The effect of exercise on gait and balance in patients with chronic fatigue syndrome

Abstract:

This study investigated anecdotal reports of gait and balance abnormalities in subjects with Chronic Fatigue Syndrome (CFS) by examining the effects of a light exercise test on postural sway and various gait parameters. Tests were performed on 11 CFS patients and 11 age- and sex-matched sedentary controls. Results demonstrated that postural sway was not significantly different in both groups before or after the exercise test. There were, however, significant differences in gait parameters between the two groups confirming anecdotal evidence, but these differences were not exacerbated by the exercise test. Heart rate responses demonstrated that both groups were exercising at similar loads, although this was perceived to be higher by the CFS group.

 

Source: Paul LM, Wood L, Maclaren W. Gait Posture. 2001 Jul;14(1):19-27. The effect of exercise on gait and balance in patients with chronic fatigue syndrome. Gait Posture. 2001 Jul;14(1):19-27. http://www.ncbi.nlm.nih.gov/pubmed/11378421

 

Monozygotic twins discordant for chronic fatigue syndrome: regional cerebral blood flow SPECT

Abstract:

PURPOSE: To evaluate the relationship between regional cerebral blood flow (rCBF) and chronic fatigue syndrome (CFS) in monozygotic twins discordant for CFS.

MATERIALS AND METHODS: The authors conducted a co-twin control study of 22 monozygotic twins in which one twin met criteria for CFS and the other was healthy. Twins underwent a structured psychiatric interview and resting technetium 99m-hexamethyl-propyleneamine oxime single photon emission computed tomography of the brain. They also rated their mental status before the procedure. Scans were interpreted independently by two physicians blinded to illness status and then at a blinded consensus reading. Imaging fusion software with automated three-dimensional matching of rCBF images was used to coregister and quantify results. Outcomes were the number and distribution of abnormalities at both reader consensus and automated quantification. Mean rCBF levels were compared by using random effects regression models to account for the effects of twin matching and potential confounding factors.

RESULTS: The twins with and those without CFS were similar in mean number of visually detected abnormalities and in mean differences quantified by using image registration software. These results were unaltered with adjustments for fitness level, depression, and mood before imaging.

CONCLUSION: The study results did not provide evidence of a distinctive pattern of resting rCBF abnormalities associated with CFS. The described method highlights the importance of selecting well-matched control subjects.

 

Source: Lewis DH, Mayberg HS, Fischer ME, Goldberg J, Ashton S, Graham MM, Buchwald D. Monozygotic twins discordant for chronic fatigue syndrome: regional cerebral blood flow SPECT. Radiology. 2001 Jun;219(3):766-73. http://www.ncbi.nlm.nih.gov/pubmed/11376266

 

Thirteen-year follow-up of children and adolescents with chronic fatigue syndrome

Abstract:

OBJECTIVE: To describe the educational, social, and symptomatic outcome of children and adolescents with chronic fatigue syndrome 13 years after illness onset.

METHODS: Between January 1984 and December 1987, 46 children and adolescents developed an illness suggestive of chronic fatigue syndrome. Follow-up questionnaires were obtained from 35 participants an average of 13 years after illness onset. Data were obtained concerning subsequent medical diagnoses, amount of school missed, presence and severity of current symptoms, and subjective assessment of degree of illness resolution.

RESULTS: Of the 35 participants, 24 were female (68.6%) and 11 were male (31.4%). Average age at illness onset was 12.1 years. Eight participants (22.9%) had an acute onset of symptoms, 27 (77.1%) had a gradual onset. No participant received an alternative medical diagnosis that could have explained the symptom complex between illness onset and follow-up. Thirteen participants (37.1%) considered themselves resolved of illness at follow-up; 15 participants (42.9%) considered themselves well but not resolved; 4 (11.4%) considered themselves chronically ill; and 3 (8.6%) considered themselves more ill than during the early years of illness. Correlation with the Medical Outcomes Study Short Form Health Survey was good for current level of symptoms and degree of recovery. Eight participants (22.9%) missed >2 years of school, and 5 of these were still ill at follow-up. Amount of school missed correlated with both illness severity at follow-up and perceived social impact of the illness.

