Tag Archives: spinal

Male sexual dysfunction in multiple sclerosis

Sexual dysfunction is a common symptom in men with MS, with a prevalence that surpasses that seen in the general population and other chronic disease states. Despite sexual dysfunction being one of the most frequently overlooked and under-addressed MS symptoms, it seldom gets documented and treated in men with MS.

Key points

  • Many men with MS experience some form of sexual difficulty; however, this important aspect of overall well-being is underdiagnosed and undertreated.
  • Such difficulties usually result from a combination of neurological, psychological, social and cognitive factors.
  • Primary dysfunction, caused by damage to the network of signals between the brain, spinal cord and peripheral nerves, can affect the ability to achieve an erection, orgasm or ejaculation; it may also adversely affect libido, sexual desire and genital sensation.
  • Secondary dysfunction results from other MS-related symptoms, including fatigue, spasticity, pain, weakness, bladder dysfunction and bowel dysfunction. Many of the medications used to manage such symptoms may cause or worsen sexual difficulties.
  • Tertiary dysfunction refers to the psychological, emotional and interpersonal challenges of living with MS: depression, anxiety, low self-esteem and impaired body image are among the factors that impact sexual desire and confidence.
  • Management of male sexual dysfunction requires a coordinated, multidisciplinary and personalised approach that involves the MS team, a urologist, physiotherapist, occupational therapist and a psychologist or sex therapist.
  • A wide range of medications, interventions and lifestyle modifications are available that can help couples affected by MS to adapt to the current reality and build a new, satisfying form of intimacy.

An overlooked and distressing symptom

Sexual dysfunction is a common symptom in men with MS, with a prevalence that surpasses that seen in the general population and other chronic disease states. Most studies report that 50–90% of men living with MS will experience some form of sexual difficulty during their disease course. Despite this, sexual dysfunction is one of the most frequently overlooked and under-addressed MS symptoms, and it seldom gets documented and treated in men with MS. This is a clinical paradox, an example of a ‘conspiracy of silence’ where both parties in the clinical encounter overlook a significant issue affecting quality of life.

The main reasons why sexual dysfunction in men with MS is under-recognised, underdiagnosed and undertreated are the taboos of discussing it in the clinic, both from the patient and the HCP perspective. Surveys reveal that the primary barriers to discussing sexual health on the part of HCPs include:

  • time constraints during appointments
  • the major problem that the issue is ‘outside of my role’
  • lack of professional training
  • perceived patient discomfort.

Concurrently, patients are often reluctant to initiate these conversations owing to embarrassment, shame or a deeply held belief that sexuality is somehow incompatible with having a disability. This disconnect between the reality of the patient experience and the focus of the clinical consultation means that a treatable condition that causes significant distress is often left to fester, impacting mental health and relationships. 

Far from being a peripheral concern, sexual function and sexual health are essential components of overall well-being. In men with MS, the onset of sexual dysfunction often precipitates a decline in quality of life, negatively affecting mood, self-esteem and intimate relationships. The distress frequently extends beyond the individual, impacting partners and contributing to marital conflict. The enquiry below illustrates the distress experienced by one man who contacted me for advice; his experience is not uncommon, unfortunately.

Case example

I am a 30-year-old man with relapsing MS. I was diagnosed during my first year of University, aged 18. I presented with transverse myelitis, weakness of both legs and urinary retention. I have been on natalizumab for 12 years and have done very well. However, I have sexual problems with difficulty getting and maintaining an erection. This is affecting my relationship with my wife. Whenever I bring this up with my MS nurse or neurologist, I get dismissed. My GP has given me Viagra, which helps, but its effects are unpredictable, and it often lets me down. I have gotten to the point where I now avoid sexual activity. What advice can you give to help me and others like me?

A complex range of causes

The underlying causes (aetiology) of sexual dysfunction in men with MS are usually complex, variable and dynamic. Some men with MS experience sexual dysfunction as part of a relapse, and they recover with time. However, sexual dysfunction in men with MS usually results from a combination of neurological, psychological, social and cognitive factors. It is therefore vital to approach it from three different perspectives.

  1. Primary dysfunction arises directly from MS lesions within the central nervous system that disrupt the neural pathways governing sexual response.
  2. Secondary dysfunction is the consequence of other MS symptoms, such as fatigue, pain, spasticity, or bladder and bowel issues, which create physical barriers to sexual activity.
  3. Tertiary dysfunction encompasses the psychosocial, emotional and cultural issues that stem from living with a chronic illness, including depression, altered body image and changes in relationships.

Clinical presentations of male sexual dysfunction

Erectile dysfunction

This is the most commonly and widely studied sexual problem in men with MS. Defined as the consistent inability to achieve or maintain a penile erection sufficient for satisfactory sexual performance, erectile dysfunction (ED) affects a large majority of men with MS who report sexual issues, with some estimates as high as 80%. Across the entire male MS population, approximately 70% experience erectile problems at some point after an MS diagnosis.

Ejaculatory and orgasmic dysfunction

While ED receives the most attention, disorders of ejaculation and orgasm are also common and can be even more distressing for patients owing to a lack of effective treatments. Studies estimate that 35–50% of men with MS experience problems with ejaculation. The Male Sexual Health Questionnaire is used as a screen for dysejaculation. Ejaculatory disorders manifest as:

  • delayed ejaculation or anejaculation: difficulty or complete inability, respectively, to ejaculate despite adequate stimulation
  • premature ejaculation: climaxing too rapidly for sexual satisfaction
  • anorgasmia: the failure to reach orgasm
  • altered orgasmic sensation: a less intense or less pleasurable orgasmic experience.

