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Perampanel, Michael A. Rogawski

Michael A. Rogawski

No abstract provided.

A New Sv2a Ligand For Epilepsy, Michael A. Rogawski

Michael A. Rogawski

Mechanisms Of Action Of Antiseizure Drugs And The Ketogenic Diet., Michael Rogawski, Jong Rho, Wolfgang Löscher

Michael A. Rogawski

Perampanel Inhibition Of Ampa Receptor Currents In Cultured Hippocampal Neurons, Chao-Yin Chen, Lucas Matt, Johannes Hell, Michael Rogawski

Michael A. Rogawski

Perampanel is an aryl substituted 2-pyridone AMPA receptor antagonist that was recently approved as a treatment for epilepsy. The drug potently inhibits AMPA receptor responses but the mode of block has not been characterized. Here the action of perampanel on AMPA receptors was investigated by whole-cell voltage-clamp recording in cultured rat hippocampal neurons. Perampanel caused a slow (τ~1 s at 3 µM), concentration-dependent inhibition of AMPA receptor currents evoked by AMPA and kainate. The rates of block and unblock of AMPA receptor currents were 1.5×105 M−1 s−1 and 0.58 s−1, respectively. Perampanel did not affect NMDA receptor currents. The extent …

Pediatric Super-Refractory Status Epilepticus Treated With Allopregnanolone, Eileen Broomall, Joanne Natale, Michele Grimason, Joshua Goldstein, Craig Smith, Celia Chang, Stephen Kanes, Michael Rogawski, Mark Wainwright

Michael A. Rogawski

Super-refractory status epilepticus is a life-threatening condition. Resistance to benzodiazepine and barbiturate treatment for this disorder is thought to be due to internalization of synaptic GABA-A receptors, and withdrawal of benzodiazepines and barbiturates during treatment often triggers seizure recurrence. The neurosteroid allopregnanolone acts as a positive allosteric modulator of synaptic and extrasynaptic GABA-A receptors. Here we describe the use of allopregnanolone in two pediatric patients with super-refractory status epilepticus. This treatment allowed the general anesthetic infusions to be weaned with resolution of status epilepticus. This is the first report of allopregnanolone use to treat status epilepticus in children.

Anticonvulsant Potencies Of The Enantiomers Of The Neurosteroids Androsterone And Etiocholanolone Exceed Those Of The Natural Forms, Dorota Zolkowska, Ashish Dhir, Kathiresan Krishnan, Douglas F. Covey, Michael A. Rogawski

Michael A. Rogawski

RATIONALE: Androsterone [(3α,5α)-3-hydroxyandrostan-17-one; 5α,3α-A] and its 5β-epimer etiocholanolone [(3α,5β)-3-hydroxyandrostan-17-one; 5β,3α-A)], the major excreted metabolites of testosterone, are neurosteroid positive modulators of GABA-A receptors. Such neurosteroids typically show enantioselectivity in which the natural form is more potent than the corresponding unnatural enantiomer. For 5α,3α-A and 5β,3α-A, the unnatural enantiomers are more potent at GABA-A receptors than the natural forms. OBJECTIVES: The aim of this study was to compare the anticonvulsant potencies and time courses of 5α,3α-A and 5β,3α-A with their enantiomers in mouse seizure models. METHODS: Steroids were administered intraperitoneally to male NIH Swiss mice 15 min (or up to 6 …

Proconvulsant Actions Of Intrahippocampal Botulinum Neurotoxin B In The Rat, Sonja Bröer, Dorota Zolkowska, Manuela Gernert, Michael A. Rogawski

Michael A. Rogawski

Botulinum neurotoxins (BoNTs) may affect the excitability of brain circuits by inhibiting neurotransmitter release at central synapses. There is evidence that local delivery of BoNT serotypes A and E, which target synaptosomal-associated protein 25, a component of the release machinery specific to excitatory synapses, can inhibit seizure generation. BoNT serotype B (BoNT/B) targets VAMP2, which is expressed in both excitatory and inhibitory terminals. Here we assessed the effects of unilateral intrahippocampal infusion of BoNT/B in the rat on intravenous pentylenetetrazol (PTZ) seizure thresholds, and on the expression of spontaneous behavioral and electrographic seizures. Infusion of BoNT/B (500 and 1000 Unit) …

Seizure Protection By Intrapulmonary Delivery Of Midazolam In Mice, Ashish Dhir, Dorota Zolkowska, Michael A. Rogawski

