Vascular dementia: a radical redefinition.

'Vascular dementia' may be the leading cause of cognitive impairment in the world, yet there is little agreement as to what this concept encompasses or how it is defined. A critical review reaches the conclusion that the concept of 'vascular dementia' has become obsolete. 'Vascular' is too generic, and fails to identify specific etiologies which may be subject to current and future preventive measures. 'Dementia' identifies patients too late to do much about their problem. An alternate approach is suggested. Identify patients across the whole spectrum of vascular cognitive impairment, from high risk with no deficit ('brain-at-risk stage') to full-blown dementia. Describe the cognitive impairment in terms of standardized neuropsychological measures, and relate the dementia to the specific vascular cause, so that the appropriate preventive measures can be implemented.