Radiologically Isolated Incident

HI - I know this topic is being discussed in another thread, but the title of the other thread was called somehing completely different, and i wasnt sure if people would notice this bit, so i thought i’d start a new one thread , as i’m really curious and would appreciate others knowledge & input about this.

So - as far as i understand it, multiple sclerosis is when there is compelling evidence of multiple attacks, whilst clinically isolated incident is when there is only sufficient evidence to be sure of one isolated attack.

So what is Radiologically Isolated Syndrome, and how does it differ from Clinically Isolated Incident.?

If you google RIS, you find that it apperantly refers to lesions on an MRI that are ‘highly suspicious of MS’, but were found unexpectedly and incidentally (for example, if a patient is having MRI for another reason), and the patient is not experiencing symptoms of MS. Different studies show slightly different results, but there is (apperently) about between 25 and 50% chance that a patient with RIS will ‘convert’ to MS within 5 years, and possibly this conversion rate increases after 5 years. It was once thought that RIS represented ‘asymptomatic’ MS, but some authors say that they now believe it represents ‘presymptomatic MS’.

BUT - here’s what’s causing me confusion - the lesions on my mri were not found ‘incidentally’ at all … they were found during investigations for MS. Also, I wouldnt say that I’m entirely asymptomatic… or even presymptomatic… I have episodes of fatigue, chest pain (MS hug?) , spacticity (take baclofen) and constant pins& needles in my leg.

As i said in the other thread, I wasn’t assessed at the time of my original first ‘event’, sothe neuro obviously can not objectively confirm it happened, and my physical exam only showed minimal problems. I was wondering if this was what had led to being diagnosed RIS not CIS - that there is evidence on mri that ‘something’ happened, but not enough evidence elsewhere of there being any one specific ‘incident’ to tie it to. But this is all supposition on my part - really i am not at all sure!

The last letter I had from my neuro said that “so far there is not enough evidence for diagnosis of RRMS, so I think for now we are dealing with a radiologically isolated syndrome.” and “I am suggesting further scans to see if any more lesions are coming through, and a lumbar puncture might also be useful at this point”.

So I know investigations are ongoing (my neuro is actually very nice), and I mostly feel not too stressed about being in limbo - if further lesions show, I may get MS diagnosis, which in some ways would give clarity, but if not, then I am trying to see it as a good thing, because it means I’m not progressing.

But - I’d still be interested to hear from anyone else who was diagnosed wirh RIS not CIS - because my diagnoses was definitely not made ‘incidentally’, as is meant to be the case. Also, the originator of the other post had also discussed RIS with their neuro - (I’m not totally sure of their circumstances, but think they might also have been having investigations for ms, so, if i’m right, in their case, findings on mri were maybe not ‘incidental’ either. So I’m clearly not the only one in this position.

Can anyone shine a light on this / share experiences?

Many thanks x

Hi Anon,

Was following this in the other topic.

I’m new to the concept of RIS, as distinct from CIS, but your explanation - albeit only a guess - makes sense to me.

If there is no objective evidence - or only negligible evidence - of neurological impairment - only patient’s self-reports, it may be why it can only be formally recorded as a radiological finding, not a confirmed CIS.

My own self-reports of previous episodes were NOT accepted as evidence for the purposes of diagnosis, although there was never any suggestion I was mistaken or lying - just it hadn’t been clinically verified, so it couldn’t be taken as established fact. Interestingly, though, my own self-reports of earlier episodes were accepted for the purposes of determining eligibility for DMDs. It seems slightly anomalous that they can’t be accepted as diagnostic evidence, but are OK as eligibility evidence - although perhaps that depends on the neuro. I suppose once the patient has clinically verified MS, there is no reason to doubt their accounts of earlier episodes, even if these weren’t medically attested-to.

I can only assume you are in a similar position. Nobody doubts what you’re saying, but because there’s no clinical evidence (or very little) in support of it, it can’t count towards a diagnosis.

