title: Amyloid and glucose imaging in dementia with Lewy bodies and multiple systems atrophy.
abstract: BACKGROUND
  Multiple Systems Atrophy (MSA) and Dementia with Lewy bodies (DLB) can present with both REM behavior disorder and severe autonomic dysfunction. In rare occasions, patients with MSA progress to cognitive impairment and even dementia. Positron emission topography (PET) imaging using both the amyloid ligand Pittsburgh Compound B (11C-PiB) and 18 flurodeoxyglucose (18F-FDG) was used to ascertain the presence of amyloid and pattern of glucose metabolic derangement in both disorders.
  
  
  METHODS
  Patients diagnosed with probable DLB or MSA, with clinical symptoms of either REM Behavior Disorder (RBD), Parkinsonism, or dysautonomia were prospectively identified. All underwent both 11C-PiB and 18F-FDG PET imaging. Statistical comparison between DLB, MSA, and normal controls was performed.
  
  
  RESULTS
  Six patients, 3 with DLB, 2 with Parkinson predominant MSA (MSA-P), and 1 with cerebellar predominant MSA (MSA-C) were identified. Increased level of PiB retention was noted in all patients diagnosed with DLB, but was absent in MSA. In those with DLB, glucose hypometabolism corresponded with regions of amyloid presence, and included prefrontal, parietotemporal, occipital and primary visual cortex regions. MSA patients were distinguished by cerebellar glucose hypometabolism.
  
  
  CONCLUSIONS
  These findings emphasize the distinguishing characteristics between the alpha-synuclein related disorders of DLB and MSA. The absence of amyloid in the cases of MSA is a possible distinguishing characteristic of the disorder.
authors.affiliation: Department of Neurology, University of Virginia, Charlottesville, VA, USA. dclaassen@virginia.edu
authors.forename: Daniel O
authors.initials: DO
authors.lastname: Claassen
authors.forename: Val J
authors.initials: VJ
authors.lastname: Lowe
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Peller
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Petersen
authors.forename: Keith A
authors.initials: KA
authors.lastname: Josephs
mesh_terms: D000368:Aged; D000682:Amyloid / Q000378:metabolism*; D000814:Aniline Compounds; D001931:Brain Mapping; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D020961:Lewy Body Disease / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D019578:Multiple System Atrophy / Q000000981:diagnostic imaging* / Q000473:pathology; D049268:Positron-Emission Tomography / Q000379:methods; D013844:Thiazoles; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: C475519:2-(4'-(methylamino)phenyl)-6-hydroxybenzothiazole; D000682:Amyloid; D000814:Aniline Compounds; D013844:Thiazoles; D019788:Fluorodeoxyglucose F18; D005947:Glucose