title: Altered functional connectivity in the default mode network is associated with cognitive impairment and brain anatomical changes in Parkinson's disease.
abstract: To assess whether functional neural connectivity is disrupted between the regions of the default mode network (DMN) in Parkinson's disease (PD) and how this connectivity is related to cognition, brain gray matter structure and white matter integrity and diffusivity.
  
  
  
  Thirty-seven PD patients and 16 healthy controls were evaluated, using resting-state functional magnetic resonance imaging (MRI), T1-weighted MRI, diffusion-weighted imaging and a battery of cognitive tests. Functional connectivity between the regions of the DMN, specifically in the precuneus, anterior and posterior cingulate, medial prefrontal and temporal and inferior parietal cortices was assessed with seed-to-voxel connectivity; gray matter volume and white matter values were determined using voxel-based morphometry and tract-based spatial statistics.
  
  
  
  Reduced functional connectivity was observed between the posterior cingulate and medial temporal lobe in PD. Lower cognitive performance, gray matter loss in posterior, medial temporal and parietal areas, and fractional anisotropy reduction in the white matter adjacent to DMN regions were also observed in PD patients compared with healthy controls. Lower DMN functional connectivity correlated with lower verbal and visual memory and visual abilities performance in PD. In addition, lower DMN functional connectivity correlated with lower gray matter volume in the posterior cingulate and precuneus, and with lower white matter fractional anisotropy of the inferior longitudinal and posterior cingulate fasciculi in PD.
  
  
  
  By combining different neuroimaging techniques and cognitive data, results showed that functional connectivity alteration between the regions of the DMN is associated with lower cognitive performance and gray and white matter abnormalities in PD.
authors.affiliation: Department of Methods and Experimental Psychology, Faculty of Psychology and Education, University of Deusto, Bilbao, Spain.
authors.forename: Olaia
authors.initials: O
authors.lastname: Lucas-Jiménez
authors.affiliation: Department of Methods and Experimental Psychology, Faculty of Psychology and Education, University of Deusto, Bilbao, Spain.
authors.forename: Natalia
authors.initials: N
authors.lastname: Ojeda
authors.affiliation: Department of Methods and Experimental Psychology, Faculty of Psychology and Education, University of Deusto, Bilbao, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: Peña
authors.affiliation: Department of Methods and Experimental Psychology, Faculty of Psychology and Education, University of Deusto, Bilbao, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Díez-Cirarda
authors.affiliation: OSATEK, MR Unit Hospital of Galdakao, Galdakao, Usansolo, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Cabrera-Zubizarreta
authors.affiliation: Neurodegenerative Diseases Group, Biocruces Health Research Institute, University of Basque Country, Barakaldo, Spain.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Gómez-Esteban
authors.affiliation: Department of Neurology, Hospital of Galdakao, Galdakao, Usansolo, Spain.
authors.forename: María Ángeles
authors.initials: MÁ
authors.lastname: Gómez-Beldarrain
authors.affiliation: Department of Methods and Experimental Psychology, Faculty of Psychology and Education, University of Deusto, Bilbao, Spain. Electronic address: naroa.ibarretxe@deusto.es.
authors.forename: Naroa
authors.initials: N
authors.lastname: Ibarretxe-Bilbao
mesh_terms: D000368:Aged; D016880:Anisotropy; D001931:Brain Mapping; D003072:Cognition Disorders / Q000209:etiology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D008959:Models, Neurological; D009434:Neural Pathways / Q000000981:diagnostic imaging; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010300:Parkinson Disease / Q000150:complications* / Q000473:pathology*; D012146:Rest; D066127:White Matter / Q000000981:diagnostic imaging*
chemical_list: D010100:Oxygen
keywords: Cognitive impairment; Default mode network; Diffusion-weighted imaging; Functional connectivity; Gray matter; Parkinson's disease