Cognitive and mood-state changes in patients with chronic fatigue syndrome

Abstract:

In this paper the cognitive and psychiatric impairments associated with chronic fatigue syndrome (CFS) and related disorders are reviewed. It is concluded that while acute mononucleosis and infection with Epstein-Barr virus occasionally result in impaired cognition, such changes have not yet been objectively verified in patients with CFS.

However, when patients with CFS are carefully studied, concurrent or premorbid psychiatric disorders are revealed at a greater than chance level. Finally, some suggestions are offered regarding improved neuropsychological assessment of fatigue, concentration, and attention for patients with CFS. The findings to date, while suggesting that psychological predisposition may play a role in the expression of CFS, are still inconclusive regarding the etiology of CFS.

 

Source: Grafman J, Johnson R Jr, Scheffers M. Cognitive and mood-state changes in patients with chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S45-52. http://www.ncbi.nlm.nih.gov/pubmed/1850543

 

Primary fibromyalgia and the chronic fatigue syndrome

Abstract:

Thirty-three primary fibromyalgia patients were investigated for chronic fatigue syndrome symptoms. Significant fatigue was reported by 21/33 patients (63.6%), and patients reported various flulike symptoms, yet only 7/33 patients (21.2%) fulfilled criteria for the chronic fatigue syndrome. Only one patient reported painful lymph glands and four patients reported fever. Thus, symptoms of painful glands or fever might serve as clinical indicators, distinguishing between fibromyalgia and the chronic fatigue syndrome.

 

Source: Wysenbeek AJ, Shapira Y, Leibovici L. Primary fibromyalgia and the chronic fatigue syndrome. Rheumatol Int. 1991;10(6):227-9. http://www.ncbi.nlm.nih.gov/pubmed/2041979

 

Physiologic measurement of exercise and fatigue with special reference to chronic fatigue syndrome

Abstract:

Oxidative metabolism is the major source of energy for muscle activity, and maximal oxygen uptake (VO2max), the product of maximal cardiac output and maximal arteriovenous oxygen difference, indicates individual capacity for oxidative metabolism and performance of exercise by the large muscles.

Strength, a function of muscle cross-sectional area, motor-unit recruitment, and neuromuscular coordination, is the ability to develop force in a single, brief, maximal-effort voluntary contraction of rested muscle. Weakness is a diminished ability of rested muscle to exert maximal force. Fatigue is a loss of maximal force-generating capacity that develops during muscular activity, likely originates within muscle itself, and persists until muscle is fully recovered. Individual perception of motor effort can be determined with standardized rating scales.

These concepts are discussed in detail, their relevance to the pathophysiology of exercise in chronic fatigue syndrome is analyzed, and a general strategy of exercise evaluation pertinent to chronic fatigue syndrome is presented.

 

Source: Lewis SF, Haller RG. Physiologic measurement of exercise and fatigue with special reference to chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S98-108. http://www.ncbi.nlm.nih.gov/pubmed/2020810

 

Validation of biologic markers for use in research on chronic fatigue syndrome

Abstract:

Unresolved aspects of chronic fatigue syndrome can be addressed by research involving biologic markers. These may be any molecular, biochemical, physiological, or other biologic parameter obtainable from biologic specimens. The use of biologic markers in research requires their validation as dependent or independent variables. Additionally, other characteristics of markers such as reliability of assays, background level, confounding factors, interpretations, and legal and ethical implications should be considered before the use of markers in research. A checklist is provided for evaluating a biologic marker before its inclusion in research.

 

Source: Schulte PA. Validation of biologic markers for use in research on chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S87-9. http://www.ncbi.nlm.nih.gov/pubmed/2020808

 

Symptoms and signs of chronic fatigue syndrome

Abstract:

This review summarizes the symptoms and signs seen in patients with chronic fatigue syndrome (CFS). It is based on the authors’ experience with two cohorts of approximately 510 patients with chronic debilitating fatigue and on the reported experience of other investigators with similar patients.

