title: Metabolic Topology of Neurodegenerative Disorders: Influence of Cognitive and Motor Deficits.
abstract: Parkinson disease with and without dementia (PDD and PD, respectively), dementia with Lewy bodies (DLB), and Alzheimer dementia (AD) traditionally have been viewed as distinct clinical and pathologic entities. However, intriguing overlaps in biochemical, clinical, and imaging findings question the concept of distinct entities and suggest a continuous spectrum in which individual patients express PD-typical patterns and AD-typical patterns to a variable degree.
  
  
  METHODS
  Following this concept, we built a topological map based on regional patterns of the cerebral metabolic rate of glucose as measured with (18)F-FDG PET to rank and localize single subjects' disease status according to PD-typical (PD vs. controls) and AD-typical (AD vs. controls) pattern expression in patients clinically characterized as PD, PDD, DLB, amnestic mild cognitive impairment, and AD.
  
  
  RESULTS
  The topology generally confirmed an indivisible spectrum of disease manifestation according to 2 separable expression patterns. The expression values derived from the first pattern were highly correlated with individual cognitive, but not motor, disability. The opposite was found for the corresponding expression values of the second pattern.
  
  
  CONCLUSIONS
  The metabolic imaging analysis supports the notion that there is a continuous spectrum of neurodegeneration between AD and PD. Furthermore, PDD and DLB may in fact represent 1 overlapping disease entity, characterized by the presence of mixed neuropathology and only different by the time course.
authors.affiliation: Department of Neurology, Kiel University, Kiel, Germany o.granert@neurologie.uni-kiel.de.
authors.forename: Oliver
authors.initials: O
authors.lastname: Granert
authors.affiliation: Department of Nuclear Medicine, University of Cologne, Cologne, Germany.
authors.forename: Alexander E
authors.initials: AE
authors.lastname: Drzezga
authors.affiliation: Department of Radiology, Bonn University, Bonn, Germany.
authors.forename: Henning
authors.initials: H
authors.lastname: Boecker
authors.affiliation: Neuroepidemiology and Ageing Research Unit, Imperial College of Science, Technology and Medicine, London, United Kingdom Cognitive Impairment and Dementia Services, West London Mental Health NHS Trust, London, United Kingdom Department of Psychiatry, TU Munich, Munich, Germany.
authors.forename: Robert
authors.initials: R
authors.lastname: Perneczky
authors.affiliation: Department of Psychiatry, TU Munich, Munich, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Kurz
authors.affiliation: Department of Neurology, Kiel University, Kiel, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Götz
authors.affiliation: Department of Neurology, Kiel University, Kiel, Germany.
authors.forename: Thilo
authors.initials: T
authors.lastname: van Eimeren
authors.affiliation: Department of Psychiatry, Kiel University, Kiel, Germany; and LVR Clinic Cologne, Academic Teaching Hospital, University of Cologne, Cologne, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Häussermann
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000378:metabolism / Q000523:psychology; D001931:Brain Mapping; D003071:Cognition; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000378:metabolism / Q000523:psychology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D020961:Lewy Body Disease / Q000000981:diagnostic imaging / Q000378:metabolism / Q000523:psychology; D008297:Male; D009069:Movement Disorders / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000523:psychology*; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000523:psychology*; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000378:metabolism / Q000523:psychology; D010301:Parkinson Disease, Postencephalitic / Q000000981:diagnostic imaging / Q000378:metabolism / Q000523:psychology; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Alzheimer; FDG PET; Parkinson; dementia; motor deficits