Website: http://worcsmegroup.weebly.com
Chairman - Ian Logan (01886 888419)
Vice Chairman - Warwick Davis (01384 892442)
Worcestershire
M.E. Support Group
Criteria - Canadian Guidelines (contrasted to Oxford and Fukuda)
The complete 109-page article 'Myalgic Encephalomyelitis/CFS: Clinical Working Case Definition,
Diagnostic and Treatment Protocols', Journal of CFS, Vol. 11 (1) 2003, pp. 7-116, is available at
www.mefmaction.net/documents/journal.pdf
This summary is paraphrased from Dr. Kenny van DeMeirleir's book 'CFS: A Biological Approach',
Feb. 2002, p.275. The Canadian Consensus Panel clinical case definition more accurately
represents the experience and manifestations of the disease than other current case definitions
ie Oxford or Fukuda.
1. Post-exertional Malaise and fatigue: there is a loss of physical and mental stamina, rapid
muscular and cognitive fatigability, post-exertional fatigue, malaise and/or pain, and a tendency
for other symptoms to worsen. A pathalogically slow recovery period (it takes more than 24
hours to recover). Symptoms exacerbated by stress of any kind. Patient must have a marked
degree of new onset, unexplained, persistent, or recurrent physical and mental fatigue that
substantially reduces activity level. [ME Society of America Editor's note: The ME Society
prefers to use 'delayed recovery of muscle function', weakness, and faintness rather than
'fatigue'. Further, we disagree that the muscle dysfunction is 'unexplained'] - (see their ME
Definitional Framework and researchers' medical explanations at the same link at top of page).
2. Sleep Disorder: Unrefreshing sleep or poor sleep quality; rhythm disturbance.
3. Pain: Arthralgia and/or myalgia without clinical evidence of inflammatory responses of joint
swelling or redness. Pain can be experienced in the muscles, joints, or neck and is sometimes
migratory in nature. Often, there are significant headaches of new type, pattern and severity.
4. Neurological/Cognitive Manifestations: Two or more of the following difficulties should be
present: confusion, impairment of concentration and short-term memory consolidation,
difficulty with information processing, categorising, and word retrieval, intermittent dyslexia,
perceptual/sensory disturbances, disorientation, and ataxia. There may be overload
phenomena: informational, cognitive and sensory overload (eg photophobia and hypersensitivity
to noise) and/or emotional overload which may lead to relapses and/or anxiety.
5. At least One Symptom Out of Two Of The Following Categories:
a. Autonomic Manifestations: Orthostatic Intolerance eg neurally mediated hypotension (NMH),
postural orthostatic tachycardia syndrome (POTS), delayed postural hypotension, vertigo,
light-headedness, extreme pallor, intestinal or bladder disturbances with or without irritable
bowel syndrome (IBS) or bladder dysfunction, palpitations with or without cardiac arrhythmia,
vasomotor instability, and respiratory irregularities.
b. Neuroendocrine Manifestations: Loss of thermostatic stability, heat/cold intolerance, anorexia
or abnormal appetite, marked weight change, hypoglycemia, loss of adaptability and tolerance
for stress, worsening of symptoms with stress and slow recovery, and emotional lability.
c. Immune manifestations: Tender lymph nodes, sore throat, flu-like symptoms, general malise,
development of new allergies or changes in status of old ones, and hypersensitivity to
medications and/or chemicals.
6. The illness persists for at least 6 months. It usually has an acute onset, but onset also may be
gradual. Preliminary diagnosis may be possible earlier. The disturbances generally from
symptom clusters that are often unique to a particular patient. The manifestations may fluctuate
and change over time. Symptoms exacerbate with exertion or stress.
(Worcestershire M.E. Support Group’s Library)
October 2005
Page 1 of 2
533570515
Issue 1.0
Canadian contrasted to Oxford and Fukuda
In contrast to the Oxford and Fukuda criteria, the Canadian case definition makes it compulsory
that in order to be diagnosed with ME, a patient must become sympomatically ill after exercise
and must also have neurological, neurocognitive, neuroendocrine, dysautonomic, and immune
manifestations. In short, symptoms other than fatigue must be present for a patient to meet the
criteria.
OXFORD CRITERIA (1991)
Chronic Fatigue Syndrome (CFS)
a:- A syndrome characterised by fatigue as the principal symptom
b:- A syndrome of definite onset that is not life long
c:- The fatigue is severe, disabling, and affects physical and mental functioning
d:- The symptom of fatigue should have been present for a minimum of 6 months
during which it was present for more than 50% of the time
e:- Other symptoms may be present, particularly myalgia, mood and sleep disturbance
f:-
Certain patients should be excluded from the definition. They include:
i:- Patients with established medical conditions known to produce chronic fatigue
(eg severe anaemia). Such patients should be excluded whether the medical condition
is diagnosed at presentation or only subsequently. All patients should have a history and
physical examination performed by a competent physician
ii:- Patients with a current diagnosis of schizophrenia, manic depressive illness, substance
abuse, eating disorder or proven organic brain disease. Other psychiatric disorders
(including depressive illness, anxiety disorders and hyperventilation syndrome) are not
necessarily reasons for exclusion.
The Oxford Criteria was set out in the Oxford Guidelines - MC Sharpe et al. A Report - Chronic
Fatigue Syndrome: Guidelines for Research, JRSM Vol.84, Feb. 1991, pp 118-21.
Of the 21 clinical and scientific researchers who wrote the Oxford Guidelines, eight were in
psychiatry or psychology, another six were research scientists, non-psychiatric clinicians were few
(see BM Hyde, The Clinical and Scientific Basis of ME/CFS, 1992, 12). Notable exclusions were
DS Bell, EG Dowsett, BM Hyde, AM Ramsay and JS Richardson, experts on ME and its
epidemiology.
The Royal Colleges Report on CFS 1996 used the Oxford Criteria and claimed up to 1.4 million
people in the UK had CFS. Estimates of ME incidence are much lower.
The Fukuda CFS Definition can be found in the National Task Force Report on CFS/ME 1998 p.59.
The Oxford and Fukuda Criteria are too inclusive. A number of different types of illness including
ME are being lumped together under the single banner 'CFS'. In the words of Dr Dowsett 'CFS' is
a 'facile euphemism for ME... which enmeshes this serious and potentially life long neurological
illness in a web of trivial fatiguing sub entities... '
(Worcestershire M.E. Support Group’s Library) 533570515
October 2005
Page 2 of 2
Issue 1.0