RRMS and PPMS - A Comparison, Part II

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Only 10% of those who have MS are affected by the Primary Progressive type. I pointed this out in Part I, and today I am going to continue discussing PPMS by comparing it with Relapsing Remitting MS (RRMS). Let's start with the dreaded wheelchair.

Wheelchair Prognosis

What about walking? An MS diagnosis of any kind often brings with it a fear of wheelchairs. Almost everyone who receives an MS diagnosis immediately fears the possibility of being in a wheelchair. Leg involvement of some degree is experienced by MSers of all types, but only about 25% - 40% actually use wheelchairs on a regular basis.

For PPMS, wheelchair use is closer to 80%, but that is often over an extended period of time. Seven years after diagnosis, 25% of people with Primary Progressive MS need assistance walking (for instance, a cane). By the 25-year mark, up to 75% of the patients need assistance with mobility.

Gender Ratio

MS affects women more than men. At one time the gender ratio was 2 to 1. In recent years, that ratio has increased to 4 to 1. The reason for the increase is uncertain, but MS is generally considered a woman's disease.

Primary Progressive MS, however, has no such gender bias. Instead, the number of men and women with PPMS is close to equal.

However, the prognosis of PPMS is generally better for women than men. The number of relapses decrease during pregnancy, especially during the last trimester. Clinical trials have found there is generally no difference between genders taking different medications. There are, however, several small trials that do show differences.

In small tests, women with secondary progressive MS have shown slowed progression, and men with primary progressive showed a slow progression. There was no gender difference in clinical trials for relapsing remitting type.

Cognitive Difficulties

In RRMS , some MSers have difficulty with attention, memory, speed of thinking, judgment, and processing visual information.

In PPMS, Cognitive difficulties are less likely to occur because the disease is not centered in the brain. PPMS cognitive difficulties are similar to dementia in aging. Often the difference is largely a matter of time needed to process an activity. One study concluded those with RRMS process slower than those with PPMS and those with PPMS process slower than healthy control subjects.


Before the early 1990s, there were no disease-modifying drugs specifically for MS. Then Betaseron was approved by the FDA. There was soon a family of drugs for relapsing multiple sclerosis types. Avonex®, Betaseron®, Copoxane® -- and later, a fourth option -- Rebif®, were known collectively by their initials -- the CRAB drugs.

Novantrone®, a chemotherapeutic agent, and Tysabri® were soon approved, too. And Corticosteroids (commonly called steroids) are mainstay treatments for acute relapses. PRMS is included in the relapsing group so these medications are also valid for it.

PPMS responds poorly or not at all to treatment that seems to work for other types of MS. There are no drugs approved specifically for Primary Progressive MS, but many MSers with PPMS are prescribed medication that is approved for RRMS anyway. Copaxone® seems to be popular as a choice in this case.

There are alternative and complementary treatments available for all MS types. Some are valid and useful, but others may not be so useful or safe.


There is, as always, plenty of research for RRMS as illustrated in clinical trials.gov. Many trials are counted a success based on the reduction of the number of relapses.

For years there was little or no research specifically for PPMS. Those with PPMS ask "What about me?" Traditionally, PPMS research runs into obstacles that make it unpractical, such as the lack of identifiable milestones to measure success points. Also, PPMS progresses so slowly it makes for an extended trial length that is too long for participants.

Again looking at clinicaltrials.gov, we see research specifically for PPMS as well as inclusion in general trials.

Some of the trials specific to PPMS:

  • UTSW Med Ctr. comparing immune response of PPMS to RRMS; hopefully leading to effective treatment
  • Brigham and Women's Hospital in Boston, researchers are using novel imaging techniques to compare different parts of the brain in primary-progressive and other types of MS which could eventually yield new strategies for predicting and monitoring MS progression.
  • MS clinicians and researchers are actively looking for ways to increase the number of trials in PPMS

I researched this subject for better understanding, and I hope it helps to show the difference between RRMS and PPMS. It looks to me as if there is something positive happening for the future.

Understanding can overcome any situation, however mysterious or insurmountable it may appear to be. ~ Norman Vincent Peale