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Indelicato E, Boesch S. CACNA1A-Related Channelopathies: Clinical Manifestations and Treatment Options. Handb Exp Pharmacol 2023; 279:227-248. [PMID: 36592223 DOI: 10.1007/164_2022_625] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In the last decade, variants in the Ca2+ channel gene CACNA1A emerged as a frequent aetiology of rare neurological phenotypes sharing a common denominator of variable paroxysmal manifestations and chronic cerebellar dysfunction. The spectrum of paroxysmal manifestations encompasses migraine with hemiplegic aura, episodic ataxia, epilepsy and paroxysmal non-epileptic movement disorders. Additional chronic neurological symptoms range from severe developmental phenotypes in early-onset cases to neurobehavioural disorders and chronic cerebellar ataxia in older children and adults.In the present review we systematically approach the clinical manifestations of CACNA1A variants, delineate genotype-phenotype correlations and elaborate on the emerging concept of an age-dependent phenotypic spectrum in CACNA1A disease. We furthermore reflect on different therapy options available for paroxysmal symptoms in CACNA1A and address open issues to prioritize in the future clinical research.
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Affiliation(s)
- Elisabetta Indelicato
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria.
| | - Sylvia Boesch
- Center for Rare Movement Disorders Innsbruck, Department of Neurology, Medical University of Innsbruck, Innsbruck, Austria
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2
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Brasil S, Allocca M, Magrinho SCM, Santos I, Raposo M, Francisco R, Pascoal C, Martins T, Videira PA, Pereira F, Andreotti G, Jaeken J, Kantautas KA, Perlstein EO, Ferreira VDR. Systematic Review: Drug Repositioning for Congenital Disorders of Glycosylation (CDG). Int J Mol Sci 2022; 23:ijms23158725. [PMID: 35955863 PMCID: PMC9369176 DOI: 10.3390/ijms23158725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/02/2022] [Accepted: 08/02/2022] [Indexed: 11/24/2022] Open
Abstract
Advances in research have boosted therapy development for congenital disorders of glycosylation (CDG), a group of rare genetic disorders affecting protein and lipid glycosylation and glycosylphosphatidylinositol anchor biosynthesis. The (re)use of known drugs for novel medical purposes, known as drug repositioning, is growing for both common and rare disorders. The latest innovation concerns the rational search for repositioned molecules which also benefits from artificial intelligence (AI). Compared to traditional methods, drug repositioning accelerates the overall drug discovery process while saving costs. This is particularly valuable for rare diseases. AI tools have proven their worth in diagnosis, in disease classification and characterization, and ultimately in therapy discovery in rare diseases. The availability of biomarkers and reliable disease models is critical for research and development of new drugs, especially for rare and heterogeneous diseases such as CDG. This work reviews the literature related to repositioned drugs for CDG, discovered by serendipity or through a systemic approach. Recent advances in biomarkers and disease models are also outlined as well as stakeholders’ views on AI for therapy discovery in CDG.
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Affiliation(s)
- Sandra Brasil
- UCIBIO—Applied Molecular Biosciences Unit, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, Nova University of Lisbon, 2829-516 Caparica, Portugal
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
| | - Mariateresa Allocca
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Institute of Biomolecular Chemistry, National Research Council of Italy, 80078 Pozzuoli, Italy
- Department of Environmental, Biological and Pharmaceutical Sciences and Technologies, University of Campania “Luigi Vanvitelli”, 81100 Caserta, Italy
| | - Salvador C. M. Magrinho
- UCIBIO—Applied Molecular Biosciences Unit, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, Nova University of Lisbon, 2829-516 Caparica, Portugal
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- LAQV-Requimte, Chemistry Department, School of Science and Technology, Nova University of Lisbon, 2819-516 Caparica, Portugal
| | - Inês Santos
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Sci and Volunteer Program from School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
| | - Madalena Raposo
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Sci and Volunteer Program from School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
| | - Rita Francisco
- UCIBIO—Applied Molecular Biosciences Unit, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, Nova University of Lisbon, 2829-516 Caparica, Portugal
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
| | - Carlota Pascoal
- UCIBIO—Applied Molecular Biosciences Unit, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, Nova University of Lisbon, 2829-516 Caparica, Portugal
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
| | - Tiago Martins
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Sci and Volunteer Program from School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
| | - Paula A. Videira
- UCIBIO—Applied Molecular Biosciences Unit, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, Nova University of Lisbon, 2829-516 Caparica, Portugal
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
| | - Florbela Pereira
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- LAQV-Requimte, Chemistry Department, School of Science and Technology, Nova University of Lisbon, 2819-516 Caparica, Portugal
| | - Giuseppina Andreotti
- Institute of Biomolecular Chemistry, National Research Council of Italy, 80078 Pozzuoli, Italy
| | - Jaak Jaeken
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Center for Metabolic Diseases, Department of Pediatrics, KU Leuven, 3000 Leuven, Belgium
| | | | | | - Vanessa dos Reis Ferreira
- UCIBIO—Applied Molecular Biosciences Unit, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy, School of Science and Technology, Nova University of Lisbon, 2829-516 Caparica, Portugal
- CDG & Allies PPAIN—Professionals and Patient Associations International Network, Department of Life Sciences, School of Science and Technology, NOVA University of Lisbon, 2819-516 Caparica, Portugal
- Correspondence:
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3
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Du Z, Li P, Bing D. Presence of diabetes mellitus affects vertigo outcome in vestibular migraine. Am J Otolaryngol 2022; 43:103562. [DOI: 10.1016/j.amjoto.2022.103562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Revised: 06/24/2022] [Accepted: 07/31/2022] [Indexed: 11/01/2022]
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4
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Park JH, Marquardt T. Treatment Options in Congenital Disorders of Glycosylation. Front Genet 2021; 12:735348. [PMID: 34567084 PMCID: PMC8461064 DOI: 10.3389/fgene.2021.735348] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Accepted: 08/23/2021] [Indexed: 12/15/2022] Open
Abstract
Despite advances in the identification and diagnosis of congenital disorders of glycosylation (CDG), treatment options remain limited and are often constrained to symptomatic management of disease manifestations. However, recent years have seen significant advances in treatment and novel therapies aimed both at the causative defect and secondary disease manifestations have been transferred from bench to bedside. In this review, we aim to give a detailed overview of the available therapies and rising concepts to treat these ultra-rare diseases.
