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ME en CVS:

de noodzaak van

objectivering van


accurate diagnoses en










In een recente bijdrage in Frontiers of Physiology schetst ondergetekende de noodzaak

  • van objectivering van karakteristieke symptomen van ME/CVS, zoals post-exertionele "malaise",
  • van het maken van een onderscheid van "CVS"-patiŽnten met en zonder post-exertionele "malaise",
  • van het stellen van een accurate diagnose (ME of CVS),
  • van het onderkennen van duidelijke gedefinieerde subgroepen
  • op basis van symptomen (bij voorkeur objectief vastgesteld) en biomarkers,

  • van de noodzaak om de situatie van patiŽnten voorafgaand, tijdens en na trials met (veron-
  • dersteld effectieve) behandelingen met objectieve maatstaven continu in de gaten te houden.






Myalgic Encephalomyelitis (ME) and Chronic Fatigue Syndrome (CFS):

The need of objective assessment, accurate diagnosis,

and acknowledging biological and clinical subgroups.

Front Physiol. 2014 Mar 4;5. doi: 10.3389/fphys.2014.00109.

Frank N.M. Twisk



Perspective Article




Although Myalgic Encephalomyelitis and Chronic Fatigue Syndrome are used interchangeably,

the diagnostic criteria define two 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 a minor exertion,

are distinctive symptoms of Myalgic Encephalomyelitis (ME).


This latter phenomenon separates ME, a neuro-immune illness,

from chronic fatigue (syndrome), other disorders and deconditioning.


The introduction of the label,

but more importantly the diagnostic criteria for Chronic Fatigue Syndrome (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.


Most of the research into ME and/or 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.


Various authors have questioned the physiological nature of the symptoms and

qualified ME/CFS as somatisation.


However, various typical symptoms can be assessed objectively using standardized methods.


Despite subjective and unclear criteria and measures,

research has observed specific abnormalities in ME/CFS repetitively,

e.g. immunological abnormalities, oxidative and nitrosative stress,

neurological anomalies, circulatory deficits and mitochondrial dysfunction.


However, to improve future research standards and patient care, it is crucial

  • that patients with post-exertional malaise (ME) and patients without this odd phenomenon
  • are acknowledged as separate clinical entities,

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

    an objective assessment of characteristic symptoms, as much as possible,

  • that well-defined clinical and biological subgroups of ME and CFS patients
  • are investigated in more detail, and

  • that patients are monitored before, during and after interventions
  • with objective measures and biomarkers.





Myalgic Encephalomyelitis, Chronic Fatigue Syndrome, Assessment,

Diagnosis, Immune System, Post-exertional Malaise, Subgroups




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