CONCLUSIONS: These data demonstrate the presence of an illness consistent with the current definition of chronic fatigue syndrome. Eighty percent of children and adolescents affected had a satisfactory outcome from their fatiguing illness, although the majority of these participants had mild to moderate persisting symptoms. Twenty percent of participants remain ill with significant symptoms and activity limitation 13 years after illness onset. Chronic fatigue syndrome in children and adolescents may result in persistent somatic symptoms and disability in a minority of those affected.

 

Source: Bell DS, Jordan K, Robinson M. Thirteen-year follow-up of children and adolescents with chronic fatigue syndrome. Pediatrics. 2001 May;107(5):994-8. http://www.ncbi.nlm.nih.gov/pubmed/11331676

 

Patients’ perceptions of medical care in chronic fatigue syndrome

Abstract:

This study investigated perceptions of medical care among patients with chronic fatigue syndrome (CFS) referred to a specialist clinic. Sixty-eight patients completed a questionnaire survey on their overall satisfaction with medical care received since the onset of their illness, and their views on specific aspects of care.

Two-thirds of patients were dissatisfied with the quality of medical care received. Dissatisfied patients were significantly more likely to describe delay, dispute or confusion over diagnosis; to have received and rejected a psychiatric diagnosis; to perceive doctors as dismissive, skeptical or not knowledgeable about CFS and to feel that the advice given was inadequate or conflicting.

Satisfied patients were significantly more likely to perceive doctors as caring, supportive and interested in their illness; to state that they did not expect their doctors to cure CFS and to perceive their GP or hospital doctor as the source of greatest help during their illness. Many patients were critical of the paucity of treatment, but this was not associated with overall satisfaction.

The findings suggest that medical care was evaluated less on the ability of doctors to treat CFS, and more on their interpersonal and informational skills. Dissatisfaction with these factors is likely to impede the development of a therapeutic doctor-patient alliance, which is central to the effective management of CFS. The findings suggest a need for better communication and better education of doctors in the diagnosis and management of CFS.

 

Source: Deale A, Wessely S. Patients’ perceptions of medical care in chronic fatigue syndrome. Soc Sci Med. 2001 Jun;52(12):1859-64. http://www.ncbi.nlm.nih.gov/pubmed/11352411

 

Decreased tryptophan availability but normal post-synaptic 5-HT2c receptor sensitivity in chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) has been associated with increased prolactin (PRL) responses to the serotonin (5-HT) releasing agent fenfluramine. It is not known whether this abnormality is due to increased 5-HT release or heightened sensitivity of post-synaptic 5-HT receptors.

METHODS: We measured the increase in plasma PRL produced by the directly acting 5-HT receptor agonist, m-chlorophenylpiperazine (mCPP), in patients with CFS and healthy controls. We also compared the ability of mCPP to lower slow wave sleep (SWS) in the sleep polysomnogram of both subject groups. Finally, we measured plasma amino-acid levels to determine whether tryptophan availability differed between CFS subjects and controls.

RESULTS: mCPP elevated plasma PRL equivalently in patients with CFS and controls. Similarly, the decrease in SWS produced by mCPP did not differ between the two subject groups. Plasma-free tryptophan was significantly decreased in CFS.

CONCLUSIONS: The sensitivity of post-synaptic 5-HT2c receptors is not increased in patients with CFS. This suggests that the increased PRL response to fenfluramine in CFS is due to elevated activity of pre-synaptic 5-HT neurones. This change is unlikely to be due to increased peripheral availability of tryptophan.

 

Source: Vassallo CM, Feldman E, Peto T, Castell L, Sharpley AL, Cowen PJ. Decreased tryptophan availability but normal post-synaptic 5-HT2c receptor sensitivity in chronic fatigue syndrome. Psychol Med. 2001 May;31(4):585-91. http://www.ncbi.nlm.nih.gov/pubmed/11352361

 

A review of the evidence for overlap among unexplained clinical conditions

Abstract:

PURPOSE: Unexplained clinical conditions share features, including symptoms (fatigue, pain), disability out of proportion to physical examination findings, inconsistent demonstration of laboratory abnormalities, and an association with “stress” and psychosocial factors. This literature review examines the nature and extent of the overlap among these unexplained clinical conditions and the limitations of previous research.

DATA SOURCES: English-language articles were identified by a search of the MEDLINE database from 1966 to January 2001 by using individual syndromes and their hallmark symptoms as search terms.

