Tag: review

Evidence for and pathophysiologic implications of hypothalamic-pituitary-adrenal axis dysregulation in fibromyalgia and chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is characterized by profound fatigue and an array of diffuse somatic symptoms.

Our group has established that impaired activation of the hypothalamic-pituitary-adrenal (HPA) axis is an essential neuroendocrine feature of this condition. The relevance of this finding to the pathophysiology of CFS is supported by the observation that the onset and course of this illness is excerbated by physical and emotional stressors. It is also notable that this HPA dysregulation differs from that seen in melancholic depression, but shares features with other clinical syndromes (e.g., fibromyalgia).

How the HPA axis dysfunction develops is unclear, though recent work suggests disturbances in serotonergic neurotransmission and alterations in the activity of AVP, an important co-secretagogue that, along with CRH, influences HPA axis function.

In order to provide a more refined view of the nature of the HPA disturbance in patients with CFS, we have studied the detailed, pulsatile characteristics of the HPA axis in a group of patients meeting the 1994 CDC case criteria for CFS. Results of that work are consistent with the view that patients with CFS have a reduction of HPA axis activity due, in part, to impaired central nervous system drive. These observations provide an important clue to the development of more effective treatment to this disabling condition.

 

Source: Demitrack MA, Crofford LJ. Evidence for and pathophysiologic implications of hypothalamic-pituitary-adrenal axis dysregulation in fibromyalgia and chronic fatigue syndrome. Ann N Y Acad Sci. 1998 May 1;840:684-97. http://www.ncbi.nlm.nih.gov/pubmed/9629295

 

No strong evidence of disturbed regulation of blood pressure in chronic fatigue syndrome

Abstract:

Recent medical publications postulate a connection between the Chronic Fatigue Syndrome (CFS) and disturbed regulation of the circulation, manifesting itself during orthostatic stress testing.

Four studies were published on the circulatory response on prolonged head up tilt testing. Numerous CFS patients displayed postural tachycardia or syncope during the test. However, many CFS patients examined had had orthostatic symptoms prior to the examination.

It is not certain that cardiovascular dysregulation is present in CFS patients without orthostatic symptoms. It is also not clear whether such a dysregulation would be the effect of physical inactivity or a manifestation of a subtle form of autonomic neuropathy.

 

Source: Smit AA, Bolweg NM, Lenders JW, Wieling W. No strong evidence of disturbed regulation of blood pressure in chronic fatigue syndrome. Ned Tijdschr Geneeskd. 1998 Mar 21;142(12):625-8.[Article in Dutch] http://www.ncbi.nlm.nih.gov/pubmed/9623125

 

Chronic fatigue syndrome: a review for clinicians

Abstract:

Syndromes characterized by persistent fatigue, musculoskeletal pain, sleep disturbance, and subjective cognitive impairment have been common problems in clinical practice for decades. The chronic fatigue syndrome case definition was created to standardize the patient population in research studies and to foster a systematic and comprehensive approach to the attempt to define the etiology and pathophysiology of these syndromes. The pathogenesis of chronic fatigue syndrome remains unknown, though it does appear to be associated with subtle neuroendocrine and immunologic abnormalities. Treatment of chronic fatigue syndrome is empirical. Significant palliation is often possible, though treatment success requires skillful practice of the art of medicine.

 

Source: Goshorn RK. Chronic fatigue syndrome: a review for clinicians. Semin Neurol. 1998;18(2):237-42. http://www.ncbi.nlm.nih.gov/pubmed/9608620

 

The connection between chronic fatigue syndrome and neurally mediated hypotension

Abstract:

Research from several groups of investigators indicates that some patients with chronic fatigue syndrome have abnormal vasovagal or vasodepressor responses to upright posture. If confirmed, these findings may explain some of the symptoms of chronic fatigue syndrome. There is also speculation that neurally mediated hypotension may be present in fibromyalgia. This article discusses the original research in this area, the results of follow-up studies, and the current approach to treating patients with chronic fatigue syndrome in whom neurally mediated hypotension is suspected.

 

Source: Wilke WS, Fouad-Tarazi FM, Cash JM, Calabrese LH. The connection between chronic fatigue syndrome and neurally mediated hypotension. Cleve Clin J Med. 1998 May;65(5):261-6. http://www.ncbi.nlm.nih.gov/pubmed/9599909

 

Fibromyalgia, chronic fatigue syndrome, and myofascial pain

Abstract:

Epidemiologic studies continue to provide evidence that fibromyalgia is part of a spectrum of chronic widespread pain. The prevalence of chronic widespread pain is several times higher than fibromyalgia as defined by the 1990 American College of Rheumatology guidelines. There is now compelling evidence of a familial clustering of fibromyalgia cases in female sufferers; whether this clustering results from nature or nature remains to be elucidated. A wide spectrum of fibromyalgia-associated symptomatology and syndromes continues to be described.

