A factor analysis of chronic fatigue symptoms in a community-based sample

Abstract:

BACKGROUND: This study examined characteristics of fatigue in individuals with chronic fatigue from a community-based study. Most studies of chronic fatigue have been based on patients recruited from primary or tertiary care settings. Samples such as these might not be representative of patients within the general population. The purpose of this study was to determine the factor structure of participants’ symptoms in a random community sample of individuals with chronic fatigue.

METHOD: A random sample of 18,675 respondents in Chicago received a brief telephone questionnaire designed to identify individuals with chronic fatigue. A group of 780 (4.2%) with chronic fatigue received further interview via telephone questionnaire involving characteristics of their fatigue. The analyses for this study were based on those people identified with having chronic fatigue. A factor analysis was conducted on responses to questionnaire items, and a four-factor solution emerged. Mean factor scores were derived and analyzed in relation to sociodemographic characteristics and sample subgroups.

RESULTS: The four factors were labeled: Lack of Energy, Physical Exertion, Cognitive Functioning, and Fatigue and Rest.

CONCLUSIONS: Results indicated that individuals with chronic fatigue have symptoms that can be differentiated into theoretically distinct factors.

 

Source: Jason LA, Taylor RR, Kennedy CL, Jordan K, Huang CF, Torres-Harding S, Song S, Johnson D. A factor analysis of chronic fatigue symptoms in a community-based sample.  Soc Psychiatry Psychiatr Epidemiol. 2002 Apr;37(4):183-9. http://www.ncbi.nlm.nih.gov/pubmed/12027245

 

Peripheral vestibular dysfunction in chronic fatigue syndrome

Abstract:

OBJECTIVE: To report left-sided peripheral vestibular failure as the cause of dizziness in a 12-year-old boy diagnosed as having chronic fatigue syndrome (CFS).

DESIGN: Retrospective case report with review of literature and discussion.

SETTING: Tertiary children’s hospital.

CONCLUSION: We recommend proper vestibular assessment for CFS patients presenting with dizziness, as effective treatment for peripheral vestibular disorder exists in the form of balance rehabilitation exercises.

 

Source: Palaniappan R, Sirimanna T. Peripheral vestibular dysfunction in chronic fatigue syndrome. Int J Pediatr Otorhinolaryngol. 2002 May 31;64(1):69-72. http://www.ncbi.nlm.nih.gov/pubmed/12020917

 

Impaired postural cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance

Abstract:

OBJECTIVES: To measure postural changes in cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance.

STUDY DESIGN: We studied 28 patients (age, 10 to 22 years) and 20 healthy control subjects (age, 6 to 27 years). Cerebral oxygenated hemoglobin (oxy-Hb) and deoxygenated Hb were noninvasively and continuously measured with near infrared spectroscopy during active standing. Beat-to-beat arterial pressure was monitored by Finapres.

RESULTS: Orthostatic intolerance determined by cardiovascular responses to standing was observed in 16 of 28 patients: instantaneous orthostatic hypotension in 8, delayed orthostatic hypotension in 2, and postural orthostatic tachycardia in 6. A rapid recovery of oxy-Hb by near infrared spectroscopy at the onset of active standing was not found in 15 of 16 patients with chronic fatigue and orthostatic intolerance and in 6 of 12 patients with chronic fatigue without orthostatic intolerance but only in 2 of 20 control subjects. Thirteen of 16 patients with orthostatic intolerance showed prolonged reduction in oxy-Hb during standing.

CONCLUSIONS: Impaired cerebral hemodynamics in patients with chronic fatigue syndrome and postural orthostatic tachycardia suggest a link between impaired cerebral oxygenation and chronic fatigue. However, this cannot explain the symptoms in patients meeting the criteria of chronic fatigue without orthostatic intolerance.

