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OBJECTIVES: Although a large number of studies have shown brain volumetric differences between men and women, only a few investigations have analyzed brain tissue volumes in representative samples of the general elderly population. We investigated differences in gray matter (GM) volumes, white matter (WM) volumes, and intracranial volumes (ICVs) between the sexes in individuals older than 66 years using structural magnetic resonance imaging (MRI). METHODS: Using FreeSurfer version 5.3, we obtained the ICVs and GM and WM volumes from the MRI datasets of 84 men and 92 women. To correct for interindividual variations in ICV, GM and WM volumes were adjusted with a method using the residuals of a least-square-derived linear regression between raw volumes and ICVs. We then performed an analysis of covariance comparing men and women, including age and years of schooling as confounding factors. RESULTS: Women had a lower socioeconomic status overall and fewer years of schooling than men. The comparison of unadjusted brain volumes showed larger GM and WM volumes in men. After the ICV correction, the adjusted volumes of GM and WM were larger in women. CONCLUSION: After the ICV correction and taking into account differences in socioeconomic status and years of schooling, our results confirm previous findings of proportionally larger GM in women, as well as larger WM volumes. These results in an elderly population indicate that brain volumetric differences between sexes persist throughout the aging process. Additional studies combining MRI and other biomarkers to identify the hormonal and molecular bases influencing such differences are warranted.
Assuntos
Encéfalo , Substância Branca , Idoso , Encéfalo/diagnóstico por imagem , Feminino , Substância Cinzenta/diagnóstico por imagem , Humanos , Modelos Lineares , Imageamento por Ressonância Magnética , MasculinoRESUMO
OBJECTIVES: Although a large number of studies have shown brain volumetric differences between men and women, only a few investigations have analyzed brain tissue volumes in representative samples of the general elderly population. We investigated differences in gray matter (GM) volumes, white matter (WM) volumes, and intracranial volumes (ICVs) between the sexes in individuals older than 66 years using structural magnetic resonance imaging (MRI). METHODS: Using FreeSurfer version 5.3, we obtained the ICVs and GM and WM volumes from the MRI datasets of 84 men and 92 women. To correct for interindividual variations in ICV, GM and WM volumes were adjusted with a method using the residuals of a least-square-derived linear regression between raw volumes and ICVs. We then performed an analysis of covariance comparing men and women, including age and years of schooling as confounding factors. RESULTS: Women had a lower socioeconomic status overall and fewer years of schooling than men. The comparison of unadjusted brain volumes showed larger GM and WM volumes in men. After the ICV correction, the adjusted volumes of GM and WM were larger in women. CONCLUSION: After the ICV correction and taking into account differences in socioeconomic status and years of schooling, our results confirm previous findings of proportionally larger GM in women, as well as larger WM volumes. These results in an elderly population indicate that brain volumetric differences between sexes persist throughout the aging process. Additional studies combining MRI and other biomarkers to identify the hormonal and molecular bases influencing such differences are warranted.
Assuntos
Humanos , Masculino , Feminino , Idoso , Encéfalo/diagnóstico por imagem , Substância Branca , Imageamento por Ressonância Magnética , Modelos Lineares , Substância Cinzenta/diagnóstico por imagemRESUMO
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 (São 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.
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Doenças Assintomáticas/epidemiologia , Infarto Encefálico/complicações , Infarto Encefálico/epidemiologia , Disfunção Cognitiva/epidemiologia , Disfunção Cognitiva/etiologia , Fatores Etários , Idoso , Análise de Variância , Infarto Encefálico/fisiopatologia , Brasil/epidemiologia , Disfunção Cognitiva/fisiopatologia , Feminino , Humanos , Testes de Inteligência , Imageamento por Ressonância Magnética , Masculino , Testes Neuropsicológicos , Prevalência , Escalas de Graduação Psiquiátrica , Valores de Referência , Medição de Risco , Fatores de Risco , Fatores SocioeconômicosRESUMO
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 APOEε4 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.
