Abstract
Many evidences suggested a coexistence of vascular lesions in Alzheimer’s disease (AD), although there had been a dichotomy between AD and vascular dementia (VaD) in the clinical diagnosis of dementias. To clarify the hemodynamic correlates of the vascular risk factors in AD and VaD patients, we investigated the relationship between the cerebral blood flow (CBF) images provided by SPECT and vascular risk factors. The present study was based on 157 patients with probable VaD and 59 patients with probable AD. On the CBF images, 122 (77.7%) of 157 VaD patients showed a hypoperfusion in the frontal lobe and 114 patients (72.6%) showed a hypoperfusion in the parieto-temporal region. All AD patients underwent laboratory testings, neuropsychological evaluation, MRI and 99mTc ECD SPECT. Based on the existence of the white matter hyperintensity (WMH) and/or subcortical infarction on MRI, all patients were classified into 2 categories: those without WMH (Group A) and those with WMH (Group B). MMSE scores negatively correlated with patients’ age, BNP, and HOMA-R. Statistical parametric mapping (SPM) revealed a significant hypoperfusion in the frontal lobe in Group A as compared with Group B. Those with greater BNP showed a significant hypoperfusion in the anterior cingulate gyri and superior frontal gyri as compared with those with smaller BNP. As compared with those with smaller HOMA-R, those with greater HOMA-R showed a significant hypoperfusion in the anterior cingulate gyri and frontal lobe. The frontal hypoperfusion which was associated with vascular risk factors might modify the hemodynamic pathophysiology in AD patients.
