1
|
Bhatia K, Balint B. Autoimmunity Panels: Needs and Implementation in the Underdeveloped Regions and how to Approach the Disparities. Mov Disord Clin Pract 2024; 11:119-122. [PMID: 38386486 PMCID: PMC10883400 DOI: 10.1002/mdc3.13946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 11/15/2023] [Accepted: 11/15/2023] [Indexed: 02/24/2024] Open
|
2
|
Araújo R, Fearon C, Balint B, Bressman S, Friedman J, Jinnah HA, Tijssen MAJ, Lang A, Lees A, Lynch T, Quinn N, Thomson P, Vidailhet M, van de Warrenburg BP, Fung VSC, Bloem BR. The wisdom of our mentors: clinical pearls in movement disorders. Lancet Neurol 2023; 22:1108-1109. [PMID: 37977708 DOI: 10.1016/s1474-4422(23)00422-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
|
3
|
Efthymiou E, Baumann CR, Balint B. The Expanding Field of Autoimmune Sleep-Wake Disorders-Implications for the Movement Disorders Clinical Practice. Mov Disord Clin Pract 2023; 10:1476-1477. [PMID: 37868921 PMCID: PMC10585957 DOI: 10.1002/mdc3.13869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 06/13/2023] [Accepted: 08/01/2023] [Indexed: 10/24/2023] Open
|
4
|
Vlad B, Wang Y, Newsome SD, Balint B. Stiff Person Spectrum Disorders-An Update and Outlook on Clinical, Pathophysiological and Treatment Perspectives. Biomedicines 2023; 11:2500. [PMID: 37760941 PMCID: PMC10525659 DOI: 10.3390/biomedicines11092500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 09/06/2023] [Accepted: 09/07/2023] [Indexed: 09/29/2023] Open
Abstract
Stiff person spectrum disorders (SPSD) are paradigm autoimmune movement disorders characterized by stiffness, spasms and hyperekplexia. Though rare, SPSD represent a not-to-miss diagnosis because of the associated disease burden and treatment implications. After decades as an enigmatic orphan disease, major advances in our understanding of the evolving spectrum of diseases have been made along with the identification of multiple associated autoantibodies. However, the most important recent developments relate to the recognition of a wider affection, beyond the classic core motor symptoms, and to further insights into immunomodulatory and symptomatic therapies. In this review, we summarize the recent literature on the clinical and paraclinical spectrum, current pathophysiological understanding, as well as current and possibly future therapeutic strategies.
Collapse
|
5
|
Balint B. Relevance of Antibody Testing in Movement Disorders. Mov Disord Clin Pract 2023; 10:S32-S35. [PMID: 37637987 PMCID: PMC10448132 DOI: 10.1002/mdc3.13772] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 05/03/2023] [Accepted: 05/04/2023] [Indexed: 08/29/2023] Open
|
6
|
Vlad B, Jelcic I, Balint B. Parkinsonism due to Coxsackie B Virus Infection-Case Report and Literature Review. Mov Disord Clin Pract 2023; 10:S24-S28. [PMID: 37636219 PMCID: PMC10448620 DOI: 10.1002/mdc3.13773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 03/15/2023] [Accepted: 05/03/2023] [Indexed: 08/29/2023] Open
|
7
|
Balint B. Isolated dystonia with
NMDAR
antibodies: expanding the phenotype or illustrating the intricacies of antibody testing? Mov Disord Clin Pract 2023; 10:677-679. [PMID: 37070035 PMCID: PMC10105097 DOI: 10.1002/mdc3.13709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/19/2023] [Indexed: 03/06/2023] Open
|
8
|
