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Normal Elderly Subjects (normal + elderly_subject)
Selected AbstractsBrain structure and obesityHUMAN BRAIN MAPPING, Issue 3 2010Cyrus A. Raji Abstract Obesity is associated with increased risk for cardiovascular health problems including diabetes, hypertension, and stroke. These cardiovascular afflictions increase risk for cognitive decline and dementia, but it is unknown whether these factors, specifically obesity and Type II diabetes, are associated with specific patterns of brain atrophy. We used tensor-based morphometry (TBM) to examine gray matter (GM) and white matter (WM) volume differences in 94 elderly subjects who remained cognitively normal for at least 5 years after their scan. Bivariate analyses with corrections for multiple comparisons strongly linked body mass index (BMI), fasting plasma insulin (FPI) levels, and Type II Diabetes Mellitus (DM2) with atrophy in frontal, temporal, and subcortical brain regions. A multiple regression model, also correcting for multiple comparisons, revealed that BMI was still negatively correlated with brain atrophy (FDR <5%), while DM2 and FPI were no longer associated with any volume differences. In an Analysis of Covariance (ANCOVA) model controlling for age, gender, and race, obese subjects with a high BMI (BMI > 30) showed atrophy in the frontal lobes, anterior cingulate gyrus, hippocampus, and thalamus compared with individuals with a normal BMI (18.5,25). Overweight subjects (BMI: 25,30) had atrophy in the basal ganglia and corona radiata of the WM. Overall brain volume did not differ between overweight and obese persons. Higher BMI was associated with lower brain volumes in overweight and obese elderly subjects. Obesity is therefore associated with detectable brain volume deficits in cognitively normal elderly subjects. Hum Brain Mapp, 2010. © 2009 Wiley-Liss, Inc. [source] The clock drawing test in primary care: sensitivity in dementia detection and specificity against normal and depressed elderlyINTERNATIONAL JOURNAL OF GERIATRIC PSYCHIATRY, Issue 10 2001Michael Kirby Abstract Objectives The aim of this study was to examine the sensitivities and specificities of the clock drawing test (CDT) in the detection of dementia among older people in primary care, with particular emphasis on the effect of depression on CDT specificity. Most previous studies have been sited in specialist settings and few have addressed the issue of specificity aginst depression. Methods Comparison of cohorts identified from community-based screening with GMS-AGECAT. The CDT and the Mini-Mental State Examination (MMSE) were administered to 41 elderly subjects with organic disorder (dementia), 84 elderly subjects with case level depression and 523 normal elderly subjects. Sensitivities and specificities of the CDT were calculated. Results The sensitivity of the CDT in the detection of dementia in the general community was 76%. The specificities of the CDT against normal elderly and depressed elderly was 81% and 77% respectively. Higher sensitivity and specificity were achieved by the MMSE. Conclusions The use of the CDT in the detection of dementia syndromes is likely to be more relevant in the primary care context than in specialist settings. The CDT provides good sensitivity and specificity but may not be as sensitive or specific in the general community as previous studies have suggested, particularly in mild dementia. Community-based late life depression does not appear to alter the specificity of the CDT. Copyright © 2001 John Wiley & Sons, Ltd. [source] Metabolic Markers of Cobalamin Deficiency and Cognitive Function in Normal Older AdultsJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 1 2004Angeles A. Garcia MD, FRCPC Objectives: To investigate the relationship between metabolic markers of cobalamin deficiency and cognitive function in normal older adults. Design: Cross-sectional study. Setting: Queen's University and St. Mary's of the Lake Hospital, Kingston, Ontario, Canada. Participants: Two hundred eighty-one cognitively normal, community-dwelling participants aged 65 and older. Measurements: Serum cobalamin, red blood cell folate, methylcitric acid, homocysteine, and methylmalonic acid were determined. Cognitive instruments included the California Verbal Learning Test, Mattis Dementia Rating Scale, and the Stroop Neuropsychological Screening Inventory (Stroop). Results: Serum levels of methylcitric acid had a significant negative correlation with recall, learning, and discriminability (factor 1) of the California Verbal Learning Test after adjusting for age and sex (,=,0.138, P=.019). Subjects with elevated methylcitric acid had significantly lower scores (factor 1) than subjects with normal methylcitric acid (P<.01). Bivariate analysis showed significant correlations between levels of homocysteine and the Stroop score and between cobalamin, methylmalonic acid, and homocysteine and some scores of the California Verbal Learning Test, but these relationships did not remain significant after multivariate analysis. Subjects with high homocysteine (tHcy) had lower Stroop scores than subjects with normal tHcy (P<.05). No biochemical parameters were associated with the Mattis Dementia Rating Scale scores. Conclusion: This study indicates that, in normal elderly subjects, some cognitive scores are related to serum methylcitric acid and possibly homocysteine. [source] Methodological considerations for measuring rates of brain atrophyJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2003Jeffrey L. Gunter PhD Abstract Purpose To systematically compare two techniques for measuring brain atrophy rates from serial magnetic resonance imaging (MRI) studies. Materials and Methods Using the separation in atrophy rate between cohorts of cognitively normal elderly subjects and patients with Alzheimer's disease (AD) as the gold standard, we evaluated 1) different methods of computing volume change; 2) different methods for steps in image preprocessing,intensity normalization, alignment mask used, and bias field correction; 3) the effect of MRI acquisition hardware changes; and 4) the sensitivity of the method to variations in initial manual volume editing. For each of the preceding evaluations, measurements of whole-brain and ventricular atrophy rates were calculated. Results In general, greater separation between the clinical groups was seen with ventricular rather than whole-brain measures. Surprisingly, neither the use of bias field correction nor a major hardware change between the scan pairs affected group separation. Conclusion Atrophy rate measurements from serial MRI are candidates for use as surrogate markers of disease progression in AD and other dementing neurodegenerative disorders. The final method has excellent precision and accurately captures the expected biology of AD,arguably the two most important features if this technique is to be used as a biomarker of disease progression. J. Magn. Reson. Imaging 2003;18:16,24. © 2003 Wiley-Liss, Inc. [source] | ||||||||||