A Hummingbirds' Guide to M.E.
Information on the neurological disease Myalgic Encephalomyelitis
M.E. (and ICD-CFS) Articles, Research and Books
Research topics: General Articles and Research Overviews, Immune System Research, Viral Research, Cardiac Research, Exercise Research, Muscle Research, Metabolic Research, Neurological and Cognitive Research, Genetic Research, Neuroendocrine Research, and Miscellaneous Research.
Article topics: The Definitions of M.E., On 'fatigue', CBT, GET and the unscientific 'behavioural' paradigm of M.E., On 'stress', M.E. Outbreaks, On the Name Myalgic Encephalomyelitis, M.E. and Other Illnesses, Children with M.E., The Severity of M.E., M.E. Fatalities, Activism Articles, Articles sorted by Author, Articles sorted by Country and Historical, Political and Medical Overviews.
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Putting Research and Articles into ContextOn this page: The Definitions of M.E (and CFS) page 1 of 1
Articles of increased importance are highlighted in green *O*
The Definitions of M.E. and CFS
Preface
Since the Nightingale Research Foundation's publication in 1992 of its textbook, The Clinical and Scientific Basis of Myalgic Encephalomyelitis / Chronic Fatigue Syndrome, there has been a tendency by some individuals and organizations to assume that M.E. and CFS are the same illness. Over the course of two International Association of Chronic Fatigue Syndrome (IACFS, formerly the American Association of CFS) conferences, there have been suggestions that the name CFS be changed to M.E., while retaining the CFS definitions as a basis for such change. This does not seem to me to be a useful initiative: it would simply add credence to the mistaken assumption that M.E. and CFS represent the same disease processes. They do not.
M.E. is a clearly defined disease process. CFS by definition has always been a syndrome
At one of the meetings held to determine the 1994 U.S. Centers for Disease Control and Prevention (CDC) definition of CFS, in response to my question from the floor, Dr. Keiji Fukuda stated that numerous M.E. epidemics he cited the Los Angeles County Hospital epidemic of 1934, the Akureyri outbreak of 1947-48 and the 1955-58 Royal Free Hospitals epidemics-- were definitely not CFS epidemics. Dr. Fukuda was correct.
The Psychiatric Label
Unfortunately many physicians and some senior persons in governments, including Great Britain, Norway and to a lesser degree the USA and Canada treat CFS as a psychiatric illness. This view has been arrived by some physician's readings of the CFS definitions from CDC. Indeed, despite clear signals in the 1994 CDC definition that CFS is not a psychiatric disease, each of the CDC definitions and their addenda referring to CFS remain open to interpretation as a psychiatric rather than a physical illness. This is not a view to which I subscribe. It is the CFS definitions themselves that give rise to this inaccuracy. Consider the following:
(a) What other physical disease definitions essentially state that if you discover the patient has any physical injury or disease, then the patient does not have the illness CFS? In other words if you have CFS then it does not result in or cause any major illness. What else could CFS then be but any number of various psychiatric, social, hysterical or mendacious phenomena?
(b) The various CDC administrations dealing with the subject have clearly stated that CFS is a physical, not a psychiatric disease. However, is there any other definition of any physical disease that is not provable by scientific and clinical tests? Only psychiatric diseases are not clearly verifiable by physical and technological tests.
(c) What other physical disease definition requires a six month waiting period before the illness can be diagnosed? Any physician knows that to treat a disease adequately you have to be able to define the disease at its onset and treat it immediately in order to prevent chronic complications from arising. There are simply no other disease definitions that have ever been assembled similar to the CFS definitions.
I believe it essential to define clearly Myalgic Encephalomyelitis. That is what the Nightingale definition of M.E. sets out to do
A simplified definition of Myalgic Encephalomyelitis
Myalgic Encephalomyelitis is:
1 A variable and biphasic acute onset disease
2 Primary Infection Phase: The first phase is an epidemic or endemic infectious disease generally with an incubation period of 4 to 7 days, where in most, but not all cases, an infection is evident.
3 Chronic Phase: The second and chronic phase follows closely on the first phase, usually within two to seven days, and is characterized by a measurable diffuse change in the function of the CNS. This is the persisting disease that most characterizes M.E. and is demonstrated by the following:
4 Testable Brain Changes: This second phase becomes chronic and is characterized by various measurable and clinical dysfunctions of the cortical or cortical and sub cortical brain. If the patient's illness is not persistently measurable using SPECT, PET or QEEG and/or Neuropsychological changes then it is not M.E. These changes can be roughly characterized as to severity:
1. Type 1: where one side of the cortex is involved. These patients have the best chance of spontaneous recovery.
2. Type 2: where both sides of the cortex are involved: These patients have the least chance of spontaneous recovery.
3. Type 3: where both sides of the cortex, and either one or all of the posterior chamber organs, the Pons and Cerebellum, the sub cortical and brain stem structures are involved. Type 3 are the most severely affected patients and the most likely to be progressive or see little or no improvement with time.
