If your family is worth having at all, they are worth being honest with. It is the only way to allow them to walk this path with you. Some of them might turn out to be total flakes in the face of neurological illness, but that's not necessarily a bad thing to know now rather than later.
Serious stuff out of the way, I offer you this bit of humor:
I was already a wheelchair user when I began attending my church. I had come from a non-liturgical tradition, and so all of the physical ritual of orthodoxy was strange to me. I adapted it as best I could to my physical ability of the time, but I always longed to participate more fully. I figured out how to get out of my wheelchair, do a prostration, and get back in, but it took ages. After a while, I realized that wasn't necessarily a deal killer in this christian tradition, that it was ok if things took as long as they took. So on a previous year's Holy Friday I got on the end of line to venerate the winding sheet and receive a blessing from the priest. My transfer to the ground was flawless, but so surprised my fellow congregants that half of them tried to "save me from falling". We don't have a traditional choir, and all of our music is acapella, so the sound (or sudden lack of it) this produced was stark. I couldn't have stuck out more if I had attached bright neon lights to my powerchair!
It gets, better, though. Once your local parish is educated on you and you make it through those experiences, your needs and ways of doing things will just become part of parish life. The more you let them, just like your family in a way, in on what you need and how you need to do things, the more they can do their part in making that happen.
