rachel.stein

Source: http://freespace.virgin.net/david.axford/meintrop.htm

Basic Introduction to CFS(ME)

Dr. E. M. Goudsmit
Chartered Health Psychologist/Archivist, London.


Chronic fatigue syndrome (CFS) is the term used to describe a
number of disorders characterised by disabling, ongoing fatigue.
Although the nomenclature for these conditions is comparatively
new, the disorders themselves are not. Indeed, references to
illnesses closely resembling CFS have been do***ented in
the British literature since 1750 (Bakheit 1993) . Some cases of
CFS are closely associated with and may represent psychiatric
disorders (David 1991, Hickie et al 1995, Wessely 1994) .
Others have been linked with infections such as glandular
fever and Lyme disease (Bruce-Jones et al 1994, Coyle et al
1994) and exposure to toxins (Behan and Haniffah 1994,
Chester and Levine 1994). However, since the 1980s, much of
the attention has focused on a mysterious illness known as
myalgic encephalomyelitis (ME) or post-viral fatigue syndrome
(PVFS).

In the US, the Holmes et al definition of CFS (1988) tends to
cover many patients with ME; more recent criteria (e.g. Fukuda
et al 1994, Sharpe et al 1991) select a much more
heterogeneous population.


The diagnosis of ME

There are a number of definitions and guidelines which have
been formulated for the diagnosis of ME. For clinical purposes,
some specialists use the definition suggested by Ramsay
(1988) and Dowsett (Dowsett et al 1990 and Dowsett and
Welsby 1992). This recognises both acute onset cases which
follow an infection and the cases which develop more gradually.


The cardinal features of ME as described in Dowsett and
Welsby (1992) and Macintyre (1992) are considered to be:

1.Generalised or localised muscle fatigue following minimal
exertion with prolonged recovery time.
2.Neurological disturbances.
3.Variable involvement of cardiac and other bodily systems.
4.An extended relapsing course with a tendency to chronicity.
5.Marked variability of symptoms in the course of a day.

For research purposes, ME specialists have devised what have
become known as the 'London criteria' (National Task Force
Report 1994). These require the presence of fatiguability
following minor exertion, evidence of central nervous
involvement and the marked fluctuation of symptoms.
Furthermore, the symptoms should have lasted at least six
months and must be ongoing.

The emphasis on both fatiguability and central nervous system
involvement means that the criteria for ME are consistent with
the guidelines for PVFS formulated by Ho-Yen (1993) and the
case definitions of CFS developed by Australian
researchers (Lloyd et al 1990) and Walsh and Cunha (1993).
They are also similar to the definitions of PVFS adopted by
Behan and his colleagues (Behan and Bakheit 1991) and Weir
(1991) .

The criteria for ME differ from the American and Oxford
definitions for CFS in three ways. Firstly, the latter do not require
evidence of central nervous system dysfunction. Secondly, they
do not include any references to the fluctuation of symptoms or
the close links between symptoms and exertion. Thirdly, the
older CDC criteria place a much greater emphasis on
infection-related symptoms such as mild fever, sore throat and
tender glands compared to the definitions of ME (Hyde
et al 1992) .

The view that ME may not be identical to all cases covered by
the term CFS led the National Task Force on CFS, PVFS and
ME, an independent body of experts which was set up to advise
the British Department of Health, to describe the various
disorders as the "chronic fatigue syndromes". They also chose
to distinguish between specific subgroups, for instance, giving
the name CFS(ME) to cases of CFS who also met the criteria
for ME. In line with their approach and similar suggestions by
Wilson et al (1994) and Schluederberg et al (1992), this
classification will also be adopted here to denote cases
diagnosed as either ME or PVFS.