5 Pain Syndromes: The pain syndromes associated with the acute and chronic phases of M.E. may include (a) severe headaches of a type never previously experienced, (b) often associated with neck rigidity and occipital pain, (c) retro-orbital eye pain, (d) migratory muscle and arthralgia pain, (e) cutaneous hypersensitivity and (f) fibromyalgia type pain. These pain syndromes tend to decrease over time.
6 Neuropsychological Changes: There are neuropsychological changes that are measurable and demonstrate short-term memory loss, cognitive dysfunctions, increased irritability, confusion, and perceptual difficulties. There is usually rapid decrease in these functions after any physical or mental activity. This feature may improve over a period of years in patients with adequate financial and social support.
7 Major Sleep Dysfunction: including all forms of sleep dysfunction and day time alertness and sleep reversals.
8 Muscle Dysfunction: This feature may be due to vascular dysfunction or peripheral nervous or spinal dysfunction and includes both pain and rapid loss of strength of muscle function after moderate physical or mental activity.
9 Vascular Dysfunction: This is the most obvious dysfunction when looked for and probably is the cause behind a significant number of the above complaints. Vascular change is most evident in patients with:
a. POTS: severe postural hypotension.
b. Cardiac irregularity: on minor positional changes or after minor physical activity, including inability for the heart to increase or decrease in speed and pump volume in response to increase or decrease in physical activity.
c. Raynaud's Disease: vasoconstriction, blanching, coldness and pain of extremities. This is in part the cause for temperature dysfunctions seen in M.E.
d. Bowel Dysfunction: vascular dysfunction may be the single most causal basis behind bowel dysfunction when it occurs
10 Endocrine Dysfunction: This feature is common and tends to be a late appearance and is most obvious in the:
a. Pituitary-thyroid axis: This is common. Changes in serum TSH, FTI, FT4, Microsomal Ab., PTH, Calcium and phosphorus rarely occur until one or more years after illness onset and usually only after several years. This can be followed by ultrasound of the thyroid gland where a steady shrinking of the thyroid gland occurs with or without the development of non-serum positive Hashimoto's thyroiditis (a seeming contradiction of terms) and a significant increase in thyroid malignancy. Serum positive changes occur only after years.
b. Pituitary-adrenal axis changes: this finding is infrequent.
c. Pituitary-ovarian axis changes:
d. Pituitary-Bladder dysfunction: occurs frequently in the early disease in some people. It is unknown if the cause is due to this link.
*O*O* A New and Simple Definition of Myalgic Encephalomyelitis and a New Simple Definition of Chronic Fatigue Syndrome & A Brief History of Myalgic Encephalomyelitis & An Irreverent History of Chronic Fatigue Syndrome by Dr Byron Hyde MD (an extract) 2006
‘Do not for one minute believe that CFS is simply another name for Myalgic Encephalomyelitis (M.E.). It is not. Though CFS is based upon a typical M.E. epidemic, in my opinion it has always been a confused and distorted view of reality. The invention of Chronic Fatigue Syndrome has to be one of the most curious cases of inventive American scientific imperialism that one could imagine. It is my opinion that the CDC 1988 definition of CFS describes a non-existing chimera based upon inexperienced individuals who lack any historical knowledge of this disease process. The CDC definition is not a disease process.’
*HIGHLY RECOMMENDED*
*O* ME and CFS, The Definitions from the Committee for Justice and Recognition of Myalgic Encephalomyelitis.
[Contains details of many of the different CFS and M.E. definitions]
"The Committee feels there has been a particular effort to confuse the public about Myalgic Encephalomyelitis. Most of this effort has been rooted in the promotion of the term Chronic Fatigue Syndrome to describe this disease, which has been spreading in epidemic fashion worldwide during the last twenty years. Of particular note is the outright effort undertaken since 1988 by the American CDC to eliminate the name and definition of M.E. and replace it with CFS. [But] no CFS definition defines a neurological disease. All definitions which wear the 'f' word (ie. fatigue) in their name are not ME nor neurological. They are definitions of fatigue conditions. And when these definitions were written it was not neurological ME which they were attempting to define."
Testing for Myalgic Encephalomyelitis by Jodi Bassett
An overview of some of the series of tests which can be done to help confirm a suspected M.E. diagnosis (plus further information on many other aspects of diagnosis including discussion on the benefits and limitations of the Canadian criteria).
The misdiagnosis of CFS by Jodi Bassett
None of the definitions of CFS defines M.E., so what do they define? What does a diagnosis of CFS actually mean?
