Yes, you read it right; there are four different types of Multiple Sclerosis (MS). Each type simply reflects the characteristics of the disease’s progression; all forms of MS are still chronic.
The four types of Multiple Sclerosis include;
Relapsing-Remitting Multiple Sclerosis (RRMS)
This is the most common form of MS. About 85% of people with MS are initially diagnosed with RRMS. People with RRMS have temporary periods of recognizable disease progression called “relapses”, “flare-ups”, or “exacerbations” where new or old symptoms appear.
Secondary-Progressive Multiple Sclerosis (SPMS)
In SPMS, symptoms worsen more steadily over time with or without the occurrence of relapses and remissions. Most people who are diagnosed with RRMS will transition to SPMS at some point.
Primary-Progressive MS (PPMS)
This type of MS is not very common, occurring only in about 10% of people with MS. PPMS is characterized by slowly worsening symptoms with no relapses or remissions.
Progressive-Relapsing MS (PRMS)
A rare form of MS (About 5% of MS patients have PRMS) characterized by a steadily worsening disease state from the very beginning with acute relapses but no remissions with or without recovery.
Course of the Disease
In the above image, the line starts on the left of the chart at “baseline”, that is, where one’s health was before Multiple Sclerosis had taken effect. In relapsing-remitting MS (for example) you can see you’re likely to return close to your baseline after a relapse. In all forms of MS your long term disability (where your baseline is) becomes more severe at different rates which can be seen by the baseline getting higher and higher on the chart over time after each relapse. The goal of MS treatments is to slow down the disease progression and lessen the long-term disability effects of MS. So an MS treatment, or DMT (Disease Modifying Treatment), aims to keep your baseline at the end of a relapse as close to your original baseline as possible.
Without the proper treatment, you may suffer more relapses over a given period of time and you’re likely to experience much more rapid disease progression resulting in a much greater worsening of long-term disability. As of now, treatments have only been FDA approved for use in relapsing-remitting Multiple Sclerosis (RRMS). Though your health insurance may not cover it, there are signs that certain DMTs can help slow the progression of the disease in secondary progressive Multiple Sclerosis (SPMS). Chemotherapy drugs have also shown to slow the progression of MS and some say that treatments like plasmapheresis (the removal and replacement of the plasma in the blood with artificial plasma) may also help in progressive forms of MS. Although they may reduce the rate of relapses, it is not certain if any of these drugs actually reduce the long-term disability in SPMS patients.