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Amin S, Ruban-Fell B, Newell I, Evans J, Vyas K, Nortvedt C, Chin RF. Treatment guidelines for rare, early-onset conditions associated with epileptic seizures: a literature review on Rett syndrome and tuberous sclerosis complex. Orphanet J Rare Dis 2024; 19:89. [PMID: 38409029 PMCID: PMC10895812 DOI: 10.1186/s13023-023-02994-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 12/13/2023] [Indexed: 02/28/2024] Open
Abstract
BACKGROUND Rett syndrome (RTT) and tuberous sclerosis complex (TSC) are two rare disorders presenting with a range of different epileptic seizures. Seizure management requires careful therapy selection, thereby necessitating development of high-quality treatment guidelines. This targeted literature review (TLR) aimed to characterise country-specific and international treatment guidelines available for pharmacological management of seizures in RTT and TSC. METHODS A TLR was performed between 25-Jan and 11-Mar 2021. Manual searches of online rare disease and guideline databases, and websites of national heath technology assessment bodies were conducted for the following countries: Australia, Canada, France, Germany, Israel, Italy, Japan, Spain, Switzerland, UK, and US as defined by pre-specified eligibility criteria. Search terms were developed for each condition and translated into local languages where appropriate. Eligible publications were defined as guidelines/guidance reporting pharmacological management of seizures in patients with RTT and TSC. Guideline development methodology, geographical focus, author information and treatment recommendations were extracted from guidelines. An author map was generated using R version 3.5.1 to visualise extent of collaboration between authors. RESULTS 24 total guidelines were included, of which three and six contained only recommendations for RTT and TSC, respectively (some provided recommendations for ≥ 1 condition). Guideline development processes were poorly described (50% [12 guidelines] had unclear/absent literature review methodologies); reported methodologies were variable, including systematic literature reviews (SLRs)/TLRs and varying levels of expert consultation. Most (83% [20/24]) were country-specific, with guideline authors predominantly publishing in contained national groups; four guidelines were classified as 'International,' linking author groups in the US, UK, Italy and France. High levels of heterogeneity were observed in the availability of treatment recommendations across indications, with 13 and 67 recommendations found for RTT and TSC, respectively. For RTT, all treatment recommendations were positive and sodium valproate had the highest number of positive recommendations (Khwaja, Sahin (2011) Curr Opin Pediatr 23(6):633-9). All TSC treatments (21 medications) received either exclusively negative (National Organization for Rare Disorders (2019)) or positive (Chu-Shore et al. (2010) Epilepsia 51(7):1236-41) recommendations; vigabatrin received the highest number of positive recommendations (Kaur, Christodoulou (2019)). CONCLUSIONS This review highlights the need for the development of international high-quality and comprehensive consensus-based guidance for the management of seizures with pharmacological therapy in RTT and TSC. TRIAL REGISTRATION Not applicable.
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Affiliation(s)
- S Amin
- Bristol Royal Hospital for Children, Research and Education Centre, Upper Maudlin St, Bristol, BS2 8AE, UK.
| | | | | | - J Evans
- Costello Medical, Cambridge, UK
| | - K Vyas
- GW Pharmaceuticals, London, UK
| | | | - R F Chin
- Royal Hospital for Children and Young People, Edinburgh, UK
- Muir Maxwell Epilepsy Centre, Centre for Clinical Brain Sciences, Edinburgh, UK
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Feria-Romero IA, Reyes-Cuayahuitl A, Sosa-Maldonado J, Montes-Aparicio AV, Rayo-Mares D, Pérez-Pérez D, Grijalva-Otero I, Orozco-Suarez S. Study of genetic variants and their clinical significance in Mexican pediatric patients with epilepsy. Gene 2023:147565. [PMID: 37315635 DOI: 10.1016/j.gene.2023.147565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/06/2023] [Accepted: 06/09/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND The use of novel and accurate techniques to identify genetic variants (with or without a record in the National Center for Biotechnology Information (NCBI) database) improves diagnosis, prognosis, and therapeutics for patients with epilepsy, especially in populations for whom such techniques exist. The aim of this study was to find a genetic profile in Mexican pediatric epilepsy patients by focusing on ten genes associated with drug-resistant epilepsy (DRE). METHODS This was a prospective, analytical, cross-sectional study of pediatric patients with epilepsy. Informed consent was granted by the patients' guardians or parents. Genomic DNA from the patients was sequenced using next-generation sequencing (NGS). For statistical analysis, Fisher's exact, Chi-square or Mann-Whitney U, and OR (95% CI) tests were performed, with significance values of p<0.05. RESULTS Fifty-five patients met the inclusion criteria (female 58.2%, ages 1-16 years); 32 patients had controlled epilepsy (CTR), and 23 had DRE. Four hundred twenty-two genetic variants were identified (71.3% with a known SNP registered in the NCBI database). A dominant genetic profile consisting of four haplotypes of the SCN1A, CYP2C9, and CYP2C19 genes was identified in most of the patients studied. When comparing the results between patients with DRE and CTR, the prevalence of polymorphisms in the SCN1A (rs10497275, rs10198801, and rs67636132), CYP2D6 (rs1065852), and CYP3A4 (rs2242480) genes showed statistical significance (p = 0.021). Finally, the number of missense genetic variants in patients in the nonstructural subgroup was significantly higher in DRE than in CTR (1 [0-2] vs. 3 [2-4]; p=0.014). CONCLUSIONS The Mexican pediatric epilepsy patients included in this cohort presented a characteristic genetic profile infrequent in the Mexican population. SNP rs1065852 (CYP2D6*10) is associated with DRE, especially with nonstructural damage. The presence of three genetic alterations affecting the CYP2B6, CYP2C9, and CYP2D6 cytochrome genes is associated with nonstructural DRE.
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Affiliation(s)
- Iris A Feria-Romero
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Aracely Reyes-Cuayahuitl
- Servicio de Neurología Pediátrica, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | | | - Alexia V Montes-Aparicio
- Programa de Maestría, Escuela Superior de Medicina, Instituto Politécnico Nacional, Ciudad de México, México
| | - Darío Rayo-Mares
- Servicio de Neurología Pediátrica, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Daniel Pérez-Pérez
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilian University, Munich, Germany
| | - Israel Grijalva-Otero
- Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, "Dr. Bernardo Sepúlveda", Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México
| | - Sandra Orozco-Suarez
- Servicio de Neurología Pediátrica, Hospital de Pediatría, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México.
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Reviewing Evidence for the Relationship of EEG Abnormalities and RTT Phenotype Paralleled by Insights from Animal Studies. Int J Mol Sci 2021; 22:ijms22105308. [PMID: 34069993 PMCID: PMC8157853 DOI: 10.3390/ijms22105308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/09/2021] [Accepted: 05/12/2021] [Indexed: 12/29/2022] Open
Abstract
Rett syndrome (RTT) is a rare neurodevelopmental disorder that is usually caused by mutations of the MECP2 gene. Patients with RTT suffer from severe deficits in motor, perceptual and cognitive domains. Electroencephalogram (EEG) has provided useful information to clinicians and scientists, from the very first descriptions of RTT, and yet no reliable neurophysiological biomarkers related to the pathophysiology of the disorder or symptom severity have been identified to date. To identify consistently observed and potentially informative EEG characteristics of RTT pathophysiology, and ascertain areas most worthy of further systematic investigation, here we review the literature for EEG abnormalities reported in patients with RTT and in its disease models. While pointing to some promising potential EEG biomarkers of RTT, our review identify areas of need to realize the potential of EEG including (1) quantitative investigation of promising clinical-EEG observations in RTT, e.g., shift of mu rhythm frequency and EEG during sleep; (2) closer alignment of approaches between patients with RTT and its animal models to strengthen the translational significance of the work (e.g., EEG measurements and behavioral states); (3) establishment of large-scale consortium research, to provide adequate Ns to investigate age and genotype effects.
