Tag: review

High-resolution magnetic resonance imaging sinc-interpolation-based subvoxel registration and semi-automated quantitative lateral ventricular morphology employing threshold computation and binary image creation in the study of fatty acid interventions in schizophrenia, depression, chronic fatigue syndrome and Huntington’s disease

Abstract:

Serial high-resolution structural magnetic resonance imaging scans of the brain can now be precisely aligned, with six degrees of freedom (three mutually orthogonal translational and three rotational degrees of freedom around three mutually orthogonal axes), using a rigid-body subvoxel registration technique. This is driven by the in-plane point spread function for images acquired in the Fourier domain with data obtained over a bounded region of k-space, namely the sinc interpolation function, where sinc z = (sin z)/z, with z being any complex number (including zero).

Computational subtraction of the three-dimensional Cartesian spatial representation matrices of serially acquired scan data allows for the determination of structural cerebral changes with great precision, since voxel signals from unchanged structures are almost completely cancelled. Thus changes readily show up against a background of noise. Furthermore, lateral ventricular changes can now be accurately quantified using a semi-automated method involving contour production, threshold computation, binary image creation and ventricular extraction.

These techniques have been applied to the investigation of the effects on cerebral structure of intervention with fatty acids, particularly the long-chain polyunsaturated n-3 fatty acid eicosapentaenoic acid (EPA), in disorders such as schizophrenia, treatment-resistant depression, chronic fatigue syndrome (myalgic encephalomyelitis or ME), and Huntington’s disease.

 

Source: Puri BK. High-resolution magnetic resonance imaging sinc-interpolation-based subvoxel registration and semi-automated quantitative lateral ventricular morphology employing threshold computation and binary image creation in the study of fatty acid interventions in schizophrenia, depression, chronic fatigue syndrome and Huntington’s disease. Int Rev Psychiatry. 2006 Apr;18(2):149-54. https://www.ncbi.nlm.nih.gov/pubmed/16777669

Patterns of hypocapnia on tilt in patients with fibromyalgia, chronic fatigue syndrome, nonspecific dizziness, and neurally mediated syncope

Abstract:

OBJECTIVES: To assess whether head-up tilt-induced hyperventilation is seen more often in patients with chronic fatigue syndrome (CFS), fibromyalgia, dizziness, or neurally mediated syncope (NMS) as compared to healthy subjects or those with familial Mediterranean fever (FMF).

PATIENTS AND METHODS: A total of 585 patients were assessed with a 10-minute supine, 30-minute head-up tilt test combined with capnography. Experimental groups included CFS (n = 90), non-CFS fatigue (n = 50), fibromyalgia (n = 70), nonspecific dizziness (n = 75), and NMS (n =160); control groups were FMF (n = 90) and healthy (n = 50). Hypocapnia, the objective measure of hyperventilation, was diagnosed when end-tidal pressure of CO2 (PETCO2) less than 30 mm Hg was recorded consecutively for 10 minutes or longer. When tilting was discontinued because of syncope, one PETCO2 measurement of 25 or less was accepted as hyperventilation.

RESULTS: Hypocapnia was diagnosed on tilt test in 9% to 27% of patients with fibromyalgia, CFS, dizziness, and NMS versus 0% to 2% of control subjects. Three patterns of hypocapnia were recognized: supine hypocapnia (n = 14), sustained hypocapnia on tilt (n = 76), and mixed hypotensive-hypocapnic events (n = 80). Hypocapnia associated with postural tachycardia syndrome (POTS) occurred in 8 of 41 patients.

CONCLUSIONS: Hyperventilation appears to be the major abnormal response to postural challenge in sustained hypocapnia but possibly merely an epiphenomenon in hypotensive-hypocapnic events. Our study does not support an essential role for hypocapnia in NMS or in postural symptoms associated with POTS. Because unrecognized hypocapnia is common in CFS, fibromyalgia, and nonspecific dizziness, capnography should be a part of the evaluation of patients with such conditions.

