Publications and Research
Document Type
Article
Publication Date
2015
Abstract
In Parkinson’s disease (PD) degeneration of mesocortical dopaminergic projections may determine cognitive and behavioral symptoms. Choice reaction time task is related to attention, working memory, and goal-directed behavior. Such paradigm involves frontal cortical circuits receiving mesocortical dopamine which are affected early in PD. The aim of this study is to characterize the role of dopamine on the cognitive processes that precede movement in a reaction time paradigm in PD.We enrolled 16 newly diagnosed and untreated patientswith PDwithout cognitive impairment or depression and 10 control subjectswith essential tremor. They performed multiple-choice reaction time task with the right upper limb and brain 18F-DOPA PET/CT scan. A significant inverse correlation was highlighted between average reaction time and 18F-DOPA uptake in the left lateral orbitofrontal cortex. No correlations were found between reaction time and PD disease severity or between reaction time and 18F-DOPA uptake in controls. Our study shows that in PD, but not in controls, reaction time is inversely related to the levels of dopamine in the left lateral orbitofrontal cortex.This novel finding underlines the role of dopamine in the lateral orbitofrontal cortex in the early stages of PD, supporting a relation between the compensatory cortical dopamine and movement preparation.
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Comments
This article originally appeared in Parkinson's Disease, available at http://dx.doi.org/10.1155/2015/180940
© 2015 Lucio Marinelli et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.