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Fagiolini M, Patrizi A, LeBlanc J, Jin LW, Maezawa I, Sinnett S, Gray SJ, Molholm S, Foxe JJ, Johnston MV, Naidu S, Blue M, Hossain A, Kadam S, Zhao X, Chang Q, Zhou Z, Zoghbi H. Intellectual and Developmental Disabilities Research Centers: A Multidisciplinary Approach to Understand the Pathogenesis of Methyl-CpG Binding Protein 2-related Disorders. Neuroscience 2020; 445:190-206. [PMID: 32360592 DOI: 10.1016/j.neuroscience.2020.04.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/20/2022]
Abstract
Disruptions in the gene encoding methyl-CpG binding protein 2 (MECP2) underlie complex neurodevelopmental disorders including Rett Syndrome (RTT), MECP2 duplication disorder, intellectual disabilities, and autism. Significant progress has been made on the molecular and cellular basis of MECP2-related disorders providing a new framework for understanding how altered epigenetic landscape can derail the formation and refinement of neuronal circuits in early postnatal life and proper neurological function. This review will summarize selected major findings from the past years and particularly highlight the integrated and multidisciplinary work done at eight NIH-funded Intellectual and Developmental Disabilities Research Centers (IDDRC) across the US. Finally, we will outline a path forward with identification of reliable biomarkers and outcome measures, longitudinal preclinical and clinical studies, reproducibility of results across centers as a synergistic effort to decode and treat the pathogenesis of the complex MeCP2 disorders.
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Affiliation(s)
- Michela Fagiolini
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Annarita Patrizi
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jocelyn LeBlanc
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee-Way Jin
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Izumi Maezawa
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Sarah Sinnett
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sophie Molholm
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - John J Foxe
- The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Michael V Johnston
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Sakkubai Naidu
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Mary Blue
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Ahamed Hossain
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Shilpa Kadam
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Quiang Chang
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Zhaolan Zhou
- Department of Genetic, Epigenetic Institute, University of Pennsylvania Perelman School of Medicine, Intellectual and Developmental Disabilities Research Center, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Huda Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
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Fallah MS, Eubanks JH. Seizures in Mouse Models of Rare Neurodevelopmental Disorders. Neuroscience 2020; 445:50-68. [PMID: 32059984 DOI: 10.1016/j.neuroscience.2020.01.041] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/28/2020] [Accepted: 01/29/2020] [Indexed: 02/07/2023]
Abstract
Genetic neurodevelopmental disorders - that often include epilepsy as part of their phenotype - are a heterogeneous and clinically challenging spectrum of disorders in children. Although seizures often contribute significantly to morbidity in these affected populations, the mechanisms of epileptogenesis in these conditions remain poorly understood. Different model systems have been developed to aid in unraveling these mechanisms, which include a number of specific mutant mouse lines which genocopy specific general types of mutations present in patients. These mouse models have not only allowed for assessments of behavioral and electrographic seizure phenotypes to be ascertained, but also have allowed effects on the neurodevelopmental alterations and cognitive impairments associated with these disorders to be examined. In addition, these models play a role in advancing our understanding of these epileptic processes and developing preclinical therapeutics. The concordance of seizure phenotypes - in a select group of rare, genetic, neurodevelopmental disorders and epileptic encephalopathies - found between human patients and their model counterparts will be summarized. This review aims to assess whether models of Rett syndrome, CDKL5 deficiency disorder, Fragile-X syndrome, Dravet syndrome, and Ohtahara syndrome phenocopy the seizures seen in human patients.
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Affiliation(s)
- Merrick S Fallah
- Division of Experimental and Translational Neuroscience, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario M5T 0S8, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - James H Eubanks
- Division of Experimental and Translational Neuroscience, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario M5T 0S8, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Surgery (Neurosurgery), University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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Jorge-Torres OC, Szczesna K, Roa L, Casal C, Gonzalez-Somermeyer L, Soler M, Velasco CD, Martínez-San Segundo P, Petazzi P, Sáez MA, Delgado-Morales R, Fourcade S, Pujol A, Huertas D, Llobet A, Guil S, Esteller M. Inhibition of Gsk3b Reduces Nfkb1 Signaling and Rescues Synaptic Activity to Improve the Rett Syndrome Phenotype in Mecp2-Knockout Mice. Cell Rep 2019; 23:1665-1677. [PMID: 29742424 DOI: 10.1016/j.celrep.2018.04.010] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2017] [Revised: 02/07/2018] [Accepted: 03/31/2018] [Indexed: 12/01/2022] Open
Abstract
Rett syndrome (RTT) is the second leading cause of mental impairment in girls and is currently untreatable. RTT is caused, in more than 95% of cases, by loss-of-function mutations in the methyl CpG-binding protein 2 gene (MeCP2). We propose here a molecular target involved in RTT: the glycogen synthase kinase-3b (Gsk3b) pathway. Gsk3b activity is deregulated in Mecp2-knockout (KO) mice models, and SB216763, a specific inhibitor, is able to alleviate the clinical symptoms with consequences at the molecular and cellular levels. In vivo, inhibition of Gsk3b prolongs the lifespan of Mecp2-KO mice and reduces motor deficits. At the molecular level, SB216763 rescues dendritic networks and spine density, while inducing changes in the properties of excitatory synapses. Gsk3b inhibition can also decrease the nuclear activity of the Nfkb1 pathway and neuroinflammation. Altogether, our findings indicate that Mecp2 deficiency in the RTT mouse model is partially rescued following treatment with SB216763.
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Affiliation(s)
- Olga C Jorge-Torres
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Karolina Szczesna
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Laura Roa
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Carme Casal
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Louisa Gonzalez-Somermeyer
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Marta Soler
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Cecilia D Velasco
- Laboratory of Neurobiology, Bellvitge Biomedical Research Institute (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Department of Pathology and Experimental Therapeutics, Faculty of Medicine, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Institute of Neurosciences, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain
| | - Pablo Martínez-San Segundo
- Laboratory of Neurobiology, Bellvitge Biomedical Research Institute (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Department of Pathology and Experimental Therapeutics, Faculty of Medicine, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Institute of Neurosciences, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain
| | - Paolo Petazzi
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Mauricio A Sáez
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Raúl Delgado-Morales
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain; Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNs), Maastricht University, Maastricht, the Netherlands
| | - Stephane Fourcade
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain; Institute of Neuropathology, University of Barcelona, Barcelona, Catalonia, Spain; Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain
| | - Aurora Pujol
- Neurometabolic Diseases Laboratory, Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain; Institute of Neuropathology, University of Barcelona, Barcelona, Catalonia, Spain; Center for Biomedical Research on Rare Diseases (CIBERER), ISCIII, Madrid, Spain; Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain
| | - Dori Huertas
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain
| | - Artur Llobet
- Laboratory of Neurobiology, Bellvitge Biomedical Research Institute (IDIBELL), 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Department of Pathology and Experimental Therapeutics, Faculty of Medicine, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain; Institute of Neurosciences, University of Barcelona, 08907 L'Hospitalet de Llobregat, Barcelona, Catalonia, Spain
| | - Sonia Guil
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain.
| | - Manel Esteller
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), 08908 L'Hospitalet, Barcelona, Catalonia, Spain; Institucio Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain; Physiological Sciences Department, School of Medicine and Health Sciences, University of Barcelona (UB), 08907 Catalonia, Spain.
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Zamberletti E, Gabaglio M, Piscitelli F, Brodie JS, Woolley-Roberts M, Barbiero I, Tramarin M, Binelli G, Landsberger N, Kilstrup-Nielsen C, Rubino T, Di Marzo V, Parolaro D. Cannabidivarin completely rescues cognitive deficits and delays neurological and motor defects in male Mecp2 mutant mice. J Psychopharmacol 2019; 33:894-907. [PMID: 31084246 DOI: 10.1177/0269881119844184] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
BACKGROUND Recent evidence suggests that 2-week treatment with the non-psychotomimetic cannabinoid cannabidivarin (CBDV) could be beneficial towards neurological and social deficits in early symptomatic Mecp2 mutant mice, a model of Rett syndrome (RTT). AIM The aim of this study was to provide further insights into the efficacy of CBDV in Mecp2-null mice using a lifelong treatment schedule (from 4 to 9 weeks of age) to evaluate its effect on recognition memory and neurological defects in both early and advanced stages of the phenotype progression. METHODS CBDV 0.2, 2, 20 and 200 mg/kg/day was administered to Mecp2-null mice from 4 to 9 weeks of age. Cognitive and neurological defects were monitored during the whole treatment schedule. Biochemical analyses were carried out in brain lysates from 9-week-old wild-type and knockout mice to evaluate brain-derived neurotrophic factor (BDNF) and insulin-like growth factor-1 (IGF-1) levels as well as components of the endocannabinoid system. RESULTS CBDV rescues recognition memory deficits in Mecp2 mutant mice and delays the appearance of neurological defects. At the biochemical level, it normalizes BDNF/IGF1 levels and the defective PI3K/AKT/mTOR pathway in Mecp2 mutant mice at an advanced stage of the disease. Mecp2 deletion upregulates CB1 and CB2 receptor levels in the brain and these changes are restored after CBDV treatment. CONCLUSIONS CBDV administration exerts an enduring rescue of memory deficits in Mecp2 mutant mice, an effect that is associated with the normalization of BDNF, IGF-1 and rpS6 phosphorylation levels as well as CB1 and CB2 receptor expression. CBDV delays neurological defects but this effect is only transient.
