Legal aspects are one side of the coin, but the more important is your responsibility and feel upon the possible risk. MS is a multi-headed hydra and almost impossible to fetch by general statements. It is a disease that affects the central nervous system and the progress is very hard to predict, in speed and severity - my mom was under treatment for over 30 years, so I have some insight to possible sneaking in things. I heard rumors of pilots flying with MS under very close supervision. Is your neurologist familiar with the world of flying, is able to be an adequate discussion partner for the CAA and also open for a continuous supervision to satisfy requirements set by the special job environment? I would ask myself exactly one question: could I stand the shoulding myself to death if I hurt somebody by not quitting early enough?