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Objective: To review functional neuroimaging studies about the relationship between cardiovascular risk factors (CVRFs), Alzheimer's disease (AD), and mild cognitive impairment (MCI). Methods: We performed a comprehensive literature search to identify articles in the neuroimaging field addressing CVRF in AD and MCI. We included studies that used positron emission tomography (PET), single photon emission computerized tomography (SPECT), or functional magnetic resonance imaging (fMRI). Results: CVRFs have been considered risk factors for cognitive decline, MCI, and AD. Patterns of AD-like changes in brain function have been found in association with several CVRFs (both regarding individual risk factors and also composite CVRF measures). In vivo assessment of AD-related pathology with amyloid imaging techniques provided further evidence linking CVRFs and AD, but there is still limited information resulting from this new technology. Conclusion: There is a large body of evidence from functional neuroimaging studies supporting the hypothesis that CVRFs may play a causal role in the pathophysiology of AD. A major limitation of most studies is their cross-sectional design; future longitudinal studies using multiple imaging modalities are expected to better document changes in CVRF-related brain function patterns and provide a clearer picture of the complex relationship between aging, CVRFs, and AD. .
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Humanos , Doença de Alzheimer/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Neuroimagem Funcional/métodos , Disfunção Cognitiva/fisiopatologia , Doença de Alzheimer/diagnóstico , Doenças Cardiovasculares/diagnóstico , Imageamento por Ressonância Magnética/métodos , Disfunção Cognitiva/diagnóstico , Tomografia por Emissão de Pósitrons/métodos , Fatores de Risco , Tomografia Computadorizada de Emissão de Fóton Único/métodosRESUMO
OBJECTIVE: To review functional neuroimaging studies about the relationship between cardiovascular risk factors (CVRFs), Alzheimer's disease (AD), and mild cognitive impairment (MCI). METHODS: We performed a comprehensive literature search to identify articles in the neuroimaging field addressing CVRF in AD and MCI. We included studies that used positron emission tomography (PET), single photon emission computerized tomography (SPECT), or functional magnetic resonance imaging (fMRI). RESULTS: CVRFs have been considered risk factors for cognitive decline, MCI, and AD. Patterns of AD-like changes in brain function have been found in association with several CVRFs (both regarding individual risk factors and also composite CVRF measures). In vivo assessment of AD-related pathology with amyloid imaging techniques provided further evidence linking CVRFs and AD, but there is still limited information resulting from this new technology. CONCLUSION: There is a large body of evidence from functional neuroimaging studies supporting the hypothesis that CVRFs may play a causal role in the pathophysiology of AD. A major limitation of most studies is their cross-sectional design; future longitudinal studies using multiple imaging modalities are expected to better document changes in CVRF-related brain function patterns and provide a clearer picture of the complex relationship between aging, CVRFs, and AD.
Assuntos
Doença de Alzheimer/fisiopatologia , Doenças Cardiovasculares/fisiopatologia , Disfunção Cognitiva/fisiopatologia , Neuroimagem Funcional/métodos , Doença de Alzheimer/diagnóstico , Doenças Cardiovasculares/diagnóstico , Disfunção Cognitiva/diagnóstico , Humanos , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos , Fatores de Risco , Tomografia Computadorizada de Emissão de Fóton Único/métodosRESUMO
PURPOSE OF REVIEW: To review neuroimaging findings that have been reported in samples of patients with cardiovascular disorders and their association with the onset of Alzheimer's disease, vascular dementia, depression and bipolar disorder in the elderly and to highlight the implications of these findings to the knowledge about the pathophysiology of psychiatric disorders in old age, as well as their potential clinical implications. RECENT FINDINGS: Vascular risk factors, such as hypertension, diabetes, dyslipidemia, smoking habits and heart failure, have all been associated with signs of cerebrovascular dysfunction, including structural MRI findings of signal hyperintensities, lacunes and stroke and functional imaging findings of brain regional hypoperfusion and hypometabolism. Such brain abnormalities have been found to increase the risk of onset of psychiatric disorder (depression, bipolar and dementia) in old age. SUMMARY: As vascular risk factors are potentially modifiable when detected in midlife, the early characterization of brain changes associated with the presence of cardiovascular diseases holds promise to afford clinical applications in psychiatry, providing new perspectives for the prevention of old age psychiatric disorders.
