Alzheimer's or Dementia? What could this be?

My dad had a stroke 6 years ago and a broken L3 vertebrae.  He started having these episodes about 2 months ago.  He is normal for about a week and then on day one he is a little confused...thinks he see's a mouse, thinking someone was in the room but they weren't, want's to eat & has has a stomach tube for 6 years and can have nothing by mouth, etc.  On the second day it is alot worse...he tries to walk without his walker & falls, want to take the car for a ride, tries to go up the stairs, goes and gets food out of the cabinet, thinks things that happened years ago just happened, etc.  He never forgets who anyone is though.  On the 3rd or 4th day he is similar to the first day & then starts to jerk (not like a seizure) expecially when asleep.  He has had numerous EEG's and they are all normal - not seizure activity.  He will jerk his head/upper body about twice a minute.  He then sleeps for pretty much a whole day.  Then he is back to normal again for about a week or so when the whole thing starts all over again.  He has has blood work - normal, blood gas test- normal, taken off a couple of medicines.  Nothing has helped and the doctors have not idea what it is caused from.  Please help...what could be happening to my dad?

[caregiver222]

Alzheimer's is a form of dementia.

Generally dementia is classified into two categories. Alzheimer's and non-Alzheimer's.

Non-Alzheimer's dementia can be due to many different things, from a prion infection to a retrovirus infection (HERV-W) to ischemia.

Drugs, specifically Lipitor and the statins can also induce dementia because cholesterol is necessary to formulate memory.

You really need a neurologist and an in-person examination to provide you with the answers you seek.