To compare tissue microstructural differences between individuals with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) and long COVID using Diffusion Tensor Imaging (DTI) and Diffusion Kurtosis Imaging (DKI).
Approach:
Participants: 37 ME/CFS participants, 19 long COVID participants, and 27 healthy controls were recruited.
Data Acquisition: Data were acquired using a 3 Tesla (3T) Prisma MRI scanner.
Analysis Methods: DTI and DKI metrics were analyzed using MRtrix and Designer software, with voxel-based statistical analysis performed using SPM12 in MATLAB.
Correlation Analysis: Correlation analysis was conducted between DTI, DKI metrics and clinical measures such as duration of illness and fatigue severity.
Key Findings:
Individuals with ME/CFS showed microstructural alterations in the cingulum, supplementary motor areas, and parts of the corpus callosum (all p < 0.05).
Long COVID participants demonstrated microstructural alterations in regions including the fusiform and precentral gyrus and in major white matter tracks (all p < 0.05).
Direct comparisons revealed significant differences in the left corona radiata between ME/CFS and long COVID (p = 0.001).
Interpretation:
Limitations:
The study's sample size may limit the generalizability of the findings.
The cross-sectional design does not allow for causal inferences.
Conclusion:
This study identifies distinct tissue microstructural alterations in ME/CFS and long COVID.
