Mapping of pathological change in chronic fatigue syndrome using the ratio of T1- and T2-weighted MRI scans, by Kiran Thapaliya, Sonya Marshall-Gradisnik, Don Staines, Leighton Barnden in NeuroImage: Clinical Vol 28, 2020, 102366 [doi.org/10.1016/j.nicl.2020.102366]

Research highlights

• We showed increased T1w/T2w in ME/CFS in contrast to other neurodegenerative diseases.
• Higher T1w/T2w occurred in basal ganglia and white matter tracts.
• Increased T1w/T2w indicates increased myelin and/or iron levels.
• T1w/T2w regressions vs clinical measures were abnormal in cingulate cortex and white matter foci.

Research abstract:

Myalgic Encephalomyelitis or Chronic Fatigue Syndrome (ME/CFS) subjects suffer from a variety of cognitive complaints indicating that the central nervous system plays a role in its pathophysiology.

Recently, the ratio T1w/T2w has been used to study changes in tissue myelin and/or iron levels in neurodegenerative diseases such as multiple sclerosis and schizophrenia.

In this study, we applied the T1w/T2w method to detect changes in tissue microstructure in ME/CFS patients relative to healthy controls. We mapped the T1w/T2w signal intensity values in the whole brain for forty-five ME/CFS patients who met Fukuda criteria and twenty-seven healthy controls and applied both region- and voxel-based quantification. We also performed interaction-with-group regressions with clinical measures to test for T1w/T2w relationships that are abnormal in ME/CFS at the population level.

Region-based analysis showed significantly elevated T1w/T2w values (increased myelin and/or iron) in ME/CFS in both white matter (WM) and subcortical grey matter. The voxel-based group comparison with sub-millimetre resolution voxels detected very significant clusters with increased T1w/T2w in ME/CFS, mostly in subcortical grey matter, but also in brainstem and projection WM tracts. No areas with decreased T1w/T2w were found in either analysis. ME/CFS T1w/T2w regressions with heart-rate variability, cognitive performance, respiration rate and physical well-being were abnormal in both gray and white matter foci.

Our study demonstrates that the T1w/T2w approach is very sensitive and shows increases in myelin and/or iron in WM and basal ganglia in ME/CFS.