 

Source: Naschitz JE, Mussafia-Priselac R, Kovalev Y, Zaigraykin N, Slobodin G, Elias N, Rosner I. Patterns of hypocapnia on tilt in patients with fibromyalgia, chronic fatigue syndrome, nonspecific dizziness, and neurally mediated syncope. Am J Med Sci. 2006 Jun;331(6):295-303. https://www.ncbi.nlm.nih.gov/pubmed/16775435

 

Chronic fatigue syndrome: an update focusing on phenomenology and pathophysiology

Abstract:

PURPOSE OF REVIEW: Chronic fatigue syndrome is a controversial condition especially concerning its clinical definition and aetiopathogenesis. Most recent research progress has been made in phenomenology and pathophysiology and we focused our review on these two areas.

RECENT FINDINGS: The phenomenology research supports the notion of a discrete fatigue syndrome which can be distinguished from depression and anxiety. The current case definition, however, may need an improvement based on empirical data. Recent advances in understanding the pathophysiology of chronic fatigue syndrome continue to demonstrate the involvement of the central nervous system. Hyperserotonergic state and hypoactivity of the hypothalamic-pituitary-adrenal axis constitute other findings, but the question of whether these alterations are a cause or consequence of chronic fatigue syndrome still remains unanswered. Immune system involvement in the pathogenesis seems certain but the findings on the specific mechanisms are still inconsistent. Genetic studies provide some evidence of the syndrome being a partly genetic condition, but environmental effects seem to be still predominant and identification of specific genes is still at a very early stage.

SUMMARY: The recent findings suggest that further research is needed in improving the current case definition; investigating overlaps and boundaries among various functional somatic syndromes; answering the question of whether the pathophysiologic findings are a cause or consequence; and elucidating the involvement of the central nervous system, immune system and genetic factors.

 

Source: Cho HJ, Skowera A, Cleare A, Wessely S. Chronic fatigue syndrome: an update focusing on phenomenology and pathophysiology. Curr Opin Psychiatry. 2006 Jan;19(1):67-73. https://www.ncbi.nlm.nih.gov/pubmed/16612182

 

Aetiology and pathogenesis of chronic fatigue syndrome: a review

Abstract:

Chronic fatigue syndrome (CFS) is a debilitating disease of uncertain aetiology that is characterised by unexplained, severe fatigue associated with a number of typical symptoms. This paper reviews the scientific literature related to current theories about the aetiology and pathogenesis of CFS by focussing on what appear to be the four most significant aspects in the development and perpetuation of this disease: the role of infectious agents as well as immunological, neuroendocrine, and psychiatric factors. A multifactorial model for the aetiology of CFS, which includes and draws together these four aspects, is proposed; and suggestions are offered regarding approaches to the diagnosis and treatment of this disease.

 

Source: Mihrshahi R, Beirman R. Aetiology and pathogenesis of chronic fatigue syndrome: a review. N Z Med J. 2005 Dec 16;118(1227):U1780. http://www.ncbi.nlm.nih.gov/pubmed/16372029

 

A systematic review describing the prognosis of chronic fatigue syndrome

Abstract:

AIM: To perform a systematic review of studies describing the prognosis of chronic fatigue (CF) and chronic fatigue syndrome (CFS) and to identify occupational outcomes from such studies.

METHOD: A literature search was used to identify all studies describing the clinical follow-up of patients following a diagnosis of CF or CFS. The prognosis is described in terms of the proportion of individuals improved during the period of follow-up. Return to work, other medical illnesses and death as outcomes are also considered, as are variables which may influence prognosis.

RESULTS: Twenty-eight articles met the inclusion criteria and, for the 14 studies of subjects meeting operational criteria for CFS, the median full recovery rate was 5% (range 0-31%) and the median proportion of patients who improved during follow-up was 39.5% (range 8-63%). Less fatigue severity at baseline, a sense of control over symptoms and not attributing illness to a physical cause were all associated with a good outcome. Return to work at follow-up ranged from 8 to 30% in the three studies that considered this outcome.

