Brain activation profiles in mTBI: Evidence from combined resting-state EEG and MEG activity

Abstract

In this study, we compared the brain activation profiles obtained from resting state Electroencephalographic (EEG) and Magnetoencephalographic (MEG) activity in six mild traumatic brain injury (mTBI) patients and five orthopedic controls, using power spectral density (PSD) analysis. We first estimated intracranial dipolar EEG/MEG sources on a dense grid on the cortical surface and then projected these sources on a standardized atlas with 68 regions of interest (ROIs). Averaging the PSD values of all sources in each ROI across all control subjects resulted in a normative database that was used to convert the PSD values of mTBI patients into z-scores in eight distinct frequency bands. We found that mTBI patients exhibited statistically significant overactivation in the delta, theta, and low alpha bands. Additionally, the MEG modality seemed to better characterize the group of individual subjects. These findings suggest that resting-state EEG/MEG activation maps may be used as specific biomarkers that can help with the diagnosis of and assess the efficacy of intervention in mTBI patients.

Altered Rich-Club and Frequency-Dependent Subnetwork Organization in Mild Traumatic Brain Injury: A MEG Resting-State Study

“…Given our previous use of connectivity analysis to study mTBI using Granger causality (Zouridakis et al, 2012 ), phase synchronization (Dimitriadis et al, 2015b ), and cross-frequency coupling (Antonakakis et al, 2015 , 2016 ) of spontaneous MEG, as well as brain activation patterns of both EEG and MEG at the sensor (Li et al, 2015 ) and source (Zouridakis et al, 2016 ; Li et al, 2017 ) levels, an obvious question is whether the possible presence of an RC organization could provide some complementary features to the SW organization that is typically seen in mTBI FCGs. Thus, in the present study, we hypothesize that exploring brain connectivity network models derived from spontaneous MEG activity using estimators for both intra and cross-frequency couplings (Buzsáki and Watson, 2012 ) would help identify meaningful network topological features in compromised mTBI brain networks that could be used as guideline biomarkers for validating the recovery from mTBI (Bharath et al, 2015 ).…”

Magnetoencephalography in the Detection and Characterization of Brain Abnormalities Associated with Traumatic Brain Injury: A Comprehensive Review

“…Finally, MEG can also be combined with EEG to characterize activity in the brain associated with TBI. In 2015, Li et al published a study in which they analyzed resting-state MEG and EEG activity at 68 brain regions of interest [38]. Comparing brain activation maps between patients with mild TBI and controls, they found significant differences in low-frequency activity on both EEG and MEG.…”

Language impairments and resting-state EEG in brain tumour patients: Revealing connections

“…Patients with traumatic brain injury demonstrate increased activation in the delta and theta frequency bands (Haneef, Levin, Frost, & Mizrahi, 2013;Li et al, 2015;Thatcher, 2006). Increased theta activity is an indicator of poorer language performance, evidenced by a higher number of stimulus cues given in an object naming task.…”