Effect of white matter lesions on brain perfusion in Alzheimer's disease.

Background: This study examined the effect of white matter lesions (WMLs) on regional cerebral blood flow (rCBF) in patients with Alzheimer's disease (AD).

Methods: Ninety-eight patients with AD were included in the study (40 men and 58 women; mean age, 78.1 years). Cognitive function was assessed using the Mini-Mental State Examination. Brain magnetic resonance imaging (MRI) and (99m)Tc ethyl cysteinate dimer single photon emission computed tomography were performed in all subjects. AD patients were divided into two subgroups according to the presence of WMLs on MRI. A voxel-by-voxel group analysis using Statistical Parametric Mapping 8 was used to detect the differences in rCBF between the two groups.

Results: Fifty-seven of 98 AD patients (58%) showed mild to moderate WMLs on MRI. The prevalence of hypertension was significantly higher in AD patients with WMLs than in those without WMLs. AD patients with WMLs exhibited a significantly decreased rCBF in the anterior cingulate gyrus and insula, compared to AD patients without WMLs.

Conclusion: We suggest that WMLs might influence brain regions associated with the limbic system in patients with AD.