title: Brain regions associated with cognitive impairment in patients with Parkinson disease: quantitative analysis of cerebral blood flow using 123I iodoamphetamine SPECT.
abstract: OBJECTIVE
  Cognitive impairment is a representative neuropsychiatric presentation that accompanies Parkinson disease (PD). The purpose of this study was to localize the cerebral regions associated with cognitive impairment in patients with PD using quantitative SPECT.
  
  
  METHODS
  Thirty-two patients with PD (mean [SD] age, 75 [8] years; 25 women; Hoehn-Yahr scores from 2 to 5) underwent quantitative brain SPECT using 123I iodoamphetamine. Parametric images of regional cerebral blood flow (rCBF) were spatially normalized to the standard brain atlas. First, voxel-by-voxel comparison between patients with PD with versus without cognitive impairment was performed to visualize overall trend of regional differences. Next, the individual quantitative rCBF values were extracted in representative cortical regions using a standard region-of-interest template to compare the quantitative rCBF values.
  
  
  RESULTS
  Patients with cognitive impairment showed trends of lower rCBF in the left frontal and temporal cortices as well as in the bilateral medial frontal and anterior cingulate cortices in the voxel-by-voxel analyses. Region-of-interest-based analysis demonstrated significantly lower rCBF in the bilateral anterior cingulate cortices (right, 25.8 [5.5] vs 28.9 [5.7] mL per 100 g/min, P < 0.05; left, 25.8 [5.8] vs 29.1 [5.7] mL per 100 g/min, P < 0.05) associated with cognitive impairment.
  
  
  CONCLUSIONS
  Patients with cognitive impairment showed lower rCBF in the left frontal and temporal cortices as well as in the bilateral medial frontal and anterior cingulate cortices. The results suggested dysexecutive function as an underlining mechanism of cognitive impairment in patients with PD.
authors.affiliation: Department of Molecular Imaging, Hokkaido University Graduate School of Medicine, Sapporo, Japan. nhattori@med.hokudai.ac.jp
authors.forename: Naoya
authors.initials: N
authors.lastname: Hattori
authors.forename: Ichiro
authors.initials: I
authors.lastname: Yabe
authors.forename: Kenji
authors.initials: K
authors.lastname: Hirata
authors.forename: Tohru
authors.initials: T
authors.lastname: Shiga
authors.forename: Ken
authors.initials: K
authors.lastname: Sakushima
authors.forename: Sachiko
authors.initials: S
authors.lastname: Tsuji-Akimoto
authors.forename: Hidenao
authors.initials: H
authors.lastname: Sasaki
authors.forename: Nagara
authors.initials: N
authors.lastname: Tamaki
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000662:Amphetamines; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D012039:Regional Blood Flow; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D000662:Amphetamines; C041336:4-iodoamphetamine