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Affiliation(s)
- Erica Zamberletti
- 1 Department of Biotechnology and Life Sciences (DBSV), University of Insubria, Varese, Italy
| | - Marina Gabaglio
- 1 Department of Biotechnology and Life Sciences (DBSV), University of Insubria, Varese, Italy
| | - Fabiana Piscitelli
- 2 Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Pozzuoli, Naples, Italy
| | | | | | - Isabella Barbiero
- 1 Department of Biotechnology and Life Sciences (DBSV), University of Insubria, Varese, Italy
| | - Marco Tramarin
- 1 Department of Biotechnology and Life Sciences (DBSV), University of Insubria, Varese, Italy
| | - Giorgio Binelli
- 1 Department of Biotechnology and Life Sciences (DBSV), University of Insubria, Varese, Italy
| | - Nicoletta Landsberger
- 4 Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | | | - Tiziana Rubino
- 1 Department of Biotechnology and Life Sciences (DBSV), University of Insubria, Varese, Italy
| | - Vincenzo Di Marzo
- 2 Institute of Biomolecular Chemistry, Consiglio Nazionale delle Ricerche, Pozzuoli, Naples, Italy
| | - Daniela Parolaro
- 1 Department of Biotechnology and Life Sciences (DBSV), University of Insubria, Varese, Italy.,5 Zardi Gori Foundation, Milan, Italy
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8
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Persico AM, Ricciardello A, Cucinotta F. The psychopharmacology of autism spectrum disorder and Rett syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2019; 165:391-414. [DOI: 10.1016/b978-0-444-64012-3.00024-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Wither RG, Colic S, Bardakjian BL, Snead OC, Zhang L, Eubanks JH. Electrographic and pharmacological characterization of a progressive epilepsy phenotype in female MeCP2-deficient mice. Epilepsy Res 2018; 140:177-183. [PMID: 29414525 DOI: 10.1016/j.eplepsyres.2018.01.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 01/05/2018] [Accepted: 01/11/2018] [Indexed: 11/27/2022]
Abstract
Rett Syndrome is a neurodevelopmental disorder caused primarily by mutations in the gene encoding Methyl-CpG-binding protein 2 (MECP2). Spontaneous epileptiform activity is a common co-morbidity present in Rett syndrome, and hyper-excitable neural networks are present in MeCP2-deficient mouse models of Rett syndrome. In this study we conducted a longitudinal assessment of spontaneous cortical electrographic discharges in female MeCP2-deficient mice and defined the pharmacological responsiveness of these discharges to anti-convulsant drugs. Our data show that cortical discharge activity in female MeCP2-deficient mice progressively increases in severity as the mice age, with discharges being more frequent and of longer durations at 19-24 months of age compared to 3 months of age. Semiologically and pharmacologically, this basal discharge activity in female MeCP2-deficient mice displayed electroclinical properties consistent with absence epilepsy. Only rarely were convulsive seizures observed in these mice at any age. Since absence epilepsy is infrequently observed in Rett syndrome patients, these results indicate that the predominant spontaneous electroclinical phenotype of MeCP2-deficient mice we examined does not faithfully recapitulate the most prevalent seizure types observed in affected patients.
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Affiliation(s)
- Robert G Wither
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Sinisa Colic
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Berj L Bardakjian
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - O Carter Snead
- Department of Medicine (Neurology), University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Liang Zhang
- Division of Fundamental Neurobiology, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada; University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Medicine (Neurology), University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - James H Eubanks
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada; University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Surgery (Neurosurgery), University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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10
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Chin Wong L, Hung PL, Jan TY, Lee WT. Variations of stereotypies in individuals with Rett syndrome: A nationwide cross-sectional study in Taiwan. Autism Res 2017; 10:1204-1214. [PMID: 28272783 DOI: 10.1002/aur.1774] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Revised: 01/18/2017] [Accepted: 02/06/2017] [Indexed: 01/04/2023]
Abstract
Individuals with Rett syndrome (RTT) can have variable manifestations of stereotypies. In this nation-wide cross-sectional study, we recruited all individuals with RTT in Taiwan diagnosed as RTT by neurologists based on genetic findings and diagnostic criteria. The data were collected using questionnaire. A total 43 cases of typical RTT and 15 cases of atypical RTT, aged from 2.1 to 40.1 years, were enrolled. They included 3 (5.2%) in stage II, 42 (72.4%) in stage III, and 13 (22.4%) in stage IV. All individuals presented with at least one stereotypy. Individuals with atypical RTT had more varied stereotypies (mean: 14 ± 6) compared to those with typical RTT (mean: 9 ± 5) (P = 0.003). Flapping (73.3%) and wringing (58.1%) were the most common hand stereotypies in atypical and typical RTT, respectively. Compared with typical RTT, hair pulling, bruxism, retropulsion, and protrusion of lips were more common in atypical RTT (P = 0.003, P = 0.006, P = 0.003 and <0.001, respectively). The number of stereotypies did not differ among different stages, clinical severities, and hand functions. Although there were no age-related changes in stereotypies in atypical RTT, flapping (P = 0.012), clapping (P = 0.044), and mouthing with single hand (P = 0.009) were significantly more prevalent in individuals aged <10 years with typical RTT, and they decreased after 10 years. In conclusion, our study showed that the stereotypical movements varied in typical and atypical RTT, implying the heterogeneous nature of the disease and the pathogenic mechanisms of RTT with atypical features. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1204-1214. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
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Affiliation(s)
- Lee Chin Wong
- Department of Pediatrics, Min-Sheng General Hospital, Min-Sheng Hospital 168, ChingKuo Road, Taoyuan, 330, Taiwan.,Department of Pediatric Neurology, National Taiwan University Children's Hospital, No8, Chung-Shan South Road, Zhong-Zheng District, Taipei, 100, Taiwan
| | - Pi-Lien Hung
- Department of Pediatrics, Kaohsiung Chang Gung Memorial Hospital, No.123,DAPI Road, Niaosng District, Kaohsiung, 83301, Taiwan
| | - Tz-Yun Jan
- Graduate Institute of Brain and Mind Sciences, National Taiwan University, No.1, Sec.1, Ren-Ai Road, Taipei, 100, Taiwan
| | - Wang-Tso Lee
- Department of Pediatric Neurology, National Taiwan University Children's Hospital, No8, Chung-Shan South Road, Zhong-Zheng District, Taipei, 100, Taiwan
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11
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Vignoli A, Savini MN, Nowbut MS, Peron A, Turner K, La Briola F, Canevini MP. Effectiveness and tolerability of antiepileptic drugs in 104 girls with Rett syndrome. Epilepsy Behav 2017; 66:27-33. [PMID: 27988477 DOI: 10.1016/j.yebeh.2016.10.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 10/06/2016] [Accepted: 10/08/2016] [Indexed: 11/30/2022]
Abstract
UNLABELLED Approximately 60-80% of girls with Rett Syndrome (RTT) have epilepsy, which represents one of the most severe problems clinicians have to deal with, especially when patients are 7-12years old. The aim of this study was to analyze the antiepileptic drugs (AEDs) prescribed in RTT, and to assess their effectiveness and tolerability in different age groups from early infancy to adulthood. We included in this study 104 girls, aged 2-42years (mean age 13.9years): 89 had a mutation in MECP2, 5 in CDKL5, 2 in FOXG1, and the mutational status was unknown in the remaining 8. Epilepsy was present in 82 patients (79%). Mean age at epilepsy onset was 4.1years. We divided the girls into 5 groups according to age: <5, 5-9, 10-14, 15-19, 20years and older. Valproic acid (VPA) was the most prescribed single therapy in young patients (<15years), whereas carbamazepine (CBZ) was preferred by clinicians in older patients. The most frequently adopted AED combination in the patients younger than 10years and older than 15 was VPA and lamotrigine (LTG). Seizures in the group aged 10-14years were the most difficult to treat, requiring a mean of three different AEDs, often used in combination and mostly including VPA. Seizures in fifteen patients (18%) were considered drug resistant. VPA was reported as the most effective AED in younger girls (in 40% of the patients aged <5years, in 19% of the girls aged 5-9years), and CBZ the most effective in the patients 15years or older. Adverse reactions did not differ from expected: agitation, drowsiness, and weight loss were the most frequently reported. In our sample, LTG was the least tolerated AED. We did not find correlations with MECP2 mutations in terms of effectiveness or adverse reactions. CONCLUSION in this study we observed different effectiveness of AEDs based on age, and suggest that clinicians consider age-dependency when prescribing appropriate AEDs in the RTT population.
