In 2013, the International Advisory Committee on Clinical Trials developed an updated description of the different types of MS, based on advances in the understanding of the disease process and MRI technology.1

In 1996, the National MS Society (NMSS, U.S.) Advisory Committee on Clinical Trials in MS defined the clinical subtypes of MS. This Classification was consensual and was a standard MS practice and clinical research regarding clinical types of MS but imaging and biological correlates were missing.2

The Committee agreed in classifying MS with 4 main types:

Clinical Isolated Syndrome (CIS)

Relapsing-remitting MS (RRMS)

Secondary progressive MS (SPMS)

Primary progressive MS (PPMS)

Clinically Isolated Syndrome (CIS): is a first episode with neurologic symptoms caused by inflammation and demyelination in the central nervous system — which must last at least 24 hours — but does not yet meet the criteria for a diagnosis of the disease. Sometimes, people who have a clinically isolated syndrome will not go on to develop MS. An MRI will better determine the likelihood that someone who has a CIS will develop MS. If lesions on a brain MRI are seen with CIS, there is a higher chance of developing MS.

Relapsing Remitting Multiple Sclerosis (RRMS):  This is the most common form of MS with clear defined phases of relapse (repeat attacks or exacerbations), with progressive worsening of nerve functions with each attack, followed by phases of relief (or remission) where normal conditions are restored partially or completely. RRMS defines in 85 percent of all cases.

Primary Progressive Multiple Sclerosis (PPMS):  This represents a condition with steady progression without early relapses or remissions, and temporary periods of stability. There can also be increasing periods of disability for the patient, either with or without new relapses or MRI lesions. PPMS develops in about 15 percent of MS cases.

Secondary Progressive Multiple Sclerosis (SPMS): This follows RRMS, with continued relapses and progressive neurological damage. Most patients will eventually transition to a secondary progressive course, with worsening of nerve damage, with or without remissions. It can be characterized as either active or not active, and with progression or without progression. Disability gradually increases over time during this course.

Relapsing MS is a term occasionally used to cover both RRMS patients and those who have progressed to SPMS but are actively having relapses.


Note: 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.

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  1. Wife has severe MS. They hit her with a trial. The doctor started her off with Chemotherapy, a drug used for breast cancer called Cytoxan. The idea was to knock out her immune system and rebuild it. She was progressing very very fast all of the sudden. Went from a cane, to a walker, to a wheelchair and diapers within a month after years of taken many MS drugs. The therapy started with 1/2 a gram of Cytoxan for about a month, then the doc decided to up the dose to a gram. That night she had a major seizure. While she has progressed since, it is not as severe and seems to have subsided. While nothing really got better, she has since lost the ability to communicate/speak and has no emotion, it does seem to have helped although she never “Finished” the treatment, and I do not know if it included rebuilding with stem cells which I have read they are now trying. All I can say is I am happy to still have my wife around, if nothing was done, I do not believe she would still be here with us and while I say she has no “feelings” she does seem happy 99% of the time. I do not see any depression or anger which is amazing. I do believe the treatment should be explored more and a gram of Cytoxan for someone who is 4’9″ and 110 lbs is too much …

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