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| Chronic fatigue syndrome (Myalgic encephalomyelitis) |
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Written by Dan Rutherford, GP
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The problem of ‘fatigue’
Fatigue is a very
common feeling that occurs in a host of circumstances, sometimes as a symptom
of illness, at other times as an emotion or as a reaction to life events.
Much confusion surrounds the medical use of the term ‘fatigue’.
Here we use the term ‘CFS/ME’ to refer to a profoundly disabling condition in
which there is marked difficulty in carrying out effort-related
tasks.
Its full title is ‘chronic fatigue syndrome/myalgic
encephalomyelitis’.
What is fatigue?
In normal circumstances the feeling of physical tiredness is
related to a cause such as excess effort. It may be enough to force us to rest
but it then improves in a short time.
Repeated physical effort tends to improve our fitness and
ability to carry out heavy or sustained work. The severity and impact of the
symptoms experienced by the majority of people with CFS/ME is vastly greater
than the symptoms of what one might call ‘ordinary’ fatigue.
There is usually a delay of anything from hours to days between
the effort and the exhaustion in CFS/ME and repeated activity does not lead to
adaptation and improvement in strength or stamina – usually the reverse occurs.
The size of the problem
CFS/ME is a major world-wide public health problem. There are
considerable difficulties in establishing good figures for the number of people
affected, but accepting that the figures are approximate, the following
generalisations can be made regarding the UK:
-
CFS/ME affects between 2 and 4 people per 1000 of the
population
-
it affects people of all ages, including children as young as
five years old
-
the commonest age of onset is between the early twenties to
mid-forties
-
CFS/ME is diagnosed about twice as often in women compared to
men
-
it affects all social classes.
There are therefore as many as 200,000 people with CFS/ME in the
UK alone – a staggering number for a condition that has attracted so little
serious enquiry until recently.
Definitions
From the point of view of conducting research on a condition, it
is essential that agreement exists on what it is that is being studied, or
conclusions made in one centre will have no relevance to anywhere else.
Several groups around the world have therefore worked to produce
definitions of CFS/ME that attempt to encapsulate the necessary features of the
condition. The most widely used are those of the Centre for Disease Control
(1994) in the USA, which are:
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Fatigue of definite or new onset that is not the result of
exertion, is not significantly improved by sleep or rest and which results in
substantial reduction in overall performance for a consecutive period of six
months or longer.
Plus at least four from the following list:
-
self-reported significant impairment of short term memory or
concentration.
-
sore throat.
-
tender lymph glands (small swellings under the skin which are
part of the immune system) in the neck region or under the armpits.
-
muscle pain.
-
headaches of a new type, pattern or severity.
-
unrefreshing sleep.
-
malaise following effort that lasts more than 24 hours
-
pains in several joints occurring without joint swelling or
redness.
There are several problems using such a system as this. For a
start the requirement for the fatigue to be present for six months takes no
account of the fact that the disability from CFS/ME starts on day one of the
illness, which is often abrupt.
In practice no caring doctor would wave a patient out of the
consulting room and ask them to make an appointment once the six months were up
so that he could then start discussing the symptoms for real.
In the early weeks of CFS/ME it can be difficult or impossible
to distinguish it from other conditions that can cause similar symptoms but
which have a different outcome, and it is necessary to search for these. The
purpose of these diagnostic criteria therefore should be seen as mainly an aid
to research. People who fulfil them are therefore similar at least to a certain
extent, so it becomes possible to compare how they fare with different types of
treatment.
It is quite possible to have CFS/ME and not have all of these
symptoms – an individual’s experience of CFS/ME is essentially
unique.
International criteria
The ‘Oxford Criteria’ (1990) therefore defined CFS/ME as a
syndrome in which:
-
there is a definite onset (ie it is not lifelong)
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fatigue is the main symptom
-
the fatigue is severe, disabling and affects both physical and
mental functioning
-
the fatigue has been present for at least six months, during
which time it has been present more than 50 per cent of the time
-
other symptoms may be present, particularly myalgia, mood and
sleep disturbance.
Tests
In making a diagnosis of CFS/ME it is important to exclude other
conditions that can cause some or all of the symptoms although there are really
no other conditions that look exactly like it in all its aspects.
