title: Subclinical nigrostriatal dopaminergic denervation in the cerebellar subtype of multiple system atrophy (MSA-C).
abstract: Nigrostriatal involvement is considered an additional feature in the new consensus criteria for the diagnosis of the cerebellar variant of multiple system atrophy (MSA-C). However, so far, only a few studies, which include a relative small number of patients, give support to this criterion. Our objective was to assess nigrostriatal dopaminergic innervation in patients with MSA-C without parkinsonism by use of dopamine transporter single photon emission computed tomography (DAT SPECT). Thirteen patients that fulfilled criteria for possible or probable MSA-C and presented no parkinsonian signs, and 12 age-matched healthy controls underwent ((123)I-2-β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane ([(123)I]FP-CIT) SPECT. Patients were also evaluated through the Unified Multiple System Atrophy Rating Scale (UMSARS) and brain magnetic resonance imaging (MRI). The mean duration of the cerebellar syndrome was 3.8 ± 1.7 years. DAT SPECT showed a significant decrease of striatal [(123)I]FP-CIT uptake ratios in patients (p < 0.001). Radiotracer uptake reduction was 21% in the entire striatum, 19% in putamen, and 24% in caudate nuclei. Striatal binding ratios were within the normal range in 3 patients. We did not find correlation between striatal uptake and disease duration, age of patients, UMSARS-II score, and pontine diameter. [(123)I]FP-CIT SPECT shows that most but not all MSA-C patients without parkinsonism have subclinical nigrostriatal dopaminergic denervation which is not related to disease duration, cerebellar dysfunction, or pontine atrophy.
authors.affiliation: Parkinson's Disease and Movement Disorders Unit, Neurology Service, Institut Clínic de Neurociències (ICN), Hospital Clínic i Universitari, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación en Red de Enfermedades Neurodegenerativas (CIBERNED), Villarroel 170, 08036, Barcelona, Catalunya, Spain. jemunoz@clinic.ub.es
authors.forename: Esteban
authors.initials: E
authors.lastname: Muñoz
authors.forename: Alex
authors.initials: A
authors.lastname: Iranzo
authors.forename: Sebastian
authors.initials: S
authors.lastname: Rauek
authors.forename: Francisco
authors.initials: F
authors.lastname: Lomeña
authors.forename: Judith
authors.initials: J
authors.lastname: Gallego
authors.forename: Doménec
authors.initials: D
authors.lastname: Ros
authors.forename: Joan
authors.initials: J
authors.lastname: Santamaría
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tolosa
mesh_terms: D000328:Adult; D000368:Aged; D003342:Corpus Striatum / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D019275:Radiopharmaceuticals; D013378:Substantia Nigra / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D015899:Tomography, Emission-Computed, Single-Photon; D014326:Tropanes
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane