Comparison of heart rate variability in patients with chronic fatigue syndrome and controls

Abstract:

Recent studies have reported a close association between chronic fatigue syndrome and neurally mediated hypotension. We hypothesized that this association may result from an abnormality in autonomic function among patients with chronic fatigue syndrome, which may be detectable using an analysis of heart rate variability.

We prospectively studied 19 patients who fulfilled the Centers for Disease Control criteria for chronic fatigue syndrome and 11 controls. Each subject underwent a two-stage tilt-table test while wearing a Holter monitor. Heart rate variability was assessed in the supine baseline position and during upright tilt using frequency domain parameters.

In the baseline supine position, high frequency (HF) power, low frequency (LF) power, and the ratio of low frequency power to high frequency power (LF/HF ratio) were similar. In both patient groups, upright tilt resulted in a similar decrease in HF power, increase in LF power, and increase in the LH/HF ratio.

In conclusion, autonomic function, as assessed using an analysis of heart rate variability, does not differ in the baseline supine state, nor in response to upright tilt among patients with chronic fatigue syndrome and healthy controls.

 

Source: Yataco A, Talo H, Rowe P, Kass DA, Berger RD, Calkins H. Comparison of heart rate variability in patients with chronic fatigue syndrome and controls. Clin Auton Res. 1997 Dec;7(6):293-7. http://www.ncbi.nlm.nih.gov/pubmed/9430800

 

Chronic fatigue syndrome. Helping patients cope with this enigmatic illness

Abstract:

Chronic fatigue syndrome is a recurring, debilitating illness complicated by the fact that its diagnosis is largely based on subjective complaints and the absence of reproducibly reliable tests. There is no known “cure” for this illness; however, in general, the prognosis for patients is good. Some physicians accept the existence of chronic fatigue syndrome, while others are convinced that it exists only in the minds of its “victims.” The majority of physicians, however, are skeptical but open-minded and wish to help their chronically fatigued patients. As more information comes to light, it is likely that modern medicine will have to rethink its views on this elusive illness. In the interim, patients with chronic fatigue syndrome need the support and reassurance of their physicians to help them cope with their symptoms and resume normal, productive lives.

 

Source: Fuller NS, Morrison RE. Chronic fatigue syndrome. Helping patients cope with this enigmatic illness. Postgrad Med. 1998 Jan;103(1):175-6, 179-84. http://www.ncbi.nlm.nih.gov/pubmed/9448682

 

Physical activity in chronic fatigue syndrome: assessment and its role in fatigue

Abstract:

This paper describes the assessment of physical activity in chronic fatigue syndrome (CFS) and investigated the following questions: Do patients with CFS have low levels of physical activity; is there a relationship between actual level of physical activity and fatigue; can self-report measures adequately assess actual level of physical activity; what is the role of cognitions with respect to physical activity; and are results with respect to physical activity specific to CFS?

Three different types of activity measures were used: self-report questionnaires, a 12-day self-observation list, and a motion-sensing device (Actometer) which was used as a reference for actual activity level. Fifty-one patients with CFS, 50 fatigued patients with multiple sclerosis (MS), and 53 healthy subjects participated in this study.

Although none of the self-report questionnaires showed high correlations with the Actometer, questionnaires that require simple ratings of specified activities were related to the Actometer and can be used as acceptable substitutes, in contrast to instruments that require general subjective interpretations of activity that had low or non-significant correlations with the Actometer.

Actometer results showed that CFS patients and MS patients had similar activity levels and both groups were significantly less active than healthy subjects. Compared to MS patients, CFS patients were more likely to indicate that they had been less active than other persons they knew. Activities which patients expected to result in higher fatigue levels were less frequently performed. Patients with CFS had significantly higher scores on this measure than MS patients and healthy subjects. Low levels of physical activity were related to severe fatigue in CFS but not in MS.

In conclusion, although CFS patients have similar low activity levels than MS patients, there are also important differences between both groups: in CFS cognitive factors are more prominently involved in producing the low activity levels than in MS and in CFS patients activity level is related to fatigue but not in MS.

 

Source: Vercoulen JH, Bazelmans E, Swanink CM, Fennis JF, Galama JM, Jongen PJ, Hommes O, Van der Meer JW, Bleijenberg G. Physical activity in chronic fatigue syndrome: assessment and its role in fatigue. J Psychiatr Res. 1997 Nov-Dec;31(6):661-73. http://www.ncbi.nlm.nih.gov/pubmed/9447571

 

Salivary cortisol profiles in chronic fatigue syndrome

Abstract:

Salivary cortisol profiles (hourly sampling over a 16-hour period) of 10 patients with chronic fatigue syndrome (CFS) but without concurrent depressive disorder were compared with those of 10 healthy volunteers matched for age, sex and menstrual cycle. The mean saliva cortisol concentration over the 16-hour period was slightly but significantly greater in the patients than the controls (p < 0.05). These findings are at variance with earlier reports that CFS is a hypocortisolaemic state and suggest that in CFS the symptom of fatigue is not caused by hypocortisolaemia.

