My father was diagnosed with vascular dementia. He went fast. I recall he fell a couple of times. It wasn't because he was dizzy or tripped, he said that his legs just wouldn't support him - they just gave out on him. It was extremely intermittent. I wish I would have known that was a symptom of dementia (among other things) but I didn't realize it.

My father had a few small strokes, he did not realize it at the time and I didn't realize it until I went to the doctor's visit with him. His brain went fairly quickly after that but at least he had the wherewithal to give me his car keys and try to at least maintain his muscle strength.

It is difficult. There is nothing you can really do about it except make them comfortable. My father was basically a gentle soul but he would get scared because he had the hallucinations at times. It doesn't really get any easier, at least n my experience and with people with whom I have spoken about this topic.