The Neuroelectric Activity of The Brain in Extracorporeal Circulation: Preliminary Results


  • Turan Onur Bayazıt

Received Date: 28.07.2018 Accepted Date: 08.08.2018 Med J Bakirkoy 2018;14(4):427-432


The use of a cardiopulmonary machine during cardiac surgery causes a non-physiological circulation in the brain and the other body organs. This situation usually causes brain ischemia. Due to this or other factors, neurological disorders such as stroke and psychiatric disorders are encountered during the perioperative period. In this study, it was aimed to compare neuroelectrical activity measured during extracorporeal circulation in coronary bypass surgery with preoperative values of the patient.

Materials and Methods:

Six male patients who underwent coronary artery bypass surgery in cardiovascular surgery participated in the study. Both the preoperative (PrO) and during operation (InO) electroencephalography (EEG) data obtained from the frontal region. The delta (δ; 0.5-3.5 Hz), theta (θ; 3.5-7 Hz), alpha (α; 8-14 Hz), beta (β; 15-30 Hz) ve gamma (γ; 30-48 Hz) frequency power components were calculated. An equal number of PrO and InO period EEG power values from each participant were taken and used for statistical analysis. Results with a p-value of less than 0.05 were considered statistically significant.


The main finding of the study is that the frequency power spectrum values show a decrease in the extracorporeal circulation. When the percentage reduction is compared, it is seen that the fast frequencies decrease at a statistically significant with respect to the slow frequencies.


Changes in the EEG frequencies of this preliminary study indicate that brain functions are reduced during extracorporeal circulation. In a broader group of patients, the study included a multi-channel EEG, as well as near-infra-red spectroscopy for cortical blood flow monitoring and the addition of neurocognitive assessment tests, will give us some indicator parameters calculated by meta-analyses from all these data. Early detection of the brain damage and take precaution may be achieved with this indicator data.

Keywords: Electroencephalography, neuroelectrical activity, delta, alpha, theta, beta, gamma, extracorporeal circulation

Full Text (Turkish)