title: Cognitive impairment and resting-state network connectivity in Parkinson's disease.
abstract: The purpose of this work was to evaluate changes in the connectivity patterns of a set of cognitively relevant, dynamically interrelated brain networks in association with cognitive deficits in Parkinson's disease (PD) using resting-state functional MRI. Sixty-five nondemented PD patients and 36 matched healthy controls were included. Thirty-four percent of PD patients were classified as having mild cognitive impairment (MCI) based on performance in attention/executive, visuospatial/visuoperceptual (VS/VP) and memory functions. A data-driven approach using independent component analysis (ICA) was used to identify the default-mode network (DMN), the dorsal attention network (DAN) and the bilateral frontoparietal networks (FPN), which were compared between groups using a dual-regression approach controlling for gray matter atrophy. Additional seed-based analyses using a priori defined regions of interest were used to characterize local changes in intranetwork and internetwork connectivity. Structural group comparisons through voxel-based morphometry and cortical thickness were additionally performed to assess associated gray matter atrophy. ICA results revealed reduced connectivity between the DAN and right frontoinsular regions in MCI patients, associated with worse performance in attention/executive functions. The DMN displayed increased connectivity with medial and lateral occipito-parietal regions in MCI patients, associated with worse VS/VP performance, and with occipital reductions in cortical thickness. In line with data-driven results, seed-based analyses mainly revealed reduced within-DAN, within-DMN and DAN-FPN connectivity, as well as loss of normal DAN-DMN anticorrelation in MCI patients. Our findings demonstrate differential connectivity changes affecting the networks evaluated, which we hypothesize to be related to the pathophysiological bases of different types of cognitive impairment in PD.
authors.affiliation: Departament de Psiquiatria i Psicobiologia Clínica, Universitat de Barcelona, Barcelona, Catalonia, Spain.
authors.forename: Hugo-Cesar
authors.initials: HC
authors.lastname: Baggio
authors.forename: Bàrbara
authors.initials: B
authors.lastname: Segura
authors.forename: Roser
authors.initials: R
authors.lastname: Sala-Llonch
authors.forename: Maria-José
authors.initials: MJ
authors.lastname: Marti
authors.forename: Francesc
authors.initials: F
authors.lastname: Valldeoriola
authors.forename: Yaroslau
authors.initials: Y
authors.lastname: Compta
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tolosa
authors.forename: Carme
authors.initials: C
authors.lastname: Junqué
mesh_terms: D000368:Aged; D001288:Attention; D001921:Brain / Q000098:blood supply / Q000473:pathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000209:etiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000098:blood supply / Q000473:pathology; D009434:Neural Pathways / Q000098:blood supply / Q000473:pathology; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010300:Parkinson Disease / Q000150:complications* / Q000473:pathology*; D012146:Rest
chemical_list: D010100:Oxygen
keywords: Parkinson's disease; fMRI; mild cognitive impairment; resting-state connectivity