Fatigue, of a generally smaller degree is however a common
accompaniment of
anaemia (lack of
blood),
underactivity of the thyroid
gland,
diabetes, disturbance of kidney or
liver function and persistent infection, especially with some viruses and more
unusual bacterial infections.
Rarer causes include immune system diseases such as lymphoma,
‘auto-immune’ diseases such as SLE (systemic lupus erythematosus) in which many
organs become inflamed, or underproduction of hormones from the pituitary gland
of the brain.
Simple
blood and
urine tests can
screen for the majority of these conditions and are well within the scope of
the GP to arrange.
The diagnostic approach
In the majority of people who have CFS/ME it is possible to make
a positive diagnosis of the condition based on its own features, in which case
extra tests help to confirm that nothing else has been missed.
An unhelpful line of thinking among ‘dinosaur doctors’ is to say
to a fatigued patient, on receipt of a normal set of blood reports, that there
is ‘nothing wrong’.
To the patient sitting in the chair and feeling completely
whacked by the effort of getting to the surgery nothing could be more obviously
wrong with such a view.
Impact of CFS/ME
If you are reading this as someone who has or had CFS/ME you
will need no expansion on the subject of how dramatic and devastating its
impact can be.
Although it is part of the diagnostic criteria for CFS/ME that
it should significantly impair performance intellectually and socially, these
few words hardly do justice to just how much CFS/ME can change someone’s life.
The level of impairment caused by CFS/ME can vary from fairly
modest, in which an affected person can retain the ability to carry out most
normal duties including work, provided this is paced and sufficient rest is
allowed for through to the most severely affected people who can be bed bound
and need total nursing care. CFS/ME can last for months to many
years.
Treatments for CFS/ME
A
detailed technical report on CFS/ME treatments was
published by the National Health Service Centre for Reviews and Dissemination
at the University of York in September 2002.
Treatments can be grouped under several general headings:
-
Behavioural:
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cognitive behaviour therapy (CBT)
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graded exercise and pacing.
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Immune system.
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Drug therapies:
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antiviral
-
antidepressants
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sleep promotion (hypnotics)
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steroids and other hormones.
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Dietary supplements.
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Complementary medicine.
Behavioural
The basic principle underlying behavioural treatments states
that being ill can be prolonged by wrongly held beliefs concerning the illness,
and that modifying these beliefs and the behaviour that stems from them will
make a person feel better.
Cognitive behavioural therapy (CBT)
The primary type of this treatment is called ‘cognitive
behavioural therapy’, or CBT, and a few studies have shown it to be an
effective way to achieve improvement in CFS/ME, at least for some people.
However CBT has had a mixed reception from some experts and many patients, for
several reasons.
If CBT is taken to imply that CFS/ME is ‘just psychological’
or ‘all in the mind’ then of course it would deserve to be treated with
contempt. If one drops that idea but instead accepts the more helpful view that
human behaviour is extremely diverse then it makes sense that when ill it is
possible to get into a frame of mind that can amplify or create problems.
Behaviour therapists do not say that they can explain why CFS/ME starts in the
first place, only that they have a system of tackling its effects.
The main difficulty with CBT is that it generally requires
to be carried out in conjunction with a therapist. 10 to 20 one-hour sessions
would be the norm, with ‘homework’ to be done between sessions. This of course
is a major stumbling block, because the number of suitably trained therapists
(usually psychologists) working within the NHS is small and waiting times of
over a year are not uncommon.
Provided it is approached in a positive way CBT will not
make anyone worse, but it won’t always help either. It can’t be reliably
predicted who will and won’t benefit.
Graded exercise
Some confusion exists about what exactly is meant by this.
It is clear that many people with CFS/ME who try to keep going at their old,
pre-illness pace, or who push themselves hard in an effort to force recovery
can cause themselves more harm than good in the short term as they are likely
to activate more symptoms.
Similarly it is too simple to say that someone with CFS/ME
who has become very sedentary and therefore has become unfit, needs to get
fitter to get better.
Re-training the body to cope with more effort is a two edged
sword and needs to be approached with care and common sense.
Graded exercise is therefore not the same as the ‘pull up
your socks and get on with it’ type of advice that is insulting to patients and
doesn’t work anyway.
Furthermore graded exercise has to be sensitive to the
individual’s particular circumstances – it is generally not helpful to give the
same programme of steadily increasing activity to everyone.
