When experts think about how a disease such as MS affects people in different ways, they try to identify typical patterns or characteristics that describe different forms or courses of the disease. When we use the term disease course, we are talking about typical patterns a disease may take.
Four different types of MS recognized
Previously, experts in MS recognized four different courses or types of MS. These include:
- Progressive-relapsing MS, or PRMS
- Secondary-progressive MS, or SPMS
- Primary-progressive MS, or PPMS
- Relapsing-remitting MS, or RRMS
Revised guidelines to better define MS types
However, in 2014, revised guidelines were published to better define MS types, including modifiers within those types. These include:
- Clinically isolate syndrome (CIS) - Active or not active
- Relapsing-remitting MS (RRMS) - Active or not active
- Primary-progressive MS (PPMS) - Active and with progression, Active but without progression, Not active but with progression, Not active and without progression (stable disease)
- Secondary-progressive MS (RRMS) - Active and with progression, Active but without progression, Not active but with progression, Not active and without progression (stable disease)
Four Courses of Multiple Sclerosis
MS Course
Description
Percentage of MS patients affected
Clinically Isolated Syndrome
- Recognized as the first clinical presentation of a disease that shows characteristics of inflammatory demyelination that could be MS
- Does not yet fullfill criteria for dissemination in time
- Begins as RRMS, with patient later developing a worsening of disease
- May or may not involve occasional attacks with minor periods of remission
- It is difficult to predict which patient with RRMS will develop SPMS
About 50% of people with RRMS develop SPMS within 10 years of diagnosis
- Patient has slowly worsening disability from the beginning, without attacks or remissions
- The rate of worsening may vary over time: patient may experience periods of stability, with temporary minor improvements
- Data suggest that PPMS is a part of the spectrum of progressive MS phenotypes and that any differences are relative rather than absolute
About 10% of people with MS are diagnosed with PPMS initially
- Patient has clearly defined relapses (also called flare-ups, exacerbations, attacks) in which neurologic function gets worse
- Attacks are followed by periods of partial or complete recovery (also called remissions) when patient is stable (no progression of disease)
About 85% of people with MS are diagnosed with RRMS initially
