MAURICIO WAJNGARTEN
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- Cardiovascular risk in cognitively preserved elderlies is associated with glucose hypometabolism in the posterior cingulate cortex and precuneus regardless of brain atrophy and apolipoprotein gene variations(2013) TAMASHIRO-DURAN, Jaqueline Hatsuko; SQUARZONI, Paula; DURAN, Fabio Luis de Souza; CURIATI, Pedro Kallas; VALLADA, Homero Pinto; BUCHPIGUEL, Carlos Alberto; LOTUFO, Paulo Andrade; WAJNGARTEN, Mauricio; MENEZES, Paulo Rossi; SCAZUFCA, Marcia; ALVES, Tania Correa de Toledo Ferraz; BUSATTO, Geraldo FilhoCardiovascular risk factors (CVRF) possibly contribute to the emergence of Alzheimer's disease (AD). Fluorodeoxyglucose-positron emission tomography (FDG-PET) has been widely used to demonstrate specific patterns of reduced cerebral metabolic rates of glucose (CMRgl) in subjects with AD and in non-demented carriers of the apolipoprotein epsilon 4 (APOE epsilon 4) allele, the major genetic risk factor for AD. However, functional neuroimaging studies investigating the impact of CVRF on cerebral metabolism have been scarce to date. The present FDG-PET study investigated 59 cognitively preserved elderlies divided into three groups according to their cardiovascular risk based on the Framingham 10-year risk Coronary Heart Disease Risk Profile (low-, medium-, and high-risk) to examine whether different levels of CVRF would be associated with reduced CMRgl, involving the same brain regions affected in early stages of AD. Functional imaging data were corrected for partial volume effects to avoid confounding effects due to regional brain atrophy, and all analyses included the presence of the APOE epsilon 4 allele as a confounding covariate. Significant cerebral metabolism reductions were detected in the high-risk group when compared to the low-risk group in the left precuneus and posterior cingulate gyrus. This suggests that findings of brain hypometabolism similar to those seen in subjects with AD can be detected in association with the severity of cardiovascular risk in cognitively preserved individuals. Thus, a greater knowledge about how such factors influence brain functioning in healthy subjects over time may provide important insigths for the future development of strategies aimed at delaying or preventing the vascular-related triggering of pathologic brain changes in the AD.
- Prefrontal-Parietal White Matter Volumes in Healthy Elderlies Are Decreased in Proportion to the Degree of Cardiovascular Risk and Related to Inhibitory Control Deficits(2017) SANTOS, Pedro P.; SILVEIRA, Paula S. Da; SOUZA-DURAN, Fabio L.; TAMASHIRO-DURAN, Jaqueline H.; SCAZUFCA, Marcia; MENEZES, Paulo R.; LEITE, Claudia Da Costa; LOTUFO, Paulo A.; VALLADA, Homero; WAJNGARTEN, Mauricio; ALVES, Tania C. De Toledo Ferraz; RZEZAK, Patricia; BUSATTO, Geraldo F.Cardiovascular risk (CVR) factors may be associated with poor cognitive functioning in elderlies and impairments in brain structure. Using MRI and voxel-based morphometry (VBM), we assessed regional white matter (WM) volumes in a population-based sample of individuals aged 65-75 years (n = 156), subdivided in three CVR subgroups using the Framingham Risk Score. Cognition was assessed using the Short Cognitive Performance Test. In high-risk subjects, we detected significantly reduced WM volume in the right juxtacortical dorsolateral prefrontal region compared to both low and intermediate CVR subgroups. Findings remained significant after accounting for the presence of the APOE epsilon 4 allele. Inhibitory control performance was negatively related to right prefrontal WM volume, proportionally to the degree of CVR. Significantly reduced deep parietal WM was also detected bilaterally in the high CVR subgroup. This is the first large study documenting the topography of CVR-related WM brain volume deficits. The significant association regarding poor response inhibition indicates that prefrontal WM deficits related to CVR are clinically meaningful, since inhibitory control is known to rely on prefrontal integrity.
