I get to visit people in nursing homes regularly. It is part of the work I do. Recently, the two of us dropped off a live Easter lily featuring multiple blooms to a lovely lady suffering from slowly advancing dementia. She was uncertain about some things, but the beauty of the flowers drew her out. Also, she knew just what to do with them, asking if they'd need anything more than simple watering from time to time.
Flowers have a magic about them. Just as the music of childhood and early adulthood does for someone suffering from cognitive issues. If you are caring for a loved one who is slowly slipping away as their minds drift with advancing years, head over to the florist or the grocer. Scoop up some flowers, fresh cut or in a pot, and take them along. The person you are delivering them to will not be the only person to have their day brightened by the bouquet.
Disclaimer: I have no medical advice to give, just this simple observation. I also offer my support as you go through this difficult time with a loved one. Make sure to take good care of yourself as this situation is very taxing on a caregiver, especially when problems faced cannot be solved.