RT Journal Article
SR Electronic
T1 Alterations in the Magnetoencephalography Default Mode Effective Connectivity following Concussion
JF American Journal of Neuroradiology
JO Am. J. Neuroradiol.
FD American Society of Neuroradiology
DO 10.3174/ajnr.A7232
A1 D.D. Reddy
A1 E.M. Davenport
A1 F.F. Yu
A1 B. Wagner
A1 J.E. Urban
A1 C.T. Whitlow
A1 J.D. Stitzel
A1 J.A. Maldjian
YR 2021
UL http://www.ajnr.org/content/early/2021/09/09/ajnr.A7232.abstract
AB BACKGROUND AND PURPOSE: Magnetoencephalography is sensitive to functional connectivity changes associated with concussion. However, the directional influences between functionally related regions remain unexplored. In this study, we therefore evaluated concussion-related magnetoencephalography-based effective connectivity changes within resting-state default mode network regions.MATERIALS AND METHODS: Resting-state magnetoencephalography was acquired for 8 high school football players with concussion at 3 time points (preseason, postconcussion, postseason), as well as 8 high school football players without concussion and 8 age-matched controls at 2 time points (preseason, postseason). Time-series from the default mode network regions were extracted, and effective connectivity between them was computed for 5 different frequency bands. The default mode network regions were grouped into anterior and posterior default mode networks. The combined posterior-to-anterior and anterior-to-posterior effective connectivity values were averaged to generate 2 sets of values for each subject. The effective connectivity values were compared using a repeated measures ANOVA across time points for the concussed, nonconcussed, and control groups, separately.RESULTS: A significant increase in posterior-to-anterior effective connectivity from preseason to postconcussion (corrected P value = .013) and a significant decrease in posterior-to-anterior effective connectivity from postconcussion to postseason (corrected P value = .028) were observed in the concussed group. Changes in effective connectivity were only significant within the delta band. Anterior-to-posterior connectivity demonstrated no significant change. Effective connectivity in the nonconcussed group and controls did not show significant differences.CONCLUSIONS: The unidirectional increase in effective connectivity postconcussion may elucidate compensatory processes, invoking use of posterior regions to aid the function of susceptible anterior regions following brain injury. These findings support the potential value of magnetoencephalography in exploring directional changes of the brain network following concussion.ECeffective connectivityEEGelectroencephalographyDMNdefault mode networkFCfunctional connectivityGCGranger causalityMEGmagnetoencephalographymTBImild traumatic brain injury