#MSCOVID19 Does COVID-19 trigger relapses?


It is known that viral infections can both cause relapses and worsen existing MS symptoms – why should COVID-19 be any different?

This study used the UK MS Register COVID-19 study, where people with MS can self-report both COVID infection and MS related information. By asking people with symptoms suggestive of COVID-19 about their MS symptoms, we were able to try to estimate the impact of infection on MS.

Of the 978 people who had reported COVID-19 symptoms, 404 provided information about their MS. These people had had MS for an average of 11 years, and most of them had some MS-related disability prior to getting COVID-19. About half were taking a DMT – and the DMTs taken were spread across the full range. 8 people were hospitalised as a result of their COVID-19 symptoms.

Over half of the people taking part in this study – 230/404 reported new and/or worsening MS symptoms during their infection. 82/404 people with COVID-19 developed new symptoms, and 207/404 had worsening of existing symptoms. This means that 59/404 (or 15%) had both new symptoms and worsening of existing symptoms. Almost everyone with worsening of their MS had a fever during their COVID-19 infection, compared to ⅔ of those with COVID-19 but no change in MS. 77/196 (39%) of those with an MS exacerbation required additional support during their infection, as opposed to 7/114 without an MS exacerbation.

The most common new symptoms were weakness and sensory problems. People taking a DMT were less likely to get new symptoms. Pre-existing symptoms were more likely to worsen in those with higher EDSS and longer MS duration.

There has been a lot of concern around DMT use in the current pandemic. However, this study shows that people taking DMT are substantially less likely to develop new MS-related symptoms if they are unlucky enough to get COVID-19. When this is taken alongside the wealth of studies that show that most DMT are not associated with more severe COVID-19, the message seems clear, if you are eligible for DMT then don’t delay because of the current pandemic.

The apparent association between fever and worsening of MS symptoms is not surprising, we know that this happens in other viral illnesses, and that fever (or anything else that raises core temperature) can slow nerve conduction, particularly in demyelinated axons. However, this is temporary, and should not lead to lasting worsening of MS symptoms.

Of course – prevention is better than cure and if you are offered vaccination then please take it up.

Most people do not get significant fever or worsening of symptoms from the vaccine and if you do this is likely to be temporary, and lead to less long-term problems than a significant relapse resulting from COVID infection. We are currently trying to look at vaccine responses, so if you are under the care of BartsMS and want to take part in our study (which doesn’t require any hospital visits, but does require fingerprick blood samples), please let us know by email – mscovid19ab@qmul.ac.uk


COI: I am an author of this Preprint

COVID-19 is associated with multiple sclerosis exacerbations that are prevented by disease modifying therapiesAfagh Garjani, Rodden M Middleton, Rachael Hunter, Katherine A Tuite-Dalton, Alasdair Coles, Ruth Dobson, Martin Duddy, Stella Hughes, Owen R Pearson, David Rog, Emma C Tallantyre, Roshan das Nair, Richard Nicholas, Nikos Evangelou medRxiv 2021.03.08.21253141; doi: https://doi.org/10.1101/2021.03.08.21253141

Background: Infections can trigger exacerbations of multiple sclerosis (MS). The effects of the coronavirus disease 2019 (COVID-19) on MS are not known. The aim of this study was to understand the impact of COVID-19 on new and pre-existing symptoms of MS.

Methods: The COVID-19 and MS study is an ongoing community-based, prospective cohort study conducted as part of the United Kingdom MS Register. People with MS and COVID-19 were invited by email to complete a questionnaire about their MS symptoms during the infection. An MS exacerbation was defined as developing new MS symptoms and/or worsening of pre-existing MS symptoms.

Results: Fifty-seven percent (230/404) of participants had an MS exacerbation during their infection; 82 developed new MS symptoms, 207 experienced worsened pre-existing MS symptoms, and 59 reported both. Disease modifying therapies (DMTs) reduced the likelihood of developing new MS symptoms during the infection (OR 0.556, 95%CI 0.316-0.978). Participants with a higher pre-COVID-19 webEDSS (web-based Expanded Disability Status Scale) score (OR 1.251, 95%CI 1.060-1.478) and longer MS duration (OR 1.042, 95%CI 1.009-1.076) were more likely to experience worsening of their pre-existing MS symptoms during the infection.

