Forms of multiple sclerosis: What are the similarities and differences?

Multiple sclerosis (MS) is a disease of the central nervous system (CNS), which includes the brain, spinal cord and optic nerves. The underlying biology is similar for everyone, but its course and symptoms vary from person to person. The majority of people with MS initially have a relapsing-remitting or primary progressive form of MS identified at diagnosis. Explore the similarities and differences between these two forms of MS.

How are the forms of MS similar?

Underlying biology

In every form of MS, the immune system attacks nerve cells in the CNS, which can cause symptoms and disability.

Disease course

Both RRMS and PPMS are marked by worsening signs or symptoms at some point during the course of the disease.


Symptoms are similar across all forms of MS, but differ for each person, no matter which form.

Most people with RRMS and PPMS experience an increase in physical disability at some point in time.


Both man and woman can be diagnosed with RRMS and PPMS.

Disease activity

Disease activity may be outwardly apparent with new or worsening signs or symptoms, or underlying, such as lesions (inflamed or damaged areas of the central nervous system) that are detected with special equipment like magnetic resonance imaging (MRI).10

Treatment goal

An important goal of treating RRMS and PPMS is to slow the progression of disability as early as possible.

Forms of MS at diagnosis

Relapsing-remitting MS (RRMS)
RRMS is the most common form of the disease. Approximately 85% of people with MS are initially diagnosed with RRMS.¹
Primary progressive MS (PPMS)
PPMS is a highly disabling form of the disease. Approximately 15% of people with MS are diagnosed with PPMS.¹

Course of the disease

Relapsing-remitting MS (RRMS)
RRMS is characterised by episodes of new or worsening signs or symptoms (relapses) followed by periods of recovery (remission).²,³ The recovery between relapses may be complete or may leave lingering problems.
Primary progressive MS (PPMS)
PPMS is a debilitating form of the disease marked by steadily worsening symptoms, typically without distinct relapses or periods of remission.⁴ However, some people with PPMS do experience relapses. PPMS tends to be more disabiling than RRMS. The accumulation of irreversible disability is twice as high in PPMS than in RRMS, which can mean people with PPMS rely more on mobility aids or wheelchairs.


Relapsing-remitting MS (RRMS)
The most common symptoms in RRMS include episodic bouts of fatigue, numbness, vision problems, spasticity or stiffness, and bowel and bladder problems.
Primary progressive MS (PPMS)
The most common symptoms in PPMS include progressive weakness, mobility issues and spasticity. These symptoms are not unique to PPMS but tend to be more persistent and difficult to manage.⁵ People may also have more problems thinking and speaking compared to people with RRMS.⁶ There is a sharp decrease in quality of life following arm function loss, which may happen earlier in people with PPMS.⁷

Age at diagnosis

Relapsing-remitting MS (RRMS)
RRMS is usually diagnosed when people are in their 20s and 30s.
Primary progressive MS (PPMS)
PPMS is usually diagnosed 10 years later than RRMS⁵, after a steady decline in physical abilities can be identified and other diseases can be ruled out. This means diagnosis most often occurs in people in their 40s and 50s.

Ratio of men and women diagnosed

Relapsing-remitting MS (RRMS)
RRMS affects women two to three times more often than men.⁹
Primary progressive MS (PPMS)
PPMS affects men and women equally.⁵

Disease activity

Relapsing-remitting MS (RRMS)
People with RRMS often have more active lesions than people with PPMS
Primary progressive MS (PPMS)
People with PPMS usually have a lower number of active lesions compared to people with RRMS and more spinal cord lesions that may lead to walking problems.⁵

Unment clinical need

Relapsing-remitting MS (RRMS)
Despite available treatments, some people with RRMS continue to experience disease activity and worsening disability. Recent advances in the scientific understanding of MS have resulted in the development of treatments that may effectively slow disease progression in RRMS.
Primary progressive MS (PPMS)
PPMS is a highly disabling disease, therefore treatment should be based on clinical need and initiated as early as possible. Recent advances in the scientific understanding of MS have resulted in the development of new treatments that may slow disease progression in PPMS. There are no approved disease-modifying treatments for people with PPMS in many countries around the world, including Europe.
Trouble with the Social Network

How are the forms of MS different?


  1. National Multiple Sclerosis Society. Types of MS. Available at Accessed June 2017.

  2. Lublin F.D., Reingold S.C. (1996) Defining the clinical course of multiple sclerosis: results of an international survey. National Multiple Sclerosis Society (USA) Advisory Committee on Clinical Trials of New Agents in Multiple Sclerosis. Neurology, 46(4):907–11.

  3. Lublin F.D. et al. (2014). Defining the clinical course of multiple sclerosis. Neurology, 83(3):278-86.

  4. MS Society. Primary Progressive (PPMS). Available at Accessed June 2017.

  5. Holland NJ, Schneider DM, Rapp R, Kalb RC. Meeting the Needs of People with Primary Progressive Multiple Sclerosis, Their Families, and the Health-Care Community. International Journal of MS Care. 2011;13(2):65-74.

  6. Planche V., Gibelin M., Cregut D., Pereira B., Clavelou P. Cognitive impairment in a population-based study of patients with multiple sclerosis: differences between late relapsing-remitting, secondary progressive and primary progressive multiple sclerosis. Eur J Neurol. 2016;23(2):282-289.

  7. Kobelt, Gisela, et al. (2017). New insights into the burden and costs of multiple sclerosis in Europe. Multiple Sclerosis Journal, 23(8):1123–1136. Available at:

  8. Multiple Sclerosis International Federation. What is MS? Available at . Accessed June 2017.

  9. Multiple Sclerosis International Federation. (2013). Atlas of MS 2013. Available at: . Accessed June 2017.

  10. Erbayat A, et al. (2013). Reliability of classifying multiple sclerosis disease activity using magnetic resonance imaging in a multiple sclerosis clinic. JAMA Neurol, 70(3):338-44.


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