title: Comparing cerebral perfusion in Alzheimer's disease and Parkinson's disease dementia: an ASL-MRI study.
abstract: Emerging evidence suggests that Alzheimer's disease (AD) and Parkinson's disease dementia (PDD) share neurodegenerative mechanisms. We sought to directly compare cerebral perfusion in these two conditions using arterial spin labeling magnetic resonance imaging (ASL-MRI). In total, 17 AD, 20 PDD, and 37 matched healthy controls completed ASL and structural MRI, and comprehensive neuropsychological testing. Alzheimer's disease and PDD perfusion was analyzed by whole-brain voxel-based analysis (to assess absolute blood flow), a priori specified region of interest analysis, and principal component analysis (to generate a network differentiating the two groups). Corrections were made for cerebral atrophy, age, sex, education, and MRI scanner software version. Analysis of absolute blood flow showed no significant differences between AD and PDD. Comparing each group with controls revealed an overlapping, posterior pattern of hypoperfusion, including posterior cingulate gyrus, precuneus, and occipital regions. The perfusion network that differentiated AD and PDD groups identified relative differences in medial temporal lobes (AD<PDD) and right frontal cortex (PDD<AD). In conclusion, the pattern of cerebral hypoperfusion is very similar in AD and PDD. This suggests closely linked mechanisms of neurodegeneration mediating the evolution of dementia in both conditions.
authors.affiliation: New Zealand Brain Research Institute, Christchurch, New Zealand.
authors.forename: Campbell J
authors.initials: CJ
authors.lastname: Le Heron
authors.affiliation: New Zealand Brain Research Institute, Christchurch, New Zealand.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Wright
authors.affiliation: 1] New Zealand Brain Research Institute, Christchurch, New Zealand [2] Department of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Tracy R
authors.initials: TR
authors.lastname: Melzer
authors.affiliation: New Zealand Brain Research Institute, Christchurch, New Zealand.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Myall
authors.affiliation: 1] New Zealand Brain Research Institute, Christchurch, New Zealand [2] Department of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Michael R
authors.initials: MR
authors.lastname: MacAskill
authors.affiliation: 1] New Zealand Brain Research Institute, Christchurch, New Zealand [2] Department of Medicine, University of Otago, Christchurch, New Zealand.
authors.forename: Leslie
authors.initials: L
authors.lastname: Livingston
authors.affiliation: 1] New Zealand Brain Research Institute, Christchurch, New Zealand [2] Christchurch Radiology Group, Christchurch, New Zealand.
authors.forename: Ross J
authors.initials: RJ
authors.lastname: Keenan
authors.affiliation: College of Medicine, University of Vermont, Burlington, Vermont, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Watts
authors.affiliation: 1] New Zealand Brain Research Institute, Christchurch, New Zealand [2] Department of Medicine, University of Otago, Christchurch, New Zealand [3] Department of Psychology, University of Canterbury, Christchurch, New Zealand.
authors.forename: John C
authors.initials: JC
authors.lastname: Dalrymple-Alford
authors.affiliation: 1] New Zealand Brain Research Institute, Christchurch, New Zealand [2] Department of Medicine, University of Otago, Christchurch, New Zealand [3] Department of Neurology, Christchurch Hospital, Christchurch, New Zealand.
authors.forename: Tim J
authors.initials: TJ
authors.lastname: Anderson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000503:physiopathology; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008032:Limbic System / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D018810:Magnetic Resonance Angiography; D008297:Male; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000503:physiopathology; D011859:Radiography