Increased illness experience preceding chronic fatigue syndrome: a case control study

Abstract:

BACKGROUND: Almost all published work on chronic fatigue syndrome (CFS) has involved retrospective surveys of cases, which may introduce recall bias. Only medical records collected before diagnosis of CFS can eliminate this.

METHODS: Using data collected several years prior to the development of the illness, we performed a case control study, comparing the reported illness records of all people who subsequently made an insurance claim as a result of CFS, with those of future multiple sclerosis (MS) claimants, and those of non-claimant controls (NC).

RESULTS: The study encompassed 133 CFS, 75 MS and 162 NC cases. CFS cases had recorded significantly more illnesses at time of proposal for insurance than the two control groups, and had significantly more claims between proposal and diagnosis of their disorder. Almost all disease categories were reported higher in future CFS sufferers, lethargy having the highest odds ratio after adjustment in a multivariate model.

INTERPRETATION: The results of this paper on CFS patients who claim permanent health insurance do not support a specific viral or immunological explanation for CFS. We conclude that abnormal illness behaviour is of greater importance than previously recognised.

Comment in:

Increased illness experience preceding chronic fatigue syndrome. [J R Coll Physicians Lond. 1998]

Increased illness experience preceding chronic fatigue syndrome. [J R Coll Physicians Lond. 1998]

 

Source: Hall GH, Hamilton WT, Round AP. Increased illness experience preceding chronic fatigue syndrome: a case control study. J R Coll Physicians Lond. 1998 Jan-Feb;32(1):44-8. http://www.ncbi.nlm.nih.gov/pubmed/9507441

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

 

Chronic fatigue syndrome–aetiological aspects

Abstract:

The chronic fatigue syndrome (CFS) has been intensively studied over the last 40 years, but no conclusions have yet been agreed as to its cause. Most cases nowadays are sporadic. In the established chronic condition there are no consistently abnormal physical signs or abnormalities on laboratory investigation.

Many physicians remain convinced that the symptoms are psychological rather than physical in origin. This view is reinforced by the emotional way in which many patients present themselves. The overlap of symptoms between CFS and depression remains a source of confusion and difficulty. But even if all CFS patients were rediagnosed as depressives, this would not negate the possibility of an underlying organic cause for the condition, in view of the growing evidence that depression itself has a physical cause and responds best to physical treatments.

There is some evidence both for active viral infection and for an immunological disorder in the CFS. Many observations suggest that the syndrome could derive from residual damage to the reticular activating system (RAS) of the upper brain stem and/or to its cortical projections. Such damage could be produced by a previous viral infection, leaving functional defects unaccompanied by any gross histological changes.

In animal experiments activation of the RAS can change sleep state and activate or stimulate cortical functions. RAS lesions can produce somnolence and apathy. Studies by modern imaging techniques have not been entirely consistent, but many magnetic resonance imaging (MRI) studies already suggest that small discrete patchy brain stem and subcortical lesions can often be seen in CFS.

Regional blood flow studies by single photon-emission computerized tomography (SPECT) have been more consistent. They have revealed blood flow reductions in many regions, especially in the hind brain. Similar lesions have been reported after poliomyelitis and in multiple sclerosis–in both of which conditions chronic fatigue is characteristically present. In the well-known post-polio fatigue syndrome, lesions predominate in the RAS of the brain stem. If similar underlying lesions in the RAS can eventually be identified in CFS, the therapeutic target for CFS would be better defined than it is at present. A number of logical approaches to treatment can already be envisaged.

Comment in:

Chronic fatigue syndrome. [Eur J Clin Invest. 1997]

Similarity of symptoms in chronic fatigue syndrome and Addison’s disease. [Eur J Clin Invest. 1997]

 

Source: Dickinson CJ. Chronic fatigue syndrome–aetiological aspects. Eur J Clin Invest. 1997 Apr;27(4):257-67. http://www.ncbi.nlm.nih.gov/pubmed/9134372

 

The effects of fatigue on neuropsychological performance in patients with chronic fatigue syndrome, multiple sclerosis, and depression

Abstract:

The effects of fatigue on neuropsychological performance were examined in patients with fatiguing illnesses. Repeated testing with the Paced Auditory Serial Addition Test (PASAT; Gronwall, 1977) was employed over the course of a demanding neuropsychological testing session. It was hypothesized that if fatigue affects performance, one would expect to observe “blunting” of the PASAT practice effect.

Fifteen of the study participants live with chronic fatigue syndrome (CFS), 15 with multiple sclerosis (MS), 14 with depression (DEP), and 15 are healthy, sedentary controls. Overall PASAT performance was significantly reduced for CFS and DEP participants compared to controls, whereas mean performance did not differ across the three fatiguing illness groups. Degree of improvement across trials (i.e., practice effect) for the groups did not differ from controls’. Neither subjective fatigue or DEP were significantly related to PASAT performance.

These findings suggest that fatigue does not universally impair performance during neuropsychological assessment even in groups in which fatigue is a prominent symptom.

 

Source: Johnson SK, Lange G, DeLuca J, Korn LR, Natelson B. The effects of fatigue on neuropsychological performance in patients with chronic fatigue syndrome, multiple sclerosis, and depression. Appl Neuropsychol. 1997;4(3):145-53. http://www.ncbi.nlm.nih.gov/pubmed/16318477

 

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

 

Selective impairment of auditory processing in chronic fatigue syndrome: a comparison with multiple sclerosis and healthy controls

Abstract:

The most consistent deficit observed in individuals with Chronic Fatigue Syndrome has been in efficiency of information processing. To examine the possibility of a modality-specific impairment, the present study examined subjects with Chronic Fatigue Syndrome, multiple sclerosis, and healthy controls on an auditory-versus visual-paced serial-addition test. 20 subjects with Chronic Fatigue Syndrome, 20 subjects with clinically definite Multiple Sclerosis, and 20 sedentary healthy controls were compared.

