[Brain Science on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome].
Watanabe, Yasuyoshi · Brain and nerve = Shinkei kenkyu no shinpo · 2018 · DOI
Quick Summary
This study examined the brains of people with ME/CFS using three types of imaging technology (PET scans, MRI, and MEG) to look for physical differences compared to healthy people. Researchers found that people with ME/CFS have reduced blood flow and energy use in certain brain areas, decreased levels of important chemical messengers, and inflammation in the brain that appears connected to symptom severity. These findings suggest ME/CFS involves real, measurable brain changes rather than being purely psychological.
Why It Matters
This research provides objective biological evidence that ME/CFS involves measurable brain abnormalities, supporting the legitimacy of the condition as a neurological disorder rather than a psychiatric one. Identifying neuroinflammation as a potential core mechanism could guide development of targeted treatments and objective diagnostic biomarkers for ME/CFS patients who currently lack definitive diagnostic tests.
Observed Findings
Decreased regional cerebral blood flow and glucose utilization in people with ME/CFS compared to healthy controls
Reduced acetyl-L-carnitine uptake and decreased serotonin and glutamate transporter densities, particularly in the anterior cingulate cortex
Widespread neuroinflammation detected on PET imaging in ME/CFS patients, associated with severity of neuropsychological symptoms
Prefrontal cortical atrophy observed on structural MRI in ME/CFS patients
Abnormal motor control patterns ('over-guarding phenomenon') detected using functional MRI
Inferred Conclusions
Neuroinflammation is present in multiple brain regions in ME/CFS and correlates with neuropsychological symptom severity, suggesting it may be central to disease pathophysiology
Measurement of neuroinflammation could provide objective diagnostic criteria and guide therapeutic development for ME/CFS
Multiple neuroimaging modalities reveal consistent patterns of reduced brain energy metabolism and altered neurotransmitter function in ME/CFS
Remaining Questions
Is neuroinflammation the primary driver of ME/CFS pathology, or does it develop secondarily in response to other disease mechanisms?
What proportion of ME/CFS patients show these brain imaging abnormalities, and do imaging patterns correlate with specific disease subtypes or symptom presentations?
What This Study Does Not Prove
This study does not establish whether brain inflammation is the primary cause of ME/CFS or a consequence of the disease process. The findings are correlational rather than causal—showing that neuroinflammation associates with symptoms does not prove inflammation directly causes them. The review also does not demonstrate that these brain changes are specific to ME/CFS or present in all patients with the condition.