Disorders of libido or sexual desire

A diminished or absent interest in sex is another crucial component of sexual dysfunction in men with MS. Though less rigorously studied than ED, one report suggests that reduced libido affects approximately 40% of men with MS. Loss of libido is particularly complex, often arising from a combination of damage to the brain’s centres that impact desire, the secondary effect of fatigue, and tertiary psychological factors like depression and anxiety.

Altered genital sensation

The direct neurological impact of MS can manifest as abnormal sensations in the genital area, including numbness (decreased sensation), paraesthesias (e.g. pins and needles) or dysaesthesias (unpleasant or painful sensations, such as burning). These sensory disturbances can fundamentally alter the experience of sexual touch, making it less pleasurable or even painful, thereby directly interfering with arousal and orgasm.

The focus on ED in both MS research and clinical practice is driven in part by the availability of effective pharmacological treatments for this issue; this creates an incomplete picture of the patient’s experience. A management plan that successfully restores erectile function, for example, but fails to address a co-existing inability to ejaculate or a profound lack of sexual desire will ultimately fail to improve the patient’s overall sexual satisfaction and quality of life. A thorough clinical evaluation that assesses all phases of the sexual response cycle is therefore needed.

Functional changes underlying male sexual dysfunction in MS

Primary dysfunction

Normal human sexual function is a complex process that requires the integration of signals between the brain, spinal cord and peripheral nerves. MS damages this network in several ways, causing primary sexual dysfunction.

Cerebral and brainstem lesions

MS lesions in the brain and brainstem affect libido, arousal and orgasm.

  • Libido and arousal: Sexual desire is not merely a hormonal process; it originates in the brain. Lesions in higher cortical areas, particularly the limbic system (the brain’s emotional centre) and the hypothalamus, can diminish libido and impair the capacity to process sensory or psychological cues as erotic. MRI studies have correlated dysfunction in arousal and erection with lesions in specific brain regions, including the frontal lobe, prefrontal cortex, temporal lobe, insula and hippocampus.
  • Orgasm: Orgasm is also vulnerable to cerebral damage, and orgasmic dysfunction is associated with lesions in the pons (part of the brainstem), left temporal lobe and right occipital areas.

Spinal cord lesions

The spinal cord relays neuronal signals from the brain to the genitals and transmits sensory information back up to the brain. Lesions along the spinal tracts are the leading cause of ED and ejaculatory disorders.

  • Erectile function: Penile erection is a neurovascular phenomenon mediated by two distinct pathways, both of which can be compromised by MS. A psychogenic erection, initiated by erotic thoughts or sensory stimuli processed by the brain, depends on intact nerve signals travelling down the spinal cord to the pelvic organs. A reflexogenic erection, triggered by direct physical touch to the genitals, relies on a reflex arc located in the sacral segments of the spinal cord (S2−S4). MS lesions can disrupt these pathways individually or in combination. Consequently, depending on the specific location of the spinal damage, a man might be able to achieve an erection from direct touch but not from psychological arousal, or vice versa.
  • Ejaculation: Ejaculation is a far more complex reflex than erection, involving the coordinated contraction of multiple pelvic muscles and requiring precise, intact communication between the brain and the entire length of the spinal cord. This complexity makes it exceptionally vulnerable to disruption by MS lesions, which helps explain why ejaculatory problems in MS are so common and difficult to treat.

Autonomic and hormonal factors

The autonomic nervous system, which controls involuntary bodily functions, plays a pivotal role in regulating erection and ejaculation. MS can cause autonomic dysfunction, further contributing to these problems. Additionally, emerging evidence suggests that chronic inflammation associated with MS, as well as hypothalamic lesions, can disrupt the hypothalamic-pituitary-gonadal axis. This can lead to altered levels of sex hormones, such as testosterone, and has even been linked to impaired sperm quality.

Secondary dysfunction

Secondary sexual dysfunction arises from other MS-related symptoms and the side effects of medications used to treat these symptoms.

  • Fatigue: Fatigue is one of the most common and disabling MS-associated symptoms that directly undermines sexual function by reducing the physical energy and motivation required for intimacy. When daily life is already exhausting, sexual activity can feel like an insurmountable task.
  • Spasticity, pain and weakness: Spasticity, chronic pain, and muscle weakness can make movement difficult and some sexual positions uncomfortable or impossible. Painful muscle spasms can be triggered by the movements of sexual activity, leading to a conditioned avoidance of sex.
  • Bladder dysfunction and bowel dysfunction: The fear of urinary or faecal incontinence during sexual activity is a potent psychological deterrent. With more than 50% of people with MS experiencing bladder and bowel issues, this is a widespread concern. The anxiety and embarrassment associated with a potential accident can cause individuals and their partners to avoid physical intimacy altogether.
  • Side effects of medication: Many of the medications prescribed to manage the symptoms of MS can, ironically, cause or exacerbate sexual dysfunction. Antidepressants, particularly selective serotonin reuptake inhibitors (SSRIs) and tricyclic antidepressants, are well known for causing decreased libido, ED and anorgasmia. Similarly, medications for spasticity, neuropathic pain and urinary frequency can also interfere with sexual responses.

