With so many variables contributing to a person's potential to suffer from the chronic illness, multiple sclerosis, Vikki Tranter explores its causes, symptoms and underwriting implications
Multiple sclerosis (MS) is a disease of the nervous system that can cause a number of symptoms, including visual problems, muscle weakness and balance problems. It can also cause difficulties with co-ordination and speech, severe fatigue, numbness, pins and needles, aches and pains, concentration and memory problems, as well as problems with bowel and bladder control. It results in impaired mobility and, in severe cases, significant disability.
It is a chronic inflammatory disease affecting the central nervous system, which is characterised by scarring and loss of myelin - the protective sheath of fatty tissue that surrounds neurons (cells in the brain and spinal cord that carry information, create thought and perception and allow the brain to control the body). The symptoms that occur vary widely depending on which signals are affected.
Causes
The exact cause of MS is unknown but the predominant theory is that it results from attacks by an individual's immune system on the nervous system (an autoimmune disease). There is also research into the possibility that exposure to a virus may trigger the autoimmune process that results in MS. Another theory is that it is caused by a vitamin D deficiency. MS is more common in people who live further from the equator, due to decreased exposure to sunlight. Stress, lack of exposure to illness in childhood and smoking are also thought to be factors.
Genetics is also thought to play a role in a person's susceptibility to MS. If a person has a first-degree relative with the condition, then their chance of getting the disease is between 1% and 3% (in the population at large, the chance is less than one-tenth of a percent).
For identical twins, if one twin develops MS, the likelihood that the second twin will do so is 30%. There could be a combination of factors, which contribute to the development of MS.
Diagnosis
There is not one conclusive diagnostic test for MS and diagnosis is made by a conjunction of the following:
n Observation of signs and symptoms.
n Neurological examination with the neurologist looking for changes in eye movements, limb co-ordination, weakness, balance, sensation, speech and reflexes.
n Laboratory tests, MRI brain scan, which picks up lesions in the brain and lumbar puncture which takes fluid from the spinal cord from which abnormalities can be detected.
The course of MS varies significantly in each person. Some people are minimally affected while others progress rapidly to total disability. Most are in between the two extremes. Some people have an attack and then are free of symptoms for 10 years or longer. There are however a number of distinct patterns relating to the course of the disease and these are as follows:
n Benign MS, that starts with a small number of mild attacks followed by complete recovery.
n Relapsing-remitting MS, periodic attacks followed by periods of near remission.
n Progressive MS, which is characterised by chronic deterioration of the neurological status and carries a poorer prognosis.
There is no known cure for MS but certain therapies are helpful. Acute exacerbations are treated with oral steroids (Prednisilone). This medication can shorten the attack. The relapsing-remitting form is treated with Beta Interferon, which lessens the number of attacks and increases the time to chronic disability. The progressive form is treated with Interferons and Immunosuppressive drugs. There are also numerous other drugs to control the many symptoms - for example fatigue and incontinence.
Prognosis
The prognosis of the disease depends upon whether it is benign, relapsing remitting or progressive. In individuals with progressive disease, supportive equipment such as a wheelchair or standing frame is often needed after six to seven years, however when relapsing remitting it may be 20 years, which means that many may never need a wheelchair. Prognosis is better in those at younger age of onset, fewer systems involved, little disability and of female sex.
Vikki Tranter is life and disability underwriter at Aegon Scottish Equitable
