Tuesday, 6 May 2014

The Half Remarkable Question? ME or CFS

Taken from the ME Global Chronicle 4 - http://bit.ly/1kDkjKX 

The Half Remarkable Question?    ME or CFS

Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS): The need of objective assessment, accurate diagnosis, and acknowledging biological and clinical subgroups. An Extract - 

Although Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS) are often considered to be synonyms, the diagnostic criteria for ME and CFS define distinct clinical entities.

Cognitive impairment, (muscle) weakness, circulatory disturbances, marked variability of symptoms, and, above all, post-exertional “malaise”: a long-lasting increase of symptoms after minor exertion, are distinctive symptoms of ME.

This latter phenomenon separates ME, a neuro-immune illness, from chronic fatigue (syndrome), other disorders and deconditioning. The introduction of the label “CFS”, but more importantly the diagnostic criteria for CFS have generated much confusion, mostly because chronic fatigue is a subjective and ambiguous notion.

CFS was redefined in 1994 into unexplained (persistent or relapsing) chronic fatigue, accompanied by at least four out of eight symptoms, e.g. headaches and unrefreshing sleep. 

Since the diagnosis ME doesn’t require “fatigue” and post-exertional malaise and cognitive impairment are not obligatory for the diagnosis CFS, the criteria for ME and CFS define two different patient populations.

However, most of the research into ME and CFS in the last decades was based upon the multivalent CFS criteria, which define a heterogeneous patient group.

Due to the fact that fatigue and other symptoms are non-discriminative, subjective experiences, research has been hampered. Despite the use of subjective and ambiguous criteria and measures, research has established typical abnormalities in ME/CFS repetitively, e.g. immunological aberrations, oxidative and nitrosative stress, neurological anomalies, circulatory deficits and mitochondrial dysfunction.

After describing the context, including the controversy about the nature of ME and CFS, the diagnostic criteria, the etiology, the pathophysiology and presumed effective therapies (Cognitive Behavioral Therapy: CBT and Graded Exercise Therapy: GET), this article reviews the historical context of ME and CFS and the diagnostic criteria (Ramsay, Holmes, Fukuda and International Consensus Criteria) and substantiates why ME and CFS are two partially overlapping, partially disjoint clinical entities.

After stressing the importance of an accurate diagnosis, the article proposes various methods to assess characteristic symptoms objectively. Various authors have questioned the physiological nature of the symptoms and qualified ME/CFS as somatisation.

By using objective measures endless discussions due to using questionnaires and subjective measures can be avoided, e.g. with regard to the physiological origin of symptoms, the level of disability, and the proposed positive and/or negative effects of CBT and CGT in specific patient well-defined groups.

The article then summarizes various characteristic abnormalities which have been repeatedly observed in ME/CFS patients or substantial subgroups repeatedly and the potentially relevant clinical and biological subgroups.

The remainder of the article focuses on recommendations for improvements of patient care (assessment and diagnosis) and more effective research in the future.

To improve future research standards and patient care, it is crucial

* that patients with post-exertional “malaise” (ME) and “CFS” patients without post-exertional phenomena are acknowledged as two separate clinical and research entities;

* that typical symptoms of ME and CFS are assessed objectively as much as possible; by using repeated exercise tests (CPETs) and cognitive tests;

* that the diagnosis of ME and CFS in research and clinical practice is based upon accurate criteria;

* that well-defined clinical subgroups of ME and CFS, e.g., patients with orthostatic intolerance or patients with sudden-onset, are investigated in more detail;

* that biomarkers, e.g. immunological status in rest and after exertion, are used to distinguish and investigate biological subtypes in research;

*and that trials into the efficacy of therapies use objective measures of the clinical status and biomarkers to establish the effects of these therapies in ME or CFS patients or subgroups thereof impartially, e.g. by a (positive) change in the oxygen uptake at the anaerobic threshold and cognitive  tests scores.

Frank N.M. Twisk

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