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Affiliation(s)
- Julien H Park
- Department of General Pediatrics, Metabolic Diseases, University Children's Hospital Münster, Münster, Germany
| | - Thorsten Marquardt
- Department of General Pediatrics, Metabolic Diseases, University Children's Hospital Münster, Münster, Germany
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5
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Martínez-Monseny AF, Bolasell M, Callejón-Póo L, Cuadras D, Freniche V, Itzep DC, Gassiot S, Arango P, Casas-Alba D, de la Morena E, Corral J, Montero R, Pérez-Cerdá C, Pérez B, Artuch R, Jaeken J, Serrano M. AZATAX: Acetazolamide safety and efficacy in cerebellar syndrome in PMM2 congenital disorder of glycosylation (PMM2-CDG). Ann Neurol 2019; 85:740-751. [PMID: 30873657 DOI: 10.1002/ana.25457] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Revised: 03/03/2019] [Accepted: 03/05/2019] [Indexed: 12/26/2022]
Abstract
OBJECTIVE Phosphomannomutase deficiency (PMM2 congenital disorder of glycosylation [PMM2-CDG]) causes cerebellar syndrome and strokelike episodes (SLEs). SLEs are also described in patients with gain-of-function mutations in the CaV2.1 channel, for which acetazolamide therapy is suggested. Impairment in N-glycosylation of CaV2.1 promotes gain-of-function effects and may participate in cerebellar syndrome in PMM2-CDG. AZATAX was designed to establish whether acetazolamide is safe and improves cerebellar syndrome in PMM2-CDG. METHODS A clinical trial included PMM2-CDG patients, with a 6-month first-phase single acetazolamide therapy group, followed by a randomized 5-week withdrawal phase. Safety was assessed. The primary outcome measure was improvement in the International Cooperative Ataxia Rating Scale (ICARS). Other measures were the Nijmegen Pediatric CDG Rating Scale (NPCRS), a syllable repetition test (PATA test), and cognitive scores. RESULTS Twenty-four patients (mean age = 12.3 ± 4.5 years) were included, showing no serious adverse events. Thirteen patients required dose adjustment due to low bicarbonate or asthenia. There were improvements on ICARS (34.9 ± 23.2 vs 40.7 ± 24.8, effect size = 1.48, 95% confidence interval [CI] = 4.0-7.6, p < 0.001), detected at 6 weeks in 18 patients among the 20 responders, on NPCRS (95% CI = 0.3-1.6, p = 0.013) and on the PATA test (95% CI = 0.5-3.0, p = 0.006). Acetazolamide improved prothrombin time, factor X, and antithrombin. Clinical severity, epilepsy, and lipodystrophy predicted greater response. The randomized withdrawal phase showed ICARS worsening in the withdrawal group (effect size = 1.46, 95% CI = 2.65-7.52, p = 0.001). INTERPRETATION AZATAX is the first clinical trial of PMM2-CDG. Acetazolamide is well tolerated and effective for motor cerebellar syndrome. Its ability to prevent SLEs and its long-term effects on kidney function should be addressed in future studies. Ann Neurol 2019;85:740-751.
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Affiliation(s)
- Antonio F Martínez-Monseny
- Genetic Medicine Department and Pediatric Institute of Rare Diseases, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain
| | - Mercè Bolasell
- Genetic Medicine Department and Pediatric Institute of Rare Diseases, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain
| | - Laura Callejón-Póo
- Neuropsychology Unit, Neuroesplugues, Esplugues de Llobregat, Barcelona, Spain
| | - Daniel Cuadras
- Statistics Department, Sant Joan de Déu Foundation, Barcelona, Spain
| | - Verónica Freniche
- Neuropsychology Unit, Neuroesplugues, Esplugues de Llobregat, Barcelona, Spain
| | - Débora C Itzep
- Neuropediatric Department, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain
| | - Susanna Gassiot
- Hematology Laboratory, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain
| | - Pedro Arango
- Nephrology Department, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain
| | - Didac Casas-Alba
- Genetic Medicine Department and Pediatric Institute of Rare Diseases, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain
| | - Eugenia de la Morena
- Hematology and Medical Oncology Service, Morales Meseguer University Hospital, Regional Blood Donation Center, Murcia University, IMIB-Arrixaca, U-765, Center for Biomedical Research on Rare Diseases, Murcia, Spain
| | - Javier Corral
- Hematology and Medical Oncology Service, Morales Meseguer University Hospital, Regional Blood Donation Center, Murcia University, IMIB-Arrixaca, U-765, Center for Biomedical Research on Rare Diseases, Murcia, Spain
| | - Raquel Montero
- Clinical Biochemistry Department, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain.,U-703, Center for Biomedical Research on Rare Diseases, Instituto de Salud Carlos III, Sant Joan de Déu Hospital, Barcelona, Spain
| | - Celia Pérez-Cerdá
- Diagnosis of Molecular Diseases Center, Autonomous University of Madrid, U-746, Center for Biomedical Research on Rare Diseases, Instituto de Salud Carlos III, IdiPAZ, Madrid, Spain
| | - Belén Pérez
- Diagnosis of Molecular Diseases Center, Autonomous University of Madrid, U-746, Center for Biomedical Research on Rare Diseases, Instituto de Salud Carlos III, IdiPAZ, Madrid, Spain
| | - Rafael Artuch
- Clinical Biochemistry Department, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain.,U-703, Center for Biomedical Research on Rare Diseases, Instituto de Salud Carlos III, Sant Joan de Déu Hospital, Barcelona, Spain
| | - Jaak Jaeken
- Center for Metabolic Disease, University Hospital Gasthuisberg, Catholic University of Leuven, Leuven, Belgium
| | - Mercedes Serrano
- Genetic Medicine Department and Pediatric Institute of Rare Diseases, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain.,Neuropediatric Department, Sant Joan de Déu Hospital Research Institute, Barcelona, Spain.,U-703, Center for Biomedical Research on Rare Diseases, Instituto de Salud Carlos III, Sant Joan de Déu Hospital, Barcelona, Spain
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6
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Suzuki M, Fujiwara K, Tsubuku T, Yabe I, Sasaki H, Fukuda S. Time course of downbeat positioning nystagmus in familial hemiplegic migraine type 1 treated with acetazolamide. J Neurol Sci 2016; 368:206-8. [PMID: 27538634 DOI: 10.1016/j.jns.2016.07.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 06/21/2016] [Accepted: 07/11/2016] [Indexed: 01/03/2023]
Affiliation(s)
- Masanobu Suzuki
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Hokkaido University, Japan
| | - Keishi Fujiwara
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Hokkaido University, Japan.
| | - Takashi Tsubuku
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Hokkaido University, Japan
| | - Ichiro Yabe
- Department of Neurology, Graduate School of Medicine, Hokkaido University, Japan
| | - Hidenao Sasaki
- Department of Neurology, Graduate School of Medicine, Hokkaido University, Japan
| | - Satoshi Fukuda
- Department of Otolaryngology, Head and Neck Surgery, Graduate School of Medicine, Hokkaido University, Japan
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7
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Leach EL, van Karnebeek CDM, Townsend KN, Tarailo-Graovac M, Hukin J, Gibson WT. Episodic ataxia associated with a de novo SCN2A mutation. Eur J Paediatr Neurol 2016; 20:772-6. [PMID: 27328862 DOI: 10.1016/j.ejpn.2016.05.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 05/04/2016] [Accepted: 05/26/2016] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Episodic ataxia (EA) is characterized by paroxysmal attacks of ataxia interspersed by asymptomatic periods. Dominant mutations or copy number variants in CACNA1A are a well-known cause of EA. CLINICAL PRESENTATION This boy presented with clinical features of episodic ataxia, and also showed cerebellar atrophy, hypotonia, autism and global developmental delay at age 4 years. Acetazolamide prevented further episodes of ataxia, dystonia and encephalopathy. Extensive biochemical and genetic tests were unrevealing; whole exome sequencing found a previously unreported variant in SCN2A, proven to be de novo and predicted to be protein-damaging. CONCLUSION Considered alongside previous reports of episodic ataxia in SCN2A mutation-positive patients, our case further illustrates the genetic heterogeneity of episodic ataxia. In addition, this case suggests that acetazolamide may be an effective treatment for some aspects of the phenotype in a broader range of channelopathy-related conditions.
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Affiliation(s)
- Emma L Leach
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada
| | - Clara D M van Karnebeek
- Division of Biochemical Diseases, Department of Pediatrics, British Columbia Children's Hospital, Vancouver, Canada; Child and Family Research Institute, British Columbia Children's Hospital, Vancouver, Canada; Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Katelin N Townsend
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada; Child and Family Research Institute, British Columbia Children's Hospital, Vancouver, Canada
| | - Maja Tarailo-Graovac
- Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, Canada
| | - Juliette Hukin
- Division of Neurology, Department of Pediatrics, British Columbia Children's Hospital, Vancouver, Canada
| | - William T Gibson
- Department of Medical Genetics, University of British Columbia, Vancouver, Canada; Child and Family Research Institute, British Columbia Children's Hospital, Vancouver, Canada.
