Publications by authors named "Solveig Montaut"

6 Publications

  • Page 1 of 1

Biallelic RFC1-expansion in a French multicentric sporadic ataxia cohort.

J Neurol 2021 Mar 5. Epub 2021 Mar 5.

Department of Neurology, Strasbourg University Hospital, 1 avenue Molière, 67098, Strasbourg, France.

Objective: Cerebellar ataxia with neuropathy and vestibular areflexia syndrome (CANVAS) is a recessively inherited multisystem ataxia compromising cerebellar, vestibular, and sensory nerves, which has been associated to a pathogenic AAGGG(n) biallelic expansion repeat in the RFC1 gene. Our objective was to assess its prevalence in a French cohort of patients with idiopathic sporadic late-onset ataxia (ILOA), idiopathic early-onset ataxia (IEOA), or Multiple System Atrophy of Cerebellar type (MSA-C).

Methods: 163 patients were recruited in 3 French tertiary centers: 100 ILOA, 21 IEOA, and 42 patients with possible or probable MSA-C.

Results: A pathogenic biallelic RFC1 AAGGG(n) repeat expansion was found in 15 patients: 15/100 in the ILOA group, but none in the IEOA and MSA-C subgroups. 14/15 patients had a CANVAS phenotype. Only 1/15 had isolated cerebellar ataxia, but also shorter biallelic expansions. Two RFC1 AAGGG(n) alleles were found in 78% of patients with a CANVAS phenotype. In one post-mortem case, the pathophysiological involvement of cerebellum and medullar posterior columns was found.

Conclusion: Our study confirms the genetic heterogeneity of the CANVAS and that RFC1 repeat expansions should be searched for preferentially in case of unexplained ILOA associated with a sensory neuronopathy, but not particularly in patients classified as MSA-C.
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March 2021

Natural History, Phenotypic Spectrum, and Discriminative Features of Multisystemic RFC1 Disease.

Neurology 2021 03 25;96(9):e1369-e1382. Epub 2021 Jan 25.

From the Department of Neurodegenerative Diseases (A.T., S.R., L.S., M. Synofzik), Hertie-Institute for Clinical Brain Research and Center of Neurology, and German Center for Neurodegenerative Diseases (DZNE) (A.T., S.R., L.S., M. Synofzik), University of Tübingen, Germany; MRC Centre for Neuromuscular Diseases (A.C., N.D., H.H.), Department of Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, UCL Queen Square Institute of Neurology, London, UK; Department of Brain and Behaviour Sciences (A.C.), University Pavia, Italy; Department of Neurology (J.F., T.K.), University Hospital Bonn; German Center for Neurodegenerative Diseases (DZNE) (J.F., H.J., T.K.), Bonn; Department of Neurology (H.J.), University Hospital of Heidelberg; Department of Psychiatry, Psychotherapy and Psychosomatics (A.M.H., D.R.), University of Halle, Germany; Département de Neurologie (S.M., M.A.), Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg; Department of Neurology (A.E.-L.), APHP, CHU de Bicêtre; French National Reference Center for Rare Neuropathies (NNERF) (A.E.-L.); Inserm U1195 and Paris-Sud University (A.E.-L.), Le Kremlin Bicêtre, France; Medical Faculty (S.E.), Department of Neurology, Uludag University, Bursa, Turkey; University of Zurich (V.C.S., A.A.T.); Department of Neurology (V.C.S., A.A.T.), University Hospital Zurich, Switzerland; Institute of Medical Genetics and Applied Genomics (M. Sturm, T.B.H.) and Center for Rare Diseases (T.B.H.), University of Tübingen, Germany; Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC) (N.V.-D., H.P.); INSERM (N.V.-D., H.P.), U1258; CNRS (N.V.-D., H.P.), UMR7104, Illkirch; Université de Strasbourg (H.P.), France; Department of Neurology (B.P.v.d.W.), Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Centre, Nijmegen, the Netherlands; Department of Neurology (M.P.), Karolinska University Hospital; Department of Clinical Neuroscience (M.P.), Karolinska Institute, Stockholm, Sweden; Department of Neurology (D.T.), Essen University Hospital, University of Duisburg-Essen, Essen; Department of Medical Statistics (R.-D.H.), RWTH Aachen University, Germany; Department of Neurology (J.G.), Hospital Universitario Miguel Servet. Zaragoza, Spain; Department of Neurology (M. Strupp), University Hospital, and German Center for Vertigo and Balance Disorders (M.Strupp), Ludwig Maximilians University, Munich, Germany; Neurology Service (G.M.), Hospital Unversitario Central de Asturias (HUCA), SESPA, Oviedo, Spain; Department of Neurosciences and Reproductive and Odontostomatological Sciences (A.F.), Federico II University Naples, Italy; Institute of Genetics and Molecular and Cellular Biology (M.A.), INSERM-U964/CNRS-UMR7104, University of Strasbourg, Illkirch; Strasbourg Federation of Translational Medicine (M.A.), University of Strasbourg, Strasbourg, France; Service of Neurology (J.I.), University Hospital "Marqués de Valdecilla (IDIVAL)," University of Cantabria, "Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED)," Santander, Spain; and Suna and Inan Kıraç Foundation (A.N.B.), Neurodegeneration Research Laboratory, KUTTAM, Koç University School of Medicine, Istanbul, Turkey.

