - Diana Greene-Chandos
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
| | - Omar Hussein
- The Ohio State University, Wexner Medical Center, Department of Neurology, United States.
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19
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Marrero-Rosado BM, de Araujo Furtado M, Kundrick ER, Walker KA, Stone MF, Schultz CR, Nguyen DA, Lumley LA. Ketamine as adjunct to midazolam treatment following soman-induced status epilepticus reduces seizure severity, epileptogenesis, and brain pathology in plasma carboxylesterase knockout mice. Epilepsy Behav 2020; 111:107229. [PMID: 32575012 PMCID: PMC7541728 DOI: 10.1016/j.yebeh.2020.107229] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/03/2020] [Accepted: 06/04/2020] [Indexed: 12/18/2022]
Abstract
Delayed treatment of cholinergic seizure results in benzodiazepine-refractory status epilepticus (SE) that is thought, at least in part, to result from maladaptive trafficking of N-methyl-d-aspartate (NMDA) and gamma-aminobutyric acid type A (GABAA) receptors, the effects of which may be ameliorated by combination therapy with the NMDA receptor antagonist ketamine. Our objective was to establish whether ketamine and midazolam dual therapy would improve outcome over midazolam monotherapy following soman (GD) exposure when evaluated in a mouse model that, similar to humans, lacks plasma carboxylesterase, greatly reducing endogenous scavenging of GD. In the current study, continuous cortical electroencephalographic activity was evaluated in male and female plasma carboxylesterase knockout mice exposed to a seizure-inducing dose of GD and treated with midazolam or with midazolam and ketamine combination at 40 min after seizure onset. Ketamine and midazolam combination reduced GD-induced lethality, seizure severity, and the number of mice that developed spontaneous recurrent seizure (SRS) compared with midazolam monotherapy. In addition, ketamine-midazolam combination treatment reduced GD-induced neuronal degeneration and microgliosis. These results support that combination of antiepileptic drug therapies aimed at correcting the maladaptive GABAA and NMDA receptor trafficking reduces the detrimental effects of GD exposure. Ketamine may be a beneficial adjunct to midazolam in reducing the epileptogenesis and neuroanatomical damage that follows nerve agent exposure and pharmacoresistant SE.
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Affiliation(s)
- Brenda M. Marrero-Rosado
- U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD 21010
| | - Marcio de Araujo Furtado
- Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814,BioSEaD, LLC. 451 Hungerford Drive, Rockville, MD, 20850
| | - Erica R. Kundrick
- U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD 21010
| | - Katie A. Walker
- U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD 21010
| | - Michael F. Stone
- U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD 21010
| | - Caroline R. Schultz
- U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD 21010
| | - Donna A. Nguyen
- U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD 21010
| | - Lucille A. Lumley
- U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Road, Aberdeen Proving Ground, MD 21010
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20
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Spampanato J, Bealer SL, Smolik M, Dudek FE. Delayed Adjunctive Treatment of Organophosphate-Induced Status Epilepticus in Rats with Phenobarbital, Memantine, or Dexmedetomidine. J Pharmacol Exp Ther 2020; 375:59-68. [PMID: 32873622 DOI: 10.1124/jpet.120.000175] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 07/16/2020] [Indexed: 12/15/2022] Open
Abstract
