Inderyas et al. (2026)
- Authors: Maira Inderyas, Kiran Thapaliya, Sonya Marshall-Gradisnik, Leighton Barnden
- Institutes: National Centre for Neuroimmunology and Emerging Diseases, Griffith University, Southport, QLD, Australia
- Publisher: Journal of Translational Medicine
- Link: DOI
Summary
This research identifies objective neurological markers that distinguish ME/CFS and Long COVID from healthy individuals and each other. By revealing impaired connectivity in regions governing motivation and cognition, the study provides a biological explanation for ‘brain fog’ and cognitive exhaustion. These findings support the use of advanced 7 Tesla imaging as a diagnostic tool to validate patient experiences and track the effectiveness of future treatments.
What was researched?
The study investigated how functional connectivity between brain regions changes during cognitive tasks in patients with ME/CFS and Long COVID. Researchers specifically looked for differences in brain network coordination during the onset of cognitive fatigue.
Why was it researched?
Both ME/CFS and Long COVID are characterized by debilitating cognitive deficits and fatigue, yet the underlying brain mechanisms remain poorly understood. Understanding these neural patterns is essential for developing objective biomarkers and targeted therapies.
How was it researched?
Using high-resolution 7 Tesla fMRI, researchers scanned 78 participants (32 ME/CFS, 19 Long COVID, and 27 healthy controls) during a Stroop color-word task. Connectivity was measured before and after cognitive fatigue was induced to observe real-time changes in brain communication.
What has been found?
Healthy controls showed increased communication between brain regions during fatigue, whereas patients showed reduced or dysregulated coordination. Long COVID patients exhibited significantly reduced connectivity between the nucleus accumbens and vermis, while ME/CFS patients showed increased connectivity between the cuneiform nucleus and medulla. These patterns correlated with the severity of cognitive symptoms and the duration of illness.
Discussion
The findings suggest that ‘brain fog’ in these conditions results from a failure of the brain’s dopaminergic and subcortical networks to coordinate effectively. While symptoms overlap, the distinct connectivity patterns indicate that ME/CFS and Long COVID may involve different neurobiological pathways.
Conclusion & Future Work
The study concludes that reduced dopaminergic connectivity impairs motivation and cognition in both groups. These unique functional signatures serve as potential biomarkers for diagnosing and distinguishing between these chronic illnesses.