title: PET and MRI detection of early and progressive neurodegeneration in spinocerebellar ataxia type 36.
abstract: The spinocerebellar ataxias (SCAs) form a clinically, genetically, and pathological heterogeneous group of autosomal-dominant degenerative diseases. In particular, SCA36 is characterized by a late-onset, slowly progressive cerebellar syndrome typically associated with sensorineural hearing loss. This study was aimed at analyzing the neurodegenerative process underlying SCA36 through fluorodeoxyglucose positron emission tomography (FDG-PET) and MRI scans.
  
  
  
  Twenty SCA36 patients underwent a study consisting of FDG-PET and MRI scans. Clinical motor evaluation was performed through the Scale for the Assessment and Rating of Ataxia (SARA). FDG-PET was carried out using a voxel-by-voxel and region-of-interest analysis. MRI evaluation was based on visual inspection and volumetric analysis.
  
  
  
  SARA ranged from 0 to 24.5 (4 patients asymptomatic, 3 with unspecific symptoms, and 13 with cerebellar signs). FDG-PET revealed hypometabolism in the asymptomatic stage in the vermis and right cerebellar hemisphere. In the ataxic stage, hypometabolism spread to both cerebellar hemispheres and the brain stem. MRI was normal in asymptomatic and preataxic individuals and showed superior cerebellar vermis atrophy early in the ataxic stage, diffuse cerebellar atrophy some years into the disease course, and a pattern of olivopontocerebellar atrophy in the oldest patients. There was no significant cerebellar atrophy in patients younger than 50 years.
  
  
  
  We present the first FDG-PET study of SCA36 and one of the largest neuroimaging study of SCAs. Our results revealed neuronal dysfunctions in the vermis and right cerebellar hemisphere as soon as a decade before the onset of motor symptoms. In the ataxic stage, dysfunctions spread to both hemispheres and the brain stem. © 2016 International Parkinson and Movement Disorder Society.
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging Group, University Hospital of Santiago de Compostela (CHUS), IDIS Health Research Institute, Santiago de Compostela, Spain.|Department of Psychiatry, Radiology and Public Health, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Aguiar
authors.affiliation: Department of Psychiatry, Radiology and Public Health, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain.|Department of Neurology, University Hospital of Santiago de Compostela (CHUS), Santiago de Compostela, Spain.|Neurogenetics research group, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain.
authors.forename: Julio
authors.initials: J
authors.lastname: Pardo
authors.affiliation: Department of Psychiatry, Radiology and Public Health, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain.|Department of Neurology, University Hospital of Santiago de Compostela (CHUS), Santiago de Compostela, Spain.|Neurogenetics research group, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Arias
authors.affiliation: Neurogenetics research group, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain.|Genomic Medicine Group (U711), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Madrid, Spain.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Quintáns
authors.affiliation: Neurogenetics research group, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain.|Genomic Medicine Group (U711), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Madrid, Spain.
authors.forename: Montse
authors.initials: M
authors.lastname: Fernández-Prieto
authors.affiliation: Neurogenetics research group, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain.|Department of Clinical Psychology and Psychobiology, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain.
authors.forename: Rocío
authors.initials: R
authors.lastname: Martínez-Regueiro
authors.affiliation: Department of Psychiatry, Radiology and Public Health, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain.|Department of Radiology, University Hospital of Santiago de Compostela (CHUS), Santiago de Compostela, Spain.
authors.forename: José-Manuel
authors.initials: JM
authors.lastname: Pumar
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging Group, University Hospital of Santiago de Compostela (CHUS), IDIS Health Research Institute, Santiago de Compostela, Spain.
authors.forename: Jesús
authors.initials: J
authors.lastname: Silva-Rodríguez
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging Group, University Hospital of Santiago de Compostela (CHUS), IDIS Health Research Institute, Santiago de Compostela, Spain.|Department of Psychiatry, Radiology and Public Health, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain.
authors.forename: Álvaro
authors.initials: Á
authors.lastname: Ruibal
authors.affiliation: Neurogenetics research group, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain.|Genomic Medicine Group (U711), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Madrid, Spain.
authors.forename: María-Jesús
authors.initials: MJ
authors.lastname: Sobrido
authors.affiliation: Department of Nuclear Medicine and Molecular Imaging Group, University Hospital of Santiago de Compostela (CHUS), IDIS Health Research Institute, Santiago de Compostela, Spain.|Department of Psychiatry, Radiology and Public Health, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain.
authors.forename: Julia
authors.initials: J
authors.lastname: Cortés
mesh_terms: D000328:Adult; D000368:Aged; D001933:Brain Stem / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D065814:Cerebellar Vermis / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology; D002531:Cerebellum / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009687:Nuclear Proteins; D049268:Positron-Emission Tomography / Q000379:methods*; D012720:Severity of Illness Index; D020754:Spinocerebellar Ataxias / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology
chemical_list: C486600:NOP56 protein, human; D009687:Nuclear Proteins
keywords: MRI; PET; ataxia; neurodegeneration; preataxic stage