CFS(ME) versus other fatigue states

Since the introduction of the term CFS, many researchers have
expressed concern about the growing emphasis on the symptom
of fatigue (e.g. Hyde et al 1992) . For instance, it has been
pointed out that tiredness is a common complaint among the
general population (Cathebras et al 1992, Popay 1992), and
associated with a variety of disparate causes (Cope et al 1994,
Pawlikowska et al 1994) . Indeed, as recent studies have shown,
most patients who seek help for chronic fatigue do not fulfil the
criteria for CFS(ME) or strictly-defined CFS (1) (Wessely et al
1995, Wilson et al 1994) . For example, in one study of 611
people attending their general practitioners, 70 (11.5%) reported.
experiencing fatigue for three months or more (David et al 1990)
Of these, only one person (1.4%) was thought to have
CFS(ME).

These results are consistent with those of Elnicki et al (1992)
who identified only one case (2%) of CFS among 52 patients
with chronic fatigue. Similarly, a study of 135 patients
complaining of fatigue for one month revealed that only six
(4.4%) met the CDC criteria for CFS (Manu et al 1988) . It is
possible therefore, that factors which are of aetiological and
the****utic significance for most patients presenting with
unexplained fatigue may not be relevant to people with either
CFS or subgroups such as CFS(ME) . Until more is known
about the differences between chronic fatigue and CFS,
generalising findings from one sample to another may lead to an
inaccurate interpretation of the data and possibly to
inappropriate advice and an exacerbation of symptoms (cf.
Wessely et al 1995).

Unfortunately, researchers do not always distinguish between
subgroups of patients with chronic fatigue (e.g. Pawlikowska et
al 1994) . Moreover, where subgroups are identified, it is not
always clear whether the diagnosis was made by clinicians
using accepted definitions. For instance, MacDonald et al
(1993) noted that 4 (23.5%) of their CFS patients thought that
they had CFS(ME) . However, these researchers did not state
how this diagnosis had been made.

A number of features can be used to distinguish CFS(ME) from
other fatigue-related disorders. One is the nature of the fatigue.
For example, Durndell (1989) reported that a group of students
with CFS(ME) were able to differentiate between their fatigue
and the normal tiredness which might follow an activity such as a
sporting event. According to Durndell: "the latter was described
as pulsating, exhilarating and pleasant, whilst the former was
described as overwhelmingly negative, draining, like flu and
being ill".

A second difference between CFS(ME) and other disorders
relates to the marked fluctuations in symptoms and signs (e.g.
Durndell 1989, Patarca et al 1993, Ramsay 1988) . The
presence of the latter can be used to differentiate CFS(ME) from
the condition colloquially referred to as 'tired-all-the-time' or
TATT (Dowsett and Welsby 1991) . A third feature which may
distinguish CFS(ME) from other conditions is the characteristic
link between exertional and fatigue. Research has shown that
this is far less pronounced in psychiatric disorders such as
depression (White et al 1995) . A diagnosis of depression is
further supported by the presence of anhedonia, apathy, reduced
feelings of self-worth, suicidal ideation, delusions and
psychomotor retardation, all of which are less common in
CFS(ME) (Calabrese et al 1992) .

Another disorder which may be confused with CFS is
hyper-ventilation or effort syndrome (Nixon 1993) . However,
while overbreathing has been do***ented in some patients with
CFS, research to date has not found this to be a common
problem in the patient group as a whole (Riley et al 1990, Saisch
et al 1994) .

Since a number of conditions now referred to as CFS are clearly
different from the disorder described in 1988 (cf. Price et al
1992), some American specialists have referred to the more
severe condition as CFS with encephalopathy or chronic
fatigue immune dysfunction syndrome (Bell 1991, Peterson et al
1992, Pross 1992, Suhadolnik et al 1992) .


CFS(ME) and fibromyalgia

CFS(ME) patients may report areas of muscle tenderness
similar to those do***ented in fibromyalgia. However, the latter
more often has a gradual onset, morning stiffness is a more
prominent symptom, fatigue tends to be worse early in the day,
and there are generally fewer signs of ongoing infection
(Calabrese et al 1992, Yunus 1994) . Fibromyalgia is also more
common than CFS, affecting an estimated 2-4% of the
population at large (Wolfe 1993) . While further clarification is
clearly required, the consensus of opinion seems to be that the
two conditions share certain similarities, but that they are not one
and the same (Ho-Yen 1994, Norregaard et al 1993,
Wysenbeek et al 1991) .

