My wife's grandmother/aka/mother had it...took her 9 years to die from it....9 very long years during which she knew no one. Death was a blessing for her and the family.
You have my sympathy...been there done that. Praying for you and your family.
My mother had it the last 3 years of her life. We could see her slipping away more and more every day. God intervened when her leg broke at age 87. Seven weeks later she passed away. It was a sad but happy day in our lives. She was relieved of her illness and was at peace.