The changes are often not easy to recognize. But you may notice that your relapses may not seem to fully go away.
Most people with relapsing-remitting MS -- about 80% -- eventually get secondary progressive MS. The relapses and remissions that used to come and go change into symptoms that steadily get worse. The shift typically begins 15 to 20 years after you’re first diagnosed with MS.
Because multiple sclerosis is such a complex disease, it can be hard to spot the changes that signal SPMS, even for health professionals. Doctors often wait at least 6 months before they diagnose SPMS.
Symptoms of Secondary Progressive MS
Relapsing-remitting MS can be unpredictable, but there’s usually a pattern of clear attacks followed by times of recovery. With SPMS, relapses tend to be less distinct. They may happen less often or not at all. When you do have relapses, recovery is not as complete.
Along with these signs, there are other symptoms that might show you’re shifting to SPMS:
Your doctor can only diagnose SPMS by comparing your symptoms over time. So it's important that you tell her about any changes in your symptoms.
It’s not clear why people progress from relapse-remitting to secondary progressive MS.
Some scientists think it may be an aftereffect of nerve injury that happened early in the disease. But they need more research to understand what’s behind the shifts in the disease.
It’s often harder to treat secondary progressive MS than relapsing-remitting MS.
The main type of drugs for MS, called disease-modifying drugs (DMDs), make relapses happen less often and symptoms less severe. For people with SPMS who still have relapses, DMDs can still help. But for those whose symptoms just get gradually worse, the drugs don’t really work.