Pablo Aguiar1,2, Julio Pardo2,3,4, Manuel Arias2,3,4, Beatriz Quintáns4,5, Montse Fernández-Prieto4,5, Rocío Martínez-Regueiro4,6, José-Manuel Pumar2,7, Jesús Silva-Rodríguez1, Álvaro Ruibal1,2, María-Jesús Sobrido4,5, Julia Cortés1,2. 1. Department of Nuclear Medicine and Molecular Imaging Group, University Hospital of Santiago de Compostela (CHUS), IDIS Health Research Institute, Santiago de Compostela, Spain. 2. Department of Psychiatry, Radiology and Public Health, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain. 3. Department of Neurology, University Hospital of Santiago de Compostela (CHUS), Santiago de Compostela, Spain. 4. Neurogenetics research group, Instituto de Investigaciones Sanitarias de Santiago (IDIS), Santiago de Compostela, Spain. 5. Genomic Medicine Group (U711), Centre for Biomedical Network Research on Rare Diseases (CIBERER), Institute of Health Carlos III, Madrid, Spain. 6. Department of Clinical Psychology and Psychobiology, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain. 7. Department of Radiology, University Hospital of Santiago de Compostela (CHUS), Santiago de Compostela, Spain.
Abstract
BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.
BACKGROUND: 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. METHODS: Twenty SCA36patients 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. RESULTS: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. CONCLUSIONS: 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.
Authors: Alex Tiburtino Meira; Walter Oleschko Arruda; Sergio Eiji Ono; Arnolfo de Carvalho Neto; Salmo Raskin; Carlos Henrique F Camargo; Hélio Afonso G Teive Journal: Tremor Other Hyperkinet Mov (N Y) Date: 2019-09-26