Understanding Multiple Sclerosis

What is it?
Multiple sclerosis (MS) (aka encephalomyelitis disseminate) is a potentially disabling disease of the brain and spinal cord (central nervous system). In MS, the immune system attacks the protective sheath (myelin) that covers nerve fibres and causes communication problems between your brain and the rest of the body.

In most cases, MS isn’t a fatal condition, and most people with it have a near-to-normal life expectancy. But since the disease varies so much from person to person, it can be difficult for doctors to predict whether their condition will worsen or improve. NHS^[1] confirms that MS is rarely fatal, but complications may arise from severe MS – such as chest or bladder infections or swallowing difficulties. The average life expectancy for people with MS is around 5 to 10 years lower than average. The good news is that this gap appears to be getting smaller. While better treatments seem to deserve much of the credit for this advance, there’s also plenty that those with the condition can do themselves to ensure they live long and well.

MS attacks tissues in the brain and spinal cord (known as the central nervous system (CNS)). This system includes the complex network of nerve cells responsible for sending, receiving, and interpreting information from all parts of the body. During daily life, the spinal cord sends information to the brain via these nerve cells. The brain then interprets the data and controls how you react to it. You can think of the brain as the central computer and the spinal cord as a cable between the brain and the rest of the body.^[2]

A picture containing dark Description automatically generated
Picture Credit: Main symptoms of Multiple Sclerosis. Attribution: Mikael Häggström, Public domain, via Wikimedia Commons.
File URL: https://upload.wikimedia.org/wikipedia/commons/b/bf/Symptoms_of_multiple_sclerosis.svg

Symptoms^[3]The symptoms experienced by people with MS can be grouped according to how they are affected. Some people develop lesions (nerve damage) without noticing symptoms because the damage happens to be in a part of the brain or spinal cord, which can re-route nerve signals around the damage. Sometimes, symptoms can be caused by nerve damage within the part of the brain that deals with that part of the body.

Alternatively, the nerve damage could have occurred in a nerve carrying information from the brain to the body. Damage at either of these places might result in a similar symptom. For example, a lesion in the spinal cord leading to the leg muscles or a lesion in the cerebellum part of the brain (which manages coordination and balance – the medical term for coordination problems is ataxia – could result in you finding yourself stumbling or falling over. All of these symptoms are treatable and are definitely worth discussing with the MS Nurse or healthcare team for further advice.

The symptoms of MS vary widely from person to person and can affect any part of the body. They include:

Fatigue (exhaustion out of all proportion to the task undertaken).
Mobility problems (indicating problems with balance or coordination in the legs).
Vision problems (such as blurred, altered vision, or pain moving the eyes).
Problems controlling the bladder.
Numbness or tingling in different parts of the body, particularly the skin.
Muscle stiffness and spasms.
Problems with thinking, learning and planning (slowed thinking – resulting in forgetting things, poor concentration, or getting lost)

Depending on the type of MS, symptoms may come and go in phases or get steadily worse over time. There are other symptoms of MS, but the patient is less likely to experience them early on, such as:

Depression and anxiety
Sexual problems
Bowel problems
Speech and swallowing difficulties

Most people with MS only have a few of these symptoms. It’s best to see a GP if you’re worried you might have early signs of MS. The symptoms can be similar to several other conditions, so they’re not necessarily caused by MS. Letting them know about the type and pattern of symptoms you’re experiencing in detail will help them determine whether you might have the condition. If your GP thinks you could have MS, you are likely to be referred to a neurologist (a specialist in conditions of the nervous system) for an assessment.

Genetics^[4]Although MS is not a purely hereditary disease, several genetic variations have been shown to increase the risk. Some of these genes appear to have higher levels of expression in microglial cells than expected by chance.^[5] The probability of developing the disease is higher in relatives of an affected person, with a greater risk among those more closely related.^[6]

An identical twin of an affected individual has a 30% chance of developing MS, 5% for a non-identical twin, 2.5% for a sibling, and an even lower chance for a half-sibling. If both parents are affected, the risk for their children is ten times that of the general population. MS is also more common in some ethnic groups than others.^[7]

Tests for Multiple Sclerosis^[8]Diagnosing MS is complicated because there is no single test that can positively diagnose it. Other possible causes of your symptoms may need to be ruled out first:

It may also not be possible to confirm a diagnosis if you have had only one attack of MS-like symptoms.
A diagnosis can only be made with confidence once there’s evidence of at least two separate attacks, although this may include signs of attacks on an MRI scan that you may not realise you have had.

