Dynamic Cortical Connectivity during General Anesthesia in Surgical Patients

Area of Science:

• Neuroscience
• Anesthesiology
• Brain Imaging

Background:

• Cortical functional connectivity is theorized to be crucial for consciousness and the effects of anesthesia.
• However, the specific patterns of functional connectivity during surgery and general anesthesia remain largely uncharacterized.
• This study investigated the relationship between disrupted cortical connectivity and surgical anesthesia.

Purpose of the Study:

• To investigate functional connectivity patterns during general anesthesia and surgery.
• To test the hypothesis that disrupted cortical connectivity correlates with surgical anesthesia.

Main Methods:

• Fifty-three surgical patients were enrolled, with wireless electroencephalographic (EEG) data collected throughout the perioperative period.
• Functional connectivity was quantified using the weighted phase lag index (wPLI).
• Markov chain analysis characterized the temporal dynamics and state transitions of connectivity during anesthetic maintenance.

Main Results:

• While alpha frontal-parietal connectivity showed no significant changes compared to baseline, significant increases in alpha and theta prefrontal-frontal connectivity were observed during anesthetic maintenance.
• Theta frontal-parietal connectivity also significantly increased.
• Structured, non-random shifts between states of high prefrontal-frontal connectivity and suppressed frontal-parietal connectivity, and vice versa, were identified.

Conclusions:

• Functional connectivity patterns exhibit dynamic and structured transitions during surgery and general anesthesia.
• These findings suggest that a single measure of functional connectivity may not reliably serve as a correlate for surgical anesthesia.
• The structured nature of these shifts provides new insights into brain dynamics under anesthesia.