Gövert F, Abrante L, Becktepe J, Balint B, Ganos C, Hofstadt-van Oy U, Krogias C, Varley J, Irani SR, Paneva S, Titulaer MJ, de Vries JM, Boon AJW, Schreurs MWJ, Joubert B, Honnorat J, Vogrig A, Ariño H, Sabater L, Dalmau J, Scotton S, Jacob S, Melzer N, Bien CG, Geis C, Lewerenz J, Prüss H, Wandinger KP, Deuschl G, Leypoldt F. Distinct movement disorders in contactin-associated-protein-like-2 antibody-associated autoimmune encephalitis. Brain 2023; 146:657-667. [PMID: 35875984 DOI: 10.1093/brain/awac276] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 06/02/2022] [Accepted: 06/22/2022] [Indexed: 11/14/2022] Open
Abstract
Autoimmune encephalitis can be classified into antibody-defined subtypes, which can manifest with immunotherapy-responsive movement disorders sometimes mimicking non-inflammatory aetiologies. In the elderly, anti-LGI1 and contactin associated protein like 2 (CASPR2) antibody-associated diseases compose a relevant fraction of autoimmune encephalitis. Patients with LGI1 autoantibodies are known to present with limbic encephalitis and additionally faciobrachial dystonic seizures may occur. However, the clinical spectrum of CASPR2 autoantibody-associated disorders is more diverse including limbic encephalitis, Morvan's syndrome, peripheral nerve hyperexcitability syndrome, ataxia, pain and sleep disorders. Reports on unusual, sometimes isolated and immunotherapy-responsive movement disorders in CASPR2 autoantibody-associated syndromes have caused substantial concern regarding necessity of autoantibody testing in patients with movement disorders. Therefore, we aimed to systematically assess their prevalence and manifestation in patients with CASPR2 autoimmunity. This international, retrospective cohort study included patients with CASPR2 autoimmunity from participating expert centres in Europe. Patients with ataxia and/or movement disorders were analysed in detail using questionnaires and video recordings. We recruited a comparator group with anti-LGI1 encephalitis from the GENERATE network. Characteristics were compared according to serostatus. We identified 164 patients with CASPR2 autoantibodies. Of these, 149 (90.8%) had only CASPR2 and 15 (9.1%) both CASPR2 and LGI1 autoantibodies. Compared to 105 patients with LGI1 encephalitis, patients with CASPR2 autoantibodies more often had movement disorders and/or ataxia (35.6 versus 3.8%; P < 0.001). This was evident in all subgroups: ataxia 22.6 versus 0.0%, myoclonus 14.6 versus 0.0%, tremor 11.0 versus 1.9%, or combinations thereof 9.8 versus 0.0% (all P < 0.001). The small group of patients double-positive for LGI1/CASPR2 autoantibodies (15/164) significantly more frequently had myoclonus, tremor, 'mixed movement disorders', Morvan's syndrome and underlying tumours. We observed distinct movement disorders in CASPR2 autoimmunity (14.6%): episodic ataxia (6.7%), paroxysmal orthostatic segmental myoclonus of the legs (3.7%) and continuous segmental spinal myoclonus (4.3%). These occurred together with further associated symptoms or signs suggestive of CASPR2 autoimmunity. However, 2/164 patients (1.2%) had isolated segmental spinal myoclonus. Movement disorders and ataxia are highly prevalent in CASPR2 autoimmunity. Paroxysmal orthostatic segmental myoclonus of the legs is a novel albeit rare manifestation. Further distinct movement disorders include isolated and combined segmental spinal myoclonus and autoimmune episodic ataxia.