Organophosphate (OP) exposure induces status epilepticus (SE), a medical emergency with high morbidity and mortality. Current standard medical countermeasures lose efficacy with time so that treatment delays, in the range of tens of minutes, result in increasingly poor outcomes. As part of the Countermeasures Against Chemical Threats Neurotherapeutics Screening Program, we previously developed a realistic model of delayed treatment of OP-induced SE using the OP diisopropyl fluorophosphate (DFP) to screen compounds for efficacy in the termination of SE and elimination of neuronal death. Male rats were implanted for electroencephalogram (EEG) recordings 7 days prior to experimentation. Rats were then exposed to DFP, and SE was induced for 60 minutes and then treated with midazolam (MDZ) plus one of three antiseizure drugs (ASDs)-phenobarbital (PHB), memantine (MEM), or dexmedetomidine (DMT)-in conjunction with antidotes. EEG was recorded for 24 hours, and brains were stained with Fluoro-Jade B for quantification of degenerating neurons. We found that PHB + MDZ induced a prolonged suppression of SE and reduced neuronal death. MEM + MDZ treatment exacerbated SE and increased mortality; however, surviving rats had fewer degenerating neurons. DMT + MDZ significantly suppressed SE with only a minimal reduction in neuronal death. These data demonstrate that delayed treatment of OP-induced SE with other ASDs, when added to MDZ, can achieve greater seizure suppression with additional reduction in degenerating neurons throughout the brain compared with MDZ alone. The effect of a drug on the severity of seizure activity did not necessarily determine the drug's effect on neuronal death under these conditions. SIGNIFICANCE STATEMENT: This study assesses the relative effectiveness of three different delayed-treatment regimens for the control of organophosphate-induced status epilepticus and reduction of subsequent neuronal death. The data demonstrate the potential for highly effective therapies despite significant treatment delay and a potential disconnect between seizure severity and neuronal death.
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Affiliation(s)
- Jay Spampanato
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, Utah
| | - Steven L Bealer
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, Utah
| | - Melissa Smolik
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, Utah
| | - F Edward Dudek
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, Utah
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Janicot R, Stafstrom CE, Shao LR. 2-Deoxyglucose terminates pilocarpine-induced status epilepticus in neonatal rats. Epilepsia 2020; 61:1528-1537. [PMID: 32558935 DOI: 10.1111/epi.16583] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/27/2020] [Accepted: 05/27/2020] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Neonatal status epilepticus (SE) is a life-threatening medical emergency. Unfortunately, up to 50% of neonates with SE are resistant to current antiseizure drugs, highlighting the need for better treatments. This study aims to explore a novel metabolic approach as a potential alternative treatment to control neonatal SE, using the glycolytic inhibitor 2-deoxyglucose (2-DG). METHODS SE was induced by pilocarpine (300 mg/kg, intraperitoneally [ip]) in neonatal Sprague Dawley rats (postnatal day 10 [P10]-P17) and was monitored by video-electroencephalography (V-EEG). After 30 minutes of SE, 2-DG or one of two conventional antiseizure drugs with different mechanisms of action, phenobarbital or levetiracetam, was administrated ip, and V-EEG recording was continued for ~60 additional minutes. The time to seizure cessation after drug injection, EEG scores, and power spectra before and after drug or saline treatment were used to assess drug effects. RESULTS Once SE became sustained, administration of 2-DG (50, 100, or 500 mg/kg, ip) consistently stopped behavioral and electrographic seizures within 10-15 minutes; lower doses took longer (25-30 minutes) to stop SE, demonstrating a dose-dependent effect. Administration of phenobarbital (30 mg/kg, ip) or levetiracetam (100 mg/kg, ip) also stopped SE within 10-15 minutes in neonatal rats. SIGNIFICANCE Our results suggest that the glycolysis inhibitor 2-DG acts quickly to reduce neuronal hyperexcitability and effectively suppress ongoing seizure activity, which may provide translational value in the treatment of neonatal SE.
