The diagnosis, for me, 12 years ago was devastating. At the time, I basically pushed all those who wanted to help me away. I got over it, but it took me time and I had to come to the realization that life was going to go on and I had the choice of either dealing with it as best I could, or not. The first step for me was to find a neurologist who had a great attitude and was able to project a positive outlook and help to convince me that life wasn't over. I was shocked, terrified, and knew only of the stereotype that I was going to be wheelchair bound and inevitably on a slow and hopeless decline to a vegetative state. My second neurologist was instrumental in getting me to understand that that doesn't have to be the case.
Living in a state of despair and hopelessness will probably not do your brother any good physically. I am lucky; I respond well when I do the things that keep me healthy. I exercise, eat right, and above all, I take my medication as directed and when I'm supposed to. It is difficult to give you advice as to how you can help improve his life if he isn't willing to help himself improve it or allow there to be hope.