Chronic fatigue syndrome: point and counterpoint

Abstract:

Two clinical investigators with divergent views on chronic fatigue syndrome (CFS) were invited to debate their positions at the 1993 annual meeting of The Infectious Disease Society of America. Major points of the discourse focused on the value of the US Centers for Disease Control and Prevention case definition of CFS, the potential roles of infectious and allergic problems in the syndrome, the confounding problem of concurrent psychiatric problems, and the utility of diagnostic tests.

 

Source: Straus SE, Komaroff AL, Wedner HJ. Chronic fatigue syndrome: point and counterpoint. J Infect Dis. 1994 Jul;170(1):1-6. http://www.ncbi.nlm.nih.gov/pubmed/8014482

 

SPECT imaging of the brain: comparison of findings in patients with chronic fatigue syndrome, AIDS dementia complex, and major unipolar depression

Abstract:

OBJECTIVE: Chronic fatigue syndrome is an illness of unknown origin that begins abruptly with a flulike state and has symptoms suggesting both a chronic viral encephalitis and an affective disorder. We compared single-photon emission computed tomography (SPECT) scans of patients with chronic fatigue syndrome with those of patients with AIDS dementia complex and unipolar depression.

SUBJECTS AND METHODS: We used 99mTc-hexamethylpropyleneamine oxime to examine 45 patients with chronic fatigue syndrome, 27 patients with AIDS dementia complex, and 14 patients with major unipolar depression. Scans of 38 healthy persons were used as controls. Comparison of regional defects between groups, as well as midcerebral uptake indexes (an objective measure of global radionuclide uptake), was performed by using analysis of variance with the Student-Newman-Keuls option. Correlation between the number of regional defects and the midcerebral uptake index was determined by using the Spearman rank-correlation test.

RESULTS: Patients with AIDS dementia complex had the largest number of defects (9.15 per patient) and healthy patients had the fewest defects (1.66 per patient). Patients with chronic fatigue syndrome and depression had similar numbers of defects per patient (6.53 and 6.43, respectively). In all groups, defects were located predominantly in the frontal and temporal lobes. The midcerebral uptake index was found to be significantly lower (p < .002) in the patients with chronic fatigue syndrome (.667) and patients with AIDS dementia complex (.650) than in patients with major depression (.731) or healthy control subjects (.716). Also, a significant negative correlation was found between the number of defects and midcerebral uptake index in patients with chronic fatigue syndrome and AIDS dementia complex, but not in depressed patients or control subjects.

CONCLUSION: These findings are consistent with the hypothesis that chronic fatigue syndrome may be due to a chronic viral encephalitis; clinical similarities between chronic fatigue syndrome and depression may be due to a similar distribution and number of defects in the two disorders.

 

Source: Schwartz RB, Komaroff AL, Garada BM, Gleit M, Doolittle TH, Bates DW, Vasile RG, Holman BL. SPECT imaging of the brain: comparison of findings in patients with chronic fatigue syndrome, AIDS dementia complex, and major unipolar depression. AJR Am J Roentgenol. 1994 Apr;162(4):943-51. http://www.ncbi.nlm.nih.gov/pubmed/8141022

 

Detection of intracranial abnormalities in patients with chronic fatigue syndrome: comparison of MR imaging and SPECT

Abstract:

OBJECTIVE: Chronic fatigue syndrome is a recently characterized condition of unknown origin that is manifested by fatigue, flulike complaints, and neurologic signs and symptoms, including persistent headache, impaired cognitive abilities, mood disorders, and sensorimotor disturbances. This syndrome can be difficult to diagnose clinically or by standard neuroradiologic tests. We performed MR imaging and single-photon emission computed tomography (SPECT) in patients with chronic fatigue syndrome to compare the usefulness of functional and anatomic imaging in the detection of intracranial abnormalities.

SUBJECTS AND METHODS: Sixteen patients who fulfilled the Centers for Disease Control, British, and/or Australian criteria for chronic fatigue syndrome had MR and SPECT examinations within a 10-week period. Axial MR and SPECT scans were analyzed as to the number and location of focal abnormalities by using analysis of variance with the Student-Newman-Keuls option. MR imaging findings in patients with chronic fatigue syndrome were compared with those in 15 age-matched control subjects, and SPECT findings in the patients with chronic fatigue syndrome were compared with those in 14 age-matched control subjects by using Fisher’s exact test. The findings on MR and SPECT scans in the same patients were compared by using the Wilcoxon matched-pairs signed-ranks test.

RESULTS: MR abnormalities consisted of foci of T2-bright signal in the periventricular and subcortical white matter and in the centrum semiovale; there were 2.06 foci per patient, vs 0.80 foci per control subject. MR abnormalities were present in eight (50%) of 16 patients, compared with three (20%) of 15 age-matched control subjects. Neither of these differences reached significance, although the power of the study to detect differences between groups was small. Patients with chronic fatigue syndrome had significantly more defects throughout the cerebral cortex on SPECT scans than did normal subjects (7.31 vs 0.43 defects per subject, p < .001). SPECT abnormalities were present in 13 (81%) of 16 patients, vs three (21%) of 14 control subjects (p < .01). SPECT scans showed significantly more abnormalities than did MR scans in patients with chronic fatigue syndrome (p < .025). In the few patients who had repeat SPECT and MR studies, the number of SPECT abnormalities appeared to correlate with clinical status, whereas MR changes were irreversible.