Two or three of the reasonably large trials done in graded
exercise showed benefit. The ways in which the trials were conducted were based
on set increases in exercise over several weeks rather than a totally flexible
system of pacing and some of the studies had quite high drop-out rates. On
balance graded exercise is a valid form of treatment for some people.
Pacing
Pacing means living within a given envelope of activity
defined on the basis of how much someone can do comfortably. By managing their
energies conservatively they can therefore extend their periods of activity.
Rest periods are important and with the passage of time one
should see improvement.
Pacing makes a lot of common sense yet seems to have drawn
criticism from some experts, who feel it can reinforce patterns of ill health
or discourage rehabilitation. Surely this need not be so. Very few people with
CFS/ME can be keen to keep feeling unwell and the vast majority are looking for
treatment or at least support on the way out of the illness.
If pacing is taken to mean permanent advice never to exceed
a certain level of activity defined at the start of the illness then the
criticism is justified – the concept of eventual improvement is essential to
motivate and encourage someone, especially during the bad spells. But bad
spells do occur and a sensible approach to rest, recuperation and moving on
again positively makes good sense.
Immune system
As subtle abnormalities of the immune system have been
proposed as possible causes of CFS/ME several types of treatment have been
tried that one way or another have immune system effects. The results have been
disappointing, although not entirely negative. Injection of antibody protein
(immunoglobulin G, IgG) was tested in several trials, some of which showed
partial benefit, others showed none and all had significant side effects from
the treatment.
As immunoglobulin is prepared from donated blood there is a
small risk of transmission of infection from it.
Ampligen is an expensive drug still under evaluation in CFS/ME
but in the one published trial so far it showed benefit and was well tolerated.
It is not available in the UK and there is insufficient information to
recommend it.
Drug therapies
Antiviral
The logic behind using antiviral treatment stems from the
possible role of virus infection in causing CFS/ME.
Interferon is a protein produced naturally by the body
during viral infections which has antiviral and immune system actions. It can
now be manufactured artificially and has several uses in medicine such as in
the treatment of hepatitis B and C virus infections. Two studies of interferon
in CFS/ME reported some improvement, but not in all those treated.
The antiviral drug aciclovir is not effective in
CFS/ME.
Antidepressants
There are several reasons why it can be worthwhile to use an
antidepressant in CFS/ME. Several symptoms of depression, such as fatigue and
sleep disturbance are also found in CFS/ME and it is theoretically likely that
there are some similarities in the brain chemistry changes underlying both
conditions.
The overlap is probably small as only a small proportion of
people with CFS/ME benefit from antidepressants unless they also have other
symptoms of a depressive illness.
As with depressive illness any benefit could take several
weeks to materialise but if there is no effect at about six weeks then there is
little point in persevering.
Sleep promotion
Sleep deprivation is an effective form of torture and
conditions or circumstances associated with disruption to sleep are invariably
associated with fatigue.
Although a great deal of information is now known about the
changes within the body and the brain that occur during sleep we have only a
patchy idea of why sleep is so important.
A simple explanation is that during sleep the electrical and
chemical functions of the brain and nervous system are reset and recalibrated
ready for the next wave of wakefulness and the levels of messenger chemicals
within the system are replenished.
A technological analogy is of a sophisticated computer
system updating its data and clearing the clutter out of its memory to allow
space for the barrage of information we take in constantly when
awake.
There is more to getting a good night’s sleep than not being
awake for a few hours which is probably why medicines to make people sleep
(hypnotics) can have disappointing results. The sleep thus gained is not
necessarily refreshing – a point often remarked upon by people with CFS/ME.
There is also the grogginess factor of still having some
drug in the system in the morning. Most of all there are the problems of long
term dependence on hypnotics. However, if someone has a particularly difficult
time getting to sleep without medication then taking a regular hypnotic is
probably the lesser of two evils.
Steroids and other hormones
There are many naturally occurring hormones in the body that
collectively come under the heading of ‘steroids’. Usually the term refers to
those hormones produced by the adrenal glands – two walnut-sized pieces of
highly specialised tissue that are situated at the top of each kidney.
The steroids produced here have very important roles in
controlling salt and water balance, blood pressure and general metabolism.
Failure of steroid production by the adrenal glands gives rise to a rare
condition in which fatigue is prominent.
The adrenal glands are controlled by other hormones arising
in the pituitary gland of the brain, and some evidence exists that points to
abnormalities in pituitary gland function as being a cause of CFS/ME.