Collapse
|
9
|
Koens LH, Klamer MR, Sival DA, Balint B, Bhatia KP, Contarino MF, van Egmond ME, Erro R, Friedman J, Fung VSC, Ganos C, Kurian MA, Lang AE, McGovern EM, Roze E, de Koning TJ, Tijssen MAJ. A Screening Tool to Quickly Identify Movement Disorders in Patients with Inborn Errors of Metabolism. Mov Disord 2023; 38:646-653. [PMID: 36727539 DOI: 10.1002/mds.29332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 12/12/2022] [Accepted: 12/22/2022] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Movement disorders are frequent in patients with inborn errors of metabolism (IEMs) but poorly recognized, particularly by nonmovement disorder specialists. We propose an easy-to-use clinical screening tool to help recognize movement disorders. OBJECTIVE The aim is to develop a user-friendly rapid screening tool for nonmovement disorder specialists to detect moderate and severe movement disorders in patients aged ≥4 years with IEMs. METHODS Videos of 55 patients with different IEMs were scored by experienced movement disorder specialists (n = 12). Inter-rater agreements were determined on the presence and subtype of the movement disorder. Based on ranking and consensus, items were chosen to be incorporated into the screening tool. RESULTS A movement disorder was rated as present in 80% of the patients, with a moderate inter-rater agreement (κ =0.420, P < 0.001) on the presence of a movement disorder. When considering only moderate and severe movement disorders, the inter-rater agreement increased to almost perfect (κ = 0.900, P < 0.001). Dystonia was most frequently scored (27.3%) as the dominant phenotype. Treatment was mainly suggested for patients with moderate or severe movement disorders. Walking, observations of the arms, and drawing a spiral were found to be the most informative tasks and were included in the screening tool. CONCLUSIONS We designed a screening tool to recognize movement disorders in patients with IEMs. We propose that this screening tool can contribute to select patients who should be referred to a movement disorder specialist for further evaluation and, if necessary, treatment of the movement disorder. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Collapse
|
10
|
Macías‐García D, Balint B. Disentangling the phenotypes of
anti‐IgLON5
disease: when clinical suspicion matters. Mov Disord Clin Pract 2022; 9:456-457. [PMID: 35586538 PMCID: PMC9092746 DOI: 10.1002/mdc3.13446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 03/08/2022] [Indexed: 11/05/2022] Open
|
11
|
Mulroy E, Balint B, Bhatia KP. Homer-3 Antibody Disease: A Potentially Treatable MSA-C Mimic. Mov Disord Clin Pract 2022; 9:178-182. [PMID: 35146057 PMCID: PMC8810419 DOI: 10.1002/mdc3.13404] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/19/2021] [Accepted: 12/21/2021] [Indexed: 01/11/2023] Open
|
12
|
Magrinelli F, Mehta S, Di Lazzaro G, Latorre A, Edwards MJ, Balint B, Basu P, Kobylecki C, Groppa S, Hegde A, Mulroy E, Estevez-Fraga C, Arora A, Kumar H, Schneider SA, Lewis PA, Jaunmuktane Z, Revesz T, Gandhi S, Wood NW, Hardy JA, Tinazzi M, Lal V, Houlden H, Bhatia KP. Dissecting the Phenotype and Genotype of PLA2G6-Related Parkinsonism. Mov Disord 2022; 37:148-161. [PMID: 34622992 DOI: 10.1002/mds.28807] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 08/31/2021] [Accepted: 09/13/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Complex parkinsonism is the commonest phenotype in late-onset PLA2G6-associated neurodegeneration. OBJECTIVES The aim of this study was to deeply characterize phenogenotypically PLA2G6-related parkinsonism in the largest cohort ever reported. METHODS We report 14 new cases of PLA2G6-related parkinsonism and perform a systematic literature review. RESULTS PLA2G6-related parkinsonism shows a fairly distinct phenotype based on 86 cases from 68 pedigrees. Young onset (median age, 23.0 years) with parkinsonism/dystonia, gait/balance, and/or