Relapsing-remitting multiple sclerosis (RRMS)

Last updated Sept. 7, 2022, by Marisa Wexler, MS
Fact-checked by Ines Martins, PhD

Multiple sclerosis (MS) is a neurological disorder in which excessive inflammation in the central nervous system causes damage to nerve cells. Based on how MS symptoms develop and progress, the condition is classified into several types.

About 85% of people with MS are diagnosed first with the relapsing-remitting form of the disease, in which relapses are interspersed with periods of remission.

What is relapsing-remitting MS?

Relapsing-remitting MS, commonly abbreviated as RRMS, is defined by periods of new or worsening symptoms — called relapses, exacerbations, attacks, or flare-ups — followed by periods of remission where symptoms ease.

A relapse is defined by the appearance of new symptoms or the return of past symptoms for 24 hours or more without a change in body temperature or infection. It also must occur at least 30 days after the start of a previous relapse.

These periods of new symptoms are caused by the immune system launching an inflammatory attack that damages nerve cells. They can last anywhere from a few days to a few months, but usually patients experience them for about four to six weeks.

Relapses are followed by periods of partial or complete recovery from symptoms called remissions. During remissions, all of the symptoms may disappear or some may continue and become permanent. However, there is no apparent disease progression (symptoms do not continually worsen) during this time. This sets RRMS apart from progressive forms of MS, where symptoms continually worsen over time even in the absence of relapses.

Relapsing-remitting MS can be characterized as active — if patients experience relapses and/or have evidence of new disease activity on MRI scans — or nonactive. It also can be described as worsening or not worsening, depending on whether or not there is a sustained increase in disability following a relapse.

Onset: Transitioning from CIS to RRMS

For a formal diagnosis of multiple sclerosis to be made, a person must have evidence of inflammatory damage (lesions) that affect more than one region in the central nervous system. That damage also must occur at different points in time.

Someone with evidence of MS-like inflammatory damage that has only occurred once — which can be thought of as having a “first relapse” of RRMS — is said to have clinically isolated syndrome (CIS).

While CIS is often the first presentation of RRMS, it is not considered true MS. The transition to RRMS happens when CIS patients go on to experience further disease activity, either in the form of a new relapse or the appearance of new spinal cord or brain lesions.

However, some people with CIS may never experience any further disease activity and are never diagnosed with overt MS. Some RRMS patients are never diagnosed with CIS because they already meet the criteria for clinically definite MS at the time of their initial diagnostic workup.

Symptoms of RRMS

RRMS is marked by relapses where symptoms suddenly worsen. These attacks may last for days, weeks, or months. Between relapses, symptoms generally ease, though recovery after a relapse is not always complete — symptoms may persist or linger after a relapse.

As in other MS types, symptoms of RRMS vary greatly from person to person depending on which parts of the nervous system are affected. People with RRMS are less likely than those with progressive forms of the disease to experience problems with walking and mobility. The most common RRMS symptoms include:

• fatigue
• numbness or other unusual sensations
• vision problems
• spasticity
• bladder and bowel issues
• cognitive difficulties and emotional challenges

How long does RRMS last?

Multiple sclerosis is a lifelong disease; its course varies substantially from person to person and is influenced by factors such as treatment, as well as demographics, lifestyle habits, and biology.

When left untreated, RRMS eventually progresses to a more severe disease form called secondary progressive MS (SPMS) in which symptoms gradually worsen over time irrespective of relapse activity.

The timing for this transition is different for everyone, but it’s estimated about 90% of RRMS patients would progress to SPMS within 25 years without treatment.

However, most patients today receive some form of disease-modifying treatments (DMTs) that reduce relapse frequency and slow the progression of disease. These modern medications also can drastically delay the onset of SPMS, with an increasing number of patients now going their entire lives without ever progressing to SPMS.

A study involving more than 15,000 RRMS patients, most of whom had received at least one DMT over their disease course, found that one in 10 patients transitioned to SPMS after a median of more than three decades.

Diagnosis of RRMS

There is no single test to diagnose RRMS. The diagnostic process generally involves a review of a person’s medical history, alongside physical and neurological examinations, such as a lumbar puncture or MRI scans.

These tests are used to identify signs of inflammation and nerve damage characteristic of MS, and also to rule out other conditions that may cause symptoms similar to MS.

According to the McDonald criteria — a set of guidelines to speed the diagnosis of MS, last revised in 2017 — an individual may be diagnosed with relapsing-remitting MS if they show clear evidence of inflammatory neurological damage that meets two diagnostic criteria:

• dissemination in space, meaning lesions are present in more than one part of the central nervous system (comprised of the brain and spinal cord)
• dissemination in time, meaning the damage has occurred at multiple points in time

Someone who has experienced two or more relapses, with evidence of lesions in multiple parts of the central nervous system, may be diagnosed with RRMS. However, if the person only experienced one relapse, and/or has evidence of damage in only one area of the central nervous system, the criteria are not met and a formal diagnosis of RRMS cannot be made.

Women are up to three times more likely to be diagnosed with RRMS than men. The diagnosis is usually made earlier, when patients are in their 20s and 30s, than in progressive types of MS, which are usually diagnosed when people are in their 40s and 50s.

Treatment of RRMS

There is no cure for RRMS. Treatment of this relapsing form of MS typically involves the use of DMTs, which have been proven in clinical trials to reduce the risk of relapse and slow the rate of disease progression. DMTs approved in the U.S. to treat RRMS include:

• Aubagio (teriflunomide)
• Avonex (interferon beta-1a)
• Bafiertam (monomethyl fumarate)
• Betaseron (interferon beta-1b)
• Copaxone (glatiramer acetate injection)
• Extavia (interferon beta-1b)
• Gilenya (fingolimod)
• Kesimpta (ofatumumab)
• Lemtrada (alemtuzumab)
• Mavenclad (cladribine)
• Mayzent (siponimod)
• mitoxantrone
• Ocrevus (ocrelizumab)
• Plegridy (peginterferon beta-1a)
• Ponvory (ponesimod)
• Rebif (interferon beta-1a)
• Tecfidera (dimethyl fumarate)
• Tysabri (natalizumab)
• Vumerity (diroximel fumarate)
• Zeposia (ozanimod)

These medications may be taken alongside rehabilitation approaches and other supportive therapies that help ease specific symptoms, such as fatigue, nerve pain, spasticity, bladder issues, and vision problems, that can carry a significant burden to patients.

Also, if a patient experiences a severe relapse, inflammation-suppressing therapies may be given to help resolve symptoms and induce remission more quickly. These therapies include:

• Glucocorticoids
• Adrenocorticotropic hormone (ACTH)-based therapies
• Plasmapheresis (plasma exchange)

Outlook of RRMS

The prognosis of relapsing-remitting MS varies markedly from person to person. Among other factors, it depends on the number of relapses a person experiences and the degree of recovery from these periods of worsening symptoms. Generally speaking, more frequent relapses with poorer recovery lead to a faster accumulation of disabling symptoms in people living with RRMS.

After someone is diagnosed with RRMS, it’s recommended they talk to their healthcare provider about developing a treatment strategy to manage the lifelong disease and delay conversion to SPMS, which tends to have a more severe disease course.

In addition to medications to ease disease progression and manage symptoms, this may involve lifestyle adjustments including quitting smoking and physical or occupational rehabilitation to improve function in day-to-day life.

Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.