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Affiliation(s)
- Aglaia Vignoli
- Epilepsy Center, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Italy
| | - Miriam Nella Savini
- Epilepsy Center, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Italy.
| | - Maria Sonia Nowbut
- Epilepsy Center, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Italy
| | - Angela Peron
- Epilepsy Center, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Italy
| | - Katherine Turner
- Epilepsy Center, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Italy
| | - Francesca La Briola
- Epilepsy Center, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Italy
| | - Maria Paola Canevini
- Epilepsy Center, San Paolo Hospital, Department of Health Sciences, Università degli Studi di Milano, Italy
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12
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Colic S, Wither RG, Lang M, Zhang L, Eubanks JH, Bardakjian BL. Prediction of antiepileptic drug treatment outcomes using machine learning. J Neural Eng 2016; 14:016002. [PMID: 27900948 DOI: 10.1088/1741-2560/14/1/016002] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Antiepileptic drug (AED) treatments produce inconsistent outcomes, often necessitating patients to go through several drug trials until a successful treatment can be found. This study proposes the use of machine learning techniques to predict epilepsy treatment outcomes of commonly used AEDs. APPROACH Machine learning algorithms were trained and evaluated using features obtained from intracranial electroencephalogram (iEEG) recordings of the epileptiform discharges observed in Mecp2-deficient mouse model of the Rett Syndrome. Previous work have linked the presence of cross-frequency coupling (I CFC) of the delta (2-5 Hz) rhythm with the fast ripple (400-600 Hz) rhythm in epileptiform discharges. Using the I CFC to label post-treatment outcomes we compared support vector machines (SVMs) and random forest (RF) machine learning classifiers for providing likelihood scores of successful treatment outcomes. MAIN RESULTS (a) There was heterogeneity in AED treatment outcomes, (b) machine learning techniques could be used to rank the efficacy of AEDs by estimating likelihood scores for successful treatment outcome, (c) I CFC features yielded the most effective a priori identification of appropriate AED treatment, and (d) both classifiers performed comparably. SIGNIFICANCE Machine learning approaches yielded predictions of successful drug treatment outcomes which in turn could reduce the burdens of drug trials and lead to substantial improvements in patient quality of life.
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Affiliation(s)
- Sinisa Colic
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, ON M5S-3G4, Canada
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13
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The role of transcranial magnetic stimulation in evaluation of motor cortex excitability in Rett syndrome. Eur J Paediatr Neurol 2016; 20:597-603. [PMID: 27131828 DOI: 10.1016/j.ejpn.2016.03.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 03/16/2016] [Accepted: 03/30/2016] [Indexed: 01/18/2023]
Abstract
UNLABELLED Rett syndrome (RTT) is a frequent neurodevelopmental disorder confirmed by clinical criteria and supported by the methyl-CpG-binding protein 2 gene (MECP2) mutation. A short central motor conduction time (CMCT) was reported in transcranial magnetic stimulation (TMS) studies performed in RTT. This was attributed to hyperexcitability of the motor cortex and/or spinal motor neurons, but was not studied further. AIM We performed TMS in RTT to evaluate motor cortex excitability by determining the cortical motor threshold (CMT) and motor cortex inhibition by the cortical silent period (CSP) besides measuring CMCT. METHODS Single-pulse TMS was performed in 17 Rett patients, diagnosed by clinical criteria and MECP2 mutation testing, and the same number of healthy controls. The outcome measures were compared between RTT groups with different antiepileptic drugs (AED) and those with and without the MECP2 mutation. RESULTS CMCT was shorter, but we found elevated CMT and shorter CSP, which suggests decreased excitatory and inhibitory motor cortical function. The outcome was independent of AED and the presence or absence of the MECP2 mutation. INTERPRETATION Decreased excitatory and inhibitory motor cortical function could explain the short CMCT, with higher stimulus intensities needed to excite pyramidal neurons.
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14
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Zhang L, Wither RG, Lang M, Wu C, Sidorova-Darmos E, Netchev H, Matolcsy CB, Snead OC, Eubanks JH. A Role for Diminished GABA Transporter Activity in the Cortical Discharge Phenotype of MeCP2-Deficient Mice. Neuropsychopharmacology 2016; 41:1467-76. [PMID: 26499511 PMCID: PMC4832024 DOI: 10.1038/npp.2015.323] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Revised: 09/13/2015] [Accepted: 10/01/2015] [Indexed: 12/14/2022]
Abstract
Cortical network hyper-excitability is a common phenotype in mouse models lacking the transcriptional regulator methyl-CPG-binding protein 2 (MeCP2). Here, we implicate enhanced GABAB receptor activity stemming from diminished cortical expression of the GABA transporter GAT-1 in the genesis of this network hyper-excitability. We found that administering the activity-dependent GABAB receptor allosteric modulator GS-39783 to female Mecp2(+/-) mice at doses producing no effect in wild-type mice strongly potentiated their basal rates of spontaneous cortical discharge activity. Consistently, administering the GABAB receptor antagonist CGP-35348 significantly decreased basal discharge activity in these mice. Expression analysis revealed that while GABAB or extra-synaptic GABAA receptor prevalence is preserved in the MeCP2-deficient cortex, the expression of GAT-1 is significantly reduced from wild-type levels. This decrease in GAT-1 expression is consequential, as low doses of the GAT-1 inhibitor NO-711 that had no effects in wild-type mice strongly exacerbated cortical discharge activity in female Mecp2(+/-) mice. Taken together, these data indicate that the absence of MeCP2 leads to decreased cortical levels of the GAT-1 GABA transporter, which facilitates cortical network hyper-excitability in MeCP2-deficient mice by increasing the activity of cortical GABAB receptors.
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Affiliation(s)
- Liang Zhang
- Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,University of Toronto Epilepsy Research Program, University of Toronto, Toronto, ON, Canada,Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada
| | - Robert G Wither
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Min Lang
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, ON, Canada,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Chiping Wu
- Division of Fundamental Neurobiology, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
| | - Elena Sidorova-Darmos
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Hristo Netchev
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
| | - Catherine B Matolcsy
- Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada
| | - Orlando Carter Snead
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, ON, Canada,Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada
| | - James H Eubanks
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, ON, Canada,Division of Genetics and Development, Toronto Western Research Institute, University Health Network, Toronto, ON, Canada,Department of Physiology, University of Toronto, Toronto, ON, Canada,Department of Surgery (Neurosurgery), University of Toronto, Toronto, ON, Canada,Toronto Western Hospital, 8KD-417, 60 Leonard Avenue, Toronto, ON M5T 2S8, Canada, Tel: +1 416 603 5800, ext. 2933, Fax: +1 416 603 5745, E-mail:
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15
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Colic S, Wither RG, Eubanks JH, Bardakjian BL. Support vector machines using EEG features of cross-frequency coupling can predict treatment outcome in Mecp2-deficient mice. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2015:5606-9. [PMID: 26737563 DOI: 10.1109/embc.2015.7319663] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Anti-convulsive drug treatments of epilepsy typically produce varied outcomes from one patient to the next, often necessitating patients to go through several anticonvulsive drug trials until an appropriate treatment is found. The focus of this study is to predict treatment outcome using a priori electroencephalogram (EEG) features for a rare genetic model of epilepsy seen in patients with Rett Syndrome. Previous work on Mecp2-deficient mice, exhibiting the symptoms of Rett syndrome, have revealed EEG-based biomarkers that track the pathology well. Specifically the presence of cross-frequency coupling of the delta-like (3-6 Hz) frequency range phase with the fast ripple (400 - 600 Hz) frequency range amplitude in long duration discharges was found to track seizure pathology. Support Vector Machines (SVM) were trained with features generated from phase-amplitude comodulograms and tested on (n=6) Mecp2-deficient mice to predict treatment outcome to Midazolam, a commonly used anti-convulsive drug. Using SVMs it was shown that it is possible to generate a likelihood score to predict treatment outcomes on all of the animal subjects. Identifying the most appropriate treatment a priori would potentially lead to improved treatment outcomes.
