Differences in regional cerebral blood flow patterns in male versus female patients with Alzheimer disease

Abstract

Background and purpose: There may be some differences in the pathophysiology between men and women with Alzheimer disease (AD). This study was undertaken to explore the possible influence of sex on regional cerebral blood flow (rCBF) patterns in patients with AD.

Methods: Single photon emission CT (SPECT) was performed in 30 men and 30 women with AD, and the SPECT data were analyzed by using 3D stereotactic surface projections.

Results: There were no significant differences in age, duration of disease, years of education, cognitive deficits and patterns, and MR imaging findings (grade of brain atrophy and extent of white matter hyperintensity lesions) between the two groups. Both male and female patient groups showed decreased rCBF patterns in the parietotemporal lobe, posterior cingulate cortex, and precuneus, which are considered to be the characteristic SPECT findings of AD. There were, however, some differences in rCBF patterns: men had a more severe decrease of rCBF in the parietal and posterior cingulate cortex, whereas women had a more severe decrease of rCBF in the medial temporal region and frontal lobe.

Conclusion: These data provide evidence that patterns of rCBF deficits differ between the sexes, a finding that supports the concept of heterogeneity of the underlying pathophysiology of AD.

Fig 1.

Statistical maps showing the relative decrease of rCBF in men with AD compared with that in control subjects (top) and in women with AD compared with that in control subjects (bottom). Although both patient groups show a notable decrease of rCBF in the parietotemporal lobes, posterior cingulate cortex, cinguloparietal transitional area, and frontal association cortices, men have a more severe reduction of rCBF in the parietal lobe and posterior cingulate cortex, and women have reduced rCBF in additional areas, including the frontal lobe and medial temporal regions. The color of the outer contour corresponds to a Z score of 7.

Fig 2.

Statistical maps showing the relative decrease of rCBF in men with AD compared with that in women with AD (top) and in women with AD compared with that in men with AD (bottom). Men have a more severe decrease of rCBF in the parietooccipital and medial parietal lobes, whereas women have a more severe decrease of rCBF in the lateral, medial and orbital frontal lobes, and medial and inferior temporal regions. The color of the outer contour corresponds to a Z score of 7.