Tertiary dysfunction

Tertiary dysfunction refers to the complex web of psychological, emotional and interpersonal challenges that arise from living with a chronic, unpredictable illness like MS. These factors can be just as debilitating to a person’s sexual health as any physical symptom.

  • Depression and anxiety: There is a strong, two-way, destructive relationship between MS, depression and sexual dysfunction. Depression affects 30–50% of individuals with MS, and it is an independent predictor of sexual dysfunction. The experience of sexual failure can, in turn, trigger or worsen feelings of depression, despair and isolation, creating a vicious cycle that is difficult to break.
  • Body image and self-esteem: The physical changes brought on by MS – such as a limp, the need for a cane or wheelchair, weight gain from steroids or inactivity, or tremors – can profoundly damage a man’s body image and sense of masculinity. This may lead to feelings of being ‘flawed’, ‘broken’ or ‘unattractive’ that erode self-esteem and sexual confidence.
  • Relationship dynamics and role changes: MS does not just affect the individual; it impacts the entire relationship. Performance anxiety and fear of rejection can lead to avoidance of intimacy. A particularly challenging dynamic arises when an intimate partner must assume significant caregiving responsibilities. This ‘role reversal’ can blur the lines between lover and caregiver, disrupting the emotional foundation of the sexual relationship. The partner’s own sexual satisfaction and quality of life are also frequently diminished, highlighting the two-way nature of sexual dysfunction.

Management of male sexual dysfunction in MS

A single treatment approach towards sexual dysfunction in MS often fails because it is a multifactorial problem that requires a coordinated, multidisciplinary approach. This includes the MS team, a urologist, a physiotherapist, an occupational therapist and a psychologist or sex therapist. Failure to implement an interdisciplinary approach is usually because the MS team is reluctant to initiate the conversation about sexual health or lacks knowledge.

Before any medication or therapy is initiated, it is essential to break the ‘conspiracy of silence’ and create a safe, confidential environment for open communication between the patient, their partner and the healthcare provider. For the MS HCP, this involves routinely and proactively asking about sexual health as part of a holistic review of systems, often alongside questions about bladder and bowel function. For the patient, having ‘permission’ to discuss these sensitive issues can be profoundly therapeutic, reducing shame and ‘validating’ their experience as a legitimate medical concern.

Management of primary sexual dysfunction

Pharmacotherapy for erectile dysfunction

  • Oral phosphodiesterase-5 (PDE-5) inhibitors: Medications such as sildenafil (Viagra), tadalafil (Cialis), vardenafil (Levitra) and avanafil (Spedra) are the first-line pharmacological treatments for ED in men with MS. Vardenafil is generally not available on the NHS, and avanafil is prescribed via specialist sexual dysfunction clinics. Sildenafil (Viagra) has a short half-life and needs to be taken before intercourse is planned. In comparison, tadalafil (Cialis) has a long half-life and is called the weekend Viagra. Some men with MS find that combining the two drugs is synergistic. Please note that they come in different doses, so you will need to titrate the dose to find the one that works best for you. These drugs do not create an erection spontaneously; they work by enhancing the natural erectile process, increasing penile blood flow in response to sexual arousal. Clinical trials have demonstrated their efficacy, but they may be effective in only about 50% of men with MS (a lower rate than in the general population), likely due to the underlying neurological deficits. These drugs are contraindicated in men taking nitrate medications for heart conditions.
  • Injectable and intraurethral medications: For men who do not respond to or cannot take oral PDE-5 inhibitors, these locally administered medications are highly effective second-line options. Alprostadil, a synthetic prostaglandin, can be injected directly into the erectile tissue of the penis (intracavernosal injection) or inserted as a small suppository into the urethra. These methods induce an erection directly and are often successful when oral agents are not.

Management of ejaculatory and orgasmic disorders

This remains an area of unmet clinical need, as there are currently no medications specifically approved or consistently effective for treating delayed ejaculation or failure to reach orgasm (anorgasmia) in MS. Some antidepressants (e.g. SSRIs) may be used ‘off-label’ to treat premature ejaculation thanks to their side effect of delaying orgasm. For delayed ejaculation or anorgasmia, the focus shifts to enhancing stimulation through manual or oral techniques or with the use of assistive devices like penile vibrators.

Addressing low libido and sensory changes

A review of the patient’s current medications is needed because many drugs, especially SSRIs, can suppress libido. Switching to an alternative antidepressant with a more favourable sexual side effect profile, such as bupropion or certain SNRIs (serotonin and norepinephrine reuptake inhibitors), may be beneficial. If blood tests reveal low testosterone levels, hormone replacement therapy may be considered to improve desire and energy. For altered genital sensation, the goal is to compensate for the diminished nerve signals by increasing the intensity and focus of stimulation using vibrators, different types of touch, or other sexual aids.

Management of secondary sexual dysfunction

  • Fatigue: Energy conservation is paramount. This involves planning sexual activity for times of day when energy is highest (often the morning), taking a nap beforehand, and collaborating with a partner to find less physically demanding sexual positions, such as spooning.
  • Spasticity: Proactive management can prevent painful muscle spasms from disrupting intimacy. This may include gentle stretching or massage before sex, taking an antispasticity medication like baclofen approximately 30–60 minutes before sexual activity, and/or experimenting with positions that minimise muscle tightness and discomfort.
  • Bladder and bowel issues: Careful planning can alleviate the anxiety surrounding potential incontinence. Strategies include restricting fluid intake for a few hours before sex, ensuring the bladder and bowel are emptied immediately beforehand and using intermittent self-catheterisation if needed. Using a condom can also provide a sense of security against urinary leakage.
  • Cognitive changes: For individuals whose concentration is affected by MS, creating an environment conducive to focusing is helpful. This means minimising external distractions, such as television or phones, and maximising sensual stimuli, including lighting, music and scent, to help maintain focus on the intimate experience.

