Empowering people affected by MS to live their best lives

Multiple sclerosis is a chronic, unpredictable disease of the central nervous system. The brain, spinal cord and optic nerves make up the central nervous system.Scientists think MS is an immune-mediated disorder. This means that the immune system attacks your own healthy tissue in the central nervous system. The immune system is the body’s natural defense against illness. This causes inflammation and damage to the central nervous system. This disrupts the signals to and from the brain and spinal cord and other parts of the body, causing the symptoms of MS.MS is currently divided into 4 different types, or disease courses, as defined by the International Advisory Committee on Clinical Trials of MS in 1996. They are:

Clinically isolated syndrome (CIS)
Relapsing-remitting MS (RRMS)
Secondary progressive MS (SPMS)
Primary progressive MS (PPMS)

Knowing the type of MS you have may help you know what to expect over the long term. It can also help you and your healthcare provider decide what type of disease-modifying therapy (DMT) might be best for you. Learn more about each disease course below.

Clinically isolated syndrome (CIS)
Relapsing-remitting MS (RRMS)
Secondary progressive MS (SPMS)
Primary progressive MS (PPMS)

Clinically isolated syndrome (CIS) refers to a first episode of neurologic symptoms. If you experience CIS, you may or may not go on to develop MS. Symptoms of CIS vary from person to person but commonly include bladder dysfunction, vision problems, and difficulty with coordination, balance, walking, speaking and swallowing (ataxia).Studies show that early treatment of CIS delays the onset of MS.Read More About CIS
Relapsing-remitting MS (RRMS) is the most common MS disease course. RRMS shows clearly defined attacks of new or increasing neurologic symptoms. These attacks are also called relapses or exacerbations. They are followed by periods of partial or complete recovery, or remission.Approximately 85% of people with MS are initially diagnosed with RRMS. When the disease course progresses, it is considered to be secondary progressive MS.Learn More About RRMS
Some people diagnosed with RRMS eventually go on to have a secondary progressive MS (SPMS) course. In this course, neurologic function declines progressively and disability increases over time.Each person’s experience with SPMS is unique. In SPMS, you may have occasional relapses, as well as periods of stability.Learn More About SPMS
With PPMS, neurologic function worsens or disability accumulates as soon as symptoms appear. There are no early relapses or remissions. Approximately 15% of people with MS are diagnosed with PPMS.Each person’s experience with PPMS is unique. PPMS can have brief periods of stability, with or without a relapse or new MRI activity. It can also have periods of increasing disability, with or without new relapses or lesions on an MRI.Learn More About PPMS

Radiologically Isolated Syndrome (RIS)

Radiologically isolated syndrome (RIS) is not considered a course of MS. But it has been used to classify those with:

Lesions on the brain or spinal cord — not explained by another diagnosis — consistent with lesions of MS AND
No past or current neurological symptoms or abnormalities found on a neurological exam

Often these individuals had an MRI because of other symptoms, such as headache. The results showed lesions similar to those seen in MS.A 2020 study found that more than half of those with RIS go on to develop MS within 10 years. There are no specific treatment guidelines for RIS. Doctors need more research results to better understand what factors increase the likelihood that someone with RIS will develop MS. If you have RIS, experts recommend that you monitor your MRIs and neurological symptoms and have regular neurological exams. This way, you can quickly identify changes in the disease course.Several studies are ongoing that could provide more guidance for monitoring and treatment. A 2022 study, for instance, supports the idea that early treatment is protective and that MS can begin well before symptoms emerge.

Treatments for MS

More than 20 disease-modifying therapies have been approved by the U.S. Food and Drug Administration (FDA) to treat the different types of MS. The FDA indicates which type of MS each drug can treat. More treatments are available for relapsing forms of MS than for primary progressive MS. Addressing the challenges of progressive MS is a primary target of the Society’s research strategy.

Radiologically isolated syndrome (RIS) is not considered a course of MS. But it has been used to classify those with:

Lesions on the brain or spinal cord — not explained by another diagnosis — consistent with lesions of MS AND
No past or current neurological symptoms or abnormalities found on a neurological exam

Types of MS

Clinically Isolated Syndrome (CIS)

Relapsing-Remitting MS (RRMS)

Secondary Progressive MS (SPMS)

Primary Progressive MS (PPMS)

Radiologically Isolated Syndrome (RIS)