Network analysis detects changes in the contralesional hemisphere following stroke

Jonathan Crofts, Desmond Higham, R. Bosnell, S. Jbabdi, P.M. Matthews, T.E.J. Behrens, H. Johansen-Berg

Research output: Contribution to journalArticle

127 Citations (Scopus)

Abstract

Changes in brain structure occur in remote regions following focal damage such as stroke. Such changes could disrupt processing of information across widely distributed brain networks. We used diffusion MRI tractography to assess connectivity between brain regions in 9 chronic stroke patients and 18 age-matched controls. We applied complex network analysis to calculate ‘communicability’, a measure of the ease with which information can travel across a network. Clustering individuals based on communicability separated patient and control groups, not only in the lesioned hemisphere but also in the contralesional hemisphere, despite the absence of gross structural pathology in the latter. In our highly selected patient group, lesions were localised to the left basal ganglia/internal capsule. We found reduced communicability in patients in regions surrounding the lesions in the affected hemisphere. In addition, communicability was reduced in homologous locations in the contralesional hemisphere for a subset of these regions. We interpret this as
evidence for secondary degeneration of fibre pathways which occurs in remote regions interconnected, directly or indirectly, with the area of primary damage. We also identified regions with increased communicability in patients that could represent adaptive, plastic changes post-stroke. Network analysis provides new and powerful tools for understanding subtle changes in interactions across widely distributed brain networks following stroke.
Original languageEnglish
Pages (from-to)161-169
Number of pages9
JournalNeuroImage
Volume54
Issue number1
DOIs
Publication statusPublished - 1 Jan 2011

Keywords

  • brain connectivity
  • unsupervised classification
  • network science
  • tractography
  • diffusion weighted MRI

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