In the Literature

Summary of "Association between preoperative frontal electroencephalogram alpha asymmetry and postoperative quality of recovery: an observational study"

Summary published April 24, 2023

Summary by Jayashree Sood, MD; Bhuwan Chand Panday, MD

British Journal of Anaesthesia | January 2023

Bae J, Lee JS, Oh J, Han DW, Jung H, Kim SM, Song Y. Association between preoperative frontal electroencephalogram alpha asymmetry and postoperative quality of recovery: an observational study. Br J Anaesth. 2023 Apr;130(4):430-438. doi: 10.1016/j.bja.2022.12.003. Epub 2023 Jan 10. PMID: 36631312.

doi: https://doi.org/10.1016/j.bja.2022.12.003

  • The left frontal alpha asymmetry (LFAA) is known to reflect anxiety and depression. Based on this hypothesis, a prospective observational study was conducted in the Republic of Korea to evaluate the four-channel EEG on the left and right frontal areas. EEG was recorded 20 minutes before surgery to 20 minutes post-surgery. A total of 110 female patients undergoing thyroidectomy with ASA physical status 1 and 2 were recruited. The quality of recovery (QoR-15) score was determined on the day prior to surgery and on postoperative day 1 and 2, using a validated questionnaire including the Big Five Inventory (BFI), Hospital Anxiety Depression Scale (HADS), and Pain Catastrophizing Scale (PCS).
  • The EEG LAB toolbox was used to create a 4-channel EEG topoplot, and patients in the LFAA and right-sided frontal alpha asymmetry (RFAA) groups clearly indicate a difference in the power spectral density of frontal cortex alpha oscillations between the groups. The global QoR 15 scores were 122 (baseline), 52 (POD1), and 104 (POD2) in the LFAA group and 127 (baseline), 113 (POD1), and 123 (POD2) in the RFAA group. Post-hoc analysis revealed significantly lower scores both in POD1 and POD2 in the LFAA group than in the RFAA group. The reduction in scores from the baseline values was also significantly greater in the LFAA group than in the RFAA group on the POD1 and POD2.
  • According to the tertile distribution, LFAA preoperatively was 47% (group 1), 23% (group 2), and 18% (group 3), and the analysis showed that the higher the relative right alpha power, the better the perioperative QoR-15 scores and vice versa.
  • The current study demonstrated a close association between preoperative LFAA and poor QoR after thyroidectomy in female patients. This is the first study to report the feasibility of frontal EEG measurement in predicting patient-centric outcomes after general anesthesia.