title: Thalamic Involvement in Fluctuating Cognition in Dementia with Lewy Bodies: Magnetic Resonance Evidences.
abstract: Dementia with Lewy bodies (DLB) is characterized by fluctuation in cognition and attention. Thalamocortical connectivity and integrity of thalami are central to attentional function. We hypothesize that DLB patients with marked and frequent fluctuating cognition (flCog) have a loss of thalamocortical connectivity, an intrinsic disruption to thalamic structure and imbalances in thalamic neurotransmitter levels. To test this, magnetic resonance imaging (MRI), diffusion tensor imaging (DTI) and proton MR spectroscopy on thalami were performed on 16 DLB, 16 Alzheimer's disease (AD) and 13 healthy subjects. MRI and DTI were combined to subdivide thalami according to their cortical connectivity and to investigate microstructural changes in connectivity-defined thalamic regions. Compared with controls, lower N-acetyl-aspartate/total creatine (NAA/tCr) and higher total choline/total creatine (tCho/tCr) values were observed within thalami of DLB patients. tCho/tCr increase was found within right thalamus of DLB patients as compared with AD. This increase correlated with severity and frequency of flCog. As compared with controls, DLB patients showed bilateral damage within thalamic regions projecting to prefrontal and parieto-occipital cortices, whereas AD patients showed bilateral alteration within thalamic region projecting to temporal cortex. We posit that microstructural thalamic damage and cholinergic imbalance may be central to the etiology of flCog in DLB.
authors.affiliation: Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and Institute for Advanced Biomedical Technologies (ITAB), "G. d'Annunzio" University, Chieti, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Delli Pizzi
authors.affiliation: Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and Institute for Advanced Biomedical Technologies (ITAB), "G. d'Annunzio" University, Chieti, Italy.
authors.forename: Raffaella
authors.initials: R
authors.lastname: Franciotti
authors.affiliation: Institute for Ageing and Health, Newcastle University, Campus for Ageing and Vitality, Newcastle upon Tyne NE4 5PL, UK.
authors.forename: John-Paul
authors.initials: JP
authors.lastname: Taylor
authors.affiliation: Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and.
authors.forename: Astrid
authors.initials: A
authors.lastname: Thomas
authors.affiliation: Department of Neuroscience, Imaging and Clinical Sciences Institute for Advanced Biomedical Technologies (ITAB), "G. d'Annunzio" University, Chieti, Italy.
authors.forename: Armando
authors.initials: A
authors.lastname: Tartaro
authors.affiliation: Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and.
authors.forename: Marco
authors.initials: M
authors.lastname: Onofrj
authors.affiliation: Department of Neuroscience, Imaging and Clinical Sciences Aging Research Centre, Ce.S.I. and.
authors.forename: Laura
authors.initials: L
authors.lastname: Bonanni
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000378:metabolism / Q000473:pathology / Q000523:psychology; D002540:Cerebral Cortex / Q000378:metabolism / Q000473:pathology; D003071:Cognition; D038524:Diffusion Magnetic Resonance Imaging; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000378:metabolism* / Q000473:pathology* / Q000523:psychology; D008297:Male; D009434:Neural Pathways / Q000378:metabolism / Q000473:pathology; D066244:Proton Magnetic Resonance Spectroscopy; D013788:Thalamus / Q000473:pathology*
keywords: attention; choline; dementia with Lewy bodies; fluctuating cognition; thalamus