JOAO RICARDO SATO
Projetos de Pesquisa
Unidades Organizacionais
LIM/44 - Laboratório de Ressonância Magnética em Neurorradiologia, Hospital das Clínicas, Faculdade de Medicina
20 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 20
- Commentary: Functional connectome fingerprint: identifying individuals using patterns of brain connectivity(2017) BIAZOLI JR., Claudinei E.; SALUM, Giovanni A.; PAN, Pedro M.; ZUGMAN, Andre; AMARO JR., Edson; ROHDE, Luis A.; MIGUEL, Euripedes C.; JACKOWSKI, Andrea P.; BRESSAN, Rodrigo A.; SATO, Joao R.
conferenceObject Treatment Response Prediction in Pediatric Patients With OCD Using Structural Neuroimaging Correlates: Simple Linear Regression Versus Support Vector Regression(2017) VATTIMO, Edoardo; BARROS, Vivian; BATISTUZZO, Marcelo; REQUENA, Guaraci; SATO, Joao; FATORI, Daniel; SHAVITT, Roseli; MIGUEL, Euripedes; HOEXTER, Marcelo- Differences in Default Mode Network Connectivity in Meditators and Non-meditators During an Attention Task(2017) KOZASA, Elisa H.; SATO, Joao R.; RUSSELL, Tamara A.; BARREIROS, Maria A. M.; LACERDA, Shirley S.; RADVANY, Joao; MELLO, Luiz E. A. M.; AMARO JR., EdsonActivity in the default mode network (DMN) is reduced during non-self-referential goal-directed tasks in healthy individuals. In this study, we investigated differences in DMN functional connectivity between regular meditators and non-meditators during an attention paradigm. Non-meditators and regular meditators, matched by age, years of education, and gender were instructed to name the color of single words visually presented in a Stroop Word-Color Task (SWCT) adapted for functional magnetic resonance imaging (fMRI). The task was performed when the participants were not formally meditating. Logistic analysis based on imaging data indicated that the connectivity between the PCC (precuneus/posterior cingulate cortex) and the right and left parietal lobules helps differentiating regular meditators from non-meditators. Granger causality results showed that the activity in the PCC contains information to predict the activity in the right lateral parietal cortex and that the accuracy in this prediction is higher in regular meditators when compared to non-meditators. This suggests a stronger link between these two regions in regular meditators. In contrast to regular meditators, the PCC is more influenced by the left parietal region (related to the process of reading-which is the interference in the SWCT), and this region is more influenced by the PCC in non-meditators. These functional connectivity differences in the DMN between groups possibly reflect a higher degree of interference and probably more distraction during the SWCT in non-meditators compared with meditators.
- Wavelet correlation between subjects: A time-scale data driven analysis for brain mapping using fMRI(2011) LESSA, Patricia S.; SATO, Joao R.; CARDOSO, Elisson F.; NETO, Carlos G.; VALADARES, Ana Paula; AMARO JR., EdsonFunctional magnetic resonance imaging (fMRI) based on BOLD signal has been used to indirectly measure the local neural activity induced by cognitive tasks or stimulation. Most fMRI data analysis is carried out using the general linear model (GLM), a statistical approach which predicts the changes in the observed BOLD response based on an expected hemodynamic response function (HRF). In cases when the task is cognitively complex or in cases of diseases, variations in shape and/or delay may reduce the reliability of results. A novel exploratory method using fMRI data, which attempts to discriminate between neurophysiological signals induced by the stimulation protocol from artifacts or other confounding factors, is introduced in this paper. This new method is based on the fusion between correlation analysis and the discrete wavelet transform, to identify similarities in the time course of the BOLD signal in a group of volunteers. We illustrate the usefulness of this approach by analyzing fMRI data from normal subjects presented with standardized human face pictures expressing different degrees of sadness. The results show that the proposed wavelet correlation analysis has greater statistical power than conventional GLM or time domain intersubject correlation analysis.
