The role of disconnection in explaining disability in multiple sclerosis

Eur Radiol Exp. 2022 Jun 8;6(1):23. doi: 10.1186/s41747-022-00277-x.

Abstract

Background: In multiple sclerosis, the correlation between white matter lesion volumes (LV) and expanded disability status scale (EDSS) is at best moderate, leading to the "clinico-radiological paradox", influenced by many factors, including the lack of information on the spatial localisation of each lesion on synthetic metrics such as LV. We used a probabilistic approach to provide the volume of WM tracts that may be disconnected by lesions and to evaluate its correlation with EDSS.

Methods: Forty-five patients (aged 37.4 ± 6.8 years, mean ± standard deviation; 30 females; 29 relapsing-remitting, 16 progressive) underwent 3-T magnetic resonance imaging. Both LV and the volume of the tracts crossing the lesioned regions (disconnectome volume, DV) were calculated using BCBtoolkit and correlated with EDSS.

Results: T1-weighted LV and DV significantly correlated with EDSS (p ≤ 0.006 r ≥ 0.413) as it was for T2-weighted LV and T2-weighted DV (p ≤ 0.004 r ≥ 0.430), but only T1-weighetd and T2-weighted DVs were EDSS significant predictors (p ≤ 0.001). The correlations of T1-weighted and T2-weighted LV with EDSS were significantly mediated by DV, while no effect of LV on the EDSS-DV correlation was observed.

Conclusion: The volume of disconnected WM bundles mediates the LV-EDSS correlation, representing the lonely EDSS predictor.

Keywords: Diffusion tensor imaging; Disability evaluation; Magnetic resonance imaging; Multiple sclerosis; White matter.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Brain / pathology
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods
  • Multiple Sclerosis* / diagnostic imaging
  • Recurrence
  • White Matter* / pathology