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8
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Exercise-induced downbeat nystagmus in a Korean family with a nonsense mutation in CACNA1A. Neurol Sci 2015; 36:1393-6. [PMID: 25784583 DOI: 10.1007/s10072-015-2157-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 03/06/2015] [Indexed: 10/23/2022]
Abstract
Episodic ataxia type 2 (EA2) is characterized by recurrent attacks of vertigo and ataxia lasting hours triggered by emotional stress or exercise. Although interictal horizontal gaze-evoked nystagmus and rebound nystagmus are commonly observed in patients with EA2, the nystagmus has been rarely reported during the vertigo attack. To better describe exercise-induced nystagmus in EA2, four affected members from three generations of a Korean family with EA2 received full neurological and neuro-otological evaluations. Vertigo was provoked in the proband with running for 10 min to record eye movements during the vertigo attack. We performed a polymerase chain reaction-based direct sequence analysis of all coding regions of CACNA1A in all participants. The four affected members had a history of exertional vertigo, imbalance, childhood epilepsy, headache, and paresthesia. The provocation induced severe vertigo and imbalance lasting several hours, and oculography documented pure downbeat nystagmus during the attack. Genetic analyses identified a nonsense mutation in exon 23 which has been registered in dbSNP as a pathogenic allele (c.3832C>T, p.R1278X) in all the affected members. Ictal downbeat nystagmus in the studied family indicates cerebellar dysfunction during the vertigo attack in EA2. In patients with episodic vertigo and ataxia, the observation of exercise-induced nystagmus would provide a clue for EA2.
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9
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Rajakulendran S, Kaski D, Hanna MG. Neuronal P/Q-type calcium channel dysfunction in inherited disorders of the CNS. Nat Rev Neurol 2012; 8:86-96. [PMID: 22249839 DOI: 10.1038/nrneurol.2011.228] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The past two decades have witnessed the emergence of a new and expanding field of neurological diseases--the genetic ion channelopathies. These disorders arise from mutations in genes that encode ion channel subunits, and manifest as paroxysmal attacks involving the brain or spinal cord, and/or muscle. The voltage-gated P/Q-type calcium channel (P/Q channel) is highly expressed in the cerebellum, hippocampus and cortex of the mammalian brain. The P/Q channel has a fundamental role in mediating fast synaptic transmission at central and peripheral nerve terminals. Autosomal dominant mutations in the CACNA1A gene, which encodes voltage-gated P/Q-type calcium channel subunit α(1) (the principal pore-forming subunit of the P/Q channel) are associated with episodic and progressive forms of cerebellar ataxia, familial hemiplegic migraine, vertigo and epilepsy. This Review considers, from both a clinical and genetic perspective, the various neurological phenotypes arising from inherited P/Q channel dysfunction, with a focus on recent advances in the understanding of the pathogenetic mechanisms underlying these disorders.
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Affiliation(s)
- Sanjeev Rajakulendran
- Medical Research Council Center for Neuromuscular Diseases, Box 102, National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
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Abstract
The episodic ataxias are autosomal dominant disorders usually beginning in the first two decades of life. Episodic ataxia type 1 (EA1) is characterized by brief episodes of ataxia, typically lasting seconds, and interictal myokymia, while episodic ataxia type 2 (EA2) is manifested by longer episodes of ataxia (hours) with interictal nystagmus. The EA1 gene (KCNA1) codes for the six transmembrane segments (S1 to S6) of the Kv1.1 potassium channel subunit and the EA2 gene (CACNA1A) encodes for the Ca(v)2.1 subunit of the P/Q calcium channel complex. EA1 mutations are always missense while most EA2 mutations disrupt the reading frame. Studies of the biophysical properties of the mutant Kv1.1 and Ca(v)2.1 channels in Xenopus oocytes and mammalian cell lines demonstrate clear physiologic consequences of the genetic mutations although no consistent pattern for genotype-phenotype correlation has emerged. Genetic testing for EA1 and EA2 is available, but since no single mutation is prominent for either KCNA1 or CACNA1A, all of the coding regions of the genes need to be screened for mutations. Acetazolamide can be dramatic in controlling episodes of ataxia with EA2 but is typically less beneficial with EA1.
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Affiliation(s)
- Robert W Baloh
- Department of Neurology, University of California, Los Angeles, CA 90095-1769, USA.
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11
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Waeber C, Hargreaves R. Current and emerging therapies for migraine prevention and treatment. HANDBOOK OF CLINICAL NEUROLOGY 2010; 97:789-809. [PMID: 20816471 DOI: 10.1016/s0072-9752(10)97065-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
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12
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Steinlein OK. Human disorders caused by the disruption of the regulation of excitatory neurotransmission. Results Probl Cell Differ 2008; 44:223-42. [PMID: 17589814 DOI: 10.1007/400_2007_034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
The nicotinic acetylcholine receptors (nAChRs) are members of the large family of ligand-gated ion channels, and are constituted by the assembly of five subunits arranged pseudosymmetrically around the central axis that forms a cation-selective ion pore. They are widely distributed in both the nervous system and non-neuronal tissues, and can be activated by endogenous agonists such as acetylcholine or exogenous ligands such as nicotine. Mutations in neuronal nAChRs are found in a rare form of familial nocturnal frontal lobe epilepsy (ADNFLE), while mutations in the neuromuscular subtype of the nAChR are responsible for either congenital myasthenia syndromes (adult subtype of neuromuscular nAChR) or a form of arthrogryposis multiplex congenita type Escobar (fetal subtype of neuromuscular nAChR).
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Affiliation(s)
- Ortrud K Steinlein
- Institute of Human Genetics, Ludwig-Maximilians-University, School of Medicine, Goethestr. 29, 80336 München, Germany.
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13
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Abstract
Clinical and pathophysiological evidences connect migraine and the cerebellum. Literature on documented cerebellar abnormalities in migraine, however, is relatively sparse. Cerebellar involvement may be observed in 4 types of migraines: in the widespread migraine with aura (MWA) and migraine without aura (MWoA) forms; in particular subtypes of migraine such as basilar-type migraine (BTM); and in the genetically driven autosomal dominant familial hemiplegic migraine (FHM) forms. Cerebellar dysfunction in migraineurs varies largely in severity, and may be subclinical. Purkinje cells express calcium channels that are related to the pathophysiology of both inherited forms of migraine and primary ataxias, mostly spinal cerebellar ataxia type 6 (SCA-6) and episodic ataxia type 2 (EA-2). Genetically driven ion channels dysfunction leads to hyperexcitability in the brain and cerebellum, possibly facilitating spreading depression waves in both locations. This review focuses on the cerebellar involvement in migraine, the relevant ataxias and their association with this primary headache, and discusses some of the pathophysiological processes putatively underlying these diseases.