 

Source: Wood B, Wessely S, Papadopoulos A, Poon L, Checkley S. Salivary cortisol profiles in chronic fatigue syndrome. Neuropsychobiology. 1998;37(1):1-4. http://www.ncbi.nlm.nih.gov/pubmed/9438265

 

Elevated apoptotic cell population in patients with chronic fatigue syndrome: the pivotal role of protein kinase RNA

Abstract:

OBJECTIVES: A prominent feature of chronic fatigue syndrome (CFS) is a disordered immune system. Recent evidence indicates that induction of apoptosis might be mediated in a dysregulated immune system by the upregulation of growth inhibitory cytokines. Therefore, the purpose of this study was to evaluate the apoptotic cell population, interferon-alpha (IFN-alpha) and the IFN-induced protein kinase RNA (PKR) gene transcripts in peripheral blood lymphocytes (PBL) of CFS individuals, as compared to healthy controls.

SUBJECTS AND METHODS: PBL were isolated from CFS (n = 29) and healthy control individuals (n = 15) and subjected to quantitative analysis of apoptotic cell population and cell cycle progression by flow cytometry. Quantitative competitive polymerase chain reaction (Q/C PCR) and Western blot analysis were used to assess the levels of PKR mRNA and protein in control and CFS individuals. In addition, circulating IFN-alpha was measured by ELISA assay.

RESULTS: Increased apoptotic cell population was observed in CFS individuals, as compared to healthy controls (26.6 +/- 12.9% and 9.9 +/- 4.2%, respectively). The increased apoptotic subpopulation in CFS individuals was accompanied by an abnormal cell arrest in the S phase and the G2/M boundary of the cell cycle as compared to the control group (8.6 +/- 1.2 to 22.8 +/- 2.4 and 3.6 +/- 0.82 to 24.3 +/- 3.4, respectively). In addition, CFS individuals exhibited enhanced PKR mRNA and protein levels (mean basal level 3538 +/- 1050 and 2.7 +/- 0.26, respectively) as compared to healthy controls (mean basal level 562 +/- 162 and 0.89 +/- 0.18, respectively). In 50% of the CFS samples (n = 29) treated with 2-aminopurine (2-AP) (a potent inhibitor of PKR) the apoptotic population was reduced by more then 50%.

CONCLUSIONS: PKR-mediated apoptosis in CFS individuals may contribute to the pathogenesis and the fatigue symptomatology associated with CFS.

Comment in: Cortisol deficiency may account for elevated apoptotic cell population in patients with chronic fatigue syndrome. [J Intern Med. 1999]

 

Source: Vojdani A, Ghoneum M, Choppa PC, Magtoto L, Lapp CW. Elevated apoptotic cell population in patients with chronic fatigue syndrome: the pivotal role of protein kinase RNA. J Intern Med. 1997 Dec;242(6):465-78. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2796.1997.tb00019.x/epdf (Full article)

 

Do patients with “pure” chronic fatigue syndrome (neurasthenia) have abnormal sleep?

Abstract:

OBJECTIVE: To determine whether patients with “pure” chronic fatigue syndrome (neurasthenia) have sleep abnormalities which may contribute to subjective measures of daytime fatigue.

METHOD: Sleep characteristics of 20 patients meeting research criteria for chronic fatigue syndrome (CFS) but not depression, anxiety, or sleep disorder were compared with sleep characteristics of 20 healthy subjects matched for age and sex. Measures of sleep included a) subjective interview reports and sleep diaries and b) home-based polysomnography.

RESULTS: Patients with CFS complained of poor quality unrefreshing sleep. They also napped during the day. Polysomnograph data showed no difference in actual nocturnal sleep time between the two groups although patients with CFS spent significantly longer in bed (p < .01), slept less efficiently (p < .03), and spent longer awake after sleep onset (p < .05). The polysomnographs of seven patients with CFS and one healthy subject were regarded as significantly abnormal. Five patients and one healthy subject had difficulty maintaining sleep. One patient had a disorder of both initiating and maintaining sleep and one patient woke early.

CONCLUSIONS: Patients with “pure” CFS complain of unrefreshing sleep but only a minority have a clearly abnormal polysomnograph. The most common abnormality is of long periods spent awake after initial sleep onset. Although sleep abnormalities may play a role in the etiology of CFS, they seem to be unlikely to be an important cause of daytime fatigue in the majority of patients. However, pharmacological and behavioral methods that improve sleep quality may be an important component of a pragmatically based treatment package for patients who do have abnormal sleep.

