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 (123I-2-β-carbomethoxy-3β-(4-iodophenyl)-N-(3-fluoropropyl) nortropane ([123I]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 [123I]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. [123I]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.
Multiple system atrophyMSA-CDopamine transporterSPECTNigrostriatal dopaminergic denervation
1.Parkinson’s Disease and Movement Disorders Unit, Neurology Service, Institut Clínic de Neurociències (ICN), Hospital Clínic i UniversitariInstitut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Centro de Investigación en Red de Enfermedades Neurodegenerativas (CIBERNED)BarcelonaSpain
2.Sleep Disorders Unit, Neurology Service, ICN, Hospital Clínic i UniversitariIDIBAPS, CIBERNEDBarcelonaSpain
3.Nuclear Medicine Service, Centre de Diagnòstic per la Imatge (CDI), Hospital Clínic i UniversitariInstitut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)BarcelonaSpain
4.Biophysics Unit, Department of Physiological Sciences IBiomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBERBBN), University of BarcelonaBarcelonaSpain