title: Functional brain changes in early Parkinson's disease during motor response and motor inhibition.
abstract: Motor impairment represents the main clinical feature of Parkinson's disease (PD). Cognitive deficits are also frequently observed in patients with PD, with a prominent involvement of executive functions and visuo-spatial abilities. We used event-related functional MRI (fMRI) and a paradigm based on visual attention and motor inhibition (Go/NoGO-task) to investigate brain activations in 13 patients with early PD in comparison with 11 healthy controls. The two groups did not report behavioural differences in task performance. During motor inhibition (NoGO-effect), PD patients compared to controls showed an increased activation in the prefrontal cortex and in the basal ganglia. They also showed a reduced and less coherent hemodynamic response in the occipital cortex. These results indicate that specific cortico-subcortical functional changes, involving not only the fronto-striatal network but also the temporal-occipital cortex, are already present in patients with early PD and no clinical evidence of cognitive impairment. We discuss our findings in terms of compensatory mechanisms (fronto-striatal changes) and preclinical signs of visuo-perceptual deficits and visual hallucinations.
authors.affiliation: Don Carlo Gnocchi Foundation, Scientific Institute and University, IRCCS, 20148 Milan, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Baglio
authors.forename: Valeria
authors.initials: V
authors.lastname: Blasi
authors.forename: Andrea
authors.initials: A
authors.lastname: Falini
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Farina
authors.forename: Federica
authors.initials: F
authors.lastname: Mantovani
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Olivotto
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Scotti
authors.forename: Raffaello
authors.initials: R
authors.lastname: Nemni
authors.forename: Marco
authors.initials: M
authors.lastname: Bozzali
mesh_terms: D000368:Aged; D001921:Brain / Q000098:blood supply* / Q000503:physiopathology*; D001931:Brain Mapping; D003072:Cognition Disorders / Q000175:diagnosis / Q000209:etiology; D003657:Decision Making / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D007266:Inhibition, Psychological; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010300:Parkinson Disease / Q000150:complications / Q000473:pathology*
chemical_list: D010100:Oxygen