Psychological counselling and sex therapy are the cornerstone of a holistic management plan and include cognitive behavioural therapy (CBT). CBT can be effective for challenging and reframing the unhelpful thoughts and beliefs that fuel performance anxiety and negative body image. Couples counselling provides a structured forum to improve communication, openly discuss fears and frustrations, and collaboratively explore the changes MS has brought to the relationship, including the sensitive shift from partner to caregiver.

Sensate focus and body mapping are specific sex therapy techniques that are particularly valuable for couples affected by MS. These exercises involve non-demand, non-goal-oriented sensual touching, shifting the focus away from intercourse and orgasm and toward the rediscovery of pleasure. This is especially important when genital sensation has been altered, as it helps couples identify new erogenous zones and broaden their definition of intimacy.

Rehabilitation and lifestyle interventions

These approaches focus on improving physical function and overall health to support sexual well-being.

Pelvic floor exercises are crucial for maintaining erectile rigidity and for the muscular contractions associated with ejaculation. A specialised physiotherapist can design an exercise programme (for example, Kegel exercises) to strengthen these muscles, potentially improving erectile and ejaculatory control. While much of the research into pelvic floor training has focused on women, the principles are also directly applicable to men.

General health has a direct impact on sexual function. Lifestyle modifications such as adopting a heart and brain-healthy diet, engaging in regular physical activity as tolerated, maintaining a healthy weight and quitting smoking can all improve vascular health.

Assistive devices for erectile dysfunction

For men with ED that is refractory to medication, mechanical aids are an important and effective option. Vacuum constriction devices consist of a plastic cylinder placed over the penis, a hand-held pump that creates a vacuum to draw blood into the penis, and a constriction band that is slipped onto the base of the penis to trap the blood and maintain the erection for up to 30 minutes.

Vacuum constriction device operated by a hand-held pump.

Penile prostheses or penile implants are a surgical solution for severe, intractable ED. A device is surgically implanted into the penis that allows the man to create a rigid erection mechanically. This uses saline to inflate the cylinder that is implanted in the penis. The saline can be pumped from a reservoir into the prosthesis or erectile cylinder to mimic an erection. The saline can then be pumped from the cylinder back into the reservoir to cause detumescence. This is typically considered a third-line treatment when all other options have failed.

Penile implant for severe erectile dysfunction

Education, education, education ….

Providing clear, accurate information to the patient and their partner about how MS can affect sexual function helps to demystify the problem, correct common misconceptions (e.g. that sexual activity will worsen the disease), and empower the couple to explore solutions collaboratively.

A management plan for male sexual dysfunction needs to be personalised to address specific primary, secondary and tertiary factors. The goal is often not just to restore previous sexual function but to help the man with MS to adapt to a new reality, encouraging him and his partner to build a new, satisfying form of intimacy.

This calls for improved clinical education of MS healthcare professionals, the integration of standardised screening tools into routine care, and a fundamental shift in clinical culture toward a more holistic model of well-being that values sexual health as a core component of MS management.

Preparing to give birth

Some of the concerns that people with MS raise about giving birth are covered here, such as the possible need for assisted delivery, the likelihood of a normal vaginal delivery and the use of pain-relieving measures.

Am I more likely to need an assisted delivery because I have MS?

In people with MS who are not disabled, the answer is no. However, the more disabled you are, the more likely you are to have an assisted delivery or caesarean section. The latter may be due to fatigue and a lower threshold for the obstetric team to intervene in labour if a woman is significantly disabled. Please discuss the type of delivery you would like with your midwife and/or obstetrician.

Will I be able to have a normal vaginal delivery?

Yes, you should be able to have a normal vaginal delivery. The exception is women with MS with significant disabilities (see above), but even then, a normal vaginal delivery is possible. Providing there are no contraindications, you might consider having a trial of labour and if it fails you can have an intervention such as a caesarean section. Please discuss this with your midwife and/or obstetrician who are best placed to advise and to help you plan.

Will I be able to have an epidural during labour?

Yes, you can have an epidural and other standard pain-relieving measures during labour. There have in the past been cases of people with advanced MS not tolerating spinal anaesthesia well, with some reported to have a slow and incomplete recovery of function. The anaesthetist should be aware of this because an epidural occasionally needs to be converted to a spinal anaesthetic if the epidural needle pierces the dura surrounding the nerve roots at the base of the spine.

References

Krysko KM et al. Treatment of women with multiple sclerosis planning pregnancy. Curr Treat Options Neurol 2021;23:11.

Other articles in this series on Pregnancy and childbirth
Planning for pregnancy
Managing MS during pregnancy
Breastfeeding if you are on a DMT
Concerns about parenting

What is multiple sclerosis?

This is the first of a series of basic lessons to help you understand multiple sclerosis (MS).

Key points

  • MS is an autoimmune disease in which the immune system attacks the central nervous system.
  • Its exact cause is unknown; some contributory environmental factors are outlined.
  • Common manifestations of MS include lesions, relapses and intermittent symptoms, which often worsen with fatigue.
  • Early treatment is important to help prevent the damage that occurs with MS.

