My 90-year-old mother recently became "unresponsive" for 40 minutes. The doctor said it was due to a UTI. Is this common?

She lives in a NH and the nurse called me the other night to say they had called an ambulance. She said my mother had been fine during dinner then during Bingo but when they went to wheel her back to her room, they found her slumped over in her wheelchair like she was asleep. They tried to wake her up, but she wouldn't respond at all. Her body was completely limp and her eyes were shut. They took her vitals, which were fine.

My immediate thought was stroke. When I got to the ER the EMTs said she had stirred a little on the way to the hospital, but was still pretty incoherent. She started vomiting in the ER, which is unusual for her. They ran tests and a CT scan didn't show any bleeding on the brain. The neurologist examined her and thought that a stroke was unlikely. She had more tests yesterday and the only thing they found was a UTI. She's been getting frequent UTIs over the years, but never had a reaction to one like this. I know UTIs in the elderly can present as a sudden behavioral or personality change but I didn't know they could cause a patient to become totally unresponsive like that.

She seemed a little (a very little) more coherent when I visited yesterday and they said they'd be keeping her there for a few days. She's being treated with an IV antibiotic.

Has anyone had a loved one have this reaction to a UTI?