Background: Our objectives were to compare the effects of subcortical ischemic vascular dementia (SIVD) and Alzheimer's disease (AD) on cerebral blood flow (CBF), and then to analyze the relationship between CBF and subcortical vascular disease, measured as volume of white-matter lesions (WMLs).
Methods: Eight mildly demented patients with SIVD (mean +/- SD; aged 77 +/- 8 years; Mini-Mental State Examination score 26 +/- 3 years) and 14 patients with AD were compared with 18 cognitively normal elderly subjects. All subjects had CBF measured using arterial spin-labeling magnetic resonance imaging, and brain volumes were assessed using structural magnetic resonance imaging.
Results: AD and SIVD showed marked CBF reductions in the frontal (P = 0.001) and parietal (P = 0.001) cortices. In SIVD, increased subcortical WMLs were associated with reduced CBF in the frontal cortex (P = 0.04), in addition to cortical atrophy (frontal, P = 0.05; parietal, P = 0.03).
Conclusions: Subcortical vascular disease is associated with reduced CBF in the cortex, irrespective of brain atrophy.