title: Comparison of Cerebral Glucose Metabolism between Possible and Probable Multiple System Atrophy.
abstract: BACKGROUND
  To investigate the relationship between presenting clinical manifestations and imaging features of multisystem neuronal dysfunction in MSA patients, using (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET).
  
  
  METHODS
  We studied 50 consecutive MSA patients with characteristic brain MRI findings of MSA, including 34 patients with early MSA-parkinsonian (MSA-P) and 16 with early MSA-cerebellar (MSA-C). The cerebral glucose metabolism of all MSA patients was evaluated in comparison with 25 age-matched controls. (18)F-FDG PET results were assessed by the Statistic Parametric Mapping (SPM) analysis and the regions of interest (ROI) method.
  
  
  RESULTS
  The mean time from disease onset to (18)F-FDG PET was 25.9±13.0 months in 34 MSA-P patients and 20.1±11.1 months in 16 MSA-C patients. Glucose metabolism of the putamen showed a greater decrease in possible MSA-P than in probable MSA-P (p=0.031). Although the Unified Multiple System Atrophy Rating Scale (UMSARS) score did not differ between possible MSA-P and probable MSA-P, the subscores of rigidity (p=0.04) and bradykinesia (p= 0.008) were significantly higher in possible MSA-P than in probable MSA-P. Possible MSA-C showed a greater decrease in glucose metabolism of the cerebellum than probable MSA-C (p=0.016).
  
  
  CONCLUSIONS
  Our results may suggest that the early neuropathological pattern of possible MSA with a predilection for the striatonigral or olivopontocerebellar system differs from that of probable MSA, which has prominent involvement of the autonomic nervous system in addition to the striatonigral or olivopontocerebellar system.
authors.affiliation: Center for Parkinsonism and Other Movement Disorders, Departments of Neurology, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Kyum-Yil
authors.initials: KY
authors.lastname: Kwon
authors.affiliation: Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Jae Seung
authors.initials: JS
authors.lastname: Kim
authors.affiliation: Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Ki Chun
authors.initials: KC
authors.lastname: Im
authors.affiliation: Center for Parkinsonism and Other Movement Disorders, Departments of Neurology, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Myoung Chong
authors.initials: MC
authors.lastname: Lee
authors.affiliation: Center for Parkinsonism and Other Movement Disorders, Departments of Neurology, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Sun Ju
authors.initials: SJ
authors.lastname: Chung
keywords: 18F-fluorodeoxyglucose positron emission tomography; Autonomic dysfunction; Cerebellar dysfunction; Multiple system atrophy; Parkinsonism