 

Source: Sharpley A, Clements A, Hawton K, Sharpe M. Do patients with “pure” chronic fatigue syndrome (neurasthenia) have abnormal sleep? Psychosom Med. 1997 Nov-Dec;59(6):592-6. http://www.ncbi.nlm.nih.gov/pubmed/9407577

 

Adaptive tasks, coping and quality of life of chronically ill patients: the cases of Parkinson’s disease and chronic fatigue syndrome

Abstract:

This article is a report of a larger study on the relationship between adaptive tasks, coping and quality of life, taking Parkinson’s disease and chronic fatigue syndrome (CFS) as examples. The concept of adaptive tasks or disease-related stressors testing the adaptive capacities of chronically ill patients (N=134) was explored by applying the method of concept mapping.

Results show that patients both with Parkinson’s disease and with CFS generally refer to the same themes when asked for the adaptive tasks their disease brings about. However, the actual contents of these adaptive tasks differ as well as their impact on coping and quality of life. In the case of patients with Parkinson’s disease, objective disease characteristics appear to be more important in predicting quality of life than in the case of patients with CFS, whose evaluation of adaptive tasks is predictive of quality of life.

 

Source: De Ridder DT, Schreurs KM, Bensing JM. Adaptive tasks, coping and quality of life of chronically ill patients: the cases of Parkinson’s disease and chronic fatigue syndrome. J Health Psychol. 1998 Jan;3(1):87-101. Doi: 10.1177/135910539800300107. http://www.ncbi.nlm.nih.gov/pubmed/22021345

 

Outcomes of occupational stressors on nurses: chronic fatigue syndrome–related symptoms

Abstract:

Considering the types and number of occupational stressors involved in caring for patients, nurses may represent a population at high risk for physical illnesses.

A sample of 3400 nurses who belong to a statewide or a national nurses organization were randomly chosen for participation. Of this group, 202 reported 6 months or more of debilitating fatigue and completed a three-page questionnaire assessing symptoms related to chronic fatigue syndrome (CFS) and comorbid medical conditions. This group (N = 202) was mailed a follow-up questionnaire 1 year later that reassessed symptoms of CFS and occupational stressors.

Many sampled nurses reported a high degree of occupationally related stress but did not report CFS symptoms; however, perceived exposure to the threat of an accident as a nurse and poor physical working conditions were significantly related to symptoms reported. These findings are consistent with previous research.

 

Source: Wagner LI, Jason LA. Outcomes of occupational stressors on nurses: chronic fatigue syndrome–related symptoms. Nursingconnections. 1997 Fall;10(3):41-9. http://www.ncbi.nlm.nih.gov/pubmed/9397874

 

Demonstration on Borna disease virus in patients with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS), a recently named heterogeneous disorder, is an illness of unknown etiology. The association between CFS and several viral infection has been suggested. Here, we centered on the possible link between CFS and Borna disease virus (BDV) infection.

BDV is a neurotropic, nonsegmented negative-strand (NNS) RNA virus. Recent epidemiological data have suggested that BDV may be closely associated with depression and schizophrenia in humans.

In Japanese patients with CFS, the prevalence of BDV infection was 34% (30/89) and 12% (7/57) by immunoblotting and PCR analysis, respectively. Furthermore, anti-BDV antibodies and BDV RNA were detected in a family cluster with CFS. These results suggested that this virus contributes to or initiates CFS, although the single etiologic role of BDV is unlikely.

 

Source: Nakaya T, Kuratsune H, Kitani T, Ikuta K. Demonstration on Borna disease virus in patients with chronic fatigue syndrome. Nihon Rinsho. 1997 Nov;55(11):3064-71. [Article in Japanese] http://www.ncbi.nlm.nih.gov/pubmed/9396313

 

Cognitive deficits in patients suffering from chronic fatigue syndrome, acute infective illness or depression

Abstract:

BACKGROUND: Patients with chronic fatigue syndrome (CFS) report neuro-psychological symptoms as a characteristic feature. We sought to assess cognitive performance in patients with CFS, and compare cognitive performance and subjective workload experience of these patients with that of two disease comparison groups (non-melancholic depression and acute infection) and healthy controls.

METHOD: A computerized performance battery employed to assess cognitive functioning included tests of continuous attention, response speed, performance accuracy and memory. Severity of mood disturbance and subjective fatigue were assessed by questionnaire.

RESULTS: All patient groups demonstrated increased errors and slower reaction times, and gave higher workload ratings than healthy controls. Patients with CFS and non-melancholic depression had more severe deficits than patients with acute infection. All patient groups reported more severe mood disturbance and fatigue than healthy controls, but patients with CFS and those with acute infection reported less severe mood disturbance than patients with depression.

CONCLUSIONS: As all patients demonstrated similar deficits in attention and response speed, it is possible that common pathophysiological processes are involved. The differences in severity of mood disturbance, however, suggest that the pathophysiological processes in patients with CFS and acute infection are not simply secondary to depressed mood.

 

Source: Vollmer-Conna U, Wakefield D, Lloyd A, Hickie I, Lemon J, Bird KD, Westbrook RF. Cognitive deficits in patients suffering from chronic fatigue syndrome, acute infective illness or depression. Br J Psychiatry. 1997 Oct;171:377-81. http://www.ncbi.nlm.nih.gov/pubmed/9373430