The influence of preoperative cognitive impairmenton the changes in the brain's electrical activityin patients 1 year after coronary artery bypassgrafting

Authors: Tarasova I.V., Trubnikova O.A., Kukhareva I.N., Barbarash O.L., Barbarash L.S.

Company: Research Institute for Complex Issues of Cardiovascular Diseases, Sosnovyy bul’var, 6, Kemerovo, 650002, Russian Federation

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Type:  Original articles


For citation: Tarasova I.V., Trubnikova O.A., Kukhareva I.N., Barbarash O.L., Barbarash L.S. The influence of preoperative cognitive impairment on the changes in the brain's electrical activity in patients 1 year after coronary artery bypass grafting. Creative Cardiology. 2018; 12 (4): 304–15 (in Russ.). DOI: 10.24022/1997-3187-2018-12-4-304-315.

Received / Accepted:  26.10.2018/12.11.2018

Keywords: electroencephalography theta rhythm preexisting cognitive impairments coronary artery bypass grafting

Full text:  



Objective. To study the brain electrical activity changes at 1 year after coronary artery bypass grafting (CABG) in patients with and without preoperative cognitive impairment.

Material and methods. Sixty-five patients (aged 45 to 69 years) after CABG were enrolled to the study. All the patients were divided into two groups before surgery: with mild cognitive impairment (MCI) (n=27, Mini mental state examination (MMSE) scores 26.2±0.95) and without MCI (n=38, MMSE scores 28.5±0.69). All patients underwent clinical and neuropsychological examination, as well as multichannel computer electroencephalography (EEG) 3–5 days before surgery and 1 year after CABG. Monopolar EEG recording in the range 0–50 Hz was performed from sixty-two sites according to the international 10–20 system. The EEGs recorded in the resting states with the eyes open and closed.

Results. We revealed that the patients without preexisting cognitive impairment had better cognitive functions at 1 year after CABG as compared with preoperative data (p=0.0007), whereas in the MCI group there was no improvement in cognitive status. MCI patients demonstrated diffuse theta-activity increase with eyes open state (p<0.05), and an alpha activity increase in the left hemisphere with eyes closed in comparison with preoperative EEG values (p=0.01). In addition, the patients with preexisting cognitive impairment had frontal alpha activity increase with eyes open at 1 year after CABG as compared with preoperative values (p<0.05).

Conclusions. It is suggested that the cortical dysfunction detected by computer EEG data at 1 year after CABG may be associated with worse postoperative recovery of cognitive functions in patients with preexisting cognitive impairment.


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About Authors

  • Irina V. Tarasova, Leading Researcher, Cand. Med. Sc.,;
  • Ol’ga A. Trubnikova, Head of Laboratory, Dr Med. Sc.,;
  • Irina N. Kukhareva, Researcher,;
  • Ol’ga L. Barbarash, Corresponding Member of Russian Academy of Sciences, Director,;
  • Leonid S. Barbarash, Chief Researcher, Academician of Russian Academy of Sciences,

Chief Editor

Leo A. Bockeria, MD, PhD, DSc, Professor, Academician of Russian Academy of Sciences, President of Bakoulev National Medical Research Center for Cardiovascular Surgery