OBJECTIVE: To approach the evaluation of relative α variant score monitored by bedside continuous electroencephalography and optic nerve sheath diameter (ONSD) evaluated by ultrasound in patients with ischemic hypoxic encephalopathy, and to observe the effect of neurofeedback training on brain function. METHODS: A prospective observational study was conducted. The patients admitted to the emergency and intensive care department of Shanghai Pudong New Area People's Hospital from January 2021 to December 2023, who meet the diagnostic criteria of ischemic hypoxic encephalopathy with the Glasgow coma score (GCS) ≤ 8 at admission receiving neurofeedback training were enrolled as the study object (observation group), and the patients without neurofeedback training and GCS score ≤ 8 at admission were enrolled as the controls (control group). Both groups received intravenous neurotrophic therapy combining ganglioside and cerebrolysin for 10 days as one course of treatment. On this basis, the observation group additionally received continuous neurofeedback training including visual feedback, auditory feedback, meditation and relaxation for 14 days. Bedside continuous electroencephalography was used for monitoring relative α variation score, and ultrasound was used to determine ONSD. The average power and slow wave power [expressed as delta-theta ratio (DTR)] of five channels in electroencephalography before and 14 days after neurofeedback training were examined. The differences in peripheral blood neutrophil/lymphocyte ratio (NLR), Hamilton depression scale (HAMD) score, National Institutes of Health stroke scale (NIHSS) score, plasma levels of 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor (BDNF). RESULTS: A total of 60 patients were enrolled in the observation group and 50 patients in the control group finally. There was no significant difference in gender, age or course of disease between the two groups. The ONSD and relative α variant score in the observation group were significantly higher than those in the control group [ONDS (mm): 5.59±0.42 vs. 3.23±0.34, relative α variant score: 2.28±0.39 vs. 0.83±0.28, both P <
0.01]. After neurofeedback training for 14 days, the mean power and DTR in five channels of electroencephalography in the observation group were significantly lower than those before treatment [mean power (μV CONCLUSIONS: Both ONDS determined by ultrasound and relative α variation score monitored by electroencephalography changed significantly in the patients with ischemic hypoxic encephalopathy. Neurofeedback training can effectively improve brain function in patients with ischemic hypoxic encephalopathy.