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16
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Filosa S, Pecorelli A, D'Esposito M, Valacchi G, Hajek J. Exploring the possible link between MeCP2 and oxidative stress in Rett syndrome. Free Radic Biol Med 2015; 88:81-90. [PMID: 25960047 DOI: 10.1016/j.freeradbiomed.2015.04.019] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 04/10/2015] [Accepted: 04/13/2015] [Indexed: 01/27/2023]
Abstract
Rett syndrome (RTT, MIM 312750) is a rare and orphan progressive neurodevelopmental disorder affecting girls almost exclusively, with a frequency of 1/15,000 live births of girls. The disease is characterized by a period of 6 to 18 months of apparently normal neurodevelopment, followed by early neurological regression, with a progressive loss of acquired cognitive, social, and motor skills. RTT is known to be caused in 95% of the cases by sporadic de novo loss-of-function mutations in the X-linked methyl-CpG-binding protein 2 (MECP2) gene encoding methyl-CpG binding protein 2 (MeCP2), a nuclear protein able to regulate gene expression. Despite almost two decades of research into the functions and role of MeCP2, little is known about the mechanisms leading from MECP2 mutation to the disease. Oxidative stress (OS) is involved in the pathogenic mechanisms of several neurodevelopmental and neurodegenerative disorders, although in many cases it is not clear whether OS is a cause or a consequence of the pathology. Fairly recently, the presence of a systemic OS has been demonstrated in RTT patients with a strong correlation with the patients' clinical status. The link between MECP2 mutation and the redox imbalance found in RTT is not clear. Animal studies have suggested a possible direct correlation between Mecp2 mutation and increased OS levels. In addition, the restoration of Mecp2 function in astrocytes significantly improves the developmental outcome of Mecp2-null mice and reexpression of Mecp2 gene in the brain of null mice restored oxidative damage, suggesting that Mecp2 loss of function can be involved in oxidative brain damage. Starting from the evidence that oxidative damage in the brain of Mecp2-null mice precedes the onset of symptoms, we evaluated whether, based on the current literature, the dysfunctions described in RTT could be a consequence or, in contrast, could be caused by OS. We also analyzed whether therapies that at least partially treated some RTT symptoms can play a role in defense against OS. At this stage we can propose that OS could be one of the main causes of the dysfunctions observed in RTT. In addition, the major part of the therapies recommended to alleviate RTT symptoms have been shown to interfere with oxidative homeostasis, suggesting that MeCP2 could somehow be involved in the protection of the brain from OS.
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Affiliation(s)
- Stefania Filosa
- Institute of Biosciences and BioResources-CNR, UOS Naples, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Alessandra Pecorelli
- Child Neuropsychiatry Unit, University General Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Maurizio D'Esposito
- Institute of Genetics and Biophysics "A. Buzzati-Traverso"-CNR, Naples, Italy; IRCCS Neuromed, Pozzilli, Italy
| | - Giuseppe Valacchi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy; Department of Food and Nutrition, Kyung Hee University, Seoul, South Korea.
| | - Joussef Hajek
- Child Neuropsychiatry Unit, University General Hospital, Azienda Ospedaliera Universitaria Senese, Siena, Italy
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17
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Pintaudi M, Calevo MG, Vignoli A, Baglietto MG, Hayek Y, Traverso M, Giacomini T, Giordano L, Renieri A, Russo S, Canevini M, Veneselli E. Antiepileptic drugs in Rett Syndrome. Eur J Paediatr Neurol 2015; 19:446-52. [PMID: 25814391 DOI: 10.1016/j.ejpn.2015.02.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Revised: 01/03/2015] [Accepted: 02/21/2015] [Indexed: 11/19/2022]
Abstract
PURPOSE We investigated drugs most often used to treat epilepsy in Rett Syndrome and their efficacy in a large cohort of Italian patients. METHODS This is a multi-centre retrospective study. Data of 165 Rett subjects were collected from the patients' files, and hospital charts. The efficacy of antiepileptic drugs (AEDs) was classified as follows: not effective; decrease in seizure frequency ≥50% for at least 6 months; seizure-free for at least 2 years. Phenotypic and genetic categorization of patients was performed and it was considered in AEDs efficacy evaluation. RESULTS There were 130 epileptic patients.Sodium valproate (VPA) was the most commonly administered AED (44.3%) at seizure onset, followed by Carbamazepine (CBZ) (25.4%) and Phenobarbital (PB) (13%). Monotherapy was the first treatment option in most patients. VPA and CBZ proved to be equally effective in Rett patients who presented seizures within the typical age range (4-5 years), while Lamotrigine (LTG) was effective for patients in whom epilepsy started later. Overall, the frequency of side effects was low and the most often observed ones were restlessness and somnolence. CONCLUSION Our study suggests that LTG, VPA and CBZ can be used as drugs of first choice in Rett Syndrome. The association of four drugs should be avoided since it did not result in any significant clinical improvement.
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Affiliation(s)
| | - Maria Grazia Calevo
- Epidemiology and Biostatistics Unit, Istituto Giannina Gaslini, Genoa, Italy
| | - Aglaia Vignoli
- Department of Health Science, Epilepsy Centre, St. Paolo Hospital, University of Milan, Italy
| | - Maria Giuseppina Baglietto
- University of Genoa, DINOGMI, Italy; Department of Child Neuropsychiatry, Epilepsy Centre, Giannina Gaslini Institute, Italy
| | - Yussef Hayek
- Pediatric Neuropsychiatric Unit, University Hospital, Policlinico Le Scotte, Siena, Italy
| | - Maria Traverso
- University of Genoa, DINOGMI, Italy; Department of Child Neuropsychiatry, Epilepsy Centre, Giannina Gaslini Institute, Italy
| | - Thea Giacomini
- University of Genoa, DINOGMI, Italy; Department of Child Neuropsychiatry, Epilepsy Centre, Giannina Gaslini Institute, Italy
| | - Lucio Giordano
- Pediatric Neuropsychiatric Division, City Hospital of Brescia, Brescia, Italy
| | - Alessandra Renieri
- Medical Genetics, University of Siena, Siena, Italy; Genetica Medica, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | - Silvia Russo
- Department of Genetics, Istituto Auxologico Italiano, IRCCS, Milan, Italy
| | - MariaPaola Canevini
- Department of Health Science, Epilepsy Centre, St. Paolo Hospital, University of Milan, Italy
| | - Edvige Veneselli
- University of Genoa, DINOGMI, Italy; Department of Child Neuropsychiatry, Epilepsy Centre, Giannina Gaslini Institute, Italy
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18
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Krajnc N. Management of epilepsy in patients with Rett syndrome: perspectives and considerations. Ther Clin Risk Manag 2015; 11:925-32. [PMID: 26089674 PMCID: PMC4468994 DOI: 10.2147/tcrm.s55896] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Rett syndrome (RTT) is a common neurodevelopmental disorder that appears in infancy with regression of acquired motor skills, loss of purposeful activity, hand stereotypies, loss of acquired spoken language, and seizures. Epilepsy affects the majority of patients in a specific clinical stage of the disease and is drug resistant in approximately one-third of cases. The association of epilepsy and even drug-resistant epilepsy has been reported in certain genotypes of the methyl-CpG-binding protein 2 mutation, which is present in a majority of patients with classical RTT. The evolution of electroencephalographic abnormalities accompanying the clinical development of the syndrome is well described, but much less is known about the seizure semiology and the effectiveness of specific antiepileptic drugs. The aim of this review is to present the clinical and electrophysiological aspects of epilepsy in RTT and the current treatment approach.