Objective: To delineate the full phenotypic spectrum, discriminative features, piloting longitudinal progression data, and sample size calculations of replication factor complex subunit 1 (RFC1) repeat expansions, recently identified as causing cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS).

Methods: Multimodal repeat screening (PCR, Southern blot, whole-exome/genome sequencing-based approaches) combined with cross-sectional and longitudinal deep phenotyping in (1) cross-European cohort A (70 families) with ≥2 features of CANVAS or ataxia with chronic cough (ACC) and (2) Turkish cohort B (105 families) with unselected late-onset ataxia.

Results: Prevalence of RFC1 disease was 67% in cohort A, 14% in unselected cohort B, 68% in clinical CANVAS, and 100% in ACC. RFC1 disease was also identified in Western and Eastern Asian individuals and even by whole-exome sequencing. Visual compensation, sensory symptoms, and cough were strong positive discriminative predictors (>90%) against RFC1-negative patients. The phenotype across 70 RFC1-positive patients was mostly multisystemic (69%), including dysautonomia (62%) and bradykinesia (28%) (overlap with cerebellar-type multiple system atrophy [MSA-C]), postural instability (49%), slow vertical saccades (17%), and chorea or dystonia (11%). Ataxia progression was ≈1.3 Scale for the Assessment and Rating of Ataxia points per year (32 cross-sectional, 17 longitudinal assessments, follow-up ≤9 years [mean 3.1 years]) but also included early falls, variable nonlinear phases of MSA-C-like progression (SARA points 2.5-5.5 per year), and premature death. Treatment trials require 330 (1-year trial) and 132 (2-year trial) patients in total to detect 50% reduced progression.

Conclusions: RFC1 disease is frequent and occurs across continents, with CANVAS and ACC as highly diagnostic phenotypes yet as variable, overlapping clusters along a continuous multisystemic disease spectrum, including MSA-C-overlap. Our natural history data help to inform future RFC1 treatment trials.

Classification Of Evidence: This study provides Class II evidence that RFC1 repeat expansions are associated with CANVAS and ACC.
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March 2021

Impact of Subthalamic Deep Brain Stimulation on Impulse Control Disorders in Parkinson's Disease: A Prospective Study.

Mov Disord 2021 Mar 6;36(3):750-757. Epub 2020 Oct 6.

Department of Neurology, NS-PARK/F-CRIN, Strasbourg University Hospital, Fédération de Médecine Translationnelle de Médecine de Strasbourg, Strasbourg, France.

Background: Impact of subthalamic deep brain stimulation (DBS) on impulse control disorders (ICD) in Parkinson's disease (PD) remains controversial.

Objectives: The objectives of this study were to analyze the natural history of ICD between baseline and 1 year after subthalamic DBS in patients with PD and to identify predictive factors, taking into account the positions of the active contact and stimulation parameters.

Methods: We analyzed postoperative modifications of ICD based on the multicentric, prospective Predictive Factors and Subthalamic Stimulation in Parkinson's Disease cohort. ICD status and Ardouin Scale of Behaviour in PD were assessed at baseline and 1 year following subthalamic DBS. Location of active contacts within the 3 subthalamic nucleus functional territories was investigated.

Results: A total of 217 were patients included. Of the patients, 10.6% had ICD at baseline of which 95.6% improved at 1 year following subthalamic DBS; 3.6% of the patients experienced de novo ICD at 1 year following subthalamic DBS. Dopamine agonist dose reduction (from 309.8 to 109.3 mg) was the main driver of ICD regression (P = 0.05). Higher preoperative dyskinesias were associated with poorer ICD evolution (P = 0.04). Whereas baseline apathy was a risk factor of de novo ICD (P = 0.02), ICD improvement correlated with postoperative apathy (P = 0.004). Stimulation power and position of active contacts-mainly located within the sensorimotor part of the subthalamic nucleus-did not influence ICD.

Conclusions: This 1-year, postoperative follow-up study showed ICD regression and dopaminergic drug reduction with optimal position of the active contacts within the subthalamic nucleus. Whereas patients with PD with preoperative ICD were prone to postoperative apathy, we also showed that those with preoperative apathy had a higher risk to experience postoperative de novo ICD, further highlighting the meaningful influence of postoperative management of dopaminergic medication on outcome and the continuum between apathy and ICD. © 2020 International Parkinson and Movement Disorder Society.
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March 2021

Toe dystonia in Parkinson's disease: Impact of subthalamic nucleus deep brain stimulation.

J Neurol Sci 2018 09 12;392:65-68. Epub 2018 Jul 12.

Institut des Sciences Cognitives Marc Jeannerod, UMR 5229, CNRS, Bron, France; Service de Neurologie C, Centre Expert Parkinson, Hôpital Neurologique Pierre, Wertheimer, Hospices Civils de Lyon, Lyon, France; Faculté de médecine Lyon Sud Charles Mérieux, Université Lyon 1, Univ Lyon, Lyon, France.

