Iris
I think a better treatment of the subject of Altzheimers is the 2001 British film "Iris" starring Judy Dench as the famous author Iris Murdoch. "Iris" was much grittier and more realistic. It also showed more of the latter stages, and it had a fuller representation of the problems of being a loving husband in this situation. It wasn't nearly as attractive in a Hollywood-ish way, of course. J.M. does a great job but she doesn't hold a candle to the depth that Judy Dench managed to portray, in my opinion. There are so many scenes in "Iris" that have remained seared in my memory 15 years later, and I don't expect the same effect will result from "Still Alice."
Unfortunately "Iris" is not a film that would appeal to a mass U.S. audience, because it IS so gritty and realistic, and doesn't have any Hollywood polish.