Brain function characteristics of chronic fatigue syndrome: A task fMRI study

Area of Science:

• Neuroscience
• Medical Imaging
• Psychiatry

Background:

• Neurological dysfunction mechanisms in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) remain unclear.
• Investigating brain activity patterns during cognitive challenges is crucial for understanding CFS/ME pathophysiology.

Purpose of the Study:

• To explore the temporal complexity of blood oxygenation level dependent (BOLD) changes in response to the Stroop task in CFS/ME patients.
• To correlate brain signal complexity with patient-reported physical and mental health outcomes.

Main Methods:

• Utilized functional magnetic resonance imaging (fMRI) to measure BOLD responses during a Stroop task in 43 CFS/ME patients and 26 healthy controls (NCs).
• Assessed BOLD signal temporal complexity using sample entropy (SampEn).
• Correlated SampEn values with SF-36 questionnaire scores for physical component summary (PCS) and mental component summary (MCS).

Main Results:

• CFS/ME patients demonstrated significantly longer response times (RTs) but similar accuracy compared to NCs.
• While more BOLD activation regions were observed in CFS/ME patients, their BOLD signal complexity (SampEn) was significantly lower in ten regions.
• BOLD SampEn in specific brain regions, including the medioventral occipital cortex and precentral gyrus, significantly correlated with PCS and MCS scores.

Conclusions:

• CFS/ME patients exhibit altered brain responses to cognitive challenges, characterized by increased activation in wider brain regions to compensate for reduced neural information processing capacity.
• Lower BOLD signal complexity is linked to poorer physical and mental health outcomes in CFS/ME.
• This study provides novel evidence for reduced neural adaptability in CFS/ME, highlighting potential targets for future interventions.