Last week I wrote a post about the new MS drug Ocrevus and used some acronyms that I didn't properly stop to explain. I apologize and will now try to explain the different types of Multiple Sclerosis, also known as MS.
Some Terms
Sclerosis refers to scarring on the brain and spinal cord, seen as lesions in an MRI (magnetic resonance imaging) scanner. Multiple refers to the fact that in this disease there will be more than one. (No duh, right?)
The mechanism of MS seems to work like this: for whatever reason, the body's immune system begins to eat away at the fatty insulation around the nerves in the brain and spinal cord, known as the myelin sheath, and hence the term demyelination to describe this scarring.
When this happens and the myelin is lost, the nerve can no longer effectively conduct electrical signals. And wherever that happens in the brain or spinal cord will affect what symptoms will be experienced. This is one of the reasons we say MS affects each person differently.
Disease Types
For the majority of MSers the first indication that something is wrong is when the first symptom flares-up, also known as a relapse, although technically I guess this first one could be called a Clinically Isolated Symptom because until it happens again, you can't have a relapse. Also, it may never reappear at all.
Anyway, relapses usually hold on for a short-ish period of time (from a few days to a few months) then resolve. Sufferers may remain symptom-free for periods of months or years (symptoms remit).
So RRMS stands for relapsing-remitting MS. According to the National Multiple Sclerosis Society (NMSS) about 80 to 85 percent of MSers are initially diagnosed with this type of the disease.
Eventually, RRMS may turn into secondary-progressive MS, aka (also known as) SPMS. According to the Multiple Sclerosis Association of America (MSAA) "…(t)his form of MS …has a slow, steady progression – with or without relapses. If relapses do occur, they usually do not fully remit." So type is secondary-progressive, flavors are with relapses and without relapses.
PPMS aka primary-progressive MS as described by MSAA: "Approximately 10 percent of the MS population is diagnosed with primary-progressive MS (PPMS), where individuals experience a steady worsening of symptoms from the start, and do not have periodic relapses and remissions." Here type is primary-progressive and flavor is without relapse.
Other "flavors"
Apparently, another "…5 percent of patients are initially diagnosed with progressive-relapsing MS (PRMS). This type of MS steadily worsens from the onset, but symptom flare-ups…are also present." So type is progressive but flavor is with relapse?
Also, according to MSAA:
- benign MS (with little or no change after 15 years; however, progression may occur at a later time)
- fulminate MS (a rapidly progressive disease course with severe relapses within five years after diagnosis; also known as “malignant MS” or “Marburg MS”)
- burned-out MS (term used to describe MS patients whose MS progression slows dramatically in later life)
I've also heard about MS in children.
So yes, it's complicated. And I do think doctors should be given a little slack, trying to officially diagnose you. Sometimes they will need to wait and watch to see how the disease will act over time. And although MS has been recognized since 1868, there is still no definitive test to prove or disprove whether you have it. But even just knowing the type of disease, is better than not having any kind of diagnosis, in my opinion.
Related resources
- What is MS? (NMSS)
- Multiple Sclerosis Overview (MSAA)
- Multiple Sclerosis (MS) in Children (WebMD)