Neurological test
Your neurologist will look for abnormalities, changes or weakness in your vision, eye movements, hand or leg strength, balance and coordination, speech and reflexes. These may show whether your nerves are damaged in a way that might suggest MS.

MRI scan
An MRI scan is a painless scan that uses strong magnetic fields and radio waves to produce detailed images of the inside of the body. It can show whether there’s any damage or scarring of the myelin sheath (the layer surrounding your nerves) in your brain and spinal cord. Finding this can help confirm a diagnosis in most people with MS.

Evoked potential test
There are several types of evoked potential test. The most common type assesses how well the eyes work. Light patterns are shown to the eyes while your brainwaves are monitored using small, sticky patches called electrodes placed on your head. It’s a painless test and can indicate whether it takes your brain longer than normal to receive messages.

Lumbar puncture
A lumbar puncture is a procedure to remove a sample of your spinal fluid by inserting a needle into the lower back. Spinal fluid surrounds your brain and spinal cord, and changes in the fluid can suggest problems with the nervous system. The procedure is done under local anaesthetic, which means you’ll be awake, but the needle’s area will be numbed. The sample is then tested for immune cells and antibodies, which signifies that your immune system has been fighting a disease in your brain and spinal cord. Lumbar punctures are very safe, but are often uncomfortable and can cause a headache that occasionally lasts for up to a few days. A lumbar puncture will often be performed to provide extra information if your symptoms or scans are unusual.

Blood tests
Blood tests are usually performed to rule out other causes of the patient’s symptoms, such as vitamin deficiencies or a rare but potentially very similar condition called neuromyelitis optica.

Determining the Type of Multiple Sclerosis^[9]Once a diagnosis of MS has been made, the neurologist may be able to identify which type of MS the patient has. It will largely be based on:

The pattern of your symptoms – such as whether you experience periods when your symptoms get worse (relapses) then improve (remissions), or whether they get steadily worse (progress); and
The results of an MRI scan – such as whether there’s evidence that lesions in your nervous system have developed at different times and at different places in the body.

But the type of MS that the patient is suffering from only becomes clear over time because the symptoms of MS are so varied and unpredictable. It can take a few years to diagnose progressive MS accurately because the condition generally worsens slowly.

There are four types^[10] of multiple sclerosis:

Clinically isolated syndrome (CIS): When someone has their first episode of MS symptoms, healthcare providers often categorise it as CIS. Not everyone who has CIS goes on to develop multiple sclerosis.
Relapsing-remitting MS (RRMS): this is the most common form of multiple sclerosis. People with RRMS have flare-ups – also called relapse or exacerbation – of new or worsening symptoms. Periods of remission follow (when symptoms stabilise or go away).
Primary progressive MS (PPMS): People diagnosed with PPMS have symptoms that slowly and inexorably worsen without any periods of relapse or remission.
Secondary progressive MS (SPMS): In many cases, people originally diagnosed with RRMS eventually progress to SPMS. With secondary-progressive multiple sclerosis, you continue to accumulate nerve damage. Your symptoms progressively worsen. While you may still experience some relapses or flares (when symptoms increase), you no longer have periods of remission afterwards (when symptoms stabilise or go away).

Treatment^[11]Multiple sclerosis (MS) causes damage to nerve fibres in the central nervous system. Over time, it can lead to vision problems, muscle weakness, loss of balance or numbness. Several drug therapies can limit nerve damage and slow the disease’s progression.^[12]

Although there’s currently no cure for multiple sclerosis, medicines and other treatments can help control the condition and ease some symptoms. Treatment for MS depends on the stage of the disease and the specific symptoms the person has. Treatment may include:

treating relapses of MS symptoms (with steroids)
treating specific MS symptoms
treatment to reduce the number of relapses (disease-modifying therapies)

The patient will be supported by a team of different healthcare professionals working together. This may include a neurologist (specialist in treating conditions of the nervous system), a physiotherapist, a speech and language therapist, and several other professionals. The team will also include a specialist MS nurse, who will usually serve as the main point of contact.

