Sex differences in aging of the human frontal and temporal lobes

Abstract

This study investigated effects of age and sex on regional brain structure in humans, focusing on the frontal and temporal lobes. Hemispheric volumes were obtained from magnetic resonance images (MRIs) of 96 young (53 men, 43 women; aged 18-40 years) and 34 older (17 men, 17 women; aged 41-80) healthy volunteers. Images (5 mm axial spin-echo, repetition time of 3000 msec and echo times of 30 and 80 msec) were resliced along the anterior commissure-posterior commissure (AC-PC) axis to standardize for difference in head tilt, and imported into a computer program where borders of the frontal and temporal lobes were delineated. The program calculated regional brain volumes based on slice data from which CSF was segmented out. An age x sex x hemisphere x region interaction indicated that age-related reductions in brain volume were sexually dimorphic, lateralized, and region specific. Greater decrements in brain volume occurred with age in the frontal lobe than in the temporal lobe. Age-related reductions in both regions were greater in men than in women, demonstrating that sexual dimorphisms in human neuroanatomy are not fixed, but continue to change throughout adulthood. The possibility that gonadal hormones play a role in the promotion and/or prevention of neural atrophy with aging is discussed.

Age Effects in Identifying and Localising Dichotic Stimuli: A Corpus Callosum Deficit

“…Indeed, fMRI research had demonstrated that dichotic listening involves activation not only of temporal areas but also of frontal areas (Jancke & Shah, 2002). Further, it has been found that the frontal lobes in particular are most susceptible to age-related brain changes (Coffey et al, 1992;Cowell et al, 1994). Age-related asymmetry might therefore be stronger in dichotic listening tasks involving increased control of attention processes as is the case in our focussed attention conditions.…”

The Impact of Sex and Vascular Risk Factors on Brain Tissue Changes with Aging: Magnetization Transfer Imaging Results of the Austrian Stroke Prevention Study

“…This finding suggests a more rapid loss of normal white matter with aging in men. While it could be speculated that more pronounced atrophy of gray matter structures may have contributed to this finding, this is unlikely (ie, greater loss of gray matter-which has been reported by some to occur in men [30][31][32] -should have left the peak height unaffected rather than caused a decrease because of the increasing relative contribution of the white matter compartment in such a scenario). A recent study using multifrequency MR elastography, which reported a more preserved viscoelasticity of the brain with aging in women than men, is in line with our findings.…”

Detecting the significance of changes in performance on the Stroop Color-Word Test, Rey's Verbal Learning Test, and the Letter Digit Substitution Test: The regression-based change approach

“…Of interest, this interaction was not expected because most longitudinal studies report either no differences in the age-related decline in cognitive functions for men and women (Aartsen et al, 2004), or, when gender differences are observed, a more pronounced decline for females (Meinz & Salthouse, 1998). However, volumetric imaging studies have shown a stronger effect of aging on the frontal lobes in men than in women (Cowell et al, 1994;Murphy et al, 1996). This finding may explain the age 3 gender interaction found for the SCWT Interference change score.…”