Comment in:

Chronic fatigue syndrome and Addison’s disease. [J Pediatr. 2003]

Orthostatic intolerance and chronic fatigue syndrome: new light on an old problem. [J Pediatr. 2002]

 

Source: Tanaka H, Matsushima R, Tamai H, Kajimoto Y. Impaired postural cerebral hemodynamics in young patients with chronic fatigue with and without orthostatic intolerance. J Pediatr. 2002 Apr;140(4):412-7. http://www.ncbi.nlm.nih.gov/pubmed/12006954

 

Mediators of inflammation and their interaction with sleep: relevance for chronic fatigue syndrome and related conditions

Abstract:

In humans, activation of the primary host defense system leads to increased or decreased NREM sleep quality, depending on the degree of early immune activation. Modest elevations of certain inflammatory cytokines are found during experimental sleep loss in humans and, in addition, relatively small elevations of cytokines are seen following commencement of pharmacological treatments with clozapine, a CNS active antipsychotic agent, known to have immunomodulatory properties. Cytokines such as TNF-alpha, its soluble receptors, and IL-6, present in the periphery and the CNS, comprise a link between peripheral immune stimulation and CNS-mediated behaviors and experiences such as sleep, sleepiness, and fatigue. The debilitating fatigue experienced in chronic fatigue syndrome and related diseases may also be related to altered cytokine profiles.

 

Source: Mullington JM, Hinze-Selch D, Pollmächer T. Mediators of inflammation and their interaction with sleep: relevance for chronic fatigue syndrome and related conditions.  Ann N Y Acad Sci. 2001 Mar;933:201-10. http://www.ncbi.nlm.nih.gov/pubmed/12000021

 

Dry eyes and mouth syndrome–a subgroup of patients presenting with sicca symptoms

Abstract:

OBJECTIVE: To evaluate the characteristics of patients presenting with symptoms suggestive of Sjögren’s syndrome (SS) but failing to satisfy diagnostic criteria.

METHODS: Clinical, serological and histological data were collected on 34 patients presenting with dry eyes and/or mouth who did not satisfy the Vitali criteria for the diagnosis of SS. They were compared with 136 patients with primary SS, 38 patients with secondary SS, and 13 patients without SS. Questionnaires on symptoms from each group were compared with 43 healthy controls.

RESULTS: The 34 patients who did not satisfy the diagnostic criteria for SS or any other connective tissue disease were designated dry eyes and mouth syndrome (DEMS). Their demography including age was similar to that of a primary SS group and there was no more atrophy seen on their biopsies compared with SS and non-SS controls. They scored highly on visual analogue scales of symptoms but had few objective signs. All were negative for anti-Ro and anti-La although the prevalence of antinuclear antibodies (19%) was increased compared with a normal population. There was no excess of SS-associated tissue types.

CONCLUSION: There was no evidence that age, salivary gland atrophy or subclinical SS accounted for the symptoms in DEMS. Most of the patients fitted into a spectrum of disease which tended more towards fibromyalgia and/or chronic fatigue syndrome.

Comment in: Dry eyes and mouth syndrome or sicca, asthenia and polyalgia syndrome? [Rheumatology (Oxford). 2003]

 

Source: Price EJ, Venables PJ. Dry eyes and mouth syndrome–a subgroup of patients presenting with sicca symptoms. Rheumatology (Oxford). 2002 Apr;41(4):416-22. http://rheumatology.oxfordjournals.org/content/41/4/416.long (Full article)

 

 

 

Symptom occurrence in persons with chronic fatigue syndrome

Abstract:

This investigation compared differences in the occurrence of symptoms in participants with CFS, melancholic depression, and no fatigue (controls). The following Fukuda et al. [Ann. Intern. Med. 121 (1994) 953] criteria symptoms differentiated the CFS group from controls, but did not differentiate the melancholic depression group from controls: headaches, lymph node pain, sore throat, joint pain, and muscle pain. In addition, participants with CFS uniquely differed from controls in the occurrence of muscle weakness at multiple sites as well as in the occurrence of various cardiopulmonary, neurological, and other symptoms not currently included in the current case definition. Implications of these findings are discussed.

