Alpha asymmetry in QEEG recordings in young patients with anxiety

Abstract

Anxiety is defined as a subjective sense of worry, apprehension, fear and distress. When severe, it can affect a child's thinking, decision-making ability, perceptions of the environment, learning and concentration. Basal instability in cortical arousal, as reflected in measures of quantitative electroencephalography (qEEG), is common in most of the anxiety disorders.

Subjects and methods: The sample was composed of 26 children and teenagers aged 11.73±4.03 years, F:M=1:2. The group was diagnosed as having Generalized Anxiety Disorder (GAD). EEG was recorded with Quantitative EEG equipment--Mitsar-amplifier[with 19 electrodes with 250 Hz sampling rate in the 0.3-70 Hz frequency range in the following conditions: eyes opened and eyes closed, at least 5 minutes each.

Results and conclusions: A statistically significant difference of spectra power in alpha band between left and right hemisphere was obtained. The right frontal asymmetry is specific to the right-handed. In eyes-open condition the percentage of children manifesting right asymmetry is up to 92.31% and in the eyes-closed condition it is 88.46%. Left frontal asymmetry was typical of left-handed children. We did not confirm the posterior right asymmetry suggested by other authors. The correlations between asymmetry and hand preference of children was very strong (r=0.68-0.85) and statistically significant (p<0.05) only for frontal regions of the brain. For parietal regions this was weak and statistically not significant.