Functional status in patients with chronic fatigue syndrome, other fatiguing illnesses, and healthy individuals

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a condition that may be associated with substantial disability. The Medical Outcomes Study Short-Form General Health Survey (SF-36) is an instrument that has been widely used in outpatient populations to determine functional status. Our objectives were to describe the usefulness of the SF-36 in CFS patients and to determine if subscale scores could distinguish patients with CFS from subjects with unexplained chronic fatigue (CF), major depression (MD), or acute infectious mononucleosis (AIM), and from healthy control subjects (HC). An additional goal was to ascertain if subscale scores correlated with the signs and symptoms of CFS or the presence of psychiatric disorders and fibromyalgia.

DESIGN: Prospectively collected case series.

SETTING: Patients with CFS and CF were seen in a university-based referral clinic and had undergone a complete medical and psychiatric evaluation. Other study subjects were recruited from the community to participate in research studies.

PARTICIPANTS: The study included 185 patients with CFS, 246 with CF, 111 with AIM, and 25 with MD. There were 99 HC subjects.

MEASURES: The SF-36 and a structured psychiatric interview were used. The SF-36 contains 8 subscales: physical, emotional, social, and role functioning, body pain, mental health, vitality, and general health- and a structured psychiatric interview.

RESULTS: Performance characteristics (internal reliability coefficients, convergent validity) of the SF-36 were excellent. A strikingly consistent pattern was found for the physical functioning, role functioning, social functioning, general health, and body pain subscales, with the lowest scores in CFS patients, intermediate scores in AIM patients, and the highest scores in the HC subjects. The CFS patients had significantly lower scores than patients with CF alone on the physical functioning (P < or = 0.01), role functioning (P < or = 0.01), and body pain (P < or = 0.001) subscales. The emotional functioning and mental health scores were worst among those with MD. The presence of fibromyalgia, being unemployed, and increasing fatigue severity all were associated with additional functional limitations across multiple functional domains, with increasing fatigue appearing to have the greatest effect.

CONCLUSIONS: The SF-36 is useful in assessing functional status in patients with fatiguing illnesses. Patients with CFS and CF have marked impairment of their functional status. The severity and pattern of impairment as documented by the SF-36 distinguishes patients with CFS and CF from those with MD and AIM, and from HC, but does not discriminate between CF and CFS.

 

Source: Buchwald D, Pearlman T, Umali J, Schmaling K, Katon W. Functional status in patients with chronic fatigue syndrome, other fatiguing illnesses, and healthy individuals. Am J Med. 1996 Oct;101(4):364-70. http://www.ncbi.nlm.nih.gov/pubmed/8873506

 

Chronic fatigue syndrome. Definition, diagnostic measures and therapeutic possibilities

Abstract:

This article reviews the chronic fatigue syndrome (CFS), a disorder whose etiology is unknown. The diagnostic criteria proposed in 1994 by the CDC and the International Chronic Fatigue Syndrome Study Group are introduced.

In contrast to widespread belief, there are no laboratory tests available to underpin the diagnosis of CFS; the diagnosis is made solely on the basis of clinical criteria. In the differential diagnosis, the exclusion of other conditions that can cause chronic fatigue, such as neuropsychiatric or sleep disorders, is of critical importance.

In this context, the question as to whether CFS is a clinical entity that can be differentiated from psychiatric diagnoses, such as depression, somatoform disorder, or neurasthenia, is discussed. At the moment, there is no specific therapy for CFS. Therefore, therapeutic approaches are limited to symptomatic management of the concomitant sleep disturbances, pain, or psychiatric symptoms, such as depression.

Patients may benefit from cognitive behavioral therapy, as this may help then to identify and exclude factors contributing to and maintaining chronic fatigue. An integrated medical and psychological approach should be adopted, with the aim of preventing significant secondary negative results of the illness, such as interpersonal conflicts or chronic disability.

Comment in: “Chronic fatigue syndrome“. Nervenarzt. 1997

 

Source: Lieb K, Dammann G, Berger M, Bauer J. Chronic fatigue syndrome. Definition, diagnostic measures and therapeutic possibilities. Nervenarzt. 1996 Sep;67(9):711-20. [Article in German] http://www.ncbi.nlm.nih.gov/pubmed/8992368

 

Research on cognitive complaints and cognitive functioning in patients with chronic fatigue syndrome (CFS): What conclusions can we draw?