Significant steroid deficiencies have not been found however, nor have trials
of steroid drugs been shown to be significantly beneficial.
Sex hormones are also steroids, produced by the ovaries or
testes. Again no evidence exists to tie changes in sex steroid levels to
CFS/ME.
Some women with CFS/ME may experience a change in the level
of symptoms during the course of their menstrual cycle or during pregnancy.
Changing sex hormone levels, for example with hormone replacement therapy, does
not help.
Dietary and vitamin supplements
In one trial comparing injections of magnesium with placebo
(dummy treatment) over six weeks the treatment group had a significantly better
outcome. In another study levels of magnesium within the red cells of the blood
were low in CFS/ME, but other studies have not confirmed this.
Evening primrose oil has produced conflicting results, with
one study reporting benefit after three months of taking 4g daily and another,
using the same dose, showing no benefit.
Vitamin B12 is essential for the manufacture of red blood
cells and the maintenance of the ‘insulating’ material that covers nerve tissue
(myelin). It is absorbed from foods of animal origin in the presence of a
substance called intrinsic factor normally made by cells in the stomach lining.
Intrinsic factor binds to vitamin B12 first in the stomach and
the combination is then absorbed downstream in the small bowel. Vitamin B12 is
stored in the liver and at any one time we have about three years’ supply
there. Detectable vitamin B12 deficiency is uncommon and is usually hinted at
by ordinary
blood tests and
easily confirmed by measuring the amount of the vitamin in the blood.
In contrast to the infrequency with which B12 deficiency is
proven, vitamin B12 has long been used as a ‘treatment’ for fatigue and as an
energy booster, both in human and in veterinary medicine. It undoubtedly has a
strong placebo effect (the response one gets from an inactive treatment if the
person receiving it believes strongly enough that it works).
Although vitamin B12 is an active substance, once the body’s
stores are topped up any excess is simply excreted in the urine so there is no
logic to using it outside of deficiency states. Vitamin B12 has been used in
CFS/ME but not in trials sufficiently well designed to separate the real from
the placebo effects. Anecdotal evidence suggests it can be helpful in about a
third of patients.
NADH (nicotinamide adenine dinucleotide) is a substance which
facilitates the energy-releasing reactions that occur within cells. In a small
trial of 33 patients with CFS/ME who took an oral supplement of NADH, a small
number had a modest improvement. A larger trial of this treatment is planned.
Carnitine and Co-enzyme Q10 (ubiquinone) are both
‘energy-providing substances’ that can be obtained from health food stores.
There are no good trials of their use in CFS/ME but there is anecdotal support
for their use in general fatigue.
Complementary medicine
To touch upon the use of complementary treatments,
irrespective of the condition for which they are used, is to open up one of the
widest fields of debate in medicine.
There are plenty of contrasting, even opposite, views around
within the public and especially the professional arenas. There are the
devotees of evidence-based medicine who can’t find the studies that show these
therapies work better than placebo.
There are also the many millions of satisfied users of
complementary treatments who rightly have a better opinion of themselves than
as simply gullible consumers or the victims of faddism.
In contrast to the vast resources of the conventional
pharmaceutical industry which spends billions of pounds annually on drug
research the amount of funding that goes into complementary research is tiny.
There is little or no money to be made, in drug industry terms, in finding out
if a particular type of herb is useful in treating CFS/ME because the treatment
could not be patented or commercialised.
Certainly there is a large body of medical literature on
complementary treatments but it will never be comparable, either in quality or
quantity, to ‘conventional’ treatments. For some doctors, and patients, that
means that complementary medicine is a no-go area. For others willing to live
with the fact that life isn’t perfect then there is much to be gained from
them.
Arguments over which treatment is better than any other are
unhelpful because different conditions lend themselves to being treated in
different ways. How to choose a suitable complementary therapy is outside the
remit of this article.
Homeopathy has the advantage of being available within the
NHS, albeit to a limited degree. In a few areas NHS clinics in acupuncture and
hypnotism are also available. Some complementary treatments are however of
dubious value even on the most generous of analysis and many are very
expensive, so at least make sure that you seek an accredited practitioner in
the treatment.
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References
Rutherford D, series editor. NetDoctor: Chronic fatigue
syndrome. London: Hodder & Stoughton; 2003.
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Last updated 02.06.2005
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