What is vascular dementia?  

Caused by a stroke. Most people think of vascular dementia as memory and other brain impairments leading to dementia caused by one or more large strokes. There is another condition related to chronic small damage to the brain ultimately leading to dementia, this used to be called multi-infarct dementia though this phrase isn't used much anymore.
Vascular dementia. Is a different type of dementia caused by strokes or small vessel disease. This type of dementia causes a stepwise decline rather than a slow progression.
Confusion. It is confusion and loss of memory based on narrowing of the blood vessels in the brain.