Daytime Neurophysiological Hyperarousal in Chronic Insomnia: A Study of qEEG.

Da Young Oh,Su Mi Park,Sung Won Choi

doi:10.3390/jcm9113425

Abstract

Background: The hyperarousal model demonstrates that instability of sleep-wake regulation leads to insomnia symptoms and various neurophysiological hyperarousal states. Previous studies have shown that hyperarousal states that appear in chronic insomnia patients are not limited to sleep at nighttime but are stable characteristics that extend into the daytime. However, this phenomenon is mainly measured at bedtime, so it hard to determine whether it is maintained throughout a 24 h cycle or if it just appears at bedtime. Methods: We examined the resting state qEEG (quantitative electroencephalogram) and ECG (electrocardiogram) of chronic insomnia patients (n = 24) compared to good sleepers (n = 22) during the daytime. Results: As compared with controls, participants with insomnia showed a clearly high beta band activity in eyes closed condition at all brain areas. They showed a low frequency band at the frontal area; high frequency bands at the central and parietal areas were found in eyes open condition. Significantly higher heart rates were also found in the chronic insomnia group. Conclusion: These findings suggest that chronic insomnia patients were in a state of neurophysiological hyperarousal during the middle of the day due to abnormal arousal regulation.

Highlights

In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [1,2], insomnia is defined as a predominant complaint of dissatisfaction with sleep quantity or quality associated with difficulty in initiating sleep, difficulty in maintaining sleep, early morning sleep termination, and fatigue despite sleeping for a sufficient amount of time [2,3]
The purpose of the study was to confirm whether the hyperarousal state of individuals with chronic insomnia was persistent during the day
Patients satisfying the DSM-5 criteria for insomnia without other coexisting mental disorders underwent psychophysiological assessments such as EEG and ECG to identify pathological and neurophysiological factors among those with chronic insomnia

Summary

Introduction

In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) [1,2], insomnia is defined as a predominant complaint of dissatisfaction with sleep quantity or quality associated with difficulty in initiating sleep (i.e., difficulty in falling asleep), difficulty in maintaining sleep (i.e., frequently or continuously awakening during the night), early morning sleep termination (awakening earlier than scheduled in the morning and difficulty falling asleep again), and fatigue despite sleeping for a sufficient amount of time [2,3]. Previous studies suggest that the hyperarousal state observed in patients with chronic insomnia is not limited to sleep during the night but extended to the daytime, which is ‘a 24 h hyperarousal state’. Previous studies have shown that hyperarousal states that appear in chronic insomnia patients are not limited to sleep at nighttime but are stable characteristics that extend into the daytime. This phenomenon is mainly measured at bedtime, so it hard to determine whether it is maintained throughout a 24 h cycle or if it just appears at bedtime. Conclusion: These findings suggest that chronic insomnia patients were in a state of neurophysiological hyperarousal during the middle of the day due to abnormal arousal regulation

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Conclusion