JOAO RICARDO SATO
Projetos de Pesquisa
Unidades Organizacionais
LIM/44 - Laboratório de Ressonância Magnética em Neurorradiologia, Hospital das Clínicas, Faculdade de Medicina
2 resultados
Resultados de Busca
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- Altered Functional Connectivity Between Precuneus and Motor Systems in Parkinson's Disease Patients(2017) THIBES, Raissa Benocci; NOVAES, Natalia P.; LUCATO, Leandro T.; CAMPANHOLO, Kenia R.; MELO, Luciano M.; LEITE, Claudia C.; AMARO JR., Edson; BARBOSA, Egberto Reis; BOR-SENG-SHU, Edson; CARDOSO, Ellison Fernando; SATO, Joao RicardoParkinson's disease (PD) is a neurodegenerative disorder that affects motor skills and cognition. As brain structure and function are compromised, functional magnetic resonance imaging (fMRI) can be a helpful tool to further investigate how intrinsic connectivity is impaired on the disease. The precuneus and medial prefrontal cortex (mPFC) are hub regions involved on the default mode network (DMN), a system that is active during rest and related to cognitive processes. We hypothesized that PD patients would present a decrease in functional connectivity among these two regions and the rest of the brain. Our goal was to identify regions in which functional connectivity to precuneus and mPFC was altered in PD. This study was based on resting-state fMRI data from 37 healthy subjects and 55 PD patients. Precuneus and mPFC were selected as seed regions in a whole brain functional connectivity mapping. As expected, we found abnormal connectivity from precuneus to motor system regions in PD patients, pointing toward a decreased connectivity in the disease. No significant group effects were found for the mPFC. Our findings suggest that internetwork connectivity from DMN to motor system is impaired in PD.
- Association Between Fractional Amplitude of Low-Frequency Spontaneous Fluctuation and Degree Centrality in Children and Adolescents(2019) SATO, Joao Ricardo; JR, Claudinei Eduardo Biazoli; MOURA, Luciana Monteiro; CROSSLEY, Nicolas; ZUGMAN, Andre; PICON, Felipe Almeida; HOEXTER, Marcelo Queiroz; JR, Edson Amaro; MIGUEL, Euripedes Constantino; ROHDE, Luis Augusto; BRESSAN, Rodrigo Affonseca; JACKOWSKI, Andrea ParolinThe fractional amplitude of low-frequency fluctuations (fALFFs) of the BOLD signal have been successfully applied as exploratory tools in neuroimaging. This metric has been useful in mapping brain functional changes in many clinical populations. However, little is known about the neurophysiological correlates of fALFF. This study aimed at demonstrating that fALFF is related to local network centrality during childhood and adolescence. The establishment of this relationship is fundamental to provide a more meaningful explanation to previous clinical and neurodevelopmental studies based on fALFF. Our findings show a correlation of similar to 0.5 between these two metrics at a group level, which is a finding replicated in four large independent samples. However, when considering the across-subject and intra-subject correlations between the two metrics, the correlation is much lower, probably due to the low signal-to-noise ratio. Moreover, we found that regions with high fALFF and degree centrality overlapped modestly, particularly the posterior cingulate/precuneus and lateral parietal cortices.