Volgens een recente studie van
dr. Daniel Neu en zijn Brusselse collega's
Dimensions of pure chronic fatigue:
psychophysical, cognitive and biological correlates in the chronic fatigue syndrome.
Eur J Appl Physiol. 2014 May 31. doi: 10.1007/s00421-014-2910-1.
Neu D, Mairesse O, Montana X, Gilson M, Corazza F, Lefevre N, Linkowski P, Le Bon O, Verbanck P.
To investigate associated dimensions of fatigue
regarding cognitive impairment, psychomotor performances,
muscular effort power and circulating cytokine levels and
their relations to symptom intensity
in a sample of pure chronic fatigue syndrome (CFS) patients
without overlapping objective sleepiness or sleep disorders.
16 CFS patients were compared to 14 matched controls.
structured symptom-scales, polysomnography, multiple sleep latency tests,
attention (Zazzo-Cancellation ZCT, digit-symbol-substitution DSST),
psychomotor vigilance and speed (PVT, finger tapping test, FTT),
dynamometer handgrip force (tonic and phasic trials) and
circulating cytokines (IFN-γ, IL-1b, IL-6, IL-8, IL-10, TNF-α).
In addition to fatigue, CFS patients presented with
higher affective symptom intensity and worse perceived sleep quality.
Polysomnography showed more slow-wave sleep and microarousals in CFS
but similar sleep time, efficiency and light-sleep durations than controls.
Patients presented with impaired attention (DSST, ZCT), slower reaction times (PVT)
but not with lower hit rates (FTT).
Notwithstanding lower grip strength during tonic and phasic trials,
CFS also presented with higher fatigability during phasic trials.
Cytokine levels were increased for
IL-1b, IL-8, IL-10 and TNF-α and
fatigue intensity was correlated to grip strength and IL-8.
In contrast to sleepiness,
chronic fatigue is a more complex phenomenon
that cannot be reduced to one single measured dimension (i.e., sleep propensity).
Showing its relations to different measurements,
our study reflects this multidimensionality,
in a psychosomatic disorder such as CFS.
To obtain objective information,
routine assessments of fatigue should rule out sleepiness,
combine aspects of mental and physical fatigue and focus on fatigability.