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Affiliation(s)
- Remi Janicot
- Division of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Li-Rong Shao
- Division of Pediatric Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland
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Kundrick E, Marrero-Rosado B, Stone M, Schultz C, Walker K, Lee-Stubbs RB, de Araujo Furtado M, Lumley LA. Delayed midazolam dose effects against soman in male and female plasma carboxylesterase knockout mice. Ann N Y Acad Sci 2020; 1479:94-107. [PMID: 32027397 DOI: 10.1111/nyas.14311] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/13/2020] [Accepted: 01/19/2020] [Indexed: 01/30/2023]
Abstract
Chemical warfare nerve agent exposure leads to status epilepticus that may progress to epileptogenesis and severe brain pathology when benzodiazepine treatment is delayed. We evaluated the dose-response effects of delayed midazolam (MDZ) on toxicity induced by soman (GD) in the plasma carboxylesterase knockout (Es1-/- ) mouse, which, similar to humans, lacks plasma carboxylesterase. Initially, we compared the median lethal dose (LD50 ) of GD exposure in female Es1-/- mice across estrous with male mice and observed a greater LD50 during estrus compared with proestrus or with males. Subsequently, male and female GD-exposed Es1-/- mice treated with a dose range of MDZ 40 min after seizure onset were evaluated for survivability, seizure activity, and epileptogenesis. GD-induced neuronal loss and microglial activation were evaluated 2 weeks after exposure. Similar to our previous observations in rats, delayed treatment with MDZ dose-dependently increased survival and reduced seizure severity in GD-exposed mice, but was unable to prevent epileptogenesis, neuronal loss, or gliosis. These results suggest that MDZ is beneficial against GD exposure, even when treatment is delayed, but that adjunct therapies to enhance protection need to be identified. The Es1-/- mouse GD exposure model may be useful to screen for improved medical countermeasures against nerve agent exposure.
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Affiliation(s)
- Erica Kundrick
- US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Maryland
| | - Brenda Marrero-Rosado
- US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Maryland
| | - Michael Stone
- US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Maryland
| | - Caroline Schultz
- US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Maryland
| | - Katie Walker
- US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Maryland
| | - Robyn B Lee-Stubbs
- US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Maryland
| | | | - Lucille A Lumley
- US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, Maryland
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Lumley LA, Rossetti F, de Araujo Furtado M, Marrero-Rosado B, Schultz CR, Schultz MK, Niquet J, Wasterlain CG. Dataset of EEG power integral, spontaneous recurrent seizure and behavioral responses following combination drug therapy in soman-exposed rats. Data Brief 2019; 27:104629. [PMID: 31687442 PMCID: PMC6820070 DOI: 10.1016/j.dib.2019.104629] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 09/25/2019] [Accepted: 09/27/2019] [Indexed: 11/03/2022] Open
Abstract
This article investigated the efficacy of the combination of antiepileptic drug therapy in protecting against soman-induced seizure severity, epileptogenesis and performance deficits. Adult male rats with implanted telemetry transmitters for continuous recording of electroencephalographic (EEG) activity were exposed to soman and treated with atropine sulfate and the oxime HI-6 one minute after soman exposure and with midazolam, ketamine and/or valproic acid 40 min after seizure onset. Rats exposed to soman and treated with medical countermeasures were evaluated for survival, seizure severity, the development of spontaneous recurrent seizure and performance deficits; combination anti-epileptic drug therapy was compared with midazolam monotherapy. Telemetry transmitters were used to record EEG activity, and a customized MATLAB algorithm was used to analyze the telemetry data. Survival data, EEG power integral data, spontaneous recurrent seizure data and behavioral data are illustrated in figures and included as raw data. In addition, edf files of one month telemetry recordings from soman-exposed rats treated with delayed midazolam are provided as supplementary materials. Data presented in this article are related to research articles “Rational Polytherapy in the Treatment of Cholinergic Seizures” [1] and “Early polytherapy for benzodiazepine-refractory status epilepticus [4].
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Affiliation(s)
- Lucille A Lumley
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense, United States
| | | | - Marcio de Araujo Furtado
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense, United States.,Anatomy, Physiology and Genetics Uniformed Services University of Health Sciences, United States
| | - Brenda Marrero-Rosado
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense, United States
| | - Caroline R Schultz
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense, United States
| | - Mark K Schultz
- Neuroscience Department, US Army Medical Research Institute of Chemical Defense, United States
| | - Jerome Niquet
- Department of Neurology, David Geffen School of Medicine at UCLA, United States
| | - Claude G Wasterlain
- Department of Neurology, David Geffen School of Medicine at UCLA, United States
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