My father has vascular dementia. Just recently he has begun complaining of 'jitters'. He says he feels 'jittery'. However, when he says he is feeling this way he does not appear to be shaking. He responds to speech and moves more slowly. He may stop talking and tilt his head down just slightly like he's staring intently at something but he doesn't seem to see anything. It's just for a split moment and only at times when he complains about a jittery feeling. Has anyone seen anything like this?