Conclusion: COVID-19 infection was associated with exacerbation of MS. DMTs reduced the chance of developing new MS symptoms during the infection.

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  • What does this mean for people who have had and IRT? Are they in the same boat as those who do not take any medication?

    • we didn’t really have enough people on any one medication to look at differences according to DMT – but IRTs were included as “on medication” – we know that the effect of these medications last longer than the time that you take them for (if that makes sense)

  • A few questions

    In your preamble you mention relapses and the paper talks about exacerbations. As a pwMS I find it difficult to classify the difference in my symptoms day to day. This is even before we introduce the smouldering MS concept. I am relatively new to the world of MS but I thought that there was a doubt about infection triggering relapses.

    I can identify 3 incidents in my life that I would say were relapse like. The first was over 50 years ago at around 13 when I had a bout of what was termed Glandular Fever. My GP said I was fit to go back to school but I would have been unable to walk the couple of miles that were necessary. The second was weakness after a viral infection about 4 years ago which left me tripping over etc. This was retrospectively taken to be my first MS relapse. I was actually diagnosed in a day about 3 years ago and I do not recall any illness before. My GP was unable to work out why an apparently fit 60 year fell over on the way into his office. I was sent to the ambulatory care unit of the county hospital. The MRI test was looked at remotely by a neurologist who directed various blood tests.

    Now the first question: how easy is it for a neurologist to classify what is an exacerbation and what is a relapse and does an MRI help or hinder this?

    The second concerns the Odds Ratios: I have not fully got my brain round these yet, in this case has the sample been divided into groups or is it scaled on years since diagnosis? If so how as the sample been categorised?

    Good to see output from the MS Register.

    • I could have written this myself. I have no idea what have been relapses/exacerbations, and what is day to day stuff which is pretty much always around and changeable for me since I was diagnosed 1.5 years ago 🙈

      In speaking with Ms nurses they seem to say any ‘new’ symptom that lasts longer than 2 days, in the absence of any systemic sickness or stress could be a relapse, I think in rrms an enhancing lesion on an mri with contrast would evidence this, but they don’t stay enhancing for long, so a new lesion or a change in lesion load after the fact might confirm this as a relapse? I think any increase in symptoms with tiredness / sickness/ stress is an exacerbation….
      Then to confuse matters o read about ppl talking about ‘break through’ disease on a drug, I’ve no idea what this means, should we not be symptomatic on drugs? If we are are they failing? 🤷🏻‍♀️🙈

      • It can be really difficult to tell relapse from exacerbation – particularly when doing everything remotely, and people are feeling ill from COVID/other infection. This was partly why we decided to look at both, and indeed there were a number of people with both. MRI can help to look for people with new lesions – but its not perfect. But the perfect test sadly doesn’t exist (yet!).

        Re. odds ratios – we divided into groups, and then statistically “corrected” (i.e. took into account) other factors that might impact. some things we did as yes/no (such as DMT use), and others looked at as continuous – e.g. age (but this is similar to years from diagnosis, so need to be a bit careful).

  • Thanks for this post.
    Any follow as to whether the symptoms evidenced during the infection (new and exacerbation of existing) continued once the PwMS were well again?
    Any information emerging concerning PwMS and Long Covid?

    • we are still collecting information about exactly this, so watch this space! I think the LongCOVID information will come, but it will take time.

  • shows that people taking DMT are substantially less likely to develop new MS-related symptoms if they are unlucky enough to get COVID-19

    So this could sugest that covid-19 its an immune mediated disease?

    Nice post

    • it was in the news today that covid is causing ebv reactivation my partner was tested and diagnosed with glandular fever just after we had covid i wasn’t tested for ebv at the time i wish i was because strangely it was the exact same time as my first relapse that put me in hospital and got me diagnosed there has to be an immune mediated link !!!

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