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
19 resultados
Resultados de Busca
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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.
- Cholinergic basal forebrain atrophy predicts amyloid burden in Alzheimer's disease(2014) TEIPEL, Stefan; HEINSEN, Helmut; AMARO JR., Edson; GRINBERG, Lea T.; KRAUSE, Bernd; GROTHE, MichelWe compared accuracy of hippocampus and basal forebrain cholinergic system (BFCS) atrophy to predict cortical amyloid burden in 179 cognitively normal subjects (CN), 269 subjects with early stages of mild cognitive impairment (MCI), 136 subjects with late stages of MCI, and 86 subjects with Alzheimer's disease (AD) dementia retrieved from the Alzheimer's Disease Neuroimaging Initiative database. Hippocampus and BFCS volumes were determined from structural magnetic resonance imaging scans at 3 Tesla, and cortical amyloid load from AV45 (florbetapir) positron emission tomography scans. In receiver operating characteristics analyses, BFCS volume provided significantly more accurate classification into amyloid-negative and -positive categories than hippocampus volume. In contrast, hippocampus volume more accurately identified the diagnostic categories of AD, late and early MCI, and CN compared with whole and anterior BFCS volume, whereas posterior BFCS and hippocampus volumes yielded similar diagnostic accuracy. In logistic regression analysis, hippocampus and posterior BFCS volumes contributed significantly to discriminate MCI and AD from CN, but only BFCS volume predicted amyloid status. Our findings suggest that BFCS atrophy is more closely associated with cortical amyloid burden than hippocampus atrophy in predementia AD.
- Differences between postmortem computed tomography and conventional autopsy in a stabbing murder case(2014) ZERBINI, Talita; SILVA, Luiz Fernando Ferraz da; FERRO, Antonio Carlos Goncalves; KAY, Fernando Uliana; AMARO JUNIOR, Edson; PASQUALUCCI, Carlos Augusto Goncalves; SALDIVA, Paulo Hilario do NascimentoOBJECTIVE: The aim of the present work is to analyze the differences and similarities between the elements of a conventional autopsy and images obtained from postmortem computed tomography in a case of a homicide stab wound. METHOD: Comparison between the findings of different methods: autopsy and postmortem computed tomography. RESULTS: In some aspects, autopsy is still superior to imaging, especially in relation to external examination and the description of lesion vitality. However, the findings of gas embolism, pneumothorax and pulmonary emphysema and the relationship between the internal path of the instrument of aggression and the entry wound are better demonstrated by postmortem computed tomography. CONCLUSIONS: Although multislice computed tomography has greater accuracy than autopsy, we believe that the conventional autopsy method is fundamental for providing evidence in criminal investigations.
- Brain network dynamics characterization in epileptic seizures(2014) RODRIGUES, A. C.; MACHADO, B. S.; FLORENCE, G.; HAMAD, A. P.; SAKAMOTO, A. C.; FUJITA, A.; BACCALA, L. A.; AMARO JR., E.; SAMESHIMA, K.Here we propose and evaluate a new approach to analyse multichannel mesial temporal lobe epilepsy EEG data from eight patients through complex network and synchronization theories. The method employs a Granger causality test to infer the directed connectivity graphs and a wavelet transform based phase synchronization measure whose characteristics allow studying dynamical transitions during epileptic seizures. We present a new combined graph measure that quantifies the level of network hub formation, called network hub out-degree, which closely reflects the level of synchronization observed during the ictus.
- The Relationship Between Childhood Behavior and Cortical Thickness in Scholars From 7-14 Years Old(2014) ZUGMAN, Andre; SATO, Joao; AQUILLA, Marco Dell; PAN, Pedro M.; GADELHA, Ary; KEMPTON, Matthew; MORIYAMA, Tais; HOEXTER, Marcelo; SALLUM, Giovanni A.; ROSARIO, Maria C.; POLANCZYK, Guilherme; ALVARENGA, Pedro; PICON, Felipe A.; AMARO, Edson; MIGUEL, Euripedes C.; ROHDE, Luis A.; MCGUIRE, Philip; MARI, Jair J.; BRESSAN, Rodrigo A.; JACKOWSKI, Andrea P.
