Striatal and extrastriatal dysfunction in Parkinson's disease with dementia: a 6-[18F]fluoro-L-dopa PET study.
We investigated the relative differences in dopaminergic function through the whole brain in patients with Parkinson's disease without dementia (PD) and with dementia (PDD) using 6-[18F]fluoro-L-dopa (18F-dopa) PET and a voxel-by-voxel analysis. The 10 PD and 10 PDD patients were equivalently disabled, having mean scores of 3.2 +/- 0.6 and 3.2 +/- 0.7, respectively, on the Hoehn and Yahr rating scale. 18F-dopa influx constant (Ki) images of those patients and 15 normal age-matched subjects were transformed into standard stereotactic space. The significant differences between the groups (expressed in mean regional Ki values) were localized with statistical parametric mapping (SPM) on a voxel-by-voxel basis. Compared with the normal group, SPM localized declines of the 18F-dopa Ki bilaterally in the putamen, the right caudate nucleus and the left ventral midbrain for the PD group (P < 0.01, corrected). Compared with the normal group, the PDD group showed reduced 18F-dopa Ki bilaterally in the striatum, midbrain and anterior cingulate area (P < 0.01, corrected). A relative difference in 18F-dopa uptake between PD and PDD was the bilateral decline in the anterior cingulate area and ventral striatum and in the right caudate nucleus in the PDD group (P < 0.001, corrected). Accordingly, we conclude that dementia in PD is associated with impaired mesolimbic and caudate dopaminergic function.
Ito
Kengo
K
Department of Biofunctional Research, National Institute for Longevity Sciences, Obu, Japan. kito@nils.go.jp
Nagano-Saito
Atsuko
A
Kato
Takashi
T
Arahata
Yutaka
Y
Nakamura
Akinori
A
Kawasumi
Yasuhiro
Y
Hatano
Kentaro
K
Abe
Yuji
Y
Yamada
Takako
T
Kachi
Teruhiko
T
Brooks
David J
DJ
D000368:Aged; D000704:Analysis of Variance; D003342:Corpus Striatum / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003704:Dementia / Q000000981:diagnostic imaging* / Q000503:physiopathology; D015259:Dopamine Agents; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D007980:Levodopa; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014055:Tomography, Emission-Computed / Q000379:methods / Q000706:statistics & numerical data
D015259:Dopamine Agents; D005462:Fluorine Radioisotopes; D007980:Levodopa