Has anyone experienced sudden unexplained unresponsiveness in the elderly? Not responsive to pain, noise, nothing. Then suddenly they just wake up?

I was going to suggest seizures as well, I have read that sometimes they are associated with Alzheimer's and some other types of dementia.

https://www.verywellhealth.com/alzheimers-disease-causes-of-seizures-1204507

duplicate

I would wonder about seizures. We were told by a doctor once that a seizure needs to be observed in order to be diagnosed. Can you ask the neurologist about that?