To explore characteristics of volumetric quantitative EEG (QEEG) analysis and relationships with cognitive performance after sport concussion injury in high school athletes.

Electroencephalograms (EEGs) were recorded in 60 high school athletes (30 males) shortly after concussion injury, analysis using sLORETA imaging normative database comparisons (NYU/BrainDx). Peak Z-score variation for scores for positive and negative Z-scores (PZV Max, PZV Min), and Percent Volume Grey Matter activity falling outside Z= -2.5 to 2.5 (PRGMV, PIGMV) were calculated for five frequency bands. Data were compared for correlations to computerized neurocognitive assessment (XLNTbrain). Correlations between sLORETA Regions of Interest (ROI) and XLNTbrain performance were performed.

PZV was increased (Z>2.5) in all bands. Deficiencies (Z<-2.5) were not seen. Average PIGMV  was maximal in beta-gamma (53%) and delta (14%).

Gender differences were found: PZV Max in beta-gamma (F>M, p=.005),  PZV Min in beta and beta-gamma (M>F, p=.03, p=.007), PIGMV  in beta-gamma (F>M 64% vs.39%, p=.002), and PRGMV in beta (M>F, 5.9% vs. 2.1%, p=.045).

Correlations with cognitive testing demonstrated two relationships: dysfunctional (greater deregulation associated with greater impairment), and compensatory (greater deregulation associated with better performance). Significant task/region specific dysfunctional correlations were seen in all bands except alpha. Significant compensatory correlations were only seen in alpha.

1. sLORETA demonstrates broad spectrum EEG deregulation in high school aged athletes soon after concussion
2. This deregulation is predominantly an increase in current source density amplitude
3. There are significant gender differences in this deregulation: Females demonstrate significantly greater beta-gamma increase. Males demonstrate greater beta deficiency.
4. This deregulation persists beyond clinical resolution of the concussion.
5. There are significant correlations between sLORETA deregulation and  computerized neurocognitive performance: dysfunctional correlations seen in all bands except for alpha, compensatory correlations only seen in the alpha band.