The symptoms of MS can be treated individually:

Fatigue
Many people with MS experience fatigue. You may be prescribed a medicine called amantadine for fatigue caused by MS, although this may only have a limited effect. You should also be given general advice on ways to manage fatigue, such as:

regular exercise
keeping healthy sleep patterns
energy-saving techniques
avoiding medicines that can worsen fatigue (including some painkillers)

Specialist fatigue management courses or therapy, such as cognitive behavioural therapy (CBT), can also help some people with MS cope with their fatigue. Your doctor may also look at whether anything else might be causing your fatigue, such as depression, trouble sleeping or a medical condition such as anaemia. They can then offer treatment if needed.

Visual problems
MS-related visual problems will often improve on their own, usually within a few weeks, so you may not need any treatment. If your symptoms are particularly severe, you may be prescribed steroids to help speed up recovery. If you have problems with involuntary eye movements, medicine such as gabapentin can sometimes help. Some people with double vision need help from ophthalmologists (eye specialists).

Muscle spasms and stiffness
Muscle spasms and stiffness (spasticity) can be improved with physiotherapy. Techniques like stretching exercises can help if your movement is restricted. If your muscle spasms are more severe, you may be prescribed a medicine that can relax your muscles. This will usually be either baclofen or gabapentin, although there are alternative medicines, such as tizanidine, diazepam, clonazepam and dantrolene. These medicines all have side effects, such as dizziness, weakness, nausea and diarrhoea, so discuss which would be best for you with your specialist MS nurse or GP.

If these medicines are not effective, you may be offered a 4-week trial of nabiximols (Sativex). This is a cannabis-based medicine sprayed into the mouth. If medicines do not help, you may be referred to a specialist service that helps people manage muscle spasms and stiffness, called a spasticity service.

Mobility problems
Mobility problems are often the result of muscle spasms and spasticity, but they can also be caused by muscle weakness, or problems with balance or dizziness. If you have problems with mobility, you might benefit from:

treating relapses of MS symptoms (with steroids)
treating specific MS symptoms
treatment to reduce the number of relapses (disease-modifying therapies)

An occupational therapist can carry out an assessment of your home and suggest adaptations that may help.

Neuropathic pain
Neuropathic pain is caused by damage to your nerves and is usually sharp and stabbing. It can also occur in the form of extreme skin sensitivity or a burning sensation. This type of pain can be treated using medicines such as duloxetine, gabapentin or carbamazepine, or with a medicine called amitriptyline – an older type of antidepressant, but these days it’s mainly used for pain control.

Musculoskeletal pain
Living with MS can cause stresses and strains to the muscles and joints in your body. A physiotherapist may be able to help with this pain by suggesting exercise techniques or better seating positions. If your pain is more severe, you may be prescribed painkillers. Alternatively, you may have a device that stimulates your nerves called a transcutaneous electrical nerve stimulation (TENS) machine.

Problems with thinking, learning and memory
If you experience problems with thinking and memory, you may be referred to a neuropsychologist and an occupational therapist, who can help assess your problems and suggest ways to manage them.

Emotional problems
If you experience emotional outbursts, such as laughing or crying for no apparent reason, you should be assessed by a specialist such as a clinical psychologist. They may suggest treatment with an antidepressant. People with MS who have depression can also be treated with antidepressants or therapy, such as CBT. If you often feel anxious or worried, you may be prescribed antidepressants or benzodiazepines, a type of tranquilliser that has a calming effect.

Sexual problems
Men with MS who find it hard to obtain or maintain an erection (erectile dysfunction) may be prescribed medicine to temporarily increase the blood flow to the penis, such as sildenafil (Viagra). The NHS provides this if you have MS. Relationship counselling or seeing a sex therapist may also help both men and women with MS who have problems with reduced interest in sex or difficulty reaching orgasm.

Bladder problems
Various medicines are available if you have an overactive bladder or need to urinate frequently during the night.

