Cognitive and Vascular Functioning Following TBI

Description

The investigators will enroll 300 Service Members (SMs) and Veterans who participated in the National Intrepid Center of Excellence (NICoE) intensive outpatient program or Defense and Veterans Brain Injury Center/Traumatic Brain Injury Center of Excellence (DVBIC/TBICoE) 15-Year TBI Natural History of TBI Study (NatHx) at least three years prior to the present evaluation and provided prior blood specimens stored for analysis. Following informed consent, participants will undergo semi-structured interviews assessing posttraumatic stress disorder (PTSD) and updated lifetime TBI history, neurological examination, neuropsychological testing, structural Magnetic Resonance Imaging (MRI) T1, T2, fluid attenuated inversion recovery (FLAIR), diffuse tensor imaging (DTI), as well as novel imaging techniques to assess imaging biomarkers of traumatic cerebrovascular injury (TCVI): 1) functional MRI (fMRI)-Blood Oxygen Level Dependent (BOLD) with hypercapnia challenge to measure cerebrovascular reactivity (CVR); and 2) Dynamic Contrast Enhanced-MRI to assess blood brain barrier integrity, and an additional research blood draw [apolipoprotein E (APOE) genotype; plasma biomarkers including vascular (e.g., vascular endothelial growth factor, von Willebrand Factor, cholesterol, homocysteine), inflammatory (e.g., high sensitivity c-reactive protein, interleukin-6 (IL-6), chitinase-3-like protein 1 (YKL-40)), and neuronal degeneration (e.g., neurofilament light, phosphorylated tau, brain-derived neurotrophic factor, beta amyloid proteins)]. A medical record review will be conducted specifically for current and past history of cerebrovascular risk factors (e.g., hypertension, diabetes, tobacco use) and psychological conditions (e.g., PTSD, depression). The project will also leverage previously collected data, comparing participants’ symptoms, cognitive performance, imaging, and, blood biomarkers to those previously collected through the NICoE, 15-Year study and/or the DOD serum repository, with data from at least two time points on all individuals.