Vascular dementia as a frontal subcortical system dysfunction.

Vascular dementia (VaD) is the second most common subtype of dementia in Western countries (Desmond, 1996) and, overall, may be the most common subtype of dementia in the world (Henderson, 1994). Furthermore, the recognition of some major risk factors of cerebrovascular disease makes VaD a form of ‘preventable senility ’ (Hachinski, 1992). The last decade has seen a major re-evaluation of the concept of VaD (Erkinjuntti & Hachinski, 1993; Hachinski, 1994), with new diagnostic criteria having been proposed (World Health Organization, 1993; American Psychiatric Association, 1994) but without any consensus (Wetterling et al. 1996). Indeed, some investigators have called for the abandonment of the diagnosis of VaD and the adoption of alternative nosology (Hachinski, 1994). It is therefore time to re-examine the concept of VaD and evaluate its distinctive features.