psychiatric/cognitive symptoms were common presenting features. Dystonia occurred in 69.4%, pyramidal signs in 77.2%, myoclonus in 65.2%, and cerebellar signs in 44.6% of cases. Early bladder overactivity was present in 71.9% of cases. Cognitive impairment affected 76.1% of cases and psychiatric features 87.1%, the latter being an isolated presenting feature in 20.1%. Parkinsonism was levodopa responsive but complicated by early, often severe dyskinesias. Five patients benefited from deep brain stimulation. Brain magnetic resonance imaging findings included cerebral (49.3%) and/or cerebellar (43.2%) atrophy, but mineralization was evident in only 28.1%. Presynaptic dopaminergic terminal imaging was abnormal in all where performed. Fifty-four PLA2G6 mutations have hitherto been associated with parkinsonism, including four new variants reported in this article. These are mainly nontruncating, which may explain the phenotypic heterogeneity of childhood- and late-onset PLA2G6-associated neurodegeneration. In five deceased patients, median disease duration was 13.0 years. Brain pathology in three cases showed mixed Lewy and tau pathology. CONCLUSIONS Biallelic PLA2G6 mutations cause early-onset parkinsonism associated with dystonia, pyramidal and cerebellar signs, myoclonus, and cognitive impairment. Early psychiatric manifestations and bladder overactivity are common. Cerebro/cerebellar atrophy are frequent magnetic resonance imaging features, whereas brain iron deposition is not. Early, severe dyskinesias are a tell-tale sign. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Collapse
|
13
|
Balint B, Bhatia KP, Dalmau J. Reply to: Comparing VUS and AUS: Parallels and Differences in Neurogenetics and Neuroimmunology. Mov Disord 2021; 36:2454-2456. [PMID: 34658066 DOI: 10.1002/mds.28764] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 08/03/2021] [Indexed: 11/08/2022] Open
|
14
|
De Rosa A, Balint B, Kumar KR. Editorial: Genetics of Paroxysmal Movement Disorders. Front Neurol 2021; 12:752000. [PMID: 34650515 PMCID: PMC8505715 DOI: 10.3389/fneur.2021.752000] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 08/18/2021] [Indexed: 12/05/2022] Open
|
15
|
Morales-Briceno H, Fung VSC, Bhatia KP, Balint B. Parkinsonism and dystonia: Clinical spectrum and diagnostic clues. J Neurol Sci 2021; 433:120016. [PMID: 34642024 DOI: 10.1016/j.jns.2021.120016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 08/20/2021] [Accepted: 09/29/2021] [Indexed: 10/20/2022]
Abstract
The links between the two archetypical basal ganglia disorders, dystonia and parkinsonism, are manifold and stem from clinical observations, imaging studies, animal models and genetics. The combination of both, i.e. the syndrome of dystonia-parkinsonism, is not uncommonly seen in movement disorders clinics and has a myriad of different underlying aetiologies, upon which treatment and prognosis depend. Based on a comprehensive literature review, we delineate the clinical spectrum of disorders presenting with dystonia-parkinsonism. The clinical approach depends primarily on the age at onset, associated neurological or systemic symptoms and neuroimaging. The tempo of disease progression, and the response to L-dopa are further important clues to tailor diagnostic approaches that may encompass dopamine transporter imaging, CSF analysis and, last but not least, genetic testing. Later in life, sporadic neurodegenerative conditions are the most frequent cause, but the younger the patient, the more likely the cause is unravelled by the recent advances of molecular genetics that are focus of this review. Here, knowledge of the associated phenotypic spectrum is key to guide genetic testing and interpretation of test results. This article is part of the Special Issue "Parkinsonism across the spectrum of movement disorders and beyond" edited by Joseph Jankovic, Daniel D. Truong and Matteo Bologna.
