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Martinez LA, Born HA, Harris S, Regnier-Golanov A, Grieco JC, Weeber EJ, Anderson AE. Quantitative EEG Analysis in Angelman Syndrome: Candidate Method for Assessing Therapeutics. Clin EEG Neurosci 2023; 54:203-212. [PMID: 33203220 DOI: 10.1177/1550059420973095] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
The goal of these studies was to use quantitative (q)EEG techniques on data from children with Angelman syndrome (AS) using spectral power analysis, and to evaluate this as a potential biomarker and quantitative method to evaluate therapeutics. Although characteristic patterns are evident in visual inspection, using qEEG techniques has the potential to provide quantitative evidence of treatment efficacy. We first assessed spectral power from baseline EEG recordings collected from children with AS compared to age-matched neurotypical controls, which corroborated the previously reported finding of increased total power driven by elevated delta power in children with AS. We then retrospectively analyzed data collected during a clinical trial evaluating the safety and tolerability of minocycline (3 mg/kg/d) to compare pretreatment recordings from children with AS (4-12 years of age) to EEG activity at the end of treatment and following washout for EEG spectral power and epileptiform events. At baseline and during minocycline treatment, the AS subjects demonstrated increased delta power; however, following washout from minocycline treatment the AS subjects had significantly reduced EEG spectral power and epileptiform activity. Our findings support the use of qEEG analysis in evaluating AS and suggest that this technique may be useful to evaluate therapeutic efficacy in AS. Normalizing EEG power in AS therefore may become an important metric in screening therapeutics to gauge overall efficacy. As therapeutics transition from preclinical to clinical studies, it is vital to establish outcome measures that can quantitatively evaluate putative treatments for AS and neurological disorders with distinctive EEG patterns.
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Affiliation(s)
- Luis A Martinez
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA
| | - Heather A Born
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA
| | - Sarah Harris
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA
| | - Angelique Regnier-Golanov
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA
| | - Joseph C Grieco
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Edwin J Weeber
- Department of Molecular Pharmacology and Physiology, University of South Florida, Tampa, FL, USA
| | - Anne E Anderson
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.,The Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA.,The Gordon and Mary Cain Pediatric Neurology Research Foundation Laboratories, Texas Children's Hospital, Houston, TX, USA.,Departments of Neuroscience and Neurology, Baylor College of Medicine, Houston, TX, USA
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Ascoli M, Elia M, Gasparini S, Bonanni P, Mastroianni G, Cianci V, Neri S, Pascarella A, Santangelo D, Aguglia U, Ferlazzo E. Therapeutic approach to neurological manifestations of Angelman syndrome. Expert Rev Clin Pharmacol 2022; 15:843-850. [PMID: 35917229 DOI: 10.1080/17512433.2022.2109463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION Angelman syndrome (AS) is a neurogenetic disorder due to deficient expression of the maternal copy of the UBE3A gene, which encodes ubiquitin ligase E3A protein. Severe developmental delay, seizures and other neurological disorders characterizes AS. AREAS COVERED In this review, we focus on a comprehensive therapeutic approach to the most disabling neurological manifestations of AS: epilepsy, sleep disturbances, behavioral and movement disorders. Articles were identified through PubMed and Google Scholar up to October 2021. EXPERT OPINION Evidence for the treatment of neurological manifestations in AS mainly derives from poor quality studies (case reports, small case series, expert opinions). Seizures can be polymorphic and includes atypical absences, myoclonic, generalized tonic-clonic, unilateral clonic, or atonic attacks. Sodium valproate, levetiracetam and benzodiazepines are the most commonly used anti-seizure medications. Melatonin or mirtazapine seem to improve sleep quality. Antipsychotics, antidepressants and anxiolytics have been proposed for treatment of behavioral manifestations, but no evidence-based studies are available. Non-pharmacological approach may also be useful. Mild dystonia is common but usually does not significantly impact patients' motor performances. Well-conducted clinical trials aimed to evaluate treatment of neurological complications of AS are warranted. Gene and molecular precision therapies represent a fascinating area of research in the future.