The clinical picture of CFS(ME)

The illness seen nowadays tends to start as an unremarkable
viral infection, with myalgia, lymphadenopathy and in some
cases, a gastro-intestinal or respiratory upset (Shepherd 1992) .
However, instead of recovering, patients begin to experience
profound fatigue following activities which were previously
completed without difficulty. Also typical is a prolonged delay in
the restoration of muscle power (Ramsay 1988) .

The fatigue, which some have likened to that reported by people
with multiple sclerosis (Behan and Bakheit 1991), is invariably
accompanied by other complaints. For instance, many patients
report a flu-like malaise, general weakness and neurological
symptoms such as disequilibrium and vertigo (Dowsett et al
1990, Murdoch 1987, Shepherd 1992) .

The involvement of the autonomic nervous system may lead to
frequency of micturition, night sweats, palpitations and
disturbances in thermoregulatory control e.g. feeling weak after a
hot bath (Macintyre 1992, Ramsay 1988, Shepherd 1992) .
Patients may also experience sensory disturbances such as
paraesthesia, tinnitus and hyperacusis as well as visual
abnormalities such as photophobia (Potaznick and Kozol 1992),
sluggish accommodation (Hyde and Jain 1992) and/or
increased sensitivity to certain patterns (Smith 1991) . At the
same time, problems with co-ordination may lead to falls, while
clumsiness can make it harder to complete fine motor tasks.

Neuropsychological symptoms associated with CFS(ME)
include headaches and cognitive problems such as loss of
short-term memory, an inability to concentrate and difficulty in
finding the right word (Fleming 1994) . In addition, many patients
become emotionally labile, and some also begin to experience
panic attacks, depression (Macintyre 1992, Shepherd 1992)
and sleep disorders (Krupp et al 1993, Whelton et al 1992) .

Aside from the fatiguability, the muscle weakness and apparent
central nervous system dysfunction, there may also be symptoms
associated with impaired circulation. This manifests itself in cold
extremities, low temperatures and a sudden facial pallor
(Ramsay 1983). Other symptoms commonly reported by
patients with CFS(ME) include gastro-intestinal disturbances
such as recurring nausea and abdominal pain, and the
development of adverse reactions to alcohol, foods and
chemicals (Hobbs et al 1989, Innes 1970, Smith 1989) .

All these symptoms show a marked diurnal and cyclical
variability in their intensity, and although it is not always possible
to identify a specific cause for the exacerbations, reports
suggest that the condition may worsen as a result of
over-exertion, concurrent infections, changes in the weather, and
in some cases, by 'stress' (Dowsett et al 1990, Komaroff 1994).

Unfortunately, since the adoption of the term CFS, less attention
has been paid to some of the features and symptoms of
CFS(ME), e.g. the fluctuations and the presence of neurological
complaints. For instance, David and Wessely (1993)
summarised the illness as "characterised by a main complaint of
fatigue, both mental and physical, with other somatic symptoms
and mental phenomena like worry and depression present" .
This is consistent with other descriptions of CFS and although it
is recognised that space often prohibits a fuller discussion, the
emphasis on fatigue may have limited many clinicians'
understanding of CFS(ME) . It may also undermine the
diagnostic process, since there is still no laboratory test for
CFS(ME), and physicians have little to guide them except their
knowledge of symptomatology (Holmes et al 1988, Weir, 1991) .

********

1. Strictly-defined CFS refers to cases which fulfil the
Australian criteria, or early versions of the CDC criteria (1988,
1992) .

*********

Copyright Dr. EM. Goudsmit 1996. All rights reserved.
This article may not be reproduced without permission
from the author.

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