Functional brain changes in early Parkinson's disease during motor response and motor inhibition.
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.
Baglio
Francesca
F
Don Carlo Gnocchi Foundation, Scientific Institute and University, IRCCS, 20148 Milan, Italy.
Blasi
Valeria
V
Falini
Andrea
A
Farina
Elisabetta
E
Mantovani
Federica
F
Olivotto
Fabrizio
F
Scotti
Giuseppe
G
Nemni
Raffaello
R
Bozzali
Marco
M
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*
D010100:Oxygen