title: Neural correlates of attention-executive dysfunction in lewy body dementia and Alzheimer's disease.
abstract: Attentional and executive dysfunction contribute to cognitive impairment in both Lewy body dementia and Alzheimer's disease. Using functional MRI, we examined the neural correlates of three components of attention (alerting, orienting, and executive/conflict function) in 23 patients with Alzheimer's disease, 32 patients with Lewy body dementia (19 with dementia with Lewy bodies and 13 with Parkinson's disease with dementia), and 23 healthy controls using a modified Attention Network Test. Although the functional MRI demonstrated a similar fronto-parieto-occipital network activation in all groups, Alzheimer's disease and Lewy body dementia patients had greater activation of this network for incongruent and more difficult trials, which were also accompanied by slower reaction times. There was no recruitment of additional brain regions or, conversely, regional deficits in brain activation. The default mode network, however, displayed diverging activity patterns in the dementia groups. The Alzheimer's disease group had limited task related deactivations of the default mode network, whereas patients with Lewy body dementia showed heightened deactivation to all trials, which might be an attempt to allocate neural resources to impaired attentional networks. We posit that, despite a common endpoint of attention-executive disturbances in both dementias, the pathophysiological basis of these is very different between these diseases.
authors.affiliation: Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Firbank
authors.affiliation: Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom.|Department of Neurology and Neurophysiology, Medical School Hannover, Carl-Neuberg-Straße 1, Hannover, 30625, Germany.
authors.forename: Xenia
authors.initials: X
authors.lastname: Kobeleva
authors.affiliation: School of Medical Science, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, United Kingdom.
authors.forename: George
authors.initials: G
authors.lastname: Cherry
authors.affiliation: Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom.
authors.forename: Alison
authors.initials: A
authors.lastname: Killen
authors.affiliation: Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom.
authors.forename: Peter
authors.initials: P
authors.lastname: Gallagher
authors.affiliation: Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom.
authors.forename: David J
authors.initials: DJ
authors.lastname: Burn
authors.affiliation: Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom.
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Thomas
authors.affiliation: Department of Psychiatry, University of Cambridge School of Clinical Medicine, Cambridge, CB2 0SP, United Kingdom.
authors.forename: John T
authors.initials: JT
authors.lastname: O'Brien
authors.affiliation: Institute of Neuroscience, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, United Kingdom.
authors.forename: John-Paul
authors.initials: JP
authors.lastname: Taylor
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000503:physiopathology*; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D003463:Cues; D056344:Executive Function / Q000502:physiology*; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000188:drug therapy / Q000503:physiopathology* / Q000523:psychology; D008279:Magnetic Resonance Imaging; D008297:Male; D009483:Neuropsychological Tests; D018697:Nootropic Agents / Q000627:therapeutic use; D010775:Photic Stimulation; D011930:Reaction Time; D014796:Visual Perception / Q000502:physiology
chemical_list: D002800:Cholinesterase Inhibitors; D018697:Nootropic Agents
keywords: Alzheimer's disease; Lewy body dementia; attention; attention network test; executive; functional MRI