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Affiliation(s)
- Michele Ascoli
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | | | - Sara Gasparini
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Paolo Bonanni
- Epilepsy and Neurophysiology Unit, IRCCS Medea, Conegliano, Treviso, Italy
| | - Giovanni Mastroianni
- Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Vittoria Cianci
- Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Sabrina Neri
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Angelo Pascarella
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Domenico Santangelo
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy
| | - Umberto Aguglia
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy.,Institute of Molecular Bioimaging and Physiology, National Research Council, Catanzaro, Italy
| | - Edoardo Ferlazzo
- Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.,Regional Epilepsy Centre, Great Metropolitan Hospital "Bianchi-Melacrino-Morelli", Reggio Calabria, Italy.,Institute of Molecular Bioimaging and Physiology, National Research Council, Catanzaro, Italy
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3
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Samanta D. Pharmacotherapeutic management of seizures in patients with Angleman syndrome. Expert Opin Pharmacother 2022; 23:1511-1522. [PMID: 35862628 DOI: 10.1080/14656566.2022.2105141] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Approximately 80-90% of patients with Angelman syndrome (AS) develop childhood-onset intractable seizures with major negative impact on the quality of life.Thus adequate management of seizures is the most critical priority to improve health-related quality of life in children with AS. AREAS COVERED The primary focus of the review is on pharmacotherapeutic management of seizures. The first part of the review briefly discusses epileptogenesis and polymorphic seizure phenotypes associated with AS to understand pharmacotherapeutic decision-making better. Next, the review explores individual antiseizure medicines (ASMs) and their potential therapeutic utility. Lastly, some future and emerging treatment options are discussed that can transform the management of seizures in patients with AS. EXPERT OPINION Evidence for treating seizures in AS mainly derives from low-quality studies. Levetiracetam and clobazam are the most commonly used ASMs. Although the potential utility of several other ASMs(valproate, topiramate, lamotrigine, ethosuximide, clonazepam) has been well documented for some time, the treatment landscape may rapidly evolve due to the availability of newer and better tolerated ASMs(cannabidiol oil, brivaracetam, perampanel). In addition, a better understanding of the underlying pathogenesis and the development of molecular therapeutics offer hope for precision therapies for seizures.
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Affiliation(s)
- Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas
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4
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Samanta D. Epilepsy in Angelman syndrome: A scoping review. Brain Dev 2021; 43:32-44. [PMID: 32893075 PMCID: PMC7688500 DOI: 10.1016/j.braindev.2020.08.014] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2020] [Revised: 08/17/2020] [Accepted: 08/17/2020] [Indexed: 12/30/2022]
Abstract
Angelman Syndrome (AS) is characterized by severe developmental delays including marked speech impairment, movement abnormalities(ataxia, tremor), and unique behaviors such as frequent laughter and is caused by dysfunctional maternal UBE3A gene (maternal 15q11-13 deletions, maternal specific UBE3A mutation, uniparental disomy, and imprinting defect). Intractable epileptic seizures since early childhood with characteristic EEG abnormalities are present in 80-90% patients with AS. Underlying pathophysiology may involve neocortical and thalamocortical hyperexcitability secondary to severe reduction of GABAergic input, as well as dysfunctional synaptic plasticity, deficient synaptogenesis, and neuronal morphological immaturity. The onset of epilepsy is most prevalent between 1 and 3 years of age; however, approximately 25% of patients developed epilepsy before one year of age. Various types of generalized seizures are most prevalent, with most common types are myoclonic and atypical absence.More than 95% of epilepsy patients may have daily seizures at least for a limited time during early childhood, and two-third patients develop disabling seizures. Fever provoked seizures, and frequent occurrence of nonconvulsive status epilepticus are two unique features. Seizures are frequently pharmacoresistant. Considering underlying prominent GABAergic dysfunction, clinicians had used AEDs that target GABAergic signaling such as valproate, phenobarbital, and clonazepam as first-line therapies for AS. However, due to the unfavorable side effect profile of these AEDs, a recent treatment approach involves priority use of levetiracetam, clobazam, topiramate, lamotrigine, ethosuximide, VNS, and carbohydrate-restricted diets. Besides symptomatic management, there has been recent progress to find a curative treatment with the following approaches: 1. Gene/protein replacement therapy (Adeno and lentiviral vector therapy to deliver a gene or secretory protein); 2. Activation of the intact but silent paternal copy of UBE3A (antisense oligonucleotide therapy and artificial transcription factors); and 3. Downstream therapies (OV101/gaboxadol, ketone supplement, novel compounds/peptides, anti-inflammatory/regenerative therapy).
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Affiliation(s)
- Debopam Samanta
- Child Neurology Section, Department of Pediatrics, University of Arkansas for Medical Sciences, Debopam Samanta 1 Children's Way, Little Rock, AR 72202, USA.