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Affiliation(s)
- Maurice Vincent
- Hospital Universitário Clementino Fraga Filho, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Brazil
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14
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Abstract
Episodic ataxia type 2 (EA 2) is a rare neurological disorder of autosomal dominant inheritance resulting from dysfunction of a voltage-gated calcium channel. It manifests with recurrent disabling attacks of imbalance, vertigo, and ataxia, and can be provoked by physical exertion or emotional stress. In the spell-free interval, patients present with central ocular motor dysfunction, mainly downbeat nystagmus. A slow progression of cerebellar signs accompanied by a slight atrophy of midline cerebellar structures is commonly observed during the course of the disease. EA 2 is caused most often by the loss of function mutations of the calcium channel gene CACNA1A, which encodes the Ca(v)2.1 subunit of the P/Q-type calcium channel and is primarily expressed in Purkinje cells. To date, more than 30 mutations have been described. Two effective treatment options have been established for EA 2: acetazolamide (ACTZ), which probably changes the intracellular pH and thereby the transmembraneous potential, and 4-aminopyridine (4-AP), a potassium channel blocker. Approximately 70% of all patients respond to treatment with ACTZ, but the effect is often only transient. In an open trial, 4-AP prevented attacks in five of six patients with EA 2, most likely by increasing the resting activity and excitability of the Purkinje cells. These findings were confirmed by experiments in animal models of EA 2. Many aspects of the pathophysiology (e.g., induction of the attacks) and treatment of EA 2 (e.g., mode of action of ACTZ and 4-AP) still remain unclear and need to be addressed in further animal and clinical studies.
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Affiliation(s)
- Michael Strupp
- Department of Neurology, University of Munich, Munich, Germany.
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15
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Rajakulendran S, Schorge S, Kullmann DM, Hanna MG. Episodic ataxia type 1: a neuronal potassium channelopathy. Neurotherapeutics 2007; 4:258-66. [PMID: 17395136 DOI: 10.1016/j.nurt.2007.01.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Episodic ataxia type 1 is a paroxysmal neurological disorder characterized by short-lived attacks of recurrent midline cerebellar dysfunction and continuous motor activity. Mutations in KCN1A, the gene encoding Kv1.1, a voltage-gated neuronal potassium channel, are associated with the disorder. Although rare, the syndrome highlights the fundamental features of genetic ion-channel diseases and serves as a useful model for understanding more common paroxysmal disorders, such as epilepsy and migraine. This review examines our current understanding of episodic ataxia type 1, focusing on its clinical and genetic features, pathophysiology, and treatment.
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Affiliation(s)
- Sanjeev Rajakulendran
- Department of Molecular Neuroscience, Centre for Neuromuscular Disease, Queen Square, London WC1N 3BG, United Kingdom
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16
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Felix R. Calcium channelopathies. Neuromolecular Med 2007; 8:307-18. [PMID: 16775382 DOI: 10.1385/nmm:8:3:307] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2005] [Revised: 11/30/1999] [Accepted: 01/20/2006] [Indexed: 11/11/2022]
Abstract
Intracellular calcium ([Ca2+]i) is highly regulated in eukaryotic cells. The free [Ca2+]i is approximately four orders of magnitude less than that in the extracellular environment. It is, therefore, an electrochemical gradient favoring Ca2+ entry, and transient cellular activation increasing Ca2+ permeability will lead to a transient increase in [Ca2+]i. These transient rises of [Ca2+]i trigger or regulate diverse intracellular events, including metabolic processes, muscle contraction, secretion of hormones and neurotransmitters, cell differentiation, and gene expression. Hence, changes in [Ca2+]i act as a second messenger system coordinating modifications in the external environment with intracellular processes. Notably, information on the molecular genetics of the membrane channels responsible for the influx of Ca2+ ions has led to the discovery that mutations in these proteins are linked to human disease. Ca2+ channel dysfunction is now known to be the basis for several neurological and muscle disorders such as migraine, ataxia, and periodic paralysis. In contrast to other types of genetic diseases, Ca2+ channelopathies can be studied with precision by electrophysiological methods, and in some cases, the results have been highly rewarding with a biophysical phenotype that correlates with the ultimate clinical phenotype. This review outlines recent advances in genetic, molecular, and pathophysiological aspects of human Ca2+ channelopathies.
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Affiliation(s)
- Ricardo Felix
- Department of Cell Biology, Center for Research and Advanced Studies, National Polytechnic Institute (Cinvestav-IPN), Mexico City, Mexico.
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Kim JM, Kim JS, Ki CS, Jeon BS. Episodic Ataxia Type 2 due to a Deletion Mutation in the CACNA1A Gene in a Korean Family. J Clin Neurol 2006; 2:268-71. [PMID: 20396531 PMCID: PMC2854978 DOI: 10.3988/jcn.2006.2.4.268] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2006] [Accepted: 09/25/2006] [Indexed: 11/17/2022] Open
Abstract
Episodic ataxia type 2 (EA-2) is an inherited disorder that is characterized by intermittent vertigo, ataxia, and interictal gaze-evoked nystagmus. Although abnormalities associated with this disorder have been found in the CACNA1A gene encoding the alpha1A (Cav2.1) subunit of the P/Q-type calcium channel, there are few reports of genetically confirmed EA-2 in Korea. In 1998, a Korean family with acetazolamide-responsive hereditary paroxysmal ataxia was reported, but the genetic background was not defined at that time. In the present study we performed direct sequencing of the entire exons and their flanking intronic sequences of the CACNA1A gene and found a deletion mutation (c.2042_2043delAG).
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Affiliation(s)
- Jeong-Min Kim
- Department of Neurology, College of Medicine, Seoul National University, Korea
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Pantazis A, Keegan P, Postma M, Schwiening CJ. The effect of neuronal morphology and membrane-permeant weak acid and base on the dissipation of depolarization-induced pH gradients in snail neurons. Pflugers Arch 2005; 452:175-87. [PMID: 16341877 DOI: 10.1007/s00424-005-0019-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2005] [Revised: 09/15/2005] [Accepted: 10/26/2005] [Indexed: 10/25/2022]
Abstract
Neuronal depolarization causes larger intracellular pH (pH(i)) shifts in axonal and dendritic regions than in the cell body. In this paper, we present evidence relating the time for collapse of these gradients to neuronal morphology. We have used ratiometric pH(i) measurements using 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) in whole-cell patch-clamped snail neurons to study the collapse of longitudinal pH gradients. Using depolarization to open voltage-gated proton channels, we produced alkaline pH(i) microdomains. In the absence of added mobile buffers, facilitated H(+) diffusion down the length of the axon plays a critical role in determining pH(i) microdomain lifetime, with axons of approximately 100 microm allowing pH differences to be maintained for >60 s. An application of mobile, membrane-permeant pH buffers accelerated the collapse of the alkaline-pH gradients but, even at 30 mM, was unable to abolish them. Modeling of the pH(i) dynamics showed that both the relatively weak effect of the weak acid/base on the peak size of the pH gradient and the accelerated collapse of the pH gradient could be due to the time taken for equilibration of the weak acid and base across the cell. We propose that appropriate weak acid/base mixes may provide a simple method for studying the role of local pH(i) signals without perturbing steady-state pH(i). Furthermore, an extrapolation of our in vitro data to longer and thinner neuronal structures found in the mammalian nervous system suggests that dendritic and axonal pH(i) are likely to be dominated by local pH(i)-regulating mechanisms rather than simply following the soma pH(i).
