The Correlation Between EEG Power Spectral And Memory In Patients With Chronic Insomnia Disorder

Objective:Chronic insomnia disorder is a prevalent disorder that has not only been linked to impaired psychologic and somatic disease,but also seriously affected the formation and consolidation of memory.Hyperarousal processes from the molecular to the higher system level play a key role in the pathophysiology.Studies have demonstrated that levels of cortical arousal in chronic Insomnia disorder are higher than normal by EEG power spectra.We want to explore the characteristic of EEG power spectra in patients with chronic insomnia disorder and whether it was related to memory function.Methods:Patients with chronic insomnia disorder(CID)according to ICSD-3 and age-matched good sleeper comparison subjects(GSC)were included in the study.Some sleep scales and PSG to measure volunteers' subjective and objective sleep quality;nine-box-maze and Wechsler Memory Scale to evaluate the memory function;EEG power spectra to measure hyperarousal processes.Result:1.There is a significant difference between CID group and GSC group in Hamilton Anxiety Rating Scale(HAMA),the 17-item Hamilton Depression Rating Scale(HAMD-17),the insomnia severity index(ISI).However,the levels of anxiety and depression in both groups were not higher than those of mild anxiety and depression.2.In the results of PSG,a significant difference between CID group and GSC group in total sleep time(TST),sleep latency(SL),REM sleep latency(RL),sleep efficiency(SE),wake after sleep onset(WASO),percentage of N1 sleep(N1%),percentage of N3 sleep(N3%).3.CID group performed poorly in spatial memory,long-term memory,short-term memory,understanding.4.Delta power spectra in REM stage was lower in CID group whereas beta and sigma power spectra in NREM stage were higher in CID group than GSC group.5.N3%has a Negative correlation with mistakes of spatial memory,long-term memory was negatively correlated with the REM stage,as same as the NREM stage and sigma power spectra.Meanwhile,sigma power spectra correlated with SL,WASO,N1%positively.Beta 2 power spectra in the NREM stage was correlated with N1%positively.Delta power spectra in the REM stage was positively correlated with long-term memory and short-term memory.The residual correlation analysis was not statistically significant.Conclusion:The memory function in CID group was impaired.The beta and sigma power spectra in NREM stage were higher than those in the GSC group,and the delta power spectra in REM was reduced compared with the GSC group.The change of memory function is related to the frequency power spectra of EEG.