title: Parkinson's disease cognitive network correlates with caudate dopamine.
abstract: Prior evidence has suggested a link between caudate dopaminergic functioning and cognition in Parkinson's disease (PD). In this dual tracer study we analyzed the relationship between nigrostriatal dopaminergic dysfunction and the expression of the previously validated PD cognition-related metabolic pattern (PDCP). In this study, 17 non-demented PD patients underwent positron emission tomography (PET) imaging with [(18)F]-fluorodeoxyglucose to measure PDCP expression, and [(18)F]-fluoropropyl-β-CIT (FPCIT) to measure dopamine transporter (DAT) binding. Automated voxel-by-voxel searches of the FPCIT PET volumes were performed to identify regions in which DAT binding significantly correlated with PDCP expression values. The findings were validated using prespecified anatomical regions-of-interest (ROIs). Voxel-wise interrogation of the FPCIT PET scans revealed a single significant cluster in which DAT binding correlated with PDCP expression (p<0.05, corrected). This cluster was localized to the left caudate nucleus; an analogous correlation (r=-0.63, p<0.01) was also present in the "mirror" region of the right hemisphere. These findings were confirmed by the presence of a significant correlation (r=-0.67, p<0.005) between PDCP expression and DAT binding in caudate ROIs, which survived adjustment for age, disease duration, and clinical severity ratings. Correlation between caudate DAT binding and subject expression of the PD motor-related metabolic pattern was not significant (p>0.21). In summary, this study demonstrates a significant relationship between loss of dopaminergic input to the caudate nucleus and the expression of a cognition-related disease network in unmedicated PD patients. These baseline measures likely function in concert to determine the cognitive effects of dopaminergic therapy in PD.
authors.affiliation: Center for Neurosciences, The Feinstein Institute for Medical Research, 350 Community Drive, Manhasset, NY 11030, USA. mniethamme@nshs.edu
authors.forename: Martin
authors.initials: M
authors.lastname: Niethammer
authors.forename: Chris C
authors.initials: CC
authors.lastname: Tang
authors.forename: Yilong
authors.initials: Y
authors.lastname: Ma
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Mattis
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Ko
authors.forename: Vijay
authors.initials: V
authors.lastname: Dhawan
authors.forename: David
authors.initials: D
authors.lastname: Eidelberg
mesh_terms: D002421:Caudate Nucleus / Q000000981:diagnostic imaging* / Q000378:metabolism; D004298:Dopamine / Q000032:analysis / Q000378:metabolism*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000378:metabolism; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D014326:Tropanes
chemical_list: D019275:Radiopharmaceuticals; D014326:Tropanes; D019788:Fluorodeoxyglucose F18; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane; D004298:Dopamine