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Affiliation(s)
- A Pantazis
- Department of Anatomy, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
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19
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Dressler D, Benecke R. Diagnosis and management of acute movement disorders. J Neurol 2005; 252:1299-306. [PMID: 16208529 DOI: 10.1007/s00415-005-0006-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2005] [Accepted: 04/20/2005] [Indexed: 10/25/2022]
Abstract
Most movement disorders, reflecting degenerative disorders, develop in a slowly progressive fashion. Some movement disorders, however, manifest with an acute onset. We wish to give an overview of the management and therapy of those acute-onset movement disorders.Drug-induced movement disorders are mainly caused by dopamine-receptor blockers (DRB) as used as antipsychotics (neuroleptics) and antiemetics. Acute dystonic reactions usually occur within the first four days of treatment. Typically, cranial pharyngeal and cervical muscles are affected. Anticholinergics produce a prompt relief. Akathisia is characterized by an often exceedingly bothersome feeling of restlessness and the inability to remain still. It is a common side effect of DRB and occurs within few days after their initiation. It subsides when DRB are ceased. Neuroleptic Malignant Syndrome is a rare, but life-threatening adverse reaction to DRB which may occur at any time during DRB application. It is characterised by hyperthermia, rigidity, reduced consciousness and autonomic failure. Therapeutically immediate DRB withdrawal is crucial. Additional dantrolene or bromocriptine application together with symptomatic treatment may be necessary. Paroxysmal dyskinesias are childhood onset disorders characterised by dystonic postures, chorea, athetosis and ballism occurring at irregular intervals. In Paroxysmal Kinesigenic Dyskinesia they are triggered by rapid movements, startle reactions or hyperventilation. They last up to 5 minutes, occur up to 100 times per day and are highly sensitive to anticonvulsants. In Paroxysmal Non-Kinesiogenic Dyskinesia they cannot be triggered, occur less frequently and last longer. Other paroxysmal dyskinesias include hypnogenic paroxysmal dyskinesias, paroxysmal exertional dyskinesia, infantile paroxysmal dystonias, Sandifer's syndrome and symptomatic paroxysmal dyskinesias. In Hereditary Episodic Ataxia Type 1 attacks of ataxia last for up to two minutes, may be accompanied by dysarthria and dystonia and usually respond to phenytoin. In Type 2 they can last for several hours, may be accompanied by vertigo, headache and malaise and usually respond to acetazolamide. Symptomatic episodic ataxias can occur in a number of metabolic disorders, but also in multiple sclerosis and Behcet's disease.
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Affiliation(s)
- D Dressler
- Dept. of Neurology, Rostock University, Gehlsheimer Str. 20, 18147 Rostock, Germany.
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Viau M, Boulanger Y. Characterization of ataxias with magnetic resonance imaging and spectroscopy. Parkinsonism Relat Disord 2004; 10:335-51. [PMID: 15261875 DOI: 10.1016/j.parkreldis.2004.02.006] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/27/2003] [Revised: 02/17/2004] [Accepted: 02/26/2004] [Indexed: 11/19/2022]
Abstract
A wide variety of autosomal transmitted ataxias exist and their ultimate characterization requires genetic testing. Common clinical characteristics among different ataxia types complicate the choice of the appropriate genetic test. Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) generally show cerebellar or cerebral atrophy and perturbed metabolite levels which differ between ataxias. In order to help the clinician accurately identify the ataxia type, reported MRI and MRS data in different brain regions are summarized for more than 60 different types of autosomal inherited and sporadic ataxias.
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Affiliation(s)
- Martin Viau
- Département de Radiologie, Hôpital Saint-Luc, Centre Hospitalier de l'Université de Montréal, 1058 St-Denis, Montréal, Québec, Canada H2X 3J4
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Margolis RL. Dominant spinocerebellar ataxias: a molecular approach to classification, diagnosis, pathogenesis and the future. Expert Rev Mol Diagn 2004; 3:715-32. [PMID: 14628900 DOI: 10.1586/14737159.3.6.715] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The capacity to use molecular techniques to establish the genetic diagnoses of the autosomal dominant ataxias has revolutionized the field. It is now possible to systematically classify these disorders according to the nature of the causative mutation, with implications for diagnostic testing, analysis of pathogenesis and therapeutic strategies. Here, the disorders are grouped into ataxias caused by CAG repeat expansions that encode polyglutamine, ataxias caused by mutations in ion channels, ataxias caused by repeat expansions that do not encode polyglutamine, and ataxias caused by point mutations. The clinical, pathological, genetic and pathogenic features of each disorder are considered and the current status and future of diagnosis and therapy are reviewed in light of this classification scheme.
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Affiliation(s)
- Russell L Margolis
- Department of Psychiatry, Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Matsuyama Z, Murase M, Shimizu H, Aoki Y, Hayashi M, Hozumi I, Inuzuka T. A novel insertion mutation of acetazolamide-responsive episodic ataxia in a Japanese family. J Neurol Sci 2003; 210:91-3. [PMID: 12736095 DOI: 10.1016/s0022-510x(03)00008-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We report a Japanese family with acetazolamide-responsive episodic ataxia. The proband was a 41-year-old woman with interictal nystagmus. She experienced recurrent attacks of loss of equilibrium and loss of coordination of the extremities accompanied by dysarthria and nausea beginning at about 10 years old. These episodes usually lasted for several hours two or three times a week. Direct sequence of CACNA1A demonstrated a novel insertion mutation in the patient and her father. This mutation is estimated to cause early stop of the gene transcription, producing a truncated protein. This is the first report of episodic ataxia type 2 of which the mutation was identified in a Japanese family.
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Affiliation(s)
- Zenjiro Matsuyama
- Department of Neurology and Geriatrics, Gifu University, School of Medicine, Tsukasa-Machi, Gifu 500-8705, Japan.
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Abstract
Optical imaging of activity-dependent pH changes using neutral red has revealed a novel form of propagated activity in the cerebellar cortex: spreading acidification and depression (SAD). Evoked by surface stimulation, SAD is characterized by a propagation geometry that reflects the parasagittal architecture of the cerebellum, high speed of propagation across several folia, and a transient depression of the molecular layer circuitry. The properties of SAD differentiate it from other forms of propagating activity in the nervous system including spreading depression and Ca++ waves. Involving several factors, SAD is hypothesized to be a regenerative process that requires a functioning parallel fibers-Purkinje cell circuit, glutamatergic neurotransmission, and is initiated by increased neuronal excitability. Three possible neuronal and glia substrates in the cerebellar cortex could account for the propagation geometry of SAD. Recently, the authors demonstrated that blocking voltage-gated Kv1.1 potassium channels plays a major role in the generation of SAD. This observation has lead to the hypothesis that the episodic and transient disruption in cerebellar function that characterizes episodic ataxia type 1, a Kv1.1 channelopathy, is due to SAD occurring in the cerebellar cortex.
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Affiliation(s)
- Timothy J Ebner
- Department of Neuroscience, University of Minnesota, Minneapolis 55455, USA.
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24
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Abstract
In the past decade, the genetic etiologies accounting for most cases of adult-onset dominant cerebellar ataxia have been discovered. This group of disorders, generally referred to as the spinocerebellar ataxias (SCAs), can now be classified by a simple genetic nosology, essentially a sequential list in which each new SCA is given a number. However, recent advances in the elucidation of SCA pathogenesis provide the opportunity to subclassify the disorders into three discrete groups based on pathogenesis: 1) the polyglutamine disorders, SCAs 1, 2, 3, 7, and 17, which result from proteins with toxic stretches of polyglutamine; 2) the channelopathies, SCA6 and episodic ataxia types 1 and 2 (EA1 and EA2), which result from disruption of calcium or potassium channel function; and 3) the gene expression disorders, SCAs 8, 10, and 12, which result from repeat expansions outside of coding regions that may quantitatively alter gene expression. SCAs 4, 5, 9, 11, 13-16, 19, 21, and 22 are of unknown etiology, and may or may not fit into one of these three groups. At present, most diagnostic and therapeutic strategies apply equally to all of the SCAs. Therapy specific for individual diseases or types of diseases is a realistic goal in the foreseeable future.
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Affiliation(s)
- Russell L Margolis
- Laboratory of Genetic Neurobiology, Division of Neurobiology, Department of Psychiatry and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, 600 North Wolfe Street, Baltimore, MD 21287, USA.