- Subtle Gray Matter Changes in Temporo-Parietal Cortex Associated with Cardiovascular Risk Factors(2011) DE TOLEDO FERRAZ ALVES, Tania Correa; SCAZUFCA, Marcia; SQUARZONI, Paula; DE SOUZA DURAN, Fabio Luiz; TAMASHIRO-DURAN, Jaqueline Hatsuko; VALLADA, Homero P.; ANDREI, Anna; WAJNGARTEN, Mauricio; MENEZES, Paulo R.; BUSATTO, Geraldo F.Vascular risk factors may play an important role in the pathophysiology of Alzheimer's disease (AD). While there is consistent evidence of gray matter (GM) abnormalities in earlier stages of AD, the presence of more subtle GM changes associated with vascular risk factors in the absence of clinically significant vascular events has been scarcely investigated. This study aimed to examine GM changes in elderly subjects with cardiovascular risk factors. We predicted that the presence of cardiovascular risk would be associated with GM abnormalities involving the temporal-parietal cortices and limbic structures. We recruited 248 dementia-free subjects, age range 66-75 years, from the population-based "Sao Paulo Ageing and Health Study", classified in accordance to their Framingham Coronary Heart Disease Risk (FCHDR) score to undergo an MRI scan. We performed an overall analysis of covariance, controlled to total GM and APOE4 status, to investigate the presence of regional GM abnormalities in association with FCHDR subgroups (high-risk, medium-risk, and low-risk), and followed by post hoc t-test. We also applied a co-relational design in order to investigate the presence of linear progression of the GM vulnerability in association with cardiovascular risk factor. Voxel-based morphometry showed that the presence of cardiovascular risk factors were associated with regional GM loss involving the temporal cortices bilaterally. Those results retained statistical significance after including APOE4 as a covariate of interest. We also observed that there was a negative correlation between FCHDR scores and rGM distribution in the parietal cortex. Subclinical cerebrovascular abnormalities involving GM loss may provide an important link between cardiovascular risk factors and AD.
- High frequency of silent brain infarcts associated with cognitive deficits in an economically disadvantaged population(2017) SQUARZONI, Paula; TAMASHIRO-DURAN, Jaqueline H.; DURAN, Fabio L. S.; LEITE, Claudia C.; WAJNGARTEN, Mauricio; SCAZUFCA, Marcia; MENEZES, Paulo R.; LOTUFO, Paulo A.; ALVES, Tania C. T. F.; BUSATTO, Geraldo F.OBJECTIVE: Using magnetic resonance imaging, we aimed to assess the presence of silent brain vascular lesions in a sample of apparently healthy elderly individuals who were recruited from an economically disadvantaged urban region (Sao Paulo, Brazil). We also wished to investigate whether the findings were associated with worse cognitive performance. METHODS: A sample of 250 elderly subjects (66-75 years) without dementia or neuropsychiatric disorders were recruited from predefined census sectors of an economically disadvantaged area of Sao Paulo and received structural magnetic resonance imaging scans and cognitive testing. A high proportion of individuals had very low levels of education (4 years or less, n= 185; 21 with no formal education). RESULTS: The prevalence of at least one silent vascular-related cortical or subcortical lesion was 22.8% (95% confidence interval, 17.7-28.5), and the basal ganglia was the most frequently affected site (63.14% of cases). The subgroup with brain infarcts presented significantly lower levels of education than the subgroup with no brain lesions as well as significantly worse current performance in cognitive test domains, including memory and attention (p<0.002). CONCLUSIONS: Silent brain infarcts were present at a substantially high frequency in our elderly sample from an economically disadvantaged urban region and were significantly more prevalent in subjects with lower levels of education. Covert cerebrovascular disease significantly contributes to cognitive deficits, and in the absence of magnetic resonance imaging data, this cognitive impairment may be considered simply related to ageing. Emphatic attention should be paid to potentially deleterious effects of vascular brain lesions in poorly educated elderly individuals from economically disadvantaged environments.