title: Striatal and extrastriatal dopamine transporter levels relate to cognition in Lewy body diseases: an (11)C altropane positron emission tomography study.
abstract: BACKGROUND
  The biological basis of cognitive impairment in parkinsonian diseases is believed to be multifactorial. We investigated the contribution of dopamine deficiency to cognition in Parkinson disease (PD) and dementia with Lewy bodies (DLB) with dopamine transporter (DAT) imaging.
  
  
  METHODS
  We acquired (11)C altropane PET, magnetic resonance imaging and cognitive testing in 19 nondemented subjects with PD, 10 DLB and 17 healthy control subjects (HCS). We analyzed DAT concentration in putamen, caudate, anterior cingulate (AC), orbitofrontal and prefrontal regions, using the Standardized Uptake Volume Ratio with partial volume correction, and we related DAT concentration and global cortical thickness to neuropsychological performance.
  
  
  RESULTS
  DAT concentration in putamen and in caudate were similar in PD and DLB groups and significantly lower than in HCS. Reduced caudate DAT concentration was associated with worse Clinical Dementia Rating Scale-sum of boxes (CDR-SB) scores and visuospatial skills in DLB but not in PD or HCS groups. Adjusting for putamen DAT concentration, as a measure of severity of motor disease, caudate DAT concentration was lower in DLB than in PD. Higher AC DAT concentration was associated with lower putamen DAT concentration in DLB and with higher putamen DAT concentration in PD. Higher AC DAT concentration in DLB correlated with greater impairment in semantic memory and language.
  
  
  CONCLUSIONS
  Caudate and AC dopamine dysfunction contribute in opposing directions to cognitive impairment in DLB.
authors.affiliation: Department of Neurology, Massachusetts General Hospital, 15 Parkman St., Boston, MA 02114 USA ; MassGeneral Institute for Neurodegenerative Disease, 16th St., Building 114, Charlestown Navy Yard, Charlestown, MA 02129 USA ; Autonomous University of Barcelona, Medicine Doctoral Studies, Doctoral School, U Building, Autonomous University of Barcelona Campus, Bellaterra (Cerdanyola del Valles), 08193 Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Marquie
authors.affiliation: Department of Neurology, Massachusetts General Hospital, 15 Parkman St., Boston, MA 02114 USA.
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Locascio
authors.affiliation: Department of Neurology, Massachusetts General Hospital, 15 Parkman St., Boston, MA 02114 USA ; Department of Neurology, Brigham and Women's Hospital, 221 Longwood Avenue, Boston, MA 02115 USA.
authors.forename: Dorene M
authors.initials: DM
authors.lastname: Rentz
authors.affiliation: Department of Radiology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114 USA.
authors.forename: J Alex
authors.initials: JA
authors.lastname: Becker
authors.affiliation: Department of Radiology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114 USA ; Athinoula A. Martinos Center for Biomedical Imaging, 13th St., Building 149, Charlestown Navy Yard, Charlestown, MA 02129 USA.
authors.forename: Trey
authors.initials: T
authors.lastname: Hedden
authors.affiliation: Department of Neurology, Massachusetts General Hospital, 15 Parkman St., Boston, MA 02114 USA ; Department of Radiology, Massachusetts General Hospital, 55 Fruit St., Boston, MA 02114 USA.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Johnson
authors.affiliation: Department of Neurology, Massachusetts General Hospital, 15 Parkman St., Boston, MA 02114 USA.
authors.forename: John H
authors.initials: JH
authors.lastname: Growdon
authors.affiliation: Department of Neurology, Massachusetts General Hospital, 15 Parkman St., Boston, MA 02114 USA ; MassGeneral Institute for Neurodegenerative Disease, 16th St., Building 114, Charlestown Navy Yard, Charlestown, MA 02129 USA.
authors.forename: Stephen N
authors.initials: SN
authors.lastname: Gomperts