Types of MS
Four disease courses have been identified in multiple sclerosis: clinically isolated syndrome (CIS), relapsing-remitting MS (RRMS), primary progressive MS (PPMS), and secondary progressive MS (SPMS). Some of them can also be categorised as active / not active and progressive / not progressive.
Clinically Isolated Syndrome (CIS)
CIS is a first episode of neurologic symptoms caused by inflammation and demyelination in the central nervous system. This type of episode is characteristic of multiple sclerosis but does not yet meet the criteria for a diagnosis of MS as it has only happened once.
Relapsing Remitting MS (RRMS)
RRMS is characterised by clearly defined attacks of new or increasing neurologic symptoms. These attacks – also called relapses or flare ups (see more info below) – are followed by periods of partial or complete recovery and remissions.
Primary Progressive MS (PPMS)
PPMS is characterized by worsening neurologic function (accumulation of disability) from the onset of symptoms, without early relapses or remissions.
Secondary Progressive MS (SPMS)
SPMS follows an initial relapsing-remitting course. Some people who are diagnosed with RRMS will eventually transition to a secondary progressive course in which there is a progressive worsening of neurologic function (accumulation of disability) over time.
Active / Not Active
Progressive / Not Progressive
Both PPMS and SPMS can be further characterised as either active (with relapses and/or evidence of new MRI activity over a specified period of time) or not active, as well as with progression (evidence of disability accumulation over time, with or without relapse or new MRI activity) or without progression.
Relapses / Flare-ups
A relapse or flare up is the occurence of new symptoms or the worsening of old symptoms. It can be very mild, or severe enough to interfere with a person’s ability to function.