from the perspective of someone who has also been diagnozed with MCI, I will say this about your husband's future: don't give up hope. The doctor who diagnozed me was adamant that I needed to go on the dementia drugs, but I was able to bring up my MoCA test to the point where I am no longer officially considered to have MCI. I'm not saying life is easy (I am still a work-in-progress), but now I have great hope that I will not be going down the same path as my grandmother, father, and brother. Do your research. Learn everything you can about the multiple ways to help a vunerable brain. One of my favourite strategies is to play brain games, because I find it so gratifying to see my games scores gradually improving. The brain game company whose results are the most scientifically validated seems to be Brain HQ. Good luck, and know that I am rooting for you and your husband!