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
148 resultados
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- Seeking tools for image fusion between computed tomography, structural and functional magnetic resonance methods for applications in neurosurgery(2012) ROCHA, Liana Guerra Sanches da; AMARO JUNIOR, EdsonOBJECTIVE: To evaluate tools for the fusion of images generated by tomography and structural and functional magnetic resonance imaging. METHODS: Magnetic resonance and functional magnetic resonance imaging were performed while a volunteer who had previously undergone cranial tomography performed motor and somatosensory tasks in a 3-Tesla scanner. Image data were analyzed with different programs, and the results were compared. RESULTS: We constructed a flow chart of computational processes that allowed measurement of the spatial congruence between the methods. There was no single computational tool that contained the entire set of functions necessary to achieve the goal. CONCLUSION: The fusion of the images from the three methods proved to be feasible with the use of four free-access software programs (OsiriX, Register, MRIcro and FSL). Our results may serve as a basis for building software that will be useful as a virtual tool prior to neurosurgery.
- Rapid hippocampal plasticity supports motor sequence learning(2020) JACOBACCI, Florencia; ARMONY, Jorge L.; YEFFAL, Abraham; LERNER, Gonzalo; JR, Edson Amaro; JOVICICH, Jorge; DOYON, Julien; DELLA-MAGGIORE, ValeriaRecent evidence suggests that gains in performance observed while humans learn a novel motor sequence occur during the quiet rest periods interleaved with practice (micro-offline gains, MOGs). This phenomenon is reminiscent of memory replay observed in the hippocampus during spatial learning in rodents. Whether the hippocampus is also involved in the production of MOGs remains currently unknown. Using a multimodal approach in humans, here we show that activity in the hippocampus and the precuneus increases during the quiet rest periods and predicts the level of MOGs before asymptotic performance is achieved. These functional changes were followed by rapid alterations in brain microstructure in the order of minutes, suggesting that the same network that reactivates during the quiet periods of training undergoes structural plasticity. Our work points to the involvement of the hippocampal system in the reactivation of procedural memories.
- 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.
- Analysis of fractional anisotropy and mean diffusivity in refractory and non-refractory idiopathic generalized epilepsies(2018) LOBATO, Mauricio; GARCIA, Lucas; AMARO JR., Edson; OTADUY, Maria; JORGE, Carmen; CASTRO, Luiz H.Purpose: To compare white matter bundles and fiber tract changes in seizure-free and non-seizure-free idiopathic generalized epilepsy (IGE) patients. Method: Forty adult patients with IGE underwent a 3 T brain MRI with DTI sequences. According to seizure control status, eighteen patients were classified as refractory (R) if they had presented at least one incapacitating seizure in the previous six months, while on appropriate antiepileptic drug treatment. Twenty two seizure-free patients with adequate seizure control were considered non-refractory (NR). We compared fractional anisotropy (FA) and mean diffusivity (MD) values in sixteen white matter tracts in the R and NR groups, and in twenty healthy subjects. Results: R and NR groups did not differ in gender, age and education. We found decreased FA in two tracts in the R group (forceps major and right uncinate fasciculus) and approaching statistical significance in two tracts in the NR group (right cingulate gyrus and right uncinate fasciculus) group, as well as increased MD in six tracts in the R group (forceps minor, left thalamic anterior radiation, right inferior longitudinal fasciculus, right longitudinal superior parietal and temporal fasciculi, and right cingulate gyrus) and in five tracts in the NR group (forceps minor, left thalamic anterior radiation, right inferior longitudinal fasciculus, right longitudinal superior parietal and temporal fasciculi), compared to controls. No differences were noted comparing FA and MD values between R and NR groups. Conclusions: In our patient population, refractory IGE patients on adequate antiepileptic drug treatment did not present more severe white matter tract involvement compared to non-refractory patients.
