Secondary Progressive Multiple Sclerosis (SPMS)

Secondary progressive multiple sclerosis (SPMS) is a stage of multiple sclerosis (MS) that follows the initial relapsing-remitting form (RRMS) in most patients.

Whereas RRMS is marked by periods of remission — times when disease symptoms become less severe — in SPMS, a person’s symptoms steadily worsen over time. There still may be symptom relapses, but changes in symptom severity are generally less drastic than in the RRMS stage and symptoms do not disappear even in the remission phases.

SPMS can be classified as active or not active, based on whether the individual experiences disease relapses or has evidence of new brain lesions. It also can be classified as with or without progression, based on patterns of disability accumulation over time.

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SPMS therapies

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Transitioning from RRMS to SPMS

Nearly all people with RRMS eventually will develop SPMS. However, because of advancements in disease-modifying treatments, fewer people today develop SPMS than before, and the transition to SPMS occurs later. The median time to progression to SPMS from RRMS is about 20 years. 

Exactly what causes the progression from RRMS to SPMS isn’t completely understood, and there is no single test that defines when MS changes from RRMS to SPMS. A diagnosis of SPMS typically is made after carefully reviewing the progression of the disease in the preceding months and years. Often, six to 12 months of progression must be noted before a person is considered to have progressed to SPMS.

Whereas RRMS symptoms are thought to be driven by active inflammation, SPMS is driven by neurodegeneration, meaning nerve damage that worsens over time. Imaging of the brain generally reveals more new and/or inflammatory lesions in the brains of people with RRMS, relative to those with SPMS.


Last updated: July 8, 2021


Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.

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