Multiple sclerosis (MS) is an organ-specific autoimmune disease. Autoimmune simply means that the immune system, whose primary role is to fight infections and cancers, goes awry and attacks itself. Organ-specific means that a disease is limited to one organ. So, in the case of MS, the immune system attacks the central nervous system (CNS), which consists of the brain, spinal cord and optic nerves.

Every organ in the body has its specific autoimmune disease. For example:

  • joints: rheumatoid arthritis
  • skin: psoriasis 
  • insulin-producing cells of the pancreas: type 1 diabetes
  • intestines: inflammatory bowel disease
  • kidneys: autoimmune nephritis (interstitial or glomerulonephritis).

The cause of MS

At present, the exact cause of MS is unproven. MS is a complex disease that occurs due to the environment’s interaction with inherited or genetic factors.1 Some of the main environmental factors are:

  • low vitamin D levels or a lack of sunshine
  • smoking 
  • Epstein–Barr virus (EBV), the virus that causes infectious mononucleosis (glandular fever) 
  • obesity, particularly in adolescence.

What we don’t know is how these genetic and environmental factors interact to cause MS. There are many genetic variants that predispose someone to get MS, but only a minority of people who have these variants will get the disease. Similarly, only a minority of people exposed to environmental risk factors get the disease.

Mechanisms that underlie the common manifestations of MS

Lesions

MS is characterised by inflammatory lesions – areas of damage or scarring (sclerosis) in the CNS – that come and go. The clinical manifestations of MS depend on where these inflammatory lesions occur. If, for example, a lesion involves the optic nerve, it will cause impaired vision; if it involves the brain stem, it causes double vision, vertigo or unsteadiness of gait; a spinal cord lesion leads to loss of feeling, limb weakness or bladder and bowel problems.  

Relapses

A new MS lesion in a site that is eloquent will cause symptoms and neurological signs; if these last for at least a day, they are called an attack or a relapse. If a lesion occurs in a site not associated with overt symptoms, this is often referred to as a subclinical or asymptomatic relapse. Subclinical relapses can be detected using magnetic resonance imaging (MRI). It is said that for every clinical attack there are 10 or more sub-clinical attacks (new MRI lesions).2 

Damage frequently occurs at the site of MS lesions. The inflammation strips the myelin covering the nerve processes and may cut through axons. Axons are the nerve processes that transmit electrical impulses or signals. When the axons are stripped of their myelin sheath, and/or are cut, they can’t transmit electrical signals. This causes loss of function, which manifests with specific symptoms.

Demyelination: loss of the myelin sheath that insulates nerves, leading to disruption of electrical signals. Image courtesy of Timonina/shutterstock.com

Intermittent symptoms

Surviving axons that pass through the lesion are able to recover function, by synthesising and distributing so-called ion channels across the demyelinated segment or by being remyelinated. Both these processes are not perfect. For example, the new sodium channels may not function normally, so they sometimes fire spontaneously. The spontaneous firing of axons may cause positive symptoms, for example, pins and needles, pain or spasms. The new myelin is typically thinner and shorter than normal and is temperature, fatigue and stretch sensitive. 

Stretch sensitivity

If someone with MS has a lesion in their spinal cord, electric shock-like sensations may occur when they stretch the spinal cord by bending or flexing their neck; this is known as Lhermitte’s sign.  

Temperature sensitivity

Recurrent symptoms may occur when body temperature rises, for example following fever, exercise or a hot bath. The MS symptoms (which may vary among individuals) disappear when the fever resolves or the body cools down. The temperature sensitivity is often referred to as Uhtoff’s phenomenon

Fatigue

Symptoms tend to worsen with physical and/or mental fatigue; for example, someone with MS may begin dragging a leg or dropping their foot after 20–30 minutes of walking. This is because the transmission in the functioning nerves, which have been previously damaged, begins to fail. This failure may be related to a lack of energy and/or to temperature changes that occur with exercise. 

Worsening MS (also called progressive MS)

If the axons, or nerve processes, above and below an MS lesion die off, the surviving axons may sprout to take over the function of the axons below the lesion. This puts an unnecessary strain on the surviving axons, which makes them vulnerable to die off in the future. A reduction in the number of nerves in a neuronal system reduces the neurological reserve of that system, making it more vulnerable to future attacks. In other words, the ability to recover from future attacks is reduced, and the neuronal pathway is susceptible to delayed degeneration and premature ageing. Clearly, if no treatment is given and focal inflammatory lesions continue to come and go, this will cause worsening of the disease. If enough damage is allowed to accrue, even switching off new inflammatory lesions may not prevent the so-called delayed neurodegeneration. This is why one of the primary principles of managing MS is early treatment to prevent damage from occurring in the first place. We have also discovered that the neuronal systems with the longest nerve fibres, in particular the bladder and legs, are much more susceptible to damage. We think this is simply because the longest pathways provide the greatest scope to be hit by multiple MS lesions.

Ageing and MS

As we get older our nervous systems degenerate. If we live long enough, we will all develop age-related neurological problems, such as unsteadiness of gait, loss of memory, reduced vision, loss of hearing, and poor coordination. 

