Does the chronic fatigue syndrome involve the autonomic nervous system?

Abstract:

PURPOSE: To investigate the role of the autonomic nervous system in the symptoms of patients with chronic fatigue syndrome (CFS) and delineate the pathogenesis of the orthostatic Intolerance and predisposition to neurally mediated syncope reported in this patient group.

PATIENTS AND METHODS: Twenty-three CFS patients and controls performed a battery of autonomic function tests. The CFS patients completed questionnaires pertaining to autonomic and CFS symptoms, their level of physical activity, and premorbid and coexisting psychiatric disorders. The relationship between autonomic test results, cardiovascular deconditioning, and psychiatric disorders was examined with multivariate statistics and the evidence that autonomic changes seen in CFS might be secondary to a postviral, idiopathic autonomic neuropathy was explored.

RESULTS: The CFS subjects had a significant increase in baseline (P < 0.01) and maximum heart rate (HR) on standing and tilting (both P < 0.0001). Tests of parasympathetic nervous system function (the expiratory inspiratory ratio, P < 0.005; maximum minus minimum HR difference, P < 0.05), were significantly less in the CFS group as were measures of sympathetic nervous system function (systolic blood pressure decrease with tilting, P < 0.01; diastolic blood pressure decrease with tilting, P < 0.05; and the systolic blood pressure decrease during phase II of a Valsalva maneuver, P < 0.05). Twenty-five percent of CFS subjects had a positive tilt table test. The physical activity index was a significant predictor of autonomic test results (resting, sitting, standing, and tilted HR, P < 0.05 to P < 0.009); and the blood pressure decrease in phase II of the Valvalsa maneuver, P < 0.05) whereas premorbid and coexistent psychiatric conditions were not. The onset of autonomic symptoms occurred within 4 weeks of a viral infection in 46% of patients-a temporal pattern that is consistent with a postviral, idiopathic autonomic neuropathy.

CONCLUSION: Patients with CFS show alterations in measures of sympathetic and parasympathetic nervous system function. These results, which provide the physiological basis for the orthostatic intolerance and other symptoms of autonomic function in this patient group, may be explained by cardiovascular deconditioning, a postviral idiopathic autonomic neuropathy, or both.

 

Source: Freeman R, Komaroff AL. Does the chronic fatigue syndrome involve the autonomic nervous system? Am J Med. 1997 Apr;102(4):357-64. http://www.ncbi.nlm.nih.gov/pubmed/9217617

 

Elevation of bioactive transforming growth factor-beta in serum from patients with chronic fatigue syndrome

Abstract:

The level of bioactive transforming growth factor-beta (TGF-beta) was measured in serum from patients with chronic fatigue syndrome (CFS), healthy control subjects, and patients with major depression, systemic lupus erythematosis (SLE), and multiple sclerosis (MS) of both the relapsing/remitting (R/R) and the chronic progressive (CP) types.

Patients with CFS had significantly higher levels of bioactive TGF-beta levels compared to the healthy control major depression, SLE, R/R MS, and CP MS groups (P < 0.01). Additionally, no significant differences were found between the healthy control subjects and any of the disease comparison groups.

The current finding that TGF-beta is significantly elevated among patients with CFS supports the findings of two previous studies examining smaller numbers of CFS patients.

In conclusion, TGF-beta levels were significantly higher in CFS patients compared to patients with various diseases known to be associated with immunologic abnormalities and/or pathologic fatigue. These findings raise interesting questions about the possible role of TGF-beta in the pathogenesis of CFS.

