THE IMPACT OF MILD COGNITIVE IMPAIRMENT ON THE BIOELECTRIC ACTIVITY OF BRAIN IN PATIENTS AFTER ON-PUMP CORONARY ARTERY BYPASS GRAFTING

Abstract

Background: Neurological complications after on-pump cardiac surgery are one of the most important unsolved problems of modern cardiac surgery. The patients with mild cognitive impairment (MCI) may be a group with a high risk of ischemic changes in the brain and progression of cognitive impairment induced by cardio-pulmonary bypass. Non-invasive neuromonitoring can reveal subclinical symptoms and topography of cerebral ischemia. Purpose: To study the topography of the spectral EEG power in coronary artery disease (CAD) patients with or without MCI before and after on pump CABG. Materials and Methods: Fifty three (53) males (age 47–68 years) were divided into two groups: with MCI (n = 19, MMSE score – 26,3±0,95) and without MCI (MMSE score – 28,5±0,79, n=34). Monopolar EEGs were recorded 3–5 days before and 7–10 days after surgery in 62 sites of 10-20 system. The EEG power was calculated in frequency ranges of 4–30 Hz. Results: All patients’ demonstrated theta1 and beta1 power increase in 7–10 days after CABG compared to preoperative values. The topographic distribution of EEG changes was different in MCI and non-MCI groups: the patients with MCI had more prominent cortical dysfunction in the frontal and central regions. Conclusions: The cortical dysfunction in the frontal brain areas can be associated with the progression of cognitive deficit, worsening social and household adaptation in CAD patients with MCI.