Background: Off state toe dystonia (TD) is a symptom frequently encountered in Parkinson's disease (PD), but little is known about its evolution after subthalamic nucleus deep brain stimulation (STN-DBS).

Objective: To analyze the prevalence and the evolution of TD in PD patients candidate to STN-DBS.

Methods: Individual data of consecutive 130 PD patients who underwent STN-DBS between 2010 and 2015 were collected.

Results: Data were successfully collected in 95 patients. TD affect 45.3% of the patients in our cohort. TD was present in 32.7% of patients before surgery and was alleviated by STN-DBS in 48% of the cases. Motor improvement provided by STN-DBS, levodopa-equivalent treatment diminution after surgery, disease duration or age at the time of surgery were not predictive of TD evolution. A younger age at PD diagnosis was significantly associated with TD resolution.

Conclusion: STN-DBS is partially efficient for TD but its evolution seems independent of significant predictive factors.
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September 2018

Assessment of a Targeted Gene Panel for Identification of Genes Associated With Movement Disorders.

JAMA Neurol 2018 10;75(10):1234-1245

Département de Neurologie, Hôpital de Hautepierre, Hôpitaux Universitaires de Strasbourg, Strasbourg, France.

Importance: Movement disorders are characterized by a marked genotypic and phenotypic heterogeneity, complicating diagnostic work in clinical practice and molecular diagnosis.

Objective: To develop and evaluate a targeted sequencing approach using a customized panel of genes involved in movement disorders.

Design, Setting And Participants: We selected 127 genes associated with movement disorders to create a customized enrichment in solution capture array. Targeted high-coverage sequencing was applied to DNA samples taken from 378 eligible patients at 1 Luxembourgian, 1 Algerian, and 25 French tertiary movement disorder centers between September 2014 and July 2016. Patients were suspected of having inherited movement disorders because of early onset, family history, and/or complex phenotypes. They were divided in 5 main movement disorder groups: parkinsonism, dystonia, chorea, paroxysmal movement disorder, and myoclonus. To compare approaches, 23 additional patients suspected of having inherited cerebellar ataxia were included, on whom whole-exome sequencing (WES) was done. Data analysis occurred from November 2015 to October 2016.

Main Outcomes And Measures: Percentages of individuals with positive diagnosis, variants of unknown significance, and negative cases; mutational frequencies and clinical phenotyping of genes associated with movement disorders.

Results: Of the 378 patients (of whom 208 were male [55.0%]), and with a median (range) age at disease onset of 31 (0-84) years, probable pathogenic variants were identified in 83 cases (22.0%): 46 patients with parkinsonism (55% of 83 patients), 21 patients (25.3%) with dystonia, 7 patients (8.4%) with chorea, 7 patients (8.4%) with paroxysmal movement disorders, and 2 patients (2.4%) with myoclonus as the predominant phenotype. Some genes were mutated in several cases in the cohort. Patients with pathogenic variants were significantly younger (median age, 27 years; interquartile range [IQR], 5-36 years]) than the patients without diagnosis (median age, 35 years; IQR, 15-46 years; P = .04). Diagnostic yield was significantly lower in patients with dystonia (21 of 135; 15.6%; P = .03) than in the overall cohort. Unexpected genotype-phenotype correlations in patients with pathogenic variants deviating from the classic phenotype were highlighted, and 49 novel probable pathogenic variants were identified. The WES analysis of the cohort of 23 patients with cerebellar ataxia led to an overall diagnostic yield of 26%, similar to panel analysis but at a cost 6 to 7 times greater.

Conclusions And Relevance: High-coverage sequencing panel for the delineation of genes associated with movement disorders was efficient and provided a cost-effective diagnostic alternative to whole-exome and whole-genome sequencing.
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October 2018

SCA13 causes dominantly inherited non-progressive myoclonus ataxia.

Parkinsonism Relat Disord 2017 05 11;38:80-84. Epub 2017 Feb 11.

Département de Neurologie, Hôpital de Hautepierre, CHU de Strasbourg, Strasbourg, France; Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, Illkirch, France; Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France. Electronic address:

Introduction: Spinocerebellar ataxia 13 (SCA13) is a rare autosomal dominant cerebellar ataxia. To our knowledge, its association to movement disorders has never been described. We aimed at reporting 8 new SCA13 cases with a focus on movement disorders especially myoclonus.

Methods: We performed a detailed neurological examination and neurophysiological recording in 8 patients consecutively diagnosed with SCA13 between December 2013 and October 2015 and followed up in two French tertiary centers.

Results: We identified mild subcortical myoclonus in all patients, with a homogenous clinical and electrophysiological pattern. Myoclonus ataxia was very slowly progressive, like the other symptoms of the disease, whatever the age of onset. Patients with R423H mutation had an earlier age of onset than patients with R420H mutation.

Conclusions: Myoclonus appears to be frequent in SCA13. SCA13 should be considered facing non-progressive autosomal dominant myoclonus ataxia, and polymyographic recording should be included in the diagnosis work.
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May 2017