- Posterior-superior insular deep transcranial magnetic stimulation alleviates peripheral neuropathic pain - A pilot double-blind, randomized cross-over study(2021) DONGYANG, Liu; FERNANDES, Ana Mercia; CUNHA, Pedro Henrique Martins da; TIBES, Raissa; SATO, Joao; LISTIK, Clarice; DALE, Camila; KUBOTA, Gabriel Taricani; GALHARDONI, Ricardo; TEIXEIRA, Manoel Jacobsen; SILVA, Valquiria Aparecida da; ROSI, Jefferson; ANDRADE, Daniel Ciampi deObjectives. - Peripheral neuropathic pain (pNeP) is prevalent, and current treatments, including drugs and motor cortex repetitive transcranial magnetic stimulation (rTMS) leave a substantial proportion of patients with suboptimal pain relief. Methods. - We explored the intensity and short-term duration of the analgesic effects produced in pNeP patients by 5 days of neuronavigated deep rTMS targeting the posterior superior insula (PSI) with a double-cone coil in a sham-controlled randomized cross-over trial. Results. - Thirty-one pNeP patients received induction series of five active or sham consecutive sessions of daily deep-rTMS to the PSI in a randomized sequence, with a washout period of at least 21 days between series. The primary outcome [number of responders (>50% pain intensity reduction from baseline in a numerical rating scale ranging from 0 to 10)] was significantly higher after real (58.1%) compared to sham (19.4%) stimulation (p = 0.002). The number needed to treat was 2.6, and the effect size was 0.97 [95% CI (0.6; 1.3)]. One week after the 5th stimulation day, pain scores were no longer different between groups, and no difference in neuropathic pain characteristics and interference with daily living were present. No major side effects occurred, and milder adverse events (i.e., short-lived headaches after stimulation) were reported in both groups. Blinding was effective, and analgesic effects were not affected by sequence of the stimulation series (active-first or sham-first), age, sex or pain duration of participants. Discussion. - PSI deep-rTMS was safe in refractory pNeP and was able to provide significant pain intensity reduction after a five-day induction series of treatments. Post-hoc assessment of neuronavigation targeting confirmed deep-rTMS was delivered within the boundaries of the PSI in all participants. Conclusion. - PSI deep-rTMS provided significant pain relief during 5-day induction sessions compared to sham stimulation.
- Temporal Stability of Network Centrality in Control and Default Mode Networks: Specific Associations with Externalizing Psychopathology in Children and Adolescents(2015) SATO, Joao Ricardo; BIAZOLI JR., Claudinei Eduardo; SALUM, Giovanni Abrahao; GADELHA, Ary; CROSSLEY, Nicolas; SATTERTHWAITE, Theodore D.; VIEIRA, Gilson; ZUGMAN, Andre; PICON, Felipe Almeida; PAN, Pedro Mario; HOEXTER, Marcelo Queiroz; ANES, Mauricio; MOURA, Luciana Monteiro; DEL'AQUILLA, Marco Antonio Gomes; AMARO JR., Edson; MCGUIRE, Philip; LACERDA, Acioly L. T.; ROHDE, Luis Augusto; MIGUEL, Euripedes Constantino; JACKOWSKI, Andrea Parolin; BRESSAN, Rodrigo AffonsecaAbnormal connectivity patterns have frequently been reported as involved in pathological mental states. However, most studies focus on ""static,"" stationary patterns of connectivity, which may miss crucial biological information. Recent methodological advances have allowed the investigation of dynamic functional connectivity patterns that describe non-stationary properties of brain networks. Here, we introduce a novel graphical measure of dynamic connectivity, called time-varying eigenvector centrality (tv-EVC). In a sample 655 children and adolescents (7-15 years old) from the Brazilian ""High Risk Cohort Study for Psychiatric Disorders"" who were imaged using resting-state fMRI, we used this measure to investigate age effects in the temporal in control and default-mode networks (CN/DMN). Using support vector regression, we propose a network maturation index based on the temporal stability of tv-EVC. Moreover, we investigated whether the network maturation is associated with the overall presence of behavioral and emotional problems with the Child Behavior Checklist. As hypothesized, we found that the tv-EVC at each node of CN/DMN become more stable with increasing age (P < 0.001 for all nodes). In addition, the maturity index for this particular network is indeed associated with general psychopathology in children assessed by the total score of Child Behavior Checklist (P = 0.027). Moreover, immaturity of the network was mainly correlated with externalizing behavior dimensions. Taken together, these results suggest that changes in functional network dynamics during neurodevelopment may provide unique insights regarding pathophysiology. (C) 2015 Wiley Periodicals, Inc.
