White matter abnormalities in mild traumatic brain injury with and without post-traumatic stress disorder: a subject-specific diffusion tensor imaging study

Abstract

Mild traumatic brain injuries (mTBIs) are often associated with posttraumatic stress disorder (PTSD). In cases of chronic mTBI, accurate diagnosis can be challenging due to the overlapping symptoms this condition shares with PTSD. Furthermore, mTBIs are heterogeneous and not easily observed using conventional neuroimaging tools, despite commonly resulting in diffuse axonal injury. Diffusion tensor imaging (DTI) is sensitive to diffuse axonal injuries and is thus more likely to detect mTBIs, especially when analyses account for the inter-individual variability of these injuries. Using a subject-specific approach, we compared fractional anisotropy (FA) abnormalities between groups with a history of mTBI (n = 35), comorbid mTBI and PTSD (mTBI+PTSD; n = 22), and healthy controls (n = 37). We compared all three groups on the number of abnormal FA clusters derived from subject-specific injury profiles (i.e., individual z-score maps) along a common white matter skeleton. The mTBI+PTSD group evinced a greater number of abnormally low FA clusters relative to both the healthy controls and the mTBI group without PTSD (p < .05). Across the groups with a history of mTBI, increased numbers of abnormally low FA clusters were significantly associated with PTSD symptom severity, depression, post-concussion symptoms, and reduced information processing speed (p < .05). These findings highlight the utility of subject-specific microstructural analyses when searching for mTBI-related brain abnormalities, particularly in patients with PTSD. This study also suggests that patients with a history of mTBI and comorbid PTSD, relative to those without PTSD, are at increased risk of FA abnormalities.

Longitudinal white-matter abnormalities in sports-related concussion

“…These studies included physical phantom scans, traveling human phantom scans, and analyses of non–contact-sport controls across sites. 7 , 15 , 20 For physical phantom scans, each imaging site performs the phantom study periodically and before and after the scanner upgrade. For diffusion MRI, the phantom study used a Function Biomedical Informatics Research Network gel phantom to detect the geometric distortion, eddy current distortion, and k-space spike artifacts.…”

An epigenome-wide association study of posttraumatic stress disorder in US veterans implicates several new DNA methylation loci

“…As it was the closest match to our Discovery Cohort, we requested results from a military cohort meta-analysis. It included 1351 subjects from 7 cohorts: Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS) [25], Marine Resiliency Study (MRS) [26,27], Prospective Research in Stress-related Military Operations (PRISMO) [28,29], The African American and the European American cohorts from the Mid-Atlantic Mental Illness Research Education and Clinical Center PTSD Study (VA-M-AA and VA-M-EA) [30], the Injury and Traumatic Stress study (INTRuST; see e.g., [31][32][33]), and the VA Boston Healthcare System National Center for PTSD (VA-NCPTSD) cohort [1]. In the replication cohort analysis, 42% were current PTSD cases, all of which were assessed with Illumina Infinium HumanMethyla-tion450 BeadChip (450K BeadChips; see Smith et al 2019 for details).…”

Largest genome-wide association study for PTSD identifies genetic risk loci in European and African ancestries and implicates novel biological pathways

“…Subjects were participants in studies of the INTRuST Consortium, some of which are cited. [153][154][155] Potentially traumatic events were identified using the Life Events Checklist for DSM-IV (LEC) 76 and/or the Deployment Risk and Resilience inventory (DRRI). 156 The PTSD Checklist for DSM-IV (PCL) 76 was used to indicate a likely diagnosis of PTSD (or healthy control status); in some cases, this diagnosis was corroborated by the Clinician-Administered PTSD Scale (CAPS).…”