CONCLUSIONS: Full recovery from untreated CFS is rare. The prognosis for an improvement in symptoms is less gloomy. This review looks at the course of CF/CFS without systematic intervention. However, there is increasing evidence for the effectiveness of cognitive behavioural and graded exercise therapies. Medical retirement should be postponed until a trial of such treatment has been given.

 

Source: Cairns R, Hotopf M. A systematic review describing the prognosis of chronic fatigue syndrome. Occup Med (Lond). 2005 Jan;55(1):20-31. http://occmed.oxfordjournals.org/content/55/1/20.long (Full artricle)

 

Epidemiology of chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome (CFS) is a controversial disorder with different case definitions, aetiological models and proposed treatments. An epidemiological approach is likely to bring some clarity to the field.

AIM: The aim of this article is to review the literature on the epidemiology of fatigue, chronic fatigue and CFS.

METHOD: A literature search was conducted using the databases Medline and Pubmed as well as the reference lists of recent reviews to identify the relevant studies. The aim was not to do a systematic review but to review the key studies in the area to highlight the methodological issues.

RESULTS: The review is organized according to the following areas: the prevalence of fatigue and chronic fatigue, the prevalence and incidence of CFS, epidemiological associations such as gender, social class and psychiatric co-morbidity and CFS in special groups such as those recovering from a viral infection, specific occupational groups and Gulf War veterans.

CONCLUSION: While fatigue as a symptom is very common, CFS is relatively rare. Many of the epidemiological associations seen in specialist clinics are not found in community samples. It is unlikely that one specific causal factor can explain CFS. Future studies should go beyond estimating the prevalence to testing more complex aetiological models.

 

Source: Ranjith G. Epidemiology of chronic fatigue syndrome. Occup Med (Lond). 2005 Jan;55(1):13-9. http://occmed.oxfordjournals.org/content/55/1/13.long (Full article)

 

Chronic fatigue syndrome: a review

Abstract:

Chronic fatigue syndrome is a relatively unknown and underdiagnosed entity in Italy where its epidemiology remains uncertain, as well as its etiology, although it causes important disability in those affected. Classification criteria by Fukuda are available to diagnose the syndrome. Its epidemiology indicates that it is probably more frequent in Northern countries and it is described in Gulf War veterans. Etiological hypotheses include infectious diseases, immunology and neurology. Among these hypotheses sickness behavior mimes certain aspects of this syndrome and is characterized by a cytokine imbalance in the central nervous system and in the periphery. There are no valid therapies available at the moment. In the laboratory of Immunogenetics, we are constituting a biological bank of the syndrome to study the immunogenetic aspects of the disease in the hope of elucidating some of the obscure areas of its etiopathogenesis.

 

Source: Carlo-Stella N, Lorusso L, Candura SM, Cuccia M. Chronic fatigue syndrome: a review. Recenti Prog Med. 2004 Nov;95(11):546-52; quiz 560. [Article in Italian] http://www.ncbi.nlm.nih.gov/pubmed/15598093

 

Chronic fatigue syndrome (cfs)

Abstract:

The Chronic Fatigue Syndrome (CFS) is described based on the revision of Fukuda et al. The question “whether CFS can be discussed as a homogenous disorder?” has been reviewed and the answer is “no”. Other overlapping syndromes are mentioned. Disorders with fatigue as a symptom are depression, somatisation, irritable bowel syndrome, effort-syndrome, hyperventilation, conservation-withdrawal.

Among the pathogenetic factors of CFS immune systems disorders, neuroendocrine abnormalities, autonomic activity, neuroimaging, neuropsychological abnormalities, exercise capacity and muscle function and psychological processes (attribution, perception, symptom avoidance and neutralisation of conflicts) are discussed.