 

Source: Jason LA, Torres-Harding SR, Carrico AW, Taylor RR. Symptom occurrence in persons with chronic fatigue syndrome. Biol Psychol. 2002 Feb;59(1):15-27. http://www.ncbi.nlm.nih.gov/pubmed/11790441

 

Interpretation of symptoms in chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is an illness characterised by fatigue and other symptoms. Both psychological and biological aetiological factors have been proposed, but the disorder is of uncertain origin. The aetiology of the symptoms is therefore ambiguous. It has been suggested (a) that patients with CFS tend to interpret their symptoms as indicating physical illness and (b) they tend not to interpret these symptoms in terms of negative emotion.

In order to test these hypotheses we developed a self-report questionnaire to assess the interpretation of symptoms in patients with CFS. It was administered to patients with CFS, patients with depression, patients with multiple sclerosis (MS), and normal controls. Preliminary results suggest that the measure has acceptable psychometric properties.

Patients with CFS were more likely than either depressed patients or normal controls to interpret symptoms (characteristic of CFS) in terms of physical illness, but did not differ in this from the MS patients. When compared with all three other groups (including the MS patients), the patients with CFS were least likely to interpret symptoms in terms of negative emotional states. The theoretical and clinical implications of the findings are discussed.

 

Source: Dendy C, Cooper M, Sharpe M. Interpretation of symptoms in chronic fatigue syndrome. Behav Res Ther. 2001 Nov;39(11):1369-80. http://www.ncbi.nlm.nih.gov/pubmed/11686271

 

How significant are primary sleep disorders and sleepiness in the chronic fatigue syndrome?

Abstract:

In order to study both the prevalence of Primary Sleep Disorders (PSD) and sleepiness, and their association to the Chronic Fatigue Syndrome (CFS), 46 unselected outpatients (34 women, mean age 36.5) were examined clinically and underwent two nights of all-night polysomnography and multiple sleep latency tests (MSLT).

Forty-six percent presented with a Sleep Apnea/Hypopnea Syndrome Index (AHI>=5), 5% with a Periodic Limb Movements syndrome. No subject received a diagnosis of Narcolepsy or Idiopathic Hypersomnia. Thirty percent showed the presence of objective sleepiness as measured by MSLT<10 minutes. Objective and subjective measures of sleepiness were not associated with CFS, nor with the double diagnosis of CFS and a PSD. The presence of PSD or sleepiness was not associated with any of the clinical scales that were used to measure anxiety, depression, somatisation, physical or mental fatigue, or functional status impairment.

Fifty-four percent of CFS patients had no PSD, and 69% no sleepiness. These patients could not be distinguished clinically from patients having a PSD or from those with sleepiness. Therefore, it is unlikely that CFS is simply a somatic expression of any PSD observed in our sample or of sleepiness per se.

 

Source: Le Bon O, Fischler B, Hoffmann G, Murphy JR, De Meirleir K, Cluydts R, Pelc I. How significant are primary sleep disorders and sleepiness in the chronic fatigue syndrome? Sleep Res Online. 2000;3(2):43-8. http://www.ncbi.nlm.nih.gov/pubmed/11382899

 

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

 

Sleep and circadian rhythm disorders in fibromyalgia

Abstract:

Fibromyalgia (FM) is a syndrome of generalized muscle pain that is also associated with equally distressing symptoms of sleep disturbance and fatigue. FM shows clinical overlap with other stress-associated disorders, including chronic fatigue syndrome (CFS) and depression. All of these conditions have the features of disrupted sleep patterns and dysregulated biologic circadian rhythms, such as stress hormone secretion. This review focuses on the role of sleep and circadian rhythm disorders in FM and, in the absence of any specific treatment for FM, presents a pragmatic therapeutic approach aimed at identifying and treating comorbid sleep and depressive disorders, optimizing sleep habits, and judicious use of pharmacologic agents.

 

Source: Korszun A. Sleep and circadian rhythm disorders in fibromyalgia. Curr Rheumatol Rep. 2000 Apr;2(2):124-30. http://www.ncbi.nlm.nih.gov/pubmed/11123049