以腦波及心律變異性分析為基礎之失眠評估

Assessment of Insomnia Based on EEG and Heart Rate Variability Analysis

失眠已成為現代人嚴重的健康問題，因此了解失眠者的生理表現差異，以協助臨床睡眠的治療，實為重要的工作。許多文獻已經顯示睡眠分期與腦波(Electroencephalogram; EEG)及心律變異性(Heart Rate Variability; HRV)具有關聯性，低頻(Low Frequency; LF)在快速動眼期(Rapid Eye Movement; REM) 較顯著，高頻(High Frequency; HF)則在非快速動眼期(Non-Rapid Eye Movement; NREM)較顯著，但是失眠者是否與正常者有不一樣的腦波功率及心律變異性。因此本研究希望透過失眠者的腦波和心律變異性進行分析，以了解失眠的可能原因。本研究由某醫學中心取得正常11人與失眠14人的多項睡眠生理檢查(Polysomnography; PSG)，並將睡眠的腦波與心率變異性資料分為快速動眼期與非快速動眼期、快波期與慢波期加以比較分析。結果顯示幾個重要發現，在正常者中低頻、標準化低頻(normalized Low Frequency; LF(nu))及低頻比高頻值 (LF/HF ratio)有顯著的差異，低頻、標準化低頻、低頻比高頻值在REM期顯著大於NREM期，但失眠者卻沒有此差異。正常者的beta波在快速動眼期時顯著大於非快速動眼期時，而在失眠期卻是快速動眼期時顯著小於非快速動眼期時。正常者的delta波在快速動眼期顯著小於非快速動眼期，而在失眠者中，並無此差異。在一些睡眠分期中失眠者的心率變異性與腦波的特徵確實有與正常者有所不同，也許是個能夠深入探討的問題。

Insomnia has become a severe health problem recently. So analyzing the physiological differences in sleep between insomnia and normal people to assist clinical treat is an important work. Some researches indicate that sleep stage is related with electroencephalogram(EEG) and heart rate variability (HRV). Low frequency power of HRV is obvious in Rapid Eye Movement (REM), in contrast high frequency power of HRV is more dominant in Non-Rapid Eye Movement (NREM). But few researches investigate whether sleep disorder has different EEG and HRV or not. The goal of this study is to reveal the differences of EEG and HRV between insomnia and normal subjects and give some reasonable explanation for sleep disorder. We obtained polysomnography (PSG) data of 11 normal subjects and 14 insomnia cases from a sleep center in a hospital. The data according to sleep staging algorithm were divided into REM and NREM periods, in addition to fast wave and slow wave periods in NREM stage. The results revealed that LF(Low Frequency; LF)„ LF(nu) (normalized Low Frequency; LF(nu)) and LF/HF (LF/HF ratio ) were significantly lower respectively in NREM comparing with those in REM for normal subjects, but no significant differences in insomnia cases. In EEG, the power of beta wave in normal subjects was significantly increased in REM than in NREM, but it appeared an opposite result in insomnia cases. Moreover, the normal subjects had stronger delta wave power at NREM stage, but this difference didn't exist in insomnia cases. Therefore insomnia indeed displayed abnormal regulation in autonomic control and brain activity for sleep process in this study. This finding may provide a new direction to understand insomnia.