Emerging Role of Electroencephalographic Aperiodic Activity in Anesthesia: A Narrative Review

Perioperative electroencephalography (EEG) has been widely studied in the last decade, not only as a useful brain state monitor but also as a potential tool to identify vulnerable patients at risk of perioperative neurocognitive disorders. Current literature has mostly focused on the oscillatory components of the EEG signal. Recently, interest in the functional role of the aperiodic activity of the EEG signal has increased both in neuroscience and in anesthesiology. This narrative review aims to provide clinicians and researchers with practical and methodologic insights into characterizing aperiodic EEG activity, focusing on its neurophysiological significance in neuroscience and anesthesia. It furthermore provides the reader with observed variations of aperiodic activity and periodic activity during general anesthesia and highlights whether those parameters could be useful to infer cognitive frailty and perioperative neurocognitive disorders and monitor depth of anesthesia during surgery.