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van der Veen S, Eggink H, Elting JWJ, Sival D, Verschuuren-Bemelmans CC, de Koning TJ, Tijssen MAJ. The natural history of progressive myoclonus ataxia. Neurobiol Dis 2024; 199:106555. [PMID: 38844245 DOI: 10.1016/j.nbd.2024.106555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2024] [Revised: 05/22/2024] [Accepted: 06/03/2024] [Indexed: 06/16/2024] Open
Abstract
Progressive myoclonus ataxia (PMA) is a rare clinical syndrome characterized by the presence of progressive myoclonus and ataxia, and can be accompanied by mild cognitive impairment and infrequent epileptic seizures. This is the first study to describe the natural history of PMA and identify clinical, electrophysiological, and genetic features explaining the variability in disease progression. A Dutch cohort of consecutive patients meeting the criteria of the refined definition of PMA was included. The current phenotype was assessed during in-person consultation by movement disorders experts, and retrospective data was collected to describe disease presentation and progression, including brain imaging and therapy efficacy. Extensive genetic and electrophysiological tests were performed. The presence of cortical hyperexcitability was determined, by either the identification of a cortical correlate of myoclonic jerks with simultaneous electromyography-electroencephalography or a giant somatosensory evoked potential. We included 34 patients with PMA with a median disease duration of 15 years and a clear progressive course in most patients (76%). A molecular etiology was identified in 82% patients: ATM, CAMTA1, DHDDS, EBF3, GOSR2, ITPR1, KCNC3, NUS1, POLR1A, PRKCG, SEMA6B, SPTBN2, TPP1, ZMYND11, and a 12p13.32 deletion. The natural history is a rather homogenous onset of ataxia in the first two years of life followed by myoclonus in the first 5 years of life. Main accompanying neurological dysfunctions included cognitive impairment (62%), epilepsy (38%), autism spectrum disorder (27%), and behavioral problems (18%). Disease progression showed large variability ranging from an epilepsy free PMA phenotype (62%) to evolution towards a progressive myoclonus epilepsy (PME) phenotype (18%): the existence of a PMA-PME spectrum. Cortical hyperexcitability could be tested in 17 patients, and was present in 11 patients and supported cortical myoclonus. Interestingly, post-hoc analysis showed that an absence of cortical hyperexcitability, suggesting non-cortical myoclonus, was associated with the PMA-end of the spectrum with no epilepsy and milder myoclonus, independent of disease duration. An association between the underlying genetic defects and progression on the PMA-PME spectrum was observed. By describing the natural history of the largest cohort of published patients with PMA so far, we see a homogeneous onset with variable disease progression, in which phenotypic evolution to PME occurs in the minority. Genetic and electrophysiological features may be of prognostic value, especially the determination of cortical hyperexcitability. Furthermore, the identification of cortical and non-cortical myoclonus in PMA helps us gain insight in the underlying pathophysiology of myoclonus.
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Affiliation(s)
- Sterre van der Veen
- Department of Neurology, University of Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands; Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands
| | - Hendriekje Eggink
- Department of Neurology, University of Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands; Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands
| | - Jan Willem J Elting
- Department of Neurology, University of Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands; Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands
| | - Deborah Sival
- Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands; Department of Pediatrics, University of Groningen, University Medical Center Groningen, 9700 RB, Groningen, the Netherlands
| | - Corien C Verschuuren-Bemelmans
- Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands; Department of Genetics, University of Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands
| | - Tom J de Koning
- Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands; Department of Genetics, University of Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands; Pediatrics, department of Clinical Sciences, Lund University, 22185 Lund, Sweden
| | - Marina A J Tijssen
- Department of Neurology, University of Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands; Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen, 9700 RB, Groningen, the Netherlands.
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Gonkowski S, Kowalczyk M, Makowska K. Vladislav Dzerzhinsky (1881-1942). Neurol Sci 2024; 45:4601-4603. [PMID: 38963566 PMCID: PMC11306531 DOI: 10.1007/s10072-024-07679-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 06/27/2024] [Indexed: 07/05/2024]
Affiliation(s)
- Sławomir Gonkowski
- Department of Clinical Physiology. Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland
| | | | - Krystyna Makowska
- Department of Clinical Diagnostics, Faculty of Veterinary Medicine, University of Warmia and Mazury, Olsztyn, Poland.