- Nationwide Cross-Sectional Epidemiological Analysis of 3,306 Lower Limb Peripheral Aneurysm Repairs in Brazilian Public Hospitals Between 2008 and 2019: Trends, Mortality and Costs(2022) SILVA, Marcelo Fiorelli Alexandrino da; LOUZADA, Andressa Cristina Sposato; TEIVELIS, Marcelo Passos; AMARO JUNIOR, Edson; WOLOSKER, NelsonBackground: Although peripheral aneurysms can be limb- or life-threatening, the literature is scarce and there are only two large population-based epidemiological studies on peripheral aneurysm repair, comprising data from high-income countries only. Methods: This is a retrospective cross-sectional analysis on open and endovascular peripheral aneurysm repairs performed between 2008 and 2019 in the Brazilian Public Health System, which exclusively insures more than 160 million Brazilians. Results: A total of 3,306 peripheral aneurysm repairs were observed. Most patients were elderly (57.74%) and male (72.66%), and patients treated with endovascular repair were older (P = 0.008). Most repairs were emergency (59.56%) and open (93.8%), and there was an overall downward trend in procedure rates. We observed a decreasing predominance of emergency open repair over elective open repair (P < 0.001), but open repairs prevailed over endovascular procedures, with no tendency to change this predominance. Mortality rates were 3.12% and 3.67% after elective and emergency open repair, respectively, with no difference, and 0 and 4.24% for elective and emergency endovascular repair, respectively. The government reimbursed an average of $1170.05 for open PA repair and $1802.01 for endovascular repair. Conclusions: We presented the largest series of the literature analyzing all 3,306 lower limb peripheral aneurysm repairs performed in public hospitals in a middle-income country. Procedure rates tended to decrease. Open repair predominated. Mortality rates ranged from 0 to 4%. Most procedures were emergency, but there was a relative increase of elective treatments over the years.
- Predictive saccades in children and adults: A combined fMRI and eye tracking study(2018) LUKASOVA, Katerina; NUCCI, Mariana P.; AZEVEDO NETO, Raymundo Machado de; VIEIRA, Gilson; SATO, Joao R.; JR, Edson AmaroSaccades were assessed in 21 adults (age 24 years, SD = 4) and 15 children (age 11 years, SD = 1), using combined functional magnetic resonance imaging (fMRI) and eye-tracking. Subjects visually tracked a point on a horizontal line in four conditions: time and position predictable task (PRED), position predictable (pPRED), time predictable (tPRED) and visually guided saccades (SAC). Both groups in the PRED but not in pPRED, tPRED and SAC produced predictive saccades with latency below 80 ms. In task versus group comparisons, children's showed less efficient learning compared to adults for predictive saccades (adults = 48%, children = 34%, p = 0.05). In adults brain activation was found in the frontal and occipital regions in the PRED, in the intraparietal sulcus in pPRED and in the frontal eye field, posterior intraparietal sulcus and medial regions in the tPRED task. Group-task interaction was found in the supplementary eye field and visual cortex in the PRED task, and the frontal cortex including the right frontal eye field and left frontal pole, in the pPRED condition. These results indicate that, the basic visuomotor circuitry is present in both adults and children, but fine-tuning of the activation according to the task temporal and spatial demand mature late in child development.
- Age-related gray matter volume changes in the brain during non-elderly adulthood(2011) TERRIBILLI, Debora; SCHAUFELBERGER, Maristela S.; DURAN, Fabio L. S.; ZANETTI, Marcus V.; CURIATI, Pedro K.; MENEZES, Paulo R.; SCAZUFCA, Marcia; AMARO JR., Edson; LEITE, Claudia C.; BUSATTO, Geraldo F.Previous magnetic resonance imaging (MRI) studies described consistent age-related gray matter (GM) reductions in the fronto-parietal neocortex, insula and cerebellum in elderly subjects, but not as frequently in limbic/paralimbic structures. However, it is unclear whether such features are already present during earlier stages of adulthood, and if age-related GM changes may follow non-linear patterns at such age range. This voxel-based morphometry study investigated the relationship between GM volumes and age specifically during non-elderly life (18-50 years) in 89 healthy individuals (48 males and 41 females). Voxelwise analyses showed significant (p < 0.05, corrected) negative correlations in the right prefrontal cortex and left cerebellum, and positive correlations (indicating lack of GM loss) in the medial temporal region, cingulate gyrus, insula and temporal neocortex. Analyses using ROI masks showed that age-related dorsolateral prefrontal volume decrements followed non-linear patterns, and were less prominent in females compared to males at this age range. These findings further support for the notion of a heterogeneous and asynchronous pattern of age-related brain morphometric changes, with region-specific non-linear features.
- Chronic Traumatic Encephalopathy Presenting as Alzheimer's Disease in a Retired Soccer Player(2016) GRINBERG, Lea T.; ANGHINAH, Renato; NASCIMENTO, Camila Fernandes; AMARO JR., Edson; LEITE, Renata P.; MARTIN, Maria da Graca M.; NASLAVSKY, Michel S.; TAKADA, Leonel T.; JACOB FILHO, Wilson; PASQUALUCCI, Carlos A.; NITRINI, RicardoThe relationship between soccer and chronic traumatic encephalopathy (CTE) is not well established. We report clinicopathological correlations in an 83-year-old retired center-back soccer player, with no history of concussion, manifesting typical Alzheimer-type dementia. Examination revealed mixed pathology including widespread CTE, moderate Alzheimer's disease, hippocampal sclerosis, and TDP-43 proteinopathy. This case adds to a few CTE cases described in soccer players. Furthermore, it corroborates that CTE may present clinically as typical Alzheimer-type dementia. Further studies investigating the extent to which soccer is a risk for CTE are needed.