Abstract:

People with chronic fatigue syndrome (CFS) complain of difficulties with concentration and memory yet studies suggest that they do not suffer gross deficits in cognitive functioning. Depressed patients make similar cognitive complaints, and there is symptomatic overlap between CFS and depression.

Cognitive complaints and depressed mood are positively correlated in CFS patients but, except on tasks which are particularly sensitive to depression, cognitive performance and depression are not.

The inconsistency between cognitive complaints and results of tests of cognitive functioning resembles that found in other subject groups and may be due in part to the inappropriate use of laboratory memory tests for assessing “everyday” cognitive functioning.

Even when cognitive capacity is intact, cognitive performance may be affected by factors such as arousal, mood, and strategy. In CFS patients, everyday cognitive tasks may require excessive processing resources leaving patients with diminished spare attentional capacity or flexibility.

 

Source: Wearden AJ, Appleby L. Research on cognitive complaints and cognitive functioning in patients with chronic fatigue syndrome (CFS): What conclusions can we draw? J Psychosom Res. 1996 Sep;41(3):197-211. http://www.ncbi.nlm.nih.gov/pubmed/8910243

 

Health status in patients with chronic fatigue syndrome and in general population and disease comparison groups

Abstract:

PURPOSE: To measure the functional status and well-being of patients with chronic fatigue syndrome (CFS), and compare them with those of a general population group and six disease comparison groups.

PATIENTS AND METHODS: The subjects of the study were patients with CFS (n = 223) from a CFS clinic, a population-based control sample (n = 2,474), and disease comparison groups with hypertension (n = 2,089), congestive heart failure (n = 216), type II diabetes mellitus (n = 163), acute myocardial infarction (n = 107), multiple sclerosis (n = 25), and depression (n = 502). We measured functional status and well-being using the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36), which is a self-administered questionnaire in which lower scores are indicative of greater impairment.

RESULTS: Patients with CFS had far lower mean scores than the general population control subjects on all eight SF-36 scales. They also scored significantly lower than patients in all the disease comparison groups other than depression on virtually all the scales. When compared with patients with depression, they scored significantly lower on all the scales except for scales measuring mental health and role disability due to emotional problems, on which they scored significantly higher. The two SF-36 scales reflecting mental health were not correlated with any of the symptoms of CFS except for irritability and depression.

CONCLUSION: Patients with CFS had marked impairment, in comparison with the general population and disease comparison groups. Moreover, the degree and pattern of impairment was different from that seen in patients with depression.

 

Source: Komaroff AL, Fagioli LR, Doolittle TH, Gandek B, Gleit MA, Guerriero RT, Kornish RJ 2nd, Ware NC, Ware JE Jr, Bates DW. Health status in patients with chronic fatigue syndrome and in general population and disease comparison groups. Am J Med. 1996 Sep;101(3):281-90. http://www.ncbi.nlm.nih.gov/pubmed/8873490

 

Depression in fatiguing illness: comparing patients with chronic fatigue syndrome, multiple sclerosis and depression

Abstract:

Because depression is commonly observed in the chronic fatigue syndrome (CFS), the present study sought to determine whether the symptom pattern is similar to that seen in clinically depressed subjects (DEP). Individuals with multiple sclerosis (MS) were chosen as an additional comparison group because MS is a fatiguing illness of known organic etiology. The Beck Depression Inventory (BDI) was used to compare categories of depressive symptomatology.

Absolute scores on the BDI were higher for the depressed group on mood and self-reproach symptoms, but were not higher than the CFS group on somatic and vegetative items. Analysis of symptoms as a percentage of total BDI score revealed no significant differences in mood or vegetative items among the three groups. The CFS and MS groups exhibited a significantly lower percentage of self-reproach symptoms than DEP, whereas the DEP group showed a lower percentage of somatic symptoms than the CFS and MS groups.

 

Source: Johnson SK, DeLuca J, Natelson BH. Depression in fatiguing illness: comparing patients with chronic fatigue syndrome, multiple sclerosis and depression. J Affect Disord. 1996 Jun 20;39(1):21-30. http://www.ncbi.nlm.nih.gov/pubmed/8835650

 

Memory, attention, and executive function in chronic fatigue syndrome

Abstract:

OBJECTIVES: To examine cognitive function in chronic fatigue syndrome.

