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Alterations in binding site density of dopamine transporter in the striatum, orbitofrontal cortex, and amygdala in early Parkinson's disease: Compartment analysis for β‐CFT binding with positron emission tomography
Author(s) -
Ouchi Yasuomi,
Yoshikawa Etuji,
Okada Hiroyuki,
Futatsubashi Masami,
Sekine Yoshimoto,
Iyo Masaomi,
Sakamoto Masanobu
Publication year - 1999
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/1531-8249(199905)45:5<601::aid-ana8>3.0.co;2-0
Subject(s) - orbitofrontal cortex , dopamine transporter , striatum , parkinson's disease , psychology , dopaminergic , positron emission tomography , neuroscience , amygdala , dopamine , binding potential , medicine , chemistry , prefrontal cortex , disease , cognition
We investigated changes in the kinetics in the binding of the dopamine transporter probe 2‐β‐carbomethoxy‐3β‐(4‐[ 11 C]fluorophenyl)tropane (β‐CFT) in living brain by compartmental analysis, using positron emission tomography in unmedicated patients with Parkinson's disease (PD) (Hoehn and Yahr stages I–II). With dynamic positron emission tomographic data from 90‐minute acquisitions and metabolite‐corrected arterial input functions, binding potentials ( k 3 / k 4 ) were calculated by using estimated rate constants ( K 1 − k 4 ). In this analysis, the magnitude of the distribution volume ( K 1 / k 2 ) measured in the cerebellum, in which specific binding is negligible, was used as a constrained value for fitting in binding regions. Statistics showed that k 3 / k 4 values in the striatum, the orbitofrontal cortex, and the amygdala were significantly lower in PD patients than in normal controls, whereas there were no differences in K 1 / k 2 ratios and structural volumes between the groups. Correlation analysis showed that the putaminal and orbitofrontal binding levels were correlated positively with motor and mentation scores, respectively, of the Unified Parkinson's Disease Rating Scale. These results indicated that not only the striatal but also the orbitofrontal and amygdalar presynaptic dopaminergic functions were altered in early PD. The reductions in these mesocortical/mesolimbic functions might contribute to the mental and behavioral impairment observed in PD. Ann Neurol 1999;45:601–610