Collapse
|
16
|
Balint B, Ogawa T, Ogaki K, Daida K, Nishimaki T, Ando M, Kawajiri S, Wada R, Noda K, Hattori N, Okuma Y, Barsottini O. Commentary: Progressive Encephalomyelitis with Rigidity and Myoclonus and Myasthenia Gravis Comorbid Status with Thymoma. Mov Disord Clin Pract 2021; 8:S14-S15. [PMID: 34514037 PMCID: PMC8414491 DOI: 10.1002/mdc3.13303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 06/04/2021] [Indexed: 11/10/2022] Open
|
17
|
Fasano A, Prakash P, Bledsoe IO, Balint B. Commentary: Paraneoplastic Syndrome Associated with Kelch-Like Protein 11 Antibodies Presenting with Progressive Ataxia and Tremor. Mov Disord Clin Pract 2021; 8:S45-S46. [PMID: 34514049 PMCID: PMC8414493 DOI: 10.1002/mdc3.13300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Accepted: 05/28/2021] [Indexed: 11/09/2022] Open
|
18
|
Balint B, Bhatia KP, Dalmau J. "Antibody of Unknown Significance" (AUS): The Issue of Interpreting Antibody Test Results. Mov Disord 2021; 36:1543-1547. [PMID: 33955060 DOI: 10.1002/mds.28597] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 01/30/2021] [Accepted: 03/05/2021] [Indexed: 11/11/2022] Open
|
19
|
Balint B, Mulroy E, Gövert F, Latorre A, Di Lazarro G, Erro R, Batla A, Holton JL, Miki Y, Warner TT, Bhatia KP. Development of parkinsonism after long-standing cervical dystonia - A cohort. J Neurol Sci 2021; 427:117477. [PMID: 34015516 DOI: 10.1016/j.jns.2021.117477] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Revised: 04/27/2021] [Accepted: 05/02/2021] [Indexed: 12/27/2022]
Abstract
INTRODUCTION Dystonia occurring in the context of parkinsonism is well-known, e.g. as foot dystonia in young-onset Parkinson's disease (PD), anterocollis in multisystem atrophy (MSA) or blepharospasm (levator inhibition) in progressive supranuclear palsy. We have, however, encountered a series of patients whose phenotype differed from the above described entities. METHODS We describe a cohort of patients in whom typical idiopathic isolated (primary) late-onset focal or segmental (predominantly cervical) dystonia preceded the development of parkinsonism by several years, sometimes decades. RESULTS In a cohort of 450 patients followed in our botulinum toxin injections clinic, we identified 11 (2.4%; 7 women) who developed parkinsonism at a median of 14 years after the onset of dystonia. Median age at onset of parkinsonism was 70 years (range 59-87), usually manifesting with a new tremor or a change of tremor pattern, complaints of 'slowing down' or new walking difficulties. Parkinsonism resembled PD in 5 (one pathologically confirmed); the remainder had atypical parkinsonism of MSA (n = 3) or indeterminate phenotype (n = 3). CONCLUSION The relatively frequent occurrence of parkinsonism after long-standing dystonia would suggest a link between the two, in line with evidence from other clinical reports, imaging studies, animal models and genetics. It appears that in some cases of dystonia this could be an antecedent manifestation of a syndrome with parkinsonism developing later, or be a risk factor for parkinsonism. In practice, it is important for clinicians to be alert to new symptoms/signs in patients with long-standing dystonia. From a research point of view, longitudinal case-control studies would be required to further investigate the link between long-standing dystonia and subsequent parkinsonism.
Collapse
|
20
|
Gatto EM, Walker RH, Gonzalez C, Cesarini M, Cossu G, Stephen CD, Balint B, Rodríguez-Violante M, Jankovic J, Morgante F, Jinnah HA. Worldwide barriers to genetic testing for movement disorders. Eur J Neurol 2021; 28:1901-1909. [PMID: 33730413 DOI: 10.1111/ene.14826] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Revised: 03/08/2021] [Accepted: 03/12/2021] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND PURPOSE Despite enormous advances in identifying genetic variants responsible for many neurological diseases, access to genetic testing may be limited in clinical practice. The objective of this study was to assess worldwide access to genetic tests for movement disorders and factors impacting their utilization. METHODS The Rare Movement Disorders Study Group of the International Parkinson and Movement Disorder Society designed an online survey electronically mailed to all 7815 members. RESULTS Survey data completed by 1269 participants from 109 countries were analysed. Limited access to geneticists and genetic counsellors was reported in many world regions compared to Europe and North America. Availability of genetic testing was limited, with rates of access lower than 50%. Genetic testing for chorea was the most commonly available. For parkinsonism, dystonia, ataxia, hereditary spastic paraplegias and metabolic disorders, there was limited access to genetic testing in all countries compared to Europe and North America, with significant differences found for Africa, Central/South America, Asia. In many regions, genetic testing was supported by either private or public funding. Genetic testing was free of charge in Europe according to 63.5% of respondents. In North America, Africa, Central/South America, Asia and the Middle East access to free of charge genetic testing was by far significantly lower compared to Europe. CONCLUSIONS This survey highlights difficulties in accessing genetic testing and individuals with expertise in genetics at the worldwide level. In addition, major disparities in genetic testing amongst world regions are highlighted, probably due to a variety of factors including financial barriers.
