E2 ModeratePreliminaryPEM ?Reviewed
Standard · 3 min

Neuroinflammation in Patients with Chronic Fatigue Syndrome/Myalgic Encephalomyelitis

Yasuhito Nakatomi, Kei Mizuno, Akira Ishii et al. · Brain, Behavior, and Immunity · 2014 · DOI

Quick Summary

Japanese researchers used PET imaging with a neuroinflammation tracer (PK11195) in 9 ME/CFS patients and healthy controls. They found significantly elevated neuroinflammation signals across multiple brain regions in ME/CFS patients, particularly in the cingulate cortex, thalamus, and brainstem — areas regulating fatigue and cognition.

Why It Matters

This study independently corroborated neuroinflammation findings from other groups using direct PET imaging. It identified specific brain regions showing elevated glial activation in ME/CFS, providing anatomical detail to the neuroinflammation hypothesis.

What This Study Does Not Prove

With only 9 ME/CFS patients, this is an underpowered study. The PK11195 tracer has relatively low specificity for microglia vs. macrophages. Replication with larger samples and newer tracers is needed.

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Topics

Tags

Method Flag:PEM_UNCLEARSmall SampleEXPLORATORYBIOLOGICALLY_RELEVANT

Metadata

DOI
10.1016/j.bbi.2014.04.001
Sample size
9 patients
Control group
Yes
Review status
Editor reviewed
Evidence level
Single-study or moderate support from human research
Last updated
7 April 2026