RRMS is characterized more by an inflammatory disease process while SPMS and other progressive forms are characterized more by nerve damage or loss.
- In RRMS, each relapse or attack of inflammation is followed by a period of remission — when the disease is relatively quiet and no apparent progression occurs. During a remission, symptoms may return to the level they were before the relapse, or the person may be left with some ongoing symptoms that don’t improve.
- In SPMS, the disease continues to progress and the symptoms continue to worsen whether or not the person is having a relapse. And over time, most people with SPMS experience fewer inflammatory relapses or none at all.
- For a visual illustration of how RRMS and SPMS differ, please explore our information about the four disease courses of MS.