Volgens een recente studie van dr. Daniel Neu en zijn Brusselse collega's

• laat polysomnografisch onderzoek zien dat de diepe slaap van patiënten langer duurt (?), dat zij vaker deels ontwaken en hun ledematen vaker bewegen en dat de slaap meer gefragmenteerd is,
• ervaren patiënten objectief aantoonbare problemen met concentratie en reactiesnelheid,
• is de handgrijpkracht (duur én maximale kracht) verminderd en zijn spieren eerder vermoeid, en
• zijn de concentraties IL-1β, IL-8, IL-10 and TNF-α in het serum aanzienlijk verhoogd, en

terwijl de concentraties IFNγ juist beduidend lager zijn dan die bij gezonde "proefkonijnen".

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.

OBJECTIVES:

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.

METHODS:

16 CFS patients were compared to 14 matched controls.

We assessed

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).

RESULTS:

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.

CONCLUSIONS:

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.

PMID: 24878689