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. SPMS can be further characterized as either active
(with relapses and/or evidence of new MRI activity during a specified period of time) or not active
, as well as with progression
(evidence of disability accrual over time, with or without relapses or new MRI activity) or without progression
This graphic shows the kinds of disease activity that can occur in SPMS; however each person's experience with SPMS will be unique. Following a period of relapsing-remitting disease, disability gradually increases over time, with or without evidence of disease activity (relapses or changes on MRI). In SPMS, occasional relapses may occur, as well as periods of stability.
Why are modifiers used to characterize SPMS?
Disease activity and progression should be evaluated at least yearly by neurologic examination and MRI. Being able to characterize the course of your disease at different points in time helps you and your MS care provider discuss your treatment options and expected outcomes. For example:
- If you have SPMS that is active, you and your MS care provider will want to talk about treatment with a disease-modifying therapy to reduce the risk of a relapse.
- If you have SPMS that is active and progressing despite the medication you are taking, the conversation with your MS care provider might be about the potential benefits and risks associated with switching to a more aggressive treatment strategy.
- If your SPMS is not active but there is evidence of progression and accumulation of disability, you and your MS care provider will want to focus on rehabilitation strategies to help improve your function and mobility, and promote safety and independence.
- If your SPMS is stable without activity or progression, the conversation with your MS care provider could focus on rehabilitation and other symptom management strategies to help you maintain function.
How does SPMS differ from the other disease courses?
SPMS occurs in people who initially had a relapsing-remitting disease course. In other words, SPMS occurs as a second phase of the disease for many individuals.
In SPMS, people may or may not continue to experience relapses caused by inflammation; the disease gradually changes from the inflammatory process seen in RRMS to a more steadily progressive phase characterized by nerve damage or loss.
Read more about strategies to help you lead a full life with secondary progressive MS.
When does the transition occur?
Prior to the availability of the approved disease-modifying therapies, studies indicated that 50 percent of those diagnosed with relapsing-remitting MS (RRMS) would transition to secondary-progressive MS (SPMS) within 10 years, and 90 percent would transition within 25 years.
While MS experts agree that the medications have an impact on disease progression, it is too soon to tell the extent to which the disease-modifying treatments alter or delay the transition to SPMS.
The National MS Society is pursuing all promising research paths and collaborating worldwide to drive progress in research in progressive MS, for which few therapies exist. Learn more about progressive MS research