Repurposing EEG monitoring of general anaesthesia for building biomarkers of brain ageing: An exploratory study

David Sabbagh (1, 2) , Jérôme Cartailler (1, 3) , Cyril Touchard (3) , Jona Joachim (3) , Alexandre Mebazaa (1, 3) , Fabrice Vallée (1, 3, 4) , Étienne Gayat (1, 3) , Alexandre Gramfort (2) , Denis Engemann (2, 5, 6)

1 MASCOT (UMR_S_942 / U942) - Marqueurs cardiovasculaires en situation de stress
2 PARIETAL - Modelling brain structure, function and variability based on high-field MRI data
3 Département d’Anesthésie-Réanimation-SMUR [Hôpital Lariboisière]
4 M3DISIM - Mathematical and Mechanical Modeling with Data Interaction in Simulations for Medicine
5 IMPNSC - Max Planck Institute for Human Cognitive and Brain Sciences [Leipzig]
6 pRED - Roche Pharma Research and Early Development [Basel]

Background: EEG is a common tool for monitoring anaesthetic depth but is rarely reused at large for biomedical research. This study sets out to explore repurposing of EEG during anaesthesia to learn biomarkers of brain ageing. Methods: We focused on brain age estimation as an example. Using machine learning, we reanalysed 4-electrodes EEG of 323 patients under propofol and sevoflurane. We included spatio-spectral features from stable anaesthesia for EEG-based age prediction applying recently published reference methods. Anaesthesia was considered stable when 95% of the total power was below a frequency between 8Hz and 13Hz. Results: We considered moderate-risk patients (ASA <= 2) with propofol anaesthesia to explore predictive EEG signatures. Average alpha-band power (8-13Hz) was informative about age. Yet, state-of-the-art prediction performance was achieved by analysing the entire power spectrum from all electrodes (MAE = 8.2y, R2 = 0.65). Clinical exploration revealed that brain age was systematically linked with intra-operative burst suppression-commonly associated with agerelated postoperative cognitive issues. Surprisingly, the brain age was negatively correlated with burst suppression in high-risk patients (ASA = 3), pointing at unknown confounding effects. Secondary analyses revealed that brain-age EEG signatures were specific to propofol anaesthesia, reflected by limited prediction performance under sevoflurane and poor cross-drug generalisation. Conclusions: EEG from general anaesthesia may enable state-of-the-art brain age prediction. Yet, differences between anaesthetic drugs can impact the effectiveness of repurposing EEG from anaesthesia. To unleash the dormant potential of repurposing EEG-monitoring for clinical and health research, collecting larger datasets with precisely documented drug dosage will be key enabling factors.

Mots clés: general anaesthesia; electroencephalogram (EEG); brain ageing; machine learning; burst suppression; propofol; sevoflurane

Domaines: Neurosciences [q-bio.NC]; Médecine humaine et pathologie

David Sabbagh, Jérôme Cartailler, Cyril Touchard, Jona Joachim, Alexandre Mebazaa, et al.. Repurposing EEG monitoring of general anaesthesia for building biomarkers of brain ageing: An exploratory study. 2022. ⟨hal-03671308⟩