I read on the MS website:

“Low risk of developing MS: When CIS is not accompanied by MRI-detected brain lesions, the person has about a 20 percent chance of developing MS over the same period of time”.

How can that be?

What if the neurological symptoms were caused by an infection or another disorder that is not linked to MS (e.g. vitamin d/b12 deficiency)?

I was tested with brain and spine MRIs, as well as with two evoked potential tests (i.e. all tests were normal), and was told that it is really unlikely to be MS-related (i.e. in my case a viral infection was suspected, even if nothing confirmed that), and now I see that in fact I could well be in that 20 percent category? The way I previously understood it was that no MRIs evidences potentially put you in the box of the 5% percent of people with MS that don’t have lesions, but not in the 20% box of people who may subsequently develop MS…

Also, the MS society defines a CIS as monofocal or multifocal (i.e. one or more lesion present on MRI scan), so how can someone who present neurological symptoms without MRI evidences be put in the category of CIS?

Any clarifications or insights would really be welcomed!

Blue Marble

When I received my original CIS diagnosis I had been experiencing tingling, pins and needles and loss of feeling in my left side. These symptoms had faded after about 8 weeks and certainly by the time I was seen by the neurologist. An MRI had already ruled out a disc problem, but too many nerves were involved for that to have been the cause anyway. I was told that the best diagnosis was of CIS, probably due to an inflammatory myelitis. The clear MRI indicated that I was low risk for further episodes (I was told it was about a 10% risk) and was advised that even if I had a positive l.p at that time it would only have increased my risk but not made me eligible for further treatment.

As I said on my other reply to you, scan evidence isn’t necessary when the symptoms are classic. Personally I feel that CIS is a bit of a woolly cover-all diagnosis but if you are lucky you probably won’t have any further symptoms. If all of your results have come back clear I would take that as a good sign and try not too worry unduly. If MS is at the root of the problem then it won’t stay hidden indefinitely.

I do not know the technical answer to your question. Here is my own experience back in 1999, before the term CIS was invented (as far as I know) - not sure whether this might help?

My first visit to the neurologist happened when my first relapse was just starting to resolve. He didn’t order an MRI, he just examined me and took a careful history. The follow-up six weeks later confirmed what he had expected: everything was back to normal, more less. I said I was worried about MS; he said there was clear clinical evidence of demyelination, but that it was a single episode, not multiple episodes, so by definition I didn’t have multiple sclerosis; the best thing was to forget about it and hope that it would never happen again.

In modern terminology, what I had then was CIS, no question, and that was plain as day to his eye from history and clinical exam alone - he didn’t need an MRI to tell him that there was demyelination. He even drew me a diagram of the cervical spine to show me exactly where the offending demyelination would be.

Sad to say, I was back in his consulting room a couple of months later with double vision. The second episode did trigger my first MRI scan, and that plus the earlier history sealed the MS deal pretty quickly.


Hey Alison, thanks for your testimony. In my cases, symptoms have been really diverse and generalised for about 4 months before progressively resolving, but again mine may have been triggered by something viral or infectious (as it started with a localised rash looking like a shingle a bit), even by vitamin D severe deficiency (which I have been correcting since then), so hopefully it was a one off…

If I may ask, what were your original symptoms, and how are you doing now?

By contrast, mine were defined and specific - sensory (numbness and disordered sensation that spread over a couple of days until it included most of my lower half but had really clearly-defined edges) plus motor (weak left hand - couldn’t hold a fork when it was at its worst). A few weeks later, it was all OK, more or less. I think those are the kind of things that help make a person relatively easy to dx.

I’m doing fine, thanks - still ducking and weaving. 10 years on Avonex and on Tysabri for the past 6. A few wheels on my waggon, still. I would have been glad to hear, back in 1999, how well and able I would be now.

I hope you soon get more clarity about what is amiss with you.