Any confusion dementia success stories of the elderly?

Please tell me there's hope. Are there any success stories of a loved parent etc. that all seemed to given up on but had a turnaround. What helped. . .please let me know. I will never give up on my dad. Any success stories of someone who was not expected to rehabilitate and was elderly. Any advice. .. please. P.S. Please say a prayer for my dad and our family. I will always have Faith :-)