Multiple Sclerosis is a condition that varies from very severe to very mild. MS is divided into four types.
Relapsing Remitting MS
This is the most common kind of MS. RRMS has a course of discrete attacks, usually lasting longer than 24 hours, followed by recovery. There may be changes in the brain that represent attacks of symptoms over many months or years. Almost all of the MS treatments are designed for this type.
Secondary Progressive MS
This is a type of MS in which there is a steady, slow decline in function, without individual attacks. It tends to occur many years after a course of Relapsing Remitting MS. For some reason, not everyone with Relapsing Remitting MS develops this subtype. There are a few treatments that are helpful for this type of MS.
Primary Progressive MS
This is a very rare type of MS that never has attacks. Often, there are no lesions in the brain in this type of MS. For that reason, it is difficult to diagnose. There are no treatments that are considered very helpful for this type of MS
Progressive Relapsing MS
This is also a rare type of MS. In this case, there are attacks of symptoms, without recovery. Changes in the brain may be found on MRI. This type of MS may respond to treatment, but MS treatments are not designed specifically for this type.