Differences in Total Brain Volume between Sexes in a Cognitively Unimpaired Elderly Population.

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.

Differences in total brain volume between sexes in a cognitively unimpaired elderly population

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.

High frequency of silent brain infarcts associated with cognitive deficits in an economically disadvantaged population.

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.

Major depressive disorder and inflammatory markers in elderly patients with heart failure.

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.

Effects of antidepressant treatment on cognitive performance in elderly subjects with heart failure and comorbid major depression: an exploratory study.

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.

Association between major depressive symptoms in heart failure and impaired regional cerebral blood flow in the medial temporal region: a study using 99m Tc-HMPAO single photon emission computerized tomography (SPECT).

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.

Localized cerebral blood flow reductions in patients with heart failure: a study using 99mTc-HMPAO SPECT.

BACKGROUND AND PURPOSE: Reduced resting global cerebral blood flow has been previously detected in association with heart failure (HF), but it is not clear whether there are brain regions that could be specifically affected by those brain perfusion deficits. The authors used a fully automated, voxel-based image analysis method to investigate, across the entire cerebral volume, the presence of resting regional cerebral blood flow (rCBF) abnormalities in HF patients compared to healthy controls. METHODS: rCBF was evaluated with 99mTc-single-photon emission computed tomography in 17 HF patients (New York Heart Association functional class II or III) and 18 elderly healthy volunteers. Voxel-based analyses of rCBF data were conducted using the statistical parametric mapping software. RESULTS: Significant rCBF reductions in HF patients relative to controls (P<.05, corrected for multiple comparisons) were detected in 2 foci, encompassing, respectively, the left and right precuneus and cuneus and the right lateral temporoparietal cortex and posterior cingulated gyrus. In the HF group, there was also a significant direct correlation between the degree of cognitive impairment as assessed using the Cambridge Mental Disorders of the Elderly Examination and rCBF on a voxel cluster involving the right posterior cingulate cortex and precuneus, located closely to the site where between-group rCBF differences had been identified. CONCLUSIONS: These preliminary findings indicate that posterior cortical areas of the brain may be particularly vulnerable to brain perfusion reductions associated with HF and suggest that functional deficits in these regions might be relevant to the pathophysiology of the cognitive impairments presented by HF patients.