Authors: Murray B. Stein, Esther Yuh, Sonia Jain, David O. Okonkwo, Christine L. Mac Donald, Harvey Levin, Joseph T. Giacino, Sureyya Dikmen, Mary J. Vassar, Ramon Diaz-Arrastia, Claudia S. Robertson, Lindsay D. Nelson, Michael McCrea, Xiaoying Sun, Nancy Temkin, Sabrina R. Taylor, Amy J. Markowitz, Geoffrey T. Manley, Pratik Mukherjee on behalf of the TRACK-TBI Investigators
Summary: Background: Brain volumes in regions such as the hippocampus and amygdala have been associated with risk for development of PTSD. The objective of this study was to determine whether a set of regional brain volumes, measured by MRI at 2 weeks following mTBI (GCS 13-15), are predictive of PTSD at 3- and 6-months post-injury.
Methods: This study uses data from TRACK-TBI, a prospective longitudinal study of patients with mTBI. We included patients (N = 421) assessed after evaluation in the Emergency Department, and at 2 weeks (including MRI), 3-, and 6-months post-injury. Probable PTSD diagnosis (PCL-5 score > 33) was the outcome. The Freesurfer 6.0 processing pipeline was used to perform volumetric analysis of 3D T1-weighted MRI at 3 Tesla. Brain regions selected a priori for volumetric analyses were insula, hippocampus, amygdala, superior frontal cortex, rostral and caudal anterior cingulate, and lateral and medial orbitofrontal cortex.
Results: 77 (18.3%) and 70 (16.6%) patients had probable PTSD at 3- and 6-months. A composite volume derived as the first principal component (PC1) incorporating 73.8% of the variance in insula, superior frontal cortex, and rostral and caudal cingulate contributed to prediction of 3-month (but not 6-month) PTSD in multivariable models incorporating other established risk factors.
Conclusions: Results, while in need of replication, provide support for a brain reserve hypothesis of PTSD and proof-of-principle for how prediction of at-risk individuals might be accomplished to enhance prognostic accuracy and to enrich clinical prevention trials for individuals at highest risk of PTSD following mTBI.
Source: Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, available online 27 October 2020