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Pollini L, van der Veen S, Elting JWJ, Tijssen MAJ. Negative Myoclonus: Neurophysiological Study and Clinical Impact in Progressive Myoclonus Ataxia. Mov Disord 2024; 39:674-683. [PMID: 38385661 DOI: 10.1002/mds.29741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 01/13/2024] [Accepted: 01/25/2024] [Indexed: 02/23/2024] Open
Abstract
INTRODUCTION Negative myoclonus (NM) is an involuntary movement caused by a sudden interruption of muscular activity, resulting in gait problems and falls. OBJECTIVE To establish frequency, clinical impact, and neurophysiology of NM in progressive myoclonus ataxia (PMA) patients. METHODS Clinical, neurophysiological, and genetic data of 14 PMA individuals from University Medical Centre Groningen (UMCG) Expertise Center Movement Disorder Groningen were retrospectively collected. Neurophysiological examination included video-electromyography-accelerometry assessment in all patients and electroencephalography (EEG) examination in 13 individuals. Jerk-locked (or silent period-locked) back-averaging and cortico-muscular coherence (CMC) analysis aided the classification of myoclonus. RESULTS NM was present in 6 (NM+) and absent in 8 (NM-) PMA patients. NM+ individuals have more frequent falls (100% vs. 37.5%) and higher scores on the Gross Motor Function Classification System (GMFCS) (4.3 ±0.74 vs. 2.5 ±1.2) than NM- individuals. Genetic background of NM+ included GOSR2 and SEMA6B, while that of NM- included ATM, KCNC3, NUS1, STPBN2, and GOSR2. NM was frequently preceded by positive myoclonus (PM) and silent-period length was between 88 and 194 ms. EEG epileptiform discharges were associated with NM in 2 cases. PM was classified as cortical in 5 NM+ and 2 NM- through EEG inspection, jerk-locked back-averaging, or CMC analysis. DISCUSSION Neurophysiological examination is crucial for detecting NM that could be missed on clinical examination due to a preceding PM. Evidence points to a cortical origin of NM, an association with more severe motor phenotype, and suggests the presence of genetic disorders causing either a PMA or progressive myoclonus epilepsy, rather than pure PMA phenotype. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Luca Pollini
- Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy
- Department of Neurology, University of Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
- Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
| | - Sterre van der Veen
- Department of Neurology, University of Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
- Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
| | - Jan Willem J Elting
- Department of Neurology, University of Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
- Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
- Department of Clinical Neurophysiology, University of Groningen, University Medical Center Groningen (UMCG), Groningen, The Netherlands
| | - Marina A J Tijssen
- Department of Neurology, University of Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
- Expertise Centre Movement Disorders Groningen, University Medical Centre Groningen (UMCG), Groningen, The Netherlands
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Williams LJ, Waller S, Qiu J, Innes E, Elserafy N, Procopis P, Sampaio H, Mahant N, Tchan MC, Mohammad SS, Morales‐Briceño H, Fung VS. DHDDS and NUS1: A Converging Pathway and Common Phenotype. Mov Disord Clin Pract 2024; 11:76-85. [PMID: 38291835 PMCID: PMC10828623 DOI: 10.1002/mdc3.13920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 08/11/2023] [Accepted: 10/23/2023] [Indexed: 02/01/2024] Open
Abstract
BACKGROUND Variants in dehydrodolichol diphosphate synthetase (DHDDS) and nuclear undecaprenyl pyrophosphate synthase 1 (NUS1) cause a neurodevelopmental disorder, classically with prominent epilepsy. Recent reports suggest a complex movement disorder and an overlapping phenotype has been postulated due to their combined role in dolichol synthesis. CASES We describe three patients with heterozygous variants in DHDDS and five with variants affecting NUS1. They bear a remarkably similar phenotype of a movement disorder dominated by multifocal myoclonus. Diagnostic clues include myoclonus exacerbated by action and facial involvement, and slowly progressive or stable, gait ataxia with disproportionately impaired tandem gait. Myoclonus is confirmed with neurophysiology, including EMG of facial muscles. LITERATURE REVIEW Ninety-eight reports of heterozygous variants in DHDDS, NUS1 and chromosome 6q22.1 structural alterations spanning NUS1, confirm the convergent phenotype of hypotonia at birth, developmental delay, multifocal myoclonus, ataxia, dystonia and later parkinsonism with or without generalized epilepsy. Other features include periodic exacerbations, stereotypies, anxiety, and dysmorphisms. Although their gene products contribute to dolichol biosynthesis, a key step in N-glycosylation, transferrin isoform profiles are typically normal. Imaging is normal or non-specific. CONCLUSIONS Recognition of their shared phenotype may expedite diagnosis through chromosomal microarray and by including DHDDS/NUS1 in movement disorder gene panels.
