First, Anne, I am so sorry to hear about your Father. I think if this were my Father I would make sure he has a full physical. There seems to be a difference between Dimentia and Alzheimer. And there are different stages. My Aunt takes medications which keep her from being constantly on the go...it's helping her rest more and not wearing her out.
Your dad sounds like something for certain isn't right and I hope your Mom gets him to someone who can figure out what's going on.
Aunt Mary's daughter is moving from Colorado back to Montgomery in a few months so she can help her dad with her mom. Uncle Norman is 86 (soon to be 87) and watching him struggle with her (lifting and trying to get her to understand he's changing her diaper, changing her clothes, etc.)...he shouldn't be doing this alone but from 8p.m to 10 a.m. he has her to himself and it's such a strain.
The family is giving Uncle Norman a birthday party for him and members of the family he hasn't seen in years will hopefully be there. Part of my contribution is composing a video of their relationship. Their song is "Always" sung by Frank Sinatra and I've chosen another song that shows his unyielding support for the love of his life. I'm incorporating photos from when they were teenagers, wedding, anniversaries, and throughout their lives and ending with videos I've taken of him helping her with the alzheimer's. My Aunt won't be able to understand it when it's shown (and she won't get to be at the party), but maybe...just maybe...she will remember only for a moment a photo that comes within view. That's my prayer anyway.
Anne...keep us posted on your Father's situation...sending you all hugs, love and prayers.