What is Myalgic Encephalomyelitis? by Jodi Bassett
A historical, political and medical overview of M.E.
Smoke and Mirrors by Jodi Bassett
This paper looks at the lack of evidence (and financial and political motivations) behind the 'behavioural' model of M.E. and outlines a strategy for the resolution of the confusion caused by the 'CFS' disease category.
Myalgic Encephalomyelitis is not fatigue, or 'CFS' by Jodi Bassett
*O* Canadian Expert Consensus Panel Clinical Case Definition for ME/CFS
Read more about the benefits and the limitations of the Canadian Guidelines at: Canadian Guidelines Review
*O* Comparing the Canadian Clinical Definition and the Fukuda Criteria For Chronic Fatigue Syndrome by Dr. Leonard Jason
"None of the current CFS case definitions have been empirically derived or prospectively contrasted with one another. Studies examining sources of diagnostic unreliability have shown that subject, occasion, and information variance account for only a small portion of diagnostic reliability. However, criterion variance, differences in the formal inclusion and exclusion criteria used by clinicians to classify patients' data into diagnostic categories, accounts for the largest proportion of diagnostic unreliability. Case definitions would be improved if more attention was devoted to developing operationally explicit, objective criteria and standardized interviews."
Authors: Kennedy G, Abbot NC, Spence V, Underwood C and Belch JJF
Conclusions: Differences in simple, easily performed clinical outcome measurements can be observed between groups of patients, all of whom fulfill the CDC-1994 criteria for CFS. It is likely that their response to treatment may also vary. The specificity of the CFS case definition should be improved to define more homogeneous groups of patients for the purposes of treatment and research.
*O* Maryann Spurgin, Ph.D.,reviews the 2003 ME/CFS clinical case definition
"In 1994, a group of government propagandists and psychiatrists on the take from insurance companies created one of the most damaging documents in the fifty-year history of ME/CFS: the 1994 Centers for Disease Control Case Definition. Hillary Johnson was one of the first harshly to criticize the document in her book Osler’s Web, stating that the criteria were too broad and failed to describe the disease with which she and so many of us had been stricken, the disease that caused post-exertional sickness and neurological problems. Instead, it selected heterogeneous fatigue states under the CFS umbrella. This lead to inconsistent research results and inappropriate treatment protocols like cognitive behavioral therapy (CBT) and graded exercise therapy (GET), which caused many patients to become worse."
*O* MYALGIC ENCEPHALOMYELITIS : A Baffling Syndrome With a Tragic Aftermath. By A. Melvin Ramsay M.D., Hon Consultant Physician, Infectious Diseases Dept, Royal Free Hospital. [Published 1986]
The syndrome which is currently known as Myalgic Encephalomyelitis in the UK... leaves a chronic aftermath of debility in a large number of cases. The degree of physical incapacity varies greatly, but the dominant clinical feature of profound fatigue is directly related to the length of time the patient persists in physical effort after its onset; put in another way, those patients who are given a period of enforced rest from the onset have the best prognosis.
*O* Myalgic Encephalomyelitis (ME): a review with emphasis on key findings in biomedical research by Professor Hooper 2006, printed in the BMJ
‘Undoubtedly the perverse use of chronic fatigue syndrome, to impose a psychiatric definition for ME/CFS by allying it to fatigue syndromes, has delayed research, the discovery of effective treatment(s), and care and support for those suffering from this illness
I would propose that the use of CFS should now be abandoned and that, following the Minister of Health’s assurances, the WHO definition is now accepted and used in all official documentations. The excellent work on the biological aspects of ME, already carried out by several leading research groups, now requires significant funding.’
*O* Are Myalgic Encephalomyelitis and Chronic Fatigue Syndrome Synonymous Terms?
Paper Presented by Byron Marshall Hyde M.D. – Nightingale Research Foundation. New South Wales, February 1998
At the 1998 M.E./CFS conference in Australia, both Myalgic Encephalomyelitis and Chronic Fatigue Syndrome were used to describe a chronic illness. This paper is a discussion on the similarities and differences in these two terms that may lead to scientific difficulties. The author suggests that the definitional criteria and epidemic history of Myalgic Encephalomyelitis (M.E.) and the inclusion criteria are significantly different from the CDC definitions and history. The three typical phases of M.E. are discussed. A brief review of some of the known deaths in phase 2 of M.E. are also mentioned.
Improving the diagnostic criteria and procedures for chronic fatigue syndrome Biological Psychology, Volume 68, Issue 2, Feb 2005, Pp 87-106 Caroline King [a] and Leonard A. Jason [b] [a] 4 June 2004.
