CT in the differential diagnosis between Alzheimer's disease and vascular dementia.

A prospective series of consecutively admitted patients with Alzheimer's disease (AD) (n = 68), multi-infarct dementia (MID) (n = 79) and probable vascular dementia (PVD) (n = 46) were studied by CT of the head. In MID 88.6% and in PVD 41.3% of the patients had at least one brain infarct on CT, but only one patient (1.5%) with AD. White matter low attenuation (WMLA) also differentiated MID and PVD from AD, especially among patients aged 75 years or less, and with mild or moderate dementia. In all types, brain atrophy on CT had a positive correlation with the degree of dementia. Infarcts and WMLA on CT, but not brain atrophy seem to be of differential diagnostic value between vascular and degenerative dementia.