Abnormal visual activation in Parkinson's disease patients.
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.
Cardoso
Ellison Fernando
EF
NIF, LIM-44, Department of Radiology, University of São Paulo, São Paulo, Brazil. lim@usp.br
Fregni
Felipe
F
Maia
Fernanda Martins
FM
Melo
Luciano M
LM
Sato
João R
JR
Cruz
Antonio Cesário
AC
Bianchi
Edno Tales
ET
Fernandes
Danilo Botelho
DB
Monteiro
Mário Luiz Ribeiro
ML
Barbosa
Egberto Reis
ER
Amaro
Edson
E
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
D010100:Oxygen