M.S affects the central nervous system (CNS). The CNS consists of the brain and spinal cord which are connected to cranial nerves (12 pairs) and spinal nerves (31 pairs). This network of nerves signals electrical and chemical messages to each other at great speed, controlling body functions.
In M.S, the myelin, the fatty protective sheath that surrounds the nerve fibres, becomes damaged. It can take some time to diagnose the condition as it takes several symptoms over different periods of time before further tests are undertaken and a diagnosis made.
Networks that send messages to the CNS in response to stimuli such as heat or pain are known as sensory nerves. Networks that transmit messages in the other direction from the CNS to peripheral organs and tissues are known as motor nerves. In M.S the messages going to and from the brain and spinal cord become distorted or slowed down, resulting in M.S symptoms.
Roughly 1 in 750 are diagnosed with the condition and more women have the condition than men. Some people experience ‘attacks’ which are the sudden onset of symptoms, but which fade after a few days or weeks. Sometimes medication or additional therapy is required to help the process. Others do not experience these attacks but do notice some deterioration over the years, but it is impossible to know what is going to happen in future years.
Symptoms are very varied and differ in everyone, but there are common trends and it is crucial to ensure that facilities are available to help them when required. Whether this be therapy, information or just support for the person with M.S, their carer or other family members.
Different types of Multiple Sclerosis
There are basically four types namely Benign, Relapsing / Remitting, Primary Progressive and Secondary Progressive.
Someone with a small number of relapses followed by a complete recovery may be described as having benign M.S. It is only possible to make a diagnosis of benign M.S once someone has experienced little or no disability for a period of 10 to 15 years. However, a relapse may occasionally occur after many years in which the M.S has been inactive.
The majority of people with M.S have a disease pattern with relapses (attacks) and remissions (passive periods). In a relapse, the M.S is active and nerves are being damaged – new symptoms may appear and existing ones worsen. A relapse may last only a few days, or continue for months. In remission the M.S symptoms may still be present because of the damage that has already occurred to the nerves. But these symptoms can often lessen, level off or improve during remissions – which can last for months or years. MRI findings have demonstrated that remission is the normal event with this M.S pattern.
With Primary Progressive M.S, symptoms steadily worsen; resulting in a continued progression in disability without distinct relapses and remissions.
This type of M.S is identified when a condition becomes steadily worse and disability progresses for a period of 6 months or more, whether or not they continue to have relapses. Most people who have relapsing/remitting M.S eventually develop secondary progressive.
The term ‘Sclerosis’ means scarring. Demyelination causes many scars or lesions in different places within the central nervous system. The symptoms that occur depend on the site and severity of the lesions and this is why people with M.S experience different symptoms at different times.
- Loss of vision, blurred or double vision
- Weakness of limbs
- Reduced co-ordination
- Balance problems
- Numbness, pins and needles
What causes M.S?
Although it is not yet certain why people develop M.S, research suggests that a combination of genetic and environmental factors are involved:
M.S is not directly inherited; however there does appear to be a genetic component – possibly a combination of certain genes – which makes people more susceptible. Family members of someone diagnosed with M.S have a slightly higher chance of developing M.S themselves.
Studies have found that the further north from the equator you live, the higher the chance of developing M.S. It appears that there is a higher rate of M.S in the UK (M.S is more common in Scotland than in the rest of the UK), North America and Scandinavia but a very low rate in countries like Malaysia which are very close to the equator. Some research suggests that there is a link between M.S and Vitamin D deficiency. Vitamin D mostly comes from exposure to sunlight so this could be a factor. Research on this matter is ongoing.
How is M.S diagnosed?
You will be referred to a neurologist who will look at your medical history and examine you. You are then likely to undergo a number of tests including:
- M.S MRI Scan – this will identify any areas of the brain or spinal cord that may have scarring.
- Lumbar Puncture – a lumbar puncture (also know as a spinal tap) is used to take a sample of spinal fluid to test for abnormalities.
- Evoked Potentials – simple tests that measure the time it takes for the nerves to respond to electrical stimulation.
A positive diagnosis can take some time and these tests are not always conclusive.