Showing papers by "Charles DeCarli published in 1992"

Method for quantification of brain, ventricular, and subarachnoid CSF volumes from MR images.

Abstract: We describe a simple, rapid, and semiautomated method of MR analysis based on mathematical modeling of MR pixel intensity histograms. The method is shown to be accurate and reliable for regional analysis of brain, central, and subarachnoid CSF volumes. Application of the method to five young and six older subjects revealed significant age-related changes in regional brain volumes whereas no difference was found for traced central CSF volumes or subarachnoid CSF volumes. We conclude that this is a simple method that can be applied to further studies of quantification of brain structure in healthy aging and brain disease.

Age-related differences in volumes of subcortical nuclei, brain matter, and cerebrospinal fluid in healthy men as measured with magnetic resonance imaging

Abstract: • Magnetic resonance imaging was used to determine the volumes of brain, subcortical gray matter nuclei, and the ventricular and sulcal cerebrospinal fluid in 27 healthy men. Subjects were divided into young ( 60 years, n= 17) groups. Volumes were normalized as percent intracranial volume. Older subjects had significantly less brain mass and significantly larger ventricular and peripheral cerebrospinal fluid volumes than the younger men. The caudate and lenticular nuclei were significantly smaller in older than younger men. This significant difference remained when their volumes were expressed as a ratio of cerebral brain matter volume. This cross-sectional study demonstrates age-related atrophy and concurrent dilation of cerebrospinal fluid spaces in healthy subjects. Of brain regions affected, the caudate and lenticular nuclei are significantly more affected by healthy aging than is cerebral brain matter; this may account for some of the motor abnormalities in aging.

Brain atrophy in hypertension. A volumetric magnetic resonance imaging study.

Abstract: To determine whether hypertension, the predominant risk factor for stroke and vascular dementia, is associated with brain atrophy, magnetic resonance imaging (MRI) scans were performed to quantify brain volumes and cerebrospinal fluid spaces. Eighteen otherwise healthy, cognitively normal older hypertensive men (mean +/- SD age, 69 +/- 8 years, duration of hypertension 10-35 years) and 17 age-matched healthy, normotensive male control subjects were studied in a cross-sectional design. Axial proton-density image slices were analyzed using region-of-interest and segmentation analyses. The hypertensive subjects had significantly larger mean volumes of the right and left lateral ventricles (p less than 0.05, both absolute volume and volume normalized to intracranial volume) and a significantly smaller normalized mean left hemisphere brain volume (p less than 0.05) with a trend toward significance for a smaller normalized mean right hemisphere volume (p less than 0.09). Four hypertensive subjects and one healthy control subject were found to have severe periventricular hyperintensities on T2-weighted MRI images. When data for these subjects were removed from the analyses, the normalized lateral ventricle volumes remained significantly larger in the hypertensive group. Lateral ventricle enlargement was not related to age or use of diuretics in the hypertensive group nor to duration of hypertension between 10 and 24 years. Our findings suggest that long-standing hypertension results in structural changes in the brain. Longitudinal studies will determine whether MRI-associated changes are progressive and if such changes identify hypertensive subjects at increased risk for clinically apparent brain dysfunction.

Longitudinal changes in lateral ventricular volume in patients with dementia of the Alzheimer type.

Abstract: We determined the rates of lateral ventricular enlargement and decline in cognitive performance for 11 men and nine women with dementia of the Alzheimer type (DAT), and compared these rates with the same measures obtained for age-matched healthy controls (nine men and eight women). DAT patients, as a group, had only mild cognitive impairment at initial evaluation, and each patient was followed from 9 months to over 7 years with yearly evaluations. Six DAT patients had isolated memory impairment as their only cognitive deficit early in the course of the disease. The rate of total lateral ventricle enlargement (cm3/yr) was significantly different between DAT and healthy controls, and was more specific and sensitive to the diagnosis of DAT than comparison of cross-sectional volumes at final evaluation. The rate of total lateral ventricular enlargement did not differ significantly by patient sex, ventricular size at initial evaluation, age, or degree of cognitive impairment as measured by Mini Mental State Examination scores. However, in the six DAT patients initially found to have isolated memory impairment, the rate of ventricular enlargement during the period of isolated memory impairment was significantly less than the rate of ventricular enlargement after the onset of nonmemory cognitive impairment. The diagnostic power of total lateral ventricular measures made from two CTs separated by 1 year and obtained early in the course of the illness, however, was only 0.33. We conclude that the total lateral ventricular enlargement accompanying DAT is due to continuous, pathologic cell loss, significantly greater than cell loss due to the healthy aging process.(ABSTRACT TRUNCATED AT 250 WORDS)

The significance of age-related enlargement of the cerebral ventricles in healthy men and women measured by quantitative computed X-ray tomography.

Abstract: Objective (1) To establish the range of cerebral atrophy across the adult age spectrum in optimally healthy, rigorously evaluated individuals. (2) To determine, across the age spectrum, the relation of gender and cerebral atrophy (as measured by ventricular enlargement) to cognitive function. Design Cross-sectional comparison by age and gender. Setting Ambulatory research unit. Participants Sixty-four healthy men (mean age +/- SD = 49 +/- 18 yr) and 43 healthy women (51 +/- 18 yr) volunteers enrolled in a longitudinal study of healthy aging. The population was selected for optimal health; all were rigorously screened to exclude medical and psychiatric illness. Main outcome measures Brain atrophy by CT scan and cognitive function by standardized neuropsychological testing. Results After correction for inter-subject variability in cranial volume, women had smaller lateral, but not third, ventricles. For both genders, there were significant differences with age in ventricular volume. After an approximately constant 20% increase in ventricular volume per decade in both genders, a precipitous increase in volume was found beginning in the fifth decade in men and in the sixth decade in women. In men and women, there was a significant negative correlation between ventricular volume and the sum of performance scale scores on the Wechsler Adult Intelligence Scale (WPSS) but not in the sum of the verbal scale scores (WVSS). However, after controlling for age, ventricular volume no longer significantly contributed to the relation between age and WPSS. Conclusions In unequivocally healthy individuals, gender plays an important role in age-associated central cerebral atrophy as measured by progressive ventricular enlargement. Increase in ventricle volume independent of age, does not explain normal age-related declines seen in WPSS scores.