I saw strong signs of vascular dementia, and given his history of AFib it was likely. Watching him trip on flat surfaces, blank stares ending with "well I better not" or "Anyway" and veer off into a new subject, stand there blankly during actual photo ops when he was supposed to be clapping and dancing. Unable to actually follow simple directions like the one where the SS agent told him to turn down a path and he just kept walking following the guy... watching him shake hands with nobody, having to have taped X's where he was supposed to stand and incapable of speaking without crotch notes... constantly telling stories about the conversations he just had with dead people, making up memories like his Uncle being eaten by cannibals...