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5
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Absalom NL, Liao VWY, Kothur K, Indurthi DC, Bennetts B, Troedson C, Mohammad SS, Gupta S, McGregor IS, Bowen MT, Lederer D, Mary S, De Waele L, Jansen K, Gill D, Kurian MA, McTague A, Møller RS, Ahring PK, Dale RC, Chebib M. Gain-of-function GABRB3 variants identified in vigabatrin-hypersensitive epileptic encephalopathies. Brain Commun 2020; 2:fcaa162. [PMID: 33585817 PMCID: PMC7869430 DOI: 10.1093/braincomms/fcaa162] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 07/31/2020] [Accepted: 08/28/2020] [Indexed: 01/06/2023] Open
Abstract
Variants in the GABRB3 gene encoding the β3-subunit of the γ-aminobutyric acid type A ( receptor are associated with various developmental and epileptic encephalopathies. Typically, these variants cause a loss-of-function molecular phenotype whereby γ-aminobutyric acid has reduced inhibitory effectiveness leading to seizures. Drugs that potentiate inhibitory GABAergic activity, such as nitrazepam, phenobarbital or vigabatrin, are expected to compensate for this and thereby reduce seizure frequency. However, vigabatrin, a drug that inhibits γ-aminobutyric acid transaminase to increase tonic γ-aminobutyric acid currents, has mixed success in treating seizures in patients with GABRB3 variants: some patients experience seizure cessation, but there is hypersensitivity in some patients associated with hypotonia, sedation and respiratory suppression. A GABRB3 variant that responds well to vigabatrin involves a truncation variant (p.Arg194*) resulting in a clear loss-of-function. We hypothesized that patients with a hypersensitive response to vigabatrin may exhibit a different γ-aminobutyric acid A receptor phenotype. To test this hypothesis, we evaluated the phenotype of de novo variants in GABRB3 (p.Glu77Lys and p.Thr287Ile) associated with patients who are clinically hypersensitive to vigabatrin. We introduced the GABRB3 p.Glu77Lys and p.Thr287Ile variants into a concatenated synaptic and extrasynaptic γ-aminobutyric acid A receptor construct, to resemble the γ-aminobutyric acid A receptor expression by a patient heterozygous for the GABRB3 variant. The mRNA of these constructs was injected into Xenopus oocytes and activation properties of each receptor measured by two-electrode voltage clamp electrophysiology. Results showed an atypical gain-of-function molecular phenotype in the GABRB3 p.Glu77Lys and p.Thr287Ile variants characterized by increased potency of γ-aminobutyric acid A without change to the estimated maximum open channel probability, deactivation kinetics or absolute currents. Modelling of the activation properties of the receptors indicated that either variant caused increased chloride flux in response to low concentrations of γ-aminobutyric acid that mediate tonic currents. We therefore propose that the hypersensitivity reaction to vigabatrin is a result of GABRB3 variants that exacerbate GABAergic tonic currents and caution is required when prescribing vigabatrin. In contrast, drug strategies increasing tonic currents in loss-of-function variants are likely to be a safe and effective therapy. This study demonstrates that functional genomics can explain beneficial and adverse anti-epileptic drug effects, and propose that vigabatrin should be considered in patients with clear loss-of-function GABRB3 variants.
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Affiliation(s)
- Nathan L Absalom
- Faculty of Medicine and Health, School of Pharmacy, Brain and Mind Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Vivian W Y Liao
- Faculty of Medicine and Health, School of Pharmacy, Brain and Mind Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Kavitha Kothur
- Kids Neuroscience Centre at The Children’s Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Dinesh C Indurthi
- Faculty of Medicine and Health, School of Pharmacy, Brain and Mind Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Bruce Bennetts
- Department of Molecular Genetics, The Children’s Hospital at Westmead, Westmead, New South Wales 2145, Australia
- Discipline of Paediatrics and Adolescent Health, The Children's Hospital at Westmead Clinical School, The University of Sydney, 2145, Australia
| | - Christopher Troedson
- T.Y. Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Shekeeb S Mohammad
- Kids Neuroscience Centre at The Children’s Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Sachin Gupta
- T.Y. Nelson Department of Neurology and Neurosurgery, The Children's Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Iain S McGregor
- Faculty of Science, Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Michael T Bowen
- Faculty of Science, Lambert Initiative for Cannabinoid Therapeutics, Brain and Mind Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Damien Lederer
