SPMS follows an initial relapsing-remitting course. Most 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 at different points in time as either active
(with relapses and/or evidence of new MRI activity) or not active
, as well as with progression
(evidence of disease worsening on an objective measure of change over time, with or without relapses) 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 in spite of 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 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. Primary progressive MS (PPMS) is the first — and only — phase of the illness for approximately 15 percent of people with MS.
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.
The disease-modifying therapies may be effective for people with SPMS who experience relapses.