Multiple sclerosis (MS) is an immune-mediated disease affecting the brain and spinal cord, collectively known as the central nervous system (CNS).
In people with MS, the communication of nerve impulses along nerve cells within the CNS is disrupted. This occurs when the protective layer (also called myelin) surrounding the nerve cells that normally speeds up transmission of nerve impulses, is attacked by the immune system.
Repeated immune attacks can prevent the proper repair of myelin, and in some cases, cause damage to the nerve cells themselves, resulting in permanent injury to the brain and spinal cord.
The nature and severity of symptoms vary from person to person. Even within the same individual, the characteristics of attacks (also known as relapses) can differ depending on which part of the CNS is being affected and the extent of myelin and/or nerve cell damage.
Relapses usually last for a couple of days to a week and are followed by an improvement in symptoms. Temporary worsening of signs and symptoms of MS can sometimes occur with a rise in body temperature (for example, during infections) but these do not count as a true relapse.
The disease course is highly variable – no two individuals have the exact disease course. Over time, some people with MS may not recover fully from relapses whilst others may develop a gradual but steady progression of signs and symptoms without any apparent relapses.
Nevertheless, many people with MS continue to lead normal, productive lives and have prolonged periods of time when they are symptom-free.
Symptoms of MS may include
The cause of MS is currently unknown. However, there are several factors which may increase the risk of developing MS.
Our bodies have a built-in defence system (the immune system) to fight infections caused by viruses and bacteria. Sometimes, this defence system starts attacking healthy cells in the body instead. This reaction, termed an autoimmune response, can cause MS when the body attacks nerve cells and myelin by mistake.
A defect in genes that control immune reactions or those that make up the CNS can increase the risk of developing MS. If you have a parent or sibling diagnosed with MS, you are at a slightly higher risk of developing the disease.
Onset usually occurs between the age of 20 to 50. However, MS can sometimes affect children, teenagers and older people.
Women are more likely to develop MS than men (approximately 2 to 3:1). The risk of developing MS is not related to pregnancy and women with MS can have children.
MS occurs more often in people of Northern European descent, and in countries in Europe, North America, New Zealand and Australia. The closer the distance to the equator, the fewer the cases of MS reported. However, it does affect approximamtely more than 300 people in Singapore.
Lower exposure to sunlight and low levels of vitamin D have been associated with higher risk of developing MS.
A diagnosis of MS can be made through detailed history taking, clinical examination and tests.
Some of these tests include:
A range of medications is available to treat acute relapses, prevent relapses, delay disease progression and manage symptoms. All have been approved for use, although the efficacy and risks (e.g. infection) associated with each type of medication can vary. Your neurologist will discuss with you the benefits and risks of each treatment before prescribing medication to best suit your symptoms, stage of condition and unique needs.
Corticosteroids, also known as steroids or glucocorticosteroids, are prescribed during acute relapses to reduce the duration and severity of relapses. This is given via a drip into the vein (intravenously) usually for three to five days in the hospital, followed by a short course of oral corticosteroids upon discharge.
It is important to note that corticosteroids, especially at high doses, are not to be used on a long-term basis as they can cause side effects such as osteoporosis and diabetes.
These medications are given to suppress inflammation in the brain and spinal cord, and have been shown to reduce relapse rates and disability.
There are now many new medications approved for this purpose, with differing effectiveness and side effects.
There is no ‘best’ drug for people with MS. The choice of medication is individualised and a decision should be made with your managing clinical team, taking into account factors such as degree of MS disease activity, type of MS, potential side effects, route of administration, child-bearing preferences, vaccination status and cost.
Types of immunomodulatory agents include:
Interferon-beta works mainly by reducing inflammatory molecules involved in MS while increasing anti-inflammatory compounds. It is given under the skin (subcutaneously), usually three times a week.
These medications reduce the number of activated immune cells and are taken orally on a daily basis.
These medications prevent activated immune cells from entering the brain and spinal cord.
Fingolimod and Siponimod are taken orally on a daily basis, while Natalizumab is given monthly via a drip into the vein (intravenous). There is a slight risk of infection although this can be reduced by blood and imaging monitoring.
These medications reduce B cells (a type of immune cell which play an important role in MS).
Rituximab and Ocrelizumab are given via a drip into the vein (intravenously) every six months, while Ofatumumab is administered under the skin (subcutaneously) monthly. There is a slight risk of infection although this can be reduced by blood monitoring.
Cladribine and Alemtuzumab are known as immune reconstitution therapies and work by first depleting the immune system, then allowing the immune system to ‘reset’ and then recover ability to respond to infections. They are given yearly for two years – orally for Cladribine and via a drip into the vein (intravenously) for Alemtuzumab. There is a slight risk of infection although this can be reduced by blood monitoring.
Autologous haemopoietic stem cell transplantation is also a type of immune reconstitution therapy and involves chemotherapy to deplete harmful immune cells then allowing the immune system to ‘reboot’ and recover using stem cells taken from the blood of the same patient.
This is a highly specialised procedure and for patients who do not respond to other treatments.
As symptoms of MS may persist even after a relapse, medications can be prescribed to manage symptoms such as pain, fatigue, stiffness, bowel and bladder issues, anxiety, depression and sexual problems.
Although these medications do not modulate the immune system, they are important in helping people with MS improve their quality of life.
Support for MS
MS Support Group – MS Care
A support group is available for people with MS. The aim of this support group is to provide peer support, education and health management tips. People with MS are also involved in various activities and exercises, and encouraged to share their personal experiences.
Volunteers in MS Care provide a support network for MS patients and caregivers by befriending them and providing relevant assistance. For more information, contact MS Care at 9825 6015.