关键词: 睡眠呼吸暂停综合征, 脑电波, 睡眠纺锤波, 快速眼动睡眠, 非快速眼动睡眠

Abstract: Background　Obstructive sleep apnea-hypopnea syndrome （OSAHS） is one of the common sleep disorders.Previous studies demonstrate that change of sleep structure and decline of cognitive function are more likely to appear in older patients，with reasons incompletely determined yet.Up to now，there are few studies focusing on the relationship of the sleep electroencephalogram （EEG） and sleep structure with OSAHS patients at different ages.Objective　To explore the characteristics of sleep EEG of patients with severe OSAHS by age，so as to further provide significant information about brain plasticity change for instructing clinical treatment.Methods　In the study，67 patients definitely diagnosed with severe OSAHS from June 2017 to March 2018 in the Sleep Disordered Breathing Diagnosis and Therapy Center，Peking University Shenzhen Hospital were selected and were divided into the younger group （18-40 years old，n=34） and the older group （41-65 years old，n=33） based on the latest national age classification standard.We compared the two groups in the aspects of apnea-hypopnea index （AHI），the lowest SpO2 （LSpO2） during the night，sleep efficiency，the percentage of sleep time during various non-rapid eye movement （NREM） sleep stages （N1，N2 and N3），and the percentage of rapid eye movement （REM） sleep period in the total sleep time，electroencephalograph power density of various waves 〔EEG-δ （0.5-4.0 Hz），EEG-θ（4.1-8.0 Hz），EGG-α（8.1-12.0 Hz） and EGG-β （12.1-30.0 Hz）〕 during NREM period，and analyzed the correlation of electroencephalograph power density during NREM，sleep time in REM period and sleep efficiency with AHI.Results　As for the percentage of the sleep time during various stages in the total sleep time，it was higher during N1 and N2 stages in the older group than in the younger group，while was lower in N3 and REM period in the older group than in the younger group （P<0.05）.During the stages of N1，N2 and N3，the power densities of EEG-δ of patients in the older group were lower than those of patients in the younger group （P<0.05）.The power density of EEG-θ of patients in the older group was lower than that of those in the younger group during N3 stage （P<0.05）.During the stages of N2 and N3，the power densities of EEG-α of patients in the older group were lower than those of patients in the younger group （P<0.05）.During the stages of N1，N2 and N3，the power densities of EEG-β of patients in the older group were higher than those of patients in the younger group （P<0.05）.For the patients in the younger group，the correlation of the power density of EEG-δ，EGG-θ and EEG-α，the sleep time during REM period and the sleep efficiency with AHI was negative （r=-0.338，-0.315，-0.383，-0.483 and-0.501，respectively，P<0.05）；the power density of EEG-β during NREM period of younger group patients had no linearity correlation with AHI（P>0.05）.For the patients in the older group，the power density of various waves during NREM period，the sleep time during REM period and the sleep efficiency had no linearity correlation with AHI （P>0.05）.Conclusion　There are significant differences between the EEG performance of the younger and older patients with severe OSAHS.The older patients have longer N1 and N2-stage sleep time with shorter N3 and REM-sleep time；compared to the younger group，the EEG-δ during NREM period，EEG-θ and EEG-αduring N3 stage are found to decrease while EEG-β during NREM period is found to increase.All the EEG changes lead to the reduction of deep sleep time and the increase of shallow sleep time for the older patients with severe OSAHS.Consequently，they are easier to wake when coming across external stimuli and intermittent hypoxia，which directly lead to the increase of sleep fragmentation.

Key words: Sleep apnea syndromes, Brain waves, Sleep spindle wave, Rapid eye movement sleep, Non-rapid eye movement sleep