- Institute of Pathology and Genetics, Center for Human Genetics, Gosselies 6041, Belgium
| | - Sandrine Mary
- Institute of Pathology and Genetics, Center for Human Genetics, Gosselies 6041, Belgium
| | - Liesbeth De Waele
- Department of Development and Regeneration, KULeuven, Leuven 3000, Belgium
| | - Katrien Jansen
- Department of Development and Regeneration, KULeuven, Leuven 3000, Belgium
| | - Deepak Gill
- Kids Neuroscience Centre at The Children’s Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Manju A Kurian
- Molecular Neurosciences, UCL Great Ormond Street Institute of Child Health, London WC1E 6BT, UK
- Department of Neurology, Great Ormond Street Hospital for Children, London WC1N 3JH, UK
| | - Amy McTague
- Molecular Neurosciences, UCL Great Ormond Street Institute of Child Health, London WC1E 6BT, UK
- Department of Neurology, Great Ormond Street Hospital for Children, London WC1N 3JH, UK
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund 4293, Denmark
- Department of Regional Health Research, University of Southern Denmark, Odense 5230, Denmark
| | - Philip K Ahring
- Faculty of Medicine and Health, School of Pharmacy, Brain and Mind Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Russell C Dale
- Kids Neuroscience Centre at The Children’s Hospital at Westmead, Westmead, New South Wales 2145, Australia
| | - Mary Chebib
- Faculty of Medicine and Health, School of Pharmacy, Brain and Mind Centre, The University of Sydney, Sydney, New South Wales 2006, Australia
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Egawa K, Kitagawa K, Inoue K, Takayama M, Takayama C, Saitoh S, Kishino T, Kitagawa M, Fukuda A. Decreased tonic inhibition in cerebellar granule cells causes motor dysfunction in a mouse model of Angelman syndrome. Sci Transl Med 2013; 4:163ra157. [PMID: 23220633 DOI: 10.1126/scitranslmed.3004655] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Angelman syndrome is a neurodevelopmental disorder caused by loss of function of the UBE3A gene encoding a ubiquitin E3 ligase. Motor dysfunction is a characteristic feature of Angelman syndrome, but neither the mechanisms of action nor effective therapeutic strategies have yet been elucidated. We report that tonic inhibition is specifically decreased in cerebellar granule cells of Ube3a-deficient mice, a model of Angelman syndrome. As a mechanism underlying this decrease in tonic inhibition, we show that Ube3a controls degradation of γ-aminobutyric acid (GABA) transporter 1 (GAT1) and that deficiency of Ube3a induces a surplus of GAT1 that results in a decrease in GABA concentrations in the extrasynaptic space. Administering low doses of 4,5,6,7-tetrahydroisothiazolo-[5,4-c]pyridin-3-ol (THIP), a selective extrasynaptic GABA(A) receptor agonist, improves the abnormal firing properties of a population of Purkinje cells in cerebellar brain slices and reduces cerebellar ataxia in Ube3a-deficient mice in vivo. These results suggest that pharmacologically increasing tonic inhibition may be a useful strategy for alleviating motor dysfunction in Angelman syndrome.
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Affiliation(s)
- Kiyoshi Egawa
- Department of Neurophysiology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
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Thibert RL, Larson AM, Hsieh DT, Raby AR, Thiele EA. Neurologic manifestations of Angelman syndrome. Pediatr Neurol 2013; 48:271-9. [PMID: 23498559 DOI: 10.1016/j.pediatrneurol.2012.09.015] [Citation(s) in RCA: 117] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Accepted: 09/24/2012] [Indexed: 11/28/2022]
Abstract
Angelman syndrome is a neurogenetic disorder characterized by the loss or reduction of the ubiquitin-protein ligase E3A enzyme. Angelman syndrome results from a deletion or mutation of the maternally inherited 15q11.2-13.1 region, paternal uniparental disomy of chromosome 15, or an imprinting error. Epilepsy is common and may present with multiple seizure types, including nonconvulsive status epilepticus. Seizures are often intractable and typically require broad-spectrum antiepileptic medications. Dietary therapy has also proved successful in Angelman syndrome. Electroencephalographic patterns include notched δ and rhythmic θ activity and epileptiform discharges. Sleep disorders are also common, often characterized by abnormal sleep-wake cycles. Movement disorders are nearly universal in Angelman syndrome, most frequently presenting with ataxia and tremor. Neurocognitive impairment is always present to varying degrees, and expressive speech is typically severely affected. Individuals with Angelman syndrome often manifest psychiatric comorbidities including hyperactivity, anxiety, and challenging behaviors such as aggression and self-injury. We focus on a comprehensive whole-child approach to the diagnosis and long-term clinical care of individuals with Angelman syndrome.
