Over time, relapsing remitting multiple sclerosis may get worse and transition to secondary progressive multiple sclerosis. With this type of MS, symptoms worsen slowly, whether there are relapses or not.
SPMS is characterised by times where:
- it’s active (with relapses or changes to brain activity)
- it’s non-active, and it may slowly get worse over time or stay the same.
While we know most people with RRMS will eventually experience SPMS, there’s currently no clinical test to show when RRMS changes to SPMS.
In the past, without treatment:
- the transition from RRMS to SPMS took about 10 years
- 90% of people with RRMS developed SPMS within 20 to 25 years after diagnosis.
Thanks to disease-modifying therapies, these figures are getting better and it’s becoming less likely that RRMS will lead to SPMS. And if it does, the transition takes longer.