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Affiliation(s)
- Laura J. Williams
- Movement Disorder Unit, Department of NeurologyWestmead HospitalWestmeadNew South WalesAustralia
| | - Sophie Waller
- Movement Disorder Unit, Department of NeurologyWestmead HospitalWestmeadNew South WalesAustralia
| | - Jessica Qiu
- Movement Disorder Unit, Department of NeurologyWestmead HospitalWestmeadNew South WalesAustralia
| | - Emily Innes
- TY Nelson Department of Neurology and NeurosurgeryThe Children's Hospital at WestmeadWestmeadNew South WalesAustralia
- School of Medicine SydneyThe University of Notre DameSydneyNew South WalesAustralia
| | - Noha Elserafy
- Department of Genomic MedicineWestmead HospitalWestmeadNew South WalesAustralia
| | - Peter Procopis
- TY Nelson Department of Neurology and NeurosurgeryThe Children's Hospital at WestmeadWestmeadNew South WalesAustralia
- The Children's Hospital at Westmead Clinical School, Faculty of Medicine and HealthUniversity of SydneySydneyNew South WalesAustralia
| | - Hugo Sampaio
- Department of NeurologySydney Children's HospitalRandwickNew South WalesAustralia
- School of Women's and Children's HealthUniversity of New South WalesSydneyNew South WalesAustralia
| | - Neil Mahant
- Movement Disorder Unit, Department of NeurologyWestmead HospitalWestmeadNew South WalesAustralia
| | - Michel C. Tchan
- Department of Genomic MedicineWestmead HospitalWestmeadNew South WalesAustralia
- Specialty of Genomic Medicine, Faculty of Medicine and HealthThe University of SydneySydneyNew South WalesAustralia
| | - Shekeeb S. Mohammad
- TY Nelson Department of Neurology and NeurosurgeryThe Children's Hospital at WestmeadWestmeadNew South WalesAustralia
- Kids Neuroscience CentreThe Children's Hospital at WestmeadWestmeadNew South WalesAustralia
- Sydney Medical School, Faculty of Medicine and HealthUniversity of SydneySydneyNew South WalesAustralia
| | - Hugo Morales‐Briceño
- Movement Disorder Unit, Department of NeurologyWestmead HospitalWestmeadNew South WalesAustralia
| | - Victor S.C. Fung
- Movement Disorder Unit, Department of NeurologyWestmead HospitalWestmeadNew South WalesAustralia
- Sydney Medical School, Faculty of Medicine and HealthUniversity of SydneySydneyNew South WalesAustralia
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Ji C, Zhao J, Zhang J, Wang K. Novel NUS1 variant in a Chinese patient with progressive myoclonus epilepsy: a case report and systematic review. Neurol Sci 2023; 44:3495-3498. [PMID: 37249665 DOI: 10.1007/s10072-023-06851-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 05/10/2023] [Indexed: 05/31/2023]
Abstract
BACKGROUND Variants of the NUS1 gene have been associated with an extensive spectrum of phenotypes, including epilepsy, intellectual disability, cerebellar ataxia, Parkinson's disease, dystonia, and congenital disorder of glycosylation. It is rarely reported in progressive myoclonus epilepsy (PME). METHODS AND RESULTS Herein, we report the case of PME caused by a novel de novo NUS1 missense variant (c.302T>A, p.Met101Lys). In addition, we reviewed the current literature of NUS1-associated PME. At present, five patients with NUS1 variants and PME have been reported in the literature. Due to limited cases reported, the relationship between NUS1 variants and PME is not well-established. CONCLUSIONS Our case provides further evidence of the role of NUS1 variants in PME. These findings expand the clinical phenotypes of NUS1 variants, which should be included in the PME genetic screening panel.
