Dementia in Parkinson disease: Functional imaging of cholinergic and dopaminergic pathways.
Hilker, R MD *; Thomas, A V. MD *; Klein, J C. MD; Weisenbach, S MD; Kalbe, E PhD; Burghaus, L MD; Jacobs, A H. MD; Herholz, K MD; Heiss, W D. MD
65(11):1716-1722, December 13, 2005.
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Objective: To assess neurochemical deficits in patients with Parkinson disease (PD) associated dementia (PDD) in vivo.
Methods: The authors performed combined PET with N-[11C]-methyl-4-piperidyl acetate (MP4A) and 18F-fluorodopa (FDOPA) for evaluation of cholinergic and dopaminergic transmitter changes in 17 non-demented patients with PD and 10 patients with PDD. Data were compared to 31 age-matched controls by a combined region-of-interest and voxel-based Statistical Parametric Mapping analysis.
Results: The striatal FDOPA uptake was significantly decreased in PD and PDD without differences between the groups. The global cortical MP4A binding was severely reduced in PDD (29.7%, p < 0.001 vs controls) and moderately decreased in PD (10.7%, p < 0.01 vs controls). The PDD group had lower parietal MP4A uptake rates than did patients with PD. Frontal and temporo-parietal cortices showed a significant covariance of striatal FDOPA reduction and decreased MP4A binding in patients with PDD.
Conclusions: While non-demented patients with Parkinson disease had a moderate cholinergic dysfunction, subjects with Parkinson disease associated dementia (PDD) presented with a severe cholinergic deficit in various cortical regions. The finding of a closely associated striatal FDOPA and cortical MP4A binding reduction suggests a common disease process leading to a complex transmitter deficiency syndrome in PDD.
(C) 2005 American Academy of Neurology