Age-specific electroencephalography dynamics during anesthesia: monitoring and neurocognitive implications
10.17085/apm.25375
- Author:
Young SONG
- Publication Type:Review
- From:Anesthesia and Pain Medicine
2025;20(4):289-300
- CountryRepublic of Korea
- Language:English
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Abstract:
Electroencephalography (EEG) reflects thalamocortical activity during anesthesia; however, its signatures are strongly dependent on age. Children exhibit evolving oscillatory patterns, whereas older patients show attenuated alpha power and greater burst suppression (BS). As most processed EEG (pEEG) algorithms were derived largely from adult data, their reliability is limited in very young and older patients. This narrative review summarizes age-specific EEG dynamics under γ-aminobutyric acid (GABA)-ergic anesthesia, focusing on developmental and aging trajectories, the impact of age on pEEG indices, and the associations of EEG features with postoperative delirium (POD), emergence agitation (EA), and recovery outcomes. Evidence from randomized trials of pEEG- and spectrogram- or raw EEG-guided anesthesia is also reviewed. The most prominent age-related difference in anesthetic EEG is observed in frontal alpha oscillations, which emerge in late infancy, peak in childhood, and decline with age; this trajectory is considered the main driver of bias in pEEG outputs. In infants and toddlers, indices often remain elevated despite deep anesthesia. In children aged up to 6–7 years, values are highly variable and show a weak correlation with anesthetic concentration, limiting the reliability of the threshold. In older adults, alpha attenuation and spectral flattening elevate the index values, even during suppression, thereby increasing the risk of overdose. Age-related biases may also influence clinical outcomes. Although the evidence is mixed, meta-analyses have indicated that pEEG-guided or lighter anesthesia can modestly reduce POD. However, pEEG guidance has not consistently reduced the incidence of EA in children. Reduced alpha power and greater BS consistently predict POD in adults, although evidence on pediatric neurocognitive outcomes remains limited. Spectrogram- or raw EEG-guided titration shows variable neurocognitive outcomes, and anesthetic-sparing effects have not been consistent across trials. pEEG reliability declines in young and older patients. Age-adjusted interpretation, with attention paid to raw EEG and spectrograms, is essential for safer titration and improved neurocognitive outcomes.
