title: Abnormal visual activation in Parkinson's disease patients.
abstract: Among nonmotor symptoms observed in Parkinson's disease (PD) dysfunction in the visual system, including hallucinations, has a significant impact in their quality of life. To further explore the visual system in PD patients we designed two fMRI experiments comparing 18 healthy volunteers with 16 PD patients without visual complaints in two visual fMRI paradigms: the flickering checkerboard task and a facial perception paradigm. PD patients displayed a decreased activity in the primary visual cortex (Broadmann area 17) bilaterally as compared to healthy volunteers during flickering checkerboard task and increased activity in fusiform gyrus (Broadmann area 37) during facial perception paradigm. Our findings confirm the notion that PD patients show significant changes in the visual cortex system even before the visual symptoms are clinically evident. Further studies are necessary to evaluate the contribution of these abnormalities to the development visual symptoms in PD.
authors.affiliation: NIF, LIM-44, Department of Radiology, University of São Paulo, São Paulo, Brazil. lim@usp.br
authors.forename: Ellison Fernando
authors.initials: EF
authors.lastname: Cardoso
authors.forename: Felipe
authors.initials: F
authors.lastname: Fregni
authors.forename: Fernanda Martins
authors.initials: FM
authors.lastname: Maia
authors.forename: Luciano M
authors.initials: LM
authors.lastname: Melo
authors.forename: João R
authors.initials: JR
authors.lastname: Sato
authors.forename: Antonio Cesário
authors.initials: AC
authors.lastname: Cruz
authors.forename: Edno Tales
authors.initials: ET
authors.lastname: Bianchi
authors.forename: Danilo Botelho
authors.initials: DB
authors.lastname: Fernandes
authors.forename: Mário Luiz Ribeiro
authors.initials: ML
authors.lastname: Monteiro
authors.forename: Egberto Reis
authors.initials: ER
authors.lastname: Barbosa
authors.forename: Edson
authors.initials: E
authors.lastname: Amaro
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D005145:Face; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination / Q000379:methods; D009483:Neuropsychological Tests; D010100:Oxygen / Q000097:blood; D010300:Parkinson Disease / Q000150:complications* / Q000473:pathology*; D010364:Pattern Recognition, Visual / Q000502:physiology*; D010468:Perceptual Disorders / Q000209:etiology*; D010775:Photic Stimulation / Q000379:methods; D013223:Statistics as Topic; D014793:Visual Cortex / Q000098:blood supply / Q000503:physiopathology*; D014795:Visual Pathways / Q000098:blood supply / Q000503:physiopathology
chemical_list: D010100:Oxygen