Correlation of White Matter Lesions, Cerebral Blood Flow, and Cognitive Decline in Patients With Alzheimer’s Disease and Vascular Dementia

Objective This study investigated the relationship between white matter lesions (WMLs), cerebral blood flow (CBF), and cognitive decline in a mixed cohort of patients diagnosed with Alzheimer’s disease (AD) and vascular dementia (VaD). Method This cross-sectional study included 100 patients with AD or VaD (ages 55–85) and 50 age- and education-matched healthy controls. Participants underwent neuroimaging and cognitive assessment. Volumetric WMLs were quantified using FLAIR MRI, and CBF was measured with arterial spin labeling MRI. Cognitive function was evaluated using the Alzheimer’s Disease Assessment Scale–Cognitive Subscale (ADAS-Cog). Structural atrophy was also visually rated, and biochemical markers were analyzed. Results Compared to controls, the AD/VaD patient group had a significantly higher WML volume (p < .001), reduced global CBF (p < .001), greater brain atrophy, and worse ADAS-Cog scores (p < .001). A hierarchical multiple linear regression analysis in the patient group revealed that WML volume (β = 0.55, p < .001) and global CBF (β = −0.38, p < .001) were significant independent predictors of ADAS-Cog scores after controlling for age, education, and brain atrophy. Brain atrophy itself was also a significant predictor (β = 0.21, p = .005). The model explained 72% of the variance in cognitive scores. Conclusions In a clinically mixed dementia cohort, the burden of WMLs and the magnitude of CBF reduction are strongly associated with the severity of cognitive impairment. These findings highlight the critical contribution of cerebrovascular pathology to cognitive dysfunction and underscore the value of quantitative imaging markers in understanding dementia’s neurobiological substrates.