If you find it difficult to empty your bladder or you leak urine, advice from a continence nurse or physiotherapist can help. Occasionally, a catheter can be used to empty the bladder when needed. In rare cases, people with MS may need a long-term catheter to keep the bladder emptying safely. You may be referred to a continence adviser or urologist, who can offer specialist treatment and advice, such as botulinim toxin injections, bladder exercises or electrical treatment for your bladder muscles.

Bowel problems
It may be possible to treat mild to moderate constipation by changing your diet or taking laxatives. More severe constipation may need to be treated with suppositories or an enema. Bowel incontinence can sometimes be treated with anti-diarrhoea medicine or by doing pelvic floor exercises to strengthen your rectal muscles.

Speech and swallowing difficulties
A speech and language therapist can help you find ways to overcome problems with speech and swallowing.

For example, they can offer advice about foods that are easy to swallow and recommend exercises to strengthen the muscles used in speech and swallowing. If swallowing problems become very severe, some people need to be fed using a tube fitted into the stomach through the skin.

Disease-Modifying Therapies^[13]Although MS can’t be cured, there are medicines that can help people have fewer and less severe relapses. These are called disease-modifying therapies. They are taken either as a pill, an injection or an infusion. They aim to reduce the amount of damage and scarring to the myelin sheath (a layer surrounding your nerves), which is associated with MS relapses.

These treatments may also help to slow worsening disability in MS, although definitive research into their long-term benefits is limited.

Disease-modifying therapies aren’t suitable for everyone with MS. They’re only prescribed to those with relapsing-remitting MS or some people with primary or secondary progressive MS who have relapses.

People with progressive MS who don’t have relapses are very unlikely to benefit from the treatments and could still experience side effects from them.

You can find further information about disease-modifying therapies on these websites:

MS Society: Disease-modifying therapies: https://www.mssociety.org.uk/about-ms/treatments-and-therapies/disease-modifying-therapies
MS Trust: Disease-modifying drugs: https://www.mstrust.org.uk/understanding-ms/ms-symptoms-and-treatments/ms-decisions/disease-modifying-drugs

Treatment for Multiple Sclerosis Relapses^[14]Contact your specialist MS nurse or GP if you think you’re having a relapse. A flare-up of symptoms can sometimes be caused by something other than a relapse, such as an infection, so your nurse or GP needs to check for other possible causes. Treatment for a relapse usually involves either:

a five-day course of steroid tablets taken at home
injections of steroid medicine given in hospital for three to five days

Steroids can help speed up your recovery from a relapse, but they don’t prevent further relapses or stop MS from getting worse over time. They’re only given for a short period to avoid possible steroid side effects, such as osteoporosis (weak bones), weight gain and diabetes, although some people will still experience problems. Not using steroids more than three times a year (if possible) will also help reduce the risk of side effects.

Myelin – what is it, and what does it do?^[15]Myelin is a lipid-rich material that surrounds nerve cell axons^[16] (the nervous system’s “wires”) to insulate and increase the rate at which electrical impulses (called action potentials) are passed along the axon.^[17]

The ‘myelinated’ axon can be likened to an electrical wire (the axon) with insulating material (myelin) around it. However, unlike the plastic covering on an electrical wire, myelin does not form a single long sheath over the entire length of the axon. Rather, myelin sheaths the nerve in segments: in general, each axon is encased with multiple long myelinated sections with short gaps in between them called nodes of Ranvier.

A picture containing dark

Description automatically generated
Picture Credit: Action potential propagation in myelinated neurons is faster than in unmyelinated neurons because of Saltatory conduction. Attribution: Dr Jana, CC BY 4.0 <https://creativecommons.org/licenses/by/4.0>, via Wikimedia Commons. https://upload.wikimedia.org/wikipedia/commons/4/48/Saltatory_Conduction.gif

Myelin is formed in the central nervous system (CNS) – the brain, spinal cord and optic nerve. In the CNS, axons carry electrical signals from one nerve cell body to another. In the PNS, axons carry signals to muscles and glands or from sensory organs such as the skin peripheral nervous system (PNS).