Abstract Since the publication of the case definition for chronic fatigue syndrome (CFS) in 1988 the diagnostic criteria have been revised twice in the U.S. None of the case definitions were derived empirically. As a result, there is concern regarding the sensitivity, specificity, and reliability of the criteria. The goal of the present study was to identify methods for improving the diagnostic criteria for CFS. Three groups of 15 participants each were recruited: participants with (1) CFS, (2) major depressive disorder (MDD), and (3) healthy controls. Using statistical procedures, three methods for improving the diagnostic criteria were explored: identification of new diagnostic symptoms, the use of severity ratings for symptomatology, and the identification of standardized measures that differentiate cases of CFS from other conditions. Results of the present study suggest that these three methods hold promise for improving the sensitivity, specificity, and reliability of the diagnostic criteria for CFS.
Usefulness of the Fukuda and Holmes definition in the diagnosis of CFS P De Becker [1], J Nijs [1], N McGregor [2], K De Meirleir [1] Dept. of Human Physiology, Vrije Universiteit Brussel, Belgium Collaborative Pain Research Unit Department of Biological Sciences Faculty of Science University of Newcastle Callaghan, New South Wales Australia
The Holmes and Fukuda criteria are widely used criteria all over the world, yet a specific European study regarding CFS patient symptomatology has not been conducted so far. This study was performed in an outpatient tertiary care setting fatigue clinic in Brussels. 2073 consecutive patients with major complaints of prolonged fatigue participated in the study. Multi-variate analyses were performed to assess the symptom presentation within a fatigued population and the differences between the Fukuda and Holmes definitions compared with an excluded chronic fatigued group in a large cohort of fatigued patients. Of the 2073 patients complaining of chronic fatigue, 1578 CFS patients fulfilling the Fukuda criteria (100% of CFS group) and 951 (60.3% of the CFS group) fulfilled the Holmes criteria. Discriminantfunction analysis revealed that the Fukuda and Holmes definitions can be differentiated by symptom severity and prevalence. The Holmes definition was more strongly associated than the Fukuda definition with the symptoms that differentiated the CFS patients from the patients that did not comply with the CFS definitions. The inclusion of ten additional symptoms was found to improve the sensitivity/ specificity and accuracy for selection of CFS patients. The CFS patients fulfilling the Holmes criteria have an increased symptom prevalence and severity of many of the symptoms that determine the difference between CFS and CF patients. Patients fulfilling the Fukuda criteria were less severely affected patients which leads to an increase in clinical heterogeneity. We can conclude that the use of the Holmes criteria defining symptoms of fatigue, swollen/tender lymph nodes, sore throat, muscle weakness, recurrent flu-like symptoms, postexertional fatgigue, myalgia, memory disturbance, nonrestorative sleep with addition of certain symptoms (hot flushes instead of low-grade fever, attention deficit, paralysis, new sensitivities to food/drugs, difficulties with words, urinary frequency, cold extremities, photophobia, muscle fasciculations, lightheadedness, exertional dyspnea and gastrointestinal distrurbance) to the Holmes definition and removal of others (arthralgia and low-grade fever) would strengthen the ability to select CFS patients, also the incorporation of a severity index would be beneficial for subcategorization of patients.
Idiopathic chronic fatigue and chronic fatigue syndrome: a comparison of two case-definitions. Arpino C, Carrieri MP, Valesini G, Pizzigallo E, Rovere P, Tirelli U, Conti F, Dialmi P, Barberio A, Rusconi N, Bosco O, Lazzarin A, Saracco A, Moro ML, Vlahov D Laboratorio di Epidemiologia e Biostatistica, Istituto Superiore di Sanita, Rome, Italy. [Medline record in process]
The aim of the study was to compare the signs and symptoms of individuals meeting two different definitions of chronic fatigue syndrome (CFS). Ninety-four patients fitting the eligibility criteria for idiopathic fatigue were enrolled into the study. Of the 94 patients, 48 met the 1988 definition of CFS, 20 the 1994 (but not the 1988) definition of CFS, and 26 met neither definition. The 1994 defined cases were more likely than 1988 defined cases, and non-syndromal individuals to be male, married, and high school educated. The 1994 cases were less likely than 1988 cases to present acute onset, self reported sore throat, mild fever lymphadenopathy, pharingitis. In conclusion, the 1994 criteria increased the number of patients classified as CFS; however, those who fit only the 1994 criteria were less likely to have an acute symptomatic onset and signs and symptoms suggestive of an infectious process.
