Citation

Lopez KC, Leary JB, Pham DL, Chou YY, Dsurney J, Chan L. J. Neurotrauma 2016; 34(1): 16-22.

Affiliation

Center for Neuroscience and Regenerative Medicine, Phenotyping Core, Bethesda, Maryland, United States ; chanle@cc.nih.gov.

Copyright

(Copyright © 2016, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2015.4323

PMID

26942337

Abstract

Post-traumatic stress disorder (PTSD) is commonly associated with mild traumatic brain injury (mTBI). To better understand their relationship, we examined neuroanatomical structures and neuropsychological performance in a sample of individuals with mTBI, with and without PTSD symptoms. Thirty-nine subjects with mTBI were dichotomized into those with (n=12) and without (n=27) significant PTSD symptoms based on scores on the PTSD Checklist. Using a region-of-interest approach, fronto-temporal volumes, fiber bundles obtain by DTI, and neuropsychological scores were compared between the two groups. After controlling for total intracranial volume and age, subjects with mTBI and PTSD symptoms exhibited volumetric differences in the entorhinal cortex, an area associated with memory networks, relative to mTBI-only patients (F=4.28, p=.046). Additionally, subjects with PTSD symptoms showed reduced white matter integrity in the right cingulum bundle (Axial diffusivity: F=6.04, p=.020). Accompanying these structural alterations, mTBI and PTSD subjects also showed impaired performance in encoding (F=5.98, p=.019) and retrieval (F=7.32, p=.010) phases of list learning and in tests of processing speed (WAIS Processing Speed Index: F=12.23, p=.001; Trails A: F=5.56, p=.024). Increased volume and white matter disruptions in these areas, commonly associated with memory functions, may be related to functional disturbances during cognitively demanding tasks. Differences in brain volume and white matter integrity between mTBI subjects and those with mTBI and comorbid PTSD symptoms point to neuroanatomical differences underlying poorer recovery of mTBI subjects who experience PTSD symptoms. These findings support theoretical models of PTSD's relationship to learning difficulties.

Language: en