Myelin reduces the capacitance^[18] of the axonal membrane. The discontinuous structure of the myelin sheath results in saltatory conduction, whereby the action potential “jumps” from one node of Ranvier, over a long myelinated stretch of the axon called the internode, before “recharging” at the next node of Ranvier and so on, until it reaches the axon terminal.^[19]

Once it reaches the axon terminal, this electrical signal provokes the release of a chemical message or neurotransmitter that binds to receptors on the adjacent post-synaptic cell (e.g., nerve cell in the CNS or muscle cell in the PNS) at specialised regions called synapses. The “insulating” role for myelin is essential for normal motor function (i.e. movement such as walking), sensory function (e.g. hearing, seeing or feeling the sensation of pain) and cognition (e.g. acquiring and recalling knowledge). Multiple Sclerosis, which specifically affects the central nervous system (brain, spinal cord and optic nerve), is the best-known disorder of myelin.

Picture Credit: A neuron cell diagram, cropped to show oligodendrocyte and myelin sheath. Public Domain, via Wikimedia Commons.
Attribution: Neuron_with_oligodendrocyte_and_myelin_sheath.svg: *Complete_neuron_cell_diagram_en.svg: LadyofHats derivative work: Andrew c.
File URL: https://upload.wikimedia.org/wikipedia/commons/a/a8/Neuron_with_oligodendrocyte_and_myelin_sheath.svg

Myelin is the sleeve of fatty tissue that protects and insulates nerve fibres, like insulation around a wire. Myelin helps electrical signals travel along nerve fibres. Damage to myelin and nerve fibres is called demyelination. The tissue that results is scarred and called sclerosis^[20].

Causes of Multiple Sclerosis^[21]It’s unclear what causes the immune system to attack the myelin sheath. Thus far, research suggests that it is likely to be partly caused by genes inherited from parents and partly by outside factors that may trigger the condition.

The NHS says that some of the factors that have been suggested as possible causes of MS include:

Your genes – MS isn’t directly inherited, but people related to someone with the condition are more likely to develop it; the chance of a sibling or child of someone with MS also developing it is estimated to be around two to three in 100.
Lack of sunlight and vitamin D: MS is more common in countries far from the equator, which could mean that a lack of sunlight and low vitamin D levels may play a role in the condition, although it’s uncertain whether vitamin D supplements can help prevent MS.
Smoking – people who smoke are about twice as likely to develop MS than non-smokers.
Teenage obesity – people who were obese during their adolescent years have an increased risk of developing MS.
Viral infections – it’s been suggested that infections, particularly those caused by the Epstein-Barr virus (responsible for glandular fever), might trigger the immune system, leading to MS in some people.
Being female – women are two to three times more likely to develop MS than men; again, the reason for this is unclear.

More research is needed to understand more about why MS occurs and whether anything can be done to prevent it.

Further information on the causes of MS is available from the MS Society.^[22]

Picture Credit: “Denny drops in” by EasyStand is marked with CC BY-NC-ND 2.0.

Conclusions^[23]

Most MS patients are diagnosed between the age of 20 and 50.
Vision problems are often the first symptom.
About 80% of patients have relapsing-remitting MS – marked by alternating periods of symptoms and recovery.
If you have relapsing MS and you stop smoking, it can slow down how quickly your MS might change to secondary progressive MS.
MS occurs in almost all ethnic groups, but it is more common among white people with Northern European ancestry.
Countries, where MS is more common include Canada, the US, Scandinavia, southern Australia and New Zealand.
MS is more common in areas that are furthest from the equator. But not everyone in the same geographical area is equally at risk. Some groups living very far north, such as the Inuit of the North American Arctic, for example, seldom develop MS.

Sources and Further Reading

Picture Credit: Jean-Martin Charcot, Unidentified photographer, Public domain, via Wikimedia Commons.
File URL: https://upload.wikimedia.org/wikipedia/commons/6/6a/Jean-Martin_Charcot.jpg

Jean-Martin Charcot
Jean-Martin Charcot was a French neurologist who defined and gave a name to multiple sclerosis in 1868. Throughout the 1800s and 1900s, hundreds of therapies were tried, without success, to treat the condition.

Charcot’s studies between 1868 and 1881 were a landmark in understanding Parkinson’s disease.^[24]

The first description of multiple sclerosis in patients in Britain was published by William Moxon in 1873 and in the US by Dr Edward Seguin in 1878, although in both countries, earlier cases had been reported but not identified.

