Page 312 - MEGIN Book Of Abstracts - 2023

Department of Neurobiology and Anatomy, Wake Forest Teasing apart trauma: neural oscillations
School of Medicine, Winston-Salem, North Carolina, USA; differentiate individual cases of mild traumatic
Department of Neurology, Wake Forest School of Medicine, brain injury from post-traumatic stress disorder
Winston-Salem, North Carolina, USA; Department of Physiol- even when symptoms overlap (2021)
ogy and Pharmacology, Wake Forest School of Medicine,
Winston-Salem, North Carolina, USA; Division of Biomedi- Zhang, Jing; Emami, Zahra; Safar, Kristina; McCunn,
cal Sciences, Edward Via College of Osteopathic Medicine, Patrick; Richardson, J Don; Rhind, Shawn G; da Costa,
Blacksburg, Virginia, USA Leodante; Jetly, Rakesh; Dunkley, Benjamin T

ABSTRACT Post-traumatic stress disorder (PTSD) is Neurosciences & Mental Health, SickKids Research Institute,
a common condition in post-deployment service Toronto, ON, Canada. jzhangcad@gmail.com; MacDonald
members (SM). SMs of the conflicts in Iraq and Afghani- Franklin OSI Research Centre, London, ON, Canada; Defence
stan also frequently experience traumatic brain injury Research and Development Canada, Toronto, Canada;
(TBI) and exposure to blasts during deployments. This Department of Surgery, University of Toronto, Toronto, ON,
study evaluated the effect of these conditions and Canada; Department of Psychiatry, Faculty of Medicine,
experiences on functional brain connectomes in post- Dalhousie University, Halifax, NS, Canada; Department of
deployment, combat-exposed veterans. Functional Medical Imaging, University of Toronto, Toronto, ON, Canada
brain connectomes were created using 5-min resting-
state magnetoencephalography data. Well-established ABSTRACT Post-traumatic stress disorder (PTSD) and
clinical interviews determined current PTSD diagnosis, mild traumatic brain injury (mTBI) are highly prevalent
as well as deployment-acquired mild TBI and history and closely related disorders. Affected individuals often
of exposure to blast. Linear regression examined the exhibit substantially overlapping symptomatology - a
effect of these conditions on functional brain connec- major challenge for differential diagnosis in both mili-
tomes beyond covariates. There were significant inter- tary and civilian contexts. According to our symptom
actions between blast-related mild TBI and PTSD after assessment, the PTSD group exhibited comparable
correction for multiple comparisons including num- levels of concussion symptoms and severity to the mTBI
ber of nodes (non-standardized parameter estimate group. An objective and reliable system to uncover the
[PE] = -12.47), average degree (PE = 0.05), and connec- key neural signatures differentiating these disorders
tion strength (PE = 0.05). A main effect of blast-related would be an important step towards translational
mild TBI was observed on the threshold level. These and applied clinical use. Here we explore use of MEG
results demonstrate a distinct functional connectome (magnetoencephalography)-multivariate statistical
presentation associated with the presence of both learning analysis in identifying the neural features for
blast-related mild TBI and PTSD. These findings suggest differential PTSD/mTBI characterisation. Resting state
the possibility that blast-related mild TBI alterations in MEG-derived regional neural activity and coherence (or
functional brain connectomes affect the presentation functional connectivity) across seven canonical neural
or progression of recovery from PTSD. The current re- oscillation frequencies (delta to high gamma) were
sults offer mixed support for hyper-connectivity in the used. The selected features were consistent and largely
chronic phase of deployment TBI. confirmatory with previously established neurophysi-
ological markers for the two disorders. For regional
Keywords: PTSD, TBI, connectome, deployment, network power from theta, alpha and high gamma bands, the
amygdala, hippocampus and temporal areas were iden-
Journal of neurotrauma (2021), Vol. 38, No. 22 (34435885) tified. In line with regional activity, additional connec-
(4 citations) tions within the occipital, parietal and temporal regions
were selected across a number of frequency bands. This
study is the first to employ MEG-derived neural features
to reliably and differentially stratify the two disorders

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