Sassy, you already know how I feel about Tysabri being right for ME.
I didn't have ANY previous problems before MS. If I had, I would have done everything I could to find out how Tysabri would affect whatever it was that I already had. If there wasn't enough information to satisfy me, I would have waited and looked at every other option.
I don't have anything else but hugs and support for you in whatever decision you make.