Brain Functional Connectivity as Biomarker for Propofol-Induced Alterations of Consciousness
Summary
Electroencephalography (EEG) functional connectivity (FC) reliably tracks anesthesia-induced loss of consciousness. This study shows EEG-based FC accurately distinguishes brain states during propofol sedation and recovery.
Area of Science:
- Neuroscience
- Anesthesiology
- Signal Processing
Background:
- Understanding consciousness and its alterations is a major challenge in neuroscience.
- Reliable markers for tracking anesthesia-induced loss of consciousness are lacking.
- Propofol sedation alters brain network dynamics, necessitating objective monitoring.
Purpose of the Study:
- To evaluate the utility of electroencephalogram (EEG)-based functional connectivity (FC) in characterizing brain network changes during propofol sedation.
- To identify reliable markers for altered states of consciousness induced by anesthesia.
Main Methods:
- Utilized a dataset of 21-channel scalp EEG recordings during propofol sedation.
- Estimated functional connectivity (FC) using the debiased Weighted Phase Lag Index (dWPLI2) across five EEG sub-bands.
- Employed a random subspace ensemble classifier with 18 functional connections for state discrimination.
Main Results:
- Significantly higher alpha band FC was observed during baseline, sedation, and recovery stages.
- Propofol sedation was associated with altered frontal brain activity and inhibited frontal connections.
- The classifier achieved 98.75% cross-validation accuracy in distinguishing sedation states.
Conclusions:
- EEG-based functional connectivity is a reliable method for distinguishing altered conscious states during anesthesia.
- Specific patterns of altered FC, particularly in the alpha band and frontal networks, characterize propofol-induced sedation.
- This approach offers a promising tool for objective monitoring of consciousness during anesthetic procedures.
