Controversies in vascular dementia

The main controversies in the field of vascular dementia (VaD) include the nosological classification of this disorder, the definition of dementia, the differences between the different sets of diagnostic criteria, the concept of Binswanger disease, the role of vascular lesions in Alzheimer disease, and the results of cholinesterase trials in VaD. Vascular Cognitive Disorder (VCD) is the most current nosological classification for the global diagnostic category of cognitive impairment of vascular origin, ranging from mild cognitive impairment (MCI) to vascular dementia. It includes specific disease entities such as poststroke VaD, CADASIL, Binswanger disease, and AD plus CVD. Vascular cognitive impairment (VCI) is limited to cases of vascular MCI without dementia, by analogy with the concept of amnesic MCI, currently considered the earliest clinically diagnosable stage of Alzheimer disease (AD). The main problem of VaD stems from the currently accepted definition of dementia that requires memory loss as the sine qua non for the diagnosis. This may result in over-sampling of patients with AD worsened by stroke (AD+CVD). We have proposed an operational definition of dementia in VaD based on the presence of abnormal executive control function, severe enough to interfere with social or occupational functioning. This may increase the sensitivity and specificity of the NINDS-AIREIN criteria. In donepezil trials in VaD that excluded prestroke MCI, the placebo groups were different from those in AD without CVD, and in AD+CVD trials.