Types of MS

MS is a continuous disease process because it progresses through different stages over time. Everyone with MS has a unique disease course that can vary widely in severity, symptoms, progression rate, and response to treatment. Based on their medical history and an exam by a neurologist, people may be initially diagnosed with one of the following:

Radiologically isolated syndrome (RIS) refers to demyelination seen on MRI which is suggestive of MS, but without any physical symptoms or signs of the disease. Nearly half of all people with RIS will be diagnosed with MS within ten years.

Clinically isolated syndrome (CIS) refers to a single episode of neurological symptoms suggestive of MS. Not everyone with CIS will be diagnosed with MS, however over the longer term, about 80% of people develop more MS disease activity that leads to a diagnosis of MS. Regular follow-up with a neurologist and brain imaging may be recommended to ensure appropriate treatments and supports are ready at the right time.

Relapsing-Remitting MS

Between 85-90% of people living with MS are initially diagnosed with relapsing-remitting MS (RRMS), characterized by neurological symptoms called relapses (also called attacks, exacerbations, and flare-ups), followed by complete or partial recovery (remission).

Progressive MS

Some people with RRMS will transition to a phase of the disease called secondary progressive MS (SPMS). This phase of the disease has fewer relapses with increasing disability progression. The rate of worsening is different for everyone and typically is more gradual than the worsening experienced with an MS relapse.

About 10% of people will be diagnosed with primary progressive MS (PPMS). PPMS is characterized by a slow accumulation of disability, which usually doesn’t include relapses. Overall, there are no periods of significant improvement or return of function over time. PPMS is usually diagnosed later than other forms of MS and affects men and women equally. See Progressive MS.