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25
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Abstract
This review addresses the molecular and cellular mechanisms of diseases caused by inherited mutations of ion channels in neurones. Among important recent advances is the elucidation of several dominantly inherited epilepsies caused by mutations of both voltage-gated and ligand-gated ion channels. The neuronal channelopathies show evidence of phenotypic convergence; notably, episodic ataxia can be caused by mutations of either calcium or potassium channels. The channelopathies also show evidence of phenotypic divergence; for instance, different mutations of the same calcium channel gene are associated with familial hemiplegic migraine, episodic or progressive ataxia, coma and epilepsy. Future developments are likely to include the discovery of other ion channel genes associated with inherited and sporadic CNS disorders. The full range of manifestations of inherited ion channel mutations remains to be established.
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Affiliation(s)
- Dimitri M Kullmann
- Institute of Neurology, University College London, Queen Square, London WC1N 3BG, UK.
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26
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Abstract
The familial episodic ataxias are prototypical inherited channelopathies that result in episodes of vertigo and ataxia triggered by stress and exercise. Episodic ataxia type 1 (EA-1) is caused by missense mutations in the potassium channel gene KCNA1, whereas episodic ataxia type 2 (EA-2) is caused by missense and nonsense mutations in the calcium channel gene CACNA1A. These ion channels are crucial for both central and peripheral neurotransmission. Within the last few years, the genetic mechanisms underlying these relatively rare familial episodic ataxia syndromes have been worked out. They provide a model for understanding the mechanisms of more common recurrent vertigo and ataxia syndromes, particularly those associated with migraine. Migraine affects as many as 15-20% of the general population, and it has been estimated that about 25% of patients with migraine experience spontaneous attacks of vertigo and ataxia. We identified 24 families with migraine and benign recurrent vertigo inherited in an autosomal dominant fashion. These families have numerous features in common with EA-1 and EA-2 (particularly EA-2), suggesting that benign recurrent vertigo may be an inherited channelopathy. An ion channel mutation shared by brain and inner ear could explain the combined central and peripheral features of the syndrome.
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Affiliation(s)
- Robert W Baloh
- Department of Neurology and Division of Surgery (Head and Neck), UCLA School of Medicine, Los Angeles, California 90095-1769, USA.
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Kors EE, Terwindt GM, Vermeulen FL, Fitzsimons RB, Jardine PE, Heywood P, Love S, van den Maagdenberg AM, Haan J, Frants RR, Ferrari MD. Delayed cerebral edema and fatal coma after minor head trauma: role of the CACNA1A calcium channel subunit gene and relationship with familial hemiplegic migraine. Ann Neurol 2001; 49:753-60. [PMID: 11409427 DOI: 10.1002/ana.1031] [Citation(s) in RCA: 220] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Trivial head trauma may be complicated by severe, sometimes even fatal, cerebral edema and coma occurring after a lucid interval ("delayed cerebral edema"). Attacks of familial hemiplegic migraine (FHM) can be triggered by minor head trauma and are sometimes accompanied by coma. Mutations in the CACNA1A calcium channel subunit gene on chromosome 19 are associated with a wide spectrum of mutation-specific episodic and chronic neurological disorders, including FHM with or without coma. We investigated the role of the CACNA1A gene in three subjects with delayed cerebral edema. Two subjects originated from a family with extreme FHM, and one subject was the previously asymptomatic daughter of a sporadic patient with hemiplegic migraine attacks. In all three subjects with delayed severe edema, we found a C-to-T substitution resulting in the substitution of serine for lysine at codon 218 (S218L) in the CACNA1A gene. The mutation was absent in nonaffected family members and 152 control individuals. Haplotype analysis excluded a common founder for both families. Neuropathological examination in one subject showed Purkinje cell loss with relative preservation of granule cells and sparing of the dentate and inferior olivary nuclei. We conclude that the novel S218L mutation in the CACNA1A calcium channel subunit gene is involved in FHM and delayed fatal cerebral edema and coma after minor head trauma. This finding may have important implications for the understanding and treatment of this dramatic syndrome.
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Affiliation(s)
- E E Kors
- Department of Neurology, Leiden University Medical Centre, The Netherlands
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28
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Kullmann DM, Rea R, Spauschus A, Jouvenceau A. The inherited episodic ataxias: how well do we understand the disease mechanisms? Neuroscientist 2001; 7:80-8. [PMID: 11486347 DOI: 10.1177/107385840100700111] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The past few years have seen the elucidation of several neurological diseases caused by inherited mutations of ion channels. In contrast to many other types of genetic disorders, the "channelopathies" can be studied with high precision by applying electrophysiological methods. This review evaluates the success of this approach in explaining the mechanisms of two forms of episodic ataxia that are known to be caused by mutations of ion channels: episodic ataxia type 1 (EA1, caused by K+ channel mutations) and episodic ataxia type 2 (EA2, caused by Ca2+ channel mutations). Although both of these disorders are rare, they raise many important questions about the roles of identified channels in brain function. Indeed, a resolution of the mechanisms by which both diseases occur will represent a major milestone in understanding diseases of the CNS, in addition to opening the way to novel possible treatments.
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Affiliation(s)
- D M Kullmann
- University Department of Clinical Neurology, Institute of Neurology, National Hospital for Neurology and Neurosurgery, Queen Square London WC1N 3BG, UK
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29
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Grzesiuk AK. [Non-familial episodic ataxia possibly associated with the use of nicotine: case report]. ARQUIVOS DE NEURO-PSIQUIATRIA 2000; 58:756-9. [PMID: 10973123 DOI: 10.1590/s0004-282x2000000400027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The author reports a case of non-familial episodic ataxia responsive to acetazolamide, clinically similar to episodic ataxia type 2 (EA-2), in which nicotine is a possible factor in the origin of the ataxic episodes.
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30
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Sappey-Marinier D, Vighetto A, Peyron R, Broussolle E, Bonmartin A. Phosphorus and proton magnetic resonance spectroscopy in episodic ataxia type 2. Ann Neurol 1999; 46:256-9. [PMID: 10443893 DOI: 10.1002/1531-8249(199908)46:2<256::aid-ana17>3.0.co;2-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Localized phosphorus (31P) and proton (1H) magnetic resonance spectroscopy was performed in the cerebellum and the occipital lobe of 6 patients with episodic ataxia type 2. From use of 31P magnetic resonance spectroscopy, untreated patients showed decreased high-energy phosphate ratios in the cerebrum, and increased pH in the cerebellum and cerebrum, which normalized under acetazolamide. 1H magnetic resonance spectra demonstrated high lactate peaks in 3 of the 6 patients. These metabolic alterations, probably induced by the calcium channelopathy, may characterize episodic ataxia type 2.
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31
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Affiliation(s)
- M Onofrj
- Department of Oncology and Neuroscience, Institute of Neurology, University G.D'Annunzio, Chieti, Italy
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32
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Yue Q, Jen JC, Thwe MM, Nelson SF, Baloh RW. De novo mutation in CACNA1A caused acetazolamide-responsive episodic ataxia. AMERICAN JOURNAL OF MEDICAL GENETICS 1998; 77:298-301. [PMID: 9600739 DOI: 10.1002/(sici)1096-8628(19980526)77:4<298::aid-ajmg9>3.0.co;2-j] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
With the recent report of mutations in the calcium channel gene CACNA1A in two families with episodic ataxia type 2, we investigated a patient with nonfamilial episodic vertigo and ataxia responsive to acetazolamide for similar mutations. Single-strand conformation polymorphism (SSCP) analysis of exon 23 identified an extra band in the patient that was not present in other relatives or in normal controls. Exon 23 of the patient showed a spontaneous C to T substitution at position 4410 resulting in an early stop codon. Patients with nonfamilial episodic ataxia may respond to acetazolamide and may have mutations in CACNA1A.
