My grandfather died from vascular dementia (its a less common form of dementia then Alzheimer and can even be worse)
At the end i was visiting him in the hospital where he was staying and he looked at me and asked, who is this man?
I am familiar with vascular dementia. It has reared its ugly head with one member of the family now although it’s not gotten too bad yet. My grandfather (back in the ‘60s) got really bad, although at that time, just about everything was diagnosed as “hardening of the arteries”, but I’m sure (with 20/20 hindsight) vascular dementia is what he had.
It is heartbreaking when those you love & who have loved you, get to the point where they don’t know you any more. My dad’s sister, a really dear aunt with whom I had a fairly close relationship, several years ago when we went to visit her, asked my folks “who is that woman you brought with you?” They told her who I was and she didn’t really react to it and ignored me during the visit. Fortunately for my memories of her, the last time we visited, she wanted to hold my hand and was really sweet and talked to me - I had to tell her who I was and for a precious few minutes, she seemed able to hold on to the fact that we were related. It was a really good last visit - we saw her in May & she died the day after Thanksgiving.