Tag: pathophysiology

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Comprehensive Review

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating chronic disease of unknown aetiology that is recognized by the World Health Organization (WHO) and the United States Center for Disease Control and Prevention (US CDC) as a disorder of the brain. The disease predominantly affects adults, with a peak age of onset of between 20 and 45 years with a female to male ratio of 3:1. Although the clinical features of the disease have been well established within diagnostic criteria, the diagnosis of ME/CFS is still of exclusion, meaning that other medical conditions must be ruled out.

The pathophysiological mechanisms are unclear but the neuro-immuno-endocrinological pattern of CFS patients gleaned from various studies indicates that these three pillars may be the key point to understand the complexity of the disease. At the moment, there are no specific pharmacological therapies to treat the disease, but several studies’ aims and therapeutic approaches have been described in order to benefit patients’ prognosis, symptomatology relief, and the recovery of pre-existing function.

This review presents a pathophysiological approach to understanding the essential concepts of ME/CFS, with an emphasis on the population, clinical, and genetic concepts associated with ME/CFS.

Source: Cortes Rivera M, Mastronardi C, Silva-Aldana CT, Arcos-Burgos M, Lidbury BA. Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Comprehensive Review. Diagnostics (Basel). 2019 Aug 7;9(3). pii: E91. doi: 10.3390/diagnostics9030091. https://www.ncbi.nlm.nih.gov/pubmed/31394725

The chronic fatigue syndrome: a comparative pathway analysis

Abstract:

In this paper, we introduce a method to detect pathological pathways of a disease. We aim to identify biological processes rather than single genes affected by the chronic fatigue syndrome (CFS). So far, CFS has neither diagnostic clinical signals nor abnormalities that could be diagnosed by laboratory examinations. It is also unclear if the CFS represents one disease or can be subdivided in different categories. We use information from clinical trials, the gene ontology (GO) database as well as gene expression data to identify undirected dependency graphs (UDGs) representing biological processes according to the GO database. The structural comparison of UDGs of sick versus non-sick patients allows us to make predictions about the modification of pathways due to pathogenesis.

 

Source: Emmert-Streib F. The chronic fatigue syndrome: a comparative pathway analysis. J Comput Biol. 2007 Sep;14(7):961-72. https://www.ncbi.nlm.nih.gov/pubmed/17803373

 

Orthostatic intolerance in the chronic fatigue syndrome

Abstract:

This study aims to investigate the prevalence and pathophysiology of orthostatic intolerance (OI) and its potential contribution to symptoms of a group of unselected patients with chronic fatigue syndrome (CFS).

Seventy five patients (65 women, 10 men) with CFS were evaluated. During an initial visit, a clinical suspicion as to the likelihood of observing laboratory evidence of OI was assigned. Laboratory investigation consisted of beat-to-beat recordings of heart rate, blood pressure (Finapres), and stroke volume (impedance cardiograph) while supine and during 80 degrees head-up tilt (HUT), during rhythmic deep breathing (6 breaths/min) and during the Valsalva maneuver. The responses of 48 age-matched healthy controls who had no history of OI were used to define the range of normal responses to these three maneuvers.

Forty percent of patients with CFS had OI during head-up tilt. Sixteen exhibited neurally-mediated syncope alone, seven tachycardia (> 35 bpm averaged over the whole of the head-up tilt) and six a mixture of tachycardia and syncope. Eight of 48 controls exhibited neurally-mediated syncope. The responses to the Valsalva maneuver and to deep breathing were similar in controls and patients. On average, the duration of disease and patient age were significantly less and the onset of symptoms was more often subacute in patients with OI than in those without OI.

We conclude that there exists a clinically identifiable subgroup of patients with CFS and OI that differs from control subjects and from those with CFS without OI for whom treatment specifically aimed at improving orthostatic tolerance may be indicated.

 

Source: Schondorf R, Benoit J, Wein T, Phaneuf D. Orthostatic intolerance in the chronic fatigue syndrome. J Auton Nerv Syst. 1999 Feb 15;75(2-3):192-201. http://www.ncbi.nlm.nih.gov/pubmed/10189122

 

Chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a medically unexplained illness characterized by chronic, disabling fatigue, impaired concentration, muscle pain, and other somatic symptoms. The conceptual difficulties associated with all medically unexplained illnesses contribute to the controversy surrounding CFS, which has centered around whether it is best regarded as a medical or as a psychiatric condition. Clinically, such an approach is not helpful, and current research suggests that both pathophysiologic changes and psychosocial factors are important. Pragmatic management based on a detailed assessment of the individual is outlined.

 

Source: Sharpe M. Chronic fatigue syndrome. Psychiatr Clin North Am. 1996 Sep;19(3):549-73. http://www.ncbi.nlm.nih.gov/pubmed/8856816