One-half of the subjects in each group were administered the Paced Auditory Serial Addition Test and the other half were administered the Paced Visual Serial Addition Test. The group with Chronic Fatigue Syndrome was differentially impaired on the auditory relative to the visual processing task. The group with Multiple Sclerosis was equally impaired on both versions of the task. The results are discussed within the framework of Baddeley’s model of working memory.

 

Source: Johnson SK, DeLuca J, Diamond BJ, Natelson BH. Selective impairment of auditory processing in chronic fatigue syndrome: a comparison with multiple sclerosis and healthy controls. Percept Mot Skills. 1996 Aug;83(1):51-62. http://www.ncbi.nlm.nih.gov/pubmed/8873173

 

The measurement of fatigue in patients with multiple sclerosis. A multidimensional comparison with patients with chronic fatigue syndrome and healthy subjects

Abstract:

OBJECTIVE: To provide a multidimensional characterization of fatigue in patients with multiple sclerosis (MS).

DESIGN: Cross-sectional design. Fifty patients with clinically definite MS were compared on the dimensions of fatigue with 51 patients with chronic fatigue syndrome (CFS) and 53 healthy subjects.

RESULTS: Fourty-six percent of the patients with MS reported fatigue to be present at least once a week. Patients with MS and patients with CFS had significantly higher subjective fatigue severity scores than healthy subjects. Patients with MS and patients with CFS had significantly higher scores on measures of psychological well-being than healthy subjects. Patients with MS had scores similar to those of patients with CFS, except that patients with CFS had significantly higher somatization scores. High somatization scores reflect strong focusing on bodily sensations. Both groups of patients were significantly less active than the healthy subjects. The Kurtzke Expanded Disability Status Scale (EDSS) and the Beck Depression Inventory scores were not related to subjective fatigue severity. In patients with MS and in patients with CFS, subjective fatigue severity was related to impairment in daily life, low sense of control over symptoms, and strong focusing on bodily sensations. In CFS, but not in MS, evidence was found for a relationship between low levels of physical activity and attributing symptoms to a physical cause and between subjective fatigue severity and physical activity.

CONCLUSIONS: Patients with MS experienced significant fatigue, which had a significant impact on daily functioning and was not related to depression on Expanded Disability Status Scale score. Psychological factors, such as focusing on bodily sensations and low sense of control play a role in the experience of fatigue in MS and CFS.

 

Source: Vercoulen JH, Hommes OR, Swanink CM, Jongen PJ, Fennis JF, Galama JM, van der Meer JW, Bleijenberg G. The measurement of fatigue in patients with multiple sclerosis. A multidimensional comparison with patients with chronic fatigue syndrome and healthy subjects. Arch Neurol. 1996 Jul;53(7):642-9. http://www.ncbi.nlm.nih.gov/pubmed/8929171

 

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

 

Personality dimensions in the chronic fatigue syndrome: a comparison with multiple sclerosis and depression

Abstract:

This study investigated the relative rates of personality disturbance in chronic fatigue syndrome (CFS). Individuals who met the CDC criteria for CFS were compared to two other fatiguing illness groups, mild multiple sclerosis and depression, as well as sedentary healthy controls.

Subjects were administered a structured psychiatric interview to determine Axis I psychiatric disorders and two self-report instruments to assess Axis II personality disorders and the personality trait of neuroticism.

The depressed group had significantly more personality disorders and elevated neuroticism scores compared with the other three groups. The CFS and MS subjects had intermediary personality scores which were significantly higher than healthy controls.

The CFS group with concurrent depressive disorder (34% of the CFS group) was found to account for most of the personality pathology in the CFS sample. The results are discussed in the context of the relationship between personality variables and fatiguing illness.

 

Source: Johnson SK, DeLuca J, Natelson BH. Personality dimensions in the chronic fatigue syndrome: a comparison with multiple sclerosis and depression. J Psychiatr Res. 1996 Jan-Feb;30(1):9-20. http://www.ncbi.nlm.nih.gov/pubmed/8736462

 

Assessing somatization disorder in the chronic fatigue syndrome

Abstract:

This study was conducted to examine the rates of somatization disorder (SD) in the chronic fatigue syndrome (CFS) relative to other fatiguing illness groups. It further addressed the arbitrary nature of the judgments made in assigning psychiatric vs. physical etiology to symptoms in controversial illnesses such as CFS.

Patients with CFS (N = 42), multiple sclerosis (MS) (N = 18), and depression (N = 21) were compared with healthy individuals (N = 32) on a structured psychiatric interview. The SD section of the Diagnostic Interview Schedule (DIS) III-R was reanalyzed using different criteria sets to diagnose SD. All subjects received a thorough medical history, physical examination, and DIS interview. CFS patients received diagnostic laboratory testing to rule out other causes of fatigue.

This study revealed that changing the attribution of SD symptoms from psychiatric to physical dramatically affected the rates of diagnosing SD in the CFS group. Both the CFS and depressed subjects endorsed a higher percentage of SD symptoms than either the MS or healthy groups, but very few met the strict DSM-III-R criteria for SD. The present study illustrates that the terminology used to interpret the symptoms (ie, psychiatric or physical) will determine which category CFS falls into. The diagnosis of SD is of limited use in populations in which the etiology of the illness has not been established.

 

Source: Johnson SK, DeLuca J, Natelson BH. Assessing somatization disorder in the chronic fatigue syndrome. Psychosom Med. 1996 Jan-Feb;58(1):50-7. http://www.ncbi.nlm.nih.gov/pubmed/8677289