Well, the way that you describe the symptoms sound like it could possibly be a seizure. This can cause eye rolling back in the head, loss of consciousness and then disorientation or confusion after the event. The person can feel quite tired afterwards as well. Seizures can be temporal, meaning that they may happen at certain times of the day more than others.
It is hard to say that is what is going on without knowing her, but that would be a concern.
Elderly people also can get disoriented at night if they are in an unfamiliar place. This is called sundowning. this would not cause the eye rolling or loss of consciousness though.
Medications (especially for sleep, like ambien/zolpidem
) can cause strange behaviors at night, so if she is on them, it could be related to that.
I would definitely discuss this with her doctor, if you are in a position to do so. It is not a normal thing for an elderly person to do.
If you have any more questions, please ask.