title: Longitudinal diffusion tensor imaging in dementia with Lewy bodies and Alzheimer's disease.
abstract: OBJECTIVE
  Changes in the white matter of dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) have been reported using diffusion weighted MRI, though few longitudinal studies have been done.
  
  
  METHODS
  We performed diffusion weighted MRI twice, a year apart on 23 AD, 14 DLB, and 32 healthy control subjects. Mean diffusivity (MD) and fractional anisotropy (FA) were calculated.
  
  
  RESULTS
  In AD, there were widespread regions where the longitudinal MD increase was greater than in controls, and small areas in the parietal and temporal lobes where it was greater in AD than DLB. In AD, decrease in brain volume correlated with increased MD. There were no significant differences in progression between DLB and controls.
  
  
  CONCLUSIONS
  In AD the white matter continues to degenerate during the disease process, whereas in DLB, changes in the white matter structure are a relatively early feature. Different mechanisms are likely to underpin changes in diffusivity.
authors.affiliation: Institute for Neuroscience and Newcastle University Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK. Electronic address: michael.firbank@ncl.ac.uk.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Firbank
authors.affiliation: Institute for Neuroscience and Newcastle University Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK; The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, Australia; The Department of Aged Care, The Royal Melbourne Hospital, Parkville, Australia.
authors.forename: Rosie
authors.initials: R
authors.lastname: Watson
authors.affiliation: Department of Psychiatry, University of Cambridge School of Clinical Medicine, Box 189, Level E4, Cambridge Biomedical Campus, Cambridge, UK.
authors.forename: Elijah
authors.initials: E
authors.lastname: Mak
authors.affiliation: Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK; Computer Science Department, Faculty of Science, Lagos State University, Lagos, Nigeria.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Aribisala
authors.affiliation: Institute for Neuroscience and Newcastle University Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Barber
authors.affiliation: Institute for Neuroscience and Newcastle University Institute for Ageing, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Sean J
authors.initials: SJ
authors.lastname: Colloby
authors.affiliation: Aberdeen Biomedical Imaging Centre, University of Aberdeen, UK.
authors.forename: Jiabao
authors.initials: J
authors.lastname: He
authors.affiliation: Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne, UK.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Blamire
authors.affiliation: Department of Psychiatry, University of Cambridge School of Clinical Medicine, Box 189, Level E4, Cambridge Biomedical Campus, Cambridge, UK.
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D000704:Analysis of Variance; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D020961:Lewy Body Disease / Q000000981:diagnostic imaging*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D013223:Statistics as Topic
keywords: Alzheimer's disease; DWI; Dementia with Lewy bodies; MRI