Preliminary findings of cortical thickness abnorma

Authors: D F Tate G E York M W Reid D B Cooper L Jones D A Robin J E Kennedy J Lewis

Publish Date: 2013/10/08

Volume: 8, Issue: 1, Pages: 102-109

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Abstract

Though cortical abnormalities have been demonstrated in moderate and severe traumatic brain injured TBI patients there have been no studies examining cortical changes following blast related mild TBI mTBI The purpose of this study was to determine the effects and functional relevance of blast mTBI on cortical thickness in a small cohort of carefully screened blast injured US Service Members SM Twelve SM with mTBI acquired through blast injury were compared to 11 demographically matched control SM without TBI Both mTBI and control participants were active duty and had completed a combat deployment Subjects underwent MRI examination and the T1 weighted anatomic images were processed using the FreeSurfer suite of tools Cortical thickness maps were compared between groups and examined for relationships with time since injury TSI Utilizing a large database of functional imaging results BrainMap significant regions of interest ROI were used to determine the behavioral profiles most consistently associated with the specific ROI In addition clinical variables were examined as part of posthoc analysis of functional relevance Group comparisons controlling for age demonstrated several significant clusters of cortical thinning for the blast injured SM After multiple comparisons correction False Discovery Rate FDR two left hemisphere clusters remained significant left superior temporal STG and frontal SFG gyri No clusters were significantly correlated with TSI after FDR correction Behavioral analysis for the STG and SFG clusters demonstrated three significant behavioral/cognitive subdomains each associated with audition and language Blast injured SMs demonstrated distinct areas of cortical thinning in the STG and SFG These areas have been previously shown to be associated with audition and language Posthoc analyses of clinical records demonstrated significant abnormal audiology reports for the blast injured SM suggesting that the thinning in these ROIs might be related to injury to the external auditory system rather than direct injury to the brain from the blast It is clear that additional replication is needed in much larger cohorts Importantly the combination of imaging tools and methods in this study successfully demonstrated the potential to define unique ROIs and functional correlates that can be used to design future studiesThe views opinions and/or findings contained in this manuscript are those of the authors and should not be construed as an official Department of Defense or Veterans Affairs position policy or decision unless so designated by other documentation Research on this article was done under Contract W91YTZ12C0132 In the conduct of this research the investigators adhered to the policies regarding the protection of human subjects as prescribe by Code of Federal Regulations CFR Title 45 Volume 1 Part 46 Title 32 Chapter1 Part 219 and Title 21 Chapter 1 Part 50 Protection of Human Subjects

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