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Affiliation(s)
- Ronald L Thibert
- Pediatric Epilepsy Program and Angelman Syndrome Clinic, Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA
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8
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Faulkner MA, Singh SP. Neurogenetic disorders and treatment of associated seizures. Pharmacotherapy 2013; 33:330-43. [PMID: 23400943 DOI: 10.1002/phar.1201] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Seizures are a frequent complication associated with several neurogenetic disorders. Antiepileptic medications remain the mainstay of treatment in these patients. We summarized the available data associated with various antiepileptic therapies used to treat patients with neurogenetic disorders who experienced recurrent seizures. A MEDLINE search was conducted to identify articles and abstracts describing the use of antiepileptic therapy for the treatment of various neurogenetic syndromes. Of all the neurogenetic syndromes, only autism spectrum disorders, Angelman syndrome, Rett syndrome, Dravet syndrome, and tuberous sclerosis complex were identified as having sufficient published information to evaluate therapy. Some efficacy trends were identified, including frequent successes with valproic acid with clonazepam for epilepsy with Angelman syndrome; valproic acid, stiripentol, and clobazam (triple combination therapy) for epilepsy with Dravet syndrome; and vigabatrin for infantile spasms associated with tuberous sclerosis complex. Due to a paucity of information regarding the mechanisms by which seizures are generated in the various disorders, approach to seizure control is primarily based on clinical experience and a limited amount of study data exploring patient outcomes. Although exposure of the developing brain to antiepileptic medications is of some concern, the control of epileptic activity is an important undertaking in these individuals, as the severity of eventual developmental delay often appears to correlate with the severity of seizures. As such, early aggressive therapy is warranted.
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Affiliation(s)
- Michele A Faulkner
- Departments of Pharmacy Practice and Neurology, Creighton University School of Pharmacy and Health Professions, Omaha, NE68178, USA.
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9
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Abstract
Epileptic myoclonus can be defined as an elementary electroclinical manifestation of epilepsy involving descending neurons, whose spatial (spread) or temporal (self-sustained repetition) amplification can trigger overt epileptic activity and can be classified as cortical (positive and negative), secondarily generalized, thalamo-cortical, and reticular. Cortical epileptic myoclonus represents a fragment of partial or symptomatic generalized epilepsy; thalamo-cortical epileptic myoclonus is a fragment of idiopathic generalized epilepsy. Reflex reticular myoclonus represents the clinical counterpart of fragments of hypersynchronous epileptic activity of neurons in the brainstem reticular formation. Epileptic myoclonus, in the setting of an epilepsy syndrome, can be only one component of a seizure, the only seizure manifestations, one of the multiple seizure types or a more stable condition that is manifested in a nonparoxysmal fashion and mimics a movement disorder. This complex correlation is more obvious in patients with epilepsia partialis continua in which cortical myoclonus and overt focal motor seizures usually start in the same somatic (and cortical) region. In patients with cortical tremor this correlation is less obvious and requires neurophysiological studies to be demonstrated.
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Affiliation(s)
- Renzo Guerrini
- Pediatric Neurology Unit and Laboratories, Children's Hospital A. Meyer - University of Florence, Florence, Italy.
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10
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Abstract
Angelman syndrome is characterized by severe developmental delay, speech impairment, gait ataxia and/or tremulousness of the limbs, and a unique behavioral phenotype that includes happy demeanor and excessive laughter. Microcephaly and seizures are common. Developmental delays are first noted at 3 to 6 months age, but the unique clinical features of the syndrome do not become manifest until after age 1 year. Management includes treatment of gastrointestinal symptoms, use of antiepileptic drugs for seizures, and provision of physical, occupational, and speech therapy with an emphasis on nonverbal methods of communication. The diagnosis rests on a combination of clinical criteria and molecular and/or cytogenetic testing. Analysis of parent-specific DNA methylation imprints in the 15q11.2-q13 chromosome region detects approximately 78% of individuals with lack of maternal contribution. Less than 1% of individuals have a visible chromosome rearrangement. UBE3A sequence analysis detects mutations in an additional 11% of individuals. The remaining 10% of individuals with classic phenotypic features of Angelman syndrome have a presently unidentified genetic mechanism and thus are not amenable to diagnostic testing. The risk to sibs of a proband depends on the genetic mechanism of the loss of the maternally contributed Angelman syndrome/Prader-Willi syndrome region: typically <1% for probands with a deletion or uniparental disomy; as high as 50% for probands with an imprinting defect or a mutation of UBE3A. Members of the mother's extended family are also at increased risk when an imprinting defect or a UBE3A mutation is present. Chromosome rearrangements may be inherited or de novo. Prenatal testing is possible for certain genetic mechanisms.
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Abstract
The newer antiepileptic drugs (AEDs) provide more therapeutic options and overall improved safety and tolerability for patients. To provide the best care, physicians must be familiar with the latest tolerability and safety data. This is particularly true in children, given there are relatively fewer studies examining the effects of AEDs in children compared with adults. Since we now have significant paediatric literature on each of these agents, we provide a comprehensive and current literature review of the newer AEDs, focusing on safety and tolerability data in children and adolescents. Because the safety profiles in children differ from those in adults, familiarity with this literature is important for child neurologists and other paediatric caregivers. We have organized the data by organ system for each AED for easier reference.