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Affiliation(s)
- Natalija Krajnc
- Department of Child, Adolescent and Developmental Neurology, University Children's Hospital, Ljubljana, Slovenia
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19
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Nissenkorn A, Levy-Drummer RS, Bondi O, Renieri A, Villard L, Mari F, Mencarelli MA, Lo Rizzo C, Meloni I, Pineda M, Armstrong J, Clarke A, Bahi-Buisson N, Mejaski BV, Djuric M, Craiu D, Djukic A, Pini G, Bisgaard AM, Melegh B, Vignoli A, Russo S, Anghelescu C, Veneselli E, Hayek J, Ben-Zeev B. Epilepsy in Rett syndrome--lessons from the Rett networked database. Epilepsia 2015; 56:569-76. [PMID: 25789914 DOI: 10.1111/epi.12941] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/14/2015] [Indexed: 12/21/2022]
Abstract
OBJECTIVE Rett syndrome is an X-linked dominant neurodevelopmental disorder caused by mutations in the MECP2 gene, and characterized by cognitive and communicative regression, loss of hand use, and midline hand stereotypies. Epilepsy is a core symptom, but literature is controversial regarding genotype-phenotype correlation. Analysis of data from a large cohort should overcome this shortcoming. METHODS Data from the Rett Syndrome Networked Database on 1,248 female patients were included. Data on phenotypic and genotypic parameters, age of onset, severity of epilepsy, and type of seizures were collected. Statistical analysis was done using the IBM SPSS Version 21 software, logistic regression, and Kaplan-Meier survival curves. RESULTS Epilepsy was present in 68.1% of the patients, with uncontrolled seizures in 32.6% of the patients with epilepsy. Mean age of onset of epilepsy was 4.68 ± (standard deviation) 3.5 years. Younger age of onset was correlated to severity of epilepsy (Spearman correlation r = 0.668, p < 0.01). Patients with late truncating deletions had lower prevalence of epilepsy. Compared to them, the p.R133C mutation, associated with a milder Rett phenotype, increased the risk for epilepsy (odds ratio [OR] 2.46, confidence interval [CI] 95% 1.3-4.66), but not for severe epilepsy. The p.R255X mutation conferred an increased risk for epilepsy (OR 2.07, CI 95% 1.2-3.59) as well as for severe epilepsy (OR 3.4, CI 95% 1.6-7.3). The p.T158M and p.C306C mutations relatively increased the risk for severe epilepsy (OR 3.09 and 2.69, CI 95% 1.48-6.4 and 1.19-6.05, respectively), but not for epilepsy occurrence. SIGNIFICANCE Various mutations in the MECP2 gene have a different influence on epilepsy, unrelated to the severity of the general Rett phenotype. This might suggest a site-specific effect of MeCp2 on epileptic pathways. Further investigation of these mechanisms should promote better understanding of epileptogenesis in Rett syndrome.
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Affiliation(s)
- Andreea Nissenkorn
- Pediatric Neurology Unit and Rett National Center, Edmond and Lily Safra Children's Hospital, Sheba Medical Center, Tel HaShomer, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
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20
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Guo W, Tsujimura K, Otsuka I M, Irie K, Igarashi K, Nakashima K, Zhao X. VPA alleviates neurological deficits and restores gene expression in a mouse model of Rett syndrome. PLoS One 2014; 9:e100215. [PMID: 24968028 PMCID: PMC4072629 DOI: 10.1371/journal.pone.0100215] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 05/23/2014] [Indexed: 11/23/2022] Open
Abstract
Rett syndrome (RTT) is a devastating neurodevelopmental disorder that occurs once in every 10,000–15,000 live female births. Despite intensive research, no effective cure is yet available. Valproic acid (VPA) has been used widely to treat mood disorder, epilepsy, and a growing number of other disorders. In limited clinical studies, VPA has also been used to control seizure in RTT patients with promising albeit somewhat unclear efficacy. In this study we tested the effect of VPA on the neurological symptoms of RTT and discovered that short-term VPA treatment during the symptomatic period could reduce neurological symptoms in RTT mice. We found that VPA restores the expression of a subset of genes in RTT mouse brains, and these genes clustered in neurological disease and developmental disorder networks. Our data suggest that VPA could be used as a drug to alleviate RTT symptoms.
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Affiliation(s)
- Weixiang Guo
- Department of Neuroscience and Waisman Center, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Keita Tsujimura
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Maky Otsuka I
- Life Science Tokyo Advanced Research center (L-StaR), Hoshi University School of Pharmacy and Pharmaceutical Science, Tokyo, Japan
| | - Koichiro Irie
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Katsuhide Igarashi
- Life Science Tokyo Advanced Research center (L-StaR), Hoshi University School of Pharmacy and Pharmaceutical Science, Tokyo, Japan
| | - Kinichi Nakashima
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Xinyu Zhao
- Department of Neuroscience and Waisman Center, School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, United States of America
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21
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Dolce A, Ben-Zeev B, Naidu S, Kossoff EH. Rett syndrome and epilepsy: an update for child neurologists. Pediatr Neurol 2013; 48:337-45. [PMID: 23583050 DOI: 10.1016/j.pediatrneurol.2012.11.001] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Accepted: 11/12/2012] [Indexed: 01/01/2023]
Abstract
Rett syndrome, a neurogenetic disorder predominantly affecting females, has many characteristic features including psychomotor retardation, impaired language development, hand stereotypies, gait dysfunction, and acquired microcephaly. Although each of these features undoubtedly contributes to the morbidity of this neurologic disorder, epilepsy is perhaps one of the most well-described and problematic, affecting as many as 50%-90% of patients. Seizures can often be refractory, requiring polytherapy and consideration of nonpharmacologic management (e.g., ketogenic diets and vagus nerve stimulation). In addition, many nonepileptic symptoms of Rett syndrome can occasionally be difficult to differentiate from seizures making clinical management and family counseling challenging. Our goal in this review is to better define the clinical and electrophysiological aspects of the epilepsy associated with Rett syndrome and provide practical guidance regarding management.
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Affiliation(s)
- Alison Dolce
- Johns Hopkins Hospital, Baltimore, Maryland, USA.
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22
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Durand S, Patrizi A, Quast KB, Hachigian L, Pavlyuk R, Saxena A, Carninci P, Hensch TK, Fagiolini M. NMDA receptor regulation prevents regression of visual cortical function in the absence of Mecp2. Neuron 2013; 76:1078-90. [PMID: 23259945 DOI: 10.1016/j.neuron.2012.12.004] [Citation(s) in RCA: 115] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/03/2012] [Indexed: 10/27/2022]
Abstract
Brain function is shaped by postnatal experience and vulnerable to disruption of Methyl-CpG-binding protein, Mecp2, in multiple neurodevelopmental disorders. How Mecp2 contributes to the experience-dependent refinement of specific cortical circuits and their impairment remains unknown. We analyzed vision in gene-targeted mice and observed an initial normal development in the absence of Mecp2. Visual acuity then rapidly regressed after postnatal day P35-40 and cortical circuits largely fell silent by P55-60. Enhanced inhibitory gating and an excess of parvalbumin-positive, perisomatic input preceded the loss of vision. Both cortical function and inhibitory hyperconnectivity were strikingly rescued independent of Mecp2 by early sensory deprivation or genetic deletion of the excitatory NMDA receptor subunit, NR2A. Thus, vision is a sensitive biomarker of progressive cortical dysfunction and may guide novel, circuit-based therapies for Mecp2 deficiency.
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Affiliation(s)
- Severine Durand
- FM Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
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23
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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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24
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d'Orsi G, Trivisano M, Luisi C, Demaio V, Di Claudio MT, Pascarella MG, Sciruicchio V, Galeone D, La Neve A, Scarpelli F, Calvario T, Minervini M, La Selva L, Specchio LM. Epileptic seizures, movement disorders, and breathing disturbances in Rett syndrome: diagnostic relevance of video-polygraphy. Epilepsy Behav 2012; 25:401-7. [PMID: 23103540 DOI: 10.1016/j.yebeh.2012.08.033] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/11/2012] [Revised: 07/31/2012] [Accepted: 08/28/2012] [Indexed: 11/28/2022]
Abstract
Epileptic seizures, movement disorders and breathing disturbances may be observed in Rett syndrome, and correct diagnosis is mandatory for the management. We evaluated the usefulness of video-polygraphy in the differential diagnosis between epileptic and non-epileptic paroxysmal events in eight patients with Rett syndrome. Based on video analysis, myoclonic seizures were usually misdiagnosed as movement disorders and stereotypies; the events identified by parents as generalized tonic-clonic seizures included episodes of motor activity and breathing abnormality. Myoclonic seizures aggravated by inappropriate treatment were evident in four patients; hyperventilation and apnea during wakefulness were present in all patients, while central sleep apneas were present in one patient; sinus tachycardia and cardiac arrhythmias emerged in six patients; cortical myoclonus was disclosed in five patients. In Rett syndrome, video-polygraphy is essential in characterizing the clinical features of paroxysmal events, determining autonomic dysfunctions, documenting myoclonic motor phenomena, and evaluating the responses to the treatment of epilepsy.
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Affiliation(s)
- Giuseppe d'Orsi
- Epilepsy Center, Clinic of Nervous System Diseases, University of Foggia, Riuniti Hospital, Foggia, Italy.