Do the 1988 and 1994 CFS case definitions identify the same illness complex? Lana A. Tierskv, Stacy Weisberg, John DeLuca, and Benjamin H. Natelson
Objective: The decision to modify the original CFS case definition was based more on a perceived need to do so than on empirical data to support the proposition that the 1988 CFS case definition did not identify a distinct group of cases. If it is true that the 1988 criteria do not delineate a distinct group of cases, patients fulfilling these criteria should have the same symptom complexes as those fulfilling the relaxed 1994 case definition. Conversely, if patients fulfilling the 1988 case definition are a distinct group, their symptom pattern should differ from the profile of individuals fulfilling the 1994 CFS case definition. One purpose of this study was to evaluate these possibilities by comparing the symptom presentation of subjects diagnosed according to the 1988 CFS diagnostic criteria to the symptom complexes of subjects diagnosed according to the 1994 CFS diagnostic criteria. Differences in activity reduction and symptom onset were also investigated. Methods: Sixty-two subjects completed a questionnaire that obtained information pertaining to CFS symptomatology as well as illness course. The data collection format of the list allowed subjects to respond if a CFS symptom was present as well as at what severity the symptom was experienced. Based on responses to the questionnaire CFS subjects were divided into two groups:
1) Subjects meeting the 1988 criteria for CFS, and
2) Subjects meeting the 1994 criteria.
Patients meeting the 1988 criteria also all met the 1994 criteria; however none of the patients meeting the 1994 criteria also met the 1988 standards. Thus, we were able to delineate two groups. Results: When subjects who met the 1988 case criteria (n=45) were compared to those who met only the 1994 criteria (n=17), subjects in the 1988 group were found to suffer from a more severe form of the illness. Specifically, subjects in the 1988 group demonstrated more severe symptoms as well as a greater reduction in activity. The latter group also more frequently reported infectious-type symptoms as well as a sudden illness onset. Conclusions: The 1988 and 1994 CFS case definition criteria appear to identify distinct patient groups. Given that the subjects in the 1988 group more frequently endorsed infectious symptoms as well as more frequently reported a sudden flu-like illness onset, an infectious etiology for this group is hypothesized.
Heterogeneity of symptom, onset and biochemical profiles in "defined" CFS patients McGregor NR¹*, Hoskin L², Dunstan RH¹, Clifton Bligh P², Butt HL¹, Fulcher G², Roberts TK¹. Dunsmore J², Zerbes M¹, Klineberg IJ*
Objective: To assess the symptom, biochemical and onset data of patients who comply with the CFS definitions to assess whether they are either homogeneous or heterogeneous. The CFS definition requires the exclusion of other known fatigue-related diseases and compliance with a primarily host-response associated symptom constellation.1,2 The patient set derived by this process is heterogeneous in their psychological presentation, and no single ætiological agent or event has been found using this definition. Methods: Multiple regression analysis and clustering techniques were applied to several CFS study data sets to detect either homogeneity or heterogeneity of the patients symptoms, onset events, urinary amino and organic acid, and serum lipid profiles. Results: CFS patients divided on the basis of host responses, infectious responses, sudden or gradual onset or type of onset, had different symptom and biochemical constellations. The disturbances of urinary amino and organic acid excretion could distinguish CFS patients from controls, but the events associated with fatigue or muscle pain, common to all CFS patients, were not selective for defined CFS. Common fatigue-associated host response changes could not be specifically associated with any onset event or psychological response. However alterations in the excretion of various metabolites could be associated with different onset, symptom and psychological response patterns. In a similar manner, the plasma fatty acids profile could differentiate defined CFS patients from control subjects but the differentiating patterns did not occur in all defined CFS patients. The lipid profiles associated with current viral infections, such as EBV, or post-EBV infection were not distinguishing factors for defined CFS. The major lipid changes distinguishing CFS patients from controls appear to be of genetic or acquired origin. Multiple regression and clustering techniques revealed 5 basic types of CFS lipid profiles, whilst the control group had a high degree of homogeneity. These CFS lipid changes are associated with known lipid disorders and provided evidence of heterogeneity. Conclusion: The current CFS definitions either lack standardization and/or the CFS exclusion criteria are insufficient to determine all additional excludable fatigue disorders. The capacity to group currently defined CFS patients into subsets using objectively derived measurements, many of which may indicate known disease states, represents a major advance in CFS research.
