Tag Archives: clinically isolated syndrome

Diagnosis, Stages of MS

Do I have active MS?

Before deciding to start a disease-modifying therapy you need to know if you have active MS.

Key points

  • To qualify for a disease-modifying treatment for MS you must have active disease.
  • Active MS is characterised by relapses (new symptomatic or asymptomatic lesions); the clinical diagnosis of relapse may be supported by MRI or CSF evidence of activity.
  • Different levels of disease activity qualify for different types of DMT.
  • Diagnostic criteria for MS have evolved considerably over the past two decades; this has helped to make treatment decisions earlier and easier, both for MS neurologists and for people with MS.

To be eligible for disease-modifying therapy (DMT) you must have ‘active MS’. This term is increasingly used to refer to current or recent evidence of focal inflammatory activity, i.e. new lesions on magnetic resonance imaging (MRI) or a relapse. Inflammation damages axons, or nerve processes. When a lesion develops, the effects of inflammatory mediators can cut (transect) axons, demyelinate them or stop them from working.

By contrast, the gradual worsening of disability that occurs in people with more advanced MS (which may, or may not, occur in the presence of focal inflammatory activity) has many potential causes, only one of which is focal inflammation.

Signs of active MS

Relapses

When a new MS lesion occurs in an eloquent part of the central nervous system it causes new symptoms or exacerbates old ones – this is usually interpreted as a relapse. Relapses, by definition, last at least 24 hours in the absence of infection or fever.

Criteria for ‘active’ MS accepted by many MS health professionals. CSF, cerebrospinal fluid; NFL, neurofilament light.
*Some neurologists accept 24 months, 36 months or even more when assessing MRI activity. There is no international consensus on the gap between the baseline and new MRI scan to define active disease.

Asymptomatic lesions

Most focal MS disease activity does not cause any overt symptoms because the brain has a way of compensating for damage. For every clinical relapse, there are at least 10 or more lesions on MRI. Therefore, what we see clinically in terms of relapses is the tip of the iceberg. Even standard MRI is relatively insensitive in detecting and monitoring MS disease activity; it misses new lesions that are smaller than 3 ̶ 4 mm in size and does not detect most lesions that occur in the grey matter of the brain (cortex and deep grey matter nuclei, e.g. thalamus and basal ganglia). Therefore, MRI scans also reveal just the tip of the iceberg. This is one of the reasons we also use cerebrospinal fluid (CSF) neurofilament levels as a marker of this microscopic activity.

Disease activity levels

Inactive MS

Many people with MS experience frequent intermittent symptoms or ‘pseudorelapses’ that come on when they are tired, after exercise or have a raised body temperature from a fever, exercise, hot bath or a warm environment. These intermittent symptoms are usually quite stereotyped and last minutes to hours. They are indicative of a previously damaged pathway but do not represent a relapse or disease activity.

Active MS

Most neurologists require evidence of disease activity in the last 12 months, with some of us accepting a 24-month or 36-month window if there is no serial or regular MRI support. However, if you have had no relapses or MRI evidence of new lesions in the last 24 months, then your MS is defined as inactive. (This does not mean your MS is necessarily stable; you could have worsening disability as part of the progressive or smouldering phase of the disease.) Inactive MS needs to be monitored in case it reactivates, in which case you could become eligible for treatment.

Schematic showing different levels of MS disease activity.
*Some neurologists accept MRI activity in the last 24 months, 36 months or even longer as a criterion for active MS.

Highly active MS and rapidly evolving severe MS

Active MS has been divided into an additional two categories that have implications for DMT prescribing (depending on where you live).

  • Highly active MS describes MS with unchanged or increased relapse rates, or ongoing severe relapses compared with the previous year, despite treatment with beta-interferon or another so-called first-line therapy. In England, patients in this subgroup are eligible for natalizumab, alemtuzumab, fingolimod and cladribine.
  • Rapidly evolving severe MS (RES) is defined as two disabling relapses and MRI evidence of activity within a 12-month period. In England, patients in this subgroup are eligible for natalizumab, alemtuzumab and cladribine.

