Suggest Treatment For Shingles And Deliriousness

Question : My Dad is 85 years old. He got shingles and was feeling and acting ok until he went to the hospital. After a few days in the hospital, he started getting delirious and his speech comes and goes. He also cant swallow so he is getting infections which keep coming back after antibiotics are done. All his tests such as heart , blood pressure, EEG, MRI, come back good. His doctors are saying its a mystery and they cant figure out what is wrong. One neurologist mention a possible undetected stroke in the Pons area could be possible. My Dad seems to me to have had a stroke. He is also agitated and thrashes around until they give him Adivan (I think that's what it is called) which calms him down. When asked where he is, he gives them a city that he lived in years ago, but he is consistent about that. He kindof recognizes me (his son). Any ideas about what to try would be greatly appreciated. His doctors have given up, and he was fine 6 weeks ago.

I will try toget his records today and send them