Metabolic neuroimaging of myalgic encephalomyelitis/chronic fatigue syndrome and Long-COVID.
Zhu, Yijuan, Quan, Patrick, Yamazaki, Tadahiro et al. · Immunometabolism (Cobham, Surrey) · 2025 · DOI
Quick Summary
This review examines brain imaging studies that look at how the brains of people with ME/CFS and Long-COVID process energy and nutrients differently. Researchers used advanced scanning techniques to measure glucose and oxygen use in the brain, finding that both conditions show similar patterns of disrupted brain energy metabolism and inflammation. The findings suggest these brain changes might explain why patients experience persistent fatigue, thinking problems, and worsening after physical activity.
Why It Matters
This review is important because it consolidates emerging evidence that brain metabolism abnormalities—detectable through neuroimaging—may underlie ME/CFS and Long-COVID symptoms. If validated as biomarkers, these imaging findings could enable objective diagnosis, help distinguish between patient subgroups, and identify specific molecular targets for new treatments. This addresses a critical gap: currently, diagnosis relies on symptom reporting alone, with no biological confirmatory tests.
Observed Findings
Alterations in cerebral glucose and oxygen metabolism detected via PET imaging in both ME/CFS and Long-COVID patients
Neurotransmitter imbalances revealed by neuroimaging in both conditions
Elevated markers of oxidative stress in brain tissue
Evidence of neuroinflammatory processes in both ME/CFS and Long-COVID
Inconsistencies in metabolite profiles between the two conditions, suggesting potential biological differences
Inferred Conclusions
Metabolic brain imaging abnormalities are shared features of ME/CFS and Long-COVID, suggesting overlapping pathophysiological mechanisms involving impaired brain energy metabolism and neuroinflammation
Neuroimaging has potential to serve as an objective biomarker for diagnosis and patient stratification
Standardizing diagnostic criteria and imaging protocols across studies is essential to improve reproducibility and clinical translation
Further longitudinal and stratified research is needed to distinguish ME/CFS and Long-COVID subtypes and identify therapeutic targets
Remaining Questions
Are the metabolic brain abnormalities observed in neuroimaging studies specific to ME/CFS and Long-COVID, or do they appear in other fatiguing or inflammatory conditions?
What This Study Does Not Prove
This is a review of existing studies, not a new primary research study, so it does not prove cause-and-effect relationships. The review identifies shared imaging abnormalities between ME/CFS and Long-COVID but does not establish whether these findings are specific to these conditions or present in other diseases. The inconsistencies between studies noted by the authors mean that findings are not yet sufficiently standardized for clinical diagnostic use.