A definition-based analysis of symptoms in a large cohort of patients with chronic fatigue syndrome. De Becker P, McGregor N, De Meirleir K.VUB, Vakgroep Interne Geneeskunde, KRO gebouw niv.-1, Laarbeeklaan 101, 1090 Brussels, Belgium. pdbeck@minf.vub.ac.be
OBJECTIVE: The Holmes and Fukuda criteria are widely used criteria all over the world, yet a specific European study regarding chronic fatigue syndrome (CFS) patient symptomatology has not been conducted so far. This study was performed to answer the need to assess the homogeneity of a large CFS population in relationship to the Fukuda or Holmes definitions and to assess the importance of a symptom severity scale. DESIGN: Multivariate analyses were performed to assess the symptom presentation within a fatigued population and the differences between the Fukuda and Holmes definitions compared with an excluded chronic fatigued group in a large cohort of fatigued patients. SETTING: An outpatient tertiary care setting fatigue clinic in Brussels. MAIN OUTCOME MEASURES: Prevalence and severity of symptoms and signs in a CFS population and in a chronic fatigued population. SUBJECTS AND METHODS: A total of 2073 consecutive patients with major complaints of prolonged fatigue participated in this study. Multivariate analyses were performed to assess the symptom presentation and severity and the differences between the Fukuda and Holmes definitions. RESULTS: Of the 2073 patients complaining of chronic fatigue (CF), 1578 CFS patients fulfilled the Fukuda criteria (100% of CFS group) and 951 (60.3% of the CFS group) fulfilled the Holmes criteria. Discriminant function analysis revealed that the Fukuda and Holmes definitions can be differentiated by symptom severity and prevalence. The Holmes definition was more strongly associated than the Fukuda definition with the symptoms that differentiated the CFS patients from the patients that did not comply with the CFS definitions. The inclusion of 10 additional symptoms was found to improve the sensitivity/specificity and accuracy for selection of CFS patients. CONCLUSIONS: The CFS patients fulfilling the Holmes criteria have an increased symptom prevalence and severity of many symptoms. Patients fulfilling the Fukuda criteria were less severely affected patients which leads to an increase in clinical heterogeneity. Addition of certain symptoms and removal of others would strengthen the ability to select CFS patients.
Idiopathic chronic fatigue and chronic fatigue syndrome: a comparison of two case-definitions. Arpino C, Carrieri MP, Valesini G, Pizzigallo E, Rovere P, Tirelli U, Conti F, Dialmi P, Barberio A, Rusconi N, Bosco O, Lazzarin A, Saracco A, Moro ML, Vlahov D. Laboratorio di Epidemiologia e Biostatistica, Istituto Superiore di Sanita, Rome, Italy.
The aim of the study was to compare the signs and symptoms of individuals meeting two different definitions of chronic fatigue syndrome (CFS). Ninety-four patients fitting the eligibility criteria for idiopathic fatigue were enrolled into the study. Of the 94 patients, 48 met the 1988 definition of CFS, 20 the 1994 (but not the 1988) definition of CFS, and 26 met neither definition. The 1994 defined cases were more likely than 1988 defined cases, and non-syndromal individuals to be male, married, and high school educated. The 1994 cases were less likely than 1988 cases to present acute onset, self reported sore throat, mild fever lymphadenopathy, pharyngitis. In conclusion, the 1994 criteria increased the number of patients classified as CFS; however, those who fit only the 1994 criteria were less likely to have an acute symptomatic onset and signs and symptoms suggestive of an infectious process.
U.S. Case Definition of Chronic Fatigue Syndrome: Diagnostic and Theoretical Issues Leonard A. Jason, Caroline P. King, Judith A. Richman, Renee R. Taylor, Susan R. Torres, Sharon Song U.S. Case Definition of Chronic Fatigue Syndrome: Diagnostic and Theoretical Issues
Journal of Chronic Fatigue Syndrome, Vol. 5 (3/4) 1999
SUMMARY. In 1994, researchers from the U.S. Centers for Disease Control and Prevention (CDC) developed a revised case definition of chronic fatigue syndrome (CFS) (1), a complex illness characterized by debilitating fatigue and a number of accompanying flu-like symptoms. Although Fukuda and associates intended to resolve complexities surrounding the classification of individuals with CFS stemming from previous definitional criteria (1), significant problems with the revised criteria endure. This article highlights reliability issues and other conceptual and operational difficulties inherent in the current U.S. definition of CFS (1). We employ case studies derived from a community-based epidemiological study of chronic fatigue syndrome (2) to illustrate examples of the potential for misclassification of individuals with CFS using the current U.S. criteria (1). Moreover, we suggest alternative approaches to classification and ways to operationalize specific concepts embedded in the current U.S. criteria (1).
Defining Chronic Fatigue Syndrome: Methodological Challenges Leonard A. Jason, PhD; Caroline P. King, MA; Renee R. Taylor, PhD; Cara Kennedy, BA Journal of Chronic Fatigue Syndrome, Vol. 7(3) 2000, pp. 17-32 DePaul University.
The lack of operationally explicit criteria has forced health care professionals to rely heavily on their own clinical judgement, which may be biased by personal and highly idiosyncratic factors. Thus, in the case of CFS, the lack of consensus among clinicians regarding the interpretation and application of the diagnostic criteria has likely produced problems in diagnostic reliability.
Data from a recent community based epidemiologic study are presented to illustrate these problems and provide recommendations for improving criterion reliability.
