valium and alzheimers

My husband is diagnosed with MCI due to early Alzheimer's. He recently took 1 valium before an MRI because he gets claustrophobic in that enclosed space. The next day he became terribly confused not knowing I was his wife and thinking our house was not his home. This is just bizarre, almost like a nightmare. His doctor said it was probably from the valium and also the fact that we went out of town the next day and he became confused as to where he lived. My husband has memory issues and confusion due to the memory problems, but he is still driving locally, going golfing, etc. This is like someone flipped a switch. Has anyone else experienced something happen like this if the person you care for had a valium? Will this get better? It's been slightly over a week and some parts of the day are fine, but others are not. Thank you for your help.