EDSON AMARO JUNIOR
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Radiologia, Faculdade de Medicina - Docente
LIM/44 - Laboratório de Ressonância Magnética em Neurorradiologia, Hospital das Clínicas, Faculdade de Medicina
LIM/44 - Laboratório de Ressonância Magnética em Neurorradiologia, Hospital das Clínicas, Faculdade de Medicina
17 resultados
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- Brain atrophy in primary progressive aphasia involves the cholinergic basal forebrain and Ayala's nucleus(2014) TEIPEL, Stefan J.; FLATZ, Wilhelm; ACKL, Nibal; GROTHE, Michel; KILIMANN, Ingo; BOKDE, Arun L. W.; GRINBERG, Lea; AMARO JR., Edson; KLJAJEVIC, Vanja; ALHO, Eduardo; KNELS, Christina; EBERT, Anne; HEINSEN, Helmut; DANEK, AdrianPrimary progressive aphasia (PPA) is characterized by left hemispheric frontotemporal cortical atrophy. Evidence from anatomical studies suggests that the nucleus subputaminalis (NSP), a subnucleus of the cholinergic basal forebrain, may be involved in the pathological process of PPA. Therefore, we studied the pattern of cortical and basal forebrain atrophy in 10 patients with a clinical diagnosis of PPA and 18 healthy age matched controls using high resolution magnetic resonance imaging (MRI). We determined the cholinergic basal forebrain nuclei according to Mesulam's nomenclature and the NSP in MRI reference space based on histological sections and the MRI scan of a post-mortem brain in cranio. Using voxel-based analysis, we found left hemispheric cortical atrophy in PPA patients compared with controls, including prefrontal, lateral temporal and medial temporal lobe areas. We detected cholinergic basal forebrain atrophy in left predominant localizations of Ch4p, Ch4am, Ch4al, Ch3 and NSP. For the first time, we have described the pattern of basal forebrain atrophy in PPA and confirmed the involvement of NSP that had been predicted based on theoretical considerations. Our findings may enhance understanding of the role of cholinergic degeneration for the regional specificity of the cortical destruction leading to the syndrome of PPA.
- p Deep learning for Alzheimer's disease: Mapping large-scale histological tau protein for neuroimaging biomarker validation(2022) USHIZIMA, Daniela; CHEN, Yuheng; ALEGRO, Maryana; OVANDO, Dulce; ESER, Rana; LEE, WingHung; POON, Kinson; SHANKAR, Anubhav; KANTAMNENI, Namrata; SATRAWADA, Shruti; AMARO JUNIOR, Edson; HEINSEN, Helmut; TOSUN, Duygu; GRINBERG, Lea T.Abnormal tau inclusions are hallmarks of Alzheimer's disease and predictors of clinical decline. Several tau PET tracers are available for neurodegenerative disease research, opening avenues for molecular diagnosis in vivo. However, few have been approved for clinical use. Understanding the neurobiological basis of PET signal validation remains problematic because it requires a large-scale, voxel-to-voxel correlation between PET and (immuno) histological signals. Large dimensionality of whole human brains, tissue deformation impacting co-registration, and computing requirements to process terabytes of information preclude proper validation. We developed a computational pipeline to identify and segment particles of interest in billion-pixel digital pathology images to generate quantitative, 3D density maps. The proposed convolutional neural network for immunohistochemistry samples, IHCNet, is at the pipeline's core. We have successfully processed and immunostained over 500 slides from two whole human brains with three phospho-tau antibodies (AT100, AT8, and MC1), spanning several terabytes of images. Our artificial neural network estimated tau inclusion from brain images, which performs with ROC AUC of 0.87, 0.85, and 0.91 for AT100, AT8, and MC1, respectively. Introspection studies further assessed the ability of our trained model to learn tau-related features. We present an end-to-end pipeline to create terabytes-large 3D tau inclusion density maps co-registered to MRI as a means to facilitate validation of PET tracers.
