Salivary testosterone and EEG spectra of 9- to 11-year-old male children.

Although most investigators agree that there are electroencephalogram (EEG) changes with chronological age around puberty, no one has remarked on why this is so. As the increase in testosterone at the end of prepubertal childhood is a biomarker for the on-set of a period of accelerated growth and development, we searched for an association between testosterone level and the spectral power and topography of EEG. We tested 60 children between 9- and 11-years-old, each demonstrating normal neurological examination and Wechsler intelligence scale over 90. Salivary testosterone was measured using immunoenzymatic chemiluminescent assay. Children were divided into 3 groups according to measured testosterone level. EEG was processed with a Fast Fourier Transform; average of relative power spectral analyses were calculated and data divided into delta, theta, alpha, and beta bands. The principal finding was the highly significant interaction between EEG band and testosterone group, F(6, 171) = 4.54, Huynh-Feldt epsilon = 0.853, p =.001. Delta relative power decreased significantly and Alpha relative power increased significantly in the 2 groups with higher salivary testosterone concentration when compared to the lowest testosterone group. This work suggests that increased testosterone in prepubertal children can predict some of the same EEG changes that are usually associated with increased chronological age.