What is MS and what causes MS?
What is MS?
Multiple Sclerosis (MS) is a neurological condition which affects the central nervous system (the brain and spinal cord).
Sclerosis means 'scarring' and refers to the areas of the brain or spinal cord which have been affected by MS. Multiple because these generally happen in more than one place.
No two people with MS are the same – the symptoms people experience will relate to where and how many areas in their central nervous system are affected.
Most people are diagnosed in their 20s or 30s but MS can be diagnosed in people younger or older than this.
It is estimated that there are around 150,000 people with MS in the UK and, although there is not yet a comprehensive registry of people with MS, we believe that there are around 2260 people living with MS in Dorset.
What happens in MS?
Our nerves work very similarly to an electric cable. In an electric cable, current passes though the wire from one end to another. The plastic covering helps to prevent damage and insulates the wire so that it doesn't short circuit.
Myelin is the covering of a nerve and acts like the plastic covering on a cable – it protects the nerve fibres from damage and allows messages to be passed along the nerves quickly and without being interrupted.
Damage to myelin and nerve fibres leads to messages being slowed down or not getting through. This causes the symptoms people experience in MS. The specific symptoms that appear depend on the role of the damaged nerve and which bit of the brain or spinal cord it is in.
What causes MS?
We don't know exactly what causes MS, but it's likely to be a mix of things like your genes, your environment, and your lifestyle. It is likely that several different things need to come together to trigger MS. Not enough is known yet to be able to know who will or won't get MS.
The most agreed theory is that MS is an autoimmune disorder. This means that the body's natural defences can't tell the difference between its own cells and foreign invaders (such as bacteria), which leads to the nerve cells being attacked in MS.
Risk factors
Genetics
MS is not considered hereditary (directly passed from parent to child). There is no one gene that directly causes MS, but over 230 genes have been found which increase the risk of developing MS to a small degree.
Because family members share some of the same genes, this does mean that there is a higher risk of developing MS if you have a family member with it.
When a parent has MS then approximately 98% of children will not develop MS. When both parents have MS approximately 80% of children will not develop MS.
Geography
MS is more common in countries further away from the equator. The further north or south you go from the equator the chance of developing MS increases. It is not known exactly why this is, but it may be related to the level of Vitamin D you absorb in the warmer climates versus the colder ones. Or it may be related to the type of viruses that live in the colder countries and the risk of being exposed to one of those viruses as a child or teenager.
Vitamin D
The role of Vitamin D is largely unknown, however, it is essential for immune system regulation and bone health.
Research has shown that low levels of Vitamin D are linked with an increased risk of getting MS, and with more frequent relapses in people who have MS.
Viruses/Epstein Barr Virus (EBV)
It has been suggested that the autoimmune behaviour found in MS could be caused by a virus.
The Epstein Barr Virus (EBV) is a common virus that causes glandular fever (typically in children or teenagers). Once EBV is acquired, it is carried for life, usually with no harmful effects.
There is evidence to suggest a possible link between MS and EBV. Having EBV doesn't mean you will get MS (over 90% of the population worldwide has been infected with EBV), but there is research which suggests virtually everyone with MS has had EBV infection.
Smoking
There are several studies which have shown that if you smoke, this adds to the risk of you developing MS.
Smoking can make MS worse. Please see the following links for more information:
Obesity
Studies have shown that being overweight as a child or teenager leads to an increased risk of developing MS.
Having a higher body mass index (BMI) has been associated with several changes in the body and more research is needed to identify which of these could contribute to the development of MS.
More information on living well with MS can be found in Living Well with MS.
More information about what MS is and what causes it can be found on the MS Trust and MS Society websites:
