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Dudley P, Marquez JP, Farrell F, Benson J, Rugg-Gunn F, Sidhu MK, O'Sullivan S, Walker M, Yogarajah M. Functional seizures and their mimics: a retrospective service review of cases from a tertiary video telemetry database. BMJ Neurol Open 2024; 6:e000738. [PMID: 39119525 PMCID: PMC11308881 DOI: 10.1136/bmjno-2024-000738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 07/01/2024] [Indexed: 08/10/2024] Open
Abstract
ABSTRACT Objective Identify the proportion of patients referred with putative functional seizures (FS) that were subsequently re-diagnosed as epileptic seizures (ES), or an alternative diagnosis, following video telemetry EEG (VTEEG). In addition, describe the characteristics of those seizures. Methods The VTEEG reports from patients admitted to the Chalfont Centre for Epilepsy between 2019 and 2022 were reviewed. Pre-VTEEG and post-VTEEG diagnoses were compared to identify whether a diagnostic revision was made from suspected FS to ES or another diagnosis. Diagnostic revision cases were then grouped into cohorts with associated features and reviewed to characterise and describe FS mimics. Results 444 VTEEG reports where patients had habitual events were identified. 4.7% of patients were referred with FS and were subsequently diagnosed with ES or another diagnosis. In this group, several cohorts could be identified including frontal lobe epileptic seizures, ES with functional overlay, insular or temporal lobe epileptic seizures associated with autonomic or marked experiential peri-ictal symptoms, and individuals who had both ES and FS but whose ES were revealed on medication withdrawal. Conclusion In patients referred to a tertiary epilepsy unit, a small minority of cases had seizures diagnosed as functional and reclassified as epileptic or an alternative diagnosis. It is clinically important to be aware of these FS mimics.
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Affiliation(s)
- Peter Dudley
- Department of Epilepsy, Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Jan Paul Marquez
- Department of Epilepsy, Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Fiona Farrell
- Department of Epilepsy, Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Jennifer Benson
- Department of Epilepsy, Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Fergus Rugg-Gunn
- Department of Epilepsy, Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
- NIHR University College London Hospitals Biomedical Research Centre, University College London, London, UK
| | - Meneka K Sidhu
- Department of Epilepsy, Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
- NIHR University College London Hospitals Biomedical Research Centre, University College London, London, UK
| | - Suzanne O'Sullivan
- Department of Epilepsy, Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
- NIHR University College London Hospitals Biomedical Research Centre, University College London, London, UK
| | - Matthew Walker
- Department of Epilepsy, Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
- NIHR University College London Hospitals Biomedical Research Centre, University College London, London, UK
| | - Mahinda Yogarajah
- Department of Epilepsy, Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London WC1N 3BG, UK
- NIHR University College London Hospitals Biomedical Research Centre, University College London, London, UK
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Bukhari-Parlakturk N, Frucht SJ. Isolated and combined dystonias: Update. HANDBOOK OF CLINICAL NEUROLOGY 2023; 196:425-442. [PMID: 37620082 DOI: 10.1016/b978-0-323-98817-9.00005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/26/2023]
Abstract
Dystonia is a hyperkinetic movement disorder with a unique motor phenomenology that can manifest as an isolated clinical syndrome or combined with other neurological features. This chapter reviews the characteristic features of dystonia phenomenology and the syndromic approach to evaluating the disorders that may allow us to differentiate the isolated and combined syndromes. We also present the most common types of isolated and combined dystonia syndromes. Since accelerated gene discoveries have increased our understanding of the molecular mechanisms of dystonia pathogenesis, we also present isolated and combined dystonia syndromes by shared biological pathways. Examples of these converging mechanisms of the isolated and combined dystonia syndromes include (1) disruption of the integrated response pathway through eukaryotic initiation factor 2 alpha signaling, (2) disease of dopaminergic signaling, (3) alterations in the cerebello-thalamic pathway, and (4) disease of protein mislocalization and stability. The discoveries that isolated and combined dystonia syndromes converge in shared biological pathways will aid in the development of clinical trials and therapeutic strategies targeting these convergent molecular pathways.
