Assessing spatial relationships between axonal integrity, regional brain volumes, and neuropsychological outcomes after traumatic axonal injury

Matthew Warner, Carlos Marquez De La Plata, Jeffrey Spence, Jun Yi Wang, Caryn Harper, Carol Moore, Michael Devous, Ramon Diaz-Arrastia

Research output: Contribution to journalArticle

82 Scopus citations

Abstract

Diffuse traumatic axonal injury (TAI) is a type of traumatic brain injury (TBI) characterized predominantly by white matter damage. While TAI is associated with cerebral atrophy, the relationship between gray matter volumes and TAI of afferent or efferent axonal pathways remains unknown. Moreover, it is unclear if deficits in cognition are associated with post-traumatic brain volumes in particular regions. The goal of this study was to determine the relationship between markers of TAI and volumes of cortical and subcortical structures, while also assessing the relationship between cognitive outcomes and regional brain volumes. High-resolution magnetic resonance imaging scans were performed in 24 patients with TAI within 1 week of injury and were repeated 8 months later. Diffusion tensor imaging (DTI) tractography was used to reconstruct prominent white matter tracts and calculate their fractional anisotropy (FA) and mean diffusivity (MD) values. Regional brain volumes were computed using semi-automated morphometric analysis. Pearson's correlation coefficients were used to assess associations between brain volumes, white matter integrity (i.e., FA and MD), and neuropsychological outcomes. Post-traumatic volumes of many gray matter structures were associated with chronic damage to related white matter tracts, and less strongly associated with measures of white matter integrity in the acute scans. For example, left and right hippocampal volumes correlated with FA in the fornix body (r = 0.600, p = 0.001; r = 0.714, p < 0.001, respectively). In addition, regional brain volumes were associated with deficits in corresponding neuropsychological domains. Our results suggest that TAI may be a primary mechanism of post-traumatic atrophy, and provide support for regional morphometry as a biomarker for cognitive outcome after injury.

Original languageEnglish (US)
Pages (from-to)2121-2130
Number of pages10
JournalJournal of neurotrauma
Volume27
Issue number12
DOIs
StatePublished - Dec 1 2010
Externally publishedYes

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Keywords

  • atrophy
  • diffuse axonal injury
  • diffusion tensor imaging
  • traumatic brain injury
  • volumetric magnetic resonance imaging

ASJC Scopus subject areas

  • Clinical Neurology

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