Citation

Huang M, Harrington DL, Robb A, Angeles A, Nichols S, Drake AI, Song T, Diwakar M, Huang CW, Risbrough V, Dale AM, Bartsch H, Matthews S, Huang JW, Lee RR, Baker DG. J. Neurotrauma 2016; 34(7): 1412-1426.

Affiliation

VA San Diego Healthcare System, Psychiatry, San Diego, California, United States ; dgbaker@ucsd.edu.

Copyright

(Copyright © 2016, Mary Ann Liebert Publishers)

DOI

10.1089/neu.2016.4581

PMID

27762653

Abstract

Blast mild traumatic brain injury (mTBI) is a leading cause of sustained impairment in military service members and Veterans. However, the mechanism of persistent disability is not fully understood. The present study investigated disturbances in brain functioning in mTBI participants using a source-imaging-based approach to analyze functional connectivity (FC) from resting-state magnetoencephalography (rs-MEG). Study participants included 26 active-duty service members or Veterans who had blast mTBI with persistent post-concussive symptoms and 22 healthy control active-duty service members or Veterans. The source time-courses from regions of interest (ROIs) were used to compute ROI to whole-brain (ROI-global) FC for different frequency bands using two different measures: 1) time-lagged cross-correlation and 2) phase-lock synchrony. Compared with the controls, blast mTBI participants showed increased ROI-global FC in beta, gamma, and low-frequency bands, but not in the alpha band. Sources of abnormally increased FC included the: 1) prefrontal cortex (right ventro-medial prefrontal cortex, right rostral anterior cingulate cortex), left ventro-lateral and dorsolateral prefrontal cortex; 2) medial temporal lobe (bilateral parahippocampus, hippocampus, and amygdala); and 3) right putamen and cerebellum. In contrast, the blast mTBI group also showed decreased FC of the right frontal pole. Group differences were highly consistent across the two different FC measures. FC of the left ventro-lateral prefrontal cortex correlated with executive functioning and processing speed in mTBI participants. Altogether, our findings of increased and decreased regional-patterns of FC suggest that disturbances in intrinsic brain connectivity may be due to multiple mechanisms and are associated with cognitive sequelae of the injury.

Language: en