- Magnetic resonance diffusion tensor imaging for the pedunculopontine nucleus: proof of concept and histological correlation(2017) ALHO, A. T. D. L.; HAMANI, C.; ALHO, E. J. L.; SILVA, R. E. da; SANTOS, G. A. B.; NEVES, R. C.; CARREIRA, L. L.; ARAUJO, C. M. M.; MAGALHAES, G.; COELHO, D. B.; ALEGRO, M. C.; MARTIN, M. G. M.; GRINBERG, L. T.; PASQUALUCCI, C. A.; HEINSEN, H.; FONOFF, E. T.; AMARO JR., E.The pedunculopontine nucleus (PPN) has been proposed as target for deep brain stimulation (DBS) in patients with postural instability and gait disorders due to its involvement in muscle tonus adjustments and control of locomotion. However, it is a deep-seated brainstem nucleus without clear imaging or electrophysiological markers. Some studies suggested that diffusion tensor imaging (DTI) may help guiding electrode placement in the PPN by showing the surrounding fiber bundles, but none have provided a direct histological correlation. We investigated DTI fractional anisotropy (FA) maps from in vivo and in situ postmortem magnetic resonance images (MRI) compared to histological evaluations for improving PPN targeting in humans. A post-mortem brain was scanned in a clinical 3T MR system in situ. Thereafter, the brain was processed with a special method ideally suited for cytoarchitectonic analyses. Also, nine volunteers had in vivo brain scanning using the same MRI protocol. Images from volunteers were compared to those obtained in the post-mortem study. FA values of the volunteers were obtained from PPN, inferior colliculus, cerebellar crossing fibers and medial lemniscus using histological data and atlas information. FA values in the PPN were significantly lower than in the surrounding white matter region and higher than in areas with predominantly gray matter. In Nissl-stained histologic sections, the PPN extended for more than 10 mm in the rostro-caudal axis being closely attached to the lateral parabrachial nucleus. Our DTI analyses and the spatial correlation with histological findings proposed a location for PPN that matched the position assigned to this nucleus in the literature. Coregistration of neuroimaging and cytoarchitectonic features can add value to help establishing functional architectonics of the PPN and facilitate neurosurgical targeting of this extended nucleus.
- Fluid-Attenuated Inversion Recovery Vascular Hyperintensities in Patients with Transient Ischemic Attack(2017) FIGUEIREDO, Marcelo Marinho de; AMARO JUNIOR, Edson; ALVES, Maramelia Araujo de Miranda; VAZZOLER, Marcela; MIRANDA, Renata Carolina Acre Nunes; SILVA, Gisele SampaioBackground: Fluid-attenuated inversion recovery (FLAIR) vascular hyperintensities (FVHs) are common in patients with acute ischemic stroke, possibly representing impaired hemodynamics in the ischemic territory due to intracranial steno-occlusive disease. There are few reports on FVHs in patients with transient ischemic attack (TIA). Aims: We investigated the prevalence of FVHs and its clinical correlations in patients with TIA. Methods: We evaluated consecutive patients admitted with TIA from February 2009 to June 2012 who had undergone magnetic resonance imaging within 30 hours of symptoms onset and intracranial and extracranial vascular imaging. Two independent neuroradiologists determined the presence of FVHs. We assessed the relationship between FVHs, clinical presentation, vascular risk factors, neuroimaging characteristics, and the presence of large artery stenosis or occlusion. Results: Seventy-two patients with TIA were evaluated. FVHs were present in 12 (16.7%) patients. The overall agreement between examiners was good (kappa =.67). There were no differences in the frequency of intracranial or cervical arterial stenosis in patients with and without FVH. In a multivariate logistic regression analysis including atrial fibrillation (AF), congestive heart failure, and diabetes, only AF remained in the final model. Conclusions: FVH signals on FLAIR images occur in patients with TIA and might correlate with clinical variables like AF and not only with large vessel occlusion. The presence of FVH in patients with TIA and AF might be a surrogate marker for a large vessel occlusion spontaneously recanalized or for impaired autoregulation in a previously ischemic vascular territory.