Insomnia disorder is a common clinical mental disorder.Currently, clinical subtyping of insomnia disorder relies primarily on symptomatic descriptions, lacking objective measures and subtyping-based treatment approaches. In recent years, increasing attention has been drawn to sleep electroencephalography (EEG) as a valuable tool for observing abnormal sleep architecture and continuity of insomnia disorder. Sleep EEG analysis holds the potential to elucidate the underlying biological mechanisms of insomnia disorder, facilitating data-driven subtyping and enhancing personalized therapeutic strategies.Five types of sleep EEG subtypes of insomnia disorder were systematically searched and summarized: classifications derived from objective sleep duration, power spectral characteristics, cyclic alternating pattern, spindle and microarousal.EEG characteristics of each subtype and clinical outcomes are discussed.This review aims to provide evidence-based insights for clinical subtyping and personalized treatment of insomnia disorder.

Objective This study aimed to explore the differences in global and local brain network topological properties between deficient pattern(DP)and excess pattern(EP)of mild vascular cognitive impairment caused by subcortical small vessel disease based on graph theory network.Methods Patients were recruited prospectively and were classified with DP and EP subtype.The global small-world topological attributes and local nodes were calculated for the comparison of DP,EP,and healthy controls(CN)using the GRETNA platform.Results The three groups all had small-world attributes,but only the patients in EP had a significantly lower small world attribute δ in the range of 0.05-0.26 than the control group(P<0.05).The node efficiency and node strength indicators of multiple brain region were able to significantly distinguish the DP group from the EP group.However,there was no positive brain region in the node efficiency of the DP patients(P>0.05),and only a few brain regions showed increased node strength efficiency(P<0.05).Conclusion The results indicate that the syndrome of DP and EP have significantly different neuroimaging phenotypes,providing a basis for further research of biological classification based on Chinese Medicine syndromes.