Category: Etiology

Risk factors associated with chronic fatigue syndrome in a cluster of pediatric cases

Abstract:

After seven pediatric cases of chronic fatigue syndrome (CFS) were diagnosed in a farming community in upstate New York, a questionnaire regarding symptoms and potential risk factors of CFS was distributed to all students enrolled in the same school district.

Twenty-one students with symptoms of CFS were identified. Two controls per case matched for age and sex were randomly selected from questionnaire respondents. Health status was verified for all subjects by telephone, and diagnosis of CFS was confirmed by a physician.

Information was collected on the following factors: symptoms of CFS among other family members; history of allergy/asthma; consumption of raw milk, raw eggs, raw cheese, or raw meat; water supply; exposure to animals; home heating source; proximity to farmland/orchards; tick bite; blood transfusion; camping; and appendicitis.

Logistic-regression analyses indicated that the best model (characterized by symptoms among other family members, recent ingestion of raw milk, and history of allergy/asthma) produced significant estimates of relative risk (P less than .05) of 35.9, 44.3, and 23.3, respectively, for the three factors (corrections were made for the effect of the other covariates).

These data suggest that a combination of host and environmental factors, including an infectious agent or agents, are involved in the etiology of CFS.

 

Source: Bell KM, Cookfair D, Bell DS, Reese P, Cooper L. Risk factors associated with chronic fatigue syndrome in a cluster of pediatric cases. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S32-8. http://www.ncbi.nlm.nih.gov/pubmed/2020801

 

Chronic fatigue syndrome: thoughts on pathogenesis

Abstract:

Studies have shown that a proportion of patients with severe chronic infection due to Epstein-Barr virus (EBV) lack antibody to a component of EBV nuclear antigen. However, it is not clear whether this circumstance is one of cause or effect in regard to the pathogenesis of chronic fatigue syndrome (CFS); it is clearly not pathognomonic since it also occurs in persons infected with the human immunodeficiency virus and–rarely–in those with other EBV-related conditions. Stress and depression may be other pathogenetic mechanisms that could reactivate EBV and lead to CFS; examples of this phenomenon are given. The syndrome might also follow certain other viral infections as part of a process that has been called postinfectious neurasthenia. Currently, the cause(s) and cure of CFS, a common and distressing syndrome, are enigmatic and require multidisciplinary study.

 

Source: Evans AS. Chronic fatigue syndrome: thoughts on pathogenesis. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S56-9. http://www.ncbi.nlm.nih.gov/pubmed/1850544

 

Serologic and immunologic responses in chronic fatigue syndrome with emphasis on the Epstein-Barr virus

Abstract:

Although patients with chronic fatigue syndrome (CFS) can be diagnosed by clinical criteria, the lack of specific laboratory criteria delays or prevents the diagnosis and contributes to the quasi-disease status of the syndrome.

A resurgence of interest in the syndrome has followed reports suggesting that CFS may be associated with chronic active infection due to the Epstein-Barr virus. Analysis of reports to date shows that the mean titers of antibodies to viral capsid antigen and to early antigen are greater for patients with CFS than for healthy individuals; this is particularly evident in cases for which serial samples were tested.

However, these differences do not prove the cause of CFS. Cell-mediated immune responses in patients with CFS vary from study to study, and the number and function of natural killer cells in those patients are the most variable factors. Rates of isolation of virus from saliva do not differ, but in one comparison study with a large number of subjects, more lymphocytes that contained virus were isolated from patients than from controls.

Other viruses, such as the Coxsackie B virus, have been implicated as causes of CFS in studies from Great Britain. The use of a working definition of CFS and standardized tests to address abnormalities revealed by laboratory tests among homogeneous populations should allow determination of useful tests for the diagnosis of CFS and studies of its mechanisms.

 

Source:  Jones JF. Serologic and immunologic responses in chronic fatigue syndrome with emphasis on the Epstein-Barr virus. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S26-31. http://www.ncbi.nlm.nih.gov/pubmed/1850541

 

Analysis of clinical, epidemiologic, and laboratory data on chronic fatigue syndrome

Abstract:

Much of the research conducted on chronic fatigue syndrome (CFS) is exploratory. The researchers’ overall goal is to use clinical, epidemiologic, and laboratory data to provide clues about the etiology of this syndrome. In preparation for this symposium, a review of numerous publications on CFS has indicated that the literature generally does not reflect the application of optimal statistical methods for exploration of data.