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Affiliation(s)
- Caihong Ji
- Epilepsy Center, Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, No. 79 Qingchun Road, Hangzhou, 310003, China
| | - Jiajia Zhao
- Epilepsy Center, Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, No. 79 Qingchun Road, Hangzhou, 310003, China
| | - Jianfang Zhang
- Epilepsy Center, Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, No. 79 Qingchun Road, Hangzhou, 310003, China
| | - Kang Wang
- Epilepsy Center, Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, No. 79 Qingchun Road, Hangzhou, 310003, China.
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Van Der Veen S, Tijssen MAJ, Berkovic SF. The Muddle of Myoclonus: Many Guises, 2 Disciplines, Consensus Needed. Neurol Clin Pract 2023; 13:e200187. [PMID: 37664134 PMCID: PMC10473854 DOI: 10.1212/cpj.0000000000200187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 07/18/2023] [Indexed: 09/05/2023]
Abstract
Myoclonus is often approached in different ways by epileptologists and movement disorder specialists, leading to confusion in the literature. Multiplicity and inconsistency over the past 2 centuries resulted in a lack of precision and ambiguity of the terminology. We show that this is a current problem in which one phenomenon has been described with many terms and vice versa. Of more importance, we discuss the conceptualization of myoclonus from perspectives of both fields and focus on the borderland that exists, especially in the spectrum of cortical and epileptic myoclonus. By giving 2 examples, we illustrate the conundrum: the spectrum of progressive myoclonus epilepsies and progressive myoclonic ataxias and "cortical tremor" observed in familial cortical myoclonic tremor with epilepsy or familial adult myoclonic epilepsy. We attempt to facilitate to bridge these subspecialties and form the base for a uniform understanding to take this issue forward toward future classifications, discussions, and scientific research.
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Affiliation(s)
- Sterre Van Der Veen
- Department of Neurology (SVDV, MAJT), University of Groningen, University Medical Centre Groningen; Expertise Centre Movement Disorders Groningen (SVDV, MAJT), University Medical Centre Groningen; and Epilepsy Research Centre (SVDV, SFB), Department of Medicine, University of Melbourne, Austin Health
| | - Marina A J Tijssen
- Department of Neurology (SVDV, MAJT), University of Groningen, University Medical Centre Groningen; Expertise Centre Movement Disorders Groningen (SVDV, MAJT), University Medical Centre Groningen; and Epilepsy Research Centre (SVDV, SFB), Department of Medicine, University of Melbourne, Austin Health
| | - Samuel F Berkovic
- Department of Neurology (SVDV, MAJT), University of Groningen, University Medical Centre Groningen; Expertise Centre Movement Disorders Groningen (SVDV, MAJT), University Medical Centre Groningen; and Epilepsy Research Centre (SVDV, SFB), Department of Medicine, University of Melbourne, Austin Health
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Teive HAG, Cassou E, Coutinho L, Camargo CHF, Munhoz RP. Ramsay Hunt syndrome: New impressions in the era of molecular genetics. Parkinsonism Relat Disord 2022; 97:101-104. [PMID: 35430109 DOI: 10.1016/j.parkreldis.2022.04.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/22/2022] [Accepted: 04/04/2022] [Indexed: 11/27/2022]
Abstract
More frequent use of next-generation sequencing led to a paradigm shift in assessing heredodegenerative diseases. This is particularly notable in progressive myoclonus epilepsy (PME) and progressive myoclonus ataxia (PMA) where a group of disorders linked to novel genetic mutations has now been added to these phenotypical realms. Despite the historical value of Ramsay Hunt's contribution defining the syndrome later known as PMA, recent genetic developments have made this eponym obsolete and a new definition and classification of PMA and PME seem necessary. A rational possibility is to adopt the wider term progressive myoclonus ataxia and epilepsy syndrome (PMAES), which can be subdivided into its main subtypes, PME and PMA, whenever clinical data is sufficient to make that distinction.