METHODS: Twenty patients with chronic fatigue syndrome recruited from primary care and 20 matched normal controls were given CANTAB computerised tests of visuospatial memory, attention, and executive function, and verbal tests of letter and category fluency and word association learning.

RESULTS: Patients with chronic fatigue syndrome were impaired, predominantly in the domain of memory but their pattern of performance was unlike that of patients with amnesic syndrome or dementia. They were normal on tests of spatial pattern recognition memory, simultaneous and delayed matching to sample, and pattern-location association learning. They were impaired on tests of spatial span, spatial working memory, and a selective reminding condition of the pattern-location association learning test. An executive test of planning was normal. In an attentional test, eight subjects with chronic fatigue syndrome were unable to learn a response set; the remainder exhibited no impairment in the executive set shifting phase of the test. Patients with chronic fatigue syndrome were also impaired on verbal tests of unrelated word association learning and letter fluency.

CONCLUSION: Patients with chronic fatigue syndrome have reduced attentional capacity resulting in impaired performance on effortful tasks requiring planned or self ordered generation of responses from memory.

Source: Joyce E, Blumenthal S, Wessely S. Memory, attention, and executive function in chronic fatigue syndrome. J Neurol Neurosurg Psychiatry. 1996 May;60(5):495-503. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC486360/ (Full article)

Neuroimaging in chronic fatigue syndrome

The link between viral infection, the brain, and fatiguing illnesses has a long history. This combination forced itself on the medical imagination after events in Austria in the winter of 1916-17. A virulent form of influenza was noted, characteristically, to produce lethargy and later, to leave a host of neurological deficits in its wake. By the spring of 1918 several English cases of encephalitis lethargica had been reported and in the next year the disease was notifiable. The peak of the epidemic occurred in 1924 in the United Kingdom, at which time the Board of Control reported that many cases had been admitted to hospital with psychiatric disturbances.1 Hence the notion that apparent psychiatric illnesses may be misdiagnosed manifestations of a postinfectious cerebral disease began; it refuses to disappear.23

You can read the rest of this article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC486356/pdf/jnnpsyc00017-0001.pdf

 

Source: Cope H, David AS. Neuroimaging in chronic fatigue syndrome. J Neurol Neurosurg Psychiatry. 1996 May;60(5):471-3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC486356/

 

A case-control study to assess possible triggers and cofactors in chronic fatigue syndrome

Abstract:

PURPOSE: To assess possible triggers and cofactors for chronic fatigue syndrome (CFS) and to compare levels of selected cytokines between cases and an appropriately matched control group.

PATIENTS AND METHODS: We conducted a case-control study of 47 cases of CFS obtained through a regional CFS research program maintained at a tertiary care medical center. One age-, gender-, and neighborhood-matched control was identified for each case through systematic community telephone sampling. Standardized questionnaires were administered to cases and controls. Sera were assayed for transforming growth factor-beta (TGF-beta), interleukin-1 beta, interleukin-6, tumor necrosis factor-alpha, and antibody to Borrelia burgdorferi and Babesia microti.

RESULTS: Cases were more likely to have exercised regularly before illness onset than controls (67% versus 40%; matched odds ratio (MOR) = 3.4; 95% CI = 1.2 to 11.8; P = 0.02). Female cases were more likely to be nulliparous prior to onset of CFS than controls (51% versus 31%; MOR = 8.0; 95% CI = 1.03 to 170; P = 0.05). History of other major factors, including silicone-gel breast implants (one female case and one female control), pre-morbid history of depression (15% of cases, 11% of controls) and history of allergies (66% of cases, 51% of controls) were similar for cases and controls. However, cases were more likely to have a diagnosis of depression subsequent to their diagnosis of CFS compared to a similar time frame for controls (MOR = undefined; 95% CI lower bound = 2.5; P < 0.001). Positive antibody titers to B burgdorferi (one case and one control) and B microti (zero cases and two controls) were also similar.

CONCLUSIONS: Further investigation into the role of prior routine exercise as a cofactor for CFS is warranted. This study supports the concurrence of CFS and depression, although pre-morbid history of depression was similar for both groups.

