I'm sorry for your poor grandmother, and the family. I know how hard this is for you.
I learned, while taking care of my mother, that anything different from her normal routine would throw her off. In my fourth year with her, she'd gotten out of bed at some point, and ended up sitting on the floor at the side of her bed. I found her at 7:00 when I went in to get her dressed. She was in the hospital several days, and at first she kept her eyes closed, and didn't talk at all, and when she finally did, it was in a little girl's voice. She acted like she didn't know what the food they brought her was for, but when I'd hold a spoonful up to her, she'd open her mouth and take it. She remained "off" like that until after they'd sent her to the nursing home to get her back on her feet. When I finally took her home, she was as she'd been before this all happened.
She liked to go for rides with me, and she enjoyed people visiting. But most visitors were strangers to her, and even though she enjoyed them, and the rides, once everything was back to normal, she'd get really weird for a few days.
What your grandmother went through would be traumatic for any of us, but to her, because of age and the disease, it's even more so, and she'll react to it. If she's still in her own home, even with the 24 hour care, I believe she'll be her old self before too long. Best wishes for her, and you.