Resting State Alpha Electroencephalographic Rhythms Are Affected by Sex in Cognitively Unimpaired Seniors and Patients with Alzheimer's Disease and Amnesic Mild Cognitive Impairment: A Retrospective and Exploratory Study

Cereb Cortex. 2022 May 14;32(10):2197-2215. doi: 10.1093/cercor/bhab348.


In the present retrospective and exploratory study, we tested the hypothesis that sex may affect cortical sources of resting state eyes-closed electroencephalographic (rsEEG) rhythms recorded in normal elderly (Nold) seniors and patients with Alzheimer's disease and mild cognitive impairment (ADMCI). Datasets in 69 ADMCI and 57 Nold individuals were taken from an international archive. The rsEEG rhythms were investigated at individual delta, theta, and alpha frequency bands and fixed beta (14-30 Hz) and gamma (30-40 Hz) bands. Each group was stratified into matched females and males. The sex factor affected the magnitude of rsEEG source activities in the Nold seniors. Compared with the males, the females were characterized by greater alpha source activities in all cortical regions. Similarly, the parietal, temporal, and occipital alpha source activities were greater in the ADMCI-females than the males. Notably, the present sex effects did not depend on core genetic (APOE4), neuropathological (Aβ42/phospho-tau ratio in the cerebrospinal fluid), structural neurodegenerative and cerebrovascular (MRI) variables characterizing sporadic AD-related processes in ADMCI seniors. These results suggest the sex factor may significantly affect neurophysiological brain neural oscillatory synchronization mechanisms underpinning the generation of dominant rsEEG alpha rhythms to regulate cortical arousal during quiet vigilance.

Keywords: exact low-resolution brain electromagnetic source tomography (eLORETA); mild cognitive impairment due to Alzheimer’s disease (ADMCI); resting state electroencephalographic (rsEEG) rhythms; sex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alpha Rhythm / physiology
  • Alzheimer Disease* / psychology
  • Cerebral Cortex
  • Cognitive Dysfunction* / psychology
  • Electroencephalography / methods
  • Female
  • Humans
  • Male
  • Rest / physiology
  • Retrospective Studies