CONCLUSION: SPECT abnormalities occur more frequently and in greater numbers than MR abnormalities do in patients with chronic fatigue syndrome. SPECT may prove to be useful in following the clinical progress of patients with this syndrome.

 

Source: Schwartz RB, Garada BM, Komaroff AL, Tice HM, Gleit M, Jolesz FA, Holman BL. Detection of intracranial abnormalities in patients with chronic fatigue syndrome: comparison of MR imaging and SPECT. AJR Am J Roentgenol. 1994 Apr;162(4):935-41. http://www.ncbi.nlm.nih.gov/pubmed/8141020

 

A comparison of case definitions of chronic fatigue syndrome

Abstract:

We compared three case definitions of chronic fatigue syndrome (CFS) applied to patients followed in CFS clinics at two institutions. All patients had debilitating fatigue without apparent etiology; patients with medical conditions associated with chronic fatigue and with major psychiatric disorders were stratified and presented separately. Patients were classified according to whether they met case definitions developed by a Centers for Disease Control and Prevention (CDC) Working Group, a British group, or an Australian group. When findings for 805 patients followed at the two clinics were combined, 61% met the CDC criteria, 55% met the British criteria, and 56% met the Australian criteria; these proportions were relatively similar at both sites. In addition, similar laboratory abnormalities were found for all case groups and for fatigued patients who met none of the three case definitions. These data suggest that more inclusive case definitions may be superior.

 

Source: Bates DW, Buchwald D, Lee J, Kith P, Doolittle TH, Umali P, Komaroff AL. A comparison of case definitions of chronic fatigue syndrome. Clin Infect Dis. 1994 Jan;18 Suppl 1:S11-5. http://www.ncbi.nlm.nih.gov/pubmed/8148436

 

Prevalence of fatigue and chronic fatigue syndrome in a primary care practice

Abstract:

BACKGROUND: Our goals were to determine the prevalence of unusual, debilitating fatigue and the frequency with which it was associated with the chronic fatigue syndrome (CFS) or other physical or psychological illness in an outpatient clinic population.

METHODS: We prospectively evaluated a cohort of 1000 consecutive patients in a primary care clinic in an urban, hospital-based general medicine practice. The study protocol included a detailed history, physical examination, and laboratory and psychiatric testing.

RESULTS: Five patients who came because of CFS studies were excluded. Of the remaining 995, 323 reported fatigue, and 271 (27%) complained of at least 6 months of unusual fatigue that interfered with their daily lives. Of the 271, self-report or record review revealed a medical or psychiatric condition that could have explained the fatigue in 186 (69%). Thus, 85 (8.5%) of 995 patients had a debilitating fatigue of at least 6 months’ duration, without apparent cause. Of these patients, 48 refused further evaluation, and 11 were unavailable for follow-up; 26 completed the protocol. Three of the 26 were hypothyroid, and one had a major psychiatric disorder. Of the remaining 22 patients, three met Centers for Disease Control and Prevention criteria for CFS, four met British criteria, and 10 met the Australian case definition. The point prevalences of CFS were thus 0.3% (95% confidence interval [CI], 0% to 0.6%), 0.4% (95% CI, 0% to 0.8%), and 1.0% (95% CI, 0.4% to 1.6%) using the Centers for Disease Control and Prevention, British, and Australian case definitions, respectively. These estimates were conservative, because they assumed that none of the patients who refused evaluation or were unavailable for follow-up would meet criteria for CFS.

CONCLUSIONS: While chronic, debilitating fatigue is common in medical outpatients, CFS is relatively uncommon. Prevalence depends substantially on the case definition used.

 

Source: Bates DW, Schmitt W, Buchwald D, Ware NC, Lee J, Thoyer E, Kornish RJ, Komaroff AL. Prevalence of fatigue and chronic fatigue syndrome in a primary care practice. Arch Intern Med. 1993 Dec 27;153(24):2759-65. http://www.ncbi.nlm.nih.gov/pubmed/8257251

 

Clinical presentation of chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a chronic illness of uncertain aetiology characterized by at least six months of debilitating fatigue and associated symptoms. The symptoms of the syndrome are all non-specific and some (but not all) are also seen in psychiatric illness. The symptomatology suggesting an organic component to the illness includes its abrupt onset with an ‘infectious-like’ illness, intermittent unexplained fevers, arthralgias and ‘gelling’ (stiffness), sore throats, cough, photophobia, night sweats, and post-exertional malaise with systemic symptoms. The illness can last for years and is associated with marked impairment of functional health status.

