A comparison of the functional connectome in mild traumatic brain injury and post‐traumatic stress disorder

Abstract

Post‐traumatic stress disorder (PTSD) and mild traumatic brain injury (mTBI) often co‐occur in the context of threat to one's life. These conditions also have an overlapping symptomatology and include symptoms of anxiety, poor concentration and memory problems. A major challenge has been articulating the underlying neurobiology of these overlapping conditions. The primary aim of this study was to compare intrinsic functional connectivity between mTBI (without PTSD) and PTSD (without mTBI). The study included functional MRI data from 176 participants: 42 participants with mTBI, 67 with PTSD and a comparison group of 66 age and sex‐matched healthy controls. We used network‐based statistical analyses for connectome‐wide comparisons of intrinsic functional connectivity between mTBI relative to PTSD and controls. Our results showed no connectivity differences between mTBI and PTSD groups. However, we did find that mTBI had significantly reduced connectivity relative to healthy controls within an extensive network of regions including default mode, executive control, visual and auditory networks. The mTBI group also displayed hyperconnectivity between dorsal and ventral attention networks and perceptual regions. The PTSD group also demonstrated abnormal connectivity within these networks relative to controls. Connectivity alterations were not associated with severity of PTSD or post‐concussive symptoms in either clinical group. Taken together, the similar profiles of intrinsic connectivity alterations in these two conditions provide neural evidence that can explain, in part, the overlapping symptomatology between mTBI and PTSD.

Association of mild traumatic brain injury, post-traumatic stress disorder, and other comorbidities on photosensitivity

“…A dynamic pain connectome has been defined that involves three areas: the Default Mode and Salience Networks along with the Anti-Nociceptive system, which plays a role in the mind wandering away from pain 40 . There is evidence of atypical resting-state functional network activity within these areas in both mild traumatic brain injury and post-traumatic stress disorder, 41–43 which may explain overlapping symptoms in these conditions. In both post-9/11 veteran and civilian populations, altered connectivity within and between the default mode and salience networks has also been suggested to underlie the hypervigilance component in post-traumatic stress disorder 44,45 .…”