Collapse
|
21
|
Balint B. Are Antibody Panels Under-Utilized in Movement Disorders Diagnosis? Yes. Mov Disord Clin Pract 2021; 8:341-346. [PMID: 33816660 PMCID: PMC8015910 DOI: 10.1002/mdc3.13171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 01/24/2021] [Accepted: 01/26/2021] [Indexed: 11/21/2022] Open
|
22
|
Magrinelli F, Balint B, Bhatia KP. Challenges in Clinicogenetic Correlations: One Gene - Many Phenotypes. Mov Disord Clin Pract 2021; 8:299-310. [PMID: 33816657 PMCID: PMC8015894 DOI: 10.1002/mdc3.13165] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 12/02/2020] [Accepted: 12/19/2020] [Indexed: 12/25/2022] Open
Abstract
Background Progress in genetics – particularly the advent of next‐generation sequencing (NGS) – has enabled an unparalleled gene discovery and revealed unmatched complexity of genotype–phenotype correlations in movement disorders. Among other things, it has emerged that mutations in one and the same gene can cause multiple, often markedly different phenotypes. Consequently, movement disorder specialists have increasingly experienced challenges in clinicogenetic correlations. Objectives To deconstruct biological phenomena and mechanistic bases of phenotypic heterogeneity in monogenic movement disorders and neurodegenerative diseases. To discuss the evolving role of movement disorder specialists in reshaping disease phenotypes in the NGS era. Methods This scoping review details phenomena contributing to phenotypic heterogeneity and their underlying mechanisms. Results Three phenomena contribute to phenotypic heterogeneity, namely incomplete penetrance, variable expressivity and pleiotropy. Their underlying mechanisms, which are often shared across phenomena and non‐mutually exclusive, are not fully elucidated. They involve genetic factors (ie, different mutation types, dynamic mutations, somatic mosaicism, intragenic intra‐ and inter‐allelic interactions, modifiers and epistatic genes, mitochondrial heteroplasmy), epigenetic factors (ie, genomic imprinting, X‐chromosome inactivation, modulation of genetic and chromosomal defects), and environmental factors. Conclusion Movement disorders is unique in its reliance on clinical judgment to accurately define disease phenotypes. This has been reaffirmed by the NGS revolution, which provides ever‐growing sequencing data and fuels challenges in variant pathogenicity assertions for such clinically heterogeneous disorders. Deep phenotyping, with characterization and continual updating of “core” phenotypes, and comprehension of determinants of genotype–phenotype complex relationships are crucial for clinicogenetic correlations and have implications for the diagnosis, treatment and counseling.
Collapse
|
23
|
Becktepe J, Gövert F, Balint B, Schlenstedt C, Bhatia K, Elble R, Deuschl G. Exploring Interrater Disagreement on Essential Tremor Using a Standardized Tremor Elements Assessment. Mov Disord Clin Pract 2021; 8:371-376. [PMID: 33816665 PMCID: PMC8015892 DOI: 10.1002/mdc3.13150] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 11/25/2022] Open
Abstract
Background Patients with upper limb action tremor frequently exhibit additional neurological signs of uncertain significance. Clinicians vary in their interpretation, and interrater agreement on the final diagnosis is poor. Objectives A new clinical tool for assessing the presence or absence of clinical signs that are important in axis‐1 classification of tremor patients is introduced: the Standardized Tremor Elements Assessment (STEA). Interrater agreement is determined, and signs leading to disagreement in the final diagnosis are identified. Methods Three tremor‐focussed and one dystonia‐focussed movement disorder specialists rated 59 videos of patients with upper limb action tremor syndromes using STEA. Interrater agreements for final diagnosis and STEA items were calculated. Results Interrater agreement regarding the final diagnosis was higher within the group of tremor specialists and poor between dystonia and tremor specialists. Greater agreement was found for items characterizing tremor than for signs of dystonia. Conclusions Clinical signs leading to diagnostic disagreement were identified with STEA, and STEA should therefore be useful in future studies of diagnostic disagreement. The thresholds for considering neurological signs as soft versus significant for ataxia, parkinsonism, dystonia, etc. are critically important in tremor classification and must be studied across movement disorder subspecialties, not simply within a pool of tremor specialists.