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Affiliation(s)
- Dean P Sarco
- Department of Neurology, Division of Epilepsy and Clinical Neurophysiology, Children's Hospital Boston, Boston, Massachusetts, USA.
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12
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Stein D, Chetty M, Rho JM. A "happy" toddler presenting with sudden, life-threatening seizures. Semin Pediatr Neurol 2010; 17:35-8. [PMID: 20434691 DOI: 10.1016/j.spen.2010.02.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Angelman syndrome is often associated with medically refractory epilepsy. Here, we report the case of a young girl with Angelman syndrome who experienced frequent and prolonged atonic seizures associated with dysautonomia and was unresponsive to multiple antiepileptic drugs, but who responded dramatically to the ketogenic diet. Clinicians are encouraged to consider the ketogenic diet early in the treatment course of patients with Angelman syndrome.
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Affiliation(s)
- Diane Stein
- Pediatric Neurology, Southern California Permanente Medical Group, Kaiser Permanente Hospital Bellflower, Bellflower, CA, USA
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13
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Thibert RL, Conant KD, Braun EK, Bruno P, Said RR, Nespeca MP, Thiele EA. Epilepsy in Angelman syndrome: A questionnaire-based assessment of the natural history and current treatment options. Epilepsia 2009; 50:2369-76. [PMID: 19453717 DOI: 10.1111/j.1528-1167.2009.02108.x] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Ronald L Thibert
- Department of Neurology, Pediatric Epilepsy Program, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
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14
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Andrade DM, Hamani C, Minassian BA. Treatment options for epileptic myoclonus and epilepsy syndromes associated with myoclonus. Expert Opin Pharmacother 2009; 10:1549-60. [PMID: 19527185 DOI: 10.1517/14656560903025189] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Myoclonus is a brief shock-like movement that has many different etiologies. The degree to which it disturbs quality of life is extremely variable, as is its response to treatment. OBJECTIVE In this review, we focus on the treatment strategies for epileptic myoclonus in some common disorders, and in others that are not so common but where myoclonus is a prominent feature and has been studied more. METHODS An extended literature review in the English language was conducted through PubMed and text books. CONCLUSION Epileptic myoclonus is a manifestation of cortical irritability. The precise etiology is important when determining the best course of treatment. Response to treatment is variable and usually depends on the epileptic syndrome. Some antiepileptic drugs may worsen myoclonus even in patients with syndromes where most patients have a good response to that same drug. Therefore, clinicians must always have in mind that worsening in myoclonus may be ameliorated by decrease or withdrawal rather than increase of medication.
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Affiliation(s)
- Danielle M Andrade
- Division of Neurology, Krembil Neuroscience Centre, University of Toronto, Toronto Western Hospital, Toronto, Canada
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García Ramírez M, Csanyi B, Martínez Antón J, Delgado Marqués M, Bauzano Poley E. Síndrome de Angelman: diagnóstico genético y clínico. Revisión de nuestra casuística. An Pediatr (Barc) 2008; 69:232-8. [DOI: 10.1157/13125817] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
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Pelc K, Boyd SG, Cheron G, Dan B. Epilepsy in Angelman syndrome. Seizure 2008; 17:211-7. [PMID: 17904873 DOI: 10.1016/j.seizure.2007.08.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2007] [Accepted: 08/21/2007] [Indexed: 10/22/2022] Open
Abstract
Angelman syndrome is a neurogenetic disorder caused by lack of UBE3A gene expression from the maternally inherited chromosome 15 due to various 15q11-q13 abnormalities. In addition to severe developmental delay, virtual absence of speech, motor impairment, a behavioural phenotype that includes happy demeanor, and distinctive rhythmic electroencephalographic features, over 90% of patients have epilepsy. Many different seizure types may occur, atypical absences and myoclonic seizures being particularly prevalent. Non-convulsive status epilepticus is common, sometimes in the context of the epileptic syndrome referred to as myoclonic status in non-progressive encephalopathies. Epilepsy predominates in childhood, but may persist or reappear in adulthood. Management is difficult in a proportion of patients. It might be improved by better understanding of pathophysiology. Current hypotheses involve abnormal inhibitory transmission due to impaired regulation of GABAA receptors related to functional absence of UBE3A and abnormal hippocampal CaMKII activity.