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Affiliation(s)
- Noreen Bukhari-Parlakturk
- Department of Neurology, Movement Disorders Division, Duke University (NBP), Durham, NC, United States.
| | - Steven J Frucht
- Department of Neurology, NYU Grossman School of Medicine (SJF), New York, NY, United States
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Park SM, Roache CE, Iffland PH, Moldenhauer HJ, Matychak KK, Plante AE, Lieberman AG, Crino PB, Meredith A. BK channel properties correlate with neurobehavioral severity in three KCNMA1-linked channelopathy mouse models. eLife 2022; 11:e77953. [PMID: 35819138 PMCID: PMC9275823 DOI: 10.7554/elife.77953] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 06/01/2022] [Indexed: 12/14/2022] Open
Abstract
KCNMA1 forms the pore of BK K+ channels, which regulate neuronal and muscle excitability. Recently, genetic screening identified heterozygous KCNMA1 variants in a subset of patients with debilitating paroxysmal non-kinesigenic dyskinesia, presenting with or without epilepsy (PNKD3). However, the relevance of KCNMA1 mutations and the basis for clinical heterogeneity in PNKD3 has not been established. Here, we evaluate the relative severity of three KCNMA1 patient variants in BK channels, neurons, and mice. In heterologous cells, BKN999S and BKD434G channels displayed gain-of-function (GOF) properties, whereas BKH444Q channels showed loss-of-function (LOF) properties. The relative degree of channel activity was BKN999S > BKD434G>WT > BKH444Q. BK currents and action potential firing were increased, and seizure thresholds decreased, in Kcnma1N999S/WT and Kcnma1D434G/WT transgenic mice but not Kcnma1H444Q/WT mice. In a novel behavioral test for paroxysmal dyskinesia, the more severely affected Kcnma1N999S/WT mice became immobile after stress. This was abrogated by acute dextroamphetamine treatment, consistent with PNKD3-affected individuals. Homozygous Kcnma1D434G/D434G mice showed similar immobility, but in contrast, homozygous Kcnma1H444Q/H444Q mice displayed hyperkinetic behavior. These data establish the relative pathogenic potential of patient alleles as N999S>D434G>H444Q and validate Kcnma1N999S/WT mice as a model for PNKD3 with increased seizure propensity.
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Affiliation(s)
- Su Mi Park
- Department of Physiology, University of Maryland School of MedicineBaltimoreUnited States
| | - Cooper E Roache
- Department of Physiology, University of Maryland School of MedicineBaltimoreUnited States
| | - Philip H Iffland
- Department of Neurology, University of Maryland School of MedicineBaltimoreUnited States
| | - Hans J Moldenhauer
- Department of Physiology, University of Maryland School of MedicineBaltimoreUnited States
| | - Katia K Matychak
- Department of Physiology, University of Maryland School of MedicineBaltimoreUnited States
| | - Amber E Plante
- Department of Physiology, University of Maryland School of MedicineBaltimoreUnited States
| | - Abby G Lieberman
- Department of Pharmacology, University of Maryland School of MedicineBaltimoreUnited States
| | - Peter B Crino
- Department of Neurology, University of Maryland School of MedicineBaltimoreUnited States
| | - Andrea Meredith
- Department of Physiology, University of Maryland School of MedicineBaltimoreUnited States
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Motoyama R, Matsudaira T, Terada K, Usui N, Yoshiura KI, Takahashi Y. PRRT2 mutation in a Japanese woman: Adult-onset focal epilepsy coexisting with movement disorders and cerebellar atrophy. Epilepsy Behav Rep 2022; 19:100554. [PMID: 35712060 PMCID: PMC9194843 DOI: 10.1016/j.ebr.2022.100554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Revised: 04/23/2022] [Accepted: 05/16/2022] [Indexed: 11/17/2022] Open
Abstract
Mutation of the PRRT2 gene in a Japanese woman resulted in the c.604_607del variant. Her clinical features presented with focal epilepsy, cerebellar atrophy, paroxysmal kinesigenic dyskinesia, and paroxysmal non-kinesigenic dystonia (PNKD). Video-EEG monitoring revealed that her epilepsy arose from the left temporal region. Low dose lamotrigine was effective for her epilepsy and PNKD.
