You seem to think dementia is just a loss of memory.
More accurately I think that it is a physical handical that prevents us from being all that we can be. It is my opinion. I may be wrong however at this time my guess is as good as anyone elses.
Nop, your guess is certainly not as good as anyone elses. There are people studying in that specific field, and their guess far outweight yours.
In fact, they don't really toss a coin, they don't guess, they deduce.
My 2 cents