title: Early diagnosis of Alzheimer's disease and Parkinson's disease associated with dementia using cerebral perfusion SPECT.
abstract: BACKGROUND
  Since patterns of cognitive dysfunction in mild Parkinson's disease associated with dementia (PDD) are similar to those in mild Alzheimer's disease (AD), it is difficult to accurately differentiate between these two types of dementia in their early phases using neuropsychological tests. The purpose of the current study was to investigate differences in cerebral perfusion patterns of patients with AD and PDD at the earliest stages using single photon emission computed tomography (SPECT).
  
  
  METHODS
  We consecutively recruited 31 patients with mild PDD, 32 patients with mild probable AD and 33 age-matched healthy subjects. All subjects underwent (99m)Tc-hexamethylpropyleneamine oxime perfusion SPECT and completed general neuropsychological tests.
  
  
  RESULTS
  We found that both mild PDD and AD patients showed distinct hypoperfusion in frontal, parietal and temporal regions, compared with healthy subjects. More importantly, hypoperfusion in occipital and cerebellar regions was observed only in mild PDD.
  
  
  CONCLUSIONS
  The observation of a significant decrease in cerebral perfusion in occipital and cerebellar regions in patients with mild PDD is likely useful to differentiate between PDD and AD at the earliest stages.
authors.affiliation: Department of Neurology, College of Medicine, The Catholic University of Korea, Seoul, South Korea.
authors.forename: In-Uk
authors.initials: IU
authors.lastname: Song
authors.forename: Yong-An
authors.initials: YA
authors.lastname: Chung
authors.forename: Sung-Woo
authors.initials: SW
authors.lastname: Chung
authors.forename: Jaeseung
authors.initials: J
authors.lastname: Jeong
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging*; D001921:Brain / Q000000981:diagnostic imaging*; D016022:Case-Control Studies; D002560:Cerebrovascular Circulation; D003704:Dementia / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000209:etiology; D003937:Diagnosis, Differential; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000175:diagnosis / Q000000981:diagnostic imaging*; D055420:Perfusion Imaging; D015899:Tomography, Emission-Computed, Single-Photon