Reduced prefrontal MEG alpha-band power in mild traumatic brain injury with associated posttraumatic stress disorder symptoms

Popescu, Mihail; Hughes, John D.; Popescu, Elena-Anda; Riedy, Gerard; DeGraba, Thomas J.

doi:10.1016/j.clinph.2016.06.004

Cited by 18 publications

(14 citation statements)

References 73 publications

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“…This finding was in line with that of another study with rs-fMRI, which showed significantly decreased ALFFs in the SFG of mTBI patients compared with those in the SFG of HCs [38]. Popescu and colleagues’ analysis of MEG data showed that the power of the alpha band in the SFG was generally lower in mTBI patients than in HCs, and the changes in alpha-band power were negatively associated with scores reflecting symptoms of emotional numbing [34]. All these studies supported the idea that the left MFG is an important part of information processing and can coordinate working memory (e.g., short-term memory) and other sources of information that are particularly important for attention and emotional maintenance [39].…”

Section: Discussionsupporting

confidence: 88%

“…Dall et al demonstrated increased thickness within the PFC regions and weak correlations between the amount of PFC thickening and cognitive performance in chronic mTBI patients [31]. Popesccu et al indicated that mTBI patients showed reduced alpha-band power in the bilateral MFG by using resting-state MEG, and the alpha-band power in the MFG was negatively correlated with scores reflecting symptoms of emotional numbing [34]. Therefore, all related studies have suggested that the PFC, specifically the MFG, might be an important part of cognitive and emotional regulation circuits; changes in this region may be associated with characteristic symptoms of cognitive impairment.…”

Section: Discussionmentioning

confidence: 99%

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Disrupted brain functional hub and causal connectivity in acute mild traumatic brain injury

Chen

et al. 2019

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There have been an increasing number of functional magnetic resonance imaging (fMRI) reports on brain abnormalities in mild traumatic brain injury (mTBI) at different phases. However, the neural bases and cognitive impairment after acute mTBI are unclear. This study aimed to identify brain functional hubs and connectivity abnormalities in acute mTBI patients and their correlations with deficits in cognitive performance. Within seven days after brain injury, mTBI patients (n=55) and age-, sex-, and educational -matched healthy controls (HCs) (n=41) underwent resting-state fMRI scans and cognitive assessments. We derived functional connectivity (FC) strength of the whole-brain network using degree centrality (DC) and performed Granger causality analysis (GCA) to analyze causal connectivity patterns in acute mTBI. Compared with HCs, acute mTBI patients had significantly decreased network centrality in the left middle frontal gyrus (MFG). Additionally, acute mTBI showed decreased inflows from the left MFG to bilateral middle temporal gyrus (MTG), left medial superior frontal gyrus (mSFG), and left anterior cingulate cortex (ACC). Correlation analyses revealed that changes in network centrality and causal connectivity were associated with deficits in cognitive performance in mTBI. Our findings may help to provide a new perspective for understanding the neuropathophysiological mechanism of acute cognitive impairment after mTBI.

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Section: Discussionsupporting

confidence: 88%

Section: Discussionmentioning

confidence: 99%

Disrupted brain functional hub and causal connectivity in acute mild traumatic brain injury

Chen

et al. 2019

Aging

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“…Furthermore, one study observed a persistent reduction of resting alpha power in multi-concussion athletes tested at 12 months post-injury (Gosselin, et al, 2009). However, no clear EEG or time-frequency features seem specific to mTBI or SRC, especially beyond the acute post-injury phase (Nuwer, et al, 2005;Popescu, Hughes, Popescu, Riedy, & DeGraba, 2016).…”

Section: Introductionmentioning

confidence: 99%

Electrophysiological impact of multiple concussions in asymptomatic athletes: A re-analysis based on alpha activity during a visual-spatial attention task

et al. 2018

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Most EEG studies used event-related potentials to assess long-term and cumulative effects of sport-related concussions on brain activity. Time-frequency methods provide another approach that allows the detection of subtle shifts in types and patterns of brain oscillations. We sought to discover whether event-related alpha activity would be significantly affected in asymptomatic multi-concussed athletes. We measured the amplitude of alpha activity (8-12Hz) from the EEG recorded during a visual-spatial attention task to compare event-related alpha perturbations in 13 multi-concussed athletes and 14 age-equivalent, non-concussed teammates. Relative to non-concussed athletes, multi-concussed athletes showed significantly less event-related perturbations time-locked to stimulus presentation. Alpha activity alterations were closely related to the number of concussions sustained. Event-related alpha activity differed in asymptomatic multi-concussed athletes when compared to controls. Our study suggests that low-level neurophysiological underpinnings of the deployment of visual-spatial attention are affected in multi-concussed athletes even though their last concussion occurred on average 30 months prior to testing.

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“…A reduced rate of transitions among attractor states has been suggested as a characteristic of brain dysfunction in TBI (Hellyer et al, 2015). Reductions in cortical activity may be observed in resting state or during task performance, may be broadband or manifested in specific frequency ranges, and may predispose to other common post-concussive symptoms in mTBI (Popescu et al, 2016). …”

Section: Discussionmentioning

confidence: 99%

Activation of dominant hemisphere association cortex during naming as a function of cognitive performance in mild traumatic brain injury: Insights into mechanisms of lexical access

Popescu

Hughes

Popescu

et al. 2017

NeuroImage: Clinical

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Patients with a history of mild traumatic brain injury (mTBI) and objective cognitive deficits frequently experience word finding difficulties in normal conversation. We sought to improve our understanding of this phenomenon by determining if the scores on standardized cognitive testing are correlated with measures of brain activity evoked in a word retrieval task (confrontational picture naming). The study participants (n = 57) were military service members with a history of mTBI. The General Memory Index (GMI) determined after administration of the Rivermead Behavioral Memory Test, Third Edition, was used to assign subjects to three groups: low cognitive performance (Group 1: GMI ≤ 87, n = 18), intermediate cognitive performance (Group 2: 88 ≤ GMI ≤ 99, n = 18), and high cognitive performance (Group 3: GMI ≥ 100, n = 21). Magnetoencephalography data were recorded while participants named eighty pictures of common objects. Group differences in evoked cortical activity were observed relatively early (within 200 ms from picture onset) over a distributed network of left hemisphere cortical regions including the fusiform gyrus, the entorhinal and parahippocampal cortex, the supramarginal gyrus and posterior part of the superior temporal gyrus, and the inferior frontal and rostral middle frontal gyri. Differences were also present in bilateral cingulate cortex and paracentral lobule, and in the right fusiform gyrus. All differences reflected a lower amplitude of the evoked responses for Group 1 relative to Groups 2 and 3. These findings may indicate weak afferent inputs to and within an extended cortical network including association cortex of the dominant hemisphere in patients with low cognitive performance. The association between word finding difficulties and low cognitive performance may therefore be the result of a diffuse pathophysiological process affecting distributed neuronal networks serving a wide range of cognitive processes. These findings also provide support for a parallel processing model of lexical access.

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Reduced prefrontal MEG alpha-band power in mild traumatic brain injury with associated posttraumatic stress disorder symptoms

Cited by 18 publications

References 73 publications

Disrupted brain functional hub and causal connectivity in acute mild traumatic brain injury

Disrupted brain functional hub and causal connectivity in acute mild traumatic brain injury

Electrophysiological impact of multiple concussions in asymptomatic athletes: A re-analysis based on alpha activity during a visual-spatial attention task

Activation of dominant hemisphere association cortex during naming as a function of cognitive performance in mild traumatic brain injury: Insights into mechanisms of lexical access

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