Evolution of diagnostic criteria

In the early 2000s, disease activity was defined using clinical criteria only; you needed at least two documented relapses in the last 2 years to be eligible for DMT.1 This meant that a neurologist had to examine you to confirm abnormalities compatible with a relapse. However, many people with MS without rapid access to a neurologist would recover before being assessed, meaning that their relapses often could not be documented. This was very frustrating for someone wanting to start a DMT. If patients had MRI evidence to support recent disease activity, how could we deny them access to a DMT because they were not seen in a timely way to have their relapse documented in the clinical notes?

In 2009, our criteria incorporated MRI into the definition to allow us to treat so-called high-risk patients with CIS (clinically isolated syndromes compatible with demyelination). These criteria required patients with CIS to have nine or more T2 lesions on MRI or at least one gadolinium-enhancing lesion. These MRI criteria were based on the McDonald diagnostic criteria at the time.2 These eligibility criteria evolved further in 2014, once alemtuzumab was licensed, to include clinical or MRI activity.

References

  1. McDonald WI, et al. Recommended diagnostic criteria for multiple sclerosis: guidelines from the International Panel on the diagnosis of multiple sclerosis. Ann Neurol 2001;50:121–7.
  2. Polman CH, et al. Diagnostic criteria for multiple sclerosis: 2010 revisions to the McDonald criteria. Ann Neurol 2011;69:292–302.
Brain health and holistic management of MS, Causes and prevention of MS

What prognostic group do I fall into?

Having some idea of how bad your MS is, or not, will allow you to discuss important issues with your neurologist so that you can make an informed decision about your MS treatment.

Key points

  • It is hard to predict the disease course of MS accurately for an individual.
  • Population data allow us to define three broad prognostic MS categories: good, indeterminate or poor.
  • Given sufficient time, most people with MS will do badly without treatment.
  • Factors linked to poor prognosis in untreated people with MS are listed.
  • The wide use of disease-modifying therapies is changing the natural history of MS for the better.
  • Adopting a healthy lifestyle, in parallel with appropriate treatment, can help to improve outcomes.  

Predicting MS outcomes: an imperfect science

We can’t predict the prognosis of an individual person with MS very accurately. So don’t let your neurologist mislead you if he or she says you are likely to have benign MS. ‘Benign MS’ is a relative term and can only be used retrospectively once you have had MS for many years or decades. In the era before disease-modifying treatments (DMTs), most people with MS would eventually become disabled, which is why I prefer not to use the term benign MS to predict outcomes. I now use it as a treatment aim, because we want all people with MS to have benign disease.

Three broad prognostic categories

Applying population data to place an individual into a broad prognostic group is often helpful. It allows you to frame your disease in terms of potential outcomes and may help you balance the risks of some treatments against the potential impact of MS later in your life. Predicting outcomes in MS is comparable to an actuary working in the insurance industry; we try to give you an average prognosis with a wide range of possibilities or errors. For this reason, I try to keep it simple and classify people with MS into three prognostic categories: poor, indeterminate, or good. Poor in this context means that if you leave MS to its own devices and let it run its natural course, the average person in this category will do badly.

Most people with a predicted poor prognosis will do badly without treatment for their MS.

Given sufficient time, most people with MS will do badly without treatment. This is why I actively promote treatment based on the scientific rationale that preventing damage now will protect your brain reserve and cognitive reserve and improve your long-term outcome. This is the philosophy behind the MS Brain Health initiative and the report Brain health: time matters in multiple sclerosis,1 which everyone with MS should take time to read. 

Below is a list of factors that have been linked to poor prognosis in people who have not received a DMT. If you have fewer than five of these factors, you are likely to have a good outcome. In comparison, people with ten or more of these factors fall into the poor prognostic group. Most people with MS fall into the intermediate (indeterminate) prognostic group, with 5–10 of these factors. Some of these baseline factors are modifiable,2,3 so you can make the effort to help improve your own prognosis. 