What protects people with MS from becoming disabled and developing age-related neurodegeneration are brain reserve and cognitive reserve. Brain reserve is simply the size of your brain or the number of nerve cells you have. Cognitive reserve, in comparison, relates to how well these nerves function; it is associated with your level of education and how well you enrich your life by using your brain. From about 35 years of age, our brains start to shrink. In MS, this brain shrinkage is in general much greater than normal, and the resulting reduction in brain and cognitive reserve almost certainly primes the nervous system to age earlier. This is one of the reasons why people with MS continue to develop worsening disability later in the course of their disease. This insight is one of the main reasons why we promote early effective treatment of MS to protect and maintain brain and cognitive reserves.  


References

  1. Olsson T, et al. Interactions between genetic, lifestyle and environmental risk factors for multiple sclerosis. Nat Rev Neurol 2017;13:25–36.
  2. Gafson A, et al. The diagnostic criteria for multiple sclerosis: From Charcot to McDonald. Mult Scler Relat Disord 2012;1:9–14

Am I sure that I have MS?

The multiple sclerosis misdiagnosis rate is around 5% and this has major implications for individuals and the treatment of MS.

Key points

  • A wrong diagnosis of MS may have financial, social and psychological consequences for the individuals concerned, affecting major life decisions.
  • Some MS treatments have life-threatening complications and should only be prescribed for people with a clear diagnosis of MS.
  • Some of the diseases that mimic MS can be made worse by disease-modifying treatments for MS.
  • Diagnostic criteria for MS have evolved and now take account of clinical, electrical, laboratory and magnetic resonance imaging findings.

A case study

She had been diagnosed with multiple sclerosis 8 years ago and had been taking interferon-beta since her diagnosis. I told her that I didn’t think she had MS and that her diagnosis was almost certainly complicated migraine with aura. The lesions on her magnetic resonance imaging (MRI) scan were non-specific white matter lesions and not inflammatory. Her neurological examination, spinal fluid analysis and evoked potentials (EPs) were normal. What clinched the non-MS diagnosis for me was the history of neurological events, which were too short-lived and migratory to be MS attacks. The final piece of the jigsaw was that a special MRI sequence showed none of her white matter lesions had a central vein, which told me that none of her white matter lesions was an MS lesion.  Her anger was palpable. She was angry because she had decided not to start a family and had changed her career because of the fear of becoming disabled in the future and not being able to work or look after a child.  This case illustrates why I always try to review the diagnosis of patients referred to me with MS and why it is important to answer this question before starting a disease-modifying therapy (DMT).   

Making a diagnosis of MS

Unfortunately, there is no single test to diagnose MS. Rather, MS is diagnosed by combining a set of clinical and MRI findings, electrical or neurophysiological investigations and laboratory tests. If these tests fulfil a set of so-called MS diagnostic criteria, the healthcare professional (HCP) or neurologist makes a diagnosis of MS. 

The underlying principles of diagnosing MS are to show the dissemination of lesions in space and time and exclude possible mimics of MS. The diagnostic criteria have evolved over time from 1) being based purely on clinical attacks,1 to 2) include electrical and spinal fluid tests as well as clinical attacks,2 and 3) to add on the use of MRI to help confirm dissemination in time and space.3–6  

Dissemination in time 

This means that two attacks or MS lesions must occur at least 30 days apart or that oligoclonal bands (OCBs) of immunoglobulins can be detected in the spinal fluid.

Dissemination in space 

This requires MS lesions to occur in different locations, for example, the optic nerve and the spinal cord. 

Electrical tests

The electrical or neurophysiological tests are called evoked potential (EPs) and test electrical conduction in a particular pathway. They can show lesions in nerve pathways that are not evident on the neurological examination or seen on MRI. The EPs can also show slow electrical conduction, which is one of the hallmarks of diseases that affect myelin, the insulation around nerves that is responsible for speeding up the electrical conduction of nerve impulses.

Laboratory tests

The laboratory tests are typically done to exclude other diseases that can mimic MS. Examining the spinal fluid for the presence of OCBs is useful in helping to make an MS diagnosis. OCBs are the fingerprint of a specific type of immune activation within the central nervous system (CNS). The OCB fingerprint is relatively specific for the diagnosis of MS in the correct clinical context. (OCBs are also found in CNS infections and other autoimmune diseases, but these are relatively easy to differentiate from MS.)

Please be aware that you may have MS according to the latest diagnostic criteria when you could not be diagnosed with MS using past criteria.

Why is a correct diagnosis important?

Neurologists get the diagnosis wrong in approximately 5% of people with MS. In other words, one in 20 people who have a diagnosis of MS in life does not have MS when their brain is studied post mortem. This data is based on a large study in a region of Denmark.7 More recently, a study from a specialist MS centre in the United States reported a misdiagnosis rate of approximately 15% in patients with presumed MS referred to their centre for treatment.8 

Why is getting the diagnosis of MS correct so important? Firstly, some MS treatments have life-threatening complications; you don’t want to expose people without MS to these complications. More concerning is that some of the diseases that mimic MS can be made worse by MS DMTs. Finally, a diagnosis of MS has many psychological, social, financial and economic implications. Even if you turn out to have ‘benign disease’, just having a diagnosis of MS, has implications for your life choices and may impact your ability to get insurance cover, to name obvious examples. I, therefore, advise you to make sure you have MS and not an MS mimic.

