Multiple sclerosis (MS)

What is multiple sclerosis (MS)?#

Multiple sclerosis is a chronic, complex disease in which the immune system mistakenly attacks the body’s own tissue. This is known as an autoimmune response.

In MS, the immune system attacks and damages the fatty material (myelin) that insulates the nerves of the central nervous system: the brain, spinal cord and optic nerves. This process is called demyelination.

Healthy myelin acts like the covering of an electrical cord. It protects your nerve fibres and allows them to transmit impulses (messages) quickly and effectively. Demyelination causes inflammation and scarring (multiple sclerosis means “many scars”). The scars, known as plaques or lesions, affect your nerves’ ability to carry messages between your brain and the rest of your body.

There is not yet a cure for MS, but research into treatment and management continues to make progress.

Why MS affects everyone differently#

Demyelination can occur anywhere in the central nervous system, so each person’s experience of MS is unique and can change at different stages of life.

After demyelination, the brain works to repair the tissue and resolve the inflammation, and can redirect messages to other areas. It is a bit like being diverted onto an alternative route because of roadworks. However, the repair is often incomplete, and some nerve tissue is irreversibly destroyed.

Over time this can lead to a decrease in brain volume, known as brain atrophy. Healthy adults have a small amount of brain atrophy from natural ageing, but in many people with untreated MS it occurs much faster. Current MS treatments aim to prevent new lesions that lead to irreversible damage and brain atrophy. Research is also focused on ways to repair damaged myelin and help prevent symptoms.

How common is MS?#

MS is a common disease. More than 2.8 million people live with MS worldwide. Around three quarters of people with MS are women, and it is a leading cause of disability in young adults. Diagnosis most often occurs between the ages of 20 and 40, although children can also be diagnosed.

Types of MS#

Knowing the type of MS you have can help you understand the likely course of the disease and make informed treatment decisions.

• Relapsing remitting MS (RRMS) – the most common type. It is characterised by clearly defined attacks (active disease activity) followed by periods of complete or partial recovery (remission). During remission the disease does not appear to progress; symptoms may disappear, or some may continue or become permanent. About 85% of people with MS are initially diagnosed with RRMS.
• Secondary progressive MS (SPMS) – diagnosed when an initial relapsing remitting phase is followed by a progressive phase in which the disease continually worsens. Attacks and partial recoveries may still occur. The change from RRMS to SPMS does not follow a set path and can be difficult to pinpoint; for most people it takes many years, and for some many decades.
• Primary progressive MS (PPMS) – diagnosed when the condition follows a progressive course from the beginning, with increasing disability and usually without periods of remission or acute attacks. About 10–15% of people with MS are diagnosed with PPMS.

You may also hear MS described as active or inactive. Active disease refers to new lesions leading to clinical relapses, new findings or progression. Inactive disease means MS is stable with no evidence of current activity.

Symptoms of MS#

Symptoms are varied and unpredictable, depending on which part of the central nervous system is affected and to what degree. No two cases of MS are the same, symptoms may vary from day to day, and they can interact with each other. Some symptoms are visible to others, while many are invisible.

Common symptoms include:

• Motor control – difficulties with walking, balance or coordination, muscle spasms or tremors, muscle weakness, slurred or slowed speech, swallowing difficulties, dizziness or vertigo
• Fatigue – extreme tiredness, often combined with heat sensitivity, which can affect physical, emotional and mental abilities
• Sensory issues – visual disturbances (such as blurred or double vision, changes in depth perception, or partial or complete sight loss), altered sensations such as pins and needles or numbness, neurological pain, and sensitivity to heat or cold
• Bladder and bowel dysfunction – including incontinence, needing to pass urine more or less often, urgency, frequent urination at night, constipation or diarrhoea
• Sexual dysfunction – which can be directly related to MS lesions or result from other symptoms
• Cognitive symptoms – including “brain fog”, impaired memory and concentration, and changes in processing speed
• Mood symptoms – such as personal and emotional changes, anxiety, depression and difficulty sleeping

MS is a chronic disease that requires constant adjustment, management, monitoring and resilience, and it affects those around you in different ways at different times.

What causes MS?#

There is no single cause of MS. Studies point to a complex interaction between genetics, environment and lifestyle factors:

• Genetics – several genes are believed to influence susceptibility to MS, alongside environmental factors.
• Infection – a variety of viruses have been linked to MS, including the Epstein-Barr virus.
• Geographical location – MS is more common in areas further from the equator (the latitudinal gradient). The reasons are still unclear, but there may be a link to exposure, or lack of exposure, to ultraviolet light.
• Vitamin D – many studies show a correlation between vitamin D levels and MS. Low levels may increase the risk of developing MS and may negatively affect outcomes.
• Smoking – significantly increases the chance of developing MS or of the disease progressing.