- Meditation training increases brain efficiency in an attention task(2012) KOZASA, Elisa H.; SATO, Joao R.; LACERDA, Shirley S.; BARREIROS, Maria A. M.; RADVANY, Joao; RUSSELL, Tamara A.; SANCHES, Liana G.; MELLO, Luiz E. A. M.; AMARO JR., EdsonMeditation is a mental training, which involves attention and the ability to maintain focus on a particular object. In this study we have applied a specific attentional task to simply measure the performance of the participants with different levels of meditation experience, rather than evaluating meditation practice per se or task performance during meditation. Our objective was to evaluate the performance of regular meditators and non-meditators during an fMRI adapted Stroop Word-Colour Task (SWCT), which requires attention and impulse control, using a block design paradigm. We selected 20 right-handed regular meditators and 19 non-meditators matched for age, years of education and gender. Participants had to choose the colour (red, blue or green) of single words presented visually in three conditions: congruent, neutral and incongruent. Non-meditators showed greater activity than meditators in the right medial frontal, middle temporal, precentral and postcentral gyri and the lentiform nucleus during the incongruent conditions. No regions were more activated in meditators relative to non-meditators in the same comparison. Non-meditators showed an increased pattern of brain activation relative to regular meditators under the same behavioural performance level. This suggests that meditation training improves efficiency, possibly via improved sustained attention and impulse control.
- Decreased centrality of subcortical regions during the transition to adolescence: A functional connectivity study(2015) SATO, Joao Ricardo; SALUM, Giovanni Abrahao; GADELHA, Ary; VIEIRA, Gilson; ZUGMAN, Andre; PICON, Felipe Almeida; PAN, Pedro Mario; HOEXTER, Marcelo Queiroz; ANES, Mauricio; MOURA, Luciana Monteiro; DEL'AQUILLA, Marco Antonio Gomes; CROSSLEY, Nicolas; AMARO JUNIOR, Edson; MCGUIRE, Philip; LACERDA, Acioly L. T.; ROHDE, Luis Augusto; MIGUEL, Euripedes Constantino; JACKOWSKI, Andrea Parolin; BRESSAN, Rodrigo AffonsecaInvestigations of brain maturation processes are a key step to understand the cognitive and emotional changes of adolescence. Although structural imaging findings have delineated clear brain developmental trajectories for typically developing individuals, less is known about the functional changes of this sensitive development period. Developmental changes, such as abstract thought, complex reasoning, and emotional and inhibitory control, have been associated with more prominent cortical control. The aim of this study is to assess brain networks connectivity changes in a large sample of 7- to 15-year-old subjects, testing the hypothesis that cortical regions will present an increasing relevance in commanding the global network. Functional magnetic resonance imaging (fMRI) data were collected in a sample of 447 typically developing children from a Brazilian community sample who were submitted to a resting state acquisition protocol. The fMRI data were used to build a functional weighted graph from which eigenvector centrality (EVC) was extracted. For each brain region (a node of the graph), the age-dependent effect on EVC was statistically tested and the developmental trajectories were estimated using polynomial functions. Our findings show that angular gyrus become more central during this maturation period, while the caudate; cerebellar tonsils, pyramis, thalamus; fusiform, parahippocampal and inferior semilunar lobe become less central. In conclusion, we report a novel finding of an increasing centrality of the angular gyrus during the transition to adolescence, with a decreasing centrality of many subcortical and cerebellar regions.
