title: Changes in anatomical and functional connectivity of Parkinson's disease patients according to cognitive status.
abstract: OBJECTIVE
  This study assesses the patterns of structural and functional connectivity damage in patients with Parkinson's disease dementia (PDD) compared with cognitively unimpaired Parkinson's disease patients (PD-Cu) and healthy controls (HC).
  
  
  METHODS
  Resting state functional magnetic resonance imaging (rs-fMRI) and diffusion tensor magnetic resonance imaging (DTI) scans were obtained from 30 PD and 21 sex- and age-matched HC. The between-group difference in posterior cingulate (PCC) functional connectivity (FC) was performed to assess FC dysfunction. Atlas-based spatial statistics of DTI was applied to compare White matter (WM) fibers impairment between groups.
  
  
  RESULTS
  (1) Functional connectivity: (1) PD-Cu compared with HC showed a decreased PCC functional connectivity of the right medial temporal lobe (MTL). In addition, PCC-right MTL connectivity strength of PD was significantly correlated with Montreal Cognitive Assessment (MoCA) score. (2) PDD group shows a decreased FC of PCC-right parahippocampa compared with PD-Cu group; while show a widespread decreased PCC FC compared with HC group. (2) Anatomical connectivity: (1) Relative to PD-Cu, significant lower FA values were found in the left hippocampus in PDD. (2) PDD showed higher MD values in a widespread WM regions compared with PD-Cu and HC. (3) Positive correlation was observed between MoCA score and FA value of left inferior longitudinal and hippocampus, and bilateral superior longitudinal fasciculus in PD.
  
  
  CONCLUSIONS
  Cognitive decline in PD is associated with FC damage of PCC-right MTL and microstructural damage of left hippocampus. Nevertheless, combining fMRI and DTI method may provide markers able to contribute to the prediction of PDD.
authors.affiliation: Department of Radiology, The First Hospital, China Medical University, #155, Nanjing North St., Heping Dist., Shenyang, Liaoning 110001, China. Electronic address: cbyzgyk@126.com.
authors.forename: Boyu
authors.initials: B
authors.lastname: Chen
authors.affiliation: Department of Radiology, The First Hospital, China Medical University, #155, Nanjing North St., Heping Dist., Shenyang, Liaoning 110001, China. Electronic address: fanguog@sina.com.
authors.forename: Guo Guang
authors.initials: GG
authors.lastname: Fan
authors.affiliation: Department of Radiology, The First Hospital, China Medical University, #155, Nanjing North St., Heping Dist., Shenyang, Liaoning 110001, China. Electronic address: liuhu1234567@126.com.
authors.forename: Hu
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Radiology, The First Hospital, China Medical University, #155, Nanjing North St., Heping Dist., Shenyang, Liaoning 110001, China. Electronic address: jelly_66@126.com.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Wang
mesh_terms: D003072:Cognition Disorders / Q000150:complications* / Q000503:physiopathology; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006179:Gyrus Cinguli / Q000473:pathology; D006624:Hippocampus / Q000473:pathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000503:physiopathology; D010300:Parkinson Disease / Q000150:complications* / Q000503:physiopathology; D066127:White Matter / Q000033:anatomy & histology / Q000473:pathology* / Q000503:physiopathology*
keywords: Anatomical connectivity; Dementia; Diffusion tensor MRI; Functional connectivity; Parkinson's disease; Resting state fMRI