Like Sleeper, I'm Primary Progressive. I've never had annual MRI's. I had one two years ago and there were literally no real changes from the one done many years earlier.

I have progressed measurably and consistently every year for 20 years to where I cannot do much of anything for myself.

So I'd guess with PP maybe the changes aren't reflected by MRI

I'm a Quad. I'm in a Care Home. (aka Nursing Home) I see my husband about once a week.

MS takes away so much more than one's abilities. It steals one's life.