How is MS diagnosed?#

Diagnosing MS can be difficult, because early symptoms such as fatigue, stumbling, unusual sensations, slowed thinking or eyesight problems can also be caused by other conditions. There is no single test for MS.

If your doctor thinks you may have MS, they will usually refer you to a neurologist with experience in MS and access to specialist tools and a healthcare team. Tests used to diagnose MS include:

• Neurological examination – testing the cranial nerves, reflexes, muscle strength, sensation and vision to detect possible areas of damage. Your walking speed and style may also be assessed.
• Blood tests – mainly to rule out other causes of your symptoms.
• Magnetic resonance imaging (MRI) – to look for scarring (plaques or lesions) in the brain and spinal cord.
• Lumbar puncture – to test the cerebrospinal fluid; this can support MRI findings and help rule out other diseases.
• Neurophysiology tests – such as evoked potentials, which measure electrical activity and follow impulses through the nerves of the eyes, ears or peripheral nerves to detect lesions that may not be seen on MRI.

If lesions are found, a neurologist will look for evidence that the scarring happened at different points in time (“disseminated in time”) and in different parts of the central nervous system (“disseminated in space”). This forms the basis of international diagnostic guidelines known as the McDonald criteria.

To achieve the best outcomes, it is recommended that delays in diagnosis be minimised and that treatment and management goals be set early. Being informed helps you take part in decisions, and a collaborative process between patient and healthcare provider leads to the best results.

What are MS relapses?#

A relapse is a relatively sudden episode of a new symptom, or the worsening of an existing one, that continues for longer than 24 hours, is separated from the previous attack by at least 30 days, and cannot be explained by other causes such as infection or overheating.

Relapse symptoms can evolve over one to seven days and then plateau for several weeks. It can take months for the body to recover. How often relapses occur and how severe they are can be variable and unpredictable.

If you think you are experiencing a relapse, notify your healthcare team or nurse as soon as possible. They can guide you through it and provide supportive treatment if required. Keeping a diary of your symptoms gives your doctor accurate information for treating and managing your MS, and a relapse may indicate that your treatment is no longer suitable.

Because of the on-again, off-again nature of MS, you and your loved ones may experience a range of emotional responses, and support is available during these times.

How is MS treated?#

There are no medications to cure MS; instead, they are used to modify the course of the disease. A number of disease-modifying treatments (DMTs) are available for RRMS, SPMS and PPMS.

For RRMS, treatment aims to:

• minimise relapses
• reduce inflammation
• prevent the formation of new lesions
• minimise brain atrophy
• restore function and reduce the impact of symptoms on daily life

DMTs can be given by injection, orally as a tablet or capsule, or intravenously. Some can have significant side effects, so specialist MS healthcare teams usually manage them and provide safety guidance and monitoring. Studies show that early diagnosis and starting DMTs early can lead to better outcomes.

Your MS healthcare team#

If you are diagnosed with MS, your doctor will work closely with a specialist team. This may include a neurologist, an MS nurse and other allied health practitioners such as an occupational therapist, physiotherapist, psychologist and continence nurse.

Your team will discuss the aims of treatment, which treatments might suit you, and the pros and cons of each option. Shared decision-making, where the team and the patient make decisions together based on the patient’s values, preferences, life experiences and circumstances, is a valuable tool in clinical care. It is a partnership of care.

Where possible, it is recommended that you have regular treatment reviews and an MRI scan at least once a year to check for disease activity.

Brain health and lifestyle#

There are several things you can do to keep your brain as healthy as possible:

• keep your weight under control and follow a healthy diet
• avoid smoking and limit alcohol
• keep your mind and body as active as possible
• learn ways to manage stress, since MS can cause stress because of its unpredictable nature, and stress in turn can increase the risk of a relapse

If you have a sensitivity to heat or cold that worsens your symptoms, talk to your healthcare team about strategies to manage it.

Medications and physical therapies can be complemented by other therapies. Be cautious with complementary therapies and sceptical of “miracle cure” claims. Always check with your healthcare team before starting any complementary treatment, as some may interact with your medications.

Key points#

• Demyelination causes inflammation and scarring (multiple sclerosis means “many scars”).
• Research is focused on finding ways to repair damaged myelin and help prevent MS symptoms.
• MS is common: more than 2.8 million people live with MS worldwide.
• Multiple sclerosis is a leading cause of disability in young adults.
• There are different types of MS, with relapsing remitting MS (RRMS) being the most common.

Where to get help#