Page 277 - MEGIN Book Of Abstracts - 2023

ABSTRACT Post-traumatic stress disorder (PTSD) is Center, Bethesda, MD, USA; Behavioral Biology Branch, Walter
a common condition in post-deployment service Reed Army Institute of Research, Silver Spring, MD, USA. Elec-
members (SM). SMs of the conflicts in Iraq and Afghani- tronic address: [email protected]
stan also frequently experience traumatic brain injury
(TBI) and exposure to blasts during deployments. This ABSTRACT We recorded magnetoencephalography
study evaluated the effect of these conditions and data during a visual recognition task in participants
experiences on functional brain connectomes in post- with combat exposure (n = 40, age: 41.2 ± 7.2 years) to
deployment, combat-exposed veterans. Functional investigate the relationship between the evoked brain
brain connectomes were created using 5-min resting- activity, behavioral performance, and the severity of
state magnetoencephalography data. Well-established their post-traumatic stress symptoms assessed using
clinical interviews determined current PTSD diagnosis, the PTSD Check List for DSM V version (PCL-5). In an
as well as deployment-acquired mild TBI and history initial study session, participants were presented with a
of exposure to blast. Linear regression examined the series of images of outdoor scenes and were instructed
effect of these conditions on functional brain connec- to study the images for an upcoming recognition test.
tomes beyond covariates. There were significant inter- In a subsequent session, the original images were
actions between blast-related mild TBI and PTSD after shown intermixed with novel images while participants
correction for multiple comparisons including num- performed the recognition task. PCL-5 scores were
ber of nodes (non-standardized parameter estimate negatively correlated with discrimination performance
[PE] = -12.47), average degree (PE = 0.05), and connec- and with the recognition accuracy for original images.
tion strength (PE = 0.05). A main effect of blast-related During the recognition session, higher PCL-5 scores
mild TBI was observed on the threshold level. These were associated with reduced relative power of the
results demonstrate a distinct functional connectome evoked response to original images from 100 ms to
presentation associated with the presence of both 300 ms following the image onset over a distributed
blast-related mild TBI and PTSD. These findings suggest brain network including the bilateral inferior frontal
the possibility that blast-related mild TBI alterations in gyri, left middle frontal gyrus, left supramarginal gyrus,
functional brain connectomes affect the presentation right precuneus and the bilateral superior temporal
or progression of recovery from PTSD. The current re- gyri. These findings indicate that the lower recognition
sults offer mixed support for hyper-connectivity in the performance in participants with higher PTSD symp-
chronic phase of deployment TBI. tom severity is associated with altered cortical activity
in brain regions that are known to play a role in the
Keywords: PTSD, TBI, connectome, deployment, network elaboration on visual cues that supports recollection.

Journal of neurotrauma (2021), Vol. 38, No. 22 (34435885) Keywords: Magnetoencephalography, Post-traumatic
(4 citations) stress disorder, Predictive coding, Recognition memory

NeuroImage. Clinical (2021), Vol. 31 (34284337) (0
Post-traumatic stress disorder is associated with citations)
alterations in evoked cortical activation during
visual recognition of scenes (2021)
Teasing apart trauma: neural oscillations
Popescu, Mihai; Popescu, Elena-Anda; DeGraba, differentiate individual cases of mild traumatic
Thomas J; Hughes, John D brain injury from post-traumatic stress disorder
even when symptoms overlap (2021)
National Intrepid Center of Excellence, Walter Reed National
Military Medical Center, Bethesda, MD, USA; National Intrepid Zhang, Jing; Emami, Zahra; Safar, Kristina; McCunn,
Center of Excellence, Walter Reed National Military Medical Patrick; Richardson, J Don; Rhind, Shawn G; da Costa,

 ontents  Index 256
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