STUDY SELECTION: Studies that assessed patients with at least one unexplained clinical condition and that included information on symptoms, overlap with other unexplained clinical conditions, or physiologic markers. Conditions examined were the chronic fatigue syndrome, fibromyalgia, the irritable bowel syndrome, multiple chemical sensitivity, temporomandibular disorder, tension headache, interstitial cystitis, and the postconcussion syndrome.

DATA EXTRACTION: Information on authorship, patient and control groups, eligibility criteria, case definitions, study methods, and major findings.

DATA SYNTHESIS: Many similarities were apparent in case definition and symptoms, and the proportion of patients with one unexplained clinical condition meeting criteria for a second unexplained condition was striking. Tender points on physical examination and decreased pain threshold and tolerance were the most frequent and consistent objective findings. A major shortcoming of all proposed explanatory models is their inability to account for the occurrence of unexplained clinical conditions in many affected patients.

CONCLUSIONS: Overlap between unexplained clinical conditions is substantial. Most studies are limited by methodologic problems, such as case definition and the selection and recruitment of case-patients and controls.

 

Source: Aaron LA, Buchwald D. A review of the evidence for overlap among unexplained clinical conditions. Ann Intern Med. 2001 May 1;134(9 Pt 2):868-81. http://www.ncbi.nlm.nih.gov/pubmed/11346323

 

Chronic fatigue: symptom and syndrome

Abstract:

Chronic fatigue is common, is difficult to measure, can be associated with considerable morbidity, and is rarely a subject of controversy. The chronic fatigue syndrome also presents problems in definition and measurement, is associated with even more morbidity than chronic fatigue itself, and is often controversial. Particularly unclear is the way in which chronic fatigue and the chronic fatigue syndrome relate to each other: Is one the severe form of the other, or are they qualitatively and quantitatively different? We know that many things can cause chronic fatigue, and this is probably true for the chronic fatigue syndrome, too. We can anticipate that discrete causes of the chronic fatigue syndrome will be found in the future, even if these causes are unlikely to fall neatly along the physical-psychological divide that some expect. The causes of chronic fatigue are undoubtedly many, both in a population and in any individual person, even when a discrete cause, such as depression or cancer, is identified. Social, behavioral, and psychological variables are important in both chronic fatigue and the chronic fatigue syndrome. Interventions that address these general variables can be successful, and currently they are often more successful than interventions directed at specific causes.

 

Source: Wessely S. Chronic fatigue: symptom and syndrome. Ann Intern Med. 2001 May 1;134(9 Pt 2):838-43. http://www.ncbi.nlm.nih.gov/pubmed/11346319

 

A small, randomized, placebo-controlled trial of the use of antiviral therapy for patients with chronic fatigue syndrome

Comment on: Editorial response: microbial persistence and idiopathic dilated cardiomyopathy. [Clin Infect Dis. 1999]

 

SIR—We have presented controlled and observational data that are consistent with the hypothesis that subsets of cases of chronic fatigue syndrome (CFS) result from cardiac disease due to a single, persisting infection caused by Epstein-Barr virus (EBV) or, in turn, to a single, persisting infection caused by human cytomegalovirus (HCMV) in immunocompetent patients [1]. Patients who have a separate subset of CFS have simultaneous coinfection with EBV and HCMV. Cardiomyopathic changes are observed in right ventricular endomyocardial biopsy specimens obtained from such patients, and abnormal findings on Holter monitoring (e.g., oscillating abnormal T-wave flattenings and T-wave inversions) are “uniformly” present [2–4]. Left ventricular dysfunction is manifested by sinus tachycardia at rest, abnormal cardiac-wall motion, and decreased left ventricular ejection fractions (rest/stress) in those patients with CFS who are most ill [5]. These findings belie the relatively normal findings observed on standard 12-lead electrocardiograms [6].

