Cortical and white matter lesion topology influences focal corpus callosum atrophy in multiple sclerosis

J Neuroimaging. 2022 May;32(3):471-479. doi: 10.1111/jon.12977. Epub 2022 Feb 14.


Background and purpose: Corpus callosum (CC) atrophy is a strong predictor of multiple sclerosis (MS) disability but the contributing pathological mechanisms remain uncertain. We aimed to apply advanced MRI to explore what drives the often nonuniform callosal atrophy.

Methods: Prospective brain 7 Tesla and 3 Tesla Human Connectom Scanner MRI were performed in 92 MS patients. White matter, leukocortical, and intracortical lesions were manually segmented. FreeSurfer was used to segment the CC and topographically classify lesions per lobe or as deep white matter lesions. Regression models were calculated to predict focal CC atrophy.

Results: The frontal and parietal lobes contained the majority (≥80%) of all lesion classifications in both relapsing-remitting and secondary progressive MS subtypes. The anterior subsection of the CC had the smallest proportional volume difference between subtypes (11%). Deep, temporal, and occipital white matter lesions, and occipital intracortical lesions were the strongest predictors of middle-posterior callosal atrophy (adjusted R2 = .54-.39, P < .01).

Conclusions: Both white matter and cortical lesions contribute to regional corpus callosal atrophy. The lobe-specific lesion topology does not fully explain the inhomogeneous CC atrophy.

Keywords: atrophy; corpus callosum; magnetic resonance imaging; multiple sclerosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Atrophy / pathology
  • Corpus Callosum / diagnostic imaging
  • Corpus Callosum / pathology
  • Humans
  • Leukoencephalopathies* / pathology
  • Magnetic Resonance Imaging / methods
  • Multiple Sclerosis* / pathology
  • Multiple Sclerosis, Relapsing-Remitting* / pathology
  • Prospective Studies
  • White Matter* / diagnostic imaging
  • White Matter* / pathology