 

Source: Bennett AL, Chao CC, Hu S, Buchwald D, Fagioli LR, Schur PH, Peterson PK, Komaroff AL. Elevation of bioactive transforming growth factor-beta in serum from patients with chronic fatigue syndrome. J Clin Immunol. 1997 Mar;17(2):160-6. http://www.ncbi.nlm.nih.gov/pubmed/9083892

 

Somatomedin C (insulin-like growth factor I) levels in patients with chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome is a disorder clinically quite similar to fibromyalgia syndrome, and it is of interest to examine if these two syndromes have pathogenetic as well as clinical features in common. Somatomedin C levels have been found to be lower in patients with fibromyalgia syndrome than in healthy controls. An attractive hypothesis relating sleep disturbance, altered somatotropic neuroendocrine function and fibromyalgia symptoms has been put forward as a plausible pathogenic mechanism for fibromyalgia syndrome. We therefore sought to investigate the level of somatomedin C in patients with chronic fatigue syndrome.

Somatomedin C levels were determined by radioimmunoassay in frozen serum specimens from 49 patients with CFS and 30 healthy blood donor control subjects of similar age and gender. Somatomedin C levels were higher in patients with CFS than in healthy control subjects (255.3 +/- 68.5 vs 211.9 +/- 76.2, P = 0.01). There was no effect of gender, use of nonsteroidal anti-inflammatory drugs or tricyclic drugs on levels of somatomedin C. There was a tendency for somatomedin C levels to fall with age.

In contrast to patients with fibromyalgia, in whom levels of somatomedin C have been found to be reduced, levels in patients with CFS were found to be elevated. Thus, despite the clinical similarities between these two conditions, they may be associated with different abnormalities of sleep and/or of the somatotropic neuroendocrine axis.

 

Source: Bennett AL, Mayes DM, Fagioli LR, Guerriero R, Komaroff AL. Somatomedin C (insulin-like growth factor I) levels in patients with chronic fatigue syndrome. J Psychiatr Res. 1997 Jan-Feb;31(1):91-6. http://www.ncbi.nlm.nih.gov/pubmed/9201651

 

Immunoglobulin subclass levels in chronic fatigue syndrome

Abstract:

The levels of immunoglobulin subclasses were determined for 46 patients meeting the original Centers for Disease Control case definition of chronic fatigue syndrome and were compared to values obtained for 50 age- and gender-matched healthy volunteer blood donor controls. The levels of immunoglobulin subclasses in these groups were further compared to a third group of additional chronic fatigue syndrome cases from whom samples had been obtained and frozen prospectively over a period of 7 years. These data do not demonstrate significant immunoglobulin subclass deficiencies in patients with chronic fatigue syndrome.

 

Source: Bennett AL, Fagioli LR, Schur PH, Schacterle RS, Komaroff AL. Immunoglobulin subclass levels in chronic fatigue syndrome. J Clin Immunol. 1996 Nov;16(6):315-20. http://www.ncbi.nlm.nih.gov/pubmed/8946275

 

Cognitive deficits in patients with chronic fatigue syndrome

Abstract:

Twenty-nine subjects with chronic fatigue syndrome (CFS) and 25 healthy control subjects were administered a lengthy neuropsychological battery that included standard neuropsychological tests and a computerized set of tasks that spanned the same areas of ability.

The primary significant differences between patients and controls were found on tests of learning and memory. These differences remained when the degree of psychiatric symptomatology in the subjects was covaried. Patients on and off psychoactive medications did not differ in their performance on these tasks.

These results suggest that at least a subset of CFS patients may experience significant impairments in learning and memory.

 

Source: Marcel B, Komaroff AL, Fagioli LR, Kornish RJ 2nd, Albert MS. Cognitive deficits in patients with chronic fatigue syndrome. Biol Psychiatry. 1996 Sep 15;40(6):535-41. http://www.ncbi.nlm.nih.gov/pubmed/8879474

 

Viral serologies in patients with chronic fatigue and chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is an illness characterized by disabling fatigue associated with complaints of fevers, sore throat, myalgia, lymphadenopathy, sleep disturbances, neurocognitive difficulties, and depression. A striking feature of CFS is its sudden onset following an acute, presumably viral, illness and the subsequent recurrent “flu-like” symptoms. It has been speculated that both CFS and debilitating chronic fatigue (CF) that does not meet strict criteria for CFS may be the direct or indirect result of viral infections.