Common MS mimics

References

  1. Schumacher GA, et al. Problems of experimental trials of therapy in multiple sclerosis: Report by the Panel on the Evaluation of Experimental Trials of Therapy in Multiple Sclerosis. Ann N Y Acad Sci 1965;122:552–68.
  2. Poser CM, et al. New diagnostic criteria for multiple sclerosis: guidelines for research protocols. Ann Neurol 1983;13:227–31.
  3. 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.
  4. Polman CH, et al. Diagnostic criteria for multiple sclerosis: 2005 revisions to the “McDonald Criteria”. Ann Neurol 2005;58:840–6.
  5. Polman CH, et al. Diagnostic criteria for multiple sclerosis: 2010 revisions to the McDonald criteria. Ann Neurol 2011;69:292–302.
  6. Thompson AJ, et al. Diagnosis of multiple sclerosis: 2017 revisions of the McDonald criteria. Lancet Neurol 2018;17:162–73.
  7. Engell T. A clinico-pathoanatomical study of multiple sclerosis diagnosis. Acta Neurol Scand 1988;78:39–44.
  8. Kaisey M, et al. Incidence of multiple sclerosis misdiagnosis in referrals to two academic centers. Mult Scler Relat Disord 2019;30:51–6.

What are the consequences of not treating MS?

Are there valid reasons not to treat MS with a disease-modifying therapy? What are the consequences of not treating MS? Is watchful waiting justified?

Key points

  • Untreated MS will, given time, result in physical disability, impaired quality of life and ‘hidden’ problems such as cognitive impairment, anxiety and depression.
  • Brain atrophy, or shrinkage, occurs at a faster rate in people with MS than in healthy individuals.
  • Optic neuritis, inflammation or destruction of nerve fibres in the brain and spinal cord, and extensive damage to the cerebral cortex (grey matter) are some consequences of MS lesion development.
  • Quality of life impacts may include reduced mobility, relationship difficulties, increased likelihood of unemployment and memory impairment.
  • Without treatment, the life expectancy of people with MS is reduced by about 6 ̶ 8 years.
  • There are, however, several valid reasons why some people with MS prefer not to receive disease-modifying treatments.

Risks from no disease-modifying treatment

Many patients ask me what will happen to their MS if they don’t take a disease-modifying treatment (DMT) and how effective DMTs are at preventing negative outcomes. Here I try and address questions you need to ask yourself before starting a DMT.

If you are an individual with MS, predicting your disease course is difficult. However, many studies monitoring groups of people with MS show patterns in relation to the progression of the disease and its outcome, with various data sets being consistent.

Given sufficient time, most people with MS who are not treated will become disabled. Most people focus on physical disability, but MS causes many hidden problems, such as cognitive impairment, anxiety and depression.

How untreated MS can progress – headline results

The slides below summarise some of the outcomes of untreated MS; these include brain changes (atrophy), further MS lesion development, reduced health-related quality of life, long-term impact on physical and mental health and shorter life expectancy. (To enlarge an individual slide, click on the arrow at the top right.)

Brain changes
MS lesion development
Quality of life impact
Long-term outlook

DMTs have changed the landscape

It is important to note that these outcomes are from the pre-DMT era and don’t apply to populations of people with MS treated with DMTs. New real-life data indicate that DMTs, particularly high-efficacy DMTs, are preventing many of these problems. By not being on a DMT, if you have active MS, you are at risk of acquiring damage from focal inflammatory lesions. Early in the disease course, you may not be aware of this damage because of the remarkable capacity of the nervous system to compensate for damage (neurological reserve). However, once the compensatory mechanisms have been exhausted, further damage results in overt disability. It is important to regard DMTs as preventive treatments, i.e. their aim is to delay, and hopefully prevent, future disability.

Possible reasons for not receiving a DMT

Many people with MS will not be on a DMT, for a variety of reasons. The list below is probably not extensive; if you know of other reasons why someone who qualifies is not taking a DMT, please let me know.

Inactive MS

Someone with inactive MS will not be eligible for a DMT. There is no standard definition of active MS. To me, active MS is recent evidence of focal inflammatory disease activity, defined as:

  • clinical relapse(s) in the last 2 years
  • OR magnetic resonance imaging (MRI) activity in the last 12 ̶ 36 months (new or enlarging T2 lesions or T1 Gd-enhancing lesions)
  • OR a raised cerebrospinal fluid (CSF) neurofilament light chain level in the last 12 months.

Worsening disability in MS without focal inflammatory disease activity is not active disease. It can be due to damage caused by past inflammation, smouldering MS or the effects of premature ageing; anti-inflammatory DMTs can’t address this problem. We need different types of DMTs to address these mechanisms – for example, neuroprotective and/or remyelination therapies and anti-ageing therapies.

Watchful waiting

In many situations, some neurologists think someone with MS will end up having benign disease, so they are not prepared to start treatment until the patient develops some overt disability. I abhor this practice and it is one of the reasons I spend so much of my time disseminating knowledge and getting involved with health politics. Watchful waiting, in terms of treating MS, is not supported by data. The earlier and more effectively you treat MS, the better the outcome. The only situation I could condone watchful waiting in someone with active MS is when the diagnosis of MS is in question. Sometimes in neurology, time is the best diagnostician. If the person has MS, it will declare itself with further disease activity, and this would be the trigger to start a DMT.

Family planning

Trying to fall pregnant, pregnancy or breastfeeding are common reasons to interrupt or stop DMTs. Please note that most neurologists now have options to treat MS during pregnancy and while breastfeeding, so this is becoming a less common reason for not taking a DMT.

Risk aversion

Some people with MS are not prepared to take the potential risks associated with DMTs.

