Isn't the chance of heredity just 6%? It is probably infection as others have mentioned, since it came and passed 2 years ago.
With such a sudden onset, it does not sound like alzheimers or other forms of dementia. I would definitely get her checked out as it may be something totally unrelated to the brain. Many infections have that type of confusion effects, or side effect to a medication or something else environmental. You are in my thoughts and prayers.
It is odd the sudden onset. While I know this can happen there are usually signs of the confusion before where they were masking the problem. I would go to the doctor and have some labs done. A UTI (urinary tract infection) can cause increase confusion and balance issues for people in the older years (75+).
Good luck
Josh
I think the next step is getting your mom in to see her doctor. If you live a ways away and can't go with her to the doctor's appointment, I would call her doctor before she goes in for the appointment and tell him/her what happened that day. You probably will not be able to have a two-way conversation about your mom with the doctor or nurse (meaning, to ask questions about her condition or care) unless she has signed a release of information form because of strict medical privacy laws---BUT you are still allowed to call and tell them your concerns. This can be frustrating, I know....
What I have done in the past about both of my parents' health problems is called the doctor's office, asked for their FAX number, and then faxed a short note to the doctor's attention. I briefly state my concerns, what's happened, what we've observed, etc. I always thank them for their time and attention and for caring for my parent and give them my name and phone number in case they want/need to reach me. This has worked pretty well over the last 5-10 years.
I can understand your concerns about your mother, given your grandmother. I'm saying a prayer for you and your mother.
My father was diagnosed with probable dementia this year--It's a very hard situation and hard to imagine if you've not had a loved one go through it before. My heart goes out to you. Please let us know how things go.
Take care,
Yvette