- Identification of psychopathic individuals using pattern classification of MRI images(2011) SATO, Joao R.; OLIVEIRA-SOUZA, Ricardo de; THOMAZ, Carlos E.; BASILIO, Rodrigo; BRAMATI, Ivanei E.; AMARO JR., Edson; TOVAR-MOLL, Fernanda; HARE, Robert D.; MOLL, JorgeBackground: Psychopathy is a disorder of personality characterized by severe impairments of social conduct, emotional experience, and interpersonal behavior. Psychopaths consistently violate social norms and bring considerable financial, emotional, or physical harm to others and to society as a whole. Recent developments in analysis methods of magnetic resonance imaging (MRI), such as voxel-based-morphometry (VBM), have become major tools to understand the anatomical correlates of this disorder. Nevertheless, the identification of psychopathy by neuroimaging or other neurobiological tools (e. g., genetic testing) remains elusive. Methods/Principal findings: The main aim of this study was to develop an approach to distinguish psychopaths from healthy controls, based on the integration between pattern recognition methods and gray matter quantification. We employed support vector machines (SVM) and maximum uncertainty linear discrimination analysis (MLDA), with a feature-selection algorithm. Imaging data from 15 healthy controls and 15 psychopathic individuals (7 women in each group) were analyzed with SPM2 and the optimized VBM preprocessing routines. Participants were scanned with a 1.5 Tesla MRI system. Both SVM and MLDA achieved an overall leave-one-out accuracy of 80%, but SVM mapping was sparser than using MLDA. The superior temporal sulcus/gyrus (bilaterally) was identified as a region containing the most relevant information to separate the two groups. Conclusion/significance: These results indicate that gray matter quantitative measures contain robust information to predict high psychopathy scores in individual subjects. The methods employed herein might prove useful as an adjunct to the established clinical and neuropsychological measures in patient screening and diagnostic accuracy.
- Multimodal imaging of mild traumatic brain injury and persistent postconcussion syndrome(2015) DEAN, Philip J. A.; SATO, Joao R.; VIEIRA, Gilson; MCNAMARA, Adam; STERR, AnnetteBackground: Persistent postconcussion syndrome (PCS) occurs in around 5-10% of individuals after mild traumatic brain injury (mTBI), but research into the underlying biology of these ongoing symptoms is limited and inconsistent. One reason for this could be the heterogeneity inherent to mTBI, with individualized injury mechanisms and psychological factors. A multimodal imaging study may be able to characterize the injury better. Aim: To look at the relationship between functional (fMRI), structural (diffusion tensor imaging), and metabolic (magnetic resonance spectroscopy) data in the same participants in the long term (>1year) after injury. It was hypothesized that only those mTBI participants with persistent PCS would show functional changes, and that these changes would be related to reduced structural integrity and altered metabolite concentrations. Methods: Functional changes associated with persistent PCS after mTBI (>1year postinjury) were investigated in participants with and without PCS (both n=8) and non-head injured participants (n=9) during performance of working memory and attention/processing speed tasks. Correlation analyses were performed to look at the relationship between the functional data and structural and metabolic alterations in the same participants. Results: There were no behavioral differences between the groups, but participants with greater PCS symptoms exhibited greater activation in attention-related areas (anterior cingulate), along with reduced activation in temporal, default mode network, and working memory areas (left prefrontal) as cognitive load was increased from the easiest to the most difficult task. Functional changes in these areas correlated with reduced structural integrity in corpus callosum and anterior white matter, and reduced creatine concentration in right dorsolateral prefrontal cortex. Conclusion: These data suggest that the top-down attentional regulation and deactivation of task-irrelevant areas may be compensating for the reduction in working memory capacity and variation in white matter transmission caused by the structural and metabolic changes after injury. This may in turn be contributing to secondary PCS symptoms such as fatigue and headache. Further research is required using multimodal data to investigate the mechanisms of injury after mTBI, but also to aid individualized diagnosis and prognosis.