Personal reasons

Some people with MS don’t believe in having their MS treated, preferring to try alternative medicines and turn down traditional DMTs. If you are one of these people, I would recommend you continue to interact with your MS team and have regular monitoring of your MS (clinical, MRI, patient-related outcome measures [PROMS] and possibly CSF analyses). Then, if these alternative strategies don’t work, you will keep open the option of treatment with a ‘traditional DMT‘. Most alternative treatment strategies for MS are compatible with DMTs and hence should be viewed as complementary. Understanding the difference between complementary and alternative treatments is important. Complementary treatment strategies are part of the holistic management of MS.

Financial constraints

In some parts of the world, MS treatment is not covered by a national health service or medical insurance scheme and some people with MS simply can’t afford DMTs. Even in rich countries, people with MS who are disenfranchised don’t have access to treatment; these may include illegal immigrants, refugees and asylum seekers waiting for their applications to be processed.

Progressive or more advanced MS

In most countries, neurologists don’t initiate treatment in patients with more advanced MS. This approach is based on a lack of evidence of the effectiveness of DMTs in this population. However, we are increasingly offering ocrelizumab (for active primary progressive MS), siponimod (for active secondary progressive MS) or off-label therapies on a compassionate basis to people with more advanced MS. In addition, there is also the potential to participate in clinical trials of new treatments for more advanced MS.

Ageism

Some healthcare systems and some neurologists are reluctant to start DMTs in people with MS who are over a certain age. This is based on a lack of evidence of the effectiveness of DMTs in this population, and it is why we need to do clinical trials in older people with MS.

Comorbidities

Many people have other medical problems for which the treatment takes priority over the treatment of MS. For example, a patient of mine was diagnosed with stage four bowel cancer. After her surgery, she started an intensive period of chemotherapy during which we stopped her DMT.

References

  1. Fisher E, et al. Gray matter atrophy in multiple sclerosis: a longitudinal study. Ann Neurol 2008;64:255–65.
  2. Barkhof F, et al. Imaging outcomes for neuroprotection and repair in multiple sclerosis trials. Nat Rev Neurol 2009;5:256–66.
  3. Simon JH. Brain atrophy in multiple sclerosis: what we know and would like to know. Mult Scler 2006;12:679–87.
  4. Ziemssen T, et al. Optimizing treatment success in multiple sclerosis. J Neurol 2016;263:1053–65.
  5. Hickman SJ, et al. Detection of optic nerve atrophy following a single episode of unilateral optic neuritis by MRI using a fat-saturated short-echo fast FLAIR sequence. Neuroradiology 2001;43:123–8.
  6. Trapp BD, et al. Axonal transection in the lesions of multiple sclerosis. N Engl J Med 1998;338:278–85.
  7. Peterson JW, et al. Transected neurites, apoptotic neurons, and reduced inflammation in cortical multiple sclerosis lesions. Ann Neurol 2001;50:389–400.
  8. Orme M, et al. The effect of disease, functional status, and relapses on the utility of people with multiple sclerosis in the UK. Value Health 2007;10:54–60.
  9. Pfleger CC, et al. Social consequences of multiple sclerosis (1): early pension and temporary unemployment – a historical prospective cohort study. Mult Scler 2010;16:121–6.
  10. Kobelt G, et al. Costs and quality of life of patients with multiple sclerosis in Europe. J Neurol Neurosurg Psychiatry 2006;77:918–26.
  11. Feuillet L, et al. Early cognitive impairment in patients with clinically isolated syndrome suggestive of multiple sclerosis. Mult Scler 2007;13:124–7
  12. Confavreux C and Compston A. Chapter 4. The natural history of multiple sclerosis. In: McAlpine’s Multiple Sclerosis, Fourth Edition, 2006; 183 ̶ 272. Churchill Livingstone.
  13. Weinshenker BG et al. The natural history of multiple sclerosis: a geographically based study. I. Clinical course and disability. Brain 1989;112:133 ̶ 46.
  14. Torkildsen GN, et al. Survival and cause of death in multiple sclerosis: results from a 50-year follow-up in Western Norway. Mult Scler 2008;14:1191–8.
  15. Kingwell E, et al. Relative mortality and survival in multiple sclerosis: findings from British Columbia, Canada. J Neurol Neurosurg Psychiatry 2012;83:61–6.
  16. Sadovnick AD, et al. Cause of death in patients attending multiple sclerosis clinics. Neurology 1991;41:1193–6.
  17. Brenner P, et al. Multiple sclerosis and risk of attempted and completed suicide – a cohort study. Eur J Neurol 2016;23:1329–36

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.

Inactive MS - format updated 180625 SS

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, the criteria for diagnosing MS 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 sclerosisAnn 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.

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 deteriorate 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. 

Factors linked to poor prognosis

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

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) MRIenhancing 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. Low vitamin D levels 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 view among MS neurologists 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 proportion of people with MS in each prognostic category.

The above figures illustrate what we aim to do with currently available high-efficacy DMTs (compared with older, lower efficacy treatments). 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. With the prospect of effective combination treatments in the future, the proportion of people with MS who experience normal ageing is set to increase.

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.

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 from inactive MS 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 of symptoms 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 score
EDSS, Expanded Disability Status Scale score

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 score
EDSS, Expanded Disability Status Scale score

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 score
EDSS, Expanded Disability Status Scale score

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 regarded as 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.