TY - JOUR
T1 - Orbitofrontal 18F-DOPA Uptake and Movement Preparation in Parkinson's Disease
AU - Marinelli, Lucio
AU - Piccardo, Arnoldo
AU - Mori, Laura
AU - Morbelli, Silvia
AU - Girtler, Nicola
AU - Castaldi, Antonio
AU - Picco, Agnese
AU - Trompetto, Carlo
AU - Ghilardi, Maria Felice
AU - Abbruzzese, Giovanni
AU - Nobili, Flavio
PY - 2015
Y1 - 2015
N2 - 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 patients with PD without cognitive impairment or depression and 10 control subjects with 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.
AB - 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 patients with PD without cognitive impairment or depression and 10 control subjects with 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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U2 - 10.1155/2015/180940
DO - 10.1155/2015/180940
M3 - Article
VL - 2015
JO - npj Parkinson's Disease
JF - npj Parkinson's Disease
SN - 2090-8083
M1 - 180940
ER -