EEG spectral findings in healthy, elderly men and women--sex differences

Computerized spectral analysis of the EEG was performed in 119 healthy, elderly men and women, ranging in age from 60 to 87 years with an x age of 70.4 years, to evaluate gender-related variance. The groups did not differ in age, education levels or Folstein score. We compared the parasagittal derivations in men (n = 53) to women (n = 66), controlling for the effect of age by decade. Compared to men, women had a significant (usually P < 0.01) increase in the parasagittal mean frequency (1-30 Hz and 4-20 Hz), beta 1 and beta 2, while alpha 2 and theta-beta were decreased. Mean frequency did not differ significantly by decade, nor were there significant sex-age interactions. Our results extend previous EEG spectral findings to older, healthy, elderly subjects. Although the basis for the gender-related differences is uncertain, we suggest that quantitative EEGs establish gender-based norms in elderly adults.