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Encéfalo/diagnóstico por imagem , Doenças Cardiovasculares/diagnóstico por imagem , Transtornos Mentais/diagnóstico por imagem , Idoso , Encéfalo/patologia , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/patologia , Humanos , Leucoencefalopatias/complicações , Leucoencefalopatias/diagnóstico por imagem , Leucoencefalopatias/patologia , Transtornos Mentais/complicações , Transtornos Mentais/patologia , Transtornos do Humor/complicações , Transtornos do Humor/diagnóstico por imagem , Transtornos do Humor/patologia , RadiografiaRESUMO
The authors evaluated levels of inflammatory markers in 34 chronic heart failure (CHF) out-patients age 65 years and over, with (N=18) and without (N=16) major depressive disorder (MDD), and healthy-control subjects (N=13). Patients with CHF had left-ventricular ejection fractions <0.40 and were in the New York Heart Association functional class II or III. The authors used the SCID DSM-IV to diagnosis MDD. High-sensitivity C-reactive protein levels were significantly higher in patients with CHF and MDD as compared with healthy-control subjects. No differences regarding tumor necrosis factor(alpha) or interleukin(6) were found among the three groups.
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Proteína C-Reativa/metabolismo , Transtorno Depressivo Maior/sangue , Transtorno Depressivo Maior/epidemiologia , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/epidemiologia , Interleucina-6/sangue , Fator de Necrose Tumoral alfa/sangue , Idoso , Biomarcadores , Transtorno Depressivo Maior/diagnóstico , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Humanos , Masculino , PrevalênciaRESUMO
Cognitive deficits are common in association with heart failure (HF), and it is possible that their severity is magnified by the concomitant presence of major depressive disorder (MDD). Using the Cambridge Mental Disorders of the Elderly Examination battery, the authors compared the cognitive performance of MDD-HF subjects (N=20), nondepressed HF subjects (N=23), and healthy control subjects (N=18). Scores were lower in both HF groups relative to control subjects. In the MDD-HF group, there were significant cognitive improvements after antidepressant treatment. Cognitive impairment is, therefore, significant in HF subjects with or without comorbid MDD, and it is important to recognize and treat MDD symptoms associated with HF.
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Antidepressivos de Segunda Geração/uso terapêutico , Antidepressivos/uso terapêutico , Citalopram/uso terapêutico , Transtornos Cognitivos/diagnóstico , Transtorno Depressivo Maior/tratamento farmacológico , Insuficiência Cardíaca/psicologia , Inibidores Seletivos de Recaptação de Serotonina/uso terapêutico , Sertralina/uso terapêutico , Disfunção Ventricular Esquerda/psicologia , Idoso , Idoso de 80 Anos ou mais , Antidepressivos/efeitos adversos , Citalopram/efeitos adversos , Transtornos Cognitivos/complicações , Transtornos Cognitivos/psicologia , Transtorno Depressivo Maior/complicações , Transtorno Depressivo Maior/psicologia , Feminino , Avaliação Geriátrica , Insuficiência Cardíaca/complicações , Humanos , Masculino , Entrevista Psiquiátrica Padronizada/estatística & dados numéricos , Testes Neuropsicológicos , Psicometria , Sertralina/efeitos adversos , Resultado do Tratamento , Disfunção Ventricular Esquerda/complicaçõesRESUMO
BACKGROUND AND PURPOSE: Depressive symptoms are frequently associated with heart failure (HF), but the brain mechanisms underlying such association are unclear. We hypothesized that the presence of major depressive disorder (MDD) emerging after the onset of HF would be associated with regional cerebral blood flow (rCBF) abnormalities in medial temporal regions previously implicated in primary MDD, namely the hippocampus and parahippocampal gyrus. METHOD: Using 99mTc-SPECT, we measured rCBF in 17 elderly MDD-HF patients, 17 non-depressed HF patients, and 18 healthy controls, matched for demographic variables. Group differences were investigated with Statistical Parametric Mapping. RESULTS: Significant rCBF reductions in MDD-HF patients relative to both non-depressed HF patients and healthy controls were detected in the left anterior parahippocampal gyrus and hippocampus (ANOVA, p=0.008 corrected for multiple comparisons) and the right posterior hippocampus and parahippocampal gyrus (p=0.005 corrected). In the overall HF group, there was a negative correlation between the severity of depressive symptoms and rCBF in the right posterior hippocampal/parahippocampal region (p=0.045 corrected). CONCLUSIONS: These findings are consistent with the notion that the medial temporal region is vulnerable to brain perfusion deficits associated with HF, and provide evidence that such functional deficits may be specifically implicated in the pathophysiology of MDD associated with HF.