There are 4 MS disease courses or types — the most common of which is relapsing-remitting multiple sclerosis.
These four courses of the disease were developed to both highlight differences in the progression of MS and identify the diagnostic criteria for the disease. There are two core elements to these different types: 1) the disease activity; and 2) the disease progression.
At any given moment in time, MS can be active or not active. It can also be stable or getting progressively worse. Depending on the status of the disease, MS can be defined using the four classifications developed by the International Advisory Committee on Clinical Trials of MS:
- Clinically Isolated Syndrome (CIS)
- Relapsing-Remitting MS (RRMS)
- Primary Progressive MS (PPMS)
- Secondary Progressive MS (SPMS)
Note: Progressive Relapsing MS (PRMS) was removed as a course when these classifications were redefined in 2013. PRMS would now be considered primary progressive MS.