The most characteristic symptoms of CFS are the sudden onset of an infectious-type illness, the subsequent chronic and debilitating fatigue, and postexertional malaise; many patients also have recurrent fevers, pharyngitis, adenopathy, myalgias, sleep disorders, and cognitive impairment.

 

Source: Komaroff AL, Buchwald D. Symptoms and signs of chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S8-11. http://www.ncbi.nlm.nih.gov/pubmed/2020806

 

Chronic fatigue syndrome: issues in the diagnosis and estimation of incidence

Abstract:

This article critiques the current working definition of chronic fatigue syndrome. The concerns raised about the current working definition are the following: prolonged or excessive exertion is not addressed explicitly; duration and quality of bed rest are not specified; a socioeconomic ascertainment bias is present; data from history and physical findings are not clearly separated and are relegated to minor criteria; and the rigor of neurologic and psychiatric evaluations is not specified.

We propose a flow chart that addresses the possible modes of evolution of chronic fatigue syndrome for patients; this chart may yield more homogeneous subgroups of individuals with this syndrome or enable some patients to avert the syndrome.

 

Source: Armon C, Kurland LT. Chronic fatigue syndrome: issues in the diagnosis and estimation of incidence. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S68-72. http://www.ncbi.nlm.nih.gov/pubmed/2020804

 

Issues and problems in the conduct of epidemiologic research on chronic fatigue syndrome

Abstract:

The epidemiologic research approach is perhaps most appropriate for initial studies of chronic fatigue syndrome since the syndrome is vaguely defined, scientific knowledge about it is limited, and an infectious etiology is suspected.

Several priority needs appropriate for epidemiologic research are identified, including a refinement of diagnostic criteria; a greater understanding of the natural history of the syndrome; basic incidence, prevalence, and mortality statistics; information on whether asymptomatic cases exist; etiologic studies of possible heterogeneity of cases; investigations of clusters of cases; and determinations of whether patients with the syndrome have an increased risk of malignancy.

Because of the lack of cogent etiologic hypotheses regarding the syndrome, case-control studies are identified as a high priority for research. The many difficulties encountered in conducting such research are discussed and approaches to dealing with these problems are suggested.

 

Source: Grufferman S. Issues and problems in the conduct of epidemiologic research on chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S60-7. http://www.ncbi.nlm.nih.gov/pubmed/2020803

 

Defining the chronic fatigue syndrome

Abstract:

The recently published working definition of the chronic fatigue syndrome (CFS) is a necessary first step toward a consistent effort to research this controversial illness. Before this definition was developed, cases often were defined vaguely, according to the perceptions and biases of the individual researchers, so that the results of some studies were unclear. However, few specific diagnostic parameters for CFS exist, and the new definition may not delineate a single clinicopathologic entity.

Future efforts at researching this illness should be aimed at identifying parameters that differentiate CFS from psychiatric conditions such as major depression and from other defined chronic diseases. Because CFS may be the result of multiple disease processes, the separate study of well-defined subgroups of patients with CFS is appropriate.

Such subgroups of patients are probably more likely to have common pathogenetic features than are patients with CFS as a whole group.

 

Source: Holmes GP. Defining the chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S53-5. http://www.ncbi.nlm.nih.gov/pubmed/2020802

 

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

 

Medical aspects of delayed convalescence

Abstract:

Disease and illness are not synonymous. In most instances, disease is demonstrable by anatomic, physiologic, biochemical, microbiologic, or immunologic abnormalities. Disease is a pathologic process. Not all persons with a disease are sick or ill. Symptoms of illness associated with a disease may be manifest or persist after the disease has disappeared.

The absence of demonstrable disease, however, does not necessarily mean that symptoms of illness are unreal. Recovery from disease and recovery from illness are not always equated. Many factors, including personal characteristics and social circumstances, can be responsible for recovery from disease and illness.

Chronic fatigue syndrome or symptoms of illness can persist in some patients but not in others after many different diseases.

 

Source: Cluff LE. Medical aspects of delayed convalescence. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S138-40.  http://www.ncbi.nlm.nih.gov/pubmed/2020799