I have just had exactly the same problem with my mum just before Christmas. She was taken into hospital suffering dt's. She didn't know my name, thought that it was 1924 etc, the usual stuff that I have read about. I was having to give her step by step instructions on how to use the toilet. She was taken in an ambulance on the friday, they sent her home and we took her back in Sunday as she had been in the park all night hallucinating her dog, which I was looking after, in the frost with no shoes on.
Anyway, she was in 10 days. Although she was a lot better, she is still not totally right but she is 73 and had alcoholism for about 14 years without a break so it was obviously going to take time.
The sad thing is that she sits and laughs about it, has no remorse whatsoever and is drinking again. I have given up, life is too short to worry about someone that doesn't care for either herself or me and I have a life to live.
Good luck with your mum and try not to worry, loads of people get dt's and come through it fine.