I had to hold on for new MRI evidence, even though I could describe and give approximate dates of at least two previous episodes, so if that had been acceptable, I would have satisfied “dissemination in time” much earlier. I guess it is the gap between what the patient knows, and what the neuro is able to prove.


Hi Anon 22 Dec 2013 at 9:50AM,

Your description of RIS-CIS matches what I had picked up too. That CIS is one symptomatic attack and RIS is asymptomatic with only MRI evidence. If it is presymptomatic then it is still asymptomatic . i.e. there are no symptoms yet. Whether it is presymptomatic will only be shown if symptoms do develop. So - I think RIS is asymptomatic; and may later prove to have been presymptomatic. If it proves to have been presymptomatic it aso bcomes part of MS.

I’m wondering if your neuro meant CIS as you do have symtoms; or are they attributed to some other cause than MS?

Hi Vithari -

This is why its confusing me!! I do have symptoms (pins and needles, pain, spacticity), which is why I was referred to neuro - to ‘rule out’ MS. mri was done and lesions found. then neuro said RIS - which, as you say, means ‘found incidentally’ and ‘not causing symptoms’. But they were not ‘found incidentally’, and I do have symptoms! It has me baffled!

Everything else ruled out - all the usual blood tests etc. I do have a history of mental health difficulties but that wouldnt cause lesions, and I don’t think that that is the cause of my symptoms (although i guess until another cause is determined, I wouldn’t rule it out completely).

I guess I could just ask my neuro directly about why I was diagnosed RIS rather than CIS. But I am sure he knows his stuff and I’m sure there will be good reasons, I just dont know what they are! also he clearly has loads of patients to see, and I feel it would be wasting his time at this point, because probably wont make any real practical difference to my situation anyway. I have had more scans and have been offered LP - so, if it does transpire to be MS, than something will show - and if nothing else shows, I guess it is not MS, and that’s the bottom line really. They will reassess me if anything else happens, and I don’t really see what more I could ask for than that.

thanks all… just talking it through has helped. The RIS / CIS diagnosis It is still a bit confusing to me, but nothing to get my knickers in a knot over x

I am the same, i have had symptoms for 13yrs and i have had 2 brain mri’s in the past which showed nothing but i had one 6 months ago because of vertigo, fatigue etc and lesions were found on this one. I had a LP 3 months ago which was negative and now waiting for an evoke potential test. The neuro mentioned RIS but like you the lesions weren’t found by accident so i am confused. All the tests i have are normal or negative apart from brain mri showing lesions. I have had ongoing symptoms for 13yrs and i seem to have relapses and then get a bit better again and it’s been like this from the start.

Hi Zipster x

It is reassuring to know i am not the only one in this position.

When I was told RIS, i initially honestly thought it meant the same thing as CIS … for ages I thought the I had been diagnosed with CIS - it was only recently I discovered they are two different things (silly me!).

One thing that occured to me today was about the ‘incidental’ findings bit…

I was being screened for MS due to a suspected optic neuritis and also chest pain (MS hug?) and tingling / stiffness in leg. But neither my brain MRI or evoked potentials showed up any evidence of ON, although it did show up lesions elsewhere in the brain. BUT… both neuros I have seen have said that whilst these particular lesions are ‘suspicious’ of MS, they would not account for the symptoms in my leg (which is why I have had further MRIs). So I guess in some ways I can see how the findings could be considered ‘incidental’ - they went looking for evidence of optic neuritis, but didn’t find any - but during the search, they found other lesions. So now I have a certain set of symptoms, and also some lesions, but the two don’t necessarily tie in together (correlation does not always equal causation?)

I am trying to be as philosophical as possible about it all, and am mostly succeeding (I hope). I am trying to trust that they do know their stuff and they have good reasons for their decions (even if I don’t understand them!). For me, I think that it is really important not to second-guess the experts too much, mainly because I think that just makes me angry and frustrated - so I have resolved as far as possible to follow what the test results show and to trust what the experts say. In fact, some ways I find it reassuring that they won’t diagnose MS unless they are absolutely sure. But then I’ve only been under investigation for 2 years, not 14 ! Hope you get some answers soon x