title: Diffusion tensor imaging in dementia with Lewy bodies and Alzheimer's disease.
abstract: Dementia with Lewy bodies (DLB) is a common form of dementia, with fewer memory deficits, and more visuo-perceptual problems than Alzheimer's disease (AD). We hypothesized that there would be disease specific alterations revealed by diffusion tensor imaging with AD showing temporal lobe and DLB more parietal changes. We recruited 15 people with AD, 16 with DLB, and 15 healthy control subjects of similar age. They were scanned on a 1.5 T MRI system with diffusion tensor FLAIR imaging. Apparent diffusion coefficient (ADC) and fractional anisotropy (FA) maps were calculated, and data were analysed using pre-defined regions of interest (ROI) and also with SPM. We found a significant decrease in the FA map in a ROI in the parietal lobe (precuneus) of the DLB group. Using SPM we found increased ADC in the left temporal lobe of AD subjects compared to controls. There were no other significant differences between groups. We conclude that there are subtle changes visible with diffusion imaging in DLB and AD which may reflect disrupted connectivity and underlie observed perfusion changes in these disorders.
authors.affiliation: Institute for Ageing and Health, Newcastle University, Wolfson Research Centre, Westgate Road, Newcastle upon Tyne, UK. m.j.firbank@ncl.ac.uk
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Firbank
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Blamire
authors.forename: Mani S
authors.initials: MS
authors.lastname: Krishnan
authors.forename: Andrew
authors.initials: A
authors.lastname: Teodorczuk
authors.forename: Philip
authors.initials: P
authors.lastname: English
authors.forename: Anil
authors.initials: A
authors.lastname: Gholkar
authors.forename: Roger M
authors.initials: RM
authors.lastname: Harrison
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000473:pathology*; D016880:Anisotropy; D001921:Brain / Q000473:pathology; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods / Q000706:statistics & numerical data*; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020961:Lewy Body Disease / Q000175:diagnosis / Q000473:pathology*; D008297:Male; D009434:Neural Pathways / Q000473:pathology; D010296:Parietal Lobe / Q000473:pathology*; D013702:Temporal Lobe / Q000473:pathology*