During the past year the association with interstitial cystitis has been explored, and neurally mediated hypotension has been documented in both fibromyalgia and chronic fatigue syndrome. Abnormalities of the growth hormone-insulin-like growth factor-1 axis have been also documented in both fibromyalgia and chronic fatigue syndrome. The commonly reported but anecdotal association of fibromyalgia with whiplash-type neck trauma was validated in a report from Israel. However, unlike North America, 100% of Israeli patients with posttraumatic fibromyalgia returned to work.

Basic research in fibromyalgia continues to pinpoint abnormal sensory processing as being integral to understanding fibromyalgia pain. Drugs such as ketamine, which block N-methyl-D-aspartate receptors (which are often upregulated in central pain states) were shown to benefit fibromyalgia pain in an experimental setting. The combination of fluoxetine and amitriptyline was reported to be more beneficial than either drug alone in patients with fibromyalgia.

A high prevalence of autoantibodies to cytoskeletal and nuclear envelope proteins was found in chronic fatigue syndrome, and an increased prevalence of antipolymer antibodies was found in symptomatic silicone breast implant recipients who often have fibromyalgia.

 

Source: Bennett R. Fibromyalgia, chronic fatigue syndrome, and myofascial pain. Curr Opin Rheumatol. 1998 Mar;10(2):95-103. http://www.ncbi.nlm.nih.gov/pubmed/9567202

 

Chronic fatigue syndrome: a literature review from a physiatric perspective

Abstract:

To examine the literature on chronic fatigue syndrome (CFS), especially as it relates to cognitive deficits and exercise, more than 200 articles related to CFS were selected from computer-based research as well as pertinent articles noted in the references of individual articles. All were relevant articles on CFS, although articles in a foreign language were excluded. CFS is a controversial diagnosis of exclusion, but certain subgroups do appear to exist. It may represent multiple diseases or multiple stages of the same disease. Although cognitive deficits are commonly reported, the measured impairments are relatively subtle and are in the area of complex information processing speed, or efficiency.

Magnetic resonance imaging, single-photon emission computer tomography, and neuroendocrine studies present preliminary evidence suggestive of the cerebral involvement primarily in the white matter. The weakness and fatigue may be the result of alterations in the central nervous system, not in the peripheral muscles. However, it is hard to separate the documented weakness and endurance deficits from deconditioning.

Autonomic symptoms such as orthostatic intolerance and a predisposition to neurally mediated syncope may be explained by cardiovascular deconditioning, a postviral idiopathic autonomic neuropathy, or both. The review points out the need for more carefully designed studies of CFS that focus on the relationship between neuropathology, psychopathology and neuropsychologic functioning. The role of exercise as a stimulus for exacerbation or in treatment needs to be further studied using clear diagnostic criteria as well as control groups that carefully match the activity level.

 

Source: Jain SS, DeLisa JA. Chronic fatigue syndrome: a literature review from a physiatric perspective. Am J Phys Med Rehabil. 1998 Mar-Apr;77(2):160-7. http://www.ncbi.nlm.nih.gov/pubmed/9558019

 

Chronic fatigue syndrome: an update

Abstract:

Among the many patients who seek medical care for the complaint of fatigue, a small number suffer from chronic fatigue syndrome (CFS). CFS is a poorly understood condition characterized by debilitating fatigue and associated symptoms lasting at least six months. Studies indicate that the illness is not simply a manifestation of an underlying psychiatric disorder, but rather is an illness characterized by activation of the immune system, various abnormalities of several hypothalamic-pituitary axes, and reactivation of certain infectious agents.

 

Source: Komaroff AL, Buchwald DS. Chronic fatigue syndrome: an update. Annu Rev Med. 1998;49:1-13. http://www.ncbi.nlm.nih.gov/pubmed/9509246

 

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

 

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

 

Politics, science, and the emergence of a new disease. The case of chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) emerged as a diagnostic category during the last decade. Initial research suggested that CFS was a relatively rare disorder with a high level of psychiatric comorbidity. Many physicians minimized the seriousness of this disorder and also interpreted the syndrome as being equivalent to a psychiatric disorder. These attitudes had negative consequences for the treatment of CFS.

By the mid-1990s, findings from more representative epidemiological studies indicated considerably higher CFS prevalence rates. However, the use of the revised CFS case definition might have produced heterogeneous patient groups, possibly including some patients with pure psychiatric disorders.

Social scientists have the expertise to more precisely define this syndrome and to develop appropriate and sensitive research strategies for understanding this disease.

Comment in: The biopsychosocial model and chronic fatigue syndrome. [Am Psychol. 1998]

 

Source: Jason LA, Richman JA, Friedberg F, Wagner L, Taylor R, Jordan KM. Politics, science, and the emergence of a new disease. The case of chronic fatigue syndrome. Am Psychol. 1997 Sep;52(9):973-83. http://www.ncbi.nlm.nih.gov/pubmed/9301342