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Affiliation(s)
- Karine Pelc
- Department of Neurology, Hôpital Universitaire des Enfants Reine Fabiola, Université Libre de Bruxelles, Brussels, Belgium
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Dion MH, Novotny EJ, Carmant L, Cossette P, Nguyen DK. Lamotrigine therapy of epilepsy with Angelman's syndrome. Epilepsia 2007; 48:593-6. [PMID: 17326790 DOI: 10.1111/j.1528-1167.2006.00969.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE Angelman syndrome (AS) is a neurogenetic disorder characterized by developmental delay and a frequently refractory epileptic condition. Valproate, clonazepam and/or phenytoin are said to be the most effective antiepileptic drugs (AEDs) against the seizures in AS. Experience with the newer AEDs is very limited despite their better safety profile and tolerability. Considering its favorable side effect profile and its effectiveness against both partial and generalized seizures, we hypothesized that lamotrigine (LTG) might be more efficacious and better tolerated. METHODS Potential patients for this retrospective study were identified from the epilepsy clinics at Notre-Dame, Sainte-Justine, and Yale New Haven hospitals. Patients were included in the study if they had AS along with refractory seizures. The medical record of each patient was reviewed with interest on seizure types, previous AEDs and response to LTG. RESULTS Five patients (2M, 3F) were included in this study. Age at LTG ranged from 10 to 33 years old. All had >or=2 seizure types, mainly generalized tonic-clonic, myoclonic seizures, and atypical absences. Previously tried AEDs included valproic acid (5), benzodiazepines (5), phenytoin (4), carbamazepine (3), and topiramate (1). One patient had pancreatitis on phenytoin, one had worsened seizures on carbamazepine, and one developed hepatic encephalopathy on valproic acid. Three patients became seizure-free with LTG (9, 20, and 36 months FU), one was seizure-free for 1 year with subsequent loss of efficacy, and one showed >50% reduction in myoclonic seizures (20 months FU). No side effects were reported. CONCLUSION LTG can be efficacious and well tolerated in patients with AS.
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Affiliation(s)
- Marie-Hélène Dion
- Centre Hospitalier Université de Montréal (Hôpital Notre-Dame), Montréal, Canada
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Handforth A, Delorey TM, Homanics GE, Olsen RW. Pharmacologic evidence for abnormal thalamocortical functioning in GABA receptor beta3 subunit-deficient mice, a model of Angelman syndrome. Epilepsia 2006; 46:1860-70. [PMID: 16393151 DOI: 10.1111/j.1528-1167.2005.00287.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE gamma-Aminobutyric acid receptor (GABA(A)r) subunit beta3-deficient mice model Angelman syndrome by displaying impaired learning, abnormal EEG with interictal spikes and slowing, myoclonus, and convulsions. The beta3-subunit deficiency causes a failure of intrathalamic reticular nucleus inhibition, leading to abnormally synchronized thalamocortical oscillations. We postulated that this pathophysiology underlies the abnormal cortical EEG and triggers interictal spikes and seizures, but extrathalamic regions also contribute to interictal spikes and seizures, so that the EEG slowing should reveal an absence-like response profile, whereas spikes and seizures have dual responsiveness to absence and partial-seizure drugs. METHODS Recording electrodes were implanted over the parietal cortices of wild-type, heterozygotes, and homozygous null mice. In each experiment, EEG was recorded for 45 min, either drug or vehicle administered, and EEG recorded for another 3 h. Each EEG was scored for slow-wave activity, interictal spikes, and seizures by a reader blinded to treatments. RESULTS Interictal spiking and percentage of time in EEG slowing in heterozygotes were increased by the proabsence drug baclofen (GABA(B)-receptor agonist), whereas CGP 35348 (GABA(B)-receptor antagonist) had the opposite effect. The antiabsence drug ethosuximide markedly suppressed EEG slowing and interictal spiking in heterozygote and null mice. Broad-spectrum clonazepam and valproate were more effective on interictal spiking than on EEG slowing, and fosphenytoin suppressed only interictal spiking. CONCLUSIONS The results suggest that this model of Angelman syndrome, although not expressing typical absence seizures, is characterized by hypersynchronous thalamocortical oscillations that possess absence-like pharmacologic responsiveness and promote EEG slowing, interictal spikes, and convulsive seizures.
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Affiliation(s)
- Adrian Handforth
- Department of Neurology, VA Greater Los Angeles Health Care System, Los Angeles, CA 90073, USA.
