Secondary Progressive MS
Secondary progressive MS (SPMS) is one of several types of MS. SPMS develops after a person has had relapsing remitting MS (RRMS). After a period of time with relapses and remissions, symptoms begin to slowly get worse.1,2
In order to be diagnosed with SPMS, you need a history of RRMS. However, the transition between RRMS and SPMS is not always clear. You can go from RRMS to SPMS slowly over several years.
Typically in RRMS, attacks of symptoms will improve partially or completely. But when a person has SPMS, symptoms do not resolve as much. If symptoms continue to get worse after an attack, a person may have crossed into SPMS. In order to determine whether the transition has occurred, your doctor will take a careful medical history. They will also perform regular neurologic exams.1,2
Types of SPMS
SPMS can be divided into different categories. It can be classified as active or not active. People with active SPMS may still have relapses (sudden increases in the severity of symptoms). In addition, a person with active SPMS develops new MS lesions on brain imaging over a period of time. SPMS can also be classified as being with or without progression. When a person is progressing, their symptoms are getting worse. When a person does not have progression, they have few or no new symptoms. This is also called having stable SPMS.
All types of SPMS can happen in the same person. They can also change over time. For example, once a person is diagnosed with SPMS, they may have new brain lesions that develop. During this same period, their symptoms may be getting worse. This would be active SPMS with progression. If over the next few years symptoms do not get worse and brain images remain the same, SPMS would be not active and without progression. Several years later, the same person could have worsening symptoms but no new MRI findings. At this point, SPMS would be not active but with progression.1
Why do types of SPMS matter?
Each person will have a different experience with SPMS. There is no 1 pathway of SPMS for everyone. It is possible for someone to have several types of SPMS while someone else has the same type for a long time.
Even though each person is unique, there are benefits to monitoring SPMS. People with active SPMS or SPMS that is progressing may benefit from changing treatment options. As symptoms continue to progress, physical therapy or other symptom management may become more important. Someone who is not progressing and has SPMS that is inactive may be doing well on their current treatment and not need adjustments.1
SPMS versus other forms of MS
SPMS is different from both RRMS and primary progressive MS (PPMS). PPMS does not start with an initial relapsing remitting course like SPMS. It is a gradual worsening of symptoms from the beginning. It is less common to have definite relapses with PPMS. On the other hand, people with SPMS start with relapses (RRMS) and may still experience them.
PPMS only affects about 10 percent of people with MS. About 80 to 90 percent begin with RRMS. Before disease-modifying drugs were available for those with RRMS, nearly everyone would progress to SPMS within 25 years.
Now, everyone with SPMS still starts with RRMS. However, treatment can delay the time to progression or keep progression from happening. Research is ongoing to figure out how much of an impact disease-modifying drugs have on the progression to SPMS. Regardless, it is much more common for a person to develop RRMS that progresses to SPMS rather than PPMS only.
Although figuring out when the transition from RRMS to SPMS occurs can be hard, there are some differences. In RRMS, the symptoms that arise during an attack often completely or partially resolve afterward. In SPMS, symptoms never resolve and continue to worsen. Also, attacks in RRMS are mainly due to increased inflammation. In SPMS there is less inflammation. Some attacks can still be caused by active inflammation, but most symptoms are due to permanent damage caused by past inflammation.1,2
Not all MS drugs are effective for treating SPMS. Research is underway to find more treatments for SPMS. Examples of drugs that are approved for active SPMS are siponimod and cladribine. If you have SPMS, talk with your doctor about the treatment options available to you.1-3