Comment in: Etiology of chronic fatigue syndrome. [Am J Med. 1997]

 

Source: MacDonald KL, Osterholm MT, LeDell KH, White KE, Schenck CH, Chao CC, Persing DH, Johnson RC, Barker JM, Peterson PK. A case-control study to assess possible triggers and cofactors in chronic fatigue syndrome. Am J Med. 1996 May;100(5):548-54. http://www.ncbi.nlm.nih.gov/pubmed/8644768

 

Randomized, double blind, controlled placebo-phase in trial of low dose phenelzine in the chronic fatigue syndrome

Abstract:

Because of the striking similarity of the clinical manifestations produced by use of the drug reserpine and seen in patients with the chronic fatigue syndrome (CFS), we theorized that CFS was a disorder of reduced central sympathetic drive. Because of the pharmacology of control of this central sympathetic system, we further postulated that CFS symptoms would respond quickly to low dose treatment with a monamine oxidase inhibitor. To test these hypotheses, we designed a randomized, double blind placebo controlled study using phenelzine.

No patient in the trial had a diagnosis of lifetime or current psychiatric disorder and none had depressed mood in the range of clinically depressed patients on a paper and pencil test of depression. Patients in the placebo group received placebo for 6 weeks while those in the drug treatment group were treated in three 2-week segments-placebo, 15 mg phenelzine every other day, and then 15 mg daily. This treatment regimen produced a significant pattern of improvement compared to worsening in 20 self report vehicles of CFS symptoms, illness severity, mood or functional status.

Thus the data support our hypothesis of reduced sympathetic drive, although an alternative hypothesis of pain alleviation is also possible. The study design also allowed us to evaluate patients for a placebo effect: no evidence for this was found, suggesting that CFS is not an illness due to patients’ being overly suggestible.

 

Source: Natelson BH, Cheu J, Pareja J, Ellis SP, Policastro T, Findley TW. Randomized, double blind, controlled placebo-phase in trial of low dose phenelzine in the chronic fatigue syndrome. Psychopharmacology (Berl). 1996 Apr;124(3):226-30. http://www.ncbi.nlm.nih.gov/pubmed/8740043

 

Randomised, double-blind, placebo-controlled study of fluoxetine in chronic fatigue syndrome

Abstract:

BACKGROUND: No somatic treatment has been found to be effective for chronic fatigue syndrome (CFS). Antidepressant therapy is commonly used. Fluoxetine is recommended in preference to tricyclic agents because it has fewer sedative and autonomic nervous system effects. However, there have been no randomised, placebo-controlled, double-blind studies showing the effectiveness of antidepressant therapy in CFS. We have carried out such a study to assess the effect of fluoxetine in depressed and non-depressed CFS patients.

METHODS: In this randomised, double-blind study, we recruited 44 patients to the depressed CFS group, and 52 to the non-depressed CFS group. In each group participants were randomly assigned to receive either fluoxetine (20 mg once daily) or placebo for 8 weeks. The effect of fluoxetine was assessed by questionnaires, self-observation lists, standard neuropsychological tests, and a motion-sensing device (Actometer), which were applied on the day treatment started and on the last day.

FINDINGS: The two groups were well matched in terms of age, sex distribution, employment and marital status, and duration of CFS. There were no significant differences between the placebo and fluoxetine-treated groups in the change during the 8-week treatment period for any dimension of CFS. There was no change in subjective assessments of fatigue, severity of depression, functional impairment, sleep disturbances, neuropsychological function, cognitions, or physical activity in the depressed or the non-depressed subgroup.

INTERPRETATION: Fluoxetine in a 20 mg daily dose does not have a beneficial effect on any characteristic of CFS. The lack of effect of fluoxetine on depressive symptoms in CFS suggests that processes underlying the presentation of depressive symptoms in CFS may differ from those in patients with major depressive disorder.

 

Source: Vercoulen JH, Swanink CM, Zitman FG, Vreden SG, Hoofs MP, Fennis JF, Galama JM, van der Meer JW, Bleijenberg G. Randomised, double-blind, placebo-controlled study of fluoxetine in chronic fatigue syndrome. Lancet. 1996 Mar 30;347(9005):858-61. http://www.ncbi.nlm.nih.gov/pubmed/8622391