My first reaction on the MS story was “there’s no such thing as aggressive” but it appears that she has relapse remitting (RRMS) where the relapses are frequent and aggressive in nature.
Most people diagnosed with RRMS get it early, it’s generally younger women 18-30ish. Sweeping generalisations but largely that’s the case. It can affect limbs, cognitive ability, sight, tremors etc.
Once it gets to a point the relapses stop and it just gets worse. That’s Secondary Progressive (SPMS).
Then there’s Primary Progressive MS (PPMS) affecting about 10-15% of people. They’ve never had a relapse (generally) and it just gets worse. PPMS largely affects limbs, spine, spasticity (spasms in the limbs) , ability to walk fatigue, etc etc and rarely does it affect vision or cognitive ability in the same way as RRMS. Generally speaking this affects older males and likely to be diagnosed from late 30s onwards.
No two people are alike with MS, regardless of the type. Some People may get a light relapse every few years, some others may get relapses every few months or weeks. No two people have the same prognosis.
As I say I’ve been affected secondhand by this by someone I’m close to so we’ve had 15 years to research it and understand it. I’m not a medical professional, just speaking from life experience.
These are generalisations. There are always exceptions to the rule of course.