A Song for Martin

From Netflix: Barbara (Viveka Seldahl) is a violinist who's attracted to Martin (Sven Wollter), a famous composer. Despite being married to other people at the time, the two fall in love and get married, sure that they'll enjoy a blissful life together. But when Martin is diagnosed with Alzheimer's disease, his mind and their relationship begin to deteriorate, as Barbara tries to hold on to the man who was once so vibrant and gifted. 2001 113 minutes

In my opinion, this is a better film than "Away from Her" and it deals with essentially the same subject.

Availability:
Netflix