- Brain regions supporting verbal memory improvement in healthy older subjects(2014) MIOTTO, Eliane C.; BALARDIN, Joana B.; SAVAGE, Cary R.; MARTIN, Maria da Graca M.; BATISTUZZO, Marcelo C.; AMARO JUNIOR, Edson; NITRINI, RicardoDespite growing interest in developing cognitive training interventions to minimize the aging cognitive decline process, no studies have attempted to explore which brain regions support the application of semantic strategies during verbal memory encoding. Our aim was to investigate the behavioral performance and brain correlates of these strategies in elderly individuals using fMRI in healthy older subjects. Method: Subjects were scanned twice on the same day, before and after, directed instructions to apply semantic strategies during the encoding of word lists. Results: Improved memory performance associated to increased semantic strategy application and brain activity in the left inferior and middle and right medial superior prefrontal cortex were found after the directed instructions. There was also reduced activation in areas related to strategy mobilization. Conclusion: Improved memory performance in older subjects after the application of semantic strategies was associated with functional brain reorganization involving regions inside and outside the typical memory network.
conferenceObject AGE-RELATED CHANGES IN THE POSTERIOR CINGULATE CORTEX FUNCTIONAL CONNECTIVITY: A RESTING-STATE FMRI STUDY IN ADULTS FREE OF NEUROPSYCHIATRIC DISORDERS(2014) FERREIRA, L. K.; REGINA, A. C. B.; KOVACEVIC, N.; CARNEIRO, C. G.; MARTIN, M. G. M.; AMARO JR., E.; MCINTOSH, A. R.; BUSATTO, G. F.- Executive function and depressive symptoms of retardation in nonelderly stroke patients(2014) SOBREIRO, Matildes F. M.; MIOTTO, Eliane Correa; TERRONI, Luisa; TINONE, Gisela; IOSIFESCU, Dan V.; LUCIA, Mara C. S. de; SCAFF, Milberto; LEITE, Claudia da Costa; AMARO JR., Edson; FRAGUAS, RenerioThe depression-executive dysfunction syndrome, a late-onset depression of vascular origin with executive dysfunction and psychomotor retardation, has also been described after stroke. We verified whether this syndrome also occurs in nonelderly stroke patients by investigating the association between domains of depressive symptoms with executive functions in 87 first-ever ischemic stroke patients. The retardation domain of the 31-item Hamilton Rating Scale for Depression was associated with decreased performance on verbal fluency (assessed with FAS). The association was maintained for younger patients (aged <60 years) after adjusting for confounders. This result supports the clinical presentation of depression-executive dysfunction syndrome in younger stroke patients. Confirmation of this finding, its neural correlates, and clinical implication deserve further investigation.
- Randomized, proof-of-principle clinical trial of active transcranial magnetic stimulation in chronic migraine(2014) CONFORTO, Adriana B.; AMARO JR., Edson; GONCALVES, Andre L.; MERCANTE, Juliane P. P.; GUENDLER, Vera Z.; FERREIRA, Josione R.; KIRSCHNER, Clara C. F. B.; PERES, Mario F. P.Background High-frequency repetitive transcranial magnetic stimulation of the left dorsolateral prefrontal cortex (rTMS-DLPFC) is an effective treatment for depression. Preliminary studies indicated beneficial effects of rTMS-DLPFC on pain relief in patients treated for depression, and in patients with chronic migraine. Methods In this randomized, double-blind, parallel-group, single-center, proof-of-principle clinical trial, we tested the hypothesis that 23 sessions of active rTMS-DLPFC delivered over eight weeks would be feasible, safe and superior to sham rTMS to decrease the number of headache days in 18 patients with chronic migraine without severe depression. Per-protocol analysis was performed. Results rTMS-DLPFC applied over eight weeks was feasible and safe in patients with chronic migraine. Contrary to our primary hypothesis, the number of headache days decreased significantly more in the sham group than in the group treated with active rTMS-DLPFC at eight weeks. Average decrease in headache days was >50% in the sham group, indicating a powerful placebo response. Pain intensity improved in both groups to a similar extent. Conclusions Positive results of M1 stimulation in other studies, and the absence of significant benefits of active high-frequency rTMS of the DLPFC in the present study, point to M1 as a more promising target than the DLPFC, for larger trials of noninvasive brain stimulation in patients with chronic migraine.
- LOCAL SPARSE COMPONENT ANALYSIS FOR BLIND SOURCE SEPARATION: AN APPLICATION TO RESTING STATE FMRI(2014) VIEIRA, Gilson; AMARO JR., Edson; BACCALA, Luiz A.We propose a new Blind Source Separation technique for whole-brain activity estimation that best profits from FMRI's intrinsic spatial sparsity. The Local Sparse Component Analysis (LSCA) combines wavelet analysis, group-separable regularizers, contiguity-constrained clusterization and principal components analysis (PCA) into a unique spatial sparse representation of FMRI images towards efficient dimensionality reduction without sacrificing physiological characteristics by avoiding artificial stochastic model constraints. The LSCA outperforms classical PCA source reconstruction for artificial data sets over many noise levels. A real FMRI data illustration reveals resting-state activities in regions hard to observe, such as thalamus and basal ganglia, because of their small spatial scale.