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Hello, and welcome to Episode Twenty-three of Multiple Sclerosis Discovery, the podcast of the MS Discovery Forum. I’m your host, Dan Keller.
This week’s podcast features an interview with Professor Aksel Siva about radiologically isolated syndrome. But to begin, here is a brief summary of some of the latest developments on the MS Discovery Forum at msdiscovery.org.
The role of diet in MS is a longstanding question, for which there many opinions, but few definitive answers. Researchers and clinicians know little about how diet may contribute to the risk of developing MS, and how it may help or hurt the progress of the disease once it starts. Nevertheless, patients are pushing for answers, hoping that there is more they can do to help slow their disease. We recently published a story looking into all the facts and myths of diet. We also covered what makes diet so difficult to study in a clinical setting, and where the field is going from here.
2015 is just around the corner, and deadlines are looming for submitting meeting abstracts and funding applications. Abstract submission deadlines for the Keystone Symposia are coming up in December, and ECTRIMS and the National MS Society have deadlines for funding opportunities early in January. For more details on the deadlines and how to submit your materials, go to the professional resources tab on our website and click on either “meetings and events” or “funding opportunities.”
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Now to the interview. Professor Aksel Siva is a professor of neurology at Istanbul University in Turkey. His work spans areas from clinical neuroimmunology to neuro-epidemiology to research in headaches.
Interviewer – Dan Keller
When we met he discussed radiologically isolated syndrome or RIS and he starts by describing what it is.
Interviewee – Aksel Siva
It is by definition an individual who gets an MRI for another reason such as migraine headache or whatever. Then, it turns out that they have MS looking like lesions in their brains. You cannot explain those lesions with any other pathology. They are not related to the patient's cause of referral for an MRI. Their neurological examination is normal, and these people never have experienced any neurological symptom, which might be consistent with past history of MS whatsoever.
It is an MRI diagnosis actually. It is not a clinical diagnosis. The question is whether these people do really have subclinical MS or asymptomatic MS and are they going to develop the disease. So the question is what to do when you see these patients. And this has been recently described as radiologically isolated syndrome by Okuda et al. At that time, there were acute CSF and now Darin is in Texas and at that time his mentor Daniel Pelletier is at Yale. So they have introduced this term. There have been, I would say, three pivotal papers by the French group, Christine Lebrun and her colleagues, and from our center together with Mayo Clinic in Rochester. Then this group came together and we have formed the Radiologically Isolated Syndrome Consortium, which has been later on joined by some other centers from Europe and the U.S.
MDSF
So if you don’t know whether these people will go on to MS or where they stand, what do you do about it? How do you follow them and how many of these people do go on to MS?
Professor Siva
The Radiologically Isolated Syndrome Consortium, we have conducted a study, which was published earlier this year in PLoS ONE and we have collected 451 cases with this syndrome. When they were followed, about 34% developed a neurological event consistent with either CIS or primary progressive MS. This means that about one-third of these people, who receive a diagnosis of radiologically isolated syndrome, in five years’ time, will develop clinical MS. And 10% of this group will develop primary progressive MS, which is very similar to what we see in two clinical cohorts. When statistically you follow these up to ten years and this is statistical, it turns out that around 55% will develop the disease. So at ten years’ time, still half of these people will not develop clinical MS. What does this mean? It is not clear, but on the other side, it seems that some people, who do have radiologically lesions consistent with multiple sclerosis and may continue to get new ones, still will not the clinical disease. We have known this from some autopsy studies started to be published in the 1960s, 70s, 80s, that there were cases, autopsy cases, where people turned out to have changes in their brains consistent with multiple sclerosis, but they never had the disease in their lifetime. We have to consider this subpopulation in both understanding the disease and when we should consider to start treatment, or whether we should really treat all people with MS or not.
MDSF
There has been a feeling that you don't treat the image, but you treat the disease, but a lot of these people do go on to get the disease. Is it time for a randomized trial to see if you treat these people, some of them who would statistically go on, will not go on to get the disease?
Professor Siva
It is time to start a treatment trial in RIS and our EOS colleagues, mainly Darin Okuda and Daniel Pelletier and Orhun Kantarci will be starting such a study in the U.S. later this year. There is also another probable trial that might start in Europe by Christine Lebrun. Yes we have come to this era, and probably within let's say a few years, we will have more evidence regarding who should be treated or who should not be when they present with RIS.
MDSF
In the study that you looked at people for five years, what did you see were some of the risk factors for going on to MS?
Professor Siva
There were some clear-cut risk factors and this was, as already shown by Darin and their group in EOS [?] a couple of years ago, having a spinal cord lesion at the time of the RIS diagnosis is a predictive factor to develop MS. Other factors are male gender and younger age; because when we have looked in this RIS cohort of the 450 or so cases, the mean age of diagnosis was 37, which is older than the general mean age that we diagnose MS. So this should be also taught whether this is because we have just by coincidence we get these incidental lesions in some people who will never develop the disease.
MDSF
Now this study started a while ago to be able to be published recently. In that amount of time people have been looking at a lot of biomarkers. Did you consider biomarkers at that time? Can you find something that is predictive of going on to MS?
