[Neurophysiological correlates of postoperative cognitive disorders]

Area of Science:

• Neuroscience
• Cardiovascular Surgery
• Cognitive Disorders

Background:

• Postoperative cognitive dysfunction (POCD) is a significant concern in patients undergoing cardiovascular procedures.
• Understanding the neurological underpinnings of POCD after coronary artery bypass grafting (CABG) is crucial for patient outcomes.

Purpose of the Study:

• To investigate the electroencephalogram (EEG) patterns of beta-2 activity associated with POCD in patients following CABG.
• To identify specific EEG correlates of cognitive dysfunction in the postoperative period.

Main Methods:

• Sixty patients undergoing CABG were assessed using neuropsychological tests before surgery and 7-10 days post-CABG.
• Resting-state EEG with eyes closed was recorded in 62 leads.
• Data analysis involved advanced statistical processing, including data clustering with a minimax criterion.

Main Results:

• Patients with POCD exhibited higher pre- and postoperative beta-2 rhythm power (20-30 Hz) compared to those without cognitive impairment.
• POCD was associated with elevated preoperative beta-2 activity in the right frontal cortex and reduced activity in left parietal areas post-CABG.
• Stable patient clustering based on beta-2 power correlated with better cognitive status.

Conclusions:

• Specific beta-2 activity patterns in the brain are correlated with POCD after CABG.
• Preoperative right frontal beta-2 power increases and postoperative left parietal decreases are indicators of low cognitive status.
• The developed classification method for beta-2 rhythm power demonstrates good discriminant ability for assessing cognitive status.