CAUTION: This paper is not medical advice. No advice is implied or given in articles published by us but is only for general information. You should always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. This paper is compiled from the sources stated but has not been medically reviewed. It should never be used as a substitute for obtaining advice from your Doctor, a consultant Neurologist or or other qualified clinician/medical practitioner. If you have already been given dietary advice, you should not make changes without first talking to your GP, consultant or dietitian. Any medications mentioned may include names for US drugs which may have a different name to those available in the UK. The facts are believed to be correct as at the date of publication, but there may be certain errors and omissions for which we cannot be responsible. There is no implied endorsement or promotion of any organisation by the writer. The hyperlinks were valid at the date of publication.

Source: https://www.healthline.com/health/multiple-sclerosis/physiological-changes#central-nervous-system ↑
Sources: https://mstrust.org.uk/about-ms/ms-symptoms-and-relapses/signs-and-symptoms and https://mstrust.org.uk/about-ms/ms-symptoms-and-relapses/signs-and-symptoms and https://mstrust.org.uk/about-ms/ms-symptoms-and-relapses/signs-and-symptoms#early-signs-of-ms ↑
Source: Dyment DA, Ebers GC, Sadovnick AD (February 2004). “Genetics of multiple sclerosis”. The Lancet. Neurology. 3 (2): 104–10. CiteSeerX 10.1.1.334.1312. doi:10.1016/S1474-4422(03)00663-X. PMID 14747002. S2CID 16707321. ↑
Source: Skene NG, Grant SG (2016). “Identification of Vulnerable Cell Types in Major Brain Disorders Using Single Cell Transcriptomes and Expression Weighted Cell Type Enrichment”. Frontiers in Neuroscience. ↑
Source: Compston A, Coles A (April 2002). “Multiple sclerosis”. Lancet. ↑
See: Genetics at: citations – https://en.wikipedia.org/wiki/Multiple_sclerosis ↑
Source: https://my.clevelandclinic.org/health/diseases/17248-multiple-sclerosis ↑
Source: https://my.clevelandclinic.org/health/diseases/17248-multiple-sclerosis ↑
Source: https://en.wikipedia.org/wiki/Myelin ↑
Definition from https://www.britannica.com/science/axon: Most axons of humans are enclosed in a myelin sheath, which increases the speed of impulse transmission; some large axons may transmit impulses at speeds up to 90 metres (300 feet) per second. ↑
Source: Bean, Bruce P. (June 2007). “The action potential in mammalian central neurons”. Nature Reviews Neuroscience. 8 (6): 451–465. doi:10.1038/nrn2148. ISSN 1471-0048. PMID 17514198. S2CID 205503852 ↑
Capacitance is the ability of a component or circuit to collect and store energy in the form of an electrical charge. ↑
Reference Sources: (1) Carroll, SL (2017). “The Molecular and Morphologic Structures That Make Saltatory Conduction Possible in Peripheral Nerve”. Journal of Neuropathology and Experimental Neurology. 76 (4): 255–257. doi:10.1093/jnen/nlx013. PMID 28340093. (2) Keizer J, Smith GD, Ponce-Dawson S, Pearson JE (August 1998). “Saltatory propagation of Ca2+ waves by Ca2+ sparks”. Biophysical Journal. 75 (2): 595–600. Bibcode:1998BpJ….75..595K. doi:10.1016/S0006-3495(98)77550-2. PMC 1299735. PMID 9675162. (3) Dawson SP, Keizer J, Pearson JE (May 1999). “Fire-diffuse-fire model of dynamics of intracellular calcium waves”. ↑
Source: https://en.wikipedia.org/wiki/Myelin ↑
At : MS Society: Causes of MS – https://www.mssociety.org.uk/about-ms/what-is-ms/causes-of-ms ↑
Source: https://www.ohsu.edu/brain-institute/understanding-multiple-sclerosis ↑
Source: Lees AJ (September 2007). “Unresolved issues relating to the shaking palsy on the celebration of James Parkinson’s 250th birthday”. Mov. Disord. 22 (Suppl 17): S327–34. doi:10.1002/mds.21684. PMID 18175393. S2CID 9471754. ↑

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Understanding Multiple Sclerosis

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Understanding Multiple Sclerosis

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