Static and dynamic functional connectivity in patients with chronic fatigue syndrome: use of arterial spin labelling fMRI.
Boissoneault, Jeff, Letzen, Janelle, Lai, Song et al. · Clinical physiology and functional imaging · 2018 · DOI
Quick Summary
Researchers used a brain imaging technique to compare how the brains of people with ME/CFS and healthy people process information during a tiring mental task. They found that people with ME/CFS had different patterns of communication between brain regions, and these patterns were linked to how fatigued they felt. This suggests that the fatigue experienced in ME/CFS may be related to how different parts of the brain work together.
Why It Matters
This is the first study to examine both static and dynamic brain connectivity patterns during cognitive exertion in ME/CFS, providing neurobiological evidence that fatigue symptoms may reflect measurable disruptions in how brain networks communicate. Understanding these network differences could eventually lead to better diagnostic tools and targeted treatments that address the underlying brain dysfunction rather than just symptom management.
Observed Findings
Healthy controls showed greater increases in static functional connectivity between the insula and temporo-occipital brain regions compared to CFS patients during cognitive exertion.
CFS patients showed paradoxical increased connectivity between the inferior frontal gyrus and cerebellum/temporal structures, whereas this connectivity declined in healthy controls.
CFS patients demonstrated lower dynamic functional connectivity between the hippocampus and right superior parietal lobule.
Both static and dynamic connectivity changes correlated with participants' ratings of task-related fatigue increases.
Regional cerebral blood flow abnormalities in CFS appear associated with disrupted functional neural networks.
Inferred Conclusions
Perturbations in both static and dynamic functional connectivity may underlie the task-induced fatigue reported by ME/CFS patients.
The brain's inability to maintain normal connectivity patterns during cognitive demands represents a potential neurobiological mechanism of fatigue in ME/CFS.
Functional connectivity abnormalities during cognitive exertion could reflect a fundamental difference in how CFS patients' brains allocate and sustain neural resources.
Remaining Questions
Do these connectivity changes persist or worsen after cognitive exertion, and are they associated with post-exertional malaise (the hallmark relapse in ME/CFS)?
What This Study Does Not Prove
This study cannot establish whether the observed brain connectivity changes cause fatigue or result from it—the relationship could be bidirectional. The small sample size (19 CFS patients) limits generalizability, and the findings describe only a single cognitive task and do not address post-exertional malaise, which is a defining feature of ME/CFS. The authors note these findings may not apply to other fatiguing conditions without further research.
Tags
Symptom:Cognitive DysfunctionFatigue
Biomarker:Neuroimaging
Method Flag:Weak Case DefinitionSmall SampleExploratory Only
About the PEM badge: “PEM required” means post-exertional malaise was an explicit required diagnostic criterion for participant inclusion in this study — not that PEM was studied, observed, or discussed. Studies using criteria that do not require PEM (e.g. Fukuda, Oxford) are tagged “PEM not required”. How the atlas works →
Are these brain connectivity patterns specific to ME/CFS or do they occur in other conditions with chronic fatigue (cancer, chronic pain, multiple sclerosis)?
Could interventions that target these specific brain networks improve fatigue symptoms in ME/CFS patients?
Do connectivity patterns normalize with recovery, and can they serve as biomarkers to assess treatment effectiveness?