Does cerebrovascular insufficiency contribute to Alzheimer's disease?

The differential diagnosis of vascular dementia (VD) and Alzheimer's disease (AD) based on clinical assessment and neuropsychologic testing is still associated with a relatively high degree of inaccuracy compared to neuropathology standards. This is especially true in the identification of mixed forms between AD and VD. The present study investigates the potential of neuroimaging methods in providing additional information in dealing with this problem. Magnetic resonance imaging (MRI) of the brain identified a relatively high percentage (39%) of patients with AD (with ischemia scores of 4 and less) with basal ganglia hyperintensities and also demonstrated basal ganglia lacunae and infarcts in some of these patients. These findings indicate that in these cases a vascular component, consistent with the mixed form of dementia, may contribute to the etiology of the disease. These findings also underscore the clinical usefulness of MRI in the further differentiation of the dementias.