Electroencephalogram alpha asymmetry in geriatric depression : Valid or vanished?

Abstract

A correlation between asymmetry in electroencephalographs (EEG) and depression has been demonstrated in many studies. To the best of our knowledge there are no studies including oldest old geriatric patients. The objective of this study was to evaluate whether frontal and parietal alpha asymmetry can be used to differentiate between depressed and control patients in a cohort sample with amean age of 80years. Differences in the EEG were investigated in 39 right-handed female geriatric patients (mean age 80years) with respect to frontal alpha asymmetry (FAA) and parietal alpha asymmetry (PAA) in depression (n= 14), depression combined with anxiety (n= 11) and normal controls (n= 14) as assessed with the hospital anxiety and depression scale (HADS). Band power was calculated for alpha1 (6.9-8.9Hz), alpha2 (8.9-10.9Hz) and alpha3 bands (10.9-12.9Hz). Furthermore, correlations between frontal and parietal alpha asymmetry and the geriatric depression scale (GDS), the HADS and the mini mental state examination (MMSE) were calculated. A differentiation between the three groups was not possible with FAA and PAA. Significant correlations were found between PAA alpha3 band and anxiety and depression. The alpha asymmetry in EEG seemed to disappear with age. Correlations between PAA and anxiety and depression were found. The results are in line with the right (hemisphere) hemi-aging hypothesis.