Gender differences in quantitative EEG volumetric analysis shortly after sport concussion injury in high school athletes

Abstract

BackgroundStudies have identified gender differences in the incidence, severity and recovery time from sport concussion injury, all increased in females. The objective of this investigation is to explore gender differences in volumetric QEEG analysis after sport concussion injury in high school athletes.MethodsStandard electroencephalograms (EEGs) were analyzed in 40 high school athletes (20 males) shortly after concussion injury using sLORETA imaging compared to a normative database (NYU/BrainDx). Peak Z-score variation (PZV), and %volume of grey matter activity that fell outside Z = −2.5 to 2.5 (PIGMV for increased activity, PRGMV for reduced) were calculated for each of 5 EEG frequency bands.ResultsPZV was increased in the Delta/Theta/Alpha, in both genders with no statistical gender difference (M/F averages: 3.82/3.16, 2.73/2.72, 2.52/2.72, respectively, p ≥ 0.05), Beta in females not males, Beta-Gamma in males and females which was significantly increased in females (M/F averages: 1.75/2.88, 3.64/5.02 respectively, p < 0.01). PZV was decreased in Beta in males not females (M/F averages: −2.83/−2.18, p = 0.05) there was a significant difference in reduced beta-gamma activity (M/F averages: −1.11/−0.49, p = 0.01). Greater than 1% grey matter volume of PIGMV was seen in Delta/Theta/Alpha/Beta activity with no gender difference (M/F averages: 20.94/11.71, 5.87/7.38, 5.62/7.93, 4.09/9.22 p ≥ 0.05). There was a significant difference in PIGMV in Beta-Gamma (M/F averages: 31.94/60.04, p = 0.01). Greater than 1% PRGMV in Alpha/Beta in both genders and Theta activity in females not males.ConclusionsSlower frequency (Delta, Theta, and Alpha) abnormal variations show no statistical gender differences. In the faster frequency bands (Beta and Beta-Gamma), females demonstrate a larger variation from the norm and larger percent grey matter volume affected by increased Beta and Beta-Gamma activity. Males, not females exhibit a deficiency in Beta activity after concussion. Further research to correlate these electrophysiologic changes with symptom severity and recovery time is needed.