Resting EEG partial coherence demonstrates increased γ range central functional connectivity in amnestic mild cognitive impairment

Authors: Ioannis Vlachos, Ch. Moschovos, L. Apostolakopoulou, K. Karasavvidou, E. Ntanasi, E. Mamalaki, D. Kugiumtzis, V. K. Kimiskidis, N. Scarmeas, A. Kyrozis
Publication year: 2025
Publication type: Článek v odborném periodiku
Periodical: Brain Research
Bibliographic citation: VLACHOS, Ioannis, MOSCHOVOS, Ch., APOSTOLAKOPOULOU, L., KARASAVVIDOU, K., NTANASI, E., MAMALAKI, E., KUGIUMTZIS, D., KIMISKIDIS, V. K., SCARMEAS, N., KYROZIS, A. Resting EEG partial coherence demonstrates increased γ range central functional connectivity in amnestic mild cognitive impairment. Brain Research. 2025, 1867(November 2025), 149973. ISSN 0006-8993. E-ISSN 1872-6240
Dostupné z: doi:10.1016/j.brainres.2025.149973.
DOI: 10.1016/j.brainres.2025.149973
ID: 641461
Online record: View online record

Abstract

OBJECTIVE: Relatively little is known about EEG high gamma (gamma) range changes in Alzheimer's disease (AD). We investigated functional connectivity, focusing on the gamma range, in amnestic Mild Cognitive Impairment (MCI) using ordinary Coherence (COH) and Partial Coherence (PCOH), a metric which enhances signal-to-noise ratio at high frequencies. METHODS: MCI (N=21) and Cognitively Normal (CN, N=62) ALBION study participants had resting EEG with eyes closed (EC) and eyes open (EO) in 10/20 montage (19 active electrodes). COH and PCOH in 0.5-100 Hz for each subject were calculated for all 171 electrode pairs. RESULTS: In both gamma1 (30-50 Hz) and gamma2 (50-100 Hz) ranges, PCOH was significantly higher in MCI than in CN in several electrode pairs, especially centrally, in both eye conditions. Concerning local (average of each electrode) connectivity, MCI compared to CN showed significantly higher values in PCOH centrally. CONCLUSIONS: Resting EEG gamma range functional connectivity at central areas, as revealed by PCOH, is significantly higher in MCI than in CN. SIGNIFICANCE: Gamma range local and regional EEG functional connectivity differences may help construct useful and easily available biomarkers in neurodegeneration. Metrics such as PCOH, which factor out global connectivity components, may help reveal such differences.