@article {1495, title = {Sex differences in brain aging: a quantitative magnetic resonance imaging study.}, journal = {Arch Neurol}, volume = {55}, year = {1998}, month = {1998 Feb}, pages = {169-79}, abstract = {

BACKGROUND: Little is known about the effect of sex on age-related changes in brain structure.

METHODS: Quantitative magnetic resonance imaging of the brain was performed in 330 elderly (age range, 66-96 years) volunteers living independently in the community, all of whom were participants in the Cardiovascular Health Study. Blinded measurements of global and regional brain size were made from T1-weighted axial images by means of computer-assisted edge detection and trace methods. High measurement reliabilities were obtained.

RESULTS: Age-specific changes in brain size were significantly greater in men than women for the peripheral (sulcal) cerebrospinal fluid volume, the lateral (sylvian) fissure cerebrospinal fluid volume, and the parieto-occipital region area. Main effects of age were observed for all the remaining brain regions examined (cerebral hemisphere volume, frontal region area, temporoparietal region area, lateral ventricular volume, and third ventricle volume), but these effects were similar in men and women. Asymmetries in brain structures were not affected by aging in either sex.

CONCLUSIONS: Our results are generally consistent with the few published studies on sex differences in brain aging and suggest that, for at least some structures, aging effects may be more apparent in men than women. The neurobiological bases and functional correlates of these sex differences require further investigation.

}, keywords = {Age Distribution, Aged, Aged, 80 and over, Aging, Atrophy, Brain, Cerebrospinal Fluid, Diagnosis, Computer-Assisted, Female, Health Status, Humans, Magnetic Resonance Imaging, Male, Regression Analysis, Sex Characteristics, Sex Distribution}, issn = {0003-9942}, author = {Coffey, C E and Lucke, J F and Saxton, J A and Ratcliff, G and Unitas, L J and Billig, B and Bryan, R N} } @article {598, title = {Relation of education to brain size in normal aging: implications for the reserve hypothesis.}, journal = {Neurology}, volume = {53}, year = {1999}, month = {1999 Jul 13}, pages = {189-96}, abstract = {

OBJECTIVE: To examine the relations between education and age-related changes in brain structure in a nonclinical sample of elderly adults.

BACKGROUND: Education may protect against cognitive decline in late life--an observation that has led to the "reserve" hypothesis of brain aging. Little is known, however, about the effect of education on age-related changes in brain structure.

METHODS: Quantitative MRI of the brain was performed in 320 elderly volunteers (age range, 66 to 90 years) living independently in the community (Mini-Mental State Examination scores > or =24), all of whom were participants in the Cardiovascular Health Study. Blinded measurements of global and regional brain size were made from T1-weighted axial images using computer-assisted edge detection and trace methodology. High measurement reliabilities were obtained.

RESULTS: Regression analyses (adjusting for the effects of intracranial size, sex, age, age-by-sex interactions, and potential confounders) revealed significant main effects of education on peripheral (sulcal) CSF volume-a marker of cortical atrophy. Each year of education was associated with an increase in peripheral CSF volume of 1.77 mL (p<0.03). As reported previously, main effects of age (but not education) were observed for all of the remaining brain regions examined, including cerebral hemisphere volume, frontal region area, temporoparietal region area, parieto-occipital region area, lateral (Sylvian) fissure volume, lateral ventricular volume, and third ventricle volume.

CONCLUSIONS: The authors{\textquoteright} findings demonstrate a relation between education and age-related cortical atrophy in a nonclinical sample of elderly persons, and are consistent with the reserve hypothesis as well as with a small number of brain imaging studies in patients with dementia. The neurobiological basis and functional correlates of this education effect require additional investigation.

}, keywords = {Aged, Aged, 80 and over, Atrophy, Brain, Cerebral Cortex, Cerebrospinal Fluid, Educational Status, Female, Functional Laterality, Health Status, Humans, Magnetic Resonance Imaging, Male, Mental Status Schedule, Regression Analysis, Sex Characteristics}, issn = {0028-3878}, doi = {10.1212/wnl.53.1.189}, author = {Coffey, C E and Saxton, J A and Ratcliff, G and Bryan, R N and Lucke, J F} }