title: Characterising intra- and inter-intrinsic network synchrony in combat-related post-traumatic stress disorder.
abstract: Soldiers with post-traumatic stress disorder (PTSD) exhibit elevated gamma-band synchrony in left fronto-temporal cortex, and connectivity measures in these regions correlate with comorbidities and PTSD severity, which suggests increased gamma synchrony is related to symptomology. However, little is known about the role of intrinsic, phase-synchronised networks in the disorder. Using magnetoencephalography (MEG), we characterised spectral connectivity in the default-mode, salience, visual, and attention networks during resting-state in a PTSD population and a trauma-exposed control group. Intrinsic network connectivity was examined in canonical frequency bands. We observed increased inter-network synchronisation in the PTSD group compared with controls in the gamma (30-80 Hz) and high-gamma range (80-150 Hz). Analyses of connectivity and symptomology revealed that PTSD severity was positively associated with beta synchrony in the ventral-attention-to-salience networks, and gamma synchrony within the salience network, but also negatively correlated with beta synchrony within the visual network. These novel results show that frequency-specific, network-level atypicalities may reflect trauma-related alterations of ongoing functional connectivity, and correlations of beta synchrony in attentional-to-salience and visual networks with PTSD severity suggest complicated network interactions mediate symptoms. These results contribute to accumulating evidence that PTSD is a complicated network-based disorder expressed as altered neural interactions.
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Canada; Neuroscience & Mental Health Program, The Hospital for Sick Children Research Institute, Toronto, Canada; Department of Medical Imaging, University of Toronto, Toronto, Canada. Electronic address: ben.dunkley@sickkids.ca.
authors.forename: Benjamin T
authors.initials: BT
authors.lastname: Dunkley
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Canada; Neuroscience & Mental Health Program, The Hospital for Sick Children Research Institute, Toronto, Canada; Department of Medical Imaging, University of Toronto, Toronto, Canada; Department of Psychology, University of Toronto, Toronto, Canada.
authors.forename: Sam M
authors.initials: SM
authors.lastname: Doesburg
authors.affiliation: Directorate of Mental Health, Canadian Forces Health Services, Ottawa, Canada.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Jetly
authors.affiliation: Directorate of Mental Health, Canadian Forces Health Services, Ottawa, Canada.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Sedge
authors.affiliation: Neuroscience & Mental Health Program, The Hospital for Sick Children Research Institute, Toronto, Canada; Division of Neurology, The Hospital for Sick Children, Toronto, Canada.
authors.forename: Elizabeth W
authors.initials: EW
authors.lastname: Pang
authors.affiliation: Department of Diagnostic Imaging, The Hospital for Sick Children, Toronto, Canada; Neuroscience & Mental Health Program, The Hospital for Sick Children Research Institute, Toronto, Canada; Department of Medical Imaging, University of Toronto, Toronto, Canada; Department of Psychology, University of Toronto, Toronto, Canada.
authors.forename: Margot J
authors.initials: MJ
authors.lastname: Taylor
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology; D001931:Brain Mapping / Q000379:methods; D003130:Combat Disorders / Q000175:diagnosis* / Q000378:metabolism* / Q000523:psychology; D006801:Humans; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D008889:Military Personnel / Q000523:psychology; D009415:Nerve Net / Q000378:metabolism*; D009434:Neural Pathways / Q000378:metabolism; D013313:Stress Disorders, Post-Traumatic / Q000175:diagnosis* / Q000378:metabolism* / Q000523:psychology
keywords: Functional connectivity; Intrinsic connectivity networks; Magnetoencephalography (MEG); Neural synchrony; Oscillations; Post-traumatic stress disorder; Resting-state; Soldiers