We are taking care of my mother in law; but it seems that it is moving way too fast. One month ago she was going through the sun downers stage; but now she can hardly walk without assistance and we are having her use depends because she can not control her bladder. She also will not eat and drink as much as she should. Her Neurologist appointment is this Monday. Two months ago she was fine. This seemed like it came out of nowhere. How fast can the progression be with this disease?