Although cerebrovascular diseases are the most common causes of dement
ia after Alzheimer's disease, vascular dementia (VD) has remained so f
ar an ill-defined term. The main problems in the definition of VD aris
e from finding criteria for both terms ''vascular'' and ''dementia''.
The detailed criteria for the diagnosis of VD proposed by several grou
ps or institutions (ADDTC, DSM-IV, ICD-10, NINDS-ARIEN) are critically
reviewed. The diagnostic value of some clinical findings, especially
the very frequent white matter luciencies in CT (leuko-araiosis), are
discussed. The available studies suggest a differentiation of VD into
some subtypes (listed according to the frequency): subcortical VD, VD
with acute onset, multiinfarct-elementia, mixed types, and specific fo
rms. Nevertheless, these subtypes give only little information about t
he etiology of the underlying vascular process and, therefore, no clea
r indication for specific therapeutic strategies.