Professor Siva
Not yet. Actually this study was a retrospective study, but in part it was prospective because in our center we have been interested in this for more than ten years now, almost 15 years. I should say that in Turkey we have a lot of MRIs and the cost is very low. It is very practical for, let's say general neurologists to refer patients for headaches, for not otherwise you would refer for a MRI, to refer them to MRIs, and then suddenly you started to see this MS looking-like lesions. As we have in MS center, we had a lot of referrals and then we started to follow these people. It’s been more or less the same in the other centers. It is yes, a retrospective data collection, but most of this cohort has been prospectively followed in those centers from the time of their admittance. And your question was whether there was a biomarker other than imaging, not really. Not yet, let's put it that way.
MDSF
So is it advisable to follow them with imaging and if so, how often?
Professor Siva
It is what we are doing now. There have been some suggested algorithms, but what we do in our center, we ask those patients to have a followup MRI in six months. Then within another six months, unless they develop something clinical, and then if they continue to have changes or not in their MRIs, that depends on how frequently we start to follow them up by MRI. Our tendency is twice for the first six months and then yearly for the next two years and then three years or two years later, unless they develop a clinical event consistent with MS or whatever.
MDSF
Necessarily these interval MRIs are really snapshots, even in MS lesions come and go. I suppose it would be possible to miss a lesion that was there and that isn't there at the time of the MRI.
Professor Siva
Definitely. But it has been shown, again in our study, that about two-thirds of these people continue to have new MRI lesions, but only one-third of the whole population develop a CIS or other event consistent with MS. Having new lesions doesn't really mean that the risk is much higher. Developing new MRI lesions is not always equal to develop the disease or having a much higher risk. It has been shown by the Queen Square Group many years ago when they have followed people who were admitted with CIS for up to 20 years. Ten to 15 % of these populations who presented with CIS, mostly optic neuritis continued to have new lesions, but they never developed a second clinical attack. It is more or less, I believe, for RIS some of those people will continue to have maybe one or two lesions when you do a followup MRI, but that doesn't mean that they necessarily will develop the disease. Even having positive oligoclonal bands is not a much higher risk by itself.
MDSF
It would be quite a burden to treat 100% of the RIS population to be able to avert a progression to MS in about a third or over ten years about 55%. I guess, what you really need to do is be able to figure out who will progress. I guess a subpart of that question is, how do you know, or do you know, who will go on to primary progressive MS?
Professor Siva
Well we cannot say this when they don't have any clinical symptoms and signs, because in our center we had three such patients who developed primary progressive MS after a period of four to eight years, when we have followed them radiologically. Probably another question is, whether all primary progressive MSs are really primary progressive, or are let's say secondary progressive MS, the diagnosis was done when they have gone through all of the let's say CIS, relapsing-remitting MS subclinically, and when they have entered in the secondary progressive phase, then, the disease became clinically surfaced and because of this we thought that this was people who were primary progressive. Because when you look at these people and we had those…well the whole group, the RIS we have more such cases, which is now prepared for publication. These people continue to have new lesions and they are not really any different than the relapsing-remitting cases. This is another issue that we should consider.
MDSF
So in essence asymptomatic MS might really be MS and what looks like primary progressive is really secondary progressive.
Professor Silva
Could be. That is a possibility. If I am not wrong, it was the late Charles Poser who had suggested that a number of MS patients the disease goes subclinically for a certain period of time, but they continue to have axonal degeneration and after a certain threshold they become only clinically symptomatic. It might be an analogy between this view and what we have observed.
MDSF
Is there anything important to add on the subject of RIS?
Professor Silva
Our approach is on an individual basis. Yes, we do have some evidence, we do have some findings, but that doesn't mean that when you see an individual with RIS they will do how it is expected according to the present evidence. When I am with my patients, or I shouldn't call them patients, but the individuals with RIS, my approach is on an individual basis. If they continue to have new MRI lesions and it is really high T2 load on the MRI, we ask for a CNS study, if they have positive oligoclonal bands, they have but normal visual evoked potentials; they have family members and so on. The way I approach those individuals is a little bit different than someone who has a few lesions, just enough to make a diagnosis of RIS, but don't have really other risk factors, no spinal cord and so on. When it comes to the patients we should make our decisions on an individual basis. I do not treat people RIS, but there might be some exceptions.
MDSF
Very good, I appreciate it.
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Thank you for listening to Episode Twenty-three of Multiple Sclerosis Discovery. This podcast was produced by the MS Discovery Forum, MSDF, the premier source of independent news and information on MS research. MSDF’s executive editor is Robert Finn. Msdiscovery.org is part of the non-profit Accelerated Cure Project for Multiple Sclerosis. Robert McBurney is our President and CEO, and Hollie Schmidt is Vice President of Scientific Operations.
Msdiscovery.org aims to focus attention on what is known and not yet known about the causes of MS and related conditions, their pathological mechanisms, and potential ways to intervene. By communicating this information in a way that builds bridges among different disciplines, we hope to open new routes toward significant clinical advances.
We’re interested in your opinions. Please join the discussion on one of our online forums or send comments, criticisms, and suggestions to editor@msdiscovery.org.
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