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25
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Swiderska N, Hawcutt D, Eaton V, Stockton F, Kumar R, Kneen R, Appleton R. Sulthiame in refractory paediatric epilepsies: An experience of an ‘old’ antiepileptic drug in a tertiary paediatric neurology unit. Seizure 2011; 20:805-8. [DOI: 10.1016/j.seizure.2011.08.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2011] [Revised: 08/07/2011] [Accepted: 08/09/2011] [Indexed: 10/17/2022] Open
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Abstract
Rett syndrome is a neurodevelopmental disorder predominately affecting females. The majority of patients have epilepsy in the early stages of the disease. This study evaluates the clinical course of epilepsy and the effect of antiepileptic drug treatment in Rett syndrome using retrospective data analysis. Epilepsy was present in 16 of 19 (84%) patients with Rett syndrome in this series. The mean age of seizure onset was 4 years. Remission of seizures was achieved after the first monotherapy in 56% and after the second monotherapy in 18.5% of patients. Valproate, lamotrigine, and carbamazepine were the drugs used most frequently as monotherapy. Valproate monotherapy was highly effective as 75% of treated patients achieved seizure remission. Monotherapy with lamotrigine or carbamazepine was effective in half of the treated patients. There was a clear tendency toward seizure remission after the age of 15 years.
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Affiliation(s)
- Natalija Krajnc
- University Children's Hospital, Department of Child, Adolescent and Developmental Neurology, Ljubljana, Slovenia.
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27
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Calfa G, Hablitz JJ, Pozzo-Miller L. Network hyperexcitability in hippocampal slices from Mecp2 mutant mice revealed by voltage-sensitive dye imaging. J Neurophysiol 2011; 105:1768-84. [PMID: 21307327 PMCID: PMC3075283 DOI: 10.1152/jn.00800.2010] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Accepted: 02/03/2011] [Indexed: 11/22/2022] Open
Abstract
Dysfunctions of neuronal and network excitability have emerged as common features in disorders associated with intellectual disabilities, autism, and seizure activity, all common clinical manifestations of Rett syndrome (RTT), a neurodevelopmental disorder caused by loss-of-function mutations in the transcriptional regulator methyl-CpG-binding protein 2 (MeCP2). Here, we evaluated the consequences of Mecp2 mutation on hippocampal network excitability, as well as synapse structure and function using a combination of imaging and electrophysiological approaches in acute slices. Imaging the amplitude and spatiotemporal spread of neuronal depolarizations with voltage-sensitive dyes (VSD) revealed that the CA1 and CA3 regions of hippocampal slices from symptomatic male Mecp2 mutant mice are highly hyperexcitable. However, only the density of docked synaptic vesicles and the rate of release from the readily releasable pool are impaired in Mecp2 mutant mice, while synapse density and morphology are unaffected. The differences in network excitability were not observed in surgically isolated CA1 minislices, and blockade of GABAergic inhibition enhanced VSD signals to the same extent in Mecp2 mutant and wild-type mice, suggesting that network excitability originates in area CA3. Indeed, extracellular multiunit recordings revealed a higher level of spontaneous firing of CA3 pyramidal neurons in slices from symptomatic Mecp2 mutant mice. The neuromodulator adenosine reduced the amplitude and spatiotemporal spread of VSD signals evoked in CA1 of Mecp2 mutant slices to wild-type levels, suggesting its potential use as an anticonvulsant in RTT individuals. The present results suggest that hyperactive CA3 pyramidal neurons contribute to hippocampal dysfunction and possibly to limbic seizures observed in Mecp2 mutant mice and RTT individuals.
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Affiliation(s)
- Gaston Calfa
- Department of Neurobiology, Civitan International Research Center, The University of Alabama at Birmingham, Birmingham, AL 35294-2182, USA
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28
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Epilepsy in Rett syndrome: clinical and genetic features. Epilepsy Behav 2010; 19:296-300. [PMID: 20728410 DOI: 10.1016/j.yebeh.2010.06.051] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2010] [Revised: 06/25/2010] [Accepted: 06/28/2010] [Indexed: 11/23/2022]
Abstract
Epilepsy often occurs in Rett syndrome and is considered a major problem. The aim of this study was to define the clinical features of epilepsy and the correlation between seizures and both genotype and clinical phenotype in the Rett population. One hundred sixty-five patients with Rett syndrome referred to four Italian centers were recruited. All patients underwent video/EEG monitoring and molecular analysis of the MECP2 gene or, in negative cases, of the CDKL5 and FOXG1 genes. The frequency of epilepsy was 79%. Drug-resistant epilepsy occurred in 30% of all our patients with Rett syndrome and in 38% of those with epilepsy. Our findings demonstrate that epilepsy differs among the various phenotypes and genotypes with respect to age at onset, drug responsiveness, and seizure semiology. The Hanefeld and preserved speech variants represent the extremes of the range of severity of epilepsy: the preserved speech variant is characterized by the mildest epileptic phenotype as epilepsy is much less frequent, starts later, and is less drug resistant than what is observed in the other phenotypes. Another important finding is that seizure onset before 1 year of age and daily frequency are risk factors for drug resistance. Thus, this study should help clinicians provide better clinical counseling to the families of patients with Rett syndrome.
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29
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Gatto CL, Broadie K. Genetic controls balancing excitatory and inhibitory synaptogenesis in neurodevelopmental disorder models. Front Synaptic Neurosci 2010; 2:4. [PMID: 21423490 PMCID: PMC3059704 DOI: 10.3389/fnsyn.2010.00004] [Citation(s) in RCA: 106] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Accepted: 05/14/2010] [Indexed: 11/24/2022] Open
Abstract
Proper brain function requires stringent balance of excitatory and inhibitory synapse formation during neural circuit assembly. Mutation of genes that normally sculpt and maintain this balance results in severe dysfunction, causing neurodevelopmental disorders including autism, epilepsy and Rett syndrome. Such mutations may result in defective architectural structuring of synaptic connections, molecular assembly of synapses and/or functional synaptogenesis. The affected genes often encode synaptic components directly, but also include regulators that secondarily mediate the synthesis or assembly of synaptic proteins. The prime example is Fragile X syndrome (FXS), the leading heritable cause of both intellectual disability and autism spectrum disorders. FXS results from loss of mRNA-binding FMRP, which regulates synaptic transcript trafficking, stability and translation in activity-dependent synaptogenesis and plasticity mechanisms. Genetic models of FXS exhibit striking excitatory and inhibitory synapse imbalance, associated with impaired cognitive and social interaction behaviors. Downstream of translation control, a number of specific synaptic proteins regulate excitatory versus inhibitory synaptogenesis, independently or combinatorially, and loss of these proteins is also linked to disrupted neurodevelopment. The current effort is to define the cascade of events linking transcription, translation and the role of specific synaptic proteins in the maintenance of excitatory versus inhibitory synapses during neural circuit formation. This focus includes mechanisms that fine-tune excitation and inhibition during the refinement of functional synaptic circuits, and later modulate this balance throughout life. The use of powerful new genetic models has begun to shed light on the mechanistic bases of excitation/inhibition imbalance for a range of neurodevelopmental disease states.
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Affiliation(s)
- Cheryl L. Gatto
- Departments of Biological Sciences, Cell and Developmental Biology, Kennedy Center for Research on Human Development, Vanderbilt UniversityNashville, TN, USA
| | - Kendal Broadie
- Departments of Biological Sciences, Cell and Developmental Biology, Kennedy Center for Research on Human Development, Vanderbilt UniversityNashville, TN, USA
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30
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Nissenkorn A, Gak E, Vecsler M, Reznik H, Menascu S, Ben Zeev B. Epilepsy in Rett syndrome---the experience of a National Rett Center. Epilepsia 2010; 51:1252-8. [PMID: 20491871 DOI: 10.1111/j.1528-1167.2010.02597.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PURPOSE Rett syndrome (RTT), an X-linked, dominant neurodevelopmental disorder caused by mutations in the methyl-CpG-binding protein 2 (MECP2) gene, presents with acquired microcephaly, autistic regression, hand usage loss, and stereotypies. Epilepsy is frequent and has been reported to correlate with mutation type, general disease severity, and BDNF polymorphism. Our purpose was a comprehensive description of epilepsy features and course in RTT. METHODS Retrospective review of charts and electroencephalography (EEG) studies in 97 patients with RTT. RESULTS Seventy-two percent of patients had epilepsy, appearing at a median age of 3 years. According to age of onset, we divided patients into three groups: 6 with early epileptic variant (0-1 year), 42 with early epilepsy (1-5 years), and 20 with late epilepsy (after 5 years). Early epileptic variant had severe seizure types in the first year of life, followed by a typical RTT picture; all were MECP2 negative. Early epilepsy and late epilepsy groups were similar with respect to Rett-related symptoms, but seizures were better controlled in the second group (p < 0.05). Epileptiform activity appeared earlier and was more confluent in the early epilepsy group, including nine patients with electrical status epilepticus during sleep (ESES) versus one in the late epilepsy group (p < 0.05). No correlation was found between epilepsy onset or severity and genotype. BDNF val/met polymorphism correlated with earlier onset of seizures (p < 0.05). DISCUSSION Epilepsy appears earlier than described previously, frequently during the regression stage. Early age of onset predicts a more severe course of seizures. ESES is common among those with early onset epilepsy. BDNF polymorphism was the only genetic correlate with seizure onset, whereas MECP2 mutation type and location did not influence epilepsy.