In January 1995, a double-blinded, placebo-controlled, phase III crossover study of patients with CFS was initiated. Eleven patients who had CFS (10 of whom were women) were each followed for 18 consecutive months. The mean patient age was 42.7 years, and the mean duration of CFS was 35.1 months. Before antiviral nucleosides were administered, endomyocardial biopsies were performed. Cardiac tissues and blood samples tested negative for isolation of HCMV in cultures of human fibroblast tissues. Two cardiac biopsy specimens that were obtained from patients who had CFS tested positive for HCMV nucleic acids by means of PCR. No cardiac specimen that was obtained from a patient with CFS tested positive for EBV nucleic acids. (Cardiac tissue samples that were obtained from 4 of 21 control patients who had coronary artery disease but who did not have CFS also tested positive for HCMV nucleic acids.) Cardiomyopathic degenerative findings (e.g., myofiber disarray, interstitial fibrosis, increased intracellular granules, and interstitial fat) were noted in patients who had CFS. One patient who had CFS had myocarditis with focal lymphocytic infiltrates.

You can read the rest of this article here: http://cid.oxfordjournals.org/content/32/11/1657.long

 

Source: Lerner AM, Zervos M, Chang CH, Beqaj S, Goldstein J, O’Neill W, Dworkin H, Fitgerald T, Deeter RG. A small, randomized, placebo-controlled trial of the use of antiviral therapy for patients with chronic fatigue syndrome. Clin Infect Dis. 2001 Jun 1;32(11):1657-8. http://cid.oxfordjournals.org/content/32/11/1657.long (Full article)

 

Detection of immunologically significant factors for chronic fatigue syndrome using neural-network classifiers

Abstract:

Neural-network classifiers were used to detect immunological differences in groups of chronic fatigue syndrome (CFS) patients that heretofore had not shown significant differences from controls. In the past linear methods were unable to detect differences between CFS groups and non-CFS control groups in the nonveteran population.

An examination of the cluster structure for 29 immunological factors revealed a complex, nonlinear decision surface. Multilayer neural networks showed an over 16% improvement in an n-fold resampling generalization test on unseen data. A sensitivity analysis of the network found differences between groups that are consistent with the hypothesis that CFS symptoms are a consequence of immune system dysregulation.

Corresponding decreases in the CD19(+) B-cell compartment and the CD34(+) hematopoietic progenitor subpopulation were also detected by the neural network, consistent with the T-cell expansion. Of significant interest was the fact that, of all the cytokines evaluated, the only one to be in the final model was interleukin-4 (IL-4). Seeing an increase in IL-4 suggests a shift to a type 2 cytokine pattern. Such a shift has been hypothesized, but until now convincing evidence to support that hypothesis has been lacking.

 

Source: Hanson SJ, Gause W, Natelson B. Detection of immunologically significant factors for chronic fatigue syndrome using neural-network classifiers. Clin Diagn Lab Immunol. 2001 May;8(3):658-62. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC96120/ (Full article)

 

Relationship of brain MRI abnormalities and physical functional status in chronic fatigue syndrome

Abstract:

Chronic Fatigue Syndrome (CFS) is an unexplained illness that is characterized by severe fatigue. Some have suggested that CFS is a “functional somatic syndrome” in which symptoms of fatigue are inappropriately attributed to a serious illness. However, brain magnetic resonance imaging (MRI) data suggest that there may be an organic abnormality associated with CFS.

To understand further the significance of brain MRI abnormalities, we examined the relationship between MRI identified brain abnormalities and self-reported physical functional status in 48 subjects with CFS who underwent brain MR imaging and completed the Medical Outcomes Study SF-36. Brain MR images were examined for the presence of abnormalities based on 5 general categories previously shown to be sensitive to differentiating CFS patients from healthy controls.

There were significant negative relationships between the presence of brain abnormalities and both the physical functioning (PF) (rho=-.31, p=.03), and physical component summary PCS (rho=-.32, p=.03) subscales of the SF-36. CFS patients with MRI identified brain abnormalities scored significantly lower on both PF (t(1,46) =2.3, p=.026) and the PCS (t(1,41) =2.4, p=.02) than CFS subjects without an identified brain abnormality. When adjusted for age differences only the PF analysis remained significant. However, the effect sizes for both analyses were large indicating meaningful differences in perceived functional status between the groups.

These results demonstrate that the presence of brain abnormalities in CFS are significantly related to subjective reports of physical function and that CFS subjects with MRI brain abnormalities report being more physically impaired than those patients without brain abnormalities.

 

Source: Cook DB, Lange G, DeLuca J, Natelson BH. Relationship of brain MRI abnormalities and physical functional status in chronic fatigue syndrome. Int J Neurosci. 2001 Mar;107(1-2):1-6. http://www.ncbi.nlm.nih.gov/pubmed/11328679