Unfortunately...there's so much we do not understand about this horrendous disease.
Three persons very close to me have Alzheimer's. My own Mom is in the 10th year...MIL passed this past Christmas, and FIL is in the 4th year. All were placed in different facilities...and that alone has helped me survive!
The progression has been entirely different with each one...and even obvious in the other "clients" where they now reside. Alzheimer's is very individual in how it affects each person. In the beginning of this journey with Mom, I read everything I could about this disease.
One thing that I remember is that "familial" (hereditary) Alzheimer's usually progresses more quickly than if this disease is caused by a very hard head injury. (This scares ME...I've had 2 hard bumps in the last 3 years...ARGH!) Also, any change in the persons surroundings or health, (even a cold!) can cause this disease to accelorate!
Research, research, research! Knowing what we can about this journey surely doesn't make it any easier...but at least helps us understand.
Each of us who post here understands your worry about "taking it's toll on YOU!"...... Be careful my friend, it has surely taken it's toll on my health, family, marriage, and outlook.................Pam