Striatal and extrastriatal dysfunction in Parkinson's disease with dementia: a 6-[18F]fluoro-L-dopa PET study

• Published in: Brain (London, England : 1878) England : 1878), 2002-06, Vol.125 (Pt 6), p.1358-1365
• Main Authors: ITO, Kengo, NAGANO-SAITO, Atsuko, BROOKS, David J, KATO, Takashi, ARAHATA, Yutaka, NAKAMURA, Akinori, KAWASUMI, Yasuhiro, HATANO, Kentaro, ABE, Yuji, YAMADA, Takako, KACHI, Teruhiko
• Format: Article
• Language: English
• Subjects: Aged; Analysis of Variance; Biological and medical sciences; Corpus Striatum - diagnostic imaging; Corpus Striatum - physiopathology; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Dementia; Dementia - diagnostic imaging; Dementia - physiopathology; Dopamine Agents; Female; Fluorine Radioisotopes; Humans; Levodopa; Male; Medical sciences; Middle Aged; Neurology; Parkinson Disease - diagnostic imaging; Parkinson Disease - physiopathology; Tomography, Emission-Computed - methods; Tomography, Emission-Computed - statistics & numerical data
• ISSN: 0006-8950; 1460-2156
• DOI: 10.1093/brain/awf134

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.