- The role of artificial intelligence and machine learning in harmonization of high-resolution post-mortem MRI (virtopsy) with respect to brain microstructure(2019) O’SULLIVAN, S.; HEINSEN, H.; GRINBERG, L.T.; CHIMELLI, L.; AMARO, E. Jr.; SALDIVA, P.H. do Nascimento; JEANQUARTIER, F.; JEAN-QUARTIER, C.; MARTIN, M. da Graça Morais; SAJID, M.I.; HOLZINGER, A.Enhanced resolution of 7 T magnetic resonance imaging (MRI) scanners has considerably advanced our knowledge of structure and function in human and animal brains. Post-industrialized countries are particularly prone to an ever-increasing number of ageing individuals and ageing-associated neurodegenerative diseases. Neurodegenerative diseases are associated with volume loss in the affected brain. MRI diagnoses and monitoring of subtle volume changes in the ageing/diseased brains have the potential to become standard diagnostic tools. Even with the superior resolution of 7 T MRI scanners, the microstructural changes comprising cell types, cell numbers, and cellular processes, are still undetectable. Knowledge of origin, nature, and progression for microstructural changes are necessary to understand pathogenetic stages in the relentless neurodegenerative diseases, as well as to develop therapeutic tools that delay or stop neurodegenerative processes at their earliest stage. We illustrate the gap in resolution by comparing the identical regions of the post-mortem in situ 7 T MR images (virtual autopsy or virtopsy) with the histological observations in serial sections through the same brain. We also described the protocols and limitations associated with these comparisons, as well as the necessity of supercomputers and data management for “Big data”. Analysis of neuron and/or glial number by using a body of mathematical tools and guidelines (stereology) is time-consuming, cumbersome, and still restricted to trained human investigators. Development of tools based on machine learning (ML) and artificial intelligence (AI) could considerably accelerate studies on localization, onset, and progression of neuron loss. Finally, these observations could disentangle the mechanisms of volume loss into stages of reversible atrophy and/or irreversible fatal cell death. This AI- and ML-based cooperation between virtopsy and histology could bridge the present gap between virtual reality and neuropathology. It could also culminate in the creation of an imaging-associated comprehensive database. This database would include genetic, clinical, epidemiological, and technical aspects that could help to alleviate or even stop the adverse effects of neurodegenerative diseases on affected individuals, their families, and society. © 2019, The Author(s).
- Associations between children's family environment, spontaneous brain oscillations, and emotional and behavioral problems(2019) SATO, Joao Ricardo; JR, Claudinei Eduardo Biazoli; SALUM, Giovanni Abrahao; GADELHA, Ary; CROSSLEY, Nicolas; VIEIRA, Gilson; ZUGMAN, Andre; PICON, Felipe Almeida; PAN, Pedro Mario; HOEXTER, Marcelo Queiroz; JR, Edson Amaro; ANES, Mauricio; MOURA, Luciana Monteiro; DEL'AQUILLA, Marco Antonio Gomes; MCGUIRE, Philip; ROHDEZ, Luis Augusto; MIGUEL, Euripedes Constantino; BRESSAN, Rodrigo Affonseca; JACKOWSKI, Andrea ParolinThe family environment in childhood has a strong effect on mental health outcomes throughout life. This effect is thought to depend at least in part on modifications of neurodevelopment trajectories. In this exploratory study, we sought to investigate whether a feasible resting-state fMRI metric of local spontaneous oscillatory neural activity, the fractional amplitude of low-frequency fluctuations (fALFF), is associated with the levels of children's family coherence and conflict. Moreover, we sought to further explore whether spontaneous activity in the brain areas influenced by family environment would also be associated with a mental health outcome, namely the incidence of behavioral and emotional problems. Resting-state fMRI data from 655 children and adolescents (6-15years old) were examined. The quality of the family environment was found to be positively correlated with fALFF in the left temporal pole and negatively correlated with fALFF in the right orbitofrontal cortex. Remarkably, increased fALFF in the temporal pole was associated with a lower incidence of behavioral and emotional problems, whereas increased fALFF in the orbitofrontal cortex was correlated with a higher incidence.
