title: Orbitofrontal (18) F-DOPA Uptake and Movement Preparation in Parkinson's Disease.
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 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 (18)F-DOPA PET/CT scan. A significant inverse correlation was highlighted between average reaction time and (18)F-DOPA uptake in the left lateral orbitofrontal cortex. No correlations were found between reaction time and PD disease severity or between reaction time and (18)F-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.
authors.affiliation: Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo Daneo 3, 16132 Genoa, Italy.
authors.forename: Lucio
authors.initials: L
authors.lastname: Marinelli
authors.affiliation: Nuclear Medicine Unit, Galliera Hospital, Mura delle Cappuccine 14, 16128 Genoa, Italy.
authors.forename: Arnoldo
authors.initials: A
authors.lastname: Piccardo
authors.affiliation: Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo Daneo 3, 16132 Genoa, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Mori
authors.affiliation: Nuclear Medicine Unit, Department of Health Sciences, IRCCS AOU San Martino, IST, University of Genoa, Largo Rosanna Benzi 10, 16132 Genoa, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Morbelli
authors.affiliation: Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo Daneo 3, 16132 Genoa, Italy ; Clinical Psychology and Psychotherapy Unit, IRCCS AOU San Martino, IST, Largo Rosanna Benzi 10, 16132 Genoa, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Girtler
authors.affiliation: Department of Diagnostic and Interventional Neuroradiology, Galliera Hospital, Mura delle Cappuccine 14, 16128 Genoa, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Castaldi
authors.affiliation: Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo Daneo 3, 16132 Genoa, Italy.
authors.forename: Agnese
authors.initials: A
authors.lastname: Picco
authors.affiliation: Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo Daneo 3, 16132 Genoa, Italy.
authors.forename: Carlo
authors.initials: C
authors.lastname: Trompetto
authors.affiliation: Department of Physiology, Pharmacology and Neuroscience, City University of New York Medical School, 160 Convent Avenue, New York, NY 10031, USA.
authors.forename: Maria Felice
authors.initials: MF
authors.lastname: Ghilardi
authors.affiliation: Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo Daneo 3, 16132 Genoa, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Abbruzzese
authors.affiliation: Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Largo Daneo 3, 16132 Genoa, Italy.
authors.forename: Flavio
authors.initials: F
authors.lastname: Nobili