The doc may be referring to the fact a lot of people do plateau eventually and at that stage may see no further progression. Sure, this could be interpreted as MS having run it course, however, in many cases this means they will have reached an EDSS of 7.5, 8 or 9 or at the least have quite a lot of none- reversible disability.
That's interesting. I've seen evidence for and have wondered the same thing. At one point it even seemed to me that if researchers could figure out what was causing MS to slow down at that point, maybe they could invoke the same event, only much earlier and lower disability level.
After more thought it seemed to me that every imaginable scenario required the brain to have been previously ravaged. A seemingly unlikely prospect to eke any benefit from.
That is a really interesting subject though. Too bad it's so hard to find specific information in that regard.