Comparison of the 1988 and 1994 Diagnostic Criteria for Chronic Fatigue Syndrome Leonard A. Jason,(1,2) Susan R. Torres-Harding,(1) Renee R. Taylor,(1) and Adam W. Carrico(1)
In summary, participants meeting the 1988 criteria appear to be a more symptomatic and functionally impaired group than those meeting the 1994 criteria only. Furthermore, these differences do not appear to be influenced by psychiatric variables, as they occurred in the absence of differences in rates of psychiatric comorbidity between the two groups. Taken together, these findings indicate that the 1988 criteria may identify a distinct group of individuals who not only have a higher frequency of CFS symptoms, but also experience greater functional disability. Possibly because of the lesser degree of specificity in criteria, individuals in the 1994 group may comprise more heterogeneous patient groups experiencing more variability and wider ranges of illness severity and functional disability.
Improving the diagnostic criteria and procedures for chronic fatigue syndrome. King C, Jason LA. Spinal Cord Injury Service (128), Hines VA Hospital, P.O. Box 5000, Hines, IL 60141-5128, USA. cpking@rcn.com
Since the publication of the case definition for chronic fatigue syndrome (CFS) in 1988 the diagnostic criteria have been revised twice in the U.S. None of the case definitions were derived empirically. As a result, there is concern regarding the sensitivity, specificity, and reliability of the criteria. The goal of the present study was to identify methods for improving the diagnostic criteria for CFS. Three groups of 15 participants each were recruited: participants with (1) CFS, (2) major depressive disorder (MDD), and (3) healthy controls. Using statistical procedures, three methods for improving the diagnostic criteria were explored: identification of new diagnostic symptoms, the use of severity ratings for symptomatology, and the identification of standardized measures that differentiate cases of CFS from other conditions. Results of the present study suggest that these three methods hold promise for improving the sensitivity, specificity, and reliability of the diagnostic criteria for CFS.
Chronic fatigue syndrome: the need for subtypes. Jason LA, Corradi K, Torres-Harding S, Taylor RR, King C. DePaul University, Chicago, Illinois 60614, USA. ljason@depaul.edu
Chronic fatigue syndrome (CFS) is an important condition confronting patients, clinicians, and researchers. This article provides information concerning the need for appropriate diagnosis of CFS subtypes. We first review findings suggesting that CFS is best conceptualized as a separate diagnostic entity rather than as part of a unitary model of functional somatic distress. Next, research involving the case definitions of CFS is reviewed. Findings suggest that whether a broad or more conservative case definition is employed, and whether clinic or community samples are recruited, these decisions will have a major influence in the types of patients selected. Review of further findings suggests that subtyping individuals with CFS on sociodemographic, functional disability, viral, immune, neuroendocrine, neurology, autonomic, and genetic biomarkers can provide clarification for researchers and clinicians who encounter CFS' characteristically confusing heterogeneous symptom profiles. Treatment studies that incorporate subtypes might be particularly helpful in better understanding the pathophysiology of CFS. This review suggests that there is a need for greater diagnostic clarity, and this might be accomplished by subgroups that integrate multiple variables including those in cognitive, emotional, and biological domains.
Identification of ambiguities in the 1994 chronic fatigue syndrome research case definition and recommendations for resolution Bart Stouten Published 13 May 2005 ©
Background A recent article by Reeves et al. on the identification and resolution of ambiguities in the 1994 chronic fatigue syndrome (CFS) research case definition recommended the Checklist Individual Strength, the Chalder Fatigue Scale, and the Krupp Fatigue Severity Scale for evaluating fatigue in CFS studies. To be able to discriminate between various levels of severe fatigue, extreme scoring on the individual items of these questionnaires must not occur too often. Methods We derived an expression that allows us to compute a lower bound for the number of items with the maximum item score for a given study from the reported mean scale score, the number of reported subjects, and the properties of the fatigue rating scale. Several CFS studies that used the recommended fatigue rating scales were selected from literature and analyzed to verify whether abundant extreme scoring had occurred. Results Extreme scoring occurred on a large number of the items for all three recommended fatigue rating scales across several studies. The percentage of items with the maximum score exceeded 40% in several cases. The amount of extreme scoring for a certain scale varied from one study to another, which suggests heterogeneity in the selected subjects across studies. Conclusions Because all three instruments easily reach the extreme ends of their scales on a large number of the individual items, they do not accurately represent the severe fatigue that is characteristic for CFS. This should lead to serious questions about the validity and suitability of the Checklist Individual Strength, the Chalder Fatigue Scale, and the Krupp Fatigue Severity Scale for evaluating fatigue in CFS research.
