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New Canadian CFS Guide Stresses
Options for Clinicians
A new clinical case definition for chronic fatigue syndrome
(CFS) could speed patient diagnosis and help establish the illness as a distinct
medical entity, according to the document’s authors.
The expert consensus document was created under the auspices
Canada , the
Canadian national health ministry. The 11 co-authors wrote the guidelines after
soliciting advice and guidance from experts and patients across the world. The
author list includes noted CFS researchers and practitioners such as Daniel L.
Peterson, MD; Nancy Klimas, MD; Kenny De Meirleir, MD, PhD; and A.
Martin Lerner, MD.
The new document is titled, “Myalgic Encephalomyelitis/Chronic
Fatigue Syndrome: Clinical Working Case Definition, Diagnostic and Treatment
Protocols.” It is designed for use by primary care physicians, nurses,
therapists and others who diagnose and treat patients with CFS. CFS is also
known as Myalgic Encephalomyelitis, or ME.
Currently, the most widely accepted definition of CFS is the
1994 International Research Case Definition, also known as the Fukuda Criteria
(see back page).
It was intended for use by researchers to standardize study
populations and protocols, but also is used by clinicians to diagnose CFS in
patients. The Canadian document seeks to replace the Fukuda standards in
The Canadian panel’s clinical definition reprioritizes many of
the symptoms in the 1994 case definition. According to the new definition,
patients must meet each of these four criteria:
Fatigue. Must have a “significant degree” of new
onset, and be unexplained, persistent, or recurrent physical or mental fatigue
that substantially reduces activity level.
Post-Exertional Malaise and/or Fatigue. Patients must
show “inappropriate” loss of physical and mental stamina, among other factors.
There also must be a “pathologically slow” recovery period, usually lasting at
least 24 hours.
Sleep Dysfunction. Patients must exhibit unrefreshing
sleep, or have disturbance in either sleep quantity or rhythm.
Pain. There must be a significant degree of myalgia.
It can be in muscles and/or joints, and may be accompanied by headaches of a
new type, pattern or severity.
In addition, patients must have two or more
“neurological/cognitive manifestations,” including confusion, impairment to
concentration and short-term memory, disorientation, perceptual and sensory
disturbances and other symptoms.
Finally, the patient must exhibit symptoms from two of the
following three categories:
Autonomic. Includes, among other conditions,
orthostatic intolerance, postural orthostatic tachycardia syndrome (POTS),
extreme pallor, nausea and irritable bowel syndrome.
Neuroendocrine. Includes loss of thermostatic
stability, sweating, marked weight change, loss of adaptability and worsening
of symptoms with stress.
Immune. Includes tender lymph nodes, recurrent sore
throats and/or flu symptoms, and sensitivities to foods, medication or
All of these symptoms appear in the 1994 case definition. But
in that definition, fatigue is the only main symptom, and must be accompanied by
four or more of a group that includes the other categories listed above. The
secondary symptoms are not listed under headings such as “autonomic” or “immune”
in the 1994 definition.
In both definitions, fatigue must persist for at least six
months before a diagnosis of CFS can be considered.
The study’s lead author says the new definition will save time
and suffering in the patient population. “The clinical definition will enable
clinicians to make an early diagnosis which may assist in lessening the impact
of ME/CFS in some patients,” said Bruce M. Carruthers, MD. “It will reduce the
expensive problem of patients being sent to many specialists before being
diagnosed and will allow patients to receive appropriate treatments in a timely
Emphasis on treatment
The main body of the new document deals with treatment
protocols. The authors stress that patient support and well-being are the “top
priorities” during treatment, and also call for ample patient education,
individualized treatment plans and patient participation.
“The goal of a management/treatment program is to empower the
patient by encouraging them to trust their own experiences, to enhance the
patient’s awareness of the activities and environments in which they can cope
without exacerbating symptoms and pace themselves accordingly,” the document
says. “The program should aim at optimizing the patient’s ability to maintain
function in everyday activities, being as active as possible within their
boundaries, and then gently extending those boundaries.”
The guidelines also stress the importance of dietary, sleep
and movement/ergonomic habits. In addition, the authors include an extensive
drug protocol for dealing with various symptoms — including sleep disturbance,
pain, fatigue, cognitive dysfunction, psychiatric co-morbidities such as
depression and anxiety, and immune dysfunction.
The Canadian clinical case definition is the third created in
the past year. Other versions were written under the auspices of the British and
Australian governments. The British definition met with strong resistance from
patient advocates after its release. They argued that the document
over-emphasized psychological aspects of CFS/ME and treatments such as graded
exercise therapy and cognitive behavioral therapy (CBT).
The Canadian version lists these therapies, but also mentions
their shortcomings. While CBT can offer coping mechanisms to improve quality of
life for CFS patients, claims that it could be potentially curative are
“objectionable” and “far from being confirmed,” the authors write.
Klimas says she is pleased with both the way the guidelines
were created and the information they contain. “The process used to write the
clinical definition was truly collaborative, involving representatives of the
research community, the medical profession, and patient advocates,” she says. “I
believe that it will be very useful in educating clinicians about the
pathogenesis of CFS, thanks to the inclusion of sections on autonomic,
neuroendocrine and immune-related symptoms. It should also help to validate
patients’ experience and the serious impact CFS has on their lives.”
While intended mainly as a guide for health care
practitioners, the Canadian document also may have long-term ramifications for
the research community. The revised definition criteria tend to select a
slightly different patient spectrum than the one created by the 1994 case
Leonard Jason, PhD, has examined the new
criteria and made some preliminary comparisons. In general, Jason says, the
Canadian document selected patients with less psychiatric co-morbidity, more
physical functional impairment and more fatigue/weakness, neuropsychiatric and
neurologic symptoms than those identified by either the 1994 case definition or
the earlier 1988 (Holmes) criteria.
Jason says the Canadian clinical criteria “appear to select a
more symptomatic group of individuals than the CFS criteria, and these
individuals do demonstrate less cur-rent and lifetime psychiatric impairment
than those selected according to the CFS criteria.”
The three patient groups showed no differences in
sociodemographic levels, according to Jason’s research, which was presented to
the Dutch ME Foundation in April.
Both the 1994 and Canadian definitions would be improved if
more attention was devoted to developing operationally explicit, objective
criteria and standardized interviews, Jason says.
Giuliucci is editor of The
CFS Research Review.
Carruthers B et al. “Myalgic Encephalomyelitis/Chronic
Fatigue Syndrome: Clinical Working Case Definition, Diagnostic and Treatment
Protocols.” J Chronic Fatigue Syndrome.