Neural circuitry of PTSD with or without mild traumatic brain injury: A meta-analysis
ABSTRACT Posttraumatic Stress Disorder (PTSD) and mild traumatic brain injury (mTBI) often occur together. Parsing out the unique and overlapping effects of these conditions on the brain, can inform the selection of appropriate treatments. Although recent studies indicate that warfighters in Operations Enduring and Iraqi Freedom are at a high risk for PTSD and mTBI, there is a dearth of research directly comparing their neural correlates. In this paper, we briefly discuss these conditions and supply two meta-analyses of the relevant functional magnetic resonance imaging studies conducted to date. By looking at the overlap in these analyses, we suggest that the middle frontal gyrus may be an appropriate area for future investigations aimed at disentangling PTSD and mTBI. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
SourceAvailable from: dept.psych.columbia.edu
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ABSTRACT: Social anxiety disorder (SAD) is one of the most frequent anxiety disorders. The landmark meta-analysis of functional neuroimaging studies by Etkin & Wager (2007) revealed primarily the typical fear circuit as overactive in SAD. Since then, new methodological developments such as functional connectivity and more standardized structural analyses of grey and white matter have been developed. We provide a comprehensive update and a meta-analysis of neuroimaging studies in SAD since 2007 and present a new model of the neurobiology of SAD. We confirmed the hyperactivation of the fear circuit (amygdala, insula, anterior cingulate and prefrontal cortex) in SAD. In addition, task-related functional studies revealed hyperactivation of medial parietal and occipital regions (posterior cingulate, precuneus, cuneus) in SAD and a reduced connectivity between parietal and limbic and executive network regions. Based on the result of this meta-analysis and review, we present an updated model of SAD adopting a network-based perspective. The disconnection of the medial parietal hub in SAD extends current frameworks for future research in anxiety disorders.Neuroscience & Biobehavioral Reviews 11/2014; 47:260-280. DOI:10.1016/j.neubiorev.2014.08.003 · 10.28 Impact Factor
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ABSTRACT: Posttraumatic stress disorder (PTSD) is common among combat personnel with mild traumatic brain injury (mTBI). While patients with either PTSD or mTBI share abnormal activation of multiple frontal brain areas, anterior cingulate cortex (ACC) activity during inhibitory processing may be particularly affected by PTSD. To further test this hypothesis, we recorded electroencephalography from 32 combat veterans with mTBI—17 of whom were also comorbid for PTSD (mTBI+PTSD) and 15 without PTSD (mTBI-only). Subjects performed the Stop Task, a validated inhibitory control task requiring inhibition of initiated motor responses. We observed a larger inhibitory processing eventrelated potential (ERP) in veterans with mTBI+PTSD, including greater N200 negativity. Furthermore, greater N200 negativity correlated with greater PTSD severity. This correlation was most dependent on contributions from the dorsal ACC. Support vector machine analysis demonstrated that N200 and P300 amplitudes objectively classified veterans into mTBI-only or mTBI+PTSD groups with 79.4% accuracy. Our results support a model where, in combat veterans with mTBI, larger ERPs from cingulate areas are associated with greater PTSD severity and likely related to difficulty controlling ongoing brain processes, including trauma-related thoughts and feelings.Psychiatry Research Neuroimaging 10/2014; 224(1). DOI:10.1016/j.pscychresns.2014.07.010 · 2.83 Impact Factor