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Affiliation(s)
- Hélio A G Teive
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná, Curitiba, Paraná, Brazil; Neurodegenerative Diseases Group, Postgraduate Program in Internal Medicine, Hospital de Clínicas, Federal University of Paraná, Curitiba, Paraná, Brazil.
| | - Emanuel Cassou
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná, Curitiba, Paraná, Brazil.
| | - Léo Coutinho
- Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Federal University of Paraná, Curitiba, Paraná, Brazil.
| | - Carlos Henrique F Camargo
- Neurodegenerative Diseases Group, Postgraduate Program in Internal Medicine, Hospital de Clínicas, Federal University of Paraná, Curitiba, Paraná, Brazil.
| | - Renato P Munhoz
- Movement Disorders Centre, Toronto Western Hospital, University of Toronto, Toronto, Ontario, Canada.
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Burton MA, Dalrymple WA, Figari R. Assessment and Treatment of Myoclonus: A Review. Neurology 2022. [DOI: 10.17925/usn.2022.18.1.38] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Myoclonus is defined as sudden, brief, shock-like contractions of muscles, and it can be a challenging diagnosis for the clinician to face. The number of aetiologies can make it difficult to determine the appropriate diagnostic workup for each individual patient without ordering a broad array of diagnostic studies from the start. As with other neurological conditions, a comprehensive history and physical examination are paramount in generating and ordering the initial differential diagnosis. Neurophysiological classification of myoclonus, using both electroencephalogram and electromyography, can be very helpful in elucidating the underlying aetiology. Treatment of myoclonus is often symptomatic, unless a clear treatable underlying cause can be found. This article aims to help providers navigate the assessment and treatment of myoclonus, focusing on neurophysiological classification as a guide. By the end of this article, providers should have a good understanding of how to approach the workup and treatment of myoclonus of various aetiologies.
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Pollini L, Tijssen MAJ. A diagnosis of progressive myoclonic ataxia guided by blood biomarkers: Expert commentary. Parkinsonism Relat Disord 2021; 94:127-128. [PMID: 34896024 DOI: 10.1016/j.parkreldis.2021.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/01/2021] [Accepted: 12/02/2021] [Indexed: 11/25/2022]
Affiliation(s)
- L Pollini
- Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy; Expertise Centre Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Neurology, University Medical Centre Groningen, Groningen, the Netherlands
| | - M A J Tijssen
- Expertise Centre Movement Disorders Groningen, University Medical Center Groningen, Groningen, the Netherlands; Department of Neurology, University Medical Centre Groningen, Groningen, the Netherlands.
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Abstract
Movement disorders presenting in childhood include tics, dystonia, chorea, tremor, stereotypy, myoclonus, and parkinsonism, each of which can be part of various clinical syndromes with distinct etiologies. Some of these conditions are benign and require only reassurance; others are bothersome and require treatment, or may be clues that herald underlying pathology. Answers lie in the inherent characteristics of the movements themselves, together with the clinical context provided in the history obtained by the examiner. The aim of this review is to present an overview of the categories of involuntary movements, along with examples of common acquired and genetic causes, and an approach to history-taking, examination, and treatment.
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Affiliation(s)
- Joanna Blackburn
- Division of Child Neurology, Ann & Robert H. Lurie Children's Hospital of Chicago, Northwestern Feinberg School of Medicine, Chicago, IL, United States
| | - Mered Parnes
- Pediatric Movement Disorders Clinic, Section of Pediatric Neurology and Developmental Neuroscience, Texas Children's Hospital and Baylor College of Medicine, Houston, TX, United States.
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