Proline-rich transmembrane protein 2 (PRRT2) was confirmed as the causative gene of paroxysmal kinesigenic dyskinesia (PKD) as shown by genome-wide linkage analyses. PRRT2 mutations are also associated with benign familial infantile seizures, infantile convulsions and choreoathetosis, and childhood absence epilepsy, but few reports have investigated adult-onset epilepsy. We describe here a rare presentation of adult-onset focal epilepsy with a PRRT2 mutation in a 31-year-old woman who showed cerebellar atrophy, familial paroxysmal kinesigenic dyskinesia, and paroxysmal non-kinesigenic dystonia. Video-electroencephalography (EEG) demonstrated focal impaired awareness seizures, in which ictal EEG changes showed left temporal onset with rhythmic theta activity over the left temporal region. Magnetic resonance imaging showed mild cerebellar atrophy. The administration of lamotrigine 50 mg/day resulted in freedom from her seizures and lamotrigine 150 mg/day reduced paroxysmal non-kinesigenic dystonia. Furthermore, she had a rare frameshift mutation, c.604_607del, p.Ser202fs of which the pathogenicity has been reported in ClinVar, but it has not been reported in Japan. Mutation of the PRRT2 gene can cause adult-onset epilepsy, paroxysmal non-kinesigenic movement disorder, and cerebellar atrophy, suggesting an expanding clinical phenotypic spectrum associated with PRRT2 mutations.
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Liao JY, Salles PA, Shuaib UA, Fernandez HH. Genetic updates on paroxysmal dyskinesias. J Neural Transm (Vienna) 2021; 128:447-471. [PMID: 33929620 DOI: 10.1007/s00702-021-02335-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 03/31/2021] [Indexed: 12/17/2022]
Abstract
The paroxysmal dyskinesias are a diverse group of genetic disorders that manifest as episodic movements, with specific triggers, attack frequency, and duration. With recent advances in genetic sequencing, the number of genetic variants associated with paroxysmal dyskinesia has dramatically increased, and it is now evident that there is significant genotype-phenotype overlap, reduced (or incomplete) penetrance, and phenotypic variability. In addition, a variety of genetic conditions can present with paroxysmal dyskinesia as the initial symptom. This review will cover the 34 genes implicated to date and propose a diagnostic workflow featuring judicious use of whole-exome or -genome sequencing. The goal of this review is to provide a common understanding of paroxysmal dyskinesias so basic scientists, geneticists, and clinicians can collaborate effectively to provide diagnoses and treatments for patients.
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Affiliation(s)
- James Y Liao
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Philippe A Salles
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
- Centro de Trastornos del Movimiento, CETRAM, Santiago, Chile
| | - Umar A Shuaib
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA
| | - Hubert H Fernandez
- Center for Neurological Restoration, Neurological Institute, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
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Furukawa G, Negishi Y, Takeuchi T, Ishihara N, Okumura A. Lacosamide for children with paroxysmal kinesigenic dyskinesia. Brain Dev 2020; 42:617-620. [PMID: 32430160 DOI: 10.1016/j.braindev.2020.04.009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 04/19/2020] [Accepted: 04/21/2020] [Indexed: 02/03/2023]
Abstract
OBJECTIVES This study was performed to evaluate the efficacy and tolerability of lacosamide (LCM) for paroxysmal kinesigenic dyskinesia (PKD) in children. METHODS We retrospectively reviewed the medical charts of pediatric PKD patients (aged <16 years) treated with LCM. Data regarding demographic characteristics, proline-rich transmembrane protein 2 (PRRT2) gene variant, clinical features of PKD, dose of LCM, efficacy, and adverse events were recorded. RESULTS Four eligible patients (3 males, 1 female) were identified, with an age of onset ranging from 8.3 to 14.7 years. PRRT2 variant was evaluated in three children and a c.649dupC variant was identified in one child with a positive family history. Attacks were bilateral in three children and left-sided in one. Two children had a family history of PKD and one child had a family history of benign infantile epilepsy. Treatment with carbamazepine failed in two children due to drowsiness and auditory disturbance. The initial dose of LCM was 50 mg/day in three children and 100 mg/day in one. All patients were attack-free within a few days. The maintenance dose was mostly similar to the initial dose. No adverse events related to LCM were reported during follow-up. CONCLUSIONS LCM is an effective and well-tolerated treatment for PKD in children, and low-dose treatment may be viable.
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Affiliation(s)
- Gen Furukawa
- Department of Pediatrics, Toyokawa City Hospital, Japan.
| | - Yutaka Negishi
- Department of Pediatrics, Gifu Prefectural Tajimi Hospital, Japan
| | - Tomoya Takeuchi
- Department of Pediatrics, Japanese Red Cross Nagoya Daiichi Hospital, Japan
| | - Naoko Ishihara
- Department of Pediatrics, Fujita Health University School of Medicine, Japan
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