A common disease, yet still barely understood, Anne Llewellyn gives a guide to the underwriting of multiple sclerosis
Multiple sclerosis (MS) is the most common neurological disorder of young adults, usually being diagnosed between the ages of 20 and 40. The destruction of nerves causes loss of functional ability, the source of which is not fully understood and there is no cure.
MS is a disease of the central nervous system (the brain and the spinal cord). Nerve fibres are covered with a substance called myelin, which acts as an insulator and allows impulses to travel down the nerves quickly and efficiently. In MS, the myelin becomes inflamed and scarred, and is eventually destroyed - sometimes MS is referred to as demyelination for this reason. The nerve impulses become weaker as the myelin is less efficient, and may eventually fail altogether. Whatever is being controlled by the affected nerve will therefore become weaker and eventually the nerves will stop responding to the signals from the brain.
The cause of demyelination is unknown. It was thought to be solely an autoimmune disorder, which is where the body is effectively rejecting its own nervous system, but now it is thought it could be a genetic susceptibility combined with an infection which causes an autoimmune response.
MS is more common in women and there is also a very strong geographical distribution, with MS being virtually unknown in the southern hemisphere and the highest prevalences in Western Europe and North America.
The most common early symptoms of MS are visual disturbances (blurred or double vision, severe eye pain), sensory disturbances (tingling, pins and needles, numbness) and motor disturbances (limb weakness).
The visual disturbances can be due to optic neuritis, inflammation of the optic nerve, which is a condition in its own right. Although not everyone who has optic neuritis will go on to develop MS there is a strong link, with 40% of those with the condition going on to develop MS within five years.
There is no single definitive test to determine a diagnosis of MS, and while negative testing makes a diagnosis less likely, it does not rule it out. Currently, the most reliable test is a MRI (magnetic resonance imaging) scan of the brain and spinal cord. Areas of demyelination show up as white plaques, and over 90% of people with MS will have MRI scans that are positive for plaques.
Another test often carried out is an investigation for proteins in the cerebrospinal fluid, known as oligoclonal banding, through a lumbar puncture which can be painful. A totally painless and non invasive test is 'evoked responses' where the patient is wired to an encephalogram and the brain activity response to stimuli such as flashing lights is measured. MS is indicated by the time it takes for these messages to get through to the brain.
While there is actually no standard set of clinical rules for the diagnosis of MS, it is usually based on a series of guidelines called the McDonald criteria, which state that the symptoms must be disseminated in space (ie more than one set of symptoms) and time (ie more than one event). The symptoms must have lasted for more than 24 hours, and to qualify for being more than one event they must be 30 days apart. The McDonald criteria also heavily depend on MRI results. Various combinations of events in time, space and positive MRI results will lead to a diagnosis of MS although this is by no means clear cut, especially in the early stages of the disease - which can create problems when underwriting.
There are 79 conditions which mimic MS. Diagnostic evaluation strategies used to rule out alternative diagnoses depend on the following:
1. Where clinical, laboratory and imaging results show classic features of MS with no strong features of an alternative diagnosis: no further tests will be carried out.
2. Where features that are compatible with MS but are also red flags for other conditions, tests will be required to exclude alternative diagnoses.
3. If there are red flags which point to an alternative diagnosis and MS is improbable, an alternative diagnosis will be searched for.
There are four main sub-types of MS and the classification depends on the clinical course following diagnosis.
Relapsing remitting
About 85% of people with MS have this type. There are unpredictable periodic relapses, with interim periods of remission which may last months or years. During the attacks, the disease activity causes symptoms of visual, sensory and motor disturbances which may resolve during remission or be permanent to some degree. Where they are permanent, each relapse will leave the patient with increasingly impaired neurological function. A small number of people will have very long periods of remission with small relapses and complete recovery in between. This type is often referred to as 'benign' MS, but can only be described as such when this clinical course has been followed for 10 years.
Secondary progressive
This is where there is a relapsing-remitting onset but after a period of time there is a steady deterioration in neurological function with no periods of remission. About 50% of people with relapsing-remitting MS will go into the secondary progressive phase after 15 years. The decline may include new neurological symptoms, worsening cognitive function or other deficits. Secondary progressive causes the greatest degree of disability.
Primary progressive
About 10% of those diagnosed with MS have this type. The initial symptoms have an insidious and vague onset, followed by a steady decline in function with no periods of remission. Typically the age of onset is later, commonly around 40 years of age. In severe cases disability occurs within five years from the initial symptoms.
Progressive relapsing
This is the least common subtype which begins with a progressive course, but periodic attacks do occur as well.
At present no cure exists for MS so treatment is regarded as palliative. There are two basic strategies for treating multiple sclerosis: the first is to modify the course of the disease by controlling inflammation and formation of plaques typically through using steroids and/or beta interferon and the second is to treat the symptoms, such as using Baclofen for spasticity.
- Anne Llewellyn is underwriting training and development manager at PruProtect
Sources
RGA
Pacific Life Re
Gen Re
Hankgeorgeinc.com
Mssociety.org.uk
UNDERWRITING CONSIDERATIONS
With a condition that is difficult to diagnose, incurable, and with a very varied, unpredictable course it is not surprising that the underwriting outcome is also extremely varied. Terms can be anything from standard rates for benign MS to decline where progression has been rapid. It goes without saying that critical illness will be declined if a diagnosis of MS has been made.
Generally, terms are only available for the relapsing-remitting type of MS.
An underwriting assessment is made on the current degree of disability suffered by the client, categorised as mild, moderate or severe. There are a number of ways of doing this. A common one is to use the expanded disability status scale (EDSS), based on scoring eight functional systems for the degree of disability. The scale is 1-10 and the functional systems are: ability to walk; co-ordination; speech and swallowing; sensory (touch and pain); bowel and bladder functions; visual; mental or other.
An EDSS score of 2.5 is mild disability in one functional system or minimal disability in two functional systems. This equates to 'mild MS'. An EDSS of 5.0 is where the patient is able to walk without aid or rest for about 200 metres, but the disability is severe enough to impair full daily activities such as working for a full day without special provisions, and this can be regarded as 'moderate'. Anything above that would be regarded as severe and will usually be declined.
Assessment can be refined using prognostic indicators.
Good prognostic indicators: female, relapsing remitting onset, sensory symptoms (numbness/optic neuritis), complete recovery between relapses, infrequent relapses, few attacks early in course (less than four in two years), long time to permanent disability, young.
Poor Prognostic features: male, polysymptomatic onset, motor symptoms, incomplete recovery between relapses, frequent relapses, many attacks early in course (within six months), short time to permanent disability, older (over 40).
One of the biggest issues for underwriters is assessing a case where MS is suspected but not diagnosed, particularly when critical illness has been applied for. Where there is a disclosure of vague neurological symptoms such as pins and needles/tingling, numbness, blurred vision, bladder dysfunction, tremor, weakness and fatigue and others, it may mean that critical illness is declined, or multiple sclerosis is excluded.
Finally, there is a strong familial link as the table to the left shows:
For critical illness, family history is significant and depending on the combination of sex and family members affected, exclusion may be applied.