- 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.
- Brain injury after moderate drowning: subtle alterations detected by functional magnetic resonance imaging(2017) NUCCI, Mariana P.; LUKASOVA, Katerina; SATO, Joo R.; AMARO JR., EdsonTo describe cerebral (structural and functional MRI) and neuropsychological long term changes in moderate drowning victim's compared to healthy volunteers in working memory and motor domains. We studied 15 adult drowning victim's in chronic stage (DV - out of 157 eligible cases of sea water rescues with moderate drowning classification) paired to 18 healthy controls (HC). All participants were investigated using intelligence, memory, and attention neuropsychological standard tests and underwent functional (motor and working memory tasks) and structural magnetic resonance imaging (MRI) in a 3 T system. All images were preprocessed for head movement correction and quantitative analysis was performed using FSL and freesurfer software packages. We found no between group differences in neuropsychological assessments. No MRI brain lesion was observed in patients, neither difference on morphometric parameters in any cortical or subcortical brain structure. In constrast, functional MRI revealed that patients showed increased brain response in the motor (left putamen and insula) and memory (left cuneus and lingual gyrus - not the classical memory network) tasks. Functional brain changes in motor and visual brain regions in victims of moderate drowning may indicate reduced brain reserve, despite the lack of structural and behavior alterations. More attention should be given to investigate ageing effects in this nonfatal drowning group.
- Developmental trajectory of the prefrontal cortex: a systematic review of diffusion tensor imaging studies(2018) SOUSA, Sonia S.; AMARO JR., Edson; CREGO, Alberto; GONCALVES, Oscar F.; SAMPAIO, AdrianaFluctuations in gray and white matter volumes in addition to the fibers' reorganization and refinement of synaptic connectivity apparently happen in a particular temporo-spatial sequence during the dynamic and prolonged process of cerebral maturation. These developmental events are associated with regional modifications of brain tissues and neural circuits, contributing to networks' specialization and enhanced cognitive processing. According to several studies, improvements in cognitive processes are possibly myelin-dependent and associated to white matter maturation. Of particular interest is the developmental pattern of the prefrontal cortex (PFC), more specifically the PFC white matter, due to its role in high-level executive processes such as attention, working memory and inhibitory control. A systematic review of the literature was conducted using the Web of Science, PubMed and Embase databases to analyze the development of PFC white matter using Diffusion Tensor Imaging (DTI), a widely used non-invasive technique to assess white matter maturation. Both the research and reporting of results were based on Cochrane's recommendations and PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analysis) guidelines. Information extracted from 27 published studies revealed an increased myelination, organization and integrity of frontal white matter with age, as revealed by DTI indexes (fractional anisotropy [FA], mean diffusivity [MD], radial diffusivity [RD] and axial diffusivity [AD]). These patterns highlight the extended developmental course of the frontal structural connectivity, which parallels the improvements in higher-level cognitive functions observed between adolescence and early adulthood.
- Subthalamic nucleus deep brain stimulation: Basic concepts and novel perspectives(2017) HAMANI, C.; FLORENCE, G.; HEINSEN, H.; PLANTINGA, B. R.; TEMEL, Y.; ULUDAG, K.; ALHO, E.; TEIXEIRA, M. J.; AMARO, E.; FONOFF, E. T.Over the last decades, extensive basic and clinical knowledge has been acquired on the use of subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson’s disease (PD). It is now clear that mechanisms involved in the effects of this therapy are far more complex than previously anticipated. At frequencies commonly used in clinical practice, neural elements may be excited or inhibited and novel dynamic states of equilibrium are reached. Electrode contacts used for chronic DBS in PD are placed near the dorsal border of the nucleus, a highly cellular region. DBS may thus exert its effects by modulating these cells, hyperdirect projections from motor cortical areas, afferent and efferent fibers to the motor STN. Advancements in neuroimaging techniques may allow us to identify these structures optimizing surgical targeting. In this review, we provide an update on mechanisms and the neural elements modulated by STN DBS. © 2017 Hamani et al.
- 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.