We therefore tested 548 chronically fatigued patients who underwent a comprehensive medical and psychiatric evaluation for antibodies to 13 viruses. Our objectives were to compare the seroprevalence and/or geometric mean titer (GMT) of antibodies to herpes simplex virus 1 and 2, rubella, adenovirus, human herpesvirus 6, Epstein-Barr virus, cytomegalovirus, and Cox-sackie B virus, types 1-6 in patients with CF to healthy control subjects. Other goals were to determine if greater rates of seropositivity or higher GMTs occurred among subsets of patients with CFS, fibromyalgia, psychiatric disorders, a self-reported illness onset with a viral syndrome, and a documented temperature > 37 degrees C on physical examination.

Differences in the seroprevalence or GMTs of antibodies to 13 viruses were not consistently found in those with CF compared with control subjects, or in any subsets of patients including those with CFS, an acute onset of illness, or a documented fever. These particular viral serologies were not useful in evaluating patients presenting with CF.

 

Source: Buchwald D, Ashley RL, Pearlman T, Kith P, Komaroff AL. Viral serologies in patients with chronic fatigue and chronic fatigue syndrome. J Med Virol. 1996 Sep;50(1):25-30. http://www.ncbi.nlm.nih.gov/pubmed/8890037

 

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

 

An examination of the working case definition of chronic fatigue syndrome

Abstract:

PURPOSE: Chronic fatigue syndrome (CFS) currently is defined by a working case definition developed under the leadership of the United States Centers for Disease Control and Prevention (CDC) based on a consensus among experienced clinicians. We analyzed the experience from one large center to examine the adequacy of the case definition.

PATIENTS AND METHODS: Predefined clinical and laboratory data were collected prospectively from 369 patients with debilitating fatigue, of whom 281 (76%) met the major criteria of the original CDC case definition for CFS: (1) fatigue of at least 6 months’ duration, seriously interfering with the patient’s life; and (2) without evidence of various organic or psychiatric illnesses that can produce chronic fatigue. The same clinical data were obtained from 311 healthy control subjects and two comparison groups with diseases that can present in a similar fashion; relapsing-remitting multiple sclerosis (n = 25) and major depression (n = 19).

RESULTS: All of the minor criteria symptoms from the original CDC case definition distinguished patients with debilitating chronic fatigue from healthy control subjects, and many distinguished the patients with chronic fatigue from the comparison groups with multiple sclerosis and depression: myalgias, postexertional malaise, headaches, and a group of infectious-type symptoms (ie, chronic fever and chills, sore throat, swollen glands in the neck or underarm areas). In addition, two other symptoms not currently part of the case definition discriminated the chronic fatigue patients from the control/comparison groups: anorexia and nausea. Physical examination criteria only infrequently contributed to the diagnosis. Patients meeting the CDC major criteria for CFS also met the minor criteria in 91% of cases.

CONCLUSION: Patients meeting the major criteria of the current CDC working case definition of CFS reported symptoms that were clearly distinguishable from the experience of healthy control subjects and from disease comparison groups with multiple sclerosis and depression. Eliminating three symptoms (ie, muscle weakness, arthralgias, and sleep disturbance) and adding two others (ie, anorexia and nausea) would appear to strengthen the CDC case definition of CFS.

 

Source: Komaroff AL, Fagioli LR, Geiger AM, Doolittle TH, Lee J, Kornish RJ, Gleit MA, Guerriero RT. An examination of the working case definition of chronic fatigue syndrome. Am J Med. 1996 Jan;100(1):56-64. http://www.ncbi.nlm.nih.gov/pubmed/8579088

 

Prevalence of IgM antibodies to human herpesvirus 6 early antigen (p41/38) in patients with chronic fatigue syndrome

Erratum in: J Infect Dis 1995 Dec;172(6):1643.