Factors linked to poor prognosis

Please note that the factors listed here only apply to people with MS who are untreated.  It is clear that DMTs are changing the outcome of MS.

  1. Older age of onset (greater than 40 years).
  2. Male sex.
  3. Multifocal onset – more than one site in the nervous system involved with the initial attack.
  4. Efferent or effector system is affected early – that is, the motor (power), cerebellar (balance and coordination) or bladder and bowel functions.  
  5. Partial or no recovery from initial relapses – do you have residual deficits from your initial attacks?
  6. A high relapse rate in the first 2 years – that is, more than two relapses. 
  7. Early disability – an Expanded Disability Status Scale (EDSS) score > 3.0 within 5 years of symptom onset indicates a poor prognosis. You can calculate your EDSS using an online calculator (web-EDSS calculator).
  8. Abnormal magnetic resonance imaging (MRI) scan with large lesion load – more than nine T2 lesions (white blobs) on the baseline MRI.
  9. Active or enhancing lesions on your baseline (initial) MRI – enhancing lesions imply that the lesions are new and actively inflamed.
  10. Posterior fossa lesions on the MRI – these refer to lesions in the back of the brain that involve the brainstem and cerebellum.
  11. Lesions in the spinal cord on MRI.
  12. Obvious early brain atrophy on MRI – brain atrophy refers to premature shrinkage of the brain over and above what you would expect for your age. This information is unlikely to be available to you because neuroradiologists often do not measure or comment on it. 
  13. Retinal thinning on optic coherence tomography (OCT) – people with MS who have lost a lot of retinal nerve fibres do worse than people with a normal retina. Yes, the eye is truly a window into what is happening in the brain of someone with MS. 
  14. Abnormal cerebrospinal fluid – positive immunoglobulin (Ig) bands (known as oligoclonal bands, OCBs) in the spinal fluid.
  15. Raised neurofilament levels in your spinal fluid – this test may not be part of routine care at your neurology centre. Neurofilaments are proteins that are released from damaged nerve fibres, and high neurofilament levels indicate greater damage and poorer outcome than low levels.
  16. Low vitamin D levels – this is controversial, but several studies have shown that people with MS with low vitamin D levels do worse than those with higher levels. These observations do not necessarily imply that by taking vitamin D you will do better. The observation may be related to reverse causation, in that the MS-associated inflammation uses up vitamin D; more inflammation indicates worse MS and is therefore linked with greater depletion of vitamin D levels.
  17. Smoking – smokers with MS do worse than non-smokers. This is modifiable and it is one of many reasons why you should try and give up smoking. 
  18. Comorbidities – people with MS who are obese, have diabetes, prediabetes, hypertension or raised cholesterol do worse than people with MS without these comorbidities.4
  19. Cognitive impairment – people with MS with poor cognitive function do worse than people with MS with good cognition. You can’t really assess your own cognition at present; you need to have it tested by a neuropsychologist.

‘It won’t happen to me’

Humans have interesting psychology in that they tend to consider themselves to be the exception to the rule. Gamblers don’t enter a casino to lose; they always believe they will win. A person with lung cancer who starts chemotherapy believes they will be one of the 10% who is cured. When someone is diagnosed with MS, they believe they will be one of the 30% with benign disease. (The current dogma is that 30% of untreated people with MS will have benign disease.) 

This definition of ‘benign MS’ is based on having no or little disability at 15 years since onset, i.e., an EDSS score of 3.0 or less (no visible disability). However, when you interrogate people with so-called benign MS you find that more than 50% of them have hidden symptoms of depression, anxiety or cognitive impairment. Can we really justify this definition of benign MS? What is more, when you follow people with benign MS past 15 years, only 15% remain benign at 25 years and 5% at 30 years. If you get to 40 years of follow-up, half of these with benign MS will become disabled over the next 10 years.

