title: Structural MRI correlates of the MMSE and pentagon copying test in Parkinson's disease.
abstract: BACKGROUND
  Cognitive impairment in Parkinson's disease (PD) is common and recent studies have focused on addressing the most suitable screening tool for its assessment. MMSE is commonly used in clinical practice and longitudinal studies found a relationship between the MMSE pentagon copying item and progression to dementia, but its neuroanatomical correlates have been poorly investigated. The aim of this study is to investigate the MRI structural correlates of the global MMSE and the pentagon item scores in PD patients in the absence of dementia.
  
  
  METHODS
  We selected a sample of 92 PD patients and 36 controls. MMSE was used as a global measure of cognitive status, and the pentagon copying test as a measure of visuospatial performance. FreeSurfer software was used to assess intergroup differences in cortical thickness (CTh) and global atrophy measures, as well as their relationship with cognitive performance.
  
  
  RESULTS
  Compared to controls, patients showed significant differences in measures of global atrophy, which correlated with performance on MMSE and the pentagon item. Regional differences in CTh were seen between PD patients and controls bilaterally in the temporo-parietal-occipital region. Patients with impaired performance compared with those of normal performance also showed CTh reductions in these regions.
  
  
  CONCLUSIONS
  Our results suggest MMSE and the pentagon item reflect brain changes which at a regional level involve mainly posterior regions. Correlates of the pentagon item were seen in the same regions where PD patients exhibited significant thinning, and involved more areas and bigger cluster sizes than the correlates of MMSE global scores.
authors.affiliation: Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Catalonia, Spain.
authors.forename: A I
authors.initials: AI
authors.lastname: Garcia-Diaz
authors.affiliation: Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Catalonia, Spain; Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Catalonia, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Segura
authors.affiliation: Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Catalonia, Spain; Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Catalonia, Spain.
authors.forename: H C
authors.initials: HC
authors.lastname: Baggio
authors.affiliation: Centro de Investigación en Red de Enfermedades Neurodegenerativas (CIBERNED), Hospital Clínic de Barcelona, Catalonia, Spain; Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Catalonia, Spain; Parkinson's Disease and Movement Disorders Unit, Neurology Service, Institut Clínic de Neurociències (ICN), Hospital Clínic de Barcelona, Catalonia, Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Marti
authors.affiliation: Centro de Investigación en Red de Enfermedades Neurodegenerativas (CIBERNED), Hospital Clínic de Barcelona, Catalonia, Spain; Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Catalonia, Spain; Parkinson's Disease and Movement Disorders Unit, Neurology Service, Institut Clínic de Neurociències (ICN), Hospital Clínic de Barcelona, Catalonia, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Valldeoriola
authors.affiliation: Centro de Investigación en Red de Enfermedades Neurodegenerativas (CIBERNED), Hospital Clínic de Barcelona, Catalonia, Spain; Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Catalonia, Spain; Parkinson's Disease and Movement Disorders Unit, Neurology Service, Institut Clínic de Neurociències (ICN), Hospital Clínic de Barcelona, Catalonia, Spain.
authors.forename: Y
authors.initials: Y
authors.lastname: Compta
authors.affiliation: Centro de Investigación en Red de Enfermedades Neurodegenerativas (CIBERNED), Hospital Clínic de Barcelona, Catalonia, Spain; Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Catalonia, Spain; Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Catalonia, Spain.
authors.forename: P
authors.initials: P
authors.lastname: Vendrell
authors.affiliation: Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Catalonia, Spain; Centre de Diagnòstic per la Imatge, Hospital Clínic, Barcelona, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Bargallo
authors.affiliation: Centro de Investigación en Red de Enfermedades Neurodegenerativas (CIBERNED), Hospital Clínic de Barcelona, Catalonia, Spain; Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Catalonia, Spain; Parkinson's Disease and Movement Disorders Unit, Neurology Service, Institut Clínic de Neurociències (ICN), Hospital Clínic de Barcelona, Catalonia, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Tolosa
authors.affiliation: Centro de Investigación en Red de Enfermedades Neurodegenerativas (CIBERNED), Hospital Clínic de Barcelona, Catalonia, Spain; Institute of Biomedical Research August Pi i Sunyer (IDIBAPS), Catalonia, Spain; Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Catalonia, Spain. Electronic address: cjunque@ub.edu.
authors.forename: C
authors.initials: C
authors.lastname: Junque
mesh_terms: D000368:Aged; D001284:Atrophy / Q000473:pathology; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D009778:Occipital Lobe / Q000473:pathology*; D010296:Parietal Lobe / Q000473:pathology*; D010300:Parkinson Disease / Q000150:complications* / Q000473:pathology*
keywords: Cortical thickness; Global atrophy; Parkinson disease; Pentagon copying test; Screening test