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Guerrini R, Carrozzo R, Rinaldi R, Bonanni P. Angelman syndrome: etiology, clinical features, diagnosis, and management of symptoms. Paediatr Drugs 2004; 5:647-61. [PMID: 14510623 DOI: 10.2165/00148581-200305100-00001] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
It is estimated that Angelman syndrome (AS) accounts for up to 6% of all children presenting with severe mental retardation and epilepsy. The main clinical features of AS may not be apparent early in life. Clinical findings present in all patients include developmental delay, which becomes apparent by 6-12 months of age, severely impaired expressive language, ataxic gait, tremulousness of limbs, and a typical behavioral profile, including a happy demeanor, hypermotoric behavior, and low attention span. Seizures, abnormal electroencephalography, microcephaly, and scoliosis are observed in >80% of patients. Approximately 70% of patients show a deletion involving the maternally inherited chromosome 15q11-q13, encompassing a cluster of gamma-aminobutyric acid receptor subunit genes, 3% show chromosome 15 paternal uniparental disomy (UPD), 1% harbor a mutation in the imprinting center (a transcriptional regulatory element), and 6% harbor intragenic mutations of the ubiquitin-protein ligase E3A (UBE3A) gene. Twenty percent of patients have no detectable genetic abnormality. Rare cases of familial recurrence of AS show either imprinting center (IC) or UBE3A mutations. Approximately 75% of cases are detected through the methylation test, which allows the detection of AS due to deletions, UPD and IC mutations. Mutation analysis of the UBE3A gene should be performed when the methylation test is negative. Individuals with chromosome 15q11-q13 deletions have a more severe clinical picture and are more prone to develop severe epilepsy. Epilepsy has typical features, including absence and myoclonic seizures, and insidious episodes of nonconvulsive or subtle myoclonic status which are easily overlooked as children appear apathetic or in a state of neurologic regression. Tremulousness, present in all patients even when seizures are well controlled or absent, is related to distal cortical myoclonus. Valproic acid (sodium valproate), benzodiazepines, and ethosuximide, in various combinations, are quite effective in treating the typical seizure types. Piracetam may help in reducing distal myoclonus. Carbamazepine and vigabatrin may seriously aggravate absence and myoclonic seizures and should be avoided. Cognitive, language, and orthopedic problems must be addressed with vigorous rehabilitation programs, including early physical therapy, which may help to develop communicative skills and prevent severe scoliosis and subsequent immobility. Where these treatment strategies are applied, individuals with AS may reach an appreciable level of integration, self care, and have a normal life span.
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Affiliation(s)
- Renzo Guerrini
- Epilepsy, Neurophysiology, and Neurogenetics Unit, Institute of Child Neurology and Psychiatry, University of Pisa and IRCCS Fondazione Stella Maris, Pisa, Italy.
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Gidal BE, Privitera MD, Sheth RD, Gilman JT. Vigabatrin: a novel therapy for seizure disorders. Ann Pharmacother 1999; 33:1277-86. [PMID: 10630829 DOI: 10.1345/aph.18376] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
OBJECTIVE To review the pharmacology, pharmacokinetics, efficacy, and adverse effects of vigabatrin and its role in the management of seizure disorders. METHODS A MEDLINE search of English-language literature from January 1993 through January 1999 was conducted using vigabatrin as a search term to identify pertinent studies and review articles. Additional studies were identified from the bibliographies of reviewed literature. The manufacturer provided postmarketing surveillance data. Priority was given to randomized, double-blind, placebo-controlled studies. FINDINGS Vigabatrin is a selective and irreversible inhibitor of gamma-aminobutyric acid transaminase. In controlled clinical trials of vigabatrin add-on therapy in patients with uncontrolled partial seizures, 24-67% of patients achieved a < or =50% reduction in seizure frequency. Data from two comparative trials with carbamazepine monotherapy indicate that vigabatrin monotherapy reduces the frequency of partial seizures in patients with newly diagnosed epilepsy. Vigabatrin also controls infantile spasms, particularly those associated with tuberous sclerosis. Vigabatrin is more effective in patients with partial seizures than in those with generalized seizures. The drug is generally well tolerated. Headache and drowsiness were the most common adverse effects observed in controlled clinical trials; visual field defects, psychiatric reactions, and hyperactivity also have been reported. There are no known clinically significant drug interactions. CONCLUSIONS Vigabatrin improves seizure control as add-on therapy for refractory partial seizures and may produce therapeutic benefits in the treatment of infantile spasms. Vigabatrin is generally well tolerated, with a convenient administration schedule, a lack of known significant drug interactions, and no need for routine monitoring of plasma concentrations.
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Affiliation(s)
- B E Gidal
- School of Pharmacy and Department of Neurology, University of Wisconsin, Madison 53706, USA.
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Millichap JG. Vigabatrin-Induced Seizures in Angelman Syndrome. Pediatr Neurol Briefs 1998. [DOI: 10.15844/pedneurbriefs-12-12-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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