Moving towards a more favourable outcome

Many will state that these figures are now out of date and there are newer and better figures, which show MS is a more benign disease. You are right, and there are several very good reasons for this. In population-based studies, the proportion of subjects with benign MS is greater than in hospital- or clinic-based studies; for example, in the Olmsted Mayo Clinic MS population, about 45% have benign disease at 15 years. The reason for this is that people with MS with benign disease often drop out of hospital follow-up, but still show up in population-based studies. 

The earlier diagnosis of MS, that is, identification of those who would not have been diagnosed in the past, is changing the definition of MS. For example, most people with a clinically isolated syndrome (CIS) are now being diagnosed as having MS. The wide use of DMTs is beginning to change the natural history of MS for the better; making sure that people with MS adopt a healthy lifestyle is another strategy that can be done in parallel. 

With currently available high-efficacy DMTs and the prospect of effective combination treatments in the future, the proportion of people with MS who experience normal ageing is set to increase. The blue areas illustrate the likely number of people with MS in each prognostic category.
With currently available high-efficacy DMTs and the prospect of effective combination treatments in the future, the proportion of people with MS who experience normal ageing is set to increase. The blue areas illustrate the likely number of people with MS in each prognostic category.
With currently available high-efficacy DMTs and the prospect of effective combination treatments in the future, the proportion of people with MS who experience normal ageing is set to increase. The blue areas illustrate the likely number of people with MS in each prognostic category.
With currently available high-efficacy DMTs and the prospect of effective combination treatments in the future, the proportion of people with MS who experience normal ageing is set to increase. The blue areas illustrate the likely number of people with MS in each prognostic category.

With currently available high-efficacy DMTs and the prospect of effective combination treatments in the future, the proportion of people with MS who experience normal ageing is set to increase. The blue areas illustrate the likely number of people with MS in each prognostic category.

The above figures illustrate what we aim to do with DMTs. We are simply trying to move you to the right, into a more favourable prognostic group. In other words, we want to make sure your MS is benign and that you reach old age with as healthy a brain as possible. Your brain reserve and cognitive reserve protect you from developing age-related cognitive impairment and dementia. MS reduces both of these reserves, which is why it is so important to protect them. 

References

  1. Giovannoni G, et al. Brain health: time matters in multiple sclerosis. 2015, Oxford Health Policy Forum CIC.
  2. Miller DH, et al. Clinically isolated syndromes. Lancet Neurol 2012: 11:157–69.
  3. Weld-Blundell IV, et al. Lifestyle and complementary therapies in multiple sclerosis guidelines: Systematic review. Acta Neurol Scand 2022;145:379–92.
  4. Kappus N, et al. Cardiovascular risk factors are associated with increased lesion burden and brain atrophy in multiple sclerosis. J Neurol Neurosurg Psychiatry 2016;87:181–7.
Stages of MS

What type of MS do I have?

MS has historically been classified into different subtypes, and this subdivision dictates what treatments you are eligible for. These MS disease subtypes are not supported biologically, however, and many MS neurologists are of the opinion that MS is one disease.1

Key points

  • The difference between relapsing MS and non-relapsing progressive MS is explained.
  • The stages of MS have different labels, for historical development and reimbursement reasons, but biologically MS is one disease.
  • From a treatment perspective, the key thing is to know if your MS is active or inactive.
  • Active MS can be differentiated by relapses, MRI evidence of disease activity and raised neurofilament levels in the cerebrospinal fluid.

Type of MS

You should be able to classify yourself as having either relapsing MS or non-relapsing progressive MS. Knowing what type of MS has been diagnosed and whether your MS is active or inactive will allow you to ask your MS neurologist questions about the MS treatments available to you. 

Around 85–90% of people with MS start with so-called relapse-onset MS, i.e. they have a definite attack that is usually followed by a period of complete or incomplete recovery. A single attack may be labelled as a clinically isolated syndrome (CIS): it does not fulfil the current diagnostic criteria for full-blown MS, but it means someone is at risk of further attacks and hence of developing MS in the future.