Michael A. Rogawski

The lung provides a portal of entry that could be used to rapidly deliver anticonvulsant substances to the brain to treat seizures. In the present study, we demonstrate that midazolam, a water-soluble anticonvulsant benzodiazepine, confers potent seizure protection when administered via the intrapulmonary route. High dose (100 mg/kg) intraperitoneal midazolam induced loss-of-righting reflex in mice. Lower doses of midazolam (100–1000 μg/kg) when administered intraperitoneally did not induce loss-of-righting reflex but protected animals against pentylenetetrazol (PTZ)-induced seizures. Intrapulmonary administration of midazolam via a tracheal cannula protected against intraperitoneal PTZ seizures at lower doses. The minimal intraperitoneal and intravenous doses of midazolam …

Epilepsy Therapy Development: Technical And Methodologic Issues In Studies With Animal Models, Aristea S. Galanopoulou, Merab Kokaia, Jeffrey A. Loeb, Astrid Nehlig, Asla Pitkanen, Michael A. Rogawski, Kevin J. Staley, Vicky H. Whittemore, F. Edward Dudek

Michael A. Rogawski

The search for new treatments for seizures, epilepsies, and their comorbidities faces considerable challenges. This is due in part to gaps in our understanding of the etiology and pathophysiology of most forms of epilepsy. An additional challenge is the difficulty in predicting the efficacy, tolerability, and impact of potential new treatments on epilepsies and comorbidities in humans, using the available resources. Herein we provide a summary of the discussions and proposals of the Working Group 2 as presented in the Joint American Epilepsy Society and International League Against Epilepsy Translational Workshop in London (September 2012). We propose methodologic and reporting …

Issues Related To Development Of New Antiseizure Treatments, Karen S. Wilcox, Tracy Dixon-Salazar, Graeme J. Sills, Elinor Ben-Menachem, H. Steve White, Roger J. Porter, Marc A. Dichter, Solomon L. Moshe, Jeffrey L. Noebels, Michael D. Privitera, Michael A. Rogawski

Michael A. Rogawski

This report represents a summary of the discussions led by the antiseizure treatment working group of the International League Against Epilepsy (ILAE)/American Epilepsy Society (AES) Working Groups joint meeting in London (London Meeting). We review here what is currently known about the pharmacologic characteristics of current models of refractory seizures, both for adult and pediatric epilepsy. In addition, we address how the National Institute of Neurological Disorders and Stroke (NINDS)-funded Anticonvulsant Screening Program (ASP) is evolving to incorporate appropriate animal models in the search for molecules that might be sufficiently novel to warrant further pharmacologic development. We also briefly address …

Neuroactive Steroids For The Treatment Of Status Epilepticus, Michael Rogawski, Carlos Loya, Kiran Reddy, Dorota Zolkowski, Christoph Lossin

Michael A. Rogawski

Benzodiazepines are the current first-line standard-of-care treatment for status epilepticus but fail to terminate seizures in about one third of cases. Synaptic GABA-A receptors, which mediate phasic inhibition in central circuits, are the molecular target of benzodiazepines. As status epilepticus progresses, these receptors are internalized and become functionally inactivated, conferring benzodiazepine resistance, which is believed to be a major cause of treatment failure. GABA-A receptor positive allosteric modulator neuroactive steroids, such as allopregnanolone, also potentiate synaptic GABA-A receptors, but in addition they enhance extrasynaptic GABA-A receptors that mediate tonic inhibition. Extrasynaptic GABA-A receptors are not internalized, and desensitization of these …

The Intrinsic Severity Hypothesis Of Pharmacoresistance To Antiepileptic Drugs, Michael Rogawski

Michael A. Rogawski

Pharmacoresistance to antiepileptic drugs (AEDs) is a barrier to seizure freedom for many persons with epilepsy. For nearly two decades, pharmacoresistance has been framed in terms of factors affecting the access of AEDs to their molecular targets in the brain or the actions of the drugs on these targets. Shortcomings in this prevailing view led to the formulation of the intrinsic severity hypothesis of pharmacoresistance to AEDs, which is based on the recognition that there are neurobiologic factors that confer phenotypic variation among individuals with etiologically similar forms of epilepsy and postulates that more severe epilepsy is more difficult to …

Antiepileptic Drugs And Migraine, Michael Rogawski

Michael A. Rogawski

Prepared for the 16th International Headache Research Seminar, “Innovative Drug Development For Headache Disorders,” March 23–25, 2007, Copenhagen, Denmark.

Epilepsy, Michael Rogawski

Michael A. Rogawski

No abstract provided.