FABIO HENRIQUE DE GOBBI PORTO
Projetos de Pesquisa
Unidades Organizacionais
Instituto de Psiquiatria, Hospital das Clínicas, Faculdade de Medicina
LIM/21 - Laboratório de Neuroimagem em Psiquiatria, Hospital das Clínicas, Faculdade de Medicina
LIM/21 - Laboratório de Neuroimagem em Psiquiatria, Hospital das Clínicas, Faculdade de Medicina
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- Deficits in short-term memory binding are detectable in individuals with brain amyloid deposition in the absence of overt neurodegeneration in the Alzheimer's disease continuum(2021) CECCHINI, Mario Amore; YASSUDA, Monica Sanches; SQUARZONI, Paula; COUTINHO, Artur Martins; FARIA, Daniele de Paula; DURAN, Fabio Luiz de Souza; COSTA, Naomi Antunes da; PORTO, Fabio Henrique de Gobbi; NITRINI, Ricardo; FORLENZA, Orestes Vicente; BRUCKI, Sonia Maria Dozzi; BUCHPIGUEL, Carlos Alberto; PARRA, Mario A.; BUSATTO, Geraldo F.The short-term memory binding (STMB) test involves the ability to hold in memory the integration between surface features, such as shapes and colours. The STMB test has been used to detect Alzheimer's disease (AD) at different stages, from preclinical to dementia, showing promising results. The objective of the present study was to verify whether the STMB test could differentiate patients with distinct biomarker profiles in the AD continuum. The sample comprised 18 cognitively unimpaired (CU) participants, 30 mild cognitive impairment (MCI) and 23 AD patients. All participants underwent positron emission tomography (PET) with Pittsburgh compound B labelled with carbon-11 ([C-11]PIB) assessing amyloid beta (A beta) aggregation (A) and 18fluorine-fluorodeoxyglucose ([F-18]FDG)-PET assessing neurodegeneration (N) (A -N-[n = 35]); A+N-[n = 11]; A+ N+ [n = 19]). Participants who were negative and positive for amyloid deposition were compared in the absence (A-N vs. A+N-) of neurodegeneration. When compared with the RAVLT and SKT memory tests, the STMB was the only cognitive task that differentiated these groups, predicting the group outcome in logistic regression analyses. The STMB test showed to be sensitive to the signs of AD pathology and may represent a cognitive marker within the AD continuum.
- Brain PET amyloid and neurodegeneration biomarkers in the context of the 2018 NIA-AA research framework: an individual approach exploring clinical-biomarker mismatches and sociodemographic parameters(2020) COUTINHO, Artur Martins; BUSATTO, Geraldo F.; PORTO, Fabio Henrique de Gobbi; FARIA, Daniele de Paula; ONO, Carla Rachel; GARCEZ, Alexandre Teles; SQUARZONI, Paula; DURAN, Fabio Luiz de Souza; OLIVEIRA, Maira Okada de; TRES, Eduardo Sturzeneker; BRUCKI, Sonia Maria Dozzi; FORLENZA, Orestes Vicente; NITRINI, Ricardo; BUCHPIGUEL, Carlos AlbertoPurpose [F-18]FDG-PET and [C-11]PIB-PET are validated as neurodegeneration and amyloid biomarkers of Alzheimer's disease (AD). We used a PET staging system based on the 2018 NIA-AA research framework to compare the proportion of amyloid positivity (A+) and hypometabolism ((N)+) in cases of mild probable AD, amnestic mild cognitive impairment (aMCI), and healthy controls, incorporating an additional classification of abnormal [F-18]FDG-PET patterns and investigating the co-occurrence of such with A+, exploring [F-18]FDG-PET to generate hypotheses in cases presenting with clinical-biomarker ""mismatches."" Methods Elderly individuals (N = 108) clinically classified as controls (N = 27), aMCI (N = 43) or mild probable AD (N = 38) were included. Authors assessed their A(N) profiles and classified [F-18]FDG-PET neurodegenerative patterns as typical or non-typical of AD, performing re-assessments of images whenever clinical classification was in disagreement with the PET staging (clinical-biomarker ""mismatches""). We also investigated associations between ""mismatches"" and sociodemographic and educational characteristics. Results AD presented with higher rates of A+ and (N)+. There was also a higher proportion of A+ and (N)+ individuals in the aMCI group in comparison to controls, however without statistical significance regarding the A staging. There was a significant association between amyloid positivity and AD (N)+ hypometabolic patterns typical of AD. Non-AD (N)+ hypometabolism was seen in all A- (N)+ cases in the mild probable AD and control groups and [F-18]FDG-PET patterns classified such individuals as ""SNAP"" and one as probable frontotemporal lobar degeneration. All A- (N)- cases in the probable AD group had less than 4 years of formal education and lower socioeconomic status (SES). Conclusion The PET-based staging system unveiled significant A(N) differences between AD and the other groups, whereas aMCI and controls had different (N) staging, explaining the cognitive impairment in aMCI. [F-18]FDG-PET could be used beyond simple (N) staging, since it provided alternative hypotheses to cases with clinical-biomarker ""mismatches."" An AD hypometabolic pattern correlated with amyloid positivity. Low education and SES were related to dementia in the absence of biomarker changes.
- Relationship Between PET-Assessed Amyloid Burden and Visual and Verbal Episodic Memory Performance in Elderly Subjects(2020) SQUARZONI, Paula; FARIA, Daniele de Paula; YASSUDA, Monica Sanches; PORTO, Fabio Henrique de Gobbi; COUTINHO, Artur Martins; COSTA, Naomi Antunes da; NITRINI, Ricardo; FORLENZA, Orestes Vicente; DURAN, Fabio Luiz de Souza; BRUCKI, Sonia Maria Dozzi; BUCHPIGUEL, Carlos Alberto; BUSATTO, Geraldo F.Background: Studies of elderly subjects using biomarkers that are proxies for Alzheimer's disease (AD) pathology have the potential to document meaningful relationships between cognitive performance and biomarker changes along the AD continuum. Objective: To document cognitive performance differences across distinct AD stages using a categorization based on the presence of PET-assessed amyloid-beta (A beta) burden and neurodegeneration. Methods: Patients with mild dementia compatible with AD (n = 38) or amnestic mild cognitive impairment (aMCI; n = 43) and a cognitively unimpaired group (n = 27) underwent PET with Pittsburgh compound-B (PiB) assessing A beta aggregation (A+) and [F-18]FDG-PET assessing neurodegeneration ((N)+). Cognitive performance was assessed with verbal and visual episodic memory tests and the Mini-Mental State Examination. Results: The A+(N)+ subgroup (n = 32) showed decreased (p < 0.001) cognitive test scores compared to both A+(N)-(n = 18) and A-(N)- (n = 49) subjects, who presented highly similar mean cognitive scores. Despite its modest size (n = 9), the A-(N)+ subgroup showed lower (p < 0.043) verbal memory scores relative to A-(N)- subjects, and trend lower (p = 0.096) scores relative to A+(N)- subjects. Continuous A beta measures (standard uptake value ratios of PiB uptake) were correlated most significantly with visual memory scores both in the overall sample and when analyses were restricted to dementia or (N)+ subjects, but not in non-dementia or (N)- groups. Conclusion: These results demonstrate that significant A beta-cognition relationships are highly salient at disease stages involving neurodegeneration. The fact that findings relating A beta burden to memory performance were detected only at (N)+ stages, together with the similarity of test scores between A+(N)- and A-(N)- subjects, reinforce the view that A beta-cognition relationships during early AD stages may remain undetectable unless substantially large samples are evaluated.