EDSS, Expanded Disability Status Scale

Once you have more attacks, either clinically in the form of relapse or subclinically with new lesions on magnetic resonance imaging (MRI), then you are usually diagnosed as having MS. The diagram below illustrates the typical course of repeated relapses and remissions, with worsening disability over time, that characterises so-called relapsing–remitting MS (RRMS).

After a variable period, people with relapse-onset MS may notice worsening neurological function without improvement. This is called secondary progressive MS (SPMS) and it can occur with superimposed relapses (so-called relapsing SPMS [RSPMS]) or without relapses.

EDSS, Expanded Disability Status Scale

A small number of people with MS (10–15%) will present with worsening neurological function without a prior history of relapses; this is called primary progressive MS (PPMS).

Interestingly, some people with PPMS go on to have relapses, and this is referred to as progressive relapsing MS (PRMS).

EDSS, Expanded Disability Status Scale

Rarely, someone may present with worsening neurological function, similar to PPMS, but have a prior history of just one relapse. This is referred to as single-attack progressive MS (SAP), but most MS specialists classify these patients as having SPMS. 

In summary …

  • Relapsing MS captures all people with MS who are still having relapses, i.e. within the last 2 years, and includes RRMS, RSPMS and PRMS.
  • Non-relapsing progressive MS refers to SPMS and PPMS: these latter two groups should have no history of recent relapses, i.e. in the last 2 years.

To further confuse things, non-relapsing progressive MS used to be referred to as chronic progressive MS (see below). 

Why is this important?

Different DMTs are licensed for different types of MS, and many treatment guidelines specifically state the type of MS for which a particular drug can be used.

Is MS one or more diseases?

In the past, MS was one disease: either you had MS, or you did not. The stages were referred to as early relapsing MS or chronic progressive MS, but MS was still one disease. 

When disease-modifying therapies (DMTs) were developed, MS was split into multiple sub-types. This categorisation was driven by commercial considerations, and it allowed interferon-beta to be licensed in the US under the Orphan Drug Act. The classification of orphan disease in the US requires there to be fewer than 200,000 people with that diagnosis. Dividing MS into RRMS, SPMS, PPMS and later CIS ensured that each category met this criterion. 

Since then, PRMS and radiologically isolated syndrome (RIS) have been added as potential subtypes. These classifications tend to be arbitrary and overlap, but there is no biological basis to support MS being more than one disease. 

Is your MS active or inactive?

From a treatment perspective, it is important to know if your disease is active or inactive. In active MS, there is evidence of ongoing inflammation in the brain and spinal cord. If you are having relapses, are developing new lesions on MRI or have raised neurofilament (NFL) levels in your cerebrospinal fluid (CSF) or blood, your MS is active. 

Active MS responds to anti-inflammatory treatments; inactive MS is less responsive to currently licensed DMTs. 

Criteria for ‘active’ MS accepted by many MS health professionals. CSF, cerebrospinal fluid; NFL, neurofilament light.
*Some neurologists accept 24 months, 36 months or even longer when assessing MRI activity. There is no international consensus on the gap between the baseline and new MRI scan to define active disease.


The term progressive MS refers to the stage of MS when your disability gets worse – independent of relapses, and possibly of focal inflammatory lesions. I say ‘possibly’, because our current MRI scans don’t show new or enlarging microscopic lesions but only those that are larger than ~3–4 mm. NFL measurements in either the CSF or blood have the advantage of being additive and integrating inflammatory activity. In my experience, about one in ten patients classified as ‘inactive’ based on clinical and MRI activity is found to have active MS when CSF NFL levels are analysed. Unfortunately, however, many MS neurologists, regulators and payers do not accept this latest definition of MS disease activity because tests for NFL levels are currently not widely available. 

In conclusion, knowing the type of MS you have and whether your disease is active or inactive will allow you to discuss with your MS specialist the kinds of treatment available to you. 

References

Giovannoni G, et al. Smouldering multiple sclerosis: the ‘real MS’. Ther Adv Neurol Disord 2022;15:17562864211066751.