Role of functional brain imaging in the evaluation of vascular dementia

There are various types of underlying damage to tissue and vessels in vascu lar dementia, including (1) single or multiple infarcts that involve associ ation and limbic cortices, (2) small subcortical infarcts disrupting cortic o-subcortical circuits, and (3) white matter lesions. The clinical picture of vascular dementia varies, and the role of functional brain imaging of ce rebral blood flow and metabolism would be expected to be different among su btypes of vascular dementia. The role and value of functional brain imaging is limited for cortical infarcts; it is very valuable in assessing the imp act on cortical function for small subcortical infarcts; and it is probably useful for evaluating white matter lesions, but this needs to be determine d in further studies. At least in research of vascular dementia, functional brain imaging criteria should be included for proper patient selection. Ca reful studies using functional imaging tools in a well-characterized patien t population will be needed.