Efficiency of using a neurofeedback device in determining ischaemic early electroencephalography indicators in rabbits with acute brain ischaemia

Abstract

OBJECTIVES: Continuous electroencephalography (EEG) monitoring is a useful method in surgical procedures in which brain circulation is at risk. Providing this function using neurofeedback devices reduced to small dimensions may provide ease of use in the early diagnosis of brain ischaemia. The goal of this study was to demonstrate the efficiency of using a neurofeedback device in determining the early EEG indicators of ischaemia in a rabbit model of acute brain ischaemia.

METHODS: Three randomized groups-carotid ischaemia (CI), global ischaemia (GI) and a sham group-each comprising 8 rabbits, were created. In the CI group, the bilateral main carotid artery was clamped; in the GI group, the bilateral subclavian and main carotid arteries were clamped and brain ischaemia was created for 15 min. Brain reperfusion was then achieved for 30 min. In the sham group, the same surgical preparation was performed but no ischaemia occurred. The brain EEG wave activities of all subjects were recorded during the experiment. At the end of the procedure, all brain tissue was removed and apoptotic indexes were determined by histopathological examination. The statistical significance of the histopathological results and the EEG wave activities among the groups was examined.

RESULTS: There was a significant difference between the sham, CI and GI average amplitude ratios, delta (1.02, 0.69, 0.16; P < 0.001) and total wave (0.99, 0.78, 0.49; P < 0.001), respectively. There was no significant difference between the sham and CI groups in delta (sham, CI, 1.01, 0.87; P = 0.1), total wave (sham, CI, 1.22, 0.98; P= 0.2) and amplitude standard deviation rates. However, there was a significant difference in the GI group (P < 0.001). There was a significant difference between all groups in apoptotic index (sham, 17.88; CI, 40.75; GI, 55.88; P < 0.001).

CONCLUSIONS: Significant EEG wave changes resulting from experimental brain ischaemia were analysed with the use of a neurofeedback device. The results indicated that the change in the delta and the total wave standard deviations may be an additional indicator in the formation of permanent brain damage.