While it's not generally prescribed in the UK for anything but Alzheimers, it is used in other countries for people with other types of dementia. There have been several studies done that showed improved function in people with vascular dementia who were treated with aricept. Unfortunately, the last one also showed an increase in deaths. However, there is some evidence that this result was skewed by an abnormally low (i.e. 0) death rate in the group NOT receiving the drug, because the actual death rate in the group receiving Aricept was in line with previous studies. So it's definitely effective, and the jury's still out on whether it is safe. So, just because you have responded to aricept does not mean that you have AZ. Just make sure (obviously) that you carry on doing whatever you're doing to reduce your chances of future strokes etc.
Jennifer