Comparing the Fukuda et al. Criteria and the Canadian Case Definition for Chronic Fatigue Syndrome Leonard A. Jason PhD, © Copyrighted by The Haworth Press, Inc
Abstract: Because the pathogenesis of Chronic Fatigue Syndrome (CFS) has yet to be determined, case definitions have relied on clinical observation in classifying signs and symptoms for diagnosis.
The selection of diagnostic signs and symptoms has major implications for which individuals are diagnosed with CFS and how seriously the illness is viewed by health care providers, disability insurers and rehabilitation planners, and patients and their families and friends.
Diagnostic criteria also have implications for whether research based on varying definitions can be synthesized. The current investigation examined differences between CFS as defined by Fukuda et al. (1994) and a set of criteria that has been proposed for a clinical Canadian Case definition.
There were twentythree participants who met the Canadian criteria, 12 in the CFS (Fukuda et al. (7) criteria) group and the 33 from the chronic fatigue (CF)-psychiatric group. Dependent measures included: work status, psychiatric comorbidity, symptoms, and functional impairment (measured by the Medical Outcomes Study). People meeting the Fukuda et al. and Canadian criteria were compared with people who had a chronically fatiguing illness explained by a psychiatric condition. Statistical tests used included binomial logistic regression and analysis of variance.
The Canadian criteria group, in contrast to the Fukuda et al. criteria group, had more variables that statistically significantly differentiated them from the psychiatric comparison group. Overall, there were 17 symptom differences between the Canadian and CF-psychiatric group, but only 7 symptom differences between the CFS and CF-psychiatric group.
The findings suggest that both the Canadian and Fukuda et al. case definitions select individuals who are statistically significantly different from psychiatric controls with chronic fatigue, with the Canadian criteria selecting cases with less psychiatric co-morbidity, more physical functional impairment, and more fatigue/weakness, neuropsychiatric, and neurological symptoms
Research Criteria for Penguins by Peter Kemp
The Need for Research based Subsets from the ME society of America
Progress in understanding myalgic encephalomyelitis/chronic fatigue syndrome will likely result from studying research-based subsets. The following articles either categorize patients according to research-based subsets or argue for the substratification of patients on the basis of subsets. The substratification may include degree-of-illness subsets or subsets based on research findings such as cardiopathology, blood volume and other circulatory disturbances, and various pathogenic causes.
Severe and Very Severe Patients with Chronic Fatigue Syndrome: Perceived Outcome Following an Inpatient Programme Diane L. Cox, PhD, MSc, Dip COT; Leslie J. Findley, OLJ, TD, MD, FRCP, FACP Journal of Chronic Fatigue Syndrome, Vol. 7(3) 2000, pp. 33-47
A conceptual framework to enable an integrated and comprehensive approach to the study of CFS has been defined (1). Historically, many chronic illnesses have been difficult to define, specific causative agents are often unknown and diagnostic laboratory tests often have poor sensitivity and specificity (2,3).
The Fukuda et al. (1) definition has become the most accepted....
However, although the definition states that, ". . . CFS is characterised by severe disabling fatigue . . .," and identifies the subgroups discussed previously, it does not discuss the range of disability and reduced functioning seen within the syndrome (1). In addition, most studies on CFS do not include the more severe presentation of the disease (4-8). In addition, health agencies often do not appear to appreciate the differing level of dysfunction seen within the illness and the consequent impact on daily life (9). This descriptive paper therefore aims to illustrate the perceived outcome of these more severely affected patients following the inpatient programme.
[Article copies available for a fee from The Haworth Document Delivery Service: 1-800-342-9678. E-mail address: getinfo@haworthpressinc.com Website: www.HaworthPress.com ]
Defining an Illness: A Look at the Text and Philosophies of the 1994 Revised Case Definition for Chronic Fatigue Syndrome
It doesn't take an advanced scientific pedigree to realize that what the authors were crafting was a recipe for confusion and conflicting results. It also doesn't take a rocket scientist to come to the conclusion that this is not subgrouping. Failure to classify patients by distinct symptoms has led to a severe loss of respect for the CFS research community.
Descriptions of M.E.
A study of the earliest recorded outbreak of epidemic M.E. in the UK appeared in the Thesis of Dr. Andrew Wallis, a Scottish physician, in 1957. It discusses an epidemic in Cumberland in Northern England in 1955.
Definitions of ME from 1956 onwards
The classic 1959 paper by Sir Donald Acheson, "The clinical syndrome variously called benign myalgic encephalomyelitis, Icelandic disease and epidemic neuromyasthenia". Acheson ED. American Journal of Medicine 1959;569:595." (Reprinted from the American Journal of Medicine, with permission from Excerpta Medica.) from MERGE
http://www.meresearch.org.uk/melibrary/information/index.html
Relevant Books
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