Analyzing the Loss and the Recovery of Consciousness: Functional Connectivity Patterns and Changes in Heart Rate...

Area of Science:

• Neuroscience
• Anesthesiology
• Autonomic Neuroscience

Background:

• General anesthesia (GA) profoundly affects central (CNS) and autonomic (ANS) nervous systems, altering consciousness.
• Understanding these neural processes is crucial for optimizing anesthetic management and patient safety.

Purpose of the Study:

• To analyze CNS and ANS activity during propofol-induced GA in patients undergoing spinal surgery.
• To investigate changes in electroencephalogram (EEG) signals and heart rate variability (HRV) across different anesthetic stages.

Main Methods:

• Pilot study involving 11 patients undergoing spinal surgery under propofol GA.
• EEG spectral and connectivity analyses were performed.
• HRV analysis was conducted during baseline, induction, loss of consciousness, and recovery phases.

Main Results:

• EEG showed decreased posterior alpha/beta power and increased delta power during induction.
• Anesthesia altered EEG connectivity, rebalancing short- and long-range cortical connections.
• HRV analysis revealed decreased complexity, increased regularity, bradycardia, and altered sympathetic/parasympathetic modulation.

Conclusions:

• Propofol-induced GA significantly modifies EEG signals and cardiac autonomic function.
• These changes suggest complex interactions between the CNS and ANS in modulating consciousness.
• Findings offer insights into neural mechanisms underlying anesthesia and consciousness.