 

Source: Komaroff AL. Clinical presentation of chronic fatigue syndrome. Ciba Found Symp. 1993;173:43-54; discussion 54-61. http://www.ncbi.nlm.nih.gov/pubmed/8491106

 

Human herpesvirus 7 is a T-lymphotropic virus and is related to, but significantly different from, human herpesvirus 6 and human cytomegalovirus

Abstract:

An independent strain (JI) of human herpesvirus 7 (HHV-7) was isolated from a patient with chronic fatigue syndrome (CFS). No significant association could be established by seroepidemiology between HHV-7 and CFS.

HHV-7 is a T-lymphotropic virus, infecting CD4+ and CD8+ primary lymphocytes. HHV-7 can also infect SUP-T1, an immature T-cell line, with variable success. Southern blot analysis with DNA probes scanning 58.8% of the human herpesvirus 6 (HHV-6) genome and hybridizing to all HHV-6 strains tested so far revealed homology to HHV-7 with only 37.4% of the total probe length. HHV-7 contains the GGGTTA repetitive sequence, as do HHV-6 and Marek’s disease chicken herpesvirus. DNA sequencing of a 186-base-pair fragment of HHV-7(JI) revealed an identity with HHV-6 and human cytomegalovirus of 57.5% and 36%, respectively. Oligonucleotide primers derived from this sequence (HV7/HV8, HV10/HV11) amplified HHV-7 DNA only and did not amplify DNA from other human herpesviruses, including 12 different HHV-6 strains. Southern blot analysis with the p43L3 probe containing the 186-base-pair HHV-7 DNA fragment hybridized to HHV-7 DNA only.

The molecular divergence between human cytomegalovirus, on the one hand, and HHV-6 and HHV-7, on the other, is greater than between HHV-6 and HHV-7, which, in turn, is greater than the difference between HHV-6 strains. This study supports the classification of HHV-7 as an additional member of the human beta-herpesviruses.

 

Source: Berneman ZN, Ablashi DV, Li G, Eger-Fletcher M, Reitz MS Jr, Hung CL, Brus I, Komaroff AL, Gallo RC. Human herpesvirus 7 is a T-lymphotropic virus and is related to, but significantly different from, human herpesvirus 6 and human cytomegalovirus. Proc Natl Acad Sci U S A. 1992 Nov 1;89(21):10552-6. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC50377/ (Full article)

 

NIH conference. Chronic fatigue syndrome research. Definition and medical outcome assessment

Abstract:

A workshop was held 18 to 19 March 1991 at the National Institutes of Health to address critical issues in research concerning the chronic fatigue syndrome (CFS). Case definition, confounding diagnoses, and medical outcome assessment by laboratory and other means were considered from the perspectives of key medical specialties involved in CFS research.

It was recommended that published Centers for Disease Control (CDC) case-definition criteria be modified to exclude fewer patients from analysis because of a history of psychiatric disorder. Specific recommendations were made concerning the inclusion or exclusion of other major confounding diagnoses, and a standard panel of laboratory tests was specified for initial patient evaluation.

The workshop emphasized the importance of recognizing other conditions that could explain the patient’s symptoms and that may be treatable. It was viewed as essential for the investigator to screen for psychiatric disorder using a combination of self-report instruments followed by at least one structured interview to identify patients who should be excluded from studies or considered as a separate subgroup in data analysis.

Because CFS is not a homogeneous abnormality and because there is no single pathogenic mechanism, research progress may depend upon delineation of these and other patient subgroups for separate data analysis. Despite preliminary data, no physical finding or laboratory test was deemed confirmatory of the diagnosis of CFS.

For assessment of clinical status, investigators must rely on the use of standardized instruments for patient self-reporting of fatigue, mood disturbance, functional status, sleep disorder, global well-being, and pain. Further research is needed to develop better instruments for quantifying these domains in patients with CFS.

 

Source: Schluederberg A, Straus SE, Peterson P, Blumenthal S, Komaroff AL, Spring SB, Landay A, Buchwald D. NIH conference. Chronic fatigue syndrome research. Definition and medical outcome assessment. Ann Intern Med. 1992 Aug 15;117(4):325-31. http://www.ncbi.nlm.nih.gov/pubmed/1322076

 

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

 

Review of laboratory findings for patients with chronic fatigue syndrome

Abstract:

Various abnormalities revealed by laboratory studies have been reported in adults with chronic fatigue syndrome. Those most consistently reported include depressed natural killer cell function and reduced numbers of natural killer cells; low levels of circulating immune complexes; low levels of several autoantibodies, particularly antinuclear antibodies and antithyroid antibodies; altered levels of immunoglobulins; abnormalities in number and function of lymphocytes; and modestly elevated levels of two Epstein-Barr virus-related antibodies, immunoglobulin G to viral capsid antigen and to early antigen.

 

Source: Buchwald D, Komaroff AL. Review of laboratory findings for patients with chronic fatigue syndrome. Rev Infect Dis. 1991 Jan-Feb;13 Suppl 1:S12-8. http://www.ncbi.nlm.nih.gov/pubmed/1902321