Collapse
|
24
|
Mencacci NE, Brockmann MM, Dai J, Pajusalu S, Atasu B, Campos J, Pino G, Gonzalez-Latapi P, Patzke C, Schwake M, Tucci A, Pittman A, Simon-Sanchez J, Carvill GL, Balint B, Wiethoff S, Warner TT, Papandreou A, Soo A, Rein R, Kadastik-Eerme L, Puusepp S, Reinson K, Tomberg T, Hanagasi H, Gasser T, Bhatia KP, Kurian MA, Lohmann E, Õunap K, Rosenmund C, Südhof TC, Wood NW, Krainc D, Acuna C. Biallelic variants in TSPOAP1, encoding the active-zone protein RIMBP1, cause autosomal recessive dystonia. J Clin Invest 2021; 131:140625. [PMID: 33539324 DOI: 10.1172/jci140625] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 02/03/2021] [Indexed: 12/27/2022] Open
Abstract
Dystonia is a debilitating hyperkinetic movement disorder, which can be transmitted as a monogenic trait. Here, we describe homozygous frameshift, nonsense, and missense variants in TSPOAP1, which encodes the active-zone RIM-binding protein 1 (RIMBP1), as a genetic cause of autosomal recessive dystonia in 7 subjects from 3 unrelated families. Subjects carrying loss-of-function variants presented with juvenile-onset progressive generalized dystonia, associated with intellectual disability and cerebellar atrophy. Conversely, subjects carrying a pathogenic missense variant (p.Gly1808Ser) presented with isolated adult-onset focal dystonia. In mice, complete loss of RIMBP1, known to reduce neurotransmission, led to motor abnormalities reminiscent of dystonia, decreased Purkinje cell dendritic arborization, and reduced numbers of cerebellar synapses. In vitro analysis of the p.Gly1808Ser variant showed larger spike-evoked calcium transients and enhanced neurotransmission, suggesting that RIMBP1-linked dystonia can be caused by either reduced or enhanced rates of spike-evoked release in relevant neural networks. Our findings establish a direct link between dysfunction of the presynaptic active zone and dystonia and highlight the critical role played by well-balanced neurotransmission in motor control and disease pathogenesis.