Whenever the researchers’ aim is to generate hypotheses, modern methods designed specifically for exploratory data analysis are likely to provide greater insights into any patterns of data than are the traditional approaches to hypothesis testing. In addition, the use of formal methods of data synthesis for ongoing and future research on CFS is a means of strengthening collaborative efforts and of improving the ability of researchers to interpret the evidence available that relates to specific etiologic factors. The inclusion on the research team of experienced biostatisticians, who would oversee the statistical methods and the development of innovative analyses, is recommended.

 

Source: Redmond CK. Analysis of clinical, epidemiologic, and laboratory data on chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S90-3. http://www.ncbi.nlm.nih.gov/pubmed/1826967

 

The chronic fatigue syndrome: a reappraisal and unifying hypothesis

Abstract:

The chronic fatigue syndrome is one of the most common medical problems in Western countries. Research work in virology, immunology, metabolic medicine and psychiatry in this area is reviewed and a disease model proposed. The chronic fatigue syndrome can be considered as a continuum ranging from cases with chronic viraemia on the one hand to instances of frank psychiatric illness on the other. In the majority of patients the fully evolved syndrome may involve an interaction of premorbid factors (psychological, immunological), environmental trigger factors (virus) and enhancing factors (emotional response to illness). A Venn diagram is a convenient way of expressing this concept.

 

Source: Byrne E. The chronic fatigue syndrome: a reappraisal and unifying hypothesis. Clin Exp Neurol. 1991;28:128-38. http://www.ncbi.nlm.nih.gov/pubmed/1821821

 

Mitochondrial abnormalities in the postviral fatigue syndrome

Abstract:

We have examined the muscle biopsies of 50 patients who had postviral fatigue syndrome (PFS) for from 1 to 17 years. We found mild to severe atrophy of type II fibres in 39 biopsies, with a mild to moderate excess of lipid.

On ultrastructural examination, 35 of these specimens showed branching and fusion of mitochondrial cristae. Mitochondrial degeneration was obvious in 40 of the biopsies with swelling, vacuolation, myelin figures and secondary lysosomes. These abnormalities were in obvious contrast to control biopsies, where even mild changes were rarely detected.

The findings described here provide the first evidence that PFS may be due to a mitochondrial disorder precipitated by a virus infection.

 

Source: Behan WM1, More IA, Behan PO. Mitochondrial abnormalities in the postviral fatigue syndrome. Acta Neuropathol. 1991;83(1):61-5. http://www.ncbi.nlm.nih.gov/pubmed/1792865

 

Dual infections of the immune system in patients with chronic active Epstein-Barr virus infection mimicking chronic fatigue syndrome

Abstract:

The etiologic bases of CFS are undetermined at the present time. It is very important to distinguish the patients with CFS as defined by the Centers for Disease Control (CDC) case definition of Holmes et al. from patients with physical and laboratory findings suggesting dual infections and/or underlying immunodeficiency. Particularly fruitful might be a longitudinal immunovirologic study of patients who exhibit CFS following a well-documented viral infection.

 

Source: Purtilo DT. Dual infections of the immune system in patients with chronic active Epstein-Barr virus infection mimicking chronic fatigue syndrome. Can Dis Wkly Rep. 1991 Jan;17 Suppl 1E:29-32. http://www.ncbi.nlm.nih.gov/pubmed/1669350

 

Life insurance MDs sceptical when chronic fatigue syndrome diagnosed

Comment on: Life insurance MDs sceptical when chronic fatigue syndrome diagnosed. [CMAJ. 1990]

 

As a physician with chronic fatigue syndrome (CFS) since the early days of the Lake Tahoe, Calif., outbreak, in 1984, I read Olga Lechky’s report (Can MedAssoc J 1990; 143: 413- 415) with particular interest. It was refreshing to hear Dr. Richard Proschek, assistant medical director of Mutual Life of Canada, admit that the industry’s attitude to CFS is one of hostility. Unfortunately for the thousands of severely debilitated patients with the condition this scepticism and hostility are not restricted to that industry, which in many instances has behaved with compassion and responsibility toward its clients. The hostile viewpoint is also widely prevalent in the medical profession and is often freely communicated to patients.

