title: Abnormal metabolic brain network associated with Parkinson's disease: replication on a new European sample.
abstract: OBJECTIVE
  The purpose of this study was to identify the specific metabolic brain pattern characteristic for Parkinson's disease (PD): Parkinson's disease-related pattern (PDRP), using network analysis of [18F]-fluorodeoxyglucose positron emission tomography (FDG-PET) brain images in a cohort of Slovenian PD patients.
  
  
  METHODS
  Twenty PD patients (age 70.1 ± 7.8 years, Movement Disorder Society Unified Parkinson's Disease Motor Rating Scale (MDS-UPDRS-III) 38.3 ± 12.2; disease duration 4.3 ± 4.1 years) and 20 age-matched normal controls (NCs) underwent FDG-PET brain imaging. An automatic voxel-based scaled subprofile model/principal component analysis (SSM/PCA) was applied to these scans for PDRP-Slovenia identification.
  
  
  RESULTS
  The pattern was characterized by relative hypermetabolism in pallidum, putamen, thalamus, brain stem, and cerebellum associated with hypometabolism in sensorimotor cortex, posterior parietal, occipital, and frontal cortices. The expression of PDRP-Slovenia discriminated PD patients from NCs (p < 0.0001) and correlated positively with patients' clinical score (MDS-UPDRS-III, p = 0.03). Additionally, its topography agrees well with the original PDRP (p < 0.001) identified in American cohort of PD patients. We validated the PDRP-Slovenia expression on additional FDG-PET scans of 20 PD patients, 20 NCs, and 25 patients with atypical parkinsonism (AP). We confirmed that the expression of PDRP-Slovenia manifests good diagnostic accuracy with specificity and sensitivity of 85-90% at optimal pattern expression cutoff for discrimination of PD patients and NCs and is not expressed in AP.
  
  
  CONCLUSIONS
  PDRP-Slovenia proves to be a robust and reproducible functional imaging biomarker independent of patient population. It accurately differentiates PD patients from NCs and AP and correlates well with the clinical measure of PD progression.
authors.affiliation: Department of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors.forename: Petra
authors.initials: P
authors.lastname: Tomše
authors.affiliation: Department of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors.forename: Luka
authors.initials: L
authors.lastname: Jensterle
authors.affiliation: Department of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors.forename: Marko
authors.initials: M
authors.lastname: Grmek
authors.affiliation: Department of Nuclear Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia.
authors.forename: Katja
authors.initials: K
authors.lastname: Zaletel
authors.affiliation: Department of Neurology, University Medical Centre Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia.
authors.forename: Zvezdan
authors.initials: Z
authors.lastname: Pirtošek
authors.affiliation: Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: Vijay
authors.initials: V
authors.lastname: Dhawan
authors.affiliation: Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: Shichun
authors.initials: S
authors.lastname: Peng
authors.affiliation: Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: David
authors.initials: D
authors.lastname: Eidelberg
authors.affiliation: Center for Neurosciences, The Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: Yilong
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Neurology, University Medical Centre Ljubljana, Zaloška cesta 2, 1000 Ljubljana, Slovenia. maja.trost@kclj.si.
authors.forename: Maja
authors.initials: M
authors.lastname: Trošt
mesh_terms: D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000378:metabolism*; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000378:metabolism*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Atypical parkinsonism; FDG-PET; Parkinson’s disease; Principal component analysis; Specific metabolic brain network