Collapse
|
25
|
Cif L, Demailly D, Lin JP, Barwick KE, Sa M, Abela L, Malhotra S, Chong WK, Steel D, Sanchis-Juan A, Ngoh A, Trump N, Meyer E, Vasques X, Rankin J, Allain MW, Applegate CD, Attaripour Isfahani S, Baleine J, Balint B, Bassetti JA, Baple EL, Bhatia KP, Blanchet C, Burglen L, Cambonie G, Seng EC, Bastaraud SC, Cyprien F, Coubes C, d'Hardemare V, Doja A, Dorison N, Doummar D, Dy-Hollins ME, Farrelly E, Fitzpatrick DR, Fearon C, Fieg EL, Fogel BL, Forman EB, Fox RG, Gahl WA, Galosi S, Gonzalez V, Graves TD, Gregory A, Hallett M, Hasegawa H, Hayflick SJ, Hamosh A, Hully M, Jansen S, Jeong SY, Krier JB, Krystal S, Kumar KR, Laurencin C, Lee H, Lesca G, François LL, Lynch T, Mahant N, Martinez-Agosto JA, Milesi C, Mills KA, Mondain M, Morales-Briceno H, Ostergaard JR, Pal S, Pallais JC, Pavillard F, Perrigault PF, Petersen AK, Polo G, Poulen G, Rinne T, Roujeau T, Rogers C, Roubertie A, Sahagian M, Schaefer E, Selim L, Selway R, Sharma N, Signer R, Soldatos AG, Stevenson DA, Stewart F, Tchan M, Verma IC, de Vries BBA, Wilson JL, Wong DA, Zaitoun R, Zhen D, Znaczko A, Dale RC, de Gusmão CM, Friedman J, Fung VSC, King MD, Mohammad SS, Rohena L, Waugh JL, Toro C, Raymond FL, Topf M, Coubes P, Gorman KM, Kurian MA. KMT2B-related disorders: expansion of the phenotypic spectrum and long-term efficacy of deep brain stimulation. Brain 2021; 143:3242-3261. [PMID: 33150406 DOI: 10.1093/brain/awaa304] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/28/2020] [Accepted: 07/13/2020] [Indexed: 12/31/2022] Open
Abstract
Heterozygous mutations in KMT2B are associated with an early-onset, progressive and often complex dystonia (DYT28). Key characteristics of typical disease include focal motor features at disease presentation, evolving through a caudocranial pattern into generalized dystonia, with prominent oromandibular, laryngeal and cervical involvement. Although KMT2B-related disease is emerging as one of the most common causes of early-onset genetic dystonia, much remains to be understood about the full spectrum of the disease. We describe a cohort of 53 patients with KMT2B mutations, with detailed delineation of their clinical phenotype and molecular genetic features. We report new disease presentations, including atypical patterns of dystonia evolution and a subgroup of patients with a non-dystonic neurodevelopmental phenotype. In addition to the previously reported systemic features, our study has identified co-morbidities, including the risk of status dystonicus, intrauterine growth retardation, and endocrinopathies. Analysis of this study cohort (n = 53) in tandem with published cases (n = 80) revealed that patients with chromosomal deletions and protein truncating variants had a significantly higher burden of systemic disease (with earlier onset of dystonia) than those with missense variants. Eighteen individuals had detailed longitudinal data available after insertion of deep brain stimulation for medically refractory dystonia. Median age at deep brain stimulation was 11.5 years (range: 4.5-37.0 years). Follow-up after deep brain stimulation ranged from 0.25 to 22 years. Significant improvement of motor function and disability (as assessed by the Burke Fahn Marsden's Dystonia Rating Scales, BFMDRS-M and BFMDRS-D) was evident at 6 months, 1 year and last follow-up (motor, P = 0.001, P = 0.004, and P = 0.012; disability, P = 0.009, P = 0.002 and P = 0.012). At 1 year post-deep brain stimulation, >50% of subjects showed BFMDRS-M and BFMDRS-D improvements of >30%. In the long-term deep brain stimulation cohort (deep brain stimulation inserted for >5 years, n = 8), improvement of >30% was maintained in 5/8 and 3/8 subjects for the BFMDRS-M and BFMDRS-D, respectively. The greatest BFMDRS-M improvements were observed for trunk (53.2%) and cervical (50.5%) dystonia, with less clinical impact on laryngeal dystonia. Improvements in gait dystonia decreased from 20.9% at 1 year to 16.2% at last assessment; no patient maintained a fully independent gait. Reduction of BFMDRS-D was maintained for swallowing (52.9%). Five patients developed mild parkinsonism following deep brain stimulation. KMT2B-related disease comprises an expanding continuum from infancy to adulthood, with early evidence of genotype-phenotype correlations. Except for laryngeal dysphonia, deep brain stimulation provides a significant improvement in quality of life and function with sustained clinical benefit depending on symptoms distribution.
Collapse
|