Chronic Fatigue Syndrome
Lucinda Bateman MD
The 1988
(CDC or Holmes) CFS Case Definition (or “Working Case Definition of CFS”)
requires that patients meet the Major
Criteria of new onset fatigue
and fatigability that does not
resolve with rest, that causes at least a 50% reduction in activity, for at
least 6
months,
and the exclusion of all other
illnesses that can cause fatigue, including existing psychiatric illness, and Minor
Criteria of >6
month duration, including at least 6 of 8 symptoms
(fever,
sore throat, painful lymph nodes, general weakness, prolonged fatigue after
exercise, headaches, arthralgia, sleep disturbance, neuropsychological
complaints, and sudden onset of symptoms complex)
and 2
signs
(low grade fever. non~exudative pharyngitis, and palpable or tender
lymph nodes).
The 1994
"Revised Case Definition of CFS" (Annals of Internal Medicine
December 1994, Fukuda)
is reached after a process of excluding other
illnesses and is defined as: clinically evaluated, unexplained persistent or
relapsing chronic fatigue of > 6 month duration, not otherwise explained
by another known medical or psychiatric condition (, of new or definite onset,
not the result of ongoing exertion,
not
substantially
alleviated by rest, and that results in substantial
reduction
in previous levels of
function; plus concurrent presence of (at least 4): impairment in short term
memory or concentration, muscle pain, joint pain, headaches of a new pattern) or
severity,
unrefreshing
sleep,
sore
throat, tender cervical or axillary lymph nodes, and
post
exertional
malaise. Specific exclusions include: an
ongoing
medical illness that can obviously cause such fatigue,
psychiatric illness psychotic features, dementia, anorexia or bulimia, alcohol
or other substance abuse and obesity defined as a Body Mass Index (BMI) >45
Neither
Case Definition was intended to exclude patients from the diagnosis, but
rather to help identify and treat underlying problems, and to define a better,
more homogeneous, "CFS" group for research purposes. The larger
population of patients with chronic fatigue, exertion intolerance, ill defined
pain, insomnia, cognitive dysfunction and other symptoms probably has a number
of underlying problems that include atypical presentation of known diseases,
combined processes, psychological factors, and disease processes we as yet
poorly understand.
Mounting research in the
last 10 years has clearly shown that in spite of their weaknesses, the 1988
and 1994 Case Definitions successfully separate a group of afflicted and often
disabled patients who do not simply have depression, poor motivation or any
other readily identifiable problem. These patients deserve support and medical
attention both clinically and on a research basis until more data is
forthcoming. Most likely, the CFS Case
Definitions encompass a group made of up more than one cause and combination of
causes.
________________________________________________________________________
The following discussion is based
on published CFS research combined with my own experience and studies of CFS,
and should be considered a working hypothesis:
CFS
tends to
occur in a "genetically predisposed' individual, who is typically
"run down" by
chronic
or severe physical and/or emotional stress, and usually starts with a 'flu
syndrome" that leaves
chronic symptoms and fatigue rather than resolving in
a normal fashion.
The exact cause of CFS is
unknown, No single infection has been proven a primary cause of
CFS,
although many pathogens are under investigation as possible primary or
secondary co-factors. Research suggests that patients with CFS have mildly
suppressed Natural Killer cell activity and cell mediated immunity (probably
abnormal CD4 activation of CD8 viral killing), with a shift toward B-cell
mediated immunity. In the later stages of illness patients have more B-cell
derived illness such as
"allergy" symptoms, unregulated antibody
systems (and thyroid and antinuclear antibodies), and pro-inflammatory
cytokine release. Flow cytometry studies of lymph node biopsy show chronically
activated T-cells (compared to peripheral blood) consistent with this
chronically up-regulated state. It is not clear if
recurrent
or latent virus(s) are currently
present and driving the system,
or it is chronically “immune”
driven
Many patients have significant
autonomic nervous system dysfunction manifest by orthostatic intolerance
sweating. Sicca syndrome (dry eyes and mouth) irritable bowel and reflux,
bladder spasm, etc. Neurocognitive and neuropsychological symptoms are often
prominent, and flare as the symptom complex flares. Abnormal sleep patterns
with alpha intrusion abnormal Stage III, IV and REM phases are often
present. In addition Hypothalamic-Pituitary-Adrenal (HPA)
axis
dysfunction has
been
documented as low CRH contisol,
and perhaps a contribution to the marked orthostatic intolerance or
Neurally Mediated Hypotension (NMH)
documented on Tilt Table testing.
Numerous forms of brain
imaging have demonstrated regional flow abnormalities
(SPECT), areas of hypometabolism (PET) and areas of nonspecific demyelination
or infarct (MRI).
In addition these areas of
research genetic
studies
are underway in twins and affected families in
order to
better
understand the pattern of occurrence
Since the cause of
CFS is
still
unknown, the best
general
treatments
at
this point
for the illness complex and associated symptoms are to:
1) Reduce “stress” of all types.
Avoid pushing
into
severe symptoms. Pace
activity.
Prevent flares of fatigue and pain by gaining insight and taking control
of activity level.
2) Treat mood
symptoms whether primary or secondary by any appropriate method, drug or
non-drug.
3) Achieve
restorative sleep patterns as a high priority. Remove all things that aggravate
sleep. Practice good sleep
hygiene. Take medications for sleep if
other interventions fail
4) Eat a
healthy
diet.
Avoid excessive
sugar, caffeine,
alcohol,
etc.
try
not to gain weight while
ill.
5)
Become
generally well conditioned in terms of stretching, strengthening, and aerobic
fitness. But do it carefully and within the limits or the CFS symptoms
Additional recommendations on an
individual basis:
---If primary or secondary viral
or bacterial infection can be identified, it might respond to empiric
treatment. Some CFS patients seem to have fewer community acquired viral
infections when taking gamma shots especially in the early stages of
CFS, but this has not been studied as an intervention.
---If orthostatic intolerance
is a prominent symptom it usually responds to standard interventions such as
oral fluids (2 liters of water daily) sodium (2-4 gms per day) and electrolyte
supplementation and sometimes a trial of ProAmatine
2.5-15
mg 3 -4
times a day while up and active. (I.e. not while sleeping or resting)
---Stimulants are
occasionally helpful, but should be used cautiously because of impact on sleep,
anxiety, and the tendency to over exert
instead of pace appropriately.
---Antidepressant and
anti-anxiety medications can be helpful for
some parts of the syndrome besides mood.
EVERY
prominent or focal symptom should be investigated