Since CFS cannot be comprehended without knowledge of the ontogenetic development of the affect “fatigue”, it is extensively described. Based on this knowledge, fatigue as an affect and the CFS are embedded in a context, which has as its basis the fight-flight reaction and the conservation-withdrawal reaction. Weighing the evidence, it is concluded that CFS in its varieties can best be understood as a manifestation of the activation of the two biological emergency reactions: fight-flight and conservation-withdrawal.

The physician should interview and examine each individual patient according to the Harvey Cushing dictum: The physician should not only study the diseased organ, but the man with his diseased organ, and not only these. He should comprehend the man with his diseased organ in his environment. This leads to study of the biological, psychological and social factors contributing to each patient’s illness. Work-up and therapy have to be based on this integrated approach. The latter encompasses conflict centred psychotherapy, stepwise increasing physical activation and antidepressive drugs.

 

Source: Adler RH. Chronic fatigue syndrome (cfs). Swiss Med Wkly. 2004 May 15;134(19-20):268-76. http://www.smw.ch/for-readers/archive/backlinks/?url=/docs/archive200x/2004/19/smw-10213.html (Full article)

 

Disability and chronic fatigue syndrome: a focus on function

Abstract:

BACKGROUND: Evidence was sought in the published literature on how best to measure, monitor, and treat disability in patients with chronic fatigue syndrome (CFS).

METHODS: A systematic review was performed of English-language literature published between January 1, 1988, and November 15, 2001. Interventional and observational studies of adults with CFS were eligible if they reported measures of disability and employment. A qualitative synthesis of results relating impairment measures to employment was performed.

RESULTS: Of 3840 studies identified, 37 reported employment status and some measure of mental or physical impairment associated with disability. Most patients with CFS in these studies were unemployed. In 22 studies, the employment status of control subjects was also available. Only depression seemed to be associated with unemployment in patients with CFS. No other measurable impairment seemed to be consistently associated with disability or work outcomes. Only cognitive behavior therapy, rehabilitation, and exercise therapy interventions were associated with restoring the ability to work. No specific patient characteristics were identified as best predictors of positive employment outcomes. No quantitative syntheses of results were performed.

CONCLUSIONS: For questions of disability and employment in CFS, the limitations inherent in the current literature are extensive. Methodologically rigorous, longitudinal, and interventional studies are needed to determine baseline characteristics that are associated with the inability to work and interventions that are effective in restoring the ability to work in the CFS population. Simple and consistent evaluations of functional capacity in patients with CFS are needed.

 

Source: Ross SD, Estok RP, Frame D, Stone LR, Ludensky V, Levine CB. Disability and chronic fatigue syndrome: a focus on function. Arch Intern Med. 2004 May 24;164(10):1098-107. http://www.ncbi.nlm.nih.gov/pubmed/15159267

 

Chronic fatigue syndrome: traditional and community-based approaches to rehabilitation

Abstract:

Chronic fatigue syndrome (CFS) is a controversial condition defined by 6 months or more of unexplained fatigue, and at least four out of eight cognitive and physical symptoms. Over the past 2 decades, CFS has been the subject of significant debate regarding its definition, cause and recommended treatment. Because a cure for the syndrome has not yet been located, efforts to improve functioning and overall quality of life through rehabilitation represent the most practised form of treatment to date.

However, controversy remains as to which approach to rehabilitation is most effective for individuals with CFS. Interventions which take place within real-world environments and utilise community-based organizations such as centres for independent living offer a newly explored means of support and rehabilitation.

The present paper reviews a variety of approaches to rehabilitation for individuals with CFS, describing their applications with different types of patients, and providing critical commentary on the research methodologies used to evaluate them. Innovative community-based rehabilitation programmes and their outcomes are described as an alternative with some promise that may compliment more traditional approaches.

 

Source: Taylor RR. Chronic fatigue syndrome: traditional and community-based approaches to rehabilitation. Health Soc Care Community. 2004 May;12(3):171-85. http://www.ncbi.nlm.nih.gov/pubmed/19777707