Multiple sclerosis (MS) is a neurological disease that causes symptoms like fatigue, impaired mobility, and speech issues. The most common types are RRMS or PPMS, each with different symptom timing and slightly different treatment approaches.

If you have MS, you probably already know your type. However, what you may not know are the differences between your type and the other types of MS.

Read on to learn about the two main types of MS.

Technically, there are four main types of MS:

CIS refers to a single episode of neurological symptoms that correspond with demyelination in the central nervous system. Demyelination means that the myelin sheath that insulates nerve cells in the brain, optic nerves, and spinal cord is damaged.

This episode’s symptoms usually last about 24 hours. As long as it remains just one incident, it isn’t considered MS, and it doesn’t mean you’ll go on to develop it.

SPMS, on the other hand, is when you’re no longer experiencing symptom remission. In addition, there are a few other less common types, such as extremely severe progression or, alternatively, markers of MS on imaging without any apparent symptoms.

RRMS is the most common form of MS. As many as 85% of people with MS receive an initial diagnosis of RRMS. RRMS is characterized by flare-ups or attacks of inflammation and demyelination in the central nervous system (CNS).

These flare-ups are followed by remission periods with improved or completely resolved symptoms. People living with RRMS sometimes gradually develop SPMS, usually after about 10 years.

RRMS symptoms come on suddenly and include episodes of:

PPMS is characterized by steadily worsening 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.

Ocrevus (ocrelizumab) is the only medication currently approved by the Food and Drug Administration (FDA) for treating PPMS.

New research and clinical trials are ongoing to find more treatments specifically for PPMS.

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

Relapsing-remitting MS (RRMS)Primary progressive MS (PPMS)
RRMS is diagnosed earlier. Most people receive a diagnosis of RRMS in their 20s and 30s.PPMS is diagnosed later. Most people receive a diagnosis of 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 females two to three times more often than males.PPMS affects males and females 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.

Generally, PPMS tends to affect the body’s ability to function more than RRMS.

For example, those with PPMS may find it more difficult to continue working because of their mobility issues and declining neurologic function.

There are several disease-modifying drugs to treat RRMS. Many of these can also be used to treat SPMS in people who experience relapses.

If you experience a relapse of RRMS, the usual treatment is a short course of IV steroids. The same treatment is usually needed for CIS.

But this isn’t the same for PPMS or SPMS because relapses are not usually part of the progression of these MS types.

RRMS, PPMS, and SPMS all require ongoing physical therapy. In cases of CIS or an exacerbation of RRMS, your doctor will make a new physical therapy assessment and plan.

What is the most severe form of multiple sclerosis?

Fulminate MS is a form of MS that progresses very fast and leads to severe symptoms within 5 years after diagnosis. It’s also called malignant MS or Marburg MS.

Can you still walk with PPMS?

People with PPMS usually experience more spinal cord damage than brain damage, resulting in walking problems. One of the early signs of this type is a slow decline in walking ability.

How often does RRMS turn into PPMS?

Research shows that about 10% to 15% of people with MS have PPMS, compared to 85% with RRMS.

RRMS and PPMS symptoms often differ from each other.

People with RRMS enter periods of flare-ups and remission. Those with PPMS are in a continual phase of deterioration.

Talk with your healthcare professional if you would like more information on the differences between RRMS and PPMS.