 

Abstract:

To evaluate the association between human herpesvirus 6 (HHV-6) and chronic fatigue syndrome (CFS), 2 geographically separate groups of CFS patients (125 and 29 patients, respectively) and healthy controls (150 and 15 controls, respectively) were compared, using an EIA, for antibodies to HHV-6 early antigen p41/38 (EA).

Sixty percent (93/154) of CFS patients were were positive for HHV-6 EA IgM, 40% (61/154) were positive for IgG, and 23% (35/154) were positive for both. A total of 119 (77%) of the CFS patients were positive for HHV-6 EA IgG or IgM (or both); only 12% (20/165) of the controls had IgG or IgM to HHV-6 EA. These data demonstrate that more CFS patients than controls had elevated levels of HHV-6 EA-specific IgM, perhaps indicating active replication of HHV-6 in CFS.

 

Source: Patnaik M, Komaroff AL, Conley E, Ojo-Amaize EA, Peter JB. Prevalence of IgM antibodies to human herpesvirus 6 early antigen (p41/38) in patients with chronic fatigue syndrome. J Infect Dis. 1995 Nov;172(5):1364-7. http://www.ncbi.nlm.nih.gov/pubmed/7594679

 

Chronic fatigue and the chronic fatigue syndrome: prevalence in a Pacific Northwest health care system

Abstract:

OBJECTIVES: To investigate the point prevalence of the chronic fatigue syndrome and unexplained debilitating chronic fatigue in a community-based sample of persons and to describe demographic, clinical, and psychosocial differences among those with the chronic fatigue syndrome, those with chronic fatigue, and healthy controls.

DESIGN: Prospective cohort study.

SETTING: A health maintenance organization in Seattle, Washington.

PARTICIPANTS: A random sample of 4000 members of the health maintenance organization was surveyed by mail for the presence of chronic fatigue.

MEASUREMENTS: Persons with chronic fatigue were evaluated using a questionnaire that requested information about medical history and fatigue and related symptoms; validated measures of functional status and psychological distress; a physical examination; and standardized blood tests. A structured psychiatric interview was done in persons who appeared to meet the original Centers for Disease Control and Prevention (CDC) criteria for the chronic fatigue syndrome. Participants completed self-report measures at 12 and 24 months. Those with chronic fatigue were reevaluated in person 1 year after study enrollment.

RESULTS: 3066 (77%) of the 4000 members surveyed responded. Chronic fatigue was reported by 590 persons (19%). Of these, 388 (66%) had a medical or psychiatric condition that could account for the fatigue. Of the 74 persons (37%) with chronic fatigue who were enrolled in the study, only 3 met the CDC criteria for the chronic fatigue syndrome. The remaining 71 persons were designated as having chronic fatigue alone. Seventy-four healthy, age- and sex-matched controls who were drawn from the same sample but who denied having chronic fatigue were also studied. Demographic characteristics were similar in persons with the chronic fatigue syndrome, persons with chronic fatigue alone, and controls. Those with the chronic fatigue syndrome or chronic fatigue alone had more frequent cervical and axillary adenopathy, poorer functional status, and greater psychological distress than controls. Women and minorities were not overrepresented among cases with chronic fatigue.

CONCLUSIONS: Using different assumptions about the likelihood that persons who did not participate in the study had the chronic fatigue syndrome, the estimated crude point prevalence of the syndrome in this community ranged from 75 to 267 cases per 100,000 persons. The point prevalence of chronic fatigue alone was strikingly higher; it ranged from 1775 to 6321 cases per 100,000 persons.

 

Source: Buchwald D, Umali P, Umali J, Kith P, Pearlman T, Komaroff AL. Chronic fatigue and the chronic fatigue syndrome: prevalence in a Pacific Northwest health care system. Ann Intern Med. 1995 Jul 15;123(2):81-8. http://www.ncbi.nlm.nih.gov/pubmed/7778839