Sleep EEG characteristics associated with total sleep time misperception in young adults
Abstract Backgroud: Power spectral analysis (PSA) is one of the most commonly-used EEG markers of cortical hyperarousal which help to understand subjective-objective sleep discrepancy (SOD). Age is associated with decreased sleep EEG activity. Currently, PSA of young adults are limited. Thus, this study aimed to examine the correlation of spectral EEG power with total sleep time misperception in young patients. Methods : Forty-seven young adults were recruited and underwent a polysomnography recording in a sleep laboratory. The clinical records and self-report questionnaires of all patients were collected, who were categorized into the GS (n=10), insomnias with a low mismatch (IWLM, n=19) and participants with a high mismatch (IWHM, n=18) subgroups. Power spectral analysis was performed during the first 6 hours of sleep. Results : The IWLM group showed increased absolute beta power in central-frontal area and relative beta power in frontal areas compared to the GS group. In addition, IWHM patients exhibited higher absolute and relative beta power in the central area compared to the GS group. The absolute and relative beta/delta ratios in frontal area in the IWHM and IWLM groups were higher than those in the GS group. The IWHM group also showed higher absolute and relative beta/delta ratios in the central area compared with the GS group. No significant difference in the above parameters was observed between the IWHM and IWLM groups. Moreover, the SOD of TST was negatively correlated with the relative delta power (r=0.289, p=0.049), beta power (r=0.373, p=0.010), beta/delta ratio(r= 0.314, p=0.032), and the absolute beta/delta ratio (r=0.314, p=0.032) in central area. Conclusions: Young IWHM and IWLM patients showed increased beta EEG power compared to GS, suggesting that there exists increased cortical activity in these patients. Also, the beta/delta ratio was negatively correlated with the SOD in patients with IWHM and IWLM.