From what I've read this is a result of very high blood sugars and dehydration.
My grandmother had a problem with the dehydration part too with her diabetes. It didn't help that she drank coffee throughout the day. We had to get her to drink water and other things in order to maintain her levels. It wasn't easy. She was in her 80's and very stuck on her way of doing things. When it was my turn to be with her, I would drink water with her since my body has issue with fluids. She was better at doing that then instead of being combative.
They say once you are thirsty your body is already dehydrated. Encourage your mom to get fluids in, preferably not sugared drinks. My aunt bought a ton of these for my grandma and I thought I was going to have to go crazy on her. I didn't. Just told my grandma not to drink those.
Keep us posted. It can be very difficult to be far away and have this happen.