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Affiliation(s)
- Andreea Nissenkorn
- Pediatric Neurology Unit, Safra Children Hospital, Tel Ha Shomer, Israel
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31
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Vignoli A, Fabio RA, La Briola F, Giannatiempo S, Antonietti A, Maggiolini S, Canevini MP. Correlations between neurophysiological, behavioral, and cognitive function in Rett syndrome. Epilepsy Behav 2010; 17:489-96. [PMID: 20236870 DOI: 10.1016/j.yebeh.2010.01.024] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2009] [Revised: 01/21/2010] [Accepted: 01/24/2010] [Indexed: 11/19/2022]
Abstract
Rett syndrome, a neurodevelopmental disorder affecting mainly females, is caused by a mutation of the MeCP2 gene. Girls with Rett syndrome manifest diverse behavioral and cognitive phenotypes, and the reasons for this variability remain unknown. In addition, girls with Rett syndrome often have epileptic seizures and abnormal EEGs, the characteristics of which differ with the patient. The aim of the study was to verify if neurophysiological and epileptological characteristics could be correlated with cognitive measures, obtained using eye tracker technology, and behavioral scores (Vineland Adaptive Behavior Scales and Rett Assessment Rating Scale) in 18 patients with Rett syndrome (mean age 13.7 years) at clinical stages III and IV. Age at epilepsy onset and seizure frequency were strictly correlated with neuropsychological outcome, as were EEG stage and distribution of paroxysmal abnormalities. Our findings demonstrate that neurophysiological features should be considered prognostic of cognitive and behavioral outcome in the clinical management of Rett syndrome.
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Affiliation(s)
- Aglaia Vignoli
- Centro Epilessia, Azienda Ospedaliera San Paolo, Università degli Studi di Milano, Milan, Italy.
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32
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Gika AD, Hughes E, Goyal S, Sparkes M, Lin JP. Trihexyphenidyl for acute life-threatening episodes due to a dystonic movement disorder in Rett syndrome. Mov Disord 2010; 25:385-9. [DOI: 10.1002/mds.22926] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Efficacy of levetiracetam in the treatment of drug-resistant Rett syndrome. Epilepsy Res 2009; 88:112-7. [PMID: 19914805 DOI: 10.1016/j.eplepsyres.2009.10.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 10/07/2009] [Accepted: 10/12/2009] [Indexed: 11/23/2022]
Abstract
Rett syndrome (RTT) is a progressive neurological disorder characterized by a wide spectrum of phenotypes. Epilepsy is reported to occur in 50-90% of patients with RTT; some develop medically refractory epilepsy. The aim of this study is to investigate the efficacy of levetiracetam (LEV) in drug-resistant patients with RTT. This prospective, pragmatic, open-label study consisted of an 8-week baseline period and a 6-month evaluation period. Efficacy variable was the mean frequency of monthly seizures before, and after 3 and 6 months of treatment with LEV. Eight female patients, aged 7.5-19 years (M12.8+/-5) entered the study. Mean age at epilepsy onset was 25.8+/-14.1 months. All patients showed MeCP2 mutation. Patients had been treated with a mean of 3.4 AEDs (2-7) before LEV. The mean LEV dose was 44.84+/-18.02mg/kg/day. The mean monthly seizure frequency for all types of seizures during the baseline period was 21.3+/-8.1 (range 10-35); after 3 months it was 3.3+/-4.1 (range 0-9) and after 6 months of LEV treatment it was 1.5+/-2 (range 0-4), p<0.0001. The mean follow-up period was 20.2+/-13 months. Mild sleepiness occurred in two patients, one reported intermittent agitation. Levetiracetam appeared effective in our series of drug-resistant RTT patients. All reported a reduction in seizure frequency and consequently a better quality of life.
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34
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A novel hypomorphic MECP2 point mutation is associated with a neuropsychiatric phenotype. Hum Genet 2008; 124:615-23. [PMID: 18989701 DOI: 10.1007/s00439-008-0585-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Accepted: 10/28/2008] [Indexed: 10/21/2022]
Abstract
The MECP2 gene on Xq28 encodes a transcriptional repressor, which binds to and modulates expression of active genes. Mutations in MECP2 cause classic or preserved speech variant Rett syndrome and intellectual disability in females and early demise or marked neurodevelopmental handicap in males. The consequences of a hypomorphic Mecp2 allele were recently investigated in a mouse model, which developed obesity, motor, social, learning, and behavioral deficits, predicting a human neurobehavioral syndrome. Here, we describe mutation analysis of a nondysmorphic female proband and her father who presented with primarily neuropsychiatric manifestations and obesity with relative sparing of intelligence, language, growth, and gross motor skills. We identified and characterized a novel missense mutation (c.454C>G; p.P152A) in the critical methyl-binding domain of MeCP2 that disrupts MeCP2 functional activity. We show that a gradient of impairment is present when the p.P152A mutation is compared with an allelic p.P152R mutation, which causes classic Rett syndrome and another Rett syndrome-causing mutation, such that protein-heterochromatin binding observed by immunofluorescence and immunoblotting is wild-type > P152A > P152R > T158 M, consistent with the severity of the observed phenotype. Our findings provide evidence for very mild phenotypes in humans associated with partial reduction of MeCP2 function arising from subtle variation in MECP2.
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35
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Temperini C, Innocenti A, Mastrolorenzo A, Scozzafava A, Supuran CT. Carbonic anhydrase inhibitors. Interaction of the antiepileptic drug sulthiame with twelve mammalian isoforms: Kinetic and X-ray crystallographic studies. Bioorg Med Chem Lett 2007; 17:4866-72. [PMID: 17588751 DOI: 10.1016/j.bmcl.2007.06.044] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2007] [Revised: 06/12/2007] [Accepted: 06/12/2007] [Indexed: 10/23/2022]
Abstract
Sulthiame, a clinically used antiepileptic, was investigated for its interaction with 12 catalytically active mammalian carbonic anhydrase (CA, EC 4.2.1.1) isoforms. The drug is a potent inhibitor of CA II, VII, IX, and XII (K(I)s of 6-56 nM), and a medium potency inhibitor against CA IV, VA, VB, and VI (K(I)s of 81-134 nM). The high resolution crystal structure of the hCA II-sulthiame adduct revealed a large number of favorable interactions between the drug and the enzyme which explain its strong low nanomolar affinity for this isoform and may also be exploited for the design of effective inhibitors incorporating sultam moieties.
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Affiliation(s)
- Claudia Temperini
- Università degli Studi di Firenze, Polo Scientifico, Laboratorio di Chimica Bioinorganica, Rm 188, Via della Lastruccia 3, 50019 Sesto Fiorentino (Florence), Italy
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36
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Abstract
Rett and Angelman syndromes comprise part of the spectrum of neurologic disorders associated with autism. Their clinical presentations overlap, with both presenting in later infancy with global developmental delays, severe speech and communication impairments, progressive microcephaly, seizures, autistic behaviors, and characteristic albeit different movement disorders and stereotypic hand movements. Although other features can help differentiate these disorders, significant phenotypic overlap and variation in severity sometimes cloud the underlying diagnosis. Rett syndrome is caused by a mutation in the MECP2 gene located on Xq28, whereas Angelman syndrome results from the loss of UBE3A function on chromosomal region 15q11-q13 related to a variety of molecular genetic mechanisms. Recent advances have uncovered interactions between these and other genes that affect the function and structure of neurons in the brain. The reversal of symptoms of Rett syndrome in a mature mouse model suggests the possibility for treatment of these and perhaps other autism-related disorders in the future.
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