How Long.

How long can a person have dementia for? Is it possible to have had a diagnosis twenty-two years ago and still seem to be almost normal?

I have heard of dementia patients living for 20years although believe it’s rare. I can’t say any one being almost normal? Only going on residents at my late husband’s nursing home, in that they all declined, some much more slowly than others.
Can you have a chat to the Alzheimer’s society?