title: Lewy body compared with Alzheimer dementia is associated with decreased functional connectivity in resting state networks.
abstract: Resting state functional magnetic resonance imaging (fMRI) was used to measure whole brain functional connectivity within specific networks hypothesised to be more affected in dementia with Lewy bodies (DLB) (a disease characterised by prominent attentional deficits, spontaneous motor features of parkinsonism and depression) than in Alzheimer׳s disease (AD) and controls. This study involved 68 subjects (15 DLB, 13 AD and 40 controls) who were scanned using resting state BOLD (blood-oxygen-level-dependent) fMRI on a 3T MRI scanner. Functional connectivity was measured using a model-free independent component analysis approach that consisted of temporally concatenating the resting state fMRI data of all study subjects and investigating group differences using a back-reconstruction procedure. Resting state functional connectivity was affected in the default mode, salience, executive and basal ganglia networks in DLB subjects compared with AD and controls. Functional connectivity was lower in DLB compared with AD and controls in these networks, except for the basal ganglia network, where connectivity was greater in DLB. No resting state networks showed less connectivity in AD compared with DLB or controls. Our results suggest that functional connectivity of resting state networks can identify differences between DLB and AD subjects that may help to explain why DLB subjects have more frequent attentional deficits, parkinsonian symptoms, and depression than those with AD.
authors.affiliation: Institute for Ageing and Health and Newcastle Magnetic Resonance Centre, Campus for Ageing and Vitality, Newcastle University, Newcastle upon Tyne NE4 5PL, United Kingdom.
authors.forename: Eva R
authors.initials: ER
authors.lastname: Lowther
authors.affiliation: Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, United Kingdom; Department of Psychiatry, University of Cambridge, Cambridge, United Kingdom.
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
authors.affiliation: Institute for Ageing and Health, Newcastle University, Newcastle upon Tyne, United Kingdom.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Firbank
authors.affiliation: Institute for Cellular Medicine and Newcastle Magnetic Resonance Centre, Newcastle University, Newcastle upon Tyne, United Kingdom. Electronic address: andrew.blamire@ncl.ac.uk.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Blamire
mesh_terms: D000544:Alzheimer Disease / Q000473:pathology / Q000503:physiopathology*; D001921:Brain / Q000473:pathology / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020961:Lewy Body Disease / Q000473:pathology / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D010100:Oxygen / Q000097:blood
chemical_list: D010100:Oxygen
keywords: Basal ganglia; Default mode network; Functional MRI