Donald Staines, Sonya Marshall-Gradisnik, Leighton Barnden en anderen
van het National Centre for Neuroimmunology
and Emerging Diseases
hebben m.b.v. een functionele MRI-methode (BOLD) de response van de hersenen
van 43 CVS-patiënten en 26 gezonde 'proefkonijnen' op een Stroop-test geanalyseerd.
Het aantal foute antwoorden van patiënten week niet af van dat van gezonde proefpersonen,
maar CVS-patiënten hadden (significant) meer tijd nodig om de test uit te voeren.
CVS-patiënten gebruikten aanzienlijk meer hersendelen om de taak te volbrengen,
de 'intensiteit' van de hersensignalen in die hersendelen was echter aanzienlijk minder.
Het lijkt erop dat het inschakelen van extra 'hersencapaciteit'
moet compenseren voor verminderde informatieverwerkende capaciteit.
Dat patiënten meer hersencapaciteit (moeten) gebruiken om (complexe) cognitieve taken
uit te voeren, is eerder in andere studies ook geconstateerd
(klik hier, hier,
hier en hier)
De auteurs achten het aannemelijk dat de verminderde informatieverwerkende capaciteit
het gevolg is van afgenomen neurale responses (de activiteit van zenuwcellen) en/of verminderde
neurovasculaire koppeling (de relatie tussen neurale activiteit en de doorbloeding op die locatie).
Brain function characteristics of chronic fatigue syndrome: A task fMRI study
NeuroImage: Clinical. 2018;19:279-286. https://doi.org/10.1016/j.nicl.2018.04.025.
Shan ZY, Finegan K, Bhuta S, Ireland T, Staines DR, Marshall-Gradisnik SM, Barnden LR.
Highlights
- CFS patients recruit larger BOLD activation areas for the Stroop task.
- BOLD signal complexities in CFS are lower in ten activated regions.
- The BOLD signal complexity is correlated with the SF-36 health score across all subjects.
- The BOLD signal complexity explains more than 40% of variance in the health score across all subjects.
Abstract
The mechanism underlying neurological dysfunction
in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is yet to be established.
This study investigated
the temporal complexity of blood oxygenation level dependent (BOLD) changes
in response to the Stroop task in CFS patients.
43 CFS patients (47.4 ± 11.8 yrs) and 26 normal controls (NCs, 43.4 ± 13.9 yrs)
were included in this study.
Their mental component summary (MCS) and physical component summary (PCS)
from the 36-item Short Form Health Survey (SF-36) questionnaire were recorded.
Their Stroop colour-word task performance was measured by accuracy and response time (RT).
The BOLD changes associated with the Stroop task were evaluated
using a 2-level general linear model approach.
The temporal complexity of the BOLD responses,
a measure of information capacity and thus adaptability to a challenging environment,
in each activated region was measured by sample entropy (SampEn).
The CFS patients showed
significantly longer RTs than the NCs (P < 0.05) but no significant difference in accuracy.
One sample t-tests for the two groups (Family wise error adjusted PFWE < 0.05) showed
more BOLD activation regions in the CFS,
although a two sample group comparison did not show significant difference.
BOLD SampEns in ten regions were significantly lower (FDR-q < 0.05) in CFS patients.
BOLD SampEns in 15 regions were significantly associated with PCS (FDR-q < 0.05) and
in 9 regions were associated with MCS (FDR-q < 0.05) across all subjects.
SampEn of the BOLD signal in the medioventral occipital cortex
could explain 40% and 31% of the variance in the SF-36 PCS and MCS scores, and
those in the precentral gyrus could explain an additional 16% and 7% across all subjects.
This is the first study to investigate BOLD signal SampEn in response to tasks in CFS.
The results suggest
the brain responds differently to a cognitive challenge in patients with CFS,
with recruitment of wider regions to compensate for lower information capacity.
Keywords
Chronic fatigue syndrome, fMRI, Sample entropy, Stroop task, Event related fMRI
https://www.sciencedirect.com/sdfe/pdf/download/file/pii/
S2213158218301347/1-s2.0-S2213158218301347-main.pdf
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