Neurophysiological connectomic signatures of consciousness during propofol-induced general anesthesia

General anesthesia induces reversible changes in consciousness through cortical activity and connectivity alterations, yet the functional connectome dynamics underlying propofol-induced unconsciousness remains unclear. We analyze high-density 128-channel electroencephalogram (EEG) from 31 surgical patients using source localization to identify neurobiological connectome signatures of propofol anesthesia. Propofol anesthesia increases delta and theta functional connectivity and decreases alpha, beta, and gamma connectivity. A classification model and dynamic analysis of consciousness loss reveals that alpha-band connectivity between parietal, occipital, and subcortical regions is critical for sustaining consciousness, with its disruption marking a key transition to unconsciousness. EEG from 46 additional patients under mild sedation with low-dose propofol confirms that decreased parietal-related alpha connectivity serves as a stable marker of reduced consciousness, insensitive to subtle fluctuations but sensitive to the transition from consciousness to unconsciousness. These findings suggest that parietal, occipital, and subcortical alpha connectivity serves as a reliable neural correlate of propofol-induced unconsciousness.