To hold that CFS is not a real disease it is necessary to imagine that in 1984 people of all ages began to manufacture a condition with clearly defined symptoms that begins as a flu-like illness, persists and evolves. How many diseases fit this description? When, before 1984, did depression present so? Can it be true that thousands of our brightest citizens, including children, Olympic aspirants, several members of some families, alarming numbers of teachers, 50% of a symphony orchestra and 10% of the population of Incline Village, Nev., abruptly and concurrently elected to drop out of life, then continued to complain in the face of widespread scepticism, hostility, marital breakdown and, frequently, isolation? What, other than an infectious agent, could cause this?

Proschek’s bias arises from his position. Physicians in practice, however, see many CFS patients who have no insurance or are quite wealthy. The degree to which imagination must extend to accommodate a diagnosis of secondary gain in these people is beyond belief. Many physicians lament the lack of a blood test for CFS. What, pray, is the test for malingering, a diagnosis we seem to have no difficulty making?

You can read the rest of this letter here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1452931/pdf/cmaj00229-0013.pdf

 

Source: Sean J. O’Sullivan, MD. Life insurance MDs sceptical when chronic fatigue syndrome diagnosed. CMAJ. 1990 Dec 15;143(12):1283-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1452931/

 

Is chronic fatigue syndrome synonymous with effort syndrome?

Abstract:

Chronic fatigue syndrome (CFS), including myalgic encephalomyelitis (ME) and postviral syndrome (PVS), is a term used today to describe a condition of incapacity for making and sustaining effort, associated with a wide range of symptoms. None of the reviews of CFS has provided a proper consideration of the effort syndrome caused by chronic habitual hyperventilation.

In 100 consecutive patients, whose CFS had been attributed to ME or PVS, the time course of their illness and the respiratory psychophysiological studies were characteristic of chronic habitual hyperventilation in 93.

It is suggested that the labels ‘CFS’, ‘ME’ or ‘PVS’ should be withheld until chronic habitual hyperventilation – for which conventional rehabilitation is available – has been definitively excluded.

 

Source: Rosen SD, King JC, Wilkinson JB, Nixon PG. Is chronic fatigue syndrome synonymous with effort syndrome? J R Soc Med. 1990 Dec;83(12):761-4. http://www.ncbi.nlm.nih.gov/pubmed/2125315

 

Hyperventilation disorders

Hyperventilation syndrome falls into the shadowy hinterland between physiology, psychiatry, psychology and medicine. In this respect it joins a long list of syndromes from the past of which effort syndrome is just one example. Myalgic encephalomyelitis (ME) and postviral fatigue syndrome are recent attempts to impose a unitary definition on what is probably a complex interaction between many different organic and psychological factors. The recent introduction of terms such as somatization disorder recognize this aetiological heterogeneity (1).

The symptoms of hypocapnia induced by voluntary overbreathing were first described by Haldane in 1908, the first case of spontaneous hyperventilation by Goldman in 1922 (2), and the term Hyperventilation Syndrome was first used by Dalton, Kerr and Gliebe in 1937 to describe patients with symptoms both of hypocapnia and anxiety (3). Since then, many different interpretations of this term have appeared in the literature encompassing patients with widely different aetiologies. Much research in this area is bedevilled by failure to define clearly the detailed characteristics of the patients studied; by the assumption of definitions for which there is no universal agreement; and by the presentation of scientifically unsound data lacking in rigorous quantitative proof and with perpetuation of circular arguments. The papers in this issue of the journal make a commendable attempt to reintroduce the reader to the historical perspectives of this subject and to clarify some of the issues, but unfortunately also have some of the shortcomings common to so many of the studies in this very difficult field.

You can read the rest of this article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1292944/pdf/jrsocmed00129-0005.pdf

 

Source: Gardner W. Hyperventilation disorders. J R Soc Med. 1990 Dec;83(12):755-7. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1292944/