Two Coarse Spatial Patterns of Altered Brain Microstructure Predict Post-traumatic Amnesia in the Subacute Stage of Severe Traumatic Brain Injury

Research output: Contribution to journal/Conference contribution in journal/Contribution to newspaperJournal articleResearchpeer-review

DOI

  • Sara H. Andreasen
  • Kasper W. Andersen, University of Copenhagen
  • ,
  • Virginia Conde, University of Copenhagen, Norwegian University of Science and Technology
  • ,
  • Tim B. Dyrby, University of Copenhagen, Technical University of Denmark
  • ,
  • Oula Puonti, University of Copenhagen
  • ,
  • Lars P. Kammersgaard, University of Copenhagen
  • ,
  • Camilla G. Madsen, University of Copenhagen
  • ,
  • Kristoffer H. Madsen, University of Copenhagen, Technical University of Denmark
  • ,
  • Ingrid Poulsen
  • Hartwig R. Siebner, University of Copenhagen

Introduction: Diffuse traumatic axonal injury (TAI) is one of the key mechanisms leading to impaired consciousness after severe traumatic brain injury (TBI). In addition, preferential regional expression of TAI in the brain may also influence clinical outcome. Aim: We addressed the question whether the regional expression of microstructural changes as revealed by whole-brain diffusion tensor imaging (DTI) in the subacute stage after severe TBI may predict the duration of post-traumatic amnesia (PTA). Method: Fourteen patients underwent whole-brain DTI in the subacute stage after severe TBI. Mean fractional anisotropy (FA) and mean diffusivity (MD) were calculated for five bilateral brain regions: fronto-temporal, parieto-occipital, and midsagittal hemispheric white matter, as well as brainstem and basal ganglia. Region-specific calculation of mean FA and MD only considered voxels that showed no tissue damage, using an exclusive mask with all voxels that belonged to local brain lesions or microbleeds. Mean FA or MD of the five brain regions were entered in separate partial least squares (PLS) regression analyses to identify patterns of regional microstructural changes that account for inter-individual variations in PTA. Results: For FA, PLS analysis revealed two spatial patterns that significantly correlated with individual PTA. The lower the mean FA values in all five brain regions, the longer that PTA lasted. A pattern characterized by lower FA values in the deeper brain regions relative to the FA values in the hemispheric regions also correlated with longer PTA. Similar trends were found for MD, but opposite in sign. The spatial FA changes as revealed by PLS components predicted the duration of PTA. Individual PTA duration, as predicted by a leave-one-out cross-validation analysis, correlated with true PTA values (Spearman r = 0.68, ppermutation = 0.008). Conclusion: Two coarse spatial patterns of microstructural damage, indexed as reduction in FA, were relevant to recovery of consciousness after TBI. One pattern expressed was consistent with diffuse microstructural damage across the entire brain. A second pattern was indicative of a preferential damage of deep midline brain structures.

Original languageEnglish
Article number800
JournalFrontiers in Neurology
Volume11
ISSN1664-2295
DOIs
Publication statusPublished - 4 Sep 2020

    Research areas

  • diffusion tensor imaging, disorders of consciousness, partial least squares analysis, post-traumatic amnesia, prediction, traumatic brain injury

See relations at Aarhus University Citationformats

ID: 197619416