I've read info that states that the older you are, the MILDER your MS will be. But my neuro has stated in many lectures that it's the length of time that will determine disability. He feels, after years of treating MS patients, that after 10 years many MS patients will go from RRMS to SPMS, with disability in some form or another presenting.
I was dxd when I was 53, but had sxs for years before, mostly blamed by various neuros on migraines (never had them) or my fibro, which has many of the same sxs as MS.
It worries me that my neuro has told me that my MS has "changed." won't put letters to it, but we both know that I'm not doing very well.
I just feel so bad for the MSers who get it so young. They are looking at a very long, hard road ahead.