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Affiliation(s)
- Q Yue
- Department of Neurology, UCLA School of Medicine, Los Angeles, California 90095-1769, USA
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33
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Abstract
Clinical details are given of different types of episodic ataxia: type 1, with myokymia, and attacks which usually last a few minutes, and may occur several times a day, and treatment with acetazolamide can reduce the number of attacks; type 2, with interictal nystagmus, and attacks which last for several hours to a day or more, and treatment with acetazolamide is very effective; paroxysmal choreoathetosis with episodic ataxia, with attacks lasting for about 20 min and occurring at varying intervals; and familial hemiplegic migraine, with transient hemiplegia presenting during the aura of a migraine headache, the symptoms improving on treatment with acetazolamide. Their inheritance is of dominant type; and the gene for type 1 is mapped to chromosome 12p near to a cluster of potassium channel genes, and that for type 2 and for familial hemiplegic migraine to chromosome 19p near to calcium channel genes. The differential diagnosis from other conditions with a periodic symptomatology is discussed, especially from a number of metabolic disorders. Treatment is effective for many of these, and the treatment of the episodic ataxias with acetazolamide can sometimes have a dramatic effect. The possible role of the channelopathies in the causation of some periodic neurological disorders is considered; with the expectation that further research will improve the identification of specific diseases, and lead to more effective treatment.
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34
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Yue Q, Jen JC, Nelson SF, Baloh RW. Progressive ataxia due to a missense mutation in a calcium-channel gene. Am J Hum Genet 1997; 61:1078-87. [PMID: 9345107 PMCID: PMC1716037 DOI: 10.1086/301613] [Citation(s) in RCA: 128] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We describe a family with severe progressive cerebellar ataxia involving the trunk, the extremities, and speech. The proband, who has prominent atrophy of the cerebellum, shown by magnetic resonance imaging, was confined to a wheelchair at the age of 44 years. Two sons have episodes of vertigo and ataxia that are not responsive to acetazolamide. Quantitative eye-movement testing showed a consistent pattern of abnormalities localizing to the cerebellum. Genotyping suggested linkage to chromosome 19p, and SSCP showed an aberrant migrating fragment in exon 6 of the calcium-channel gene CACNA1A, which cosegregated with the disease. Sequencing of exon 6 identified a G-->A transposition in one allele, at nucleotide 1152, resulting in a predicted glycine-to-arginine substitution at codon 293. The CAG-repeat expansion associated with spinocerebellar ataxia 6 was not present in any family members. This family is unique in having a non-CAG-repeat mutation that leads to severe progressive ataxia. Since a great deal is known about the function of calcium channels, we speculate on how this missense mutation leads to the combination of clinical symptoms and signs.
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Affiliation(s)
- Q Yue
- Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-1769, USA
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35
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Jodice C, Mantuano E, Veneziano L, Trettel F, Sabbadini G, Calandriello L, Francia A, Spadaro M, Pierelli F, Salvi F, Ophoff RA, Frants RR, Frontali M. Episodic ataxia type 2 (EA2) and spinocerebellar ataxia type 6 (SCA6) due to CAG repeat expansion in the CACNA1A gene on chromosome 19p. Hum Mol Genet 1997; 6:1973-8. [PMID: 9302278 DOI: 10.1093/hmg/6.11.1973] [Citation(s) in RCA: 200] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Point mutations of the CACNA1A gene coding for the alpha 1A voltage-dependent calcium channel subunit are responsible for familial hemiplegic migraine (FHM) and episodic ataxia type 2 (EA2). In addition, expansions of the CAG repeat motif at the 3' end of the gene, smaller than those responsible for dynamic mutation disorders, were found in patients with a progressive spinocerebellar ataxia, named SCA6. In the present work, the analysis of two new families with small CAG expansions of the CACNA1A gene is presented. In one family, with a clinical diagnosis of EA2, a CAG23 repeat allele segregated in patients showing different interictal symptoms, ranging from nystagmus only to severe progressive cerebellar ataxia. No additional mutations in coding and intron-exon junction sequences in disequilibrium with the CAG expansion were found. In the second family, initially classified as autosomal dominant cerebellar ataxia of unknown type, an inter-generational allele size change showed that a CAG20 allele was associated with an EA2 phenotype and a CAG25 allele with progressive cerebellar ataxia. These results show that EA2 and SCA6 are the same disorder with a high phenotypic variability, at least partly related to the number of repeats, and suggest that the small expansions may not be as stable as previously reported. A refinement of the coding and intron-exon junction sequences of the CACNA1A gene is also provided.
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Affiliation(s)
- C Jodice
- Dipartimento di Biologia, Università di Tor Vergata, Rome, Italy
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36
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Abstract
The molecular diversity of K(+)-selective channels far exceeds any other group of voltage- or ligand-gated channels, reflecting their early ancestral origin. This diversity is mirrored by the broad spectrum of physiological functions subserved by these proteins. Potassium channels modulate the resting potential and action potential duration of neurons, myocytes and endocrine cells and stabilize the membrane potential of excitable and nonexcitable cells. In addition to channel diversity, differential cellular expression of K+ channels determines the specific electrical responses to stimuli in a particular cell or tissue. This study reviews the recent genetic and physiological studies of congenital disorders caused by mutations in genes encoding K+ channels. These include the human disorders of episodic ataxia with myokymia, long QT syndrome and Bartter's syndrome, and weaver ataxia in mice. An understanding of the molecular basis of these diseases could facilitate the discovery and development of specific pharmacological therapies.
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Affiliation(s)
- M C Sanguinetti
- Department of Medicine, University of Utah, Salt Lake City 84112, USA.
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37
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Abstract
Although family studies and twin studies are not sufficiently reliable to establish this theory with certainty, migraine likely is influenced by hereditary susceptibility. The association of migraine with a large number of hereditary diseases opens the possibility to choose candidate chromosomes for linkage studies. A rare subtype of migraine, familial hemiplegic migraine, is linked to chromosome 19p and at least one other locus. The chromosome 19p also seems to be involved in "normal" migraine, although conflicting results have been reported.
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Affiliation(s)
- J Haan
- Department of Neurology, Leiden University Hospital, The Netherlands
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38
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Baloh RW, Yue Q, Furman JM, Nelson SF. Familial episodic ataxia: clinical heterogeneity in four families linked to chromosome 19p. Ann Neurol 1997; 41:8-16. [PMID: 9005860 DOI: 10.1002/ana.410410105] [Citation(s) in RCA: 117] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We describe the clinical and oculographic findings in 4 families with episodic ataxia and interictal nystagmus (EA-2) linked to chromosome 19p. Episodes varied from pure ataxia to combinations of symptoms suggesting involvement of the cerebellum, brainstem, and cortex. Some affected individuals exhibited a progressive ataxia syndrome phenotypically indistinguishable from the dominantly inherited spinocerebellar ataxia (SCA) syndromes. About one-half of the affected individuals had migraine headaches and several had episodes typical of basilar migraine. Oculographic findings were localizing to the vestibulocerebellum and posterior vermis. Additional genetic and environmental factors must account for the marked clinical heterogeneity in these families with an abnormal gene on chromosome 19p.
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Affiliation(s)
- R W Baloh
- Department of Neurology, UCLA School of Medicine, Los Angeles, CA 90095-1769, USA
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39
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Dangond F, Garada B, Murawski BJ, Rey-Casserly C, Holman BL, Mikati MA. Focal brain dysfunction in a 41-year old man with familial alternating hemiplegia. Eur Arch Psychiatry Clin Neurosci 1997; 247:35-41. [PMID: 9088804 DOI: 10.1007/bf02916251] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The acute pathophysiologic changes during hemiplegic spells and the long-term outcome of alternating hemiplegia remain obscure. In a 41-year-old male with familial alternating hemiplegia we found an increase in right frontal cerebral blood flow 3 h into a 5-h left hemiplegic episode. A repeat high-resolution brain SPECT study performed 26 h after the resolution of the left hemiplegia revealed normalization of the frontal blood flow accompanied by hyperperfusion in the right parietal lobe. An interictal SPECT scan several weeks later showed no asymmetries. Head CT and MRI scans were negative. Neuropsychologic assessment and neurologic examination revealed evidence of a diffuse disorder which predominantly involved the right hemisphere. To our knowledge, there are no previous correlative studies of serial high-resolution brain SPECT with MRI, or of detailed neuropsychologic assessment, in adult patients with such an advanced course of alternating hemiplegia of childhood.
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Affiliation(s)
- F Dangond
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
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40
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Neufeld MY, Nisipeanu P, Chistik V, Korczyn AD. The electroencephalogram in acetazolamide-responsive periodic ataxia. Mov Disord 1996; 11:283-8. [PMID: 8723146 DOI: 10.1002/mds.870110312] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Acetazolamide-responsive periodic ataxia (ARPA) is a rare movement disorder, characterized by recurrent episodes of vertigo, cerebellar ataxia, and nystagmus, which has recently been characterized genetically. The pathophysiology is unknown, but it is probably not epileptic. By definition, acetazolamide produces an impressive symptomatic relief. Because of the paroxysmal nature of the disorder, EEG tracings were often obtained. We report four new cases (two familial and two sporadic) with typical ARPA (none of whom had metabolic abnormalities or continuous electrical muscle activity) and review the EEG findings associated with this disorder. EEG findings were reported in 18 kindreds and nine sporadic cases (including ours). EEG was described in 54 of the 140 affected cases and was abnormal in 52% (28/54). Most commonly seen was intermittent generalized slow activity, observed in 35% (19/54), frequently intermingled with spikes (10 cases). Other abnormalities included nonspecific mild generalized or focal slowing in seven (13%) and focal epileptic activity in two (4%) patients. The paroxysmal EEG activity frequently seen in ARPA should not establish a diagnosis of epilepsy. Although not specific, it may suggest the correct diagnosis and indicate treatment with acetazolamide.
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Affiliation(s)
- M Y Neufeld
- Department of Neurology, Tel-Aviv Elias Sourasky Medical Center, Israel
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41
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Van Bogaert P, Szliwowski HB. EEG findings in acetazolamide-responsive hereditary paroxysmal ataxia. Neurophysiol Clin 1996; 26:335-40. [PMID: 8987050 DOI: 10.1016/s0987-7053(97)85101-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
EEG studies were performed in six family members affected by acetazolamide-responsive paroxysmal ataxia. Intermittent rhythmic delta activity was found at rest in five of them; low amplitude spikes were associated with delta waves in two cases, resulting in irregular spike and wave patterns. Slowing of background activity was present in three patients. EEG abnormalities were activated by hyperventilation and modified neither by intermittent photic stimulation, nor by acetazolamide therapy. Our results suggest that EEG may be helpful to recognize this rare, but well defined, treatable disorder.
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Affiliation(s)
- P Van Bogaert
- Département de Neurologie (Neurologie Pédiatrique), Hôpital Erasme, Université Libre de Bruxelles, Bruxelles, Belgique
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42
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43
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Poza JJ, Martí Massó JF, Amato E. Late onset familial periodic cerebellar ataxia. Mov Disord 1995; 10:224-5. [PMID: 7753068 DOI: 10.1002/mds.870100217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Affiliation(s)
- J J Poza
- Neurological Service, Hospital Ntra. Sra. Aránzazu San Sebastián, Spain
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44
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Vahedi K, Joutel A, Van Bogaert P, Ducros A, Maciazeck J, Bach JF, Bousser MG, Tournier-Lasserve E. A gene for hereditary paroxysmal cerebellar ataxia maps to chromosome 19p. Ann Neurol 1995; 37:289-93. [PMID: 7695228 DOI: 10.1002/ana.410370304] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Hereditary paroxysmal cerebellar ataxia (HPCA) is an autosomal dominant disorder characterized by the recurrence of intermittent attacks of vestibulocerebellar ataxia lasting from 15 minutes to a few days. The number of attacks is often significantly decreased by acetazolamide treatment. Neurological examination shows a permanent gaze-evoked nystagmus, as well as a mild cerebellar ataxia in most patients. The paroxysmal feature of this condition is shared by another autosomal dominant neurological condition, familial hemiplegic migraine (FHM), a condition in which permanent cerebellar signs have also been reported in some families. Although hemiplegic migraine has never been reported in patients with HPCA, we hypothesized, based on the latter observations, that HPCA and FHM may be allelic disorders. We previously mapped a gene responsible for FHM on the short arm of chromosome 19. We performed linkage analysis with 6 markers spanning the FHM interval on a large HPCA family. Significant lod scores were obtained with 3 markers: D19S244 (LS = 3.71), D19S221 (3.60), and D19S226 (3.54) at theta = 0. Haplotype and multipoint linkage analysis established that the most likely location was the same interval of 30 cM encompassing the chromosome 19 FHM locus.
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Affiliation(s)
- K Vahedi
- Inserm U25, Faculté de Médecine Necker-Enfants-Malades, Paris, France
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45
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Ng WK, Tan CT. Paroxysmal cerebellar ataxia: use of phenytoin as a provocation test. AUSTRALIAN AND NEW ZEALAND JOURNAL OF MEDICINE 1994; 24:583. [PMID: 7848171 DOI: 10.1111/j.1445-5994.1994.tb01770.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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46
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Abstract
There is a scant literature regarding vestibular evaluation of children with complaints of dizziness or vertigo. Considerable time and effort are expended on the problem and prevention of hearing loss in children, yet we often ignore concurrent or subsequent vestibular disorders. This neglect could be due to several factors, perhaps the most common being the fact that vertiginous crises in childhood are often attributed to problems of behavior or incoordination. In this article, we offer an approach to the dizzy child based on presenting symptoms. We discuss features of the history, examination, and laboratory evaluation key to determining the cause of dizziness. Finally, we discuss management, which varies according to the diagnosis.
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Affiliation(s)
- R J Tusa
- Department of Otolaryngology, University of Miami School of Medicine, FL 33101
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47
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Vion-Dury J, Meyerhoff DJ, Cozzone PJ, Weiner MW. What might be the impact on neurology of the analysis of brain metabolism by in vivo magnetic resonance spectroscopy? J Neurol 1994; 241:354-71. [PMID: 7931430 DOI: 10.1007/bf02033352] [Citation(s) in RCA: 106] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
In vivo nuclear magnetic resonance spectroscopy (MRS) of the human brain is a recently developed technique which allows to assay noninvasively in vivo key molecules of brain metabolism. After a review of the origin of the signals detected by phosphorus and proton MRS of human brain, the impact of MRS on clinical neurology is examined. MRS of the brain does not purport to be a metabolic "biopsy", but unique applications for brain MRS are (1) quantitating the oxidative state of the brain and defining neuronal death, (2) assessing and mapping neuron damage, (3) evaluating membrane alterations, and (4) characterizing encephalopathies. In the near future brain MRS will be performed routinely after conventional MRI, as a valuable metabolic (and functional) complement to the anatomical evaluation of cerebral pathologies, particularly the toxic, metabolic and infectious encephalopathies.
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