If you have multiple sclerosis (MS) you probably already know your type. But what you may not know are the differences between your type and the other types of MS. Each type is unique and has different symptoms and treatment methods.

There are four different types of MS:

  • clinically isolated syndrome (CIS)
  • relapsing-remitting MS (RRMS)
  • primary-progressive MS (PPMS)
  • secondary-progressive MS (SPMS)

Out of these four types, research has shown that RRMS and PPMS are more similar than their symptoms reveal. Keep reading to learn about these two types of MS and what research has to say about their similarities.

Relapsing-remitting MS (RRMS)

RRMS is the most common form of MS. It affects as many as 85 percent at initial diagnosis. RRMS is characterized by flare-ups or attacks of inflammation in the central nervous system. These flare-ups are followed by remission periods with improved or completely resolved symptoms. People who’ve been living with RRMS for 10 years gradually develop SPMS.

RRMS symptoms come on suddenly and include episodes of:

  • fatigue
  • numbness and tingling
  • spasticity or stiffness
  • disturbed vision
  • bladder and bowel problems
  • cognitive issues

There are several disease-modifying therapies available to treat RRMS. Many of these can also be used to treat progressive forms of MS in those that experience relapses.

Primary-progressive MS (PPMS)

PPMS is characterized by a steady worsening of neurologic function without distinct attacks or remission periods. This type of MS involves considerably less of the type of inflammation seen in RRMS, resulting in fewer brain lesions and more spinal cord lesions.

There are currently no medications approved by the FDA for treating PPMS. However, disease-modifying medications used to treat other forms of MS may help reduce inflammation in the central nervous system. This is where nerve degeneration occurs for those with PPMS.

New research and clinical trials are ongoing to find a medication specifically for PPMS.

RRMS vs. PPMS

The following are some of the key differences between RRMS and PPMS:

RRMSPPMS
RRMS is diagnosed earlier. Most people are diagnosed with RRMS in their 20s and 30s.PPMS is diagnosed later. Most people are diagnosed with PPMS in their 40s and 50s.
People with RRMS tend to have more brain lesions with more inflammatory cells.Those with PPMS tend to have more spinal cord lesions and fewer inflammatory cells.
RRMS affects women two to three times more often than men.PPMS affects men and women equally.
People with RRMS will likely have mobility issues, but these issues are more gradual. People with PPMS often experience more mobility issues and have more trouble walking.

In general, PPMS tends to be more debilitating than RRMS. Those with PPMS may therefore also find it more difficult to continue working because of their impaired mobility and declining neurologic function.

Overview

As far as symptoms, RRMS and PPMS are oftentimes very different from each other. People with RRMS enter periods of flare-ups and remission, while those with PPMS are in a continual phase of deterioration.

However, recent research has shown through MRI scans that certain characteristics, such as the